Note: Descriptions are shown in the official language in which they were submitted.
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PORTABLE THERAPEUTIC COOLING SYSTEM
BACKGROUND OF THE INVENTION
Field of the Invention
[0002] The present invention relates generally to a cooling system and more
particularly, but not by way of limitation, to a portable therapeutic cooling
system utilizing
gas that provides a mild hypothermic effect adapted to be used immediately or
as soon as
possible following a traumatic event.
Description of the Related Art
[0003] There are circumstances in which it may be desirable to positively cool
a
patient as part of clinical treatment. Benefits may arise by subjecting
patients who have
suffered a stroke or cardiac arrest, or other significant or life threatening
health event, to mild
hypothermia, e.g. a temperature in the range of 32 to 34 C for a period of
more than about 1
hour after the cardiac arrest. Because the period of time from the significant
or life
threatening health event to when the patient's body may be treated may be
great due to
extraneous circumstances, such as transportation to a hospital, it is
suggested that such
treatment begin as soon as possible.
[0004] Temperature is an important variable in determining the amount of
neural
damage resulting from an ischemic attack (Dietrich et al, 1990). Clinically,
temperature is
now deemed a significant, independent risk factor for stroke (Reith et al,
1996), as well as a
contributing risk factor to other risk factors for stroke such as
hypertension, cigarette
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smoking, atrial fibrillation, diabetes, and transient ischemic attacks etc.
Therapeutically, the
implementation of mild hypothermia (34-36 C) to stroke and head trauma
patients is
advocated as beneficial based on clinical studies (ICammersgaard et al, 2000;
Schwab et al,
1997) and animal experiments indicating long term neural and behavioral
benefits (Corbett &
Thornhill, 2000; Colbourne & Corbett, 1994).
[0005] Clinically, whole body cooling of stroke patients has been tested with
forced
air-cooling with the Bair Hugger wrap and anesthetics (Kammersgaard et al,
2000) or with
cooling from fans and alcohol washes (Schwab et al, 1997). Pethidine
anesthetic is given to
prevent shivering activation. More regionalized head cooling of head trauma
and stroke
patients has been attempted. Cooling helmets (previously cooled or having
cooled water or
air circulating through them) attempt to decrease brain temperature via
conductive changes
through the skull (Klatz & Goldman, 1995 in U.S. Pat. No. 5,913,885; Gunn &
Gunn 1998 in
PCT Patent Application W098/56310). Cooling pillows for the head and neck
region have
also been devised to decrease the body temperature of the patient (Tsutomu &
Koji, 1998 in
Japanese Patent Publication 09-072152; Katsumitsu & Shinichi, 2000 in Japanese
Patent
Publication 10-250455). These devices are often bulky and require specialized
knowledge of
the device in order to operate the device effectively.
[0006] Review of exemplary prior devices indicates that there is a need for a
device
or system that cools the entire body in conjunction with a temperature
monitoring system so
as to regulate the cooling effect. There is a need for a device that can be
quickly applied to
the patient shortly after a significant or life threatening health event. Such
a device is
particularly necessary in a pre-hospital setting, such as during transport in
an emergency
vehicle.
[0007] Further, prior devices are relatively bulky and uncomfortable. In the
pre-
hospital setting, for example, when a subject is being transported to a
hospital after injury,
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there is a need for a device that is comfortable and respectful of the
subject's physical
condition. In the case of injury to the brain induced by stroke, or in the
case of cardiac arrest,
a subject may be transported to a hospital over a long distance. Many such
subjects are
elderly and would find it uncomfortable, traumatic or even undignified to be
encased in such
devices as are known. Particularly, bulky helmet-like devices with circulating
fluids or large
cooling inserts are inappropriate for this reason. Further, the sheer size of
the known devices
prohibit them from becoming a standard item kept in an emergency vehicle, or
in any other
pre-hospital setting having a limited amount of storage space. Prior devices
further rely on
infusions of cold saline, which suffers from a lack of temperature control
during application
of the infusion.
[0008] There is a need to have a simple, body-enclosing device that may be
utilized
by emergency medical technicians, health-service personnel, or in the
patient's immediate
area (e.g. home) that can cool the body to prevent damage to critical portions
of the body and
minimize any after-effects of such traumatic health events prior to reaching a
hospital.
BRIEF SUMMARY OF THE INVENTION
[0009] The present invention fulfills these and other needs through the
development
of a portable therapeutic cooling system that utilizes convective cooling and
re-circulated air
to efficiently, safely, and effectively cool the head and body of the patient,
clothed or not,
immediately after a significant or life threatening health event, such as a
cardiac arrest or
stroke.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0010] A more complete understanding of the method and apparatus of the
present
invention may be obtained by reference to the following Detailed Description
of the
Invention, with like reference numerals denoting like elements, when taken in
conjunction
with the accompanying Drawings wherein:
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[0011] FIGURE 1 is a top partial cutaway view of a portable therapeutic
cooling
system is shown according to one embodiment of the present invention;
[0012] FIGURE 2 is a top-plan view of a portable therapeutic cooling system in
accordance with another embodiment of the present invention;
[0013j FIGURE 3 is a schematic diagram of a portable therapeutic cooling
system
according to one embodiment of the present invention;
[0014] FIGURE 4 is another schematic diagram of a portable therapeutic cooling
system according to one embodiment of the present invention;
[0015] FIGURE 5 is another schematic diagram of an alternate cooling system
used
with a portable therapeutic system according to one embodiment of the present
invention;
[0016] FIGURE 6 is another schematic diagram of a portable therapeutic cooling
system according to one embodiment of the present invention.
[0017] FIGURE 7 is another schematic diagram of a portable therapeutic cooling
system according to one embodiment of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0018] The present invention overcomes the deficiencies of the prior art
through the
development of a portable therapeutic cooling system adapted to be applied as
soon as
possible to the patient after the health event, that is adapted to be used in
transitory settings,
such as in an ambulance, or in a patient's immediate area, such as the
patient's home, that is
adapted to be operated by a bystander, paramedic, or other nearby personnel
and can be used
effectively on clothed patients.
[0019] Referring first to FIGURE 1, a top partial cutaway view of a
therapeutic
cooling system is shown according to one embodiment of the present invention.
The cooling
system 100 includes an inflatable unitary head and body suit 102 coupled to a
cooling unit
104. The inflatable suit 102 is preferably composed of disposable material
capable of
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allowing air to circulate through the inflatable suit 102, but non-disposable
embodiments are
contemplated to be within the scope of this invention. The inflatable suit 102
is adapted to be
sealed about the patient along a seam 106, such as by a zipper, buttons or
other equivalent
fastening means, although the convective nature of the heat transfer from the
inflatable suit
102 to the patient does not require the inflatable suit 102 to be sealed about
the patient in
order for the patient to be cooled.
[0020] The suit 102 may be designed in small, medium, large and extra-large
configurations or otherwise sized to shape pediatric patients, depending on
the requirements
of the user. The suit 102 is suitably adapted to circulate air throughout the
suit 102 while
preventing the air from escaping to the environment, and has an air inlet port
108 and an air
outlet port 110. The air inlet port 108 is preferably connected to the cooling
unit 104 via
hoses or the like, which delivers cooled air from a source to the suit 102.
The air outlet port
110 is adapted to deliver air circulated through the suit 102 to the cooling
unit 104 via hoses
or the like for re-circulation into the suit 102 via the air inlet port 108.
[0021] The suit 102 is adapted to deliver cooling to the patient via
convective heat
transfer. The suit 102 is further adapted to provide cooling to critical areas
such as the neck,
scalp, and groin.
[0022] When a person undergoes a traumatic health event, the bystander,
paramedic
or other nearby person may easily slide the clothed person into the suit 102
and close the suit
102 via the seam 106. Upon sealing, the cooling unit 104 is either activated,
if already
connected to the suit, or connected to the air inlet port 108 and air outlet
port 110 and then
activated. Cool air is then directed to flow throughout the suit and
convectively cool the
patient's body by encompassing a significant percentage of the patient's
entire body. The re-
circulation feature of the suit 102 allows the system to operate efficiently
and maintain the air
at a predetermined cooling temperature.
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[0023] Although not specifically shown in this FIGURE .1, a power source, such
as a
12 V. D.C. device¨such as those available in ambulances¨or other power sources
including
A.C. current-delivering devices may be suitably used to power the cooling unit
104.
Alternatively, a battery may be included in the cooling unit 104. =
[0024] Referring now to FIGURE 2, a top-plan view of a portable therapeutic
cooling
system 200 in accordance with another embodiment of the present invention is
shown. The
portable therapeutic cooling system 200 is adapted to be placed about a
patient's head and
neck only, and cool the head and neck, including the carotid artery. One of
skill in the art
will appreciate that the placement of the portable therapeutic cooling system
200 will allow
other parts of the body to be cooled as well via normal blood circulation in a
patient's body.
As such, a hood 202 is provided connected to a cooling unit 204. The hood 202
provides
convective airflow through the hood .202 around the scalp of a patient in a
closed loop, and
further includes means to provide a transmission path for the air in an effort
to cool the
patient's brain, such as emissary veins in an open loop. The hood 202 further
includes
stretchers 206 in the fabric structure thereof to provide space for allowing
circulation of air
around the scalp.
[0025] An air inlet port 208 is provided on the hood 202 for connecting a
delivery
tube 210 to the cooling unit 204. When the cooling unit 204 is activated, cold
air is delivered
through the delivery tube 210 and into the hood 204, where it circulates
around the head and
neck area of the patient and provides convective cooling.
[0026] Referring now to FIGURE 3, a schematic diagram of a portable
therapeutic
cooling system 300 is shown according to one embodiment of the present
invention. A
control unit 302 is provided, which receives temperature input from a
temperature sensor 303
between a heat exchanger 304 and the output devices, such as the hood 306 and
suit 308. The
control unit 302 provides a speed control signal to an air blower 310, which,
in turn, blows air
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over the heat exchanger 304 in communication with a cooling source 314. A
pressure sensor
316 may be provided between the air blower 310 and heat exchanger 304 and
connected to
the control unit 302 to assist the control unit 302 in determining the
appropriate speed of the
air blower 310.
[0027] Accordingly, when the control unit 302 is activated, it first
determines the
temperature from the temperature sensor 303 and the pressure from the pressure
sensor 316.
The control unit 302 then provides a signal to the air blower 310, which
activates and blows
air over the heat exchanger 304. The resulting air is then transmitted to
either the hood 306
or the suit 308, depending on which device is connected to the system 300.
[0028] Referring now to FIGURE 4, another schematic diagram of a portable
therapeutic cooling system 400 according to one embodiment of the present
invention is
shown. The cooling system 400 is provided with a pettier element 402 in
combination with a
heat exchanger for controlling the temperature of air passing therethrough. A
control unit
404 is connected to an air blower 406, a diverter valve 408 and a temperature
sensor 410.
The diverter valve 408 is prepositioned between the air blower 406 and the
pettier element
402 and directs airflow accordingly over the hot side or cold side of the
pettier element 402
based on the control unit 404 and the requirement to warm or cool. The
temperature sensor
410 is placed downstream from the pettier element 402 and upstream of either
the hood 412
or suit 414, depending on the configuration of the system 400. ,As such, the
cooling system
400 provides sufficient thermal control to the patient when using the hood 412
or suit 414. It
is to be appreciated that the hood 412 or suit 414 may be inflatable, and that
the hood 412 or
suit 414 may be unitary.
[0029] Referring now to FIGURE 5, another schematic diagram of an alternate
cooling supply 500 used with the portable therapeutic system of FIGURE 6 is
shown. The
alternate cooling supply 500 is compressed gas, which is often stored in
containers such as
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container 502. The container 502 is connected to a proportional valve 504,
which in turn is
connected to a control unit (not shown), and may be connected to a heat
exchanger (not
shown). Alternatively, instead of connecting to a heat exchanger, the valve
504 may be
connected to a dilution device (not shown) to dilute the compressed gas with
air. Liquid air
may be used as the compressed gas.
[0030] FIGURE 6 is another schematic diagram of a portable therapeutic cooling
system 600 according to one embodiment of the present invention. The system
600 includes
a control unit 602, an air mover 604 connected to the control unit 602 and to
either a hood
606 or suit 608 as desired. A compressed gas container 610 is further provided
connected to
a valve 612. The valve 612 is connected to the control unit 602, and to an
area upstream of
the air mover 604 before the hood 606 or suit 608. A temperature sensor 614 is
provided in
the same area and connected to the control unit 602 for providing temperature
data to the
control unit 602 during operation.
[0031] When the suit 608 is used, air is re-circulated from the suit 608 to
the air
mover 604 to increase the efficiency of the system. The compressed gas, such
as liquid air,
provides a cool stream of air to the hood 606 or suit 612, and thereby
eliminates the need for
a heat exchanger. Flow from the container 610 is controlled by the valve 612,
which in turn
is directed to increase or decrease the airflow therethrough by the control
unit 602. Although
air is used in terminology, it is to be understood that air may comprise any
gas, including
fluid, capable of providing cooling to the output device. It is to be further
understood that the
hood 606 or suit 608 may be inflatable, and that the hood 606 or suit 612 may
be unitary.
[0032] Referring now to FIGURE 7, another schematic diagram of an alternate
portable therapeutic cooling system 700 is shown. A control unit 702 is
provided, which
receives temperature input from a temperature sensor 703 between a heat
exchanger 704 and
the output devices, such as the hood 706 and suit 708. The control unit 702
provides a speed
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control signal to an air blower 710, which, in turn, blows air over a heat
exchanger 704 in
communication with ice 712. A re-circulation line may be provided between the
suit 708 and
the air blower 710, which may be a pump or the like, to increase the cooling
efficiency of the
system 700. The ice 712 provides a generally readily available cooling source
for users of
the system 700 in the event of emergency.
[0033] It is to be appreciated that each of the embodiments shown in the
FIGURES
are portable, and adapted to be disposable, though not limited to this
feature. As such, the
embodiments shown herein provide an efficient, portable therapeutic cooling
system that may
be conveniently used by bystanders, paramedics, or anyone who is available to
assist after a
patient undergoes a significant or life threatening health event, with little
instruction required.
It is further to be appreciated that the cooling disclosed herein is typical
of that of a
convective cooling system, though conductive, radiation or alternate heat-
transfer
mechanisms adapted to be portable are contemplated to be within the scope of
this invention.
Both the hood and suit in the embodiments shown is adapted to be disposable to
avoid the
necessary decontamination procedures that would normally accommodate re-use of
these
devices. It is to be further appreciated that when the term air is used, it
encompasses any gas,
including a liquid, capable of provided cooling to the respective output
device (e.g. the hood,
suit, and unitary head and body suit).
[0034] The previous description is of preferred embodiments for implementing
the
invention, and the scope of the invention should not necessarily be limited by
this description.
The scope of the present invention is instead defined by the following claims.
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