Note: Descriptions are shown in the official language in which they were submitted.
NON-INVASIVE EPIDERMAL HEALTH-MONITORING SENSOR, PATCH
SYSTEM AND METHOD, AND EPIDEMIOLOGICAL MONITORING AND
TRACKING SYSTEM RELATED THERETO
FIELD OF THE DISCLOSURE
100011 The present disclosure relates to health-monitoring systems, and, in
particular,
to a non-invasive epidermal health-monitoring sensor, patch, system and
method, and
epidemiological monitoring and tracking system related thereto.
BACKGROUND
100021 Hospital-grade health monitoring equipment encompasses a gamut of
sensors
and monitoring systems designed to specifically probe and address various
health markers
in different medical context, such as surgical, emergency and intensive care
units. A
critically ill patient may be fitted with a standard pulse oximeter clip on
their finger to
monitor variations in blood oxygen saturation, and electrocardiograph probes
for cardiac
monitoring and related vital signs. Regular body temperature readings may also
be taken
by medical staff using handheld, and recently contactless, thermometers.
100031 In some recent developments, as reported by Chung et al. in the
article "Binodal,
wireless epidermal electronic systems with in-sensor analytics for neonatal
intensive care",
Science 363, 947 (2019), the entire contents of which are hereby incorporated
herein by
reference, respective ECG / temperature and PPG / temperature epidermal
sensors have
been proposed for neonatal intensive care units.
100041 While such equipment and practices may become commonplace and
practical
in a hospital or critical care setting, their general cost, size in standard
bedside equipment,
and ofttimes complex operation make them inadequate for residential or
widespread use
amongst non-medical staff.
100051 Accordingly, in the context of home treatment or monitoring, for
instance, when
addressing residential patients or again dealing with imposed or recommended
public self-
isolation, quarantine, or like considerations as applicable in a local or
regional outbreak or
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epidemic, or outright pandemic, such equipment becomes unreasonable, leaving
individuals empty-handed to track their conditions beyond basic symptom
progression
tracking and use of standard household devices like a handheld thermometer.
100061 Furthermore, efforts for the mass collection and compilation of
home care,
national or even global medical health care data for statistical analysis or
epidemiological
tracking are generally challenged by inaccurate or inconsistent data
collection at best,
leading to potentially questionable, incomplete or inaccurate results.
100071 This background information is provided to reveal information
believed by the
applicant to be of possible relevance. No admission is necessarily intended,
nor should be
construed, that any of the preceding information constitutes prior art or
forms part of the
general common knowledge in the relevant art.
SUMMARY
100081 The following presents a simplified summary of the general
inventive
concept(s) described herein to provide a basic understanding of some aspects
of the
disclosure. This summary is not an extensive overview of the disclosure. It is
not intended
to restrict key or critical elements of embodiments of the disclosure or to
delineate their
scope beyond that which is explicitly or implicitly described by the following
description
and claims.
100091 A need exists for a health-monitoring sensor, system and method,
such as a non-
invasive epidermal health-monitoring sensor, patch, system and method, and/or
an
epidemiological monitoring and tracking system related thereto, that overcome
some of the
drawbacks of known techniques, or at least, provides a useful alternative
thereto. In
particular, some aspects of the herein described embodiments provide a
relatively
affordable and non-medical user-friendly device and/or system to track health-
related
variables in a non-medical context, for example, at home, in a residence, in
self-isolation
or under prescribed or recommended social distancing environments, in large-
scale
quarantine centers or the like.
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100101 A need also or alternatively exists for a broad spectrum oximetry
device, system
and method that overcome some of the drawbacks of known oximetry solutions, or
at least,
provide a useful alternative thereto. Examples of such systems, devices and
methods are
disclosed herein, in accordance with difference embodiments.
100111 In accordance with some aspects, there is provided a patient health
monitoring
system comprising: an epidermal device to be affixed to the patient's skin and
comprising:
an optical spectroscopy probe operable to acquire data representative of blood
oxygenation
levels; and a wireless interface; a mobile application operable on a mobile
device to
interface with said wireless interface and receive therefrom said acquired
data; stored
computer-executable code operable by a digital processor to monitor for
variations in said
blood oxygenation levels and digitally evaluate said variations against preset
variations
corresponding to benchmark blood oxygenation profiles, wherein said profiles
are digitally
associated with a preset blood oxygenation index defining at least a lower
health risk rating
and a higher health risk rating, and output a signal representative of said
higher health risk
rating in response to said evaluation.
100121 In one embodiment, the blood oxygenation levels comprise
deoxyhemoglobin
concentrations, and wherein said benchmark blood oxygenation profiles
comprises
deoxyhemoglobin concentration profiles.
100131 In one embodiment, blood oxygenation levels comprise respective
deoxyhemoglobin concentrations and oxidized hemoglobin concentrations, and
wherein
said benchmark blood oxygenation profiles comprise dissolved oxygen profiles
derived
from said concentrations.
100141 In one embodiment, blood oxygenation levels comprise both
arterial and venous
blood oxygenation levels.
100151 In one embodiment, the stored computer-executable code is stored on
said
mobile device and operable by said mobile application.
100161 In one embodiment, the stored computer-executable code is stored
on a server
communicatively accessible by said mobile application via said mobile device.
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100171 In one embodiment, the system further comprises a remote server
operatively
linked to said mobile application to process acquired data from multiple users
in
continuously or periodically optimizing said benchmark profiles accordingly.
100181 In one embodiment, the system further comprises a remote server
operatively
linked to said mobile application to process acquired data from multiple users
in
continuously or periodically updating a global health-related tracking.
100191 In one embodiment, the epidermal device comprises an integrated
epidermal
patch further comprising a body temperature sensor.
100201 In one embodiment, the system for monitoring a user supported by
an oxygen-
providing apparatus.
100211 In one embodiment, the system for monitoring a user exposed to
partial oxygen
pressures deviating from a standard value of about 0.21 atm at Standard
Temperature and
Pressure (STP).
100221 In one embodiment, the epidermal device comprises a cerebral
device to be
affixed to the user's head.
100231 In one embodiment, the optical spectroscopy probe comprises a
broad-spectrum
oximetry probe comprising: a broad-spectrum light source providing broad-
spectrum
illumination to said user body region in probing multiple blood-related
chromophores
exhibiting distinguishable spectral responses; and a spectrometer operable to
acquire an
optical signal from said user body region resulting from said broad-spectrum
illumination
so to digitally capture said distinguishable spectral responses, wherein said
blood-related
chromophores are representative of said blood oxygenation levels; wherein said
stored
computer-executable code is operable by said digital processor to spectrally
resolve said
distinguishable spectral responses from said optical signal to isolate a
spectral signature for
a designated chromophore; and compare said isolated spectral signature with a
designated
set of corresponding signatures associated with a discriminable health-related
condition;
and output said signal representative of said higher health risk rating in
response to said
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evaluation of said health-related indicator representative of said
discriminable health-
related condition.
100241 In one embodiment, the digital processor is operable to extract
an absolute
concentration for said designated chromophore from said spectral signature.
100251 In one embodiment, the broad-spectrum light source emits light in a
range of
about 600 nm to about 1000 nm.
100261 In one embodiment, the spectrometer is operable to isolate
respective spectral
responses within at least 10 spectral regions within said broad-spectrum
illumination.
100271 In one embodiment, the chromophores comprise at least three of
carbon
monoxide, melanin, cytochrome oxidase, oxyhemoglobin, or deoxyhemoglobin.
100281 In one embodiment, the discriminable health-related condition
comprises at
least one of: blood or tissue oxygenation, pulse, blood pressure, blood flow
rate, blood loss
or hemorrhaging, onset of blackouts or change in cognition, lung efficiency,
rate of oxygen
consumption by an organ of interest, psychological or physiological stress,
presence of
stroke, or a change in vital signs.
100291 In one embodiment, the digital processor is operable to isolate a
combined
spectral signature for a designated combination of chromophores; and compare
said
isolated combined spectral signature with a designated set of corresponding
combined
signatures associated with said discriminable health-related condition.
100301 In accordance with another aspect, there is provided a geographical
health
monitoring system comprising: a centralized health-monitoring server; a set of
wearable
health-monitoring devices to be affixed to respective users within a
geographical area to:
acquire health-related data from each of said respective users over time;
concurrently track
a location of each of said respective users; and communicate information
related t said
.. health-related data and said location to said centralized health-monitoring
server for
tracking; wherein, for each of said respective users, said health-related data
is digitally
compared with a designated health-related profile associated with a designated
medical
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condition to automatically output a health risk indicator for a given location
upon given
health-related data acquired at said given location substantially aligning
with said
designated health-related profile.
100311 In one embodiment, a geographical outbreak is automatically
identified upon a
group of said health risk indicators are output for a given area around a same
said given
location.
100321 In one embodiment, infection transmissions are automatically
tracked by
tracking a geographical evolution of said health risk indicators over time.
100331 In one embodiment, the geographical tracking of asymptomatic
users is
automatically implemented and retroactively evaluated by a digital processor
upon any of
said asymptomatic users later triggering a said health risk indicator so to
track potential
retroactive geographical infection transmission from said asymptomatic users.
100341 In one embodiment, the designated health-related profile
comprises a
combination of at least two of a designated body temperature threshold, a
blood oxygen-
concentration related threshold or profile, a respiration rate or variation
profile, a cardiac
rate or variation profile, or a blood pressure or variation profile.
100351 In one embodiment, each of said a set of wearable health-
monitoring devices
comprises an epidermal device to be affixed to the patient's skin and
comprising: an optical
spectroscopy probe operable to acquire data representative of blood
oxygenation levels;
wherein the system further comprises stored computer-executable code operable
by a
digital processor to monitor for variations in said blood oxygenation levels
and digitally
evaluate said variations against preset variations corresponding to benchmark
blood
oxygenation profiles, wherein said profiles are digitally associated with a
preset blood
oxygenation index defining at least a lower health risk rating and a higher
health risk rating
.. associated with said designated medical condition.
100361 In one embodiment, the optical spectroscopy probe comprises a
broad-spectrum
oximetry probe comprising: a broad-spectrum light source providing broad-
spectrum
illumination to said user body region in probing multiple blood-related
chromophores
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exhibiting distinguishable spectral responses; and a spectrometer operable to
acquire an
optical signal from said user body region resulting from said broad-spectrum
illumination
so to digitally capture said distinguishable spectral responses, wherein said
blood-related
chromophores are representative of said blood oxygenation levels; wherein said
stored
computer-executable code is operable by said digital processor to spectrally
resolve said
distinguishable spectral responses from said optical signal to isolate a
spectral signature for
a designated chromophore; and compare said isolated spectral signature with a
designated
set of corresponding signatures associated with said designated medical
condition.
100371 In accordance with another aspect, there is provided an oximetry
system for
monitoring a health-related condition in a user, the system comprising: a
broad-spectrum
oximetry probe fixable to a user body region, the probe comprising: a broad-
spectrum light
source providing broad-spectrum illumination to said user body region in
probing multiple
blood-related chromophores exhibiting distinguishable spectral responses; and
a
spectrometer operable to acquire an optical signal from said user body region
resulting
from said broad-spectrum illumination so to digitally capture said
distinguishable spectral
responses; a digital data processor operatively connected to said broad-
spectrum oximetry
probe, and programmed to: spectrally resolve said distinguishable spectral
responses from
said optical signal to isolate a spectral signature for a designated
chromophore; and
compare said isolated spectral signature with a designated set of
corresponding signatures
associated with a discriminable health-related condition; and output a health-
related
indicator representative of said discriminable health-related condition.
100381 In one embodiment, the digital processor is operable to extract
an absolute
concentration for said designated chromophore from said spectral signature.
100391 In one embodiment, the digital processor is operable to extract a
variation in
said spectral signature over time and compare said variation with said set of
corresponding
signatures to output said health-related indicator.
100401 In one embodiment, the broad-spectrum light source comprises a
full spectrum
infrared (IR) light source.
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100411 In one embodiment, the broad-spectrum light source emits light in
a range of
about 600 nm to about 1000 nm.
100421 In one embodiment, the spectrometer is operable to isolate
respective spectral
responses within at least 10 spectral regions within said broad-spectrum
illumination.
100431 In one embodiment, the spectrometer is operable to isolate
respective spectral
responses within at least 40 spectral regions within said broad-spectrum
illumination.
100441 In one embodiment, the spectrometer is operable to isolate
respective spectral
responses within at least 80 spectral regions within said broad-spectrum
illumination.
100451 In one embodiment, the user body region comprises a cerebral
region.
100461 In one embodiment, the broad-spectrum oximetry probe is integrated
within a
headband.
100471 In one embodiment, the chromophores comprise at least three of
carbon
monoxide, melanin, cytochrome oxidase, oxyhemoglobin, or deoxyhemoglobin.
100481 In one embodiment, the discriminable health-related condition
comprises at
least one of: blood or tissue oxygenation, pulse, blood pressure, blood flow
rate, blood loss
or hemorrhaging, onset of blackouts or change in cognition, lung efficiency,
rate of oxygen
consumption by an organ of interest, psychological or physiological stress,
presence of
stroke, or a change in vital signs.
100491 In one embodiment, the digital processor is operable to isolate a
combined
spectral signature for a designated combination of chromophores; and compare
said
isolated combined spectral signature with a designated set of corresponding
combined
signatures associated with said discriminable health-related condition.
100501 In accordance with another aspect, there is provided an oximeter
for monitoring
a health-related condition, the oximeter comprising: a broad-spectrum light
source for
providing broad-spectrum illumination to a user body region in probing
multiple blood-
related chromophores exhibiting distinguishable spectral responses; and a
spectrometer
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operable to acquire an optical signal from said user body region resulting
from said broad-
spectrum illumination so to digitally capture said distinguishable spectral
responses.
100511 In one embodiment, the broad-spectrum light source comprises a
broadband
infrared (IR) light source.
100521 In one embodiment, the broadband light source emits light in a range
of about
600 nm to about 1000 nm.
100531 In one embodiment, the spectrometer is operable to isolate
respective spectral
responses within at least 10 spectral regions within said broadband
illumination.
100541 In one embodiment, the spectrometer is operable to isolate
respective spectral
responses within at least 40 spectral regions within said broadband
illumination.
100551 In one embodiment, the spectrometer is operable to isolate
respective spectral
responses within at least 80 spectral regions within said broadband
illumination.
100561 In one embodiment, the oximeter is integrated within a headband.
100571 In accordance with another aspect, there is provided a non-
transitory computer-
readable medium comprising digital instructions to be implemented by one or
more digital
processors to monitor one or more health-related parameters in a user, by:
activating a
broadband light source providing broadband illumination to a user body region
in probing
multiple blood-related chromophores exhibiting distinguishable spectral
responses;
acquiring, via a spectrometer, an optical signal from said user body region
resulting from
said broadband illumination so to digitally capture said distinguishable
spectral responses;
spectrally resolving said distinguishable spectral responses from said optical
signal to
isolate a spectral signature for a designated chromophore; comparing said
isolated spectral
signature with a designated set of corresponding signatures associated with a
discriminable
health-related condition; and outputting a health-related indicator
representative of said
discriminable health-related condition.
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100581 In one embodiment, the spectrally resolving comprises resolving
respective
optical signals within at least 10 distinct wavelength regions.
100591 In one embodiment, the spectrally resolving comprises resolving
respective
optical signals within at least 40 distinct wavelength regions.
100601 In one embodiment, the spectrally resolving comprises resolving
respective
optical signals within at least 80 distinct wavelength regions.
100611 In one embodiment, the instructions are operable to extract an
absolute
concentration for said designated chromophore from said spectral signature.
100621 In one embodiment, the instructions are operable to extract a
variation in said
spectral signature over time and compare said variation with said set of
corresponding
signatures to output said health-related indicator.
100631 Other aspects, features and/or advantages will become more apparent
upon
reading of the following non-restrictive description of specific embodiments
thereof, given
by way of example only with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE FIGURES
100641 Several embodiments of the present disclosure will be provided,
by way of
examples only, with reference to the appended drawings, wherein:
100651 Figure 1 is a schematic diagram of a non-invasive epidermal
health-monitoring
sensor and system, in accordance with one embodiment.
100661 Figure 2 is a diagram of a monitoring method using the system of
Figure 1, in
accordance with one embodiment.
100671 Figure 3 is an exemplary plot of the change in time of the relative
absorbance
of deoxyhemoglobin as measured by NIRS of an individual breathing a series of
different
gas mixtures containing lower than normal concentrations of oxygen (hypoxic
mix), in
accordance with one embodiment.
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100681 Figure 4 is an exemplary plot of the change in time of the
relative absorbance
of deoxyhemoglobin as measured by NIRS of an individual breathing a series of
different
gas mixtures containing higher than normal concentrations of oxygen (hyperoxic
mix), in
accordance with one embodiment.
100691 Figure 5 is an exemplary plot of the change in time of the relative
absorbance
of both oxyhemoglobin and deoxyhemoglobin as measured by NIRS of an individual
breathing normal air, an hyperoxic mix and normal air again, while changing
position from
a sitting position, a supine position and a sitting position again, in
accordance with one
embodiment;
100701 Figure 6 is an exemplary plot of the change in time of the relative
molar
concentration of cerebral deoxyhemoglobin as measured by NIRS of an individual
breathing different gas mixtures and immersed in water at different depths, in
accordance
with one embodiment;
100711 Figure 7 is an exemplary plot of the relative change in
concentration of cerebral
deoxyhemoglobin as measured by NIRS of an individual breathing different gas
mixtures
inside a hyperbaric chamber, in accordance with one embodiment;
100721 Figure 8 is an exemplary plot of the relative change in time of
the concentration
of cerebral deoxyhemoglobin as measured by NIRS of an individual both changing
positions (sitting or supine) and breathing different gas mixtures inside a
hyperbaric
chamber, in accordance with one embodiment;
100731 Figure 9 shows three exemplary plots illustrating the relative
change over time
in the concentration of cerebral deoxyhemoglobin; the heart rate and the
breathing or
respiration rate, from top to bottom respectively, of a user engaging in an
underwater
physical activity as a function of time, in accordance with one embodiment;
100741 Figure 10 shows a diagram of another method for monitoring a user's
health
risk for a user using an oxygen providing apparatus and/or inside a sealed
pressurized
environment, in accordance with one embodiment;
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100751 Figure 11 is a schematic diagram of a broad or full spectrum
oximetry
(spectroximetry) system, in accordance with one embodiment;
100761 Figure 12 is a schematic diagram of an exemplary software
processing system,
in accordance with one embodiment;
100771 Figure 13 is a process flow diagram illustrating a monitoring method
for
assessing certain physiological parameters using the system of Figure 1, in
accordance with
some embodiments;
100781 Figure 14 is an exemplary plot of a spectral variation measured
in a user
breathing normal air while sitting in a chair, in accordance with one
embodiment;
100791 Figure 15 is an exemplary plot of an average change in recorded
spectra when
switching from normal air (21% 02) to a hypoxic gas containing 5% 02, in
accordance
with one embodiment;
100801 Figure 16 is an exemplary plot of an average change in recorded
spectra when
switching from normal air (21% 02) to breathing pure oxygen (100% 02), in
accordance
with one embodiment; and
100811 Figure 17 is a diagram of an epidemiological monitoring and
tracking system
operable at least in part, in one embodiment, in concert with or as part of
the health
monitoring system of Figure 1.
100821 Elements in the several figures are illustrated for simplicity
and clarity and have
not necessarily been drawn to scale. For example, the dimensions of some of
the elements
in the figures may be emphasized relative to other elements for facilitating
understanding
of the various presently disclosed embodiments. Also, common, but well-
understood
elements that are useful or necessary in commercially feasible embodiments are
often not
depicted in order to facilitate a less obstructed view of these various
embodiments of the
present disclosure.
DETAILED DESCRIPTION
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100831 Various implementations and aspects of the specification will be
described with
reference to details discussed below. The following description and drawings
are
illustrative of the specification and are not to be construed as limiting the
specification.
Numerous specific details are described to provide a thorough understanding of
various
implementations of the present specification. However, in certain instances,
well-known or
conventional details are not described in order to provide a concise
discussion of
implementations of the present specification.
100841 Various apparatuses and processes will be described below to
provide examples
of implementations of the system disclosed herein. No implementation described
below
limits any claimed implementation and any claimed implementations may cover
processes
or apparatuses that differ from those described below. The claimed
implementations are
not limited to apparatuses or processes having all of the features of any one
apparatus or
process described below or to features common to multiple or all of the
apparatuses or
processes described below. It is possible that an apparatus or process
described below is
not an implementation of any claimed subject matter.
100851 Furthermore, numerous specific details are set forth in order to
provide a
thorough understanding of the implementations described herein. However, it
will be
understood by those skilled in the relevant arts that the implementations
described herein
may be practiced without these specific details. In other instances, well-
known methods,
procedures and components have not been described in detail so as not to
obscure the
implementations described herein.
100861 In this specification, elements may be described as "configured
to" perform one
or more functions or "configured for" such functions. In general, an element
that is
configured to perform or configured for performing a function is enabled to
perform the
function, or is suitable for performing the function, or is adapted to perform
the function,
or is operable to perform the function, or is otherwise capable of performing
the function.
100871 It is understood that for the purpose of this specification,
language of "at least
one of X, Y, and Z" and "one or more of X, Y and Z" may be construed as X
only, Y only,
Z only, or any combination of two or more items X, Y, and Z (e.g., XYZ, XY,
YZ, ZZ, and
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the like). Similar logic may be applied for two or more items in any
occurrence of "at least
one ..." and "one or more..." language.
100881 Unless defined otherwise, all technical and scientific terms used
herein have the
same meaning as commonly understood by one of ordinary skill in the art to
which this
invention belongs.
100891 Throughout the specification and claims, the following terms take
the meanings
explicitly associated herein, unless the context clearly dictates otherwise.
The phrase "in
one of the embodiments" or "in at least one of the various embodiments" as
used herein
does not necessarily refer to the same embodiment, though it may. Furthermore,
the phrase
.. "in another embodiment" or "in some embodiments" as used herein does not
necessarily
refer to a different embodiment, although it may. Thus, as described below,
various
embodiments may be readily combined, without departing from the scope or
spirit of the
innovations disclosed herein.
100901 In addition, as used herein, the term "or" is an inclusive "or"
operator, and is
equivalent to the term "and/or," unless the context clearly dictates
otherwise. The term
"based on" is not exclusive and allows for being based on additional factors
not described,
unless the context clearly dictates otherwise. In addition, throughout the
specification, the
meaning of "a," "an," and "the" include plural references. The meaning of "in"
includes
"in" and "on."
100911 As used in the specification and claims, the singular forms "a",
"an" and "the"
include plural references unless the context clearly dictates otherwise.
100921 The term "comprising" as used herein will be understood to mean
that the list
following is non-exhaustive and may or may not include any other additional
suitable
items, for example one or more further feature(s), component(s) and/or
element(s) as
appropriate.
100931 The devices, systems and methods described herein provide, in
accordance with
different embodiments, different examples of a health-monitoring sensor,
system and
method, such as a a non-invasive epidermal health-monitoring sensor, patch,
system and
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method In particular, some aspects of the herein described embodiments provide
a
relatively affordable and non-medical user-friendly device and/or system to
track health-
related variables in a non-medical context, for example, at home, in a
residence, in self-
isolation or under prescribed or recommended social distancing environments,
in large-
scale quarantine centers or the like.
100941 For instance, embodiments as described herein include an
integrated sensor that
can be operated from skin contact on or near the patient or user's head (e.g.
on the skin of
the forehead), or in other body skin locations amenable to suitable body
temperature and
spectroscopic probing, that can not only improve upon applicable manufacturing
and
commercial implementation costs and user friendliness, but also yield improved
health
monitoring accuracy and latency. For instance, an integrated spectroscopic and
body
temperature skin patch, or like form factor, may provide for a compact
solution to health
monitoring in concurrently, and from an integrated and non-invasive form
factor, monitor
critical health-related parameters such as, but not limited to, body
temperature (e.g. for the
onset, escalation, critical threshold and/or drop of a fever), standard
arterial blood oxygen
saturation levels (e.g. arterial oxygen saturation monitoring for risk of
hypoxia), enhanced
blood oxygen indicators (e.g. arterial and/or venous deoxyhemoglobin
concentration/
variations, oxygenated hemoglobin concentrations/ variations, derived
dissolved, stored or
discharged blood oxygen levels, hyperoxia risk monitoring, etc.),
spectroscopic cardiac
monitoring (e.g. heart rate, rhythm and/or pattern), spectroscopic respiratory
system
monitoring (e.g. respiratory rate, rhythm and/or pattern), blood pressure
derived from
spectroscopic readings (or obtained via a complementary sensor), etc.
100951 Furthermore, in some embodiments, a cerebral integrated
spectroscopic and
body temperature solution is provided that can enhance, as compared to other
skin patch
locations, measures for body temperature (e.g. as compared to a predominantly
arterial
neck patch solution, for example), and reduce detection latency, and/or
increase
detectability and/or accuracy for critical blood-oxygen-related health risks /
indicators. For
instance, a standard pulse oximeter will clip to a patient's finger and thus
capture less
reliable blood saturation data therefrom. However, if the patient is cold,
suffers from poor
blood circulation, has a low pulse, suffers from a respiratory condition
(which typically
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reduced blood circulation to extremities), or like conditions, standard pulse
oximetry data
acquired at body extremities may be of limited quality or lead to false or
delayed results.
For instance, in critical care context, the delay between gas exchange in the
lungs and
detection of changes in saturation at extremities has been shown to be
clinically significant
and reducing or eliminating this delay, for instance by operating a cerebral
spectroscopy
sensor as described herein, can result in improved patient outcomes.
100961 Conversely, the implementation of cerebral blood spectroscopy via
an
integrated head or forehead-mounted patch or like sensor, can result in
improved results as
it relates to reliability, accuracy and latency. Namely, while blood flow may
be reduced or
constrained from body extremities for various reasons, cerebral blood flow
will typically
take precedence in most physiological systems and medical contexts, thus
providing critical
information in a more reliable manner. Furthermore, as variations in cerebral
blood flow,
oxygen saturation, arterial and/or venous oxidized hemoglobin and/or
deoxyhemoglobin
concentration, dissolved oxygen variations or related metrics can represent or
expedite
detection of the onset of critical health conditions (e.g. cerebral hyperoxia,
hypoxia and/or
global respiratory conditions), the implementation of a cerebral health-
monitoring device
or system may provide enhanced health monitoring and alerting capabilities. A
forehead
patch also provides a convenient form factor in that it will typically not
interfere with
habitual user activities, and thus, may be less likely to be removed,
dislodged or tampered
with.
100971 As will be described in greater detail below, the integrated skin-
contact health-
monitoring device or system may be operable to communicatively link, for
example, an
integrated instrumented forehead skin patch with a wirelessly enabled mobile
or portable
device for local health tracking and/or data transmission to a remote health-
monitoring
server, database, center or clinic, for example. Accordingly, integrated
health-monitoring
data can be wirelessly, or less conveniently so, via wired connection, relayed
to a local or
remote user and/or monitoring interface for monitoring, historical tracking,
trend tracking,
population modelling and/or forecasting, medical intervention and/or planning
(e.g. at the
local, regional, provincial, state, federal, national, international and/or
global level),
alerting, and/or further processing. For example, while traditional health
monitoring
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devices may be configured to track a single or limited health-related
parameters, an
integrated health-related sensor and system as described herein may be
configured to not
only locally track health-related parameters locally for the given user (both
for respective
but also combined comparative health-related data monitoring / alerting), but
also leverage
historical average, time-variable, or community or group-based evolution
profiles of
respective, combined or comparative health-related data acquisitions so
provide greater
screening, testing, or diagnostic capabilities and/or result in more accurate
or predictively
effective treatments, therapies and/or accommodations.
100981 Furthermore, by combining vital sign monitoring as described
herein, with
communications and self-localization (e.g. GPS, cellular triangulation and/or
other self-
localization technologies, emergency contacts and/or services can be
automatically alerted
or contacted in the event of an emergency where the patient/user is otherwise
unable to
make direct contact (e.g. loss of consciousness, stroke, heart attack,
hypoxia, etc.). In that
respect, integration with self-localization technology, whether it be directly
implemented
within or in concert with the epidermal sensor, and/or cooperatively
implemented by a
mobile application implemented on the user/patient's mobile device using the
mobile
device's native GPS, cellular and/or Wi-Fi triangulation or like self-
localization
technology, can yield enhanced medical screening and tracking capabilities.
For example,
not only can a given patient gain access to cumulative knowledge and updates
for the
purposes of self-screening against dynamically optimizing medical baseline
profiles,
population mobility, interactions and symptom tracking and monitoring can be
implemented in real-time or near-real-time with high physiological data and
medical
screening accuracy, and high geographical localization and mobility accuracy.
As detailed
further below, such self-localization capabilities may thus provide for
greater oversight on
geographical infection rate or symptomatic distributions, migrations,
evolutions or
mapping, while also geographically mapping treatment effectiveness, recovery
or the like.
100991 Such integrated medical and geographic information, optionally
combined with
demographic or similar patient-related data, may provide particularly useful
in the context
of an outbreak, epidemic or pandemic, or again in monitoring progression of a
yearly
seasonal flu season, or the evolution and/or mutation and related symptoms or
manifested
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physiological response profiles over time and space of a new virus or illness
through
geographical mapping, contact tracking, etc.
1001001 As detailed further below, within the context of a respiratory
illness, such as
Covid-19, Severe Acute Respiratory Syndrome (SARS), Middle East Respiratory
Syndrome (MERS) or like viruses, which can lead to significant local,
regional, national
and/or worldwide infection, the acquisition and comparative analysis of data
from a large
group of individuals in respect of body temperature (fever), blood oxygenation
(e.g. blood
oxygen saturation, hemoglobin concentration variations, deoxyhemoglobin
concentration
variations, quantifiable dissolved or stored or metabolized oxygen
concentrations or related
values, etc.), cardiac activity/health (e.g. heart rate/pulse/pattern) and
respiratory activity
(respiratory rate/pattern) can result in greater monitoring, but also modeling
of the affected
group's response to the illness, impact on the group as the illness
progresses, improvements
or lack thereof in response to different treatments or therapies
(pharmaceuticals, herbals,
manipulative treatments, posture, life or respiratory support equipment such
as ventilators
.. or like oxygen-delivering devices, hyperbaric treatments, intubation, rest,
diet, fluid intake,
etc.), regional environment (e.g. ambient temperature, relative humidity,
etc.),
demographics (e.g. age, sex, ethnicity), medical history (e.g. pre-existing
conditions,
family history, etc.), behavioral characteristics (e.g. smoking or drinking
habits, working
environment, exposure to adverse substances, exercise habits, lifestyle, etc.)
or the like. For
.. instance, whereby a typical medical establishment could produce local
results on periodic
manual body temperature assessments and recorded blood oxygen saturation
results, a
more detailed and granular assessment can be provided both in combination from
a single
user-friendly and cost-effective form factor, but also in isolating, averaging
and comparing
time-variable profiles for respective (cerebral) arterial and/or venous
hemoglobin and/or
deoxyhemoglobin concentrations; stored, discharged, dissolved and/or
metabolized
oxygen content or concentrations derived therefrom; and/or comparative
tracking with
simultaneously acquired body temperature, heart-related and/or respiration-
related
parameters. Furthermore, as introduced above and further detailed below,
integration with
self-localization technologies may provide for automated emergency contact and
response
capabilities, as well as various epidemiological tracking / mapping
capabilities such as
infection rate tracking, geographical propagation, evolution and contact
tracking before
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and/or after the onset of defined symptoms and/or designated integrated
physiological
signal profile. For example, a triggered screening criteria or alert may
result from the
designated combination of one or more physiological criteria such as, but not
limited to, a
designated body temperature signature or threshold such as a detectable, mild
or severe
fever; a recognizable blood oxygen profile (e.g. designated oxidized
hemoglobin and/or
deoxyhemoglobin concentration variations or profile(s), derived dissolved or
metabolized
oxygen values or thresholds, blood saturation, etc.); a designated breathing
rate variation
and/or pattern; a designated heart-related pattern and/or profile; etc. This
alert may be
triggered locally through self-assessment against preset profiles loaded to
the user's mobile
device, or again triggered via remote assessment against a global storage or
database of
such baseline profiles. In either case, the alert may be logged and tracked,
along with a
geolocation of the user, for geographical mapping and tracking. Reverse and/or
forward
geographical tracking may also be applied to identifying geo-temporal overlaps
with other
tracked users so to identify potential infection risks and geographical spread
of a particular
condition or illness.
1001011 In accordance with some of the herein-described embodiments, the
epidermal
device and related system may be employed to monitor for abnormal blood
oxygenation
levels, amongst other parameters as noted above, of a user, for example at
home and/or
exposed to an oxygen-delivery apparatus in a medical or other context, thus in
some
examples exposing the user to partial oxygen pressures deviating from the
normal value of
0.21atm at Standard Temperature and Pressure (STP) or sea level. Namely, the
methods
and systems, according to different embodiments, may be used to monitor blood
oxygen
content (bounded to hemoglobin and/or dissolved in the blood or tissues) and
assess
accordingly a (escalated) health-related risk of hyperoxia, hypoxia,
respiratory illness,
contagion, etc. In some of the following examples, according to some
embodiments, the
user may be subject to utilizing an assistive breathing mask/apparatus, and/or
may be
located in a sealed and pressurized environment. This may include the user
breathing gas
that is either a hyperoxic or hypoxic mix (at any pressure) or normal air
(e.g. 21% 02) at a
higher or lower pressure than atmospheric pressure.
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1001021 In some embodiments, the systems and methods described below rely on
various oximetry techniques (e.g. pulse or cerebral oximetry, etc.) to
identify and quantify
the presence of one or more chromophores' molecules in the user's blood. The
measured
attenuation (or optical density) measured from one or more oximetry probes may
be used
.. to derive a corresponding oxygen partial pressure and/or relative oxygen
concentration in
said blood. This includes, in some embodiments, quantifying the concentration
of dissolved
02 (d02) by monitoring the oxygen input, levels of mixed blood saturation,
combined with
a physiological model of oxygen transport in the body. Thus, the systems and
methods
described herein, in accordance with some embodiments, may be used to monitor
in real-
time a user's health risk of hyperoxia, hypoxia and/or of a respiratory
illness, condition or
effectiveness.
1001031 In some embodiments, the oximetry technique used is based on near-
infrared
spectroscopy (NIRS). These are based on the fact that distinct biological
molecules change
their optical properties when binding to oxygen. This phenomenon is caused by
the fact
that chromophores such as oxygenated hemoglobin (oxyhemoglobin or 02Hb)
differs in
parts of its absorption pattern from de-oxygenated hemoglobin (deoxyhemoglobin
or
HHb), and thus in their apparent optical spectrum. These optical differences
can be
exploited using two or three (or more) distinct wavelengths in combination to
measure
arterial and/or venous hemoglobin/deoxyhemoglobin concentrations, arterial
oxygen
saturation, and derived dissolved oxygen values. Visible light penetrates
tissue only short
distances, since it is markedly attenuated by several tissue components, which
absorb or
scatter visible light. However, in the near-infrared (NIR) spectrum (ranging
from 700 to
1100 nm) photons are capable of deeper penetration of several centimeters or
more.
Moreover, NIR beams may also penetrate bones, which is prerequisite for trans-
cranial
cerebral oximetry for example, although generally speaking other probe
locations may be
used. Aside from the advantage of relatively deep penetration of several
centimeters, the
NIR spectral region is also characterized by typical differences in the
spectrum of
oxygenated and deoxygenated hemoglobin, for example. As mentioned above, other
chromophores present in the blood that may be monitored using these techniques
usually
comprise 02Hb and HHb, but other molecules may be monitored as well, for
example (and
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without limitation) cytochrome c oxidase, carbon monoxide (CO),
carboxyhemoglobin,
methemoglobin, etc.
1001041 In some embodiments, it may also be that one or more chromophores
being
monitored have more complex absorption spectra, such as a broader spectrum
and/or
comprising of two or more peaks. Generally speaking, the herein described
embodiments
are not limited to using one to three wavelengths, but may use as many
wavelengths as
needed to properly characterize the presence of one or more chromophore
molecules
present in the user's blood. To achieve this, any number of additional
wavelengths may be
used (e.g. any wavelength ranging from 600 to 1100 nm). Furthermore, measuring
such
components may result in overlapping spectra features for two or more
components. In this
case, multivariate statistical analysis methods may be applied to extract a
singular signature
for each overlapping component. For example, these may include, without
limitation: linear
(or non-linear) multivariate regression (MVR), principal component analysis
(PCA),
principal component regression (PCR), discriminant analysis (DA), hierarchical
cluster
analysis (HCA), soft independent modeling of class analogy (SIMCA), or
similar.
1001051 Exploiting these natural characteristics for regional oximetry such as
cerebral
oximetry (or other), a prototypical NIRS probe functions as follows: A light
source (e.g.,
one or more LEDs of different wavelengths) generates NIR light, concerning the
spectrum
centered around characteristic wavelengths. The emitted beam is directed into
the tissue of
interest via, in some embodiments, an epidermal probe (patch). The probe is
usually
attached to the skin above the tissue of interest (e.g. forehead or armpit for
optimal
concurrent body temperature measurements). Respective stickers of the probes
serve to
stabilize the probe's position over longer periods, but also restrict entrance
of ambient light
into the measurement photon pathway. Transcutaneous NIRS is noninvasive and
the
applied light intensities are not harmful to the tissue, not causing skin
burns even if applied
for a longer period.
1001061 Generally, the change in molar concentration of the monitored
chromophore
(for example 02Hb or HHb) may be calculated from the measured change
absorbance/attenuation of the NIRS signal by using a physical model of light
diffusion and
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attenuation in organic tissues derived from radiative transfer theory (e.g.
using a modified
Beers-Lambert law or similar; for example see: Susumu Suzuki, Sumio Takasaki,
Takeo
Ozaki, and Yukio Kobayashi "Tissue oxygenation monitor using NIR spatially
resolved
spectroscopy", Proc. SPIE 3597, Optical Tomography and Spectroscopy of Tissue
III, (15
.. July 1999); doi: 10.1117/12.356862 and Michael S. Patterson, B. Chance, and
B. C.
Wilson, "Time resolved reflectance and transmittance for the non-invasive
measurement
of tissue optical properties," Appl. Opt. 28, 2331-2336 (1989), the entire
contents of each
of which are hereby incorporated herein by reference).
1001071 Furthermore, in some embodiments, the molar concentration may then be
used
to assess, for example, the dissolved oxygen content in the user's blood
(d02). Indeed,
oxygen is found in two forms in the blood: in solution (or dissolved) and
bound to
hemoglobin. Since dissolved oxygen may accumulate in the blood and be
discharged at a
later time when partial oxygen pressures are lowered, such an assessment may
be important
for assessing a user's risk level. In some embodiments, a physiological model
may be used
.. to calculate the concentration of d02 (or change thereof). For example,
such a model may
determine, in some embodiments, the component or fraction of the inhaled
oxygen (e.g. as
breathed in directly or via an oxygen delivery apparatus) that is absorbed
into the blood
stream from measurement of the partial pressure of the inhaled gas mix since
the inhaled
and absorbed gases will reach equilibrium across the alveolar-blood interface.
Current
.. knowledge of physiological processes (such as Fick's diffusion law, 02
solubility, etc.)
allows for this evaluation. For example, assuming that the oxygen that enters
the blood
stream is either bounded to hemoglobin or remains in a dissolved state,
changes in the oxy
and deoxyhemoglobin concentrations in the target mixed blood volume can be
evaluated.
This in turn allows for a determination of the component that remains in the
dissolved state
under the assumption that other physiological parameters such as total
hemoglobin number,
blood volume, etc., remains nominal and constant. In some embodiments, such a
model
may use additional parameters such as the oxygen intake (e.g. quantity of
oxygen inhaled)
for example derived from a measurement of the flow rate of the inhaled gas
mix, ambient
pressure, an estimation or measurement of the user's blood volume, etc. In
some
embodiments, an index of user d02 levels may be constructed for reference.
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1001081 Other user body parameters may be used, for example and without
limitation,
parameters related to the user's weight/height, age and/or physical fitness.
1001091 In some embodiments, the monitoring systems and methods described
herein
may further be used to derive a cognition level or index of the user at
different levels of
blood oxygenation (bounded to hemoglobin and/or dissolved in blood or
tissues). The
cognition level may include characterizations of user fatigue, stress,
confusion,
engagement, workload and may be used to assess the ability of the user to
concentrate
and/or accomplish different tasks (e.g. efficiency and precision), such as
diving, piloting
an aircraft or spacecraft, etc. The systems and methods described herein, in
some
embodiments, may further display the user's cognition level in addition to
health-related
(escalated) risks of hyperoxia, hypoxia, respiratory illness and/or contagion.
The cognition
level may be derived, for example, by initially assessing the user's ability
to execute
specific tasks (i.e. speed of execution, number of errors, etc.) while
monitoring changes in
blood oxygen levels and deriving correlations from those measurements. In the
case where
the user's cognitive level is determined to be below a certain safety
threshold for
performing a specific task (i.e. flying an aircraft, etc.), the user may
decide or be forced to
stop and/or take a break.
1001101 With reference to Figure 1, and in accordance with one exemplary
embodiment,
an epidermal health-related sensor and monitoring system, generally referred
to using the
numeral 100, is shown. In the illustrated embodiment, the system 100 is
configured to
monitor for abnormal cerebral blood oxygenation levels, an increase or
variation in body
temperature (e.g. fever) and other health-related parameters illustratively
accessible via
epidermal cranial spectroscopy such as heart rate, pulse, blood pressure
and/or respiration
rate. In this exemplary embodiment, the patient is operating an oxygen
delivery or
breathing-assistance apparatus 102, such as a ventilator, etc., though other
oxygen-
providing devices or means may be considered, for example.
1001111 In this embodiment, the system 100 generally comprises at least one
integrated
epidermal patch 104, itself comprising a near-infrared spectroscopy (NIRS)
probe and
electric body temperature probe (neither explicitly shown), fixable through
epidermal
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adhesion in this example to the user's forehead for acquiring cerebral blood
oxygenation
data, body temperature data, and related data for downstream processing. As
mentioned
above, other embodiments may be configured to monitor different chromophore
molecules
present in the blood, such as deoxyhemoglobin and/or oxygenated haemoglobin
levels/concentrations, without limitation.
1001121 In some embodiments, the integrated patch 104 may be integrated inside
a type
of headwear, such as a headband or cap. In this case, the headwear should be
solidly affixed
on the head of the user to avoid suboptimal measurements due to a suboptimal
contact
between the various probes and the user's skin. As will be discussed below,
other
embodiments may use different skin contact locations, for example and without
limitation,
the neck region (e.g. through adhesion and/or a collar). In some embodiments,
the patch
104 will include a single-use or rechargeable battery or like power source so
to power
operation of the integrated sensors and communication means. In one such
embodiment,
the patch's power source may be rechargeable via a wired link, or again
wirelessly charged
by induction. In another embodiment, the patch may include a wired power port
continuously or periodically powered or recharged from the user's mobile
device. In yet
another embodiment, single use patches may be operated for a defined lifetime,
and
replaced thereafter with another patch.
1001131 From the absorption spectra measured from this patch 104, a relative
cerebral
(or regional) blood levels of these proteins may be calculated. To do so, the
at least one
patch is operatively connected to a digital data processor 106 programmed to
compute the
relative concentrations of both 02Hb and HHb, and/or a change in molar
concentration of
HHb or similar. In this embodiment, data is transferred through a wireless
connection, but
other embodiments, such as wired connections, may also be employed. As will be
explained in more detail below, the digital data processor 106 is further
programmed to use
these relative concentration measurements to derive or define, either locally
or through
communicative access to a remote monitoring/processing system, at least a
lower or higher
health risk rating.
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1001141 It will be appreciated that the processor 106 may take various forms,
which may
include, but is not limited to, a dedicated computing or digital processing
device,
microprocessor, a general computing device, tablet and/or smartphone
interface/
application, and/or other computing device as may be readily appreciated by
the skilled
.. artisan, that includes a digital interface to the patch 104 output so to
acquire and ultimately
process readings/spectra captured thereby. In the illustrated example, the
processor 106 is
provided by a user's portable device such as a smartphone communicatively
linked to the
patch via a wireless link, such as via BluetoothTM pairing, Wi-Fi, NFC or
other local short
or medium-range wireless communication protocols. While local processing may
be
.. implemented on the user's portable device 106, directly, in the illustrated
embodiment, a
further communicative link is made either directly (e.g. via cell data link)
or indirectly via
a local router 108 (e.g. local Wi-Fi or LAN), to a remote server and database
110, wherein
acquired data may be relayed thereto for processing, and/or to fuel global
data processing
efforts to track, update or optimize global treatment or illness data and
provide improved
assessment benchmark profiles (e.g. global averages, trends, recovery
patterns, illness
escalation patterns, etc.) so to concurrently improve global reporting but
also improve
treatment protocols and/or profiles, diagnostics, testing, screening or the
like.
1001151 Furthermore, the embodiment of Figure 1 further comprises a digital
user
interface, in this case provided via mobile device 106, capable of displaying
a health risk
.. indicator to the user in response to such data processing against benchmark
profiles. In
other embodiments, the digital user interface and digital data processor 106
may be
provided by distinct devices, for example, as will be readily appreciated by
the skilled
artisan, as can various health-risk-escalating alerting or reporting systems
be operatively
linked thereto for use by family members, caretakers, or the like. In some
embodiments,
such digital user interfaces may be comprised of a computer with a digital
display screen,
tablet, smartphone application or like general computing device, or again a
dedicated
device having a graphical or like general computing device.
1001161 In some embodiments, additional sensors may also be used in parallel
or
integrated with the epidermal patch 104. For example, pressure, temperature
sensors
(and/or one or more same and/or distinct physiological sensors or like
components operable
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to interface with the user (e.g. via a direct or indirect user contact, such
as a skin contact or
like interface operable in contact with or in close proximity to the user's
skin or body) may
also be used to acquire environmental and/or physiological signals and
operatively
connected to the digital data processor 106, either for direct transmission
consumption or
to be used as additional input in the determination of the user's higher or
lower health risk
rating. Examples of physiological signals that may be monitored via one or
more
physiological sensors include, without limitation, electrocardiograms (ECG),
electroencephalograms (EEG), breathing rate, V02, blood pressure, body
temperature, etc.
As will be discussed below, in some embodiments, one or more physiological
signal may
.. be correlated with the NIRS probe signal to provide a more precise
quantification of blood
oxygen levels, amongst other assessments.
1001171 In some embodiments, user body position may also be monitored with one
or
more accelerometers (not shown), as the user body position may affect the flow
of blood
to the head region (as will be explained below) and thus the spectral
response, and/or as
such position may impact escalation, assessment and/or treatment for a
particular
respiratory illness or condition. Therefore, in some embodiments, system 100
may further
comprise one or more accelerometers communicatively linked to digital data
processor 106
to detect changes in user body position or orientation (e.g. sitting vs.
supine, moving vs.
sedentary, etc.).
1001181 In some embodiments, system 100 may further comprise an internal
memory or
data storage module (not shown) communicatively linked to digital data
processor 106 to
store additional data which may be used to improve the monitoring capabilities
of system
100. For example, and without limitation, a local or remote (110) spectral
database
comprising information about the spectral signature of one or more known
chromophores
may be stored therein.
1001191 In some embodiments, digital data processor 106 and/or server-based
processing 110 may further be configured to provide additional features, such
as an
artificial-intelligence-based monitoring system. In some embodiments, the
system may be
configured to run an artificial intelligence (Al) program to provide user-
specific automated
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or semi-automated oxygen, temperature, respiratory, cardiac and/or related
symptom
monitoring, as will be explained below. For instance, Al can be integrated so
to
dynamically learn specifics for each given user and allow for downstream
personalization
of monitoring and alarm thresholds, for example.
1001201 Furthermore, digital data processor 106 may also, in some embodiments,
be
communicatively linked to the oxygen providing apparatus/device 102 so as to
regulate the
flow of gas to the user, depending on the user's blood oxygen levels being
monitored,
overall health condition, status of respiratory illness, perceived
effectiveness of current
oxygen delivery and/or treatment protocol, etc.
1001211 With reference to Figure 2 and in accordance with one exemplary
embodiment,
a method 200 for operating the system 100 of Figure 1 will now be described.
The user
first affixes (step 201) the integrated (cerebral NIRS / body temperature)
epidermal probe
to, for example, his/her head. The user/patient then optionally logs user data
(step 202) for
local or remote tracking purposes (name, demographic, medical history, medical
condition,
etc.).
1001221 The patch acquires data at step 204 to monitor for relative
variations, for
example, in oxyhemoglobin (02Hb) and/or deoxyhemoglobin (HHb) levels or
concentrations, body temperature, heart rate, respiratory rate, blood
pressure, etc. This data
acquisition is done continuously, in real-time or at short intervals. In the
presently
discussed embodiment, the acquired data is analyzed locally by monitoring for
relative
changes in 02Hb and HHb levels (step 206), amongst other data variations as
noted above.
These relative changes are automatically evaluated against present variations
corresponding to a plurality of benchmark health related profiles, such as
cerebral blood
oxygenation profiles, temperature thresholds or benchmarks, etc. (step 208).
These profiles
are preset and/or updated through a remote central server interface, as
described above. As
mentioned above, the profile may further comprise, in some embodiments, data
related to
one or more physiological signals, which would be acquired concurrently using
one or
more physiological sensors. Furthermore, as discussed before, the profile
themselves are
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associated with a preset health-related index that defines at least a lower
health risk rating
and a higher health risk rating (step 210).
1001231 As mentioned above, method 200 may also use at step 210 an artificial-
intelligence-based system to provide an improved monitoring capabilities of
the user's
oxygen levels and related risks. Such a system may receive and analyze in real-
time any
data being acquired via the patch, one or more physiological sensors, user-
body parameters,
total oxygen intake, manual changes in the oxygen content flow rates, etc.
Different AT,
machine learning and/or system automation techniques may be considered to
implement
such a program. For example, these may include, without limitation, supervised
and/or
unsupervised machine learning techniques, linear and/or non-linear regression,
decision
trees, etc. Deep learning algorithms may also be used, including but not
limited to, neural
networks such as recurrent neural networks, recursive neural networks, feed-
forward
neural networks, convolutional neural networks, deep-belief networks, multi-
layer
perceptrons, self-organizing maps, deep Boltzmann machines, and stacked de-
noising
auto-encoders or similar. As such, the intelligent monitoring features may
operate
autonomously or semi-autonomously, with limited or without explicit user
intervention.
1001241 Using hyperoxia as an example, if the method determines at step 212
that the
user is experiencing a lower risk of hyperoxia, nothing is done and the method
continues
the process of acquiring data of step 204. In contrast, if the method
determines that the user
is currently experiencing a higher health risk of hyperoxia, the method then
outputs the
higher health risk rating to the user (step 214) to inform him/her of the
higher risk so that
he/she may take action to reduce it. Risk or condition escalation may also be
used to locally
induce or recommend adjustment of a treatment or therapeutic protocol (222),
as the case
may be, so to dynamically monitor an impact thereof on the user's
condition/wellbeing.
Different examples of indicators may include, but are not limited to, visible
indicators such
as flashing and/or coloured lights, audible alerts (e.g. relayed through a
communicatively-
linked earpiece), vibratory device, or the like, which may take the form of
continuous,
blinking, pulsing, rhythmic, periodic and/or escalating alerts indicators. In
some
embodiments, visual indicators may be shown on a digital display or like
device.
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1001251 Then, as in the previous case, the method continues the process of
acquiring
data (step 204).
1001261 In this embodiment, optional tracking and feedback may be provided by
a
remote server system 230 operable to receive logged patient data 202, upload
acquired user
(raw, preprocessed or fully processed) health-related data or relative changes
therein for
global profiling and/or tracking (216), optionally use this data to update,
refine or optimize
benchmark profiles (218) can be relayed to / exchanged with the user's local
device/system,
and also serve to globally track health risks, conditions, improvements, etc.
(220) and
ultimately serve to update treatment/therapeutic protocols (222).
1001271 With reference now to Figure 17, and in accordance with another
embodiment,
a geographical or epidemiological health monitoring and tracking system,
generally
referred to using the numeral 1700, will now be described. As will be
appreciated by the
skilled artisan, a geographical system should be understood to be deployable
across a
variety of geographical areas, such as, but not limited to, a municipal,
regional, county-
wide, provincial, state-wide, national or international area, or even
globally, with option to
subdivide tracking, monitoring and reporting capabilities according to
different underlying
areas ranging from neighborhoods and communities, to nations and beyond.
1001281 In the illustrated embodiment of Figure 17, the system 1700
relies, at least in
part, on vital or symptomatic data acquired or otherwise captured by one or
more health
related sensors disposed so to actively track a health-related condition of
its various
participants, wherein such participants may include, but are not limited to,
volunteers,
patients or participants in one or more schools, workplaces, hospitals, health
care of
institutional settings, or again volunteers or mandated individuals in one or
more prescribed
communities, areas, etc. For descriptive purposes, the system 1700 in Figure
17 is
illustrated to interface with epidermal sensors 1704 much as those (104)
described above
within the context of Figure 1, for users with or without support from an
oxygen-delivering
apparatus. In some embodiments, however, the system 1700 may be further or
alternatively
configured to operate with other dedicated and/or common network-enabled
health-related
sensors, such as, but not limited to, medical grade or institutional
oximeters, cardiac
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monitors, thermometers or the like, or again, common or dedicated wearable
sensors such
as those previously operated within the context of a smartwatch, fitness
tracker (e.g.
integrating various health-related monitors in concert with integrated GPS
and/or
Bluetooth TM pairing capabilities). In some embodiments, the system may
interface with
different types of sensors, or require deployment of dedicated sensors for the
purpose of
data integrity, reliability, and/or user privacy considerations.
1001291 Within the context of Figure 17, a sensor 1704 worn or otherwise
linked to a
first infected user "A" can report, or result in the remote identification of
a set of designated
health-related parameters corresponding with a designated condition or
illness, which
result is monitored and tracked by global server system 1710. Given self or
remote-
localization capabilities, the first infected user "A" can be geographically
identified in area
1740. Over time, other infected users "B" may be identified in geographic area
1740
suggesting a local spread of the condition or illness in that area, and
encouraging further
regional measures to contain this spread as it continues to spread to users
"C", "D" and "E"
over time in this region. Using this system and various medical, geographical
and/or
mobility modeling techniques, this infection spread can be linked and traced
back to user
"A" with reasonable accuracy, particularly where similar symptoms and/or
medical health-
related sensor data patterns or profiles match to a significant degree. Other
parameters such
as demographics, medical history, etc. may also be considered. Furthermore, by
relying on
comprehensive medical data analysis, one may observe an invention spread
geographically
despite some intervening users not exhibiting otherwise readily perceptible
symptoms (e.g.
an asymptomatic user may still cary the illness and manifest certain health-
related
signatures observable by the system).
1001301 In the illustrated embodiment, the spread of the infection to other
areas, such as
region 1750, can also ultimately be observed and traced back to a user in
region 1740 upon
recognizing that an isolated infection in region 1750 likely resulted in that
user having
recently interfaced with a user "C" in region 1740 (e.g. should a location of
a user from
region 1740 have previously overlapped within a designated timeframe (e.g.
carrier or
incubation window) with a similar location from the infected user of region
1750. This can
thus not only identify infection spread, but also potentially identify
infection routes and/or
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causes, which can be used to revise or improve infection containment measures.
As noted
above, variations and/or evolutions of reported or measured symptoms or vital
signs may
also educate the system on an evolution or mutation of the illness, and
approaches to
treating it (e.g. observing greater treatment effectiveness or rehabilitation
in some areas
over others).
1001311 Yet in the same example, another isolated event "X" in region 1760 can
be
further investigated should there be no geographical overlap with other
current or
previously infected users, suggesting other means of transmission and reason
for further
external investigation.
1001321 Accordingly, using reliable health-monitoring sensors and designated
multivariate health risk profiles, in combination with geolocational tracking
and reporting
capabilities, greater epidemiological data can be captured, shared, and acted
upon to reduce
the spread of an infection, expedite treatment and/or isolation of infected
parties, and/or
evaluate containment or treatment strategies.
1001331 The person of ordinary skill in the art that the above examples may be
implemented using different techniques, equipment, and protocols, and that all
such
variants should be considered to fall within the general scope and nature of
the present
disclosure.
1001341 Likewise, the above-described embodiments may be applied to different
contexts or applications, such that, for example, user health-related tracking
and monitoring
(e.g. monitoring for illness, heat stroke, dehydration, fatigue, etc.) may be
applied in an
open or enclosed space, for example, in or across multiple (large scale)
industrial or
manufacturing settings, office towers, hospitals, retirement residences, long
haul cruise or
cargo ships, mining centers, amusement parks, shopping malls, farms or like
institutional,
recreational and/or workplace environments. These and other such examples
should be
considered to fill within the general context of the present disclosure.
1001351 The following provides various other details/examples applicable
within these
contexts.
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1001361 As noted above, some of the methods and systems described herein make
use
of vital sign monitoring devices, optionally using non-contact (at-a-distance)
and/or contact
(wearable) platforms, for users optionally using or subject to using self-
contained oxygen
delivery systems or oxygen supply systems used in treatments such as in
hyperbaric therapy
and supplemental oxygen therapy. Enhanced blood oxygenation monitoring
capabilities
for tracking risks of hypoxia and/or hyperoxia are also considered, in some
embodiments,
with further tracking capabilities to identify both abnormally high and low
levels of oxygen
and detect when a user has reached hazardous levels. In one embodiment,
spatially-
resolved spectrometry can be used to derive absolute tissue saturation in
addition to pulse
and respiration rates. Inertial Measurement Units (IMU) can also be used to
account for
motion of the subject being monitored.
1001371 To leverage the benefit of access to large amounts of continuous data,
in some
embodiments, the device and system is also enabled with an Artificial
Intelligence (Al)
capability which enhances its performance at identifying specific conditions
of concern,
and allowing it to be personalized for each user's physiology.
1001381 While specialized use in considered in some embodiments, other
embodiments
may be adapted to vital sign monitoring for a wider general population. For
example, as
detailed above, single detector oximetry (as opposed to spatially-resolved
spectrometry)
can likewise integrate complementary vital sign sensors and at the same
benefit from access
to Big Data.
1001391 One exemplary sensor design comprises several subsystems, each
handling a
core function including data acquisition, data storage and processing, power
supply,
communication, inertial measurement (IMU), and positioning.
1001401 In this example, the data acquisition subsystem is in contact with the
skin. It
carries the LEDs and detectors. The design uses a medical-grade adhesive foam
to keep the
device attached to the skin while blocking out ambient light. This adhesive
layer is
disposable. The rest of the module is sealed and can be disinfected.
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1001411 The data processing subsystem currently works in two modes. The
offline mode
is used when measurements need to be stored for post-processing because no
stable real-
time communication is possible, such as when the subject is underwater or out-
of-range to
a receiving station. The offline mode can also be used in medical situations
where the
.. patients is mobile and requires monitoring without continuous access to the
data acquired
by the device. When communication is possible, the module can be run in an
online mode
with live data transmission to a base station (e.g. mobile device, router,
watch, or the like)
for real-time processing and monitoring. In either mode, the module is
programmed to
trigger an alarm when conditions pre-defined as hazardous are detected.
1001421 The power subsystem carries the rechargeable battery and is integrated
with the
rest of the device to allow for a one-piece compact device. In the current
prototype, the
option exists to have power relayed to the sensors through a wired connection
to allow for
prolonged runtime with larger batteries packs.
1001431 The communication subsystem is currently designed with Bluetooth BLE
connectivity. From our testing to date, we have shown that the BLE protocol is
sufficient
for the required data transfer and allows the maximization of power
efficiency. Bluetooth
allows for a broad range of compatibility with COTS tablet interfaces and
network
computers.
1001441 The IMU subsystem can be used to track motion of the subject. The data
can be
used to compensate for motion as well as to detect the patient's orientation
that can be a
factor when calculating blood flow and volume, for example.
1001451 The positioning subsystem uses high-accuracy ultra-wideband (UWB)
positioning technology. The positioning using this approach uses a dedicated
module that
communicates with base stations. Positioning through GPS, either via an
integrated GPS
receiver or via an integrated GPS of a paired mobile device, can otherwise be
used, as noted
above. UWB nonetheless provides some advantages over GPS in some environments,
such
as indoors, where a very significant portion of medical applications are
expected to be. Yet,
depending on the granularity of the localization data required, different
levels of self-
localization technology may be considered.
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1001461 In one embodiment, the device is capable of measuring oxygen
saturation levels
and pulse rates and respiration rates; it comprises integrated, or interfaces
with
complementary accelerometers to track and report motion; and it is compatible
with
positioning systems. In one such embodiment, the device is Bluetooth-enabled
and
designed to communicate directly with either a COTS tablet or PC.
1001471 As noted above, the device can be designed with an integrated BLE chip
to
connect to mobile devices and PCs that will act as base stations for
command/control and
data exchange.
1001481 In some embodiments, the device is designed to be waterproof (to
technical
diving depths) and can withstand extreme environments with high and low
atmospheric
pressures, should it be necessary.
1001491 It is also designed with a built-in clock for timestamping data and
synchronisation, and current power specifications are set at roughly 48 hours.
1001501 In some embodiments, as noted above, different powering techniques may
be
considered. In one example, an integrated battery is provided in the main
housing of the
device to reduce size and increase wearability and versatility. In another
example, an
independent battery housing can be connected by wire to the main module for
increased
autonomous operational time. Power consumption will depend greatly on the
frequency of
data acquisition, transmission, processing, etc. The current design calls for
autonomous
operations for at least 48 hours in nominal mode. This can be adjusted to meet
the needs of
a particular application.
1001511 In some embodiments, the device is small and meant to be worn while
conducting arduous tasks (underwater, military piloting, firefighting, etc.),
and is therefore
suited for wearing when exercising and sleeping.
1001521 Other aspects of different embodiments include different placement
options,
such as the forehead in one example to target oxygen levels in the cerebral
region, or on
the neck to target measurements in the carotid artery. Other body locations
can also be
considered.
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1001531 As noted above, either of spatially-resolved spectrometry or single-
detector
oximetry can be considered, as can other options. Spatially-resolved
spectrometry
generally involves multiple detectors at defined distances from a light
source. The
increased number and type of sensors, increased processing and data
requirements, as well
as power requirements represent an increased cost. However, this in turn
offers unique
functionality that can make the device optimal for versatility in operation
and richness of
the data acquired. A variant with one light source and one detector can
otherwise be used,
for example, for transmission or reflectance measurements, the latter
significantly
improving the flexibility of positioning of the device as it could be anywhere
on the body
whereas transmission-type sensors are typically limited to the fingers, toes,
or ears (with
drawbacks as a noted above).
1001541 As described above, a miniaturized temperature sensor specifically
designed for
body temperature measurements can be used in concert with oximetry and/or
other sensors.
1001551 Blood pressure can also be measured through photoplethysmography or
other
sensor techniques. The noted technique generally relies on recognizing
similarities between
arterial blood pressure (ABP) and photoplethysmography (PPG) signals, noting
that PPG
signals contain much of the information that is used to derive blood pressure
from
conventional ABP signals.
1001561 As further noted above, some embodiments may be configured to
implement an
AI-enabled predictive algorithm and a geospatial-vital sign trending feature.
Both features
are possible given the unique capability to acquire Big Data with this device.
For example,
large-scale vital sign monitoring data can be acquired with continued use of
the device.
This data can be used to assess trends in data variability and train each
device with a
predictive ability. This feature will also allow a comparative analysis of the
trend observed
for one individual in relation to the population-based datasets.
1001571 The opportunity to have a widely distributed vital sign monitor that
can be
positioned offers the unique opportunity to capture epidemiological data on a
real-time
scale that has not been previously possible and can be especially useful in
pandemic
scenarios to study disease spread. Geospatial trends can be analyzed without
the need to
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mobilize large populations to enter data, without risking false or erroneous
data, while
ensuring data anonymity.
1001581 The following explains, in part, how cerebral blood oxygenation
profiles may
be determined, in accordance with one embodiment, to go beyond standard blood
oxygen
saturation results and thus, provide for greater granularity and flexibility
in evaluating a
patient's oxygen intake, metabolism, overall respiratory and/or circulatory
health, and/or
related conditions, health factors or illnesses. The person of ordinary skill
in the art will
readily appreciate that while such examples are provided, different
embodiments of the
herein-described health-related sensors, monitors, systems and global
monitoring, self-
learning, and/or tracking systems may also or alternatively rely on other
health-related
patterns, such as, but not limited to, those presented and described above in
various details.
1001591 With reference to Figure 3, and in accordance with one exemplary
embodiment,
a plot is provided of the relative change in cerebral deoxyhemoglobin (HHb)
absorbance
(e.g. optical density), as a function of time, of an individual breathing a
series of gas
mixtures with a reduced oxygen concentration (hypoxic mixes). The measurements
were
taken using a commercially available NIRS system developed by Artinis Medical
Systems
B.V. The absorbance values are relative to the baseline values obtained with
the same
individual breathing normal air (21% 02) and three runs were measured with
hypoxic
mixes of 5%, 9% and 13% oxygen respectively. For each data series, the
individual
sustained breathing the associated mix as long as comfortable, then returned
to breathing
normal air again. Clearly, breathing lower levels of oxygen, as is well known,
leads to a
rapid increase in HHb levels. The lower the oxygen level, the faster and
higher the rise in
measured HHb levels is observed and the shorter the time the individual could
sustain
respiration.
1001601 In contrast to Figure 3, Figure 4 is a plot, as a function of time, of
the change of
HHb levels while breathing an increased concentration of 02 (hyperoxic mix).
Three
measurements are shown, one baseline measurement at a normal 02 concentration
of 21%
(e.g. normal air) (dark gray dotted line), one measurement done with a mix
containing 31%
02 (light gray dotted line) and one measurement with pure 02 (black line). In
the last two
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measurement series, the individual was breathing normal air in the first and
last 5 minutes
of the experiment. We clearly see the reduction in HHb concentration measured
with the
increased intake in 02. Moreover, while the measurements at 31% 02 show a
quick return
to the baseline value after the individual stopped breathing the gas mixture,
in the second
case, while the HHb concentration increases and stabilizes after the pure 02
is removed, it
never quite returns to baseline during the acquisition time, though will
clearly eventually
return to baseline over time. These measures thus illustrate the tissue's
ability to store
oxygen, which may become increasingly important for greater oxygen partial
pressures.
Using methods as described herein, in some embodiments, means may thus be
provided to
monitor the discharge of oxygen from tissues into the blood.
1001611 Figure 5 shows the effect, as a function of time, of both changing an
individual's
position (sitting or supine) and breathing pure oxygen (100% 02) vs. normal
air (21% 02).
Both the relative absorbance values of the oxyhemoglobin (02Hb) and HHb are
shown.
For this experiment, the individual is initially breathing normal air (21% 02)
in a sitting
position for 5 minutes, followed by being put in a supine position for another
5 minutes.
The individual, still in a supine position, was then exposed to a pure oxygen
gas via a face
mask for a number of minutes. Without changing the individual's position, the
mask was
then removed, allowing the individual to breath normal air again. Finally,
after waiting a
few minutes, the individual was allowed to sit again. We clearly see the
effects these
changes have on both the 02Hb and HHb measurements. However, we find that the
02Hb
and HHb responses are not symmetrical, indicating that measurement only the
02Hb
concentration may be unreliable as the only indicator of cerebral blood
oxygenation in all
contexts. However, a careful measurement of both 02Hb and HHb concentrations
using
NIRS does lead to the determination of a more precise index.
1001621 Figures 3 to 5 clearly show characteristic signatures of the changes
in 02Hb
and HHb levels not only as a function of oxygen content breathed by an
individual but also
as a function of the individual's relative position. By measuring the changes
in 02Hb and
HHb levels for a series of different oxygen levels in different individuals, a
series of
benchmark cerebral blood oxygenation profiles may be recorded. These profiles
may then
be digitally associated with a preset cerebral blood oxygenation index that
may then be
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used to associate a lower or higher risk rating of hyperoxia in the
individual, of example.
The benchmark profiles may be expanded to include different partial oxygen
pressures by
doing measurements inside a hyperbaric or isobaric chamber, for example.
1001631 With reference to Figure 10 and in accordance with one exemplary
embodiment, another method for monitoring a user's health risk when partaking
in an
activity requiring the use of an oxygen providing apparatus and/or inside a
sealed
pressurized environment, generally referred to using the numeral 1000, will
now be
described. Similar to the embodiment described in Figure 2, at step 1001 one
or more
sensors are affixed or put in contact with the user's skin at one or more
locations. These
sensors may be integrated into a wearable device as explained above. Once the
user begins
the activity at step 1002, method 1000 immediately starts monitoring one or
more
parameters. At step 1003, the method monitors via one or more NIRS probes the
molar
concentration of HHb in the user's blood (for example in the cerebral region),
but may also
optionally monitor in parallel other parameters such as ambient pressure
and/or
temperature (step 1004), oxygen intake (step 1005), one or more physiological
signals via
one or more physiological sensors (step 1006) and/or user body position via
one or more
accelerometers (step 1007). Data acquired from steps 1003 to 1007 is sent to a
central
processing unit (i.e. digital processing unit 106 for example) to be analyzed
and compared
to preset benchmark profiles at step 1008. As discussed above, in some
embodiments, step
1008 may be performed using machine-learning techniques such as deep learning
techniques or similar. From this analysis, a health-related risk of
hyperoxia/hypoxia and
optionally a user cognition level may be defined at step 1010. At step 1012,
these risk
and/or cognition levels may be compared to previous levels to determine if an
increase in
risk or a loss of cognition has occurred. In this case, method 1000 may
automatically adjust
the flow of oxygen delivered to the user to reduce the risk and/or increase
the cognition
level. Optionally, at step 1014 a warning may also be delivered to the user as
explained
above. The method then goes back to monitoring different parameters (steps
1003 to step
1007) to assess a new risk and/or cognition level.
1001641 With reference to Figures 6 to 9, and in accordance with one exemplary
embodiment, different plots are provided of the change in cerebral HHb
concentration (in
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M or 10-6 mol/L), as a function of time, of an individual subjected to
different oxygen
partial pressures. These figures clearly show the different correlations
between the
measured molar concentration of HHg different parameters, including partial
oxygen
pressure but also sustained physical activity. The measurements were again
taken using a
commercially available NIRS system developed by Artinis Medical Systems B. V.
Changes in molar cerebral HHb concentrations were calculated from changes the
NIRS
attenuation signal using the light diffusion model of Suzuki et al. mentioned
above. Thus,
in Figures 6 to 9, only changes in the measured cerebral HHg concentration
with respect to
the initial value are meaningful and the initial concentration value at the
start of each Figure
is arbitrary.
1001651 For example, Figure 6 shows a plot of an individual being completely
immersed
in water at different depths and breathing sequentially from two different gas
mixtures
(normal air and Nitrox 40 hyperoxic mix). At the start of the plot shown in
Figure 6, the
individual is breathing the Nitrox 40 mix while floating at the surface (e.g.
p02 = 0.4). As
the depth increases, we clearly see the concentration of cerebral HHb
decreasing as well
with respect to the initial value (at the surface at t = 2000 sec.) by about 7
M until a depth
of 57 feet is reached with a corresponding partial oxygen pressure of 1.1. The
diver stayed
at that depth for about 10 minutes before resurfacing at around 2400 sec.,
where we see the
concentration of HHb increasing correspondingly by about 2.5 M, returning it
close to its
initial value at the start of the experiment. Thus Figure 6 shows a clear
correlation between
changes in oxygen partial pressure and corresponding changes in cerebral HHb
concentration.
1001661 Similarly, Figure 7 shows a plot of the change in cerebral HHb
concentration
as a function of time but for an individual inside a sealed hyperbaric chamber
where both
a change of 02 concentration was administered and a change in depth simulated
by varying
the pressure. Thus, the partial oxygen pressure inside the user could be
changed by either
changing the pressure in the chamber or by changing the oxygen concentration
the
individual was breathing (air or hyperoxic mix). Starting from a normal oxygen
partial
pressure of 0.21 (e.g. breathing normal air at atmospheric pressure), the
pressure inside the
chamber was increased to simulate a corresponding depth of 30 feet (p02 =
0.40) which
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led to a small decrease in cerebral HHb concentration (with respect to its
initial value at t
= 400 sec.) of about 0.8 M. Then, at around 900 seconds, the pressure was
kept constant
but the breathing mix was changed from air to pure oxygen (p02 = 1.9). We
quickly see
the HHb concentration further decreasing by a value of about 2 M. The next
step consisted
of letting the individual breathe pure oxygen but to decrease the pressure to
simulate a
depth of 15 feet (p02 = 1.45). We see that this leads to a corresponding
increase of the
HHb concentration by about 0.8 M. Then, keeping the pressure constant, the
individual
was given normal air to breathe (p.02 = 0.3). We again find a corresponding
rapid increase
in the concentration of cerebral HHb by a value of 1 M. Finally, the normal
atmospheric
pressure was restored which led the concentration to return to its initial
value (at t = 0).
Thus, we clearly see in Figure 7 the correlation between changes in depth and
partial
oxygen pressure and the corresponding variations in the cerebral HHb
concentrations.
1001671 Figure 8 illustrates, similarly to Figure 5, the effect, as a
function of time, of
both changing an individual's position (sitting or supine) and breathing pure
oxygen (100%
02) vs. normal air (21% 02), again inside a hyperbaric chamber. In the plot of
Figure 8,
the individual is first in a seated position while breathing normal air. The
pressure was then
increased to a corresponding depth of 30 feet, resulting in a corresponding
decrease in the
HHg concentration by about 2 M with respect to its initial value (t = 2000
sec.). Then, the
individual, still seated, was administered pure oxygen (p02 = 1.9) which leads
to another
decrease of the HHg concentration by about 0.6 M. Next, keeping the pressure
constant
(30 feet) and still breathing pure oxygen, the individual was asked to take to
a supine
position, which causes the measured concentration of cerebral HHb to decrease
further by
about 2 M. Going back to a seated position cancelled, as expected, the
previous variation
by increasing the HHg concentration by 2 M. Now changing the breathing mix
from pure
oxygen to normal air (but keeping the pressure constant and a seated position)
also returned
the cerebral HHg concentration to a value of about 1.9 M below the initial
value. Finally,
decreasing the pressure to normal atmospheric pressure returned the measured
HHg
concentration close to the initial value at the start of the experiment. Thus,
we see that the
derived molar concentration also correlates well with the user body position.
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1001681 As mentioned above, in some embodiments, one or more physiological
signals
may be acquired concurrently with the NIRS signal to provide an increased
accuracy in the
calculated blood oxygen content, for example by using measured correlations
between the
changes in these one or more physiological signals and the HHb concentration
levels (or
other chromophores) when the user is engaging in a physical activity. For
example, in
Figure 9 we see three plots illustrating the corresponding change over time of
the
concentration of cerebral HHb, the user's heart rate (in beat per minute or
BPM) and the
breathing or respiration rate (in breaths per minute), from top to bottom
respectively, of a
user engaging in an underwater physical activity as a function of time. In
Figure 9, the
individual is initially breathing an hyperoxic mix (p02 = 0.4) while at rest
at the surface
and then descends underwater to a depth of 57 feet (p02 = 1.1), leading to a
corresponding
decrease in the measured cerebral HHb concentration of about 5 M below the
initial value
(t = 1055 sec.). This decrease is also correlated with a small decrease in the
heart rate from
120 BPM to about 95 BPM. The individual then started engaging in a physical
activity for
more than 10 minutes, which immediately results in an increase in the measured
heart rate
(from 95 BPM to about 128 BPM with peak at 140) and the respiration rate (from
about 10
breaths per minutes to around 19-20 breaths per minute), and a corresponding
decrease of
the HHb concentration by about 4 M (e.g. 10 M below the initial value). This
decrease
in the HHg concentration is directly linked to the physiological processes
caused by the
physical activity being performed and not linked to the partial oxygen
pressure alone, as
will be seen below. Following this, the individual returns to the surface
while still breathing
the hyperoxic mix, which shows as a slight increase in the HHb concentration
by a value
of about 4 M. Finally, the diver resumes breathing normal air, which shows up
again as
an increase in the HHb concentration of about 4 M. Thus, the measured
cerebral HHg
concentration at the end is still 4 M below the initial value at the start of
the experiment,
which roughly corresponds to the decrease observed when the user was engaged
in the
physical activity, as expected.
1001691 As noted above, conventional oximetry relies on measurement ratios for
2
blood-oxygen-related absorption wavelengths (oxyhemoglobin and
deoxyhemoglobin) to
produce useable, but limited results. Indeed, absorption ratios lose
specificity in observing
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actual or absolute blood oxygen concentrations and neglect the finer detail
otherwise
available using techniques as described herein that probe and analyze greater
portions of
the blood or probe tissue's absorption spectrum. Moreover, since it relies on
indices that
are derived principally as ratios and are relative to baseline measurements,
conventional
oximetry also requires calibration (or the use of look-up tables) to associate
a measured
index with a saturation level, further restricting use and applicability.
Furthermore,
conventional pulse oximeters often do not provide reliable readings when
saturation is low,
and require that a pulse or heart beat be continuously and accurately
detectable. While
spatially-resolved spectrometry can provide further information as it invokes
a spatial
investigation, it remains constrained to the analysis of relative spatially-
resolved
concentration ratios, and thus remains unable to extract absolute total
concentrations.
1001701 In some of the herein-described embodiments, oximetry data can be
acquired
using a spectroximetry probe, such as that described in greater detail below.
For example,
the systems and methods described herein provide, in accordance with different
embodiments, different examples of a system and method for monitoring or
assessing one
or more physiological or health-related parameters or condition(s) in a user
or patient via
full or broad-spectrum oximetry, which is herein interchangeably referred to
as
spectroximetry or hyperspectral oximetry. Using a spectroximetry probe as
described
below can, in some embodiments, further enhance implementation of a
physiological
monitoring system, as described above, though other oximetry probes may also
be
considered in that context. Meanwhile, a spectroximetry probe and system as
described
herein may provide other benefits in other contexts, as detailed below,
without limitation.
1001711 In contrast with standard oximetry, full or broad spectrum oximetry
(sepctroximetry or hyperspectral oximetry), as provided by the exemplary
systems and
methods described below, in accordance with different embodiments, has the
unique
feature of allowing the measurement of the entire absorption spectrum of
interest, such as
for example between 600 nm and 1000 nm. Namely, a broad range of probing
wavelengths
can be leveraged, in different embodiments, to extract a coarse or even fine
resolution
absorption spectrum that carries a greater wealth of information for the
purposes of
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conducing and outputting a more detailed analysis and evaluation of the probed
tissue's
oxygenation profile, status or condition.
1001721 For instance, in some embodiments, spectroximetry has the advantage of
measuring absolute energetic transmission over a broad range of wavelength.
This absolute
measurement can allow for the comparison of absorption profile variations for
the same
patient at different times, and between patients, for example. Current
oximetry
methodologies rely on indices that do not lend to such analysis.
1001731 With reference to Figure 11, and in accordance with one exemplary
embodiment, a full spectrum oximetry system, interchangeably referred to as a
spectroximetry system, and generally referred to using the numeral 1100, will
now be
described.
1001741 Pulse oximetry is often used in health-related systems to monitor
blood
oxygenation. This typically works by emitting NIR light into tissues,
measuring the
corresponding transmitted or reflected light at two distinct wavelengths, and
deriving from
changes in absorbance a corresponding change in oxyhemoglobin, for instance,
in the form
of an estimate from relative variations, calibration or via index-tables. In
this exemplary
embodiment, however, system 1100 comprises a broad-spectrum probe 1102, which
may
be attached to the skin above the tissue of interest or as illustrated herein
integrated into or
inside a type of cerebral patch or headwear (here headband 1104). Probe 1102
generally
comprises at least one broad-spectrum infrared light source 1106, for example
one or more
LEDs may be used alone or in combination to generate IR light covering a broad
range of
the infrared spectrum (e.g. for example wavelengths between 600 nm to 1000
nm). Light
source 1106 is generally configured so as to emit light into the tissue of
interest, this
example the head/brain region. It some embodiments, it may comprise one or
more LEDs
manufacture into a single device, or in other embodiments multiple LEDs may be
used at
different physical locations. Naturally, while a broad IR range of 600 nm to
1000 nm is
presented here as an example, it will be appreciated upon further reading that
different
shorter or longer ranges can be considered without departing from the general
scope and
nature of the present disclosure. It will also be appreciated that different
light sources
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and/or combinations of light sources 1106 may be considered to provide such
range, to
accommodate different probing spectrum intensity or continuity profiles, or
the like,
without departing from the general scope and nature of the present disclosure.
Furthermore,
while focus is made on a broad spectrum IR light source, other complementary
spectral
regions may also be considered where absorption, transmission and/or
reflectance spectra
can provide complementary information or characteristics on blood-oxygen or
other blood-
constituent elements of interest.
1001751 In this embodiment, probe 1102 further comprises at least one high-
resolution
miniature spectrometer or sensor 1108 to record one or more high-resolution
absorption or
transmission spectra of the transmitted or reflected light from light source
1106. Miniature
spectrometer 1108 may take different forms and/or have different
specifications. In
general, spectrometer 1108 should have a high spectral resolution sufficient
to confidently
reproduce a representative spectral signature received by probe 1102 over the
broadband
infrared range of interest. In some embodiments, spectrometer 1108 may be
based on a
diffraction grating design, a multi-layer filter design, a combination thereof
or another
design entirely. For example, and without limitation, spectrometer 1108 may be
operable
to acquire spectral data with a 5 nm resolution over the whole range between
600 nm to
1000 nm (e.g. 10, 40 or even 80 distinct wavelengths/spectral regions). The
skilled
technician will understand that different numbers of wavelengths with
different resolutions
may be considered. In general, the acquired spectral data should have a
resolution that
allows to differentiate between different peaks or dips of interests, with
sufficient details
so as to allow for comparative analysis of such acquired spectra with
designated
representative spectra or spectral variations therein, and or with previously
or continuously
acquired spectra as a user's condition and/or environment changes. Namely, as
will be
detailed below, acquired spectra may be used for comparative analysis as a
single
diagnostic or screening tool against preset or designated standard spectra
representative of
healthy, low risk or high risk conditions, illnesses, and/or environmental
scenarios, or again
as continuous or regular monitoring means whereby observed spectral profile
variations in
different spectral regions or combinations of such regions can be
quantitatively or
.. qualitative mapped to corresponding conditions or risk factors.
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1001761 With continued reference to Figure 11, different configurations of
light source
106 and spectrometer 1108 may be considered for probe 1102. In some
embodiments, a
single light source 1106 and spectrometer 1108 may be used. For example, a
single broad
IR spectrum LED and a single sensor may be used, with a pre-defined distance
therebetween. In some embodiments, sensor 1108 and the single LED of light
source 1106
may be placed opposite each other (e.g. with the tissue of interest in-
between) so as to
measure the transmission (or absorption) spectra. In other embodiments, a
linear
configuration may be used where the LED of light source 1106 and sensor 1108
are placed
next to each other (as shown in Figure 11), pointing in the same direction, in
order to
measure the light scattered back from the tissue volume they are placed on.
1001771 In yet another embodiment, one sensor/spectrometer 1108 may be placed
linearly alongside a light source 1106 comprising multiple LEDs (reflection-
type design).
In this configuration it may be possible to have different pre-defined
distances between
each LED and sensor 1108. The difference in distances may thus allow for
spatially-
resolved data to be acquired.
1001781 In yet another embodiment, probe 1102 may consist of a light source
106
comprising a single LED, but with sensor 1108 comprising several individual
sensors
instead of a single device, e.g. laid out in a linear spatially-resolved
reflection-type
configuration. This layout thus also allows spatially-resolved spectrometric
data with
different pre-defined distances between the LED and each sensor.
1001791 Going back to Figure 1, in the illustrated exemplary embodiment, probe
1102
is shown as comprising two detectors 1108 with a single LED infrared light
source 1106,
placed on or affixed to a mounting platform or casing 1110 that holds them in
place on the
forehead in proximity to the frontal cortex when the user is wearing headband
1104. While
in this exemplary embodiment, a headband is used, the skilled technician will
understand
that other designs may be used, for example that include smaller patches that
can be affixed
with medical adhesive or through suction cups. Moreover, other body areas may
be targeted
with different means of affixing probe 1102 thereto, without limitation.
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1001801 In addition to probe 1102, platform or casing 1110 of Figure 1 further
contains
the electronics and energy source necessary to power and control probe 1102
and
communicate to an external computer. For example, this may include a digital
processor
1112 communicatively connected to an internal memory 1114, a power source 1116
and a
communication device 1118.
1001811 Digital processor 1112 may be any type of digital processor known in
the art.
This may include low-powered microcontrollers, embedded processors or the
like.
Generally, digital processor 1112 is communicatively linked to probe 1102 so
as to at least
control its operation and sometimes additionally process, at least in part,
the acquired data.
Digital processor 1112 is also communicatively linked to internal memory 1114
which may
contain for example instructions for use thereby. Internal memory 1114 can be
any form
of electronic storage known in the art, or a combination thereof, including
read-only
memory, random-access memory, or flash memory, to name a few examples. Power
source
1116 may comprise one or more rechargeable or non-rechargeable batteries.
Communication device 1118 may be any device operable to transmit data to
another
electronic device. This may include a network adapter for transmitting data
over a wired
(i.e. ethernet) or wireless connection (i.e. Bluetooth or Wi-Fi). It may also
include RF
emitters/transmitters, for example a wireless UART RF module or similar. In
the illustrated
embodiment of Figure 1, communication device 1118 is shown transmitting data
via a
wireless signal 1120 to a remote processing device 1122. The skilled
technician will
understand that other electronic components may also be integrated on headband
1104 as
required. These may include for example DC/DC converters, or any electronic
component
required to optimize the functioning of the components already discussed
above, without
limitation.
1001821 In some embodiments, probe 1102 and its associated electronic
components
may be operable to function in an offline mode in which case the data is
stored on board in
internal memory 1114 for future download once the wireless link is made
available. The
device may also function in an online mode when the wireless connection to
remote device
1122 is available and can allow real-time download of the data acquired for
monitoring and
processing purposes.
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1001831 In some embodiments, remote device 1122 may be any type of a computer
with
a digital display screen, tablet, smartwatch, smartphone or like general
computing device.
It generally comprises its own communication device 1124 configured so as to
communicate with communication device 1118, an internal memory 1126, a digital
processor 1128, some type of display 1130 and one or more input devices 1132
(i.e.
keyboard, mouse, touch screen, etc.). In some embodiments, remote device 1122
may be
operable to receive spectral data acquired by probe 1102 and to process it.
1001841 In some embodiments, as remote device 1122 may not have the constraint
otherwise imposed on a wearable probe such as that provided by headband 1104,
digital
processor 1128 may be more powerful than digital processor 1112 on headband
1104, and
may thus be relied on to provide more demanding tasks such as data analysis or
the like. In
other embodiments, if remote device 1122 is also lightweight (smartwatch,
etc.),
processing may be offloaded, at least in part, to a remote server or similar
(not shown) to
which remote device 1122 is or can be remotely connected.
1001851 With reference to Figure 12, and in accordance with different
embodiments, a
software processing system or engine for processing spectral data, generally
referred to
using the numeral 1200, is discussed. In this exemplary embodiment, processing
system
1200 may be executed on remote device 1122, which is in direct communication
with the
electronics on headband 1104 as mentioned above. More generally, in some
embodiments,
.. processing system 1200 may be in the form of a software interface or
application interface
running or being executed on a computer with a digital display screen, tablet,
smartphone
application or like general computing device, or again a dedicated device
having a
graphical or like general computing device.
1001861 In some embodiments, processing system 1200 may comprise one or more
software modules or features, including for example an analytical engine 1202,
a run
viewer 1204, a database 1206, a graphical user interface (GUI) 1208 and/or a
headband
communication protocol interface 1210.
1001871 In some embodiments, analytical engine module 1202 comprises software
configured or programmed to process spectral data acquired by probe 1102. This
may
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include fitting the spectral data with one or more spectral functions so as to
determine the
spectral contributions from one or more chromophores or molecules. It may also
include
using the identified spectral contributions from each chromophore (and thus a
related
chromophore concentration) to derive one or more related physiological or
health-related
parameters. These may include, without limitation, blood volume, blood flow
rate,
breathing rate, heart rate, and blood pressure and/or any medical condition
related to a
change thereof. In some cases, this may be done using pre-defined analytical
models. In
other cases, machine-learning or artificial intelligence (Al) algorithms may
be used to
derive correlations between these one or more physiological parameters and
said spectral
contributions. Moreover, by combining an analytical model with the high-
resolution
spectral data acquired by probe 1102, absolute measurements are possible, in
contrast with
known methods which rely on relative measurements.
1001881 In some embodiments, run viewer module 1204 is a program operable to
monitor spectral data acquired via probe 1102, in some cases in real-time.
This may include
generating plots or graphical representations of said spectral data. In some
embodiments,
module 1204 may further be used to remotely program or configure probe 1102 or
any
parameter related to the spectral acquisition process (i.e. acquisition
frequency, brightness
of light source 1106, etc.).
1001891 In some embodiments, database module 1206 may include a database
software,
or a database-interfacing program operable to interface with a remote server-
based
database. It may be used to store spectral data acquired via probe 1102 but
also any
processing done thereto via analytical engine 1202. In some embodiments,
previous
measurements may be stored in database 1206 so as to construct a baseline for
one or more
physiological or health-related parameters.
1001901 In some embodiments, processing system 1200 may include a headband
communication protocol interface module 1210. This may include any software
used to
configure or control data transmission between probe 1102 and remote device
1122 (or to
any other computing device), so for example to configure either one of
communication
devices 1118 or 1124. In some embodiments, this may also include configuring
how other
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parameters related to the functioning of any components located on headband
1104 may
also be transmitted. For example, this may include the remaining charge of
power source
1116 or any error messages related to malfunctioning hardware components.
1001911 In some embodiments, processing system 1200 may further comprise a GUI
1210, displayed for example via display 1130, and which may be used to
interact with any
one of modules 1202 to 1208 via a mouse of touchscreen. In some embodiments,
multiple
modules may be interacted with simultaneously via GUI 1208.
1001921 With reference to Figure 13, and in accordance with one embodiment, a
process
for monitoring for one or more health-related parameters with system 1100,
generally
referred to using the numeral 1300, will now be described.
1001931 Initially, at step 1302, a full or broad spectrum of the user or
patient is acquired
via probe 1102. As mentioned above, the exemplary system 1100 is designed so
as to
acquire a full spectrum between 600 nm and 1000 nm. Different resolutions may
be used,
for example and without limitation, a resolution of 5 nm from 600 nm to 1000
nm, or 81
wavelengths in total.
1001941 At step 1304, the acquired spectral signal or data is analyzed or
processed. In
some embodiments, it may be preferable to directly send or transmit the
acquired raw
spectral data to remote device 1122 for analysis (for example to minimize the
power
requirements of wearable digital processor 1112). In other embodiments, the
analysis,
processing or pre-processing (i.e. averaging of multiple acquisitions or
other) of the
acquired spectra may be done, at least in part, via digital processor 1112
located on
headband 1104 before being transmitted.
1001951 As mentioned above, the high spectral resolution provided by system
1100
provides a higher discrimination ability between various chromophores being
monitored.
These may include, without limitation, extracting concentrations for
chromophores like
carbon monoxide, cytochrome oxidase, oxyhemoglobin, deoxyhemoglobin, or other
hemoglobin types, melanin, etc. Blood volume changes can also be monitored,
for
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example, where monitored concentrations remain relatively constant but a
greater or lesser
volume of probed molecules travel across the sensor's field of view over time.
1001961 The high resolution and the large range of the acquired spectrum
allows, for
example, spectral unmixing analysis, wherein the spectral signature can be
broken down
into its constituent spectral components and the relative proportion of each
of these
component spectra can be deduced. This has the unique capability of being able
to extract
known absorption spectra from the at-sensor spectra and find "residual"
signatures with
spectra of unknown origin. Conversely, a spectral signature can be extracted
based only on
its unique feature distribution over the entire IR range. This allows better
estimates of the
material causing that signature. It also allows extraction of spectra with
very broad features
more accurately, which is not readily available using only a few token
wavelengths in a
conventional oximeter, since these broad spectra features are more affected by
confounding
factors. Thus, each spectral component can be resolved or identified. In
combination with
an analytical model, this allows the calculation of absolute values. This is
in contrast with
current cerebral oximetry techniques which rely on the calculation of indices
(regional
saturation, etc.) based on ratios and these can only be relative to baseline
measurements.
This means that values from one patient to another may vary significantly and
comparisons
are therefore not easily done.
1001971 Different functions or functional forms may be used or fitted to the
spectral data
to extract distinct chromophore signatures therein. This may include different
multivariate
analysis methods known in the art for addressing the presence of two or more
chromophore
components having overlapping spectral features.
1001981 Moreover, while conventional cerebral oximeters tend to average
readings or
measurements over a period of several seconds to be able to output a steady
reading, in
contrast, system 1100 may be operable, in some embodiments, to deconvolve the
physiological parameters for each spectral reading acquired at a high
frequency in order to
remove any confounding effect and thus be able to render a high-frequency
reading of all
parameters, which avoids the need to overly average readings to remove those
confounding
effects.
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1001991 The nature of spectroximetry, or hyperspectral oximetry, as in the
case of
system 1100, allows measurement of absolute transmission of energy. Therefore,
intra-
patient and/or inter-patient measurements can be readily taken, for example,
without
significant pre-calibration efforts or techniques.
1002001 Once one or more chromophore absorption levels have been extracted
from the
spectral data, in step 1306, these may be correlated with one or more
physiological or
health-related parameters, or with a change thereof. In some embodiments, the
higher level
of spectral information acquired by system 1100 may allow to derive
correlations with
known clinical data using one or more optimization algorithms, for example
using Al
models or similar (including neural network models or deep-learning models).
1002011 Moreover, since the acquired spectral data covers a large band of
wavelengths,
this allows not only to compare spectra between users or patients, but it also
allows
customization of the diagnostic value or device response to the target
individual.
1002021 These one or more physiological or health-related parameters may
include,
without limitation, blood pressure, blood or tissue oxygenation, pulse, blood
flow rate,
blood loss or hemorrhaging, cognitive assessments, lung efficiency, rate of 02
consumption by the brain or other physiological system being probed, stress
detection,
blackout warnings, CPR monitoring, assessment of vital signs, detection of
strokes, etc.
Some of these will be discussed further below. Moreover, since system 1100 is
operable to
acquire high-frequency spectral data which contains the presence of multiple
chromophore
signatures simultaneously, it may thus allow for a perfect synchronization of
correlations
between the one or more physiological or health-related parameters derived
therefrom.
1002031 In some embodiments, the absolute nature of the absorption spectra
acquired by
probe 1102 may allow to detect blood loss, or hemorrhaging. For example, while
the 5p02
parameter measured using traditional oximetry techniques only considers the
fraction of
the hemoglobin molecules in the oxygenated state and not the total hemoglobin
content, it
cannot provide an absolute reference value from one individual to another.
Indeed, it can
only provide a measure of the portion of hemoglobin molecules which are/are
not
oxygenated. In contrast, system 1100 is operable to provide a more complete
spectrum and
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may thus be able to assess the level of hemoglobin concentration from the
total absorption
of light. In the exemplary case of blood loss, system 1100 may detect the
total concentration
of hemoglobin going down, even when the oxygen saturation remains at 100%.
1002041 In some embodiments, system 1100 may provide diagnostic evaluation via
the
use of bolus type tests in which an "indicator" (e.g. naturally occurring or
foreign tracer
molecule or similar) is introduced in the blood and its effects are measured.
For example,
a patient may receive a shot of high concentration 02, which may be detected
via a spike
in measured venous oxyhemoglobin, which may be detected in the head or other
monitored
region. This type of measurement would not be possible with conventional pulse
oximetry
methods or systems. If the initial amount of 02 introduced is known, system
100 may derive
therefrom a concentration of new oxyhemoglobin, which, combined with a
measurement
of the change in absorption of light in the head (or other region), may be
used to derive a
venous blood optical "thickness" value. The same process may also be done when
monitoring arterial oxyhemoglobin and consequently a corresponding proportion
of arterial
to venous content in the head can be derived. For instance, if the amount of
new arterial
oxyhemoglobin resulting from the "shot" is estimated, then changes measured in
the
oxyhemoglobin absorption can be fitted to a venous volume required to manifest
the total
spectral absorption observed, thereby providing an indication as to arterial
to venous
proportions. Other tests may include, but are not limited to, pulmonary
efficiency, in that
knowing an increase in 02 molecules introduced, one can measure what amount
reaching
the blood (e.g. via spectral absorption) and qualify or quantify a proportion
of the 02 being
absorbed into the blood and a speed or efficiency at which it does. These and
other similar
tests may be done by system 1100 in real-time for each individual.
1002051 In some embodiments, the same "bolus" type test may also be used to
provide
the time of travel between the lungs and a point of interest on the body (e.g.
head;
extremities such as arms, fingers, feet or legs as a function of blood
pressure). This type of
measurement may be used to derive a blood flow rate value, for example.
1002061 Similarly, since blood flow rate is dependent on blood pressure ,
similar
correlations between flow rates and blood pressure may be derived. Currently,
correlations
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derived using a conventional pulse-oxymetry signal and blood pressure are
statistically-
based and use databases of previously measured signals to optimize an
algorithm (such as
Al). In contrast, the full Spectrum approach provided by system 100 is more
versatile as it
is based on direct correlations between different physiological parameters.
1002071 In some embodiments, detected changes in oxyhemoglobin and
deoxyhemoglobin may be combined with the 02 content being breathed (e.g. the
%02 being
breathed), to derive a level of dissolved oxygen in the blood.
1002081 In some embodiments, system 1100 may be configured to detect an
increase in
the optical density related to oxyhemoglobin in the venous blood, and may use
the
concentration of 02 being breathed (e.g. the %02 being breathed), to derive a
corresponding
hemoglobin concentration. This may also be done when measuring a decrease in
optical
density of oxyhemoglobin with a decreasing concentration of 02 being breathed.
1002091 In some embodiments, system 1100 may be used to monitor 02 delivery.
For
example, in some clinical settings, it may be desirable to administer 02 to a
patient to
increase the partial pressure of 02 in the patient's lungs and the blood.
However, elevated
concentrations of 02 in the blood for prolonged time are known to have
detrimental effects.
Conventional pulse oximeters are not able to show if the patient is in a
hyperoxic state (or
above partial pressure of 0.21 ATA). In contrast, full spectrum oximetry as
provided by
system 1100 may be operable to track elevated 02 states. It may also be
operable to detect
dropping 02 levels before a hypoxic state is even reached, in contrast to a
pulse oximeter
that would typically only be able to detect the hypoxic state once reached.
1002101 In some embodiments, system 1100 may be used in hyperbaric medicine.
For
example, in some embodiments, system 100 may be configured to track hyperoxic
states
well above a 02 partial pressure of 0.21 ATA, thus allowing the monitoring of
how close
the patient is to hazardous levels of oxygen toxicity.
1002111 In some embodiments, system 1100 may be used for cognitive assessment
during sports or in extreme environments. For example, system 1100 may be
configured to
provide assessment of oxygenation levels during exercise. It is well known
that
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conventional oximetry does not see or detect increases in blood oxygenation
beyond Sp02
of 100%, which is very close to the value anyone has normally at rest. In
contrast, system
1100 may be operable to see or detect increases in the level of oxyhemoglobin
reaching the
organ of interest (e.g. brain) in a specified unit of time during exercise.
For instance, this
may be used to indicate an increase in blood flow, and thus of oxyhemoglobin,
to the organ
under observation, which translates in a greater delivery of 02 to that organ.
Thus, in some
embodiments, system 1100 may be used to monitor or assess the level of
increased
oxygenation from one activity to another, which may be used to create a
baseline by finding
normal increases in oxygen delivery to the brain (or other organs) using a
sample
population. Thus, measurements from an individual may be compared to this
baseline and
this used to assess performance, impairments, etc.
1002121 In some embodiments, system 1100 may be configured to monitor the rate
of
02 consumption in the brain or other organ of interest. For example, with
normal air,
arterial blood is almost 100% saturated. If 100% 02 is breathed, the venous
deoxyhemoglobin in the organ will decrease by an amount proportional to the
amount of
02 not metabolized by the tissue under study.. Thus, by knowing the input
quantity or
amount of air and knowing what is left over from the dissolved 02 that went
back into the
venous hemoglobin (thus raising its oxyhemoglobin content), system 1100 may be
configured to derive the portion of 02 taken up by the organ of interest. In
some
embodiments, this may be done on a population sample which may then be used as
a
reference or baseline for diagnostic of other individuals.
1002131 In some embodiments, system 1100 may be operable to derive a lung
efficiency
value or similar.
1002141 By introducing a known increase in 02 content being breathed and
measuring
the effective change in oxy and deoxy hemoglobin, and if applicable knowing
the
metabolized amount in the tissue under investigation, system 100 may derive
therefrom a
measure of efficiency of 02 transfer occurring at the pulmonary level.
Conversely, 02
intake may be reduced and system 100 used to monitor the corresponding
decrease of
oxyhemoglobin optical density in the arteries.
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1002151 In some embodiments, system 1100 may be operable to derive a
concentration
of 02 breathed. This may be done as described above for assessing lung
efficiency, but here
assuming a fixed level of lung efficiency to derive the concentration being
breathed. In
some embodiments, system 1100 may thus be combined or used in conjunction with
a
rebreather diving apparatus or similar.
1002161 In some embodiments, system 1100 may be used for stress detection and
assessment. For example, stress in a user or patient impacts physiological
parameters such
as pulse, respiration, and blood flow rate. All these parameters may be
correlated to the
spectra recorded via system 1100. An assessment on the stress level can be
made using a
combination of known states for each parameter as well as known changes to
these
parameters (i.e. sudden increase in heart rate and breathing).
1002171 In some embodiments, system 1100 may be configured to alert for
imminent
blackout in an individual or user. The onset of blackout in a user may be
predicted based
on the oxygenation state of the person. For example, for military pilots, a
drop of blood
flow to the brain, or a drop in oxygenation levels may be used to mitigate
risk of blackouts.
1002181 In some embodiments, system 1100 may be used to monitor
cardiopulmonary
resuscitation (CPR) maneuvers or the like. Currently, CPR is performed using
set
recommended protocols and procedures for the frequency of chest compressions
and
mouth-to-mouth assisted breathing. These protocols are established based on
experience.
Means for an assessment of the performance of CPR given to a patient in real-
time while
CPR is administered can significantly improve patient outcome. The protocol
could be
adapted to the patient's needs given specific scenario and response. However,
one of the
problems with traditional cerebral oximetry is the lack of common baseline
from one
patient to another. It is also not clear what values given by one instrument
should be used
as target since (1) the index is relative, (2) indices are not calculated the
same way, (3) the
same index can vary from one device to the next due to design factors, (4)
lack of clinical
studies across all devices, (5) variability in readings from one patient to
another using the
same device given skin type, ethnic background, etc. Another significant
disadvantage of
traditional cerebral oximetry is the fact that the index typically is
calculated using an
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integration time significantly longer than a normal heartbeat. Sensitivity to
minute changes
in hemoglobin is therefore compromised. Finally, conventional pulse oximetry
will not
work when the patient has weak or no pulse.
1002191 Full spectrum oximetry as provided by system 1100 may allow for the
instantaneous assessment of vital signs. For example, by deconvolving spectral
signatures,
individual contribution of each type of chromophore may be measured. High-
frequency
measurements can see variations in blood flow that could be indicative of
chest
compressions. This approach can also define a target "absolute index" of
absorption in the
brain caused by oxyhemoglobin, blood flow, and other useful parameters. This
index can
be then be used for all individuals.
1002201 In some embodiments, system 1100 may be configured to detect strokes
resulting from the blockage of blood flow to the brain. As discussed above,
reduction of
blood flow may be derived by system 1100 via a significant reduction in
absorption of key
spectral indicators.
1002211 With reference to Figures 14 to 16, and in accordance with one
exemplary
embodiment, an exemplary set of measurements acquired using an exemplary
embodiment
of system 1100 will be discussed.
1002221 Figure 14 shows an exemplary plot of multiple spectral transmission
curves
acquired at the cerebral level for a user wearing system 1100 breathing normal
air while
being in a seated position. The plot shows randomly acquired spectra over a
two-minute
period. The time sampling of repeated measurements (i.e. different curves)
shows
variations that are due to the inherent physiological changes caused by
varying blood flow
(heart beats, blood pressure, etc.), breathing rate, and other such normal
body functions.
Spectra taken at various times therefore will show variations in the acquired
spectra due to
these inherent physiological changes. This allows to derive values for
physiological
parameters such as pulse, blood flow, head orientation, blood volume, blood
pressure, etc.
with adequate modeling, since the spectral differences can be used to derive
the
physiological parameters that affect these readings such as pulse, blood
volume, blood
volume, blood pressure, etc.
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1002231 In some embodiments, the transmission curve of normal air at 21%
(Figure 14)
can represent a baseline to which changes arising from different 02
concentration can be
interpreted.
1002241 With reference to Figure 15, a plot showing an average change of
spectral
readings when switching from normal air breathing, as seen in the previous
Figure 14, to
breathing a hypoxic gas that contains 5% 02 will now be discussed. Breathing a
hypoxic
gas results in a significant lowering of the level of oxygen reaching the
blood and tissues.
The plot of Figure 15 shows the progressive change in spectral readings with
line 502
representing an average of multiple spectra taken during one-minute breathing
air in a
sitting position as in the previous plot of Figure 14. Meanwhile, line 503
shows the average
of multiple spectra taken after a minute of breathing the hypoxic mix.
Finally, line 504 is
the average of multiple spectra taken after breathing 4 minutes of the hypoxic
mix. In this
case, there is a clear decrease in the transmission in the 700 nm area which
is consistent
with an increase in absorption due to elevated deoxyhemoglobin levels.
1002251 Similarly, Figure 16 is a plot showing various acquired spectra when
the user
switches from breathing normal air (21%) to breathing pure oxygen (100%). Line
602
shows the average of multiple spectra taken during the first minute of
breathing normal air.
Lines 604 and 606 are the average of multiple spectra acquired during the
first and third
minutes, respectively. Line 608 is the average of multiple spectra acquired
during the fifth
minute of breathing pure oxygen. While conventional pulse oximeters, as well
as cerebral
oximeters would not show significant change in these conditions, the full-
spectrometric
signals acquired via system 1100 clearly show the progressive change related
to the
changing breathing conditions.
1002261 In light of the above, and accordance with one embodiment, a device
for real-
time vital sign monitoring for individuals in extreme and/or harsh
environments is
provided, whereby such environments expose users to anomalous environmental
respiratory conditions, as described above. Namely, within this context,
extreme
environments may include any situation where an individual is experiencing
lower or
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higher ambient pressures or requires delivery of oxygen from an external
source. For
example, these situations include high altitude pilots and underwater divers.
1002271 In one such embodiment, the device can detect and track multiple vital
signs
including heart rate, breathing rate, temperature, and oxygenation. The device
consists of
a custom light source and a series of optical detectors that operate in a wide
range of
frequencies, as further detailed below, for example. Light reaching the
detectors at specific
frequency ranges is tracked and used to derive the physiological parameters of
interest,
namely those representative of the user's current and/or cumulative
physiological response
to exposure to the anomalous environmental respiratory conditions. As further
detailed
.. below, in this embodiment, operation of the device's optical physiological
sensing and
monitoring system differs from conventional oximetry in that the device is not
dependent
on the detection of a pulse to acquire meaningful data.
1002281 In one particular embodiment, measurements are made directly at the
cerebral
level. Consequently, the device is designed to be worn on the forehead where
it can be
integrated into existing equipment (mask, hoodie, HUD unit, etc.) or as a
standalone patch.
The device is not limited to this placement and can be also put elsewhere on
the body.
Outside the scope of underwater applications, the device can also be used for
the
monitoring of pilot cognitive performance, for example. The device can
generally be used
in any scenario requiring real-time continuous physiological monitoring.
1002291 As introduced above, the device is operable to track oxygen levels in
both
hypoxic as well as hyperoxic conditions. For this reason, the device is
amenable for
underwater environments where divers are exposed to significant dangers due to
oxygen
toxicity.
1002301 There are generally no current devices that can track higher than
normal
oxygenation levels in a non-invasive and continuous manner. Conventional
measurement
of oxygenation consists of detecting arterial saturation (Sp02) using a pulse
oximeter
placed on the extremities of the body (fingers, toes, ear lobes, etc.). In the
context of diving,
Sp02 is not very useful as it is only indicative of arterial oxyhemoglobin
levels, can only
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be used for hypoxia, and is ineffective in cases of reduced blood circulation
such as in cold
temperatures.
1002311 Comparatively, devices as described herein in accordance with some
embodiments, are operable to detect and track hyperoxia resulting from 02
partial pressures
well above 0.21 ATA as experienced in diving applications.
1002321 Accordingly, the device represents a complete vital sign monitoring
solution
and allows for a continuous adaptation of a dive profile, for example, to the
actual
physiological condition of the diver in open, semi-closed, and closed circuit
scenarios,
while also mitigating the dangers of hyperoxia.
1002331 To demonstrate the tracking of oxygen during hyperoxia, the herein-
described
approaches were tested in real underwater environments and in hyperbaric
chambers. As
an example, Figure 8 (described above) shows data acquired during a dive in a
hyperbaric
chamber. The diver is initially at the surface breathing air. A first descent
reaches 30 feet
(t=600 sec.). After a few minutes, the diver switches to 100% 02 while the
depth is kept
unchanged. The diver is then brought up to 15 feet where a switch back to air
occurs after
a few minutes. For reference, the breathing gas and partial pressure (p02) at
each depth is
indicated on the graph. It can be readily observed that the light transmission
detected by
the device correlates directly to the changes in oxygen experienced by the
diver.
1002341 Two features can be highlighted in Figure 8. First is the fact that
the device
follows the changes in oxygen levels actually experienced by the diver at a
physiological
level and not through any derivation based on depth and gas mix. For example,
when the
first switch from air to 100% occurs, the transmission levels are instantly
reduced
(indicating increased oxygen) while the atmospheric pressure remains that of
30 feet depth.
1002351 Secondly, the device provides a means to track and mitigate long term
exposure
to 02. This is demonstrated by comparing the first period in which the diver
is breathing
air at 30 feet pressure and the last period where the diver is breathing air
at 15 feet pressure.
Based only on depth and gas mix, it would be expected that the level of oxygen
exposure
in the diver's system is less in the latter period at 15 feet than in the
initial period at 30 feet.
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The acquired data however shows slightly increased levels of 02 exposure at 15
feet. The
cause of this is explained by residual 02 in the diver's system resulting from
high exposure
while breathing 100% 02. To our knowledge this figure is the first such
recorded evidence
demonstrating that partial pressure based on gas mix and depth alone is not
sufficient to
assess a diver's true exposure to oxygen and risks of oxygen toxicity.
1002361 Using this approach, the device is capable of monitoring all vital
signs in real-
time during a dive and allow for a continuous adaptation of the dive profile
to the actual
physiological condition of the diver. For example, the diver's real-time
physiological data
can feedback into the rebreather or dive computer to continuously adapt the
dive to the
actual physiological state of the diver, independently of the sensors onboard
the rebreather.
1002371 Tests were conducted to demonstrate the impact of the level of
physical activity
on oxygen exposure and its associated risks in hyperoxic conditions. For
example, Figure
9 (described above) shows the synchronous tracking of oxygenation, heart rate,
and
breathing rate as the diver increases the level of physical exertion. The
diver descended to
57 feet and performed intense physical activity without altering depth or
breathing gas.
Shortly after the onset of the physical activity, both the heart rate (middle
curve) and the
breathing rate (bottom curve) increased sharply. This led to a detectable
increase in
oxygenation shown by the decrease in light transmission (to curve). The
increase in
oxygenation is steady and continuous throughout the period of intense
activity.
1002381 This data suggests the importance of accounting for physiological
parameters
in the assessment of oxygen exposure and risks of oxygen toxicity.
1002391 Accordingly, a computational process as described herein that can take
physiological parameters into account can compensate for the variability of a
diver's
reaction to the same dive conditions at different times. Actionable decisions
can then be
tailored to the diver's specific condition at a given time. Actionable
decisions can include
but are not limited to: surface, reduce depth, or allow increased depth;
prolong or reduce
dive time, alter gas mix; reduce physical activity; etc.
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1002401 This device allows the significant improvement adding physiological
parameters to the current approaches for dive management that are otherwise
solely based
on environmental conditions (pressure, running time, etc.). Whereas existing
algorithms
make assumptions based on theoretical models of the physiological reactions to
environmental conditions, this approach allows new algorithms that take into
account the
actual physiological parameters as they are being measured in real-time while
the diver is
exposed to environmental stresses.
1002411 Several advantages to real-time physiology-adapted dive management may
thus
include, but are not limited to, any combination of: Enhanced prediction of
hazardous
health states; Optimal physical performance; Ability to train Machine-Learning
algorithms
(Artificial Intelligence) to tailor predictions to individual divers; Unique
customized
adapted profiles based on day-to-day conditions; Tracking of performance
enhancement
over time; Detection of anomalies based on history of physiological response;
Objective
comparison between diver performances; Etc.
1002421 While the present disclosure describes various embodiments for
illustrative
purposes, such description is not intended to be limited to such embodiments.
On the
contrary, the applicant's teachings described and illustrated herein
encompass various
alternatives, modifications, and equivalents, without departing from the
embodiments, the
general scope of which is defined in the appended claims. Except to the extent
necessary
or inherent in the processes themselves, no particular order to steps or
stages of methods
or processes described in this disclosure is intended or implied. In many
cases the order of
process steps may be varied without changing the purpose, effect, or import of
the methods
described.
1002431 Information as herein shown and described in detail is fully capable
of
attaining the above-described object of the present disclosure, the presently
preferred
embodiment of the present disclosure, and is, thus, representative of the
subject matter
which is broadly contemplated by the present disclosure. The scope of the
present
disclosure fully encompasses other embodiments which may become apparent to
those
skilled in the art, and is to be limited, accordingly, by nothing other than
the appended claims,
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wherein any reference to an element being made in the singular is not intended
to mean
"one and only one" unless explicitly so stated, but rather "one or more." All
structural
and functional equivalents to the elements of the above-described preferred
embodiment
and additional embodiments as regarded by those of ordinary skill in the art
are hereby
expressly incorporated by reference and are intended to be encompassed by the
present
claims. Moreover, no requirement exists for a system or method to address each
and
every problem sought to be resolved by the present disclosure, for such to be
encompassed
by the present claims. Furthermore, no element, component, or method step in
the present
disclosure is intended to be dedicated to the public regardless of whether the
element,
.. component, or method step is explicitly recited in the claims. However,
that various
changes and modifications in form, material, work-piece, and fabrication
material detail may
be made, without departing from the spirit and scope of the present
disclosure, as set forth
in the appended claims, as may be apparent to those of ordinary skill in the
art, are also
encompassed by the disclosure.
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