Note: Descriptions are shown in the official language in which they were submitted.
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TITLE: METHOD AND APPARATUS FOR PROVIDING CONTRACTION
INFORMATION DURING LABOUR
FIELD OF THE INVENTION
The present invention relates generally to the field of obstetrics and, more
specifically, to a method and apparatus for monitoring labor progression and
for
providing a user interface to display data conveying maternal information
during
labor.
BACKGROUND
Uterine contractions are intermittent and co-ordinated tightenings of the
uterine
muscle. Uterine contractions provide the force that makes labour progress, by
causing
the baby to descend through the birth canal and making the cervix efface
(shorten),
and dilate (open). This force is related to the frequency, strength and
duration of the
contractions. Oxytocin is a natural hormone that causes uterine contractions.
A
synthetic version of oxytocin is often administered during labour to increase
the
frequency, duration and strength of uterine contractions or to induce labour.
The
medication is administered through a continuous intravenous infusion. There is
no
fixed dosage as in antibiotic therapy; rather the dose is adjusted frequently
according
to the patient's response to achieve the desired frequency and intensity of
contractions.
When the uterine muscle contracts, the maternal blood vessels in it are
constricted
causing a temporary reduction in the blood flow and delivery of oxygen to the
baby's
placenta. Relaxation of the contraction restores the flow and oxygen delivery
to the
baby. In normal circumstances, babies tolerate contractions well. However, in
other
circumstances, such as when the placenta malfunctions or the contractions are
excessively frequent with little or no relaxation time between them, the baby
may not
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tolerate this reduction in oxygen delivery. If the situation remains
uncorrected or
worsens it may result in injury to the baby's brain and permanent disability.
At present, clinical staff estimates the frequency of contractions by feeling
the
mother's abdomen for a few minutes and noting the timing of a few contractions
or by
examining a paper tracing that shows a recording of contraction
pressures/intensity
over time. These assessments are performed periodically and the results
recorded in
the medical record.
A deficiency with the above-described methods for assessing contraction
frequency is
that they are prone to inaccuracy and incompleteness because they are visual
estimates based on short selected segments of the tracing and the caregiver
may fail to
make assessments at the prescribed time intervals and may fail to appreciate
the
degree and duration of the abnormality as well as the response of the baby.
Thus,
there can be a delay or failure to recognize overly frequent contractions, to
adjust the
medication correctly, resulting in an iatrogenic injury to the baby.
In the context of the above, there is a need to provide a method and device
for
monitoring contractions for an obstetrics patient that alleviates at least in
part
problems associated with the existing methods and devices.
SUMMARY OF THE INVENTION
In accordance with a first broad aspect, the invention provides a computer
readable
storage medium storing a program element suitable for execution by a CPU where
the
program element implements a graphical user interface module for displaying
uterine
contraction information. The graphical user interface module is adapted for
receiving
a contraction signal conveying information related to occurrences of uterine
contractions over time. The graphical user interface module is adapted for
displaying
first information conveying a rate of uterine contractions, the first
information being
derived at least in part on the basis of at least a portion of the contraction
signal. The
graphical user interface module is also adapted for displaying, concurrently
with the
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first information, second information conveying a threshold rate of uterine
contractions. The
graphical user interface module is also adapted selectively causing an alarm
event based at least in
part on a rate of uterine contractions conveyed by the first information and
the threshold rate of
uterine contractions.
An advantage of this first aspect is that it allows clinical staff making use
of the graphical user
interface module to readily track contraction rates and be provided with an
indication, through the
display of the threshold rate of uterine contractions, of a boundary defining
safe care. As such, the
clinical staff is enabled to more easily assess labour progress. More
specifically, the display of the
graphical user interface module allows the clinical staff to readily ascertain
when the contraction
rate falls outside a limit set by the threshold rate of uterine contractions
and, therefore, allows the
clinical staff to take the necessary action in response to the occurrence of
this event. In specific
practical implementation, the threshold rate of uterine contractions will be
set by hospital policy
and/or on the basis of recognized best practices. The graphical user interface
module also provides
an improved method for alerting the staff to conditions requiring intervention
by causing an alarm
event.
In accordance with specific examples of implementation, the graphical user
interface module may
cause an alarm event in response to a rate of uterine contractions conveyed by
the first information
falling outside a limit set by the threshold rate of uterine contractions.
Alternatively, the graphical
user interface module may cause an alarm event in response to a rate of
uterine contractions
conveyed by the first information exceeding the threshold rate of uterine
contractions.
Alternatively, the graphical user interface module may cause an alarm event in
response to a rate of
uterine contractions conveyed by the first information falling outside a limit
set by the threshold rate
of uterine contractions for a time duration exceeding a predetermined time
duration.
Advantageously, this second alternative allows the graphical user interface
module to take into
account a prolonged duration of an anomalous contraction rate when causing an
alarm event.
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In accordance with specific examples of implementation, the graphical user
interface
module receives contraction medication information conveying information
associated to administration of contraction inducing medication to the
obstetrics
patient. The contraction medication information may indicate whether
contraction-
inducing medication was administered and, optionally, a dosage of the
contraction
inducing medication administered. The graphical user interface module
selectively
causes an alarm event based at least in part on a rate of uterine contractions
conveyed
by the first information, on the threshold rate of uterine contractions and on
the
contraction medication information.
Advantageously, this alternative implementation allows the graphical user
interface
module to take into account whether contraction inducing medication was
administered to the obstetrics patient being monitored (and optionally the
amount of
contraction inducing medication which was administered) when causing an alarm
event.
In accordance with another specific examples of implementation, the graphical
user
interface module receives fetal heart rate information. The graphical user
interface
module selectively causes an alarm event based at least in part on a rate of
uterine
contractions conveyed by the first information, on the threshold rate of
uterine
contractions and on the fetal heart rate information. The fetal heart rate
information
may including a fetal heart rate signal or, alternatively, may include
information
conveying a level of risk associated with the fetus, the level of risk being
derived on
the basis of a fetal heart rate signal. Where the fetal heart rate information
includes a
fetal heart rate signal, the graphical user interface module is adapted for
processing
the signal to determine a level of risk associated with the fetal heart rate
signal. Any
suitable method for assessing a level of risk on the basis of a fetal heart
rate signal
may be used. For example, the level of risk may be based on the frequency of
the
fetal heart rate, whether it is too high or too low for a certain period of
time.
Alternatively, the level of risk may be based on other suitable known methods.
A
non-limiting example of a method for providing an indication of the level of
risk is
described in U.S. patent no. 7,113,819, entitled "Method and apparatus for
monitoring
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.
,
,
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the condition of a fetus", issued on September 26, 2006 to E. Hamilton et al.
and assigned to LMS
Medical Systems Ltd. Other suitable methods for assessing a level of risk on
the basis of a fetal
heart rate signal may be used in alternative implementations of the invention.
Advantageously, the above-described alternative implementation allows the
graphical user interface
module to take into account the behaviour of the fetal heart rate, and
therefore the response of the
baby, in combination with the contraction rate when causing an alarm event.
In accordance with another specific examples of implementation, the graphical
user interface
module receives fetal heart rate information and contraction medication
information. The graphical
user interface module selectively causes an alarm event based at least in part
on a rate of uterine
contractions conveyed by the first information, on the threshold rate of
uterine contractions, on the
fetal heart rate information and on the contraction medication information.
In accordance with specific examples of implementation, the alarm event may
include displaying a
visual indicator, causing an audio signal to be issued and/or causing a
message signal to be
transmitted to a remote device. The remote device may be any device suitable
for conveying
information to its user. Examples of remote devices include, without being
limited to, PDAs,
telephones, pager and computing terminals.
In accordance with a first specific example of implementation, the first
information includes a first
tracing conveying rates of uterine contractions over time and the second
information includes a
second tracing conveying the threshold rate of uterine contractions. The first
tracing and the second
tracing are displayed in a same viewing window.
Advantageously, the first and second tracings displayed a same viewing window
allow the clinical
staff to readily ascertain the contraction rate and variations thereof
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over an extended time period. This allows the clinical staff to more easily
distinguish
between short-term variations in contraction rate, which could signal
innocuous
transient states and long term persistence and trends in the contraction rate.
In
addition, this allows the clinical staff to have a more complete view of the
history of
the contraction rate since labour onset, or at least since the clinical staff
was
monitoring the labour. For example, this allows determining whether the
contraction
rate is consistently above the threshold rate or whether it was merely a
temporary
increase in contraction rate and was induced either through the administration
of
medication or other method.
In accordance with a specific implementation, the graphical user interface
module is
operative for processing the contraction signal to derive a set of contraction
rate data
elements, each contraction rate data element being associated to a segment of
the
contraction signal. The graphical user interface module causes an alarm event
in
response to at least one contraction rate data element in the set of
contraction rate data
elements falling outside a limit set by the threshold rate.
In accordance with a second specific example of implementation, the first
information
and the second information include alphanumeric characters for conveying rates
of
uterine contractions over time and a threshold rate of uterine contractions.
In accordance with another broad aspect, the invention provides a method for
displaying uterine contraction information. The method comprises receiving a
contraction signal conveying information related to occurrences of uterine
contractions over time. The method also comprises displaying first information
conveying a rate of uterine contractions, the first information being derived
at least in
part on the basis of at least a portion of the contraction signal. The method
also
comprises displaying, concurrently with the first information, second
information
conveying a threshold rate of uterine contractions. The method also comprises
selectively causing an alarm event based at least in part on a rate of uterine
contractions conveyed by the first information and the threshold rate of
uterine
contractions.
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In accordance with another broad aspect, the invention provides an apparatus
for
displaying uterine contraction information in accordance with the above-
described
method.
In accordance with another broad aspect, the invention provides a labour
monitoring
system. The system includes a sensor for receiving information indicative of
occurrences of uterine contractions over time. The system also includes an
apparatus
for implementing a user interface for displaying uterine contraction
infoimation. The
apparatus comprises an input in communication with the sensor for receiving a
contraction signal conveying information related to occurrences of uterine
contractions over time. The apparatus also comprises a processing unit in
communication with the input. The processing unit implements a graphical user
interface module for displaying uterine contraction information. The graphical
user
interface module is adapted for displaying first information conveying a rate
of
uterine contractions, the first information being derived at least in part on
the basis of
at least a portion of the contraction signal. The graphical user interface
module is also
adapted for displaying, concurrently with the first information, second
information
conveying a threshold rate of uterine contractions. The graphical user
interface
module is also adapted for selectively causing an alarm event based at least
in part on
a rate of uterine contractions conveyed by the first information and the
threshold rate
of uterine contractions. The apparatus includes an output in communication
with the
processing unit for releasing a signal for causing a display unit to display
the
graphical user interface module. The system also includes a display unit in
communication with the output of the apparatus. The display unit is responsive
to the
signal releasing by the output of the apparatus to display the graphical user
interface
module.
In accordance with yet another broad aspect, the invention provides a server
system
implementing a graphical user interface module for displaying uterine
contraction
information. The server system stores a program element for execution by a
CPU.
The program element includes a plurality of program element components. A
first
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program element component is for receiving a contraction signal conveying
infonnation related to occurrences of uterine contractions over time. A second
program element component is for processing the contraction signal and issue a
signal
for displaying:
¨ first information conveying a rate of uterine contractions, the first
information
being derived at least in part on the basis of at least a portion of the
contraction
signal; and
¨ displaying, concurrently with the first information, second information
conveying
a threshold rate of uterine contractions;
A third program element component is for selectively causing an alarm event
based at
least in part on a rate of uterine contractions conveyed by the first
information and the
threshold rate of uterine contractions.
In accordance with yet another broad aspect, the invention provides a client-
server
system for implementing a graphical user interface module for displaying
uterine
contraction information. The client-server system comprises a client system
and a
server system operative to exchange messages over a data network. The server
system stores a program element for execution by a CPU. The program element
includes a plurality of program element components. A first program element
component is for execution on the server system and is for receiving a
contraction
signal conveying information related to occurrences of uterine contractions
over time.
A second program element component is for execution on the server system and
is for
sending messages to the client system for causing the client system to:
i) display first information conveying a rate of uterine contractions, the
first
information being derived at least in part on the basis of at least a portion
of the contraction signal; and
ii) display, concurrently with the first information, second information
conveying a threshold rate of uterine contractions.
A third program element component is for execution on the server system and is
for
selectively sending messages to the client system for causing an alarm event
based at
least in part on a rate of uterine contractions conveyed by the first
information and the
threshold rate of uterine contractions.
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In a specific implementation, the client-server system includes a plurality of
client
systems operative to exchange messages with the server system over a data
network.
The data network may be of any suitable network configuration including
Intranets
and the Internet.
In accordance with another broad aspect, the invention provides an apparatus
for
implementing a user interface for displaying uterine contraction information.
The
apparatus comprises means for receiving a contraction signal conveying
information
related to occurrences of uterine contractions over time and means for
implementing a
graphical user interface module for displaying uterine contraction
information. The
graphical user interface module is adapted for displaying first information
conveying
a rate of uterine contractions, the first information being derived at least
in part on the
basis of at least a portion of the contraction signal. The graphical user
interface
module is also adapted for displaying concurrently with the first information,
second
information conveying a threshold rate of uterine contractions. The graphical
user
interface module is also adapted for selectively causing an alarm event based
at least
in part on a rate of uterine contractions conveyed by the first information
and the
threshold rate of uterine contractions. The apparatus also includes means for
releasing a signal for causing a display unit to display the graphical user
interface
module.
In accordance with yet another broad aspect, the invention provides a method
for
displaying uterine contraction information. The method comprises transmitting
to a
remote computing unit a contraction signal conveying information related to
occurrences of uterine contractions over time. The method also comprises
receiving
first information conveying a rate of uterine contractions, the first
information
corresponding to at least a portion of the contraction signal. The method also
comprises displaying a graphical user interface conveying the first
information and a
threshold rate of uterine contractions. The method also comprises receiving a
signal
suitable for causing an alarm event based at least in part on a rate of
uterine
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contractions conveyed by the first information and the threshold rate of
uterine contractions.
In accordance with another broad aspect, the invention provides a computer
readable storage
medium storing a program element suitable for execution by a CPU, the program
element
implementing a graphical user interface module for displaying uterine
contraction information. The
graphical user interface module is adapted for receiving a contraction signal
conveying information
related to uterine contractions over time. The graphical user interface module
is also adapted for
processing the contraction signal to derive first information conveying rates
of uterine contractions
over time and for displaying the first information in a viewing window. The
graphical user interface
module is also adapted for displaying concurrently with the first information,
second information
conveying a threshold rate of uterine contractions.
In accordance with another broad aspect, the invention provides a computer
readable storage
medium storing a program element suitable for execution by a processor. When
executed by the
processor, the program element implements a process for monitoring an
obstetrics patient during
labour. The program element when executed by the processor configures the
processor for
monitoring contractions of the obstetrics patient during labor. The monitoring
includes receiving a
contraction signal associated with the obstetrics patient, the contraction
signal conveying
information related to uterine contractions over time. The monitoring of the
contractions also
includes processing the contraction signal to derive first information
conveying rates of uterine
contractions over time and for deriving second information conveying if an
anomalous contraction
rate has persisted for a prolonged period of time. The second information is
derived at least in part
by processing the first information to determine if the rates of uterine
contractions conveyed by the
first information fall outside a limit set by a threshold rate of uterine
contractions for a time duration
exceeding a predetermined time duration. The program element, when executed by
the processor,
also configures the processor for causing the first information to be
displayed in a viewing window
on a display device and for selectively causing an alarm event at least in
part based
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on the second information to convey that the anomalous contraction rate has
persisted for the
prolonged period of time. The alarm event includes at least one of:
i) causing a visual indicator to be displayed, the visual indicator conveying
that that the
anomalous contraction rate has persisted for the prolonged period of time;
ii) causing an audio signal to be issued by an audio speaker, the audio signal
conveying that
that the anomalous contraction rate has persisted for the prolonged period of
time;
iii) transmitting an electronic message over a computer network to a remote
device, the
electronic message conveying that that the anomalous contraction rate has
persisted for
the prolonged period of time.
In accordance with another broad aspect, the invention provides an apparatus
for monitoring an
obstetrics patient during labour. The apparatus comprises an input in
communication with a
contraction sensor for receiving a contraction signal associated with the
obstetrics patient during
labour, the contraction signal conveying information related to uterine
contractions over time. The
apparatus also comprises a processing unit in communication with the input.
The processing unit is
programmed for processing the contraction signal to derive first information
conveying rates of
uterine contractions over time. The processing unit is also programmed for
deriving second
information conveying if an anomalous contraction rate has persisted for a
prolonged period of time.
The second information is derived at least in part by processing the first
information to determine if
the rates of uterine contractions conveyed by the first information fall
outside a limit set by a
threshold rate of uterine contractions for a time duration exceeding a
predetermined time duration.
The processing unit is also programmed for causing the first information to be
displayed in a
viewing window on a display device. The processing unit is further programmed
for selectively
causing an alarm event at least in part based on the second information to
convey that the anomalous
contraction rate has persisted for the prolonged period of time. The alarm
event includes at least one
of:
i) causing a visual indicator to be displayed, the visual indicator conveying
that that the
anomalous contraction rate has persisted for the prolonged period of time;
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ii) causing an audio signal to be issued by an audio speaker, the audio
signal
conveying that that the anomalous contraction rate has persisted for the
prolonged
period of time;
iii) transmitting an electronic message over a computer network to a remote
device,
the electronic message conveying that the anomalous contraction rate has
persisted for the prolonged period of time.
In accordance with another broad aspect, the invention provides a method for
monitoring an
obstetrics patient during labour. The method comprises monitoring contractions
of the obstetrics
patient during labour. The monitoring includes receiving a contraction signal
associated with the
obstetrics patient, the contraction signal conveying information related to
uterine contractions over
time. The monitoring also includes processing the contraction signal to derive
first information
conveying rates of uterine contractions over time. The method further
comprises deriving second
information conveying if an anomalous contraction rate has persisted for a
prolonged period of time,
the second information being derived at least in part by processing the first
information to determine
if the rates of uterine contractions conveyed by the first information fall
outside a limit set by a
threshold rate of uterine contractions for a time duration exceeding a
predetermined time duration.
The method also comprises causing the first information to be displayed in a
viewing window on a
display device. The method further comprises selectively causing an alarm
event at least in part
based on the second information to convey that the anomalous contraction rate
has persisted for the
prolonged period of time. The alarm event includes at least one of:
i) causing a visual indicator to be displayed, the visual indicator
conveying that that
the anomalous contraction rate has persisted for the prolonged period of time;
ii) causing an audio signal to be issued by an audio speaker, the audio
signal
conveying that that the anomalous contraction rate has persisted for the
prolonged period of time;
iii) transmitting an electronic message over a computer network to a remote
device, the electronic message conveying that the anomalous contraction rate
has persisted for the prolonged period of time.
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In accordance with another broad aspect, the invention provides an apparatus
for monitoring an
obstetrics patient during labour. The apparatus comprises means in
communication with a
contraction sensor for receiving a contraction signal associated with the
obstetrics patient during
labour, the contraction signal conveying information related to uterine
contractions over time. The
apparatus also comprises means for processing the contraction signal to derive
first information
conveying rates of uterine contractions over time. The apparatus further
comprises means for
deriving second information conveying if an anomalous contraction rate has
persisted for a
prolonged period of time, the second information being derived at least in
part by processing the
first information to determine if the rates of uterine contractions conveyed
by the first information
fall outside a limit set by a threshold rate of uterine contractions for a
time duration exceeding a
predetermined time duration. The apparatus also comprises means for causing
the first information
to be displayed in a viewing window on a display device. The apparatus also
comprises means for
selectively causing an alarm event at least in part based on the second
information to convey that the
anomalous contraction rate has persisted for the prolonged period of time. The
alarm event includes
at least one of:
i) causing a visual indicator to be displayed, the visual indicator conveying
that that the
anomalous contraction rate has persisted for the prolonged period of time;
ii) causing an audio signal to be issued by an audio speaker, the audio signal
conveying that
that the anomalous contraction rate has persisted for the prolonged period of
time;
iii) transmitting an electronic message over a computer network to a remote
device, the
electronic message conveying that that the anomalous contraction rate has
persisted for the
prolonged period of time.
These and other aspects and features of the present invention will now become
apparent to those of
ordinary skill in the art upon review of the following description of specific
embodiments of the
invention in conjunction with the accompanying drawings.
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BRIEF DESCRIPTION OF THE DRAWINGS
In the accompanying drawings:
Fig. 1 shows a high-level functional block diagram of a labour monitoring
system
implementing a user interface for displaying uterine contraction infoi __
illation in
accordance with a specific example of implementation of the present invention;
Fig. 2 is a functional block diagram of an apparatus implementing a user
interface for
displaying uterine contraction information in accordance with a specific
example of implementation of the present invention;
Fig. 3 shows a specific example of implementation of a graphical user
interface
implemented by the system shown in figure 1 for displaying uterine contraction
information in accordance with a specific example of implementation of the
invention;
Fig. 4a and 4b show an alternative specific example of implementation of a
graphical
user interface implemented by the system shown in figure 1 for displaying
uterine contraction information in accordance with an alternative specific
example of implementation of the invention;
Fig. 5 shows another alternative specific example of implementation of a
variant of
the graphical user interface implemented by the system shown in figure 1 for
displaying uterine contraction information in accordance with another specific
example of implementation of the invention;
Fig. 6a and 6b are flow diagrams of a process for displaying uterine
contraction
information in accordance with a specific example of implementation of the
present invention;
Fig. 7a and 7b are graphical representations of contraction signals in
accordance with
non-limiting examples of implementation of the present invention;
Fig. 8 is a block diagram of an apparatus for providing uterine contraction
information
in accordance with a specific example of implementation of the present
invention;
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Fig. 9 is a high level conceptual block diagram of a program element for
implementing a graphical user interface of the type shown in either one of
figures 3, 4a, 4b and 5 in accordance with a specific example of
implementation
of the present invention;
Fig. 10 shows a functional block diagram of a client-server system for
providing
uterine contraction information in accordance in accordance with an
alternative
specific non-limiting example of implementation of the present invention.
Other aspects and features of the present invention will become apparent to
those
ordinarily skilled in the art upon review of the following description of
specific
embodiments of the invention in conjunction with the accompanying figures.
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DETAILED DESCRIPTION
With reference to Fig. 1, there is shown a configuration of a labour
monitoring system 150
comprising a uterine activity sensor 120, a user input device 118, an
apparatus 100 implementing a
user interface for displaying uterine contraction information and a display
unit 114.
In accordance with a specific implementation, the sensor 120 for monitoring
uterine activity samples
the contraction pattern at a certain pre-determined frequency to generate a
signal indicative of
uterine activity. The resulting signal, herein referred to as a contraction
signal, conveys information
related to the occurrence of uterine contractions over time. More
specifically, the contraction signal
conveys information on the occurrence of contraction events. Broadly stated, a
contraction event
refers to a continuous time period during which the uterine muscle of an
obstetrics patient is
tightening. During labour, contraction events are interleaved with relaxation
periods during which
the uterine muscle ceases to contract or contracts to a lesser extent. The
contraction signal may be a
continuous signal conveying contraction intensity information or may be
comprised of unitary signal
events where a signal event is generated when a contraction event is detected.
Typically, when the
contraction signal is comprised of unitary signal events, a signal event is
generated when the onset
of a contraction event is detected. Sensors for monitoring uterine activity
are well known in the art
to which this invention pertains and any suitable sensor may be used in
practical implementations.
Alternatively, certain embodiments of the labour monitoring system 150 may
omit the sensor 120
and instead make use of a user-controlled input for generating the contraction
signal. The user-
controlled input allows a user to provide over time information signalling the
onset of a contraction
event such as to convey information associated to contraction activity over
time. Such a user-
controlled input may be in the form of a manually controlled actuator that can
be activated by
depressing a
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button when the obstetrics patient senses the onset of a contraction or in any
other
suitable configuration allowing a user to signal the onset of contraction
events over
time. Although the user controlling the actuator may be the expectant mother,
it will
most likely be a person other than the expectant mother, such as the expectant
father
or a nurse for example, since the expectant mother will most likely have other
concerns during labour. In such an alternative embodiment, the contraction
signal is
comprised of unitary signal events. It will be readily appreciated that such a
configuration may be somewhat inconvenient in practice since it would require
that
the user diligently enter contraction information. Consequently, although this
alternative implementation has been presented for the purpose of completeness
and as
an alternative example of implementation, it will be readily appreciated that
using a
sensor 120 for monitoring uterine activity will be preferred in practical
implementations of the invention.
The apparatus 100 is for implementing a graphical user interface module for
displaying uterine contraction information. The graphical user interface
module
displays first information conveying a rate of uterine contractions derived at
least in
part on the basis of at least a portion of the contraction signal. The
graphical user
interface module also displays, concurrently with the first information,
second
information conveying a threshold rate of uterine contractions. The graphical
user
interface module selectively causes an alarm event based at least in part on a
rate of
uterine contractions conveyed by the first information and the threshold rate
of uterine
contractions. The apparatus 100 also releases a signal for causing the display
unit 114
to display the graphical user interface module. Optionally, the apparatus is
further
adapted for releasing signals to a data output module 130 for causing the
latter to
convey information associated to labour progression to a user of the labour
monitoring system 150. Specific examples of implementation of the apparatus
100
and of the graphical user interface module will be described later on in the
specification.
The user input device 118 is for receiving data from a user of the system. The
user
input device 118 may be used, for example, to enter information associated
with the
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obstetrics patient and/or to manipulate the information displayed by the user
interface implemented
by the apparatus 100. Optionally still, the user input device 118 may be used
to enter contraction
medication information conveying information associated to administration of
contraction inducing
medication to the obstetrics patient. The contraction medication information
may indicate whether
contraction-inducing medication was administered and, optionally, the dosage
of the contraction
inducing medication that was administered. Since, typically, contraction-
inducing medication is
administered continuously over time and not as a one shot dose, the
contraction medication
information conveys the dosage of the contraction inducing medication
administered over time.
The user input device 118 includes any one or a combination of the following:
keyboard, pointing
device, touch sensitive surface, keypad or speech recognition unit. Certain
embodiments of the
labour monitoring system 150 may omit the user input device 118 in alternative
implementations of
the invention.
Optionally, as shown in figure 1, the labour monitoring system 150 may further
include a fetal heart
rate sensor 110. The fetal heart rate sensor 110 is for detecting a fetal
heart rate of a fetus in-utero,
also referred to as a fetus in the womb. The fetal heart rate sensor 110
samples the fetal heart rate at
a certain pre-determined frequency to generate the signal indicative of the
fetal heart rate. Fetal
heart rate sensors are well known in the art to which this invention pertains
and any suitable sensor
for detecting a fetal heart rate may be used in alternative implementations of
the invention and as
such will not be described further here.
Optionally still, the labour monitoring system 150 may include other sensors
(not shown) for
measuring labour progress and the fetus' tolerance to labour. Such sensors may
include for
example:
- a sensor for measuring the maternal oxygen saturation
- a sensor for measuring the fetal oxygen saturation
- a sensor for measuring maternal blood pressure
- a sensor for measuring and analysing the fetal electrocardiogram
Such sensors are not critical to the invention and therefore will not be
described further here.
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The display unit 114 is in communication with the apparatus 100 and receives a
signal causing the
display unit 114 to display a graphical user interface module implemented by
apparatus 100. The
display unit 114 may be in the form of a display screen, a printer or any
other suitable device for
conveying to the physician or other health care professional uterine
contraction information
associated to an obstetrics patient.
Optionally, the labour monitoring system 150 may further include a data output
module 130. The
data output module 130 is in communication with the apparatus 100 and is
suitable for receiving
signals generated by the apparatus 100. In a first specific example of
implementation, the data
output module 130 includes an audio module for releasing audio signals on the
basis of signals
received from the apparatus 100. In a second specific example of
implementation, the data output
module 130 includes a data communication entity suitable for transmitting
messages to remote
devices causing the latter to convey to a user of the labour monitoring system
150 information
associated to labour progression. Examples of remote devices include, without
being limited to,
PDAs, telephones, pagers and computing terminals.
A specific practical implementation of the labour monitoring system 150 may
implement the
graphical user interface module for displaying uterine contraction information
as a stand-alone
component or alternatively as part of a more complete labour monitoring system
including a
plurality of modules for monitoring various aspects of labour progression.
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Apparatus 100
A specific example of implementation of apparatus 100 will now be described
with
reference to figure 2. The apparatus 100 includes an input 202 (labelled as
first input
in the figure), a processing unit 206 and an output 208. The first input 202
is for
receiving a contraction signal from the uterine activity sensor 120 (shown in
figure 1)
conveying information related to occurrences of uterine contractions over
time. The
processing unit 206 is in communication with the first input 202 and
implements a
graphical user interface module for displaying uterine contraction
information. The
output 208 is for releasing a signal for causing the display unit 114 (shown
in figure
1) to display the graphical user interface module implemented by processing
unit 206.
Optionally, as shown in figure 2, the apparatus further includes a second
input 216 for
receiving data from a user through input device 118 (shown in figure 1).
Optionally
still, the apparatus further includes a data interface 210 for exchanging
signals with a
data output module 130 (shown in figure 1) for causing the latter to convey
information associated to labour progression to a user of the labour
monitoring system
150 (shown in figure 1).
Optionally, the apparatus further includes an additional input (not shown in
the
figures) for receiving fetal heart rate information. The fetal heart rate
information
may including a fetal heart rate signal as generated by fetal heart rate
sensor (110) or,
alternatively, may include information conveying a level of risk associated
with the
fetus, the level of risk being derived on the basis of a fetal heart rate
signal. Where
the fetal heart rate information includes a fetal heart rate signal, the
apparatus 100 is
adapted for processing the signal to determine a level of risk associated with
the fetal
heart rate signal. Any suitable method for assessing a level of risk on the
basis of a
fetal heart rate signal may be used. For example, the level of risk may be
based on the
frequency of the fetal heart rate, whether it is too high or too low for a
certain period
of time. Alternatively, the level of risk may be based on other known methods.
A
non-limiting example of a method for providing an indication of the level of
risk is
described in U.S. patent no. 7,113,819, entitled "Method and apparatus for
monitoring
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the condition of a fetus", issued on September 26, 2006 to E. Hamilton et al.
and assigned to LMS
Medical Systems Ltd. Other suitable methods for assessing a level of risk on
the basis of a fetal
heart rate signal may be used in alternative implementations of the invention.
The graphical user interface module will now be described in greater detail.
The graphical user interface module receives the contraction signal conveying
information related to
uterine contractions over time and displays first and second information. The
first information
conveys a rate of uterine contractions which is derived at least in part on
the basis of at least a
portion of the contraction signal received at input 202. The second
information conveys a threshold
rate of uterine contractions. The threshold rate of uterine contractions
defines boundaries of safe
care and may be set in accordance best practices or in accordance with
hospital/care-giver facility
policy. Although the present description refers to a single threshold rate of
uterine contraction, it
will be readily apparent that embodiments including multiple thresholds of
uterine contractions,
each threshold being associated with a respective degree of risk to the
obstetrics patient, may be
used in alternative implementations of the present invention.
The specific manner in which the information can be displayed to a user of the
system 150 by the
graphical user interface module may vary from one implementation to the other.
Specific non-
limiting examples of implementation of a graphical user interface module are
shown in figures 3, 4a
and 4b.
A first specific example of implementation of the graphical user interface
module is shown in figure
3 of the drawings. In this specific implementation, the first information
includes a first tracing 504
conveying rates of uterine contractions over time and the second information
includes a second
tracing 502 conveying a threshold rate of uterine contractions. The first
tracing 504 and the second
tracing 502 are displayed in a same viewing window 500. The first tracing 504
conveys a running
average of the number of contraction events derived from the contraction
signal receiving at input
202 (shown in figure 2). In the non-limiting example shown in figure 3, the
first tracing conveys the
number of contraction events over the previous 10 minutes. The threshold rate
of uterine
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contractions illustrated by the second tracing 502 marks a boundary between
uterine contraction
rates considered to be within safe boundaries (contraction rates falling below
the second tracing 502)
and contraction rates considered as being associated to riskier situations
(contraction rates falling
above the second tracing 502). In the example depicted, the second tracing 502
is depicted by a
dotted line positioned along a contraction rate of 5 contractions/10 minutes,
corresponding to a
common definition of uterine hypercontractility. It will be readily
appreciated that other suitable
threshold rates of uterine contractions may be used in alternative
implementations of the invention.
Advantageously, the implementation depicted in figure 3 allows the clinical
staff to readily observe
the trend in contraction rates over time for a given obstetrics patient as
conveyed by the first tracing
504. The first and second tracings 504 502 displayed in a same viewing window
500 allow to
clinical staff to readily ascertain the contraction rate and variations
thereof with respect to the
threshold contraction rate over an extended time period. This allows the
clinical staff to have a more
complete view of the history of the contraction rate since labour onset, or at
least since the clinical
staff was monitoring the labour. For example, this allows determining whether
the contraction rate
is consistently above the threshold rate or whether it was merely a temporary
increase in contraction
rate and was induced either through the administration of medication or other
method. Also, in
situations where the contraction rate exceeds the threshold rate, the
implementation depicted in
figure 3 allows the clinical staff to observe by how much the contraction rate
exceeds the threshold
rate. This may allow the clinical staff to ascertain more easily whether
the excess is minor,
indicating perhaps a low level risk, or whether it is significant, requiring a
quicker intervention.
A second specific example of implementation of the graphical user interface
module is shown in
figures 4a and 4b of the drawings. In the specific implementation shown in
figure 4a, the first
information includes a first alphanumeric element 602a conveying a rate of
uterine contractions
associated to an obstetrics patient and the second information includes a
second alphanumeric
element 604 conveying a threshold rate of uterine contractions. The first
alphanumeric element
602a and the second alphanumeric element 604 are displayed concurrently in
viewing window 600a.
In this specific implementation, the first alphanumeric element 602a reflects
the current contraction
rate derived on the basis of a contraction signal received at input 202 (shown
in figure 2). In the
non-limiting example shown in figure 4a, the first alphanumeric element 602a
conveys the number
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of contraction events over the previous 10 minutes.
The first alphanumeric element 602a is
continuously, or periodically, updated over time on the basis of the
contraction signal receiving at
input 202 (shown in figure 2). The threshold rate of uterine contractions
conveyed by the second
alphanumeric element 604 indicates the boundary between uterine contraction
rates considered to be
within safe boundaries and contraction rates considered as being associated to
riskier situations. In
the example depicted, the second alphanumeric element 604 conveys a
contraction rate of 5
contractions/10 minutes, corresponding to a common definition of uterine
hypercontractility. It
will be readily appreciated that other suitable threshold rates of uterine
contractions may be used in
alternative implementations of the invention.
Advantageously, the implementation depicted in figures 4a and 4ballows the
clinical staff to also
readily appreciate whether current the contraction rate is within the
boundaries of safe care as
conveyed by the second alphanumeric element 604.
Optionally, as depicted in the specific examples shown in figures 4a and 4b,
the graphical user
interface module also displays an alphanumeric indicator 610a in the form of a
rating for conveying
to the user of the graphical user interface module an indication of whether
the current contraction
rate is within the boundaries of safe care. In the example depicted in figure
4a, the first
alphanumeric element 602a conveys a contraction rate of 4 contractions/10
minutes which is below
the 5 contractions/10 minutes threshold conveyed by the second alphanumeric
element 604. In this
case the alphanumeric indicator 610a indicates the message "OK or SAFE"
conveying that the
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current contraction rate is within an acceptable range. In figure 4b, the same
example
of implementation of the graphical user interface module as that shown in
figure 4a is
shown but with a different value of the current contraction rate. In this
example, in
the viewing window 600b, the first alphanumeric element 602b conveys a
contraction
rate of 7 contractions/10 minutes, which is above the 5 contractions/10
minutes
threshold conveyed by the second alphanumeric element 604. In this
case the
alphanumeric indicator 610b indicates the message "ELEVATED RISK" conveying
that the current contraction rate is not within an acceptable range. In
alternative
examples of implementation, the alphanumeric indicator 610b may be adapted for
displaying graded risk levels such as for example "mildly elevated",
"moderately
elevated" and "critically elevated" for example.
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Alarm Events
The graphical user interface module is adapted for selectively causing an
alarm event
based at least in part on a rate of uterine contractions and the threshold
rate of uterine
contractions. In a specific example of implementation, the alaiin event is for
alerting
the clinical staff making use of the system of an occurrence of a potentially
problematic situation during labour associated to the occurrence of
contractions.
The alarm event may be triggered in a number of situations and may be based on
rates
of uterine contractions and the threshold rate of uterine contractions and
optionally on
the basis of either one or both of contraction medication information and
fetal heart
rate information. Examples of the manners in which an alarm event may be
selectively caused will be described later on in the specification.
An alarm event, in accordance with a specific example of implementation of the
invention, may include one or more components for communicating information to
a
user of the graphical user interface module.
In a first specific implementation, the alarm event includes displaying a
visual
indicator to convey to a user of the graphical user interface module an
occurrence of a
potentially problematic situation during labour. The visual indicator may be
displayed as part of the graphical user interface module or in a separate
display at a
remote location. Any suitable type of visual indicator may be used. Examples
of
visual indicators that may be used include, without being limited to:
)> Variations in color. For example, a color scheme may be established whereby
certain colors are associated with varying levels of risk. Portions of the
graphical
user interface may turn a certain color associated with a high level of risk
when,
for example, the rate of uterine contractions falls outside a limit set by the
threshold rate of uterine contractions. In the non-limiting example depicted
in
figure 3, the portions of the first tracing 504 exceeding the threshold
contraction
rate (illustrated by reference numeral 508 in the figure) are displayed in a
different
colour or colour intensity that the remaining portions of the first tracing
504.
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Alternatively, the entire display window or a portion of the window may be
displayed may turn a certain color associated with a high level of risk based
at
least in part on a rate of uterine contractions conveyed by the first
inforniation and
the threshold rate of uterine contractions. A non-limiting example of a color
scheme is green = normal; yellow: intermediate risk level; red: high level of
risk
however any suitable color scheme may be used.
D Variation in display intensity of the viewing window. For example, flashing
or
blinking of the viewing window may be used as a visual indicator to draw the
attention of the user;
D Variation in the size or position of the viewing window. For example, the
viewing window may be made to appear more prominently on the display unit or
at a location that is more likely to draw the attention of the clinical staff;
D Displaying a message prompting/alerting the clinical staff For example, in
figure
4b, an alphanumeric message 610 is displayed as "ELEVATED RISK" to convey
that the current contraction rate conveyed by the first alphanumeric element
602b
has exceeded the threshold rate of uterine contractions conveyed by the second
alphanumeric element 604. In this example, when the current contraction rate
falls below the threshold rate of uterine contractions, either no message may
be
displayed or a message conveying that the current contraction rate is within
the
limit set by the threshold rate of uterine contractions as shown in figure 4a.
In a second specific implementation, the alarm event includes causing an audio
signal
to be issued, alone or in combination with a visual indicator, to draw
attention of a
user of the graphical user interface module. In this second specific
implementation,
the processing unit 206 (shown in figure 2) releases a signal at the data
interface 210
for causing an audio unit (not shown in the figures) to issue an audio signal.
The
audio unit may be connected directly to the data interface 210 through either
a wire-
line link or a wireless link. Alternatively, the audio unit may be in
communication
with the data interface 210 over a network. Alternatively still, the audio
unit may be
an integral part of apparatus 100.
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In a third specific implementation, the alarm event includes causing a message
signal
to be transmitted to a remote device. The remote device may be, for example, a
PDA,
telephone, pager or a remote computing terminal. Other suitable types of
remote
devices may also be envisaged in other specific implementations of the present
invention. In this third specific implementation, the processing unit 206
(shown in
figure 2) releases a signal at the data interface 210 for causing a message
signal to be
transmitted to the remote device. The remote device may be connected directly
to the
data interface 210 though either a wire-line link or a wireless link.
Alternative, the
remote device may be in communication with the data interface 210 over a
network.
In a first practical example of interaction, the remote device is a PDA
assigned to a
doctor responsible for overseeing deliveries in a hospital. At least in part
on a rate of
uterine contractions conveyed by the first information and the threshold rate
of uterine
contractions, the graphical user interface module selectively sends a message
through
the data interface 210 and over a network to the PDA of the doctor to alert
that doctor.
The message may include any suitable useful information including, but not
limited
to, the name of the obstetrics patient, the location of the patient, the
contraction rate,
contraction medication information, fetal heart rate information, labour
progression
information (duration of labour, time since admission to hospital) and medical
history.
Optionally, the message may also enable the PDA of the doctor to display all
or part
of the user interface module described in the present application. For
example, the
message may enable the PDA of the doctor to display a user interface of the
type
depicted in figures 3, 4a and 4b. Alternatively, the message may only indicate
that a
certain patient requires closer monitoring of her contraction rate. The
specific format
of the message is not critical to the invention and as such will not be
discussed further
here.
In second practical example of interaction, the remote device is a remote
computing
terminal located at a centralised nursing station in a hospital birthing
centre. At least
in part on a rate of uterine contractions conveyed by the first information
and the
threshold rate of uterine contractions, the graphical user interface module
selectively
causes a message to be sent to the remote computing terminal. Advantageously,
by
allowing a message to be transmitted to a remote device, the clinical staff
need not be
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located near the patient or in proximity to the patient to be alerted to
potentially
problematic situations. In
addition, the clinical staff need not be expressly
monitoring the progression of the contraction rate to be alerted to an unsafe
condition
for the contraction rate.
The Process
An exemplary embodiment of the process implemented by the graphical user
interface
will now be described with reference to figures 6a and 6b.
With reference to figure 6a, at step 300, the contraction signal is received
by the
graphical user interface module.
At step 302, the graphical user interface module computes a contraction rate
on the
basis of the contraction signal received at step 300.
The specific manner in which the contraction rate is computed will depend on
the
format of the contraction signal. In a first specific example, the contraction
signal is a
continuous signal conveying the intensity of the uterine contractions over
time. A
non-limiting graphical representation of such a continuous signal is depicted
in figure
7a for the purpose of illustration. In such an implementation, the graphical
user
interface module is operative for processing the contraction signal to detect
the
occurrence of contraction events in the contraction signal. Any
suitable pattern
recognition technique may be used for identifying the occurrence of
contraction
events. Such techniques are well known in the art of signal processing and as
such
will not be described further here. Once the occurrence of contraction events
has
been detected, the contraction rate can be computed.
In a second specific example, the contraction signal received at input 202 is
comprised of unitary signal events where a signal event is generated when a
contraction event is detected. A non-limiting graphical representation of such
a
continuous signal is depicted in figure 7b for the purpose of illustration. In
such an
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implementation, pattern recognition techniques are not required since the
presence of contraction
events is already conveyed by the contraction signal.
In a specific implementation, the graphical user interface module computes a
rate of contraction
events in the contraction signal for a certain time segment. The rate of
contraction events in the
contraction signal may be computed in a number of suitable manners.
In a specific example, a current contraction rate is equal to the number of
contraction events
detected in the contraction signal over the last time duration T. The duration
T may be any suitable
time duration. In a non-limiting example, the duration T is 10-15 minutes and
the current
contraction rate is the number of contraction events in the contraction signal
that occurred over the
previous 10-15 minutes. Most clinical guidelines describe the desirable
contraction frequency based
on an observation period of 10-15 minutes. It will be readily apparent to the
person skilled in the art
that the time duration T may have a duration different than 10-15 minutes.
Moreover, the time
duration T may be a configurable parameter of the graphical user interface
module implemented by
processing unit 206 in alternative implementations of the invention.
Typically, the duration T will
be selected to be a time duration sufficiently long so that a few contraction
events are likely to occur
during active labour but sufficiently short so that the contraction rate for a
given time duration T is
representative of the progression of the contraction rate during active
labour. It will be readily
apparent to the person skilled in the art that a very lengthy time duration,
let us say 3 hours, does not
provide useful information as to whether the contraction rate is within
reasonable boundaries.
Similarly, a very short time duration, let us say 2 minutes, also does not
provide any useful
information as to whether the contraction rate is within reasonable
boundaries.
It will be readily apparent to the person skilled in the art, in light of the
present description, that
other well-known techniques for computing a contraction rate on the basis of a
contraction signal
may be used in alternative
implementations of the invention.
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At step 304, the graphical user interface module implemented by the processing
unit
206 displays first information conveying the rate of uterine contractions
derived at
step 302. At step 306, the graphical user interface module implemented by the
processing unit 206 displays concurrently with the first information, second
information conveying a threshold rate of uterine contractions. Specific non-
limiting
examples of formats for the first information and second information were
described
with reference to figures 3, 4a and 4b of the drawings.
At step 308, the graphical user interface module determines, at least in part
on the
basis of the computed contraction rate and the threshold contraction rate,
whether an
alarm event should be caused.
As will become apparent to the person skilled in the art in light of the
present
specification, different conditions may bring the graphical user interface
module to
cause an alarm event.
In a first specific example of implementation, an alarm event is triggered
depending
on the specific circumstances conveyed by the computed contraction rate and
the
threshold contraction rate alone.
In a second specific example of implementation, an alarm event is triggered
depending on the specific circumstances conveyed by the computed contraction
rate
and the threshold contraction rate in combination with other factors. Such
other
factors may include, without being limited to, contraction medication
information and
fetal heart rate information.
In either one of the above described specific examples of implementation, the
conditions for causing an alarm event may be determined on the basis of a
hospital
policy or in accordance with best recognised practices in health care.
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In a specific example of implementation, step 308 shown in figure 6a includes
multiple sub-steps for determining whether an alarm event should be caused.
Figure
6b shows a non-limiting example of implementation of process step 308.
As depicted, at step 350 the graphical user interface module determines
whether the
computed contraction rate exceeds the limit set by threshold contraction rate.
If step
350 is answered in the negative and the computed contraction rate does not
exceed the
limit set by threshold contraction rate, step 308 determines that no alarm
should be
caused and the graphical user interface proceeds to step 300.
If step 350 is answered in the affirmative and the computed contraction rate
exceeds
the limit set by threshold contraction rate, the graphical user interface
proceeds to step
352 where an additional condition is tested.
At step 352 the graphical user interface module determines whether the
computed
contraction rate has exceeded the limit set by the threshold contraction rate
for a time
duration exceeding a predetermined time duration. This step 352 allows testing
whether the excess of the contraction rate is merely transient of whether it
is
persistent. The predetermined time duration may be established on the basis of
a
hospital policy or, alternatively, on the basis of other clinical guidelines.
If step 352 is answered in the affirmative and the computed contraction rate
exceeds
the limit set by threshold contraction rate for a duration of time exceeding
the
predetermined time duration indicating that the excess of the contraction rate
is
persistent, step 308 determines that an alarm event should be caused and the
graphical
user interface proceeds to step 310.
If step 352 is answered in the negative and the computed contraction rate has
not
exceeded the limit set by threshold contraction rate for a duration of time
exceeding
the predetermined time duration indicating that the excess of the contraction
rate may
be transient, the graphical user interface module proceed to step 356 where an
additional condition is tested.
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At step 356 the graphical user interface module deten-nines whether the
contraction
medication information indicates that contraction inducing medication was
given to
the obstetrics patient. Optionally, step 356 may also evaluate the level (or
dosage) of
contraction inducing medication if any was changed and use that information in
effecting the decision step 356.
If step 356 is answered in the affirmative and the contraction medication
information
indicates that contraction inducing medication was given to the obstetrics
patient, step
308 determines that an alarm event should be caused and the graphical user
interface
proceeds to step 310.
If step 356 is answered in the negative and the contraction medication
information
indicates that contraction inducing medication was not given to the obstetrics
patient,
the graphical user interface module proceed to step 358 where an additional
condition
is tested.
At step 358 the graphical user interface module determines whether the fetal
heart rate
information available indicates a problematic risk level associated with the
baby's
well-being. The fetal heart rate information may include a fetal heart rate
signal or,
alternatively, may include information conveying a level of risk associated
with the
fetus, the level of risk being derived on the basis of a fetal heart rate
signal. In a
specific example of implementation, the fetal heart rate information includes
a fetal
heart rate signal and is received from the fetal heart rate sensor 110 (shown
in figure
1). Where the fetal heart rate information includes a fetal heart rate signal,
step 358
includes processing the signal to detelmine a level of risk associated with
the fetal
heart rate signal. Any suitable method for assessing a level of risk on the
basis of a
fetal heart rate signal may be used. For example, the level of risk may be
based on the
frequency of the fetal heart rate, whether it is too high or too low for a
certain period
of time. Alternatively, the level of risk may be based on other suitable known
methods. A non-limiting example of a method for providing an indication of the
level
of risk is described in U.S. patent no. 7,113,819, entitled "Method and
apparatus for
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monitoring the condition of a fetus", issued on September 26, 2006 to E.
Hamilton et al. and
assigned to LMS Medical Systems Ltd. Other suitable methods for assessing a
level of risk on the
basis of a fetal heart rate signal may be used in alternative implementations
of the invention.
If step 358 is answered in the affirmative and the fetal heart rate
information indicates a problematic
risk level associated with the baby's well-being, step 308 determines that an
alarm event should be
caused and the graphical user interface proceeds to step 310.
If step 358 is answered in the negative and the fetal heart rate information
does no indicates a
problematic risk level associated with the baby's well-being, step 308
determines that no alarm
should be caused and the graphical user interface proceeds to step 300.
In the specific example of implementation shown in figure 6b, steps 352 356
and 358 are optional
steps which may be included or omitted from specific implementations of the
present invention. In
addition, it will be appreciated in light of the present specification that
other suitable manners of
determining whether an alarm event should be caused on the basis of the
computed contraction rate
and the threshold contraction rate may be used in alternative implementations
of the invention. As
such, it should be understood that the example depicted in figure 6b was
presented for the purpose of
illustration only.
Returning now to figure 6a, if step 308 determines that an alarm event should
be caused, the
graphical user interface module proceeds to step 310 where an alarm event is
triggered. Examples of
alarm events were described previously in the specification. The graphical
user interface module
then returns to step 300 where the next segment of the contraction signal is
received and
subsequently processed.
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If step 308 determines that no alarm event should be caused, the graphical
user
interface module returns to step 300 where the next segment of the contraction
signal
is received and subsequently processed.
As can be observed, the process illustrated in figure 6a is an iterative
process whereby
steps 300 to 308 (and selectively step 310 when an alarm event is caused to
occur) are
repeated as time progresses and as new segments of the contraction signal are
received by the apparatus. Over time, the graphical user interface module
processes
the contraction signal to derive a set of contraction rate data elements,
where each
contraction rate data element in the set of contraction rate data elements is
associated
to a segment of the contraction signal. In a non-limiting example, the
graphical user
interface module computes a running average of contractions in the contraction
signal
to derive the set of contraction rate data elements.
Although the exemplary embodiment of the process implemented by the graphical
user interface described with reference to figures 6a and 6b made reference to
a single
alarm event presented in box 310, it will be appreciated that different types
of alarm
events may be caused by the graphical user interface. More specifically,
different
circumstances conveyed by the computed contraction rate, contraction
medication
information, fetal heart rate information and optionally other conditions may
be
associated to respective types of alarm events. Therefore, although the
specification
described causing a given alarm event, it should be understood that different
types of
alarm events may be caused and that the type of alarm event caused may be
conditioned at least in part on the basis of the circumstances conveyed by the
computed contraction rate, (optionally) contraction medication information,
(optionally) fetal heart rate information and optionally other conditions,
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Variant
As a variant, the graphical user interface module is adapted for displaying,
concurrently with the
first information conveying a rate of uterine contractions and the second
information conveying a
threshold rate of uterine contractions, additional information elements
related to labour progression.
Figure 5 of the drawings depicts a non-limiting example of implementation of a
display generated
by the graphical user interface module in accordance with this variant.
As shown, the graphical user interface module displays a first viewing window
570 including a first
tracing 574 conveying rates of uterine contractions over time and a second
tracing 572 conveying a
threshold rate of uterine contractions. The graphical user interface module
also displays a second
viewing window 558 including a tracing 582 conveying a uterine contraction
pattern over time
(TOCO tracing) and a tracing 584 conveying a fetal heart rate pattern over
time. The tracing 582
conveying a uterine contraction pattern over time is derived on the basis of
the contraction signal
received from the uterine activity sensor 120 (shown in figure 1). The tracing
584 conveying a fetal
heart rate pattern over time is derived on the basis of the fetal heart rate
signal received from the
fetal heart rate sensor 110 (also shown in figure 1). Preferably, the first
viewing window 570 and
second viewing window 558 are time-aligned with one another on the display. In
addition, it will be
appreciated that either one of the tracings 584 and 582 may be omitted from
the second viewing
window 558 or that these tracings 584 and 582 may be displayed in separate
viewing windows in
alternative implementations of the invention.
Advantageously, the display of the tracing 584 conveying a fetal heart rate
pattern over time allows
the users of the system to view a representation of the baby's response to the
contraction events.
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The display of the tracing 582 conveying a uterine contraction pattern over
time
allows the users of the system to view a representation of the original
contraction
signal and to assess whether the tracing 574 conveying rates of uterine
contractions
over time accurately reflects the rate of contractions in the original
contraction signal.
This is particularly useful when the contraction signal generated by the
uterine
activity sensor part of the electronic fetal monitor 110 (shown in figure 1)
is a
continuous contraction signal (as opposed to a unitary contraction signal)
since
pattern recognition techniques must be used on such a continuous signal to
determine
the occurrence of a contraction event. These pattern recognition techniques
may
erroneously detect an occurrence of a contraction event or may fail to detect
an
occurrence of a contraction event. Therefore, by presenting the user with the
tracing
582 conveying a uterine contraction pattern over time, that user may adjust
his/her
assessment of the first tracing 574.
In the embodiment depicted, the graphical user interface module also displays
a
control 556 allowing a user to select a portion of the tracings in the first
viewing
window 570 and/or the second viewing window 558. The user is enabled to
manipulate the control 556 by providing signals using user input device 118
(shown
in figure 1).
In a specific implementation, the control 556 includes a selection box having
a
transparent portion superposed upon the first viewing window 570 and the
second
viewing window 558. The portions of the tracings viewable through the
transparent
portion correspond to the selected portions. The control 556 allows the user
to
displace and modify the size of the selection box to select a portion of the
tracings.
Other manners in which portions of a labour progression signal may be selected
are
described in U.S. patent no. 6,907,284 issued to E. Hamilton et al. on June
14, 2005.
In the embodiment depicted, the graphical user interface module also displays
a third
viewing window 550 including a tracing 552 conveying a fetal heart rate
pattern over
time and a tracing 554 conveying a uterine contraction pattern over time (TOCO
tracing). The tracing 552 in the third viewing window 550 conveying a fetal
heart
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rate pattern over time corresponds to the selected portion of the tracing 584
in the second viewing
window 558 and is a zoomed-in view of that selected portion. The tracing 554
in the third viewing
window 550 conveying a conveying a uterine contraction pattern over time (TOCO
tracing)
corresponds to the selected portion of the tracing 582 in the second viewing
window 558 and is a
zoomed-in view of that selected portion. In addition, it will be appreciated
that either one of the
tracings 552 and 554 may be omitted from the third viewing window 550 or that
these tracings 552
and 554 may be displayed in separate viewing windows in alternative
implementations of the
invention.
Advantageously, by displaying zoomed-in views of the selected portions of the
tracings 582 and
584, a user will be able to better view responses of the fetal heart rate to
individual contraction
events (amount of variability size and type of deceleration) and will be able
to better assess the
intensity and duration of a given contraction event.
In the embodiment depicted, the graphical user interface module also displays
a fourth viewing
window 560 including a tracing 561 conveying information associated to
administration of
contraction inducing medication to the obstetrics patient. The tracing 561 is
derived on the basis of
contraction medication information received by apparatus 100 (shown in figure
1). The contraction
medication information may indicate whether contraction-inducing medication
was administered
and, optionally, a dosage of the contraction inducing medication administered.
Since, typically,
contraction inducing medication is administered continuously over time and not
as a one shot dose,
the contraction medication information when conveying a dosage of the
contraction inducing
medication administered may convey such dosage over time. In a first specific
example of
implementation, the contraction medication information is provided by the
clinical staff using user-
input device 118. In this first implementation, the clinical staff preferably
entered the level (or
dosage) of the contraction-inducing medication administered and updates that
information when the
dosage is modified. In a second specific example of implementation, the
contraction medication
information is provided automatically by a device, typically in the form of
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an electronic pump, designed to measure the dosage of medication provided to
the
obstetrics patient and provide that information over time to apparatus 100. In
the
embodiment depicted in figure 5, the tracing 561 shows the level of medication
administered over time to stimulate contractions. It will be appreciated by
the person
skilled in the art of obstetrics that the tracing 561 is not representative of
an actual
(real life) situation and that the levels of medication conveyed by tracing
561 are
presented here for the purpose of illustration only.
Advantageously, the tracing 561 allows the clinical staff to readily view
whether
contraction inducing medication was administered to the obstetrics patient
being
monitored (and optionally the amount of contraction inducing medication which
was
administered).
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Specific Physical Implementation
Those skilled in the art should appreciate that in some embodiments of the
invention,
all or part of the functionality previously described herein with respect to
the
apparatus for implementing a user interface for displaying uterine contraction
information may be implemented as pre-programmed hardware or firmware elements
(e.g., application specific integrated circuits (ASICs), electrically erasable
programmable read-only memories (EEPROMs), etc.), or other related components.
In other embodiments of the invention, all or part of the functionality
previously
described herein with respect to the apparatus for implementing a user
interface for
displaying uterine contraction information may be implemented as software
consisting of a series of instructions for execution by a computing unit. The
series of
instructions could be stored on a medium which is fixed, tangible and readable
directly by the computing unit, (e.g., removable diskette, CD-ROM, ROM, PROM,
EPROM or fixed disk), or the instructions could be stored remotely but
transmittable
to the computing unit via a modem or other interface device (e.g., a
communications
adapter) connected to a network over a transmission medium. The transmission
medium may be either a tangible medium (e.g., optical or analog communications
lines) or a medium implemented using wireless techniques (e.g., microwave,
infrared
or other transmission schemes).
The apparatus implementing a user interface for displaying uterine contraction
information may be configured as a computing unit of the type depicted in
figure 8,
including a processing unit 702 and a memory 704 connected by a communication
bus 708. The memory 704 includes data 710 and program instructions 706. In a
specific example of implementation, the data 710 stored in memory 704 includes
one
or more threshold contraction rates. The processing unit 702 is adapted to
process the
data 710 and the program instructions 706 in order to implement the functional
blocks
described in the specification and depicted in the drawings. In a non-limiting
implementation, the program instructions 706 implement the functionality of
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,
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processing unit 206 described above. The computing unit 702 may also comprise
a number of
interfaces 712 714 716 for receiving or sending data elements to external
devices. For example,
interface 712 is used for receiving data streams indicative of uterine
activity and interface 714 is
used for receiving a control signals and/or information from the user.
Interface 716 is for releasing a
signal causing a display unit to display the user interface generated by the
program instructions 706.
Optionally, the computing unit 702 may include additional interfaces (not
shown) for receiving
information from additional sensors such as, for example, a fetal heart rate
sensor.
It will be appreciated that the system for implementing a user interface for
displaying uterine
contraction information may also be of a distributed nature where the
contraction signal is collected
at one location by a uterine activity sensor and transmitted over a network to
a server unit
implementing the graphical user interface. The server unit may then transmit a
signal for causing a
display unit to display the graphical user interface. The display unit may be
located in the same
location as the uterine activity sensor, in the same location as the server
unit or in yet another
location. Figure 10 illustrates a network-based client-server system 900 for
displaying uterine
contraction information. The client-server system 900 includes a plurality of
client systems 912 914
916 918 connected to a server system 910 through network 920. The
communication links 950
between the client systems 912 914 916 918 and the server system 910 can be
metallic conductors,
optical fibers or wireless, in specific practical implementations of the
invention. The network 920
may be any suitable network including but not limited to a global public
network such as the
Intranet, a private network and a wireless network. The server 910 may be
adapted to process and
issue signals to display multiple heart rate signals originating from multiple
sensors 926 928
concurrently using suitable methods known in the computer related arts.
The server system 910 includes a program element 960 for execution by a CPU.
Program element
960 implements similar functionality as program instructions 706 (shown in
figure 8) and includes
the necessary networking functionality to allow the
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server system 910 to communicate with the client systems 912 914 916 918 over
network 920. In a non-limiting implementation, program element 960 includes a
number of program element components, each program element components
implementing a respective portion of the functionality of the user interface
for
displaying uterine contraction information.
Figure 9 shows a non-limiting example of the architecture of program element
960 at
the server system. As shown, the program element 960 includes three program
element components:
1. the first program element component 800 is executed on server system 910
and is for receiving a contraction signal conveying information related to
occurrences of uterine contractions over time;
2. the second program element component 802 is executed on server system 910
and is for sending messages to a client system, say client system 914, for
causing client system 914 to:
¨ display first information conveying a rate of uterine contractions, the
first
information being derived at least in part on the basis of at least a portion
of the contraction signal; and
¨ display, concurrently with the first information, second information
conveying a threshold rate of uterine contractions;
3. the third program element component 804 is executed on server system 910
and is for selectively sending messages to client system 914 for causing an
alarm event based at least in part on a rate of uterine contractions conveyed
by
said first information and the threshold rate of uterine contractions.
Alternatively, the third program element component 804 is executed on server
system 910 and is for selectively sending messages to a client system distinct
from the client system 914 for causing an alarm event at the distinct client
system. The messages for causing an alarm event may include alarm program
elements for execution at the client system, the alarm program elements
implementing the alarm events when executed at the client system.
Alternatively, alarm program elements for implementing the alarm events are
stored at the client system and the messages for causing an alarm event
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transmitted from the server system 910 include instructions for causing the
alarm program elements
at the client system to be executed.
Those skilled in the art should further appreciate that the program
instructions 706 and 960 may be
written in a number of programming languages for use with many computer
architectures or
operating systems. For example, some embodiments may be implemented in a
procedural
programming language (e.g., "C") or an object oriented programming language
(e.g., "C++" or
"JAVA").
Although the present invention has been described in considerable detail with
reference to certain
preferred embodiments thereof, variations and refinements are possible. The
scope of the invention
is defined more particularly by the appended claims.
