U.S. patent application number 10/126251 was filed with the patent office on 2003-02-06 for heat-exchange device with improved seal.
Invention is credited to Grahn, Dennis A., Inouye, Matthew D., Licata, David William, Lyons, David Frederick, Macgregor, Bruce G., Pelman, Todd Allen, Samuels, Rudy Lucas, Zeh, Mark A..
Application Number | 20030024684 10/126251 |
Document ID | / |
Family ID | 23092573 |
Filed Date | 2003-02-06 |
United States Patent
Application |
20030024684 |
Kind Code |
A1 |
Lyons, David Frederick ; et
al. |
February 6, 2003 |
Heat-exchange device with improved seal
Abstract
A module for thermal exchange with a portion of a mammal is
provided. The module is used with advanced methods related to body
temperature control and management. A portion of a mammal is placed
in a sealed enclosure that is in thermal communication with a heat
exchange fluid. The enclosure is also adapted to provide a negative
pressure environment and includes an improved interface with the
external environment.
Inventors: |
Lyons, David Frederick;
(Palo Alto, CA) ; Grahn, Dennis A.; (Palo Alto,
CA) ; Macgregor, Bruce G.; (Palo Alto, CA) ;
Pelman, Todd Allen; (San Francisco, CA) ; Zeh, Mark
A.; (Mountain View, CA) ; Samuels, Rudy Lucas;
(Bolinas, CA) ; Licata, David William; (Menlo
Park, CA) ; Inouye, Matthew D.; (Foster City,
CA) |
Correspondence
Address: |
Rimas T. Lukas
Morrison & Foerster LLP
755 Page Mill Road
Palo Alto
CA
94304-1018
US
|
Family ID: |
23092573 |
Appl. No.: |
10/126251 |
Filed: |
April 19, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60285060 |
Apr 19, 2001 |
|
|
|
Current U.S.
Class: |
165/45 |
Current CPC
Class: |
A61F 7/03 20130101; A61F
2007/0045 20130101; A61F 7/02 20130101; A61F 2007/0239 20130101;
A61F 2007/0029 20130101; A61F 2007/0054 20130101 |
Class at
Publication: |
165/45 |
International
Class: |
F28D 001/00 |
Claims
1. A module for thermal exchange with a portion of a mammal;
comprising: a first chamber defining a chamber opening and adapted
to receive a portion of the mammal; an exchange surface in thermal
communication with the first chamber; and a seal connected to the
first chamber at the chamber opening; the seal including a seal
opening and a waist opening; the chamber opening and the seal
opening being greater than the waist opening such that a ramped
entry and exit is provided for the portion of the mammal.
2. The module of claim 1 wherein the seal is substantially
hourglass shaped.
3. The module of claim 1 wherein the seal is made from an elastic
material such that the waist opening varies with the insertion of
the portion of the mammal and substantially conforms to seal
against the portion of mammal.
4. The module of claim 1 wherein the waist opening is regulated by
an inflatable bladder, expansion means, belt, cinch, or strap.
5. The module of claim 1 wherein the waist opening is substantially
elliptical in shape.
6. The module of claim 1 wherein the seal is made from an elastic
material such that the seal opening varies with the insertion of
the portion of the mammal and substantially conforms to seal
against the portion of mammal.
7. The module of claim 1 further including a second chamber adapted
to receive a thermal exchange medium; the second chamber being in
thermal communication with the exchange surface.
8. The module of claim 1 wherein the seal is part of a seal
cartridge that is removably coupled to the first chamber.
9. A module for thermal exchange with a portion of a mammal,
comprising: a housing including: a first chamber including a
chamber opening and adapted to receive a portion of a mammal; and
an exchange surface in thermal communication with the first
chamber; and a seal connected to the first chamber at the chamber
opening; the seal forming a variable opening adapted to
substantially conform against the mammal to contact the portion of
the mammal inside the first chamber.
10. The module of claim 9 further including a vacuum source coupled
to the first chamber such that the vacuum source is capable of
drawing a negative pressure in the first chamber.
11. The module of claim 9 wherein the seal includes two pieces.
12. The module of claim 9 further including a second chamber
adapted to receive a thermal exchange medium; the second chamber
being in thermal communication with the exchange surface.
13. A module for thermal exchange with a portion of a mammal,
comprising: a housing including: a first chamber adapted to receive
a portion of a mammal and adapted to provide a negative pressure
environment, the first chamber including a chamber opening; and an
exchange surface in thermal communication with the first chamber;
and a seal connected to the first chamber at the chamber opening
and having a longitudinal axis; the seal comprising a flexible wall
member that provides substantial contact sealing against at least a
portion of the external surface of the mammal while accommodating
motion of the portion of the mammal that is lateral to the
longitudinal axis.
14. The module of claim 13 further including a second chamber
adapted to receive a thermal exchange medium; the second chamber
being in thermal communication with the first chamber.
15. The module of claim 13 wherein the seal leaks air with motion
of the portion of the mammal that is substantially lateral to the
longitudinal axis.
16. A module for thermal exchange with a portion of a mammal,
comprising: a housing including: a first chamber including a
chamber opening; the first chamber being adapted to receive a
portion of a mammal and being adapted to provide a negative
pressure environment; and an exchange surface in thermal
communication with the first chamber; and a seal connected to the
first chamber at the chamber opening; the seal comprising a
flexible sleeve including a waist portion; at least the waist
portion being adapted to engage at least a portion of the external
surface of a portion of the mammal; the sleeve being deflectable
with movement of the portion of the mammal.
17. The module of claim 16 wherein the waist portion defines a
waist opening; the waist opening including a relaxed position; the
waist opening being expandable relative to the relaxed position
with insertion of the portion of the mammal.
18. The module of claim 17 wherein the waist opening substantially
conforms to circumferentially contact the portion of the
mammal.
19. The module of claim 16 further including a second chamber
adapted to receive a thermal exchange medium; the second chamber
being in thermal communication with the first chamber.
20. The module of claim 16 wherein the waist portion defines a
waist opening; the waist opening including a relaxed position; the
waist opening being expandable relative to the relaxed position via
expansion means.
21. The module of claim 16 further including stop means for
maintaining the seal in a non-relaxed expanded position.
22. The module of claim 20 wherein the expansion means is selected
from the group consisting of cordage, mechanical linkage and other
expansion means known to one skilled in the art.
23. A module for thermal exchange with a portion of a mammal,
comprising: a housing including: a first chamber being adapted to
receive a portion of a mammal and adapted to provide a negative
pressure environment; the first chamber including a chamber
opening; and an exchange surface in thermal communication with the
first chamber; and a seal connected to the first chamber at the
chamber opening; the seal including an elastic element to bias the
seal against the portion of the mammal.
24. The module of claim 23 wherein the seal includes a longitudinal
axis, the seal being laterally deflectable relative to the
longitudinal axis with motion of the portion of the mammal.
25. The module of claim 23 wherein the seal defines a waist portion
having a variable waist opening, the waist portion having at least
a relaxed position and an engaged position; the waist opening being
smaller when in a relaxed position relative to the portion of the
mammal against which the seal engages.
26. The module of claim 23 wherein the seal includes a longitudinal
axis, and wherein the seal is adapted to leak air from the first
chamber with substantial lateral displacement of the portion of the
mammal relative to the longitudinal axis.
27. The module of claim 23 further including a second chamber
adapted to receive a thermal exchange medium; the second chamber
being in thermal communication with the exchange surface.
28. The module of claim 23 wherein the seal includes an elastic
element such that when the negative pressure environment is
established in the first chamber, the seal will bow inwardly to
bias the seal against the portion of the mammal.
29. A module for thermal exchange with a portion of a mammal,
comprising: a first chamber defining a chamber opening and a port;
the first chamber being adapted to receive a portion of a mammal
via the chamber opening; the first chamber being adapted to receive
a negative pressure via the port; an exchange surface in thermal
communication with the first chamber; and a seal connected to the
first chamber at the chamber opening to seal the portion of the
mammal inside the first chamber.
30. The module of claim 29 wherein the seal substantially
corresponds to the shape of the portion of the mammal.
31. The module of claim 29 wherein the seal includes a seal opening
and a waist opening; the seal opening being larger than the waist
opening to provide ramped entry and exit for the portion of the
mammal.
32. The module of claim 29 and 31 wherein the seal includes a
chamber opening and a waist opening; the chamber opening being
larger than the waist opening to provide a ramped entry and exit
for the portion of the mammal.
33. The module of claim 29 wherein the seal includes a waist
opening that is smaller than the chamber opening of the first
chamber; the waist opening being variable.
34. The module of claim 29 wherein the seal includes a variable
seal opening.
35. The module of claim 34 wherein the seal includes a waist
opening; the seal opening being larger than the waist opening; the
waist opening being variable.
36. The module of claim 29 wherein the seal includes a chamber
opening and a waist opening; the chamber opening of the seal is
larger than the waist opening; the chamber opening and the waist
opening being variable.
37. The module of claim 29 wherein the seal is made of a material
that is capable of stretching isotropically.
38. The module of claim 29 wherein the seal is made of a material
that is capable of stretching anisotropically such that the seal
stretches in a direction lateral to a longitudinal axis of the
seal.
39. The module of claim 29 wherein the seal includes reinforcement
members.
40. The module of claim 29 wherein the first chamber substantially
corresponds to the shape of the portion of the mammal.
41. The module of claim 29 wherein the seal includes a longitudinal
axis and is flexible such that lateral movement relative to the
longitudinal axis of the portion of the mammal is substantially
afforded while maintaining a contact seal against the portion of
the mammal.
42. The module of claim 29 and 41 wherein the seal includes a
longitudinal axis and is flexible such that lateral movement
relative to the longitudinal axis of the portion of the mammal is
substantially afforded while allowing air to leak across the
seal.
43. The module of claim 29 further including: a vacuum pump coupled
to the first chamber to draw air from the first chamber; a control
system coupled to the vacuum pump; the control system being adapted
to maintain the pressure of the first chamber at a set-point.
44. The module of claim 43 wherein the control system is adapted to
extract air from the first chamber at a vacuum flow rate that is
substantially equal to the air leak rate into the first
chamber.
45. The module of claim 29 further including a second chamber
adapted to receive a thermal exchange medium; the second chamber
being in thermal communication with the first chamber.
46. A module for thermal exchange with a portion of a mammal,
comprising: a housing having a first end and a second end
comprising: a chamber adapted to receive a portion of the mammal; a
heat exchange cavity in thermal communication with the chamber; a
seal connected to the housing at the second end; the seal defining
a chamber opening, a waist opening, and a seal opening; the waist
opening being located between the chamber opening and the seal
opening; the chamber opening being located proximate to the plate
relative to the seal opening; and a seal frame connected to the
housing at the second end and supporting the seal.
47. The module of claim 46 wherein the housing includes: a heat
exchange element located between the chamber and the heat exchange
cavity.
48. The module of claim 47 wherein the housing includes: a cover;
and a base connected to the cover.
49. The module of claim 48 wherein the heat exchange element is
located between the cover and the base.
50. The module of claim 49 wherein the heat exchange cavity is
defined between the heat exchange element and the base.
51. The module of claim 46 wherein the housing further includes an
end cap connected to the first end.
52. The module of claim 51 wherein the end cap includes at least
one port in fluid communication with the chamber.
53. The module of claim 46 wherein the housing further includes a
plate connected to the second end; the plate including an opening
to the chamber.
54. The module of claim 53 wherein the plate includes an inlet port
and an outlet port in fluid communication with the heat exchange
cavity.
55. The module of claim 46 wherein the chamber opening and the seal
opening are greater than the waist opening providing a ramped
entry.
56. The module of claim 46 wherein the seal frame includes: a first
ring connected to the seal at the chamber opening; the first ring
being connected to the plate; a retainer member; a second ring; the
seal being captured between the retainer member and the second
ring; and at least one standoff interconnecting the retainer member
and the plate.
57. The module of claim 46 wherein the seal frame includes: a first
frame element supporting a first end of the seal; and a second
frame element supporting a second end of the seal.
58. The module of claim 57 wherein the seal frame forms a seal
cartridge that is removably attached to the housing.
59. The module of claim 57 wherein the first frame element includes
a ring and a first and second retaining member; the first end of
the seal being coupled to the ring and captured between the first
and second retaining members.
60. The module of claim 57 or 59 wherein the second frame element
includes a ring and a first and second retaining member; the second
end of the seal being coupled to the ring and captured between the
first and second retaining members.
61. The module of claim 46 wherein the seal includes a first end
and a second; the first end of the seal being rotatable relative to
the second end of the seal to reduce at least the waist
opening.
62. The module of claim 46 further including a sheath that
encompases the seal such that the sheath is substantially coaxial
with respect to the seal; the sheath having a first end and a
second end and a sheath opening; the first end of the sheath being
rotatable relative to the second end of the sheath to reduce the
sheath opening and at least the waist opening of the seal.
63. The module of claim 62 further including a sheath frame
connected to the housing and supporting the sheath.
64. A module for thermal exchange with a portion of a mammal,
comprising: a base having an exchange surface and a base perimeter;
a cover connected to the base to form a chamber for receiving the
portion of a mammal such that the portion of the mammal is in
thermal communication with the exchange surface; the chamber being
adapted to receive a negative pressure environment relative to
atmospheric pressure; the cover having a cover perimeter and a seal
for contacting the portion of the mammal to substantially prevent
leakage of air across the seal.
65. The module of claim 64 wherein the exchange surface has an
outer surface adapted to receive a heat exchange element.
66. The module of claim 64 wherein the exchange surface is made
from thermally conductive material.
67. The module of claim 66 wherein the exchange surface is made of
flexible material.
68. The module of claim 67 wherein the exchange surface bows
inwardly into the chamber upon the application of a negative
pressure to contact the portion of the mammal.
69. The module of claim 64 wherein the cover is rotatably coupled
to the base such that the module includes at least an open position
and at least a closed position such that when in the closed
position at least a portion of the base perimeter is aligned with
at least a portion of the cover perimeter.
70. The module of claim 69 wherein at least one of the base
perimeter or cover perimeter includes an adhesive.
71. The module of claim 64 wherein a portion of the base perimeter
includes an base opening portion.
72. The module of claim 71 wherein the seal is located in the base
opening portion.
73. The module of claim 64 wherein a portion of the cover perimeter
includes a cover opening portion.
74. The module of claim 73 wherein the seal is located in the cover
opening portion.
75. The module of claim 64 wherein a portion of the cover perimeter
includes a cover opening portion; a portion of the base perimeter
includes a base opening portion; the module having at least an open
position and at least a closed position such that when in the
closed position the cover opening are aligned to form an
opening.
76. The module of claim 75 wherein the seal is a split seal such
that a portion of the seal is disposed in the cover opening portion
and a portion of the seal is disposed within the base opening
portion.
77. A method for thermal exchange with a portion a mammal
comprising the steps of: providing a module having a chamber for
receiving a portion of the mammal; the module including a seal that
allows a variable leakage of air across the seal; providing a
vacuum pump coupled to the chamber to draw air from the chamber;
providing a control system coupled to the vacuum pump for
regulating the air pressure within the chamber; selecting a
pressure set-point; establishing an air pressure inside the chamber
that is substantially equal to the pressure set-point; maintaining
the pressure set-point within the chamber.
78. The method of claim 77 wherein the step of maintaining the
pressure set-point includes extracting air from the chamber at a
vacuum flow rate that is substantially equal to the air leak rate
into the first chamber.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] The present application is related to and claims priority
from the U.S. Provisional Patent Application Serial No. 60/285,060
filed on Apr. 19, 2001 entitled "Negative pressure heat-exchange
device with improved seal", the disclosure of which is herein
incorporated by reference in its entirety.
FIELD OF INVENTION
[0002] This application relates to body temperature control and
management, and more particularly to, a system for applying or
removing thermal energy to or from a mammalian body, the system
having an improved interface with the external environment.
BACKGROUND
[0003] Regulating human or mammalian body temperature is desirable
in many instances. For example, it may be desirable to raise the
core body temperature to treat hypothermia arising, for example,
from prolonged exposure to cold environments, trauma or
post-operative conditions. Raising body temperature to induce
hyperthermia is desirable as well. For example, various treatments
for viral diseases and cancers call for elevated body temperatures.
Another avenue for body temperature regulation is the lowering of
body temperature to treat hyperthermia that may arise, for example,
from fever, heat stroke, extreme environments, multiple sclerosis,
exercise or exertion induced conditions. Lowering body temperature
to induce hypothermia is also desirable to minimize damage to the
brain when a patient has suffered a stroke, for example, or to
minimize damage to heart or brain tissue when a patient has
undergone cardiac arrest. It may sometimes also be desirable to
induce hypothermia during surgery to minimize tissue damage.
Generally, there are numerous therapeutic reasons for thermal
regulation that is aimed at raising, maintaining or lowering body
temperature. Whether to induce certain therapies or to normalize
body temperature, core body temperature control and management is
valuable and potentially life-saving.
[0004] Advanced temperature control and management involves not
only adding or removing heat, but also, includes an understanding
of the complex autonomic thermoregulatory system within the body.
Examples of thermoregulatory responses that maintain the body at a
near constant normothermic temperature include sweating and
vasodilation to enhance heat loss, arterio venous shunting and
vasoconstriction to enhance heat retention, and shivering to
enhance increased production of body heat. One important effector
of the regulatory system is blood flow to specialized skin areas
where heat from the deep body core can be dissipated to the
environment. Normally, when body and/or environmental temperatures
are high, the dilation of certain blood vessels favors high blood
flow to these surfaces, and as environmental and/or body
temperatures fall, vasoconstriction reduces blood flow to these
surfaces and minimizes heat loss to the environment. Generally,
thermoregulatory mechanisms provide a formidable defense when
attempts are made to change the body temperature and there is a
great interest in the development of methods in which the
thermoregulatory system is manipulated so that energy can be
transferred into or out of the core body without triggering an
opposing thermoregulatory response.
[0005] Core body temperature control and management methods may
involve various drugs and methods that are employed to control the
thermoregulatory response so that energy may be added or removed as
efficiently and safely as possible. One temperature control and
management method involves the application of a negative pressure
to a portion of the body in order to induce vasodilatation for
regulated heat transfer. Devices for practicing temperature control
and management methods that involve the application of a negative
pressure include means for providing the negative pressure
environment for a portion of the body as well as a heat exchange
medium. In many embodiments, this means for providing a negative
pressure environment includes a means for sealing a portion of the
mammal's body in an enclosed environment in which negative pressure
conditions can be produced. Representative enclosing means include
sleeves, boots/shoes, gloves, etc. which are in operational
relationship with a negative pressure inducing means, e.g., a
vacuum, that is capable of producing a negative pressure
environment in a sealed enclosure. The devices also include a means
for thermal communication with a heat exchange medium. The
interface of the negative pressure environment with the environment
outside of the sealed enclosure must permit a portion of the mammal
to be received and be substantially sealed within the enclosure
while maintaining an adequate negative pressure within the
environment.
[0006] Aquarius, Inc. (Scottsdale, Ariz.) produces a system that
utilizes a "hard" seal interface with a user. A "hard" seal is
characterized as one designed to altogether avoid air leakage past
the boundary it provides. In theory, a "hard" seal will allow a
single evacuation of the negative pressure chamber for use in the
methods. In practice, however, a "hard" seal can produce a
tourniquet effect. Hence, it is desirable that the chamber
interface substantially prevents escape of vacuum air without
unduly constricting the portion of the body that is sealed within
the negative pressure environment. The "soft" seal as described in
the present invention provides a unique solution to this problem
while accommodating movement of the portion of the normal. However,
the "soft" seal of the present invention that accommodates movement
is susceptible to leaks across the seal. These leaks are variable
in terms of degree of leak flow rate and, hence, a unique vacuum
regulation control method is additionally set forth in this
invention.
[0007] Another challenge is providing a seal configuration that
permits ease of entry and exit from the device. Entry and exit from
the Aquarius seal is difficult. Whether "hard" or "soft" in
function, the system of this invention provides an advantageous
solution.
SUMMARY OF INVENTION
[0008] In accordance with one aspect of the invention, there is
provided a module for thermal exchange with a portion of a mammal.
The module includes a first chamber that defines a chamber opening
and is adapted to receive the portion of the mammal. The module
includes an exchange surface in thermal communication with the
first chamber. A seal is connected to the first chamber at the
chamber opening. The seal includes a seal opening and a waist
opening. The chamber opening and the seal opening are greater than
the waist opening such that a ramped entry and exit is provided for
the portion of the mammal.
[0009] In accordance with another aspect of the invention, there is
provided a module for thermal exchange with a portion of a mammal.
The module includes a housing including a first chamber and an
exchange surface. The first chamber includes a chamber opening and
is adapted to receive a portion of a mammal. The exchange surface
is in thermal communication with the first chamber. A seal is
connected to the first chamber at the chamber opening. The seal
forms a variable opening adapted to substantially conform against
the mammal to seal the portion of the mammal inside the first
chamber.
[0010] In accordance with yet another aspect of the invention,
there is provided a module for thermal exchange with a portion of a
mammal. The module includes a housing including a first chamber and
an exchange surface. The first chamber is adapted to receive a
portion of a mammal and is adapted to provide a negative pressure
environment. The first chamber includes a chamber opening. The
exchange surface is in thermal communication with the first
chamber. A seal is connected to the first chamber at the chamber
opening. The seal has a longitudinal axis and comprises a flexible
wall member that provides substantial contact sealing against at
least a portion of the external surface of the mammal while
accommodating motion of the portion of the mammal that is lateral
to the longitudinal axis.
[0011] In accordance with another aspect of the invention, there is
provided a module for thermal exchange with a portion of a mammal.
The module includes a housing including a first chamber and an
exchange surface. The first chamber includes a chamber opening. The
first chamber is adapted to receive a portion of a mammal and is
adapted to provide a negative pressure environment. The exchange
surface is in thermal communication with the first chamber. A seal
is connected to the first chamber at the chamber opening. The seal
comprises a flexible sleeve including a waist portion. The waist
portion is adapted to engage at least a portion of the external
surface of a portion of the mammal. The sleeve is deflectable with
movement of the portion of the mammal.
[0012] In accordance with another aspect of the invention, there is
provided a module for thermal exchange with a portion of a mammal.
The module includes a housing including a first chamber and an
exchange surface. The first chamber is adapted to receive a portion
of a mammal and is adapted to provide a negative pressure
environment. The first chamber includes a chamber opening. The
exchange surface is in thermal communication with the first
chamber. A seal is connected to the first chamber at the chamber
opening. The seal includes an elastic element to bias the seal
against the portion of the mammal.
[0013] In accordance with yet another aspect of the invention,
there is provided a module for thermal exchange with a portion of a
mammal. The module includes a first chamber and an exchange
surface. The first chamber defines a chamber opening and a port.
The first chamber is adapted to receive a portion of a mammal via
the chamber opening. The first chamber being adapted to receive a
negative pressure via the port. The exchange surface is in thermal
communication with the first chamber. A seal is connected to the
first chamber at the chamber opening to seal the portion of the
mammal inside the first chamber.
[0014] In accordance with another aspect of the invention, there is
provided a module for thermal exchange with a portion of a mammal.
The module includes a housing having a first end and a second end.
The housing includes a chamber that is adapted to receive a portion
of the mammal and a heat exchange cavity in thermal communication
with the chamber. A seal is connected to the housing at the second
end. The seal defines a chamber opening, a waist opening, and a
seal opening. The waist opening is located between the chamber
opening and the seal opening. The chamber opening is located
proximate to the plate relative to the seal opening. A seal frame
is connected to the housing at the second end and supports the
seal.
[0015] In accordance with another aspect of the invention, there is
provided a module for thermal exchange with a portion of a mammal
that includes a base having an exchange surface and a base
perimeter. The module further includes a cover connected to the
base to form a chamber for receiving the portion of a mammal such
that the portion of the mammal is in thermal communication with the
exchange surface. The chamber is adapted to receive a negative
pressure environment relative to atmospheric pressure. The cover
has a cover perimeter. The module includes a seal for contacting
the portion of the mammal to substantially prevent leakage of air
across the seal.
[0016] In accordance with another aspect of the invention, there is
provided a method for thermal exchange with a portion a mammal. The
method comprises the steps of providing a module having a chamber
for receiving a portion of the mammal. The module includes a seal
that allows a variable leakage of air across the seal. A vacuum
pump that is coupled to the chamber to draw air from the chamber is
also provided. A control system that is coupled to the vacuum pump
for regulating the air pressure within the chamber is also
provided. The method further includes the steps of selecting a
pressure set-point and establishing an air pressure inside the
chamber that is substantially equal to the pressure set-point.
Furthermore, the method includes the step of maintaining the
pressure set-point within the chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The foregoing and other advantages of the invention will
become apparent upon reading the following detailed description and
upon reference to the drawings in which:
[0018] FIG. 1 is a fore perspective view of the thermal exchange
module of the present invention;
[0019] FIG. 2 is an aft perspective view of the thermal exchange
module of the present invention;
[0020] FIG. 3 is an exploded view of the thermal exchange module of
the present invention;
[0021] FIG. 4 is a rear elevational view of the thermal exchange
module of the present invention;
[0022] FIG. 5 is a cross-sectional view along line A-A of FIG. 4 of
the thermal exchange module of the present invention;
[0023] FIG. 6 is a cross-sectional view along line B-B of FIG. 4 of
the thermal exchange module of the present invention;
[0024] FIG. 7 is a perspective view of the thermal exchange module
of the present invention;
[0025] FIG. 8 is a perspective view of the thermal exchange module
with a detached seal cartridge of the present invention;
[0026] FIG. 9 is an exploded view of the thermal exchange module of
the present invention;
[0027] FIG. 10 is a perspective view of the thermal exchange module
of the present invention;
[0028] FIG. 11 is a perspective view of the thermal exchange module
of the present invention;
[0029] FIG. 12 is a perspective view of the thermal exchange module
and heat exchange element of the present invention; and
[0030] FIG. 13 is a perspective view of the thermal exchange module
of the present invention with a human hand inserted therein.
[0031] While the invention is susceptible to various modifications
and alternative forms, specific variations have been shown by way
of example in the drawings and will be described herein. However,
it should be understood that the invention is not limited to the
particular forms disclosed. Rather, the invention is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the invention as defined by the appended
claims.
DETAILED DESCRIPTION
[0032] This invention relates generally to hardware configured for
carrying out the methodologies in particular, those described in
Provisional Patent Application entitled METHODS AND DEVICES FOR
EXTRACTING THERMAL ENERGY FROM THE BODY CORE OF A MAMMAL filed on
Apr. 20,2000, Provisional Patent Application entitled METHODS AND
DEVICES FOR ENHANCING THE PHYSICAL ABILITY OF A MAMMAL filed on
Apr. 20,2000, Provisional Patent Application entitled METHODS AND
DEVICES FOR MANIPULATING THE THERMOREGULATORY STATUS OF A MAMMAL
filed on Jun. 9,2000 and Provisional Patent Application entitled
METHODS AND DEVICES FOR PREVENTION OF HYPOTHERMIA IN A MAMMAL
DURING PROLONGED EXPOSURE TO EXTREME COLD, each to Dr. H. Craig
Heller and Dr. Dennis Grahn, and each incorporated by reference
herein in its entirety.
[0033] FIGS. 1 and 2 provide fore and aft perspective views of a
negative pressure thermal exchange module (100). FIG. 3 provides an
exploded view of the same. The system components not shown in the
figures include a thermal control or perfusion unit. Such a unit
may be adapted to provide a stream of heat exchange media such as
fluid at elevated temperatures, lowered temperatures or both.
Various methods of thermal exchange known to those skilled in the
art fall within the scope of this invention. Examples of thermal
exchange methods include employing a temperature-controlled fluid,
thermoelectric elements, desiccants, micro-refrigeration, and
chemical reactions. Examples of temperature-controlled fluids
include water, alcohol, and chlorofluorocarbons (CFCs). Further, a
vacuum source and regulator optionally used with module (100) are
not shown. Any sort of vacuum source or regulator/control mechanism
may be used with module (100) as would be apparent to one with
skill in the art. At least one unique vacuum control mechanism is
described below. Together, these components work to maintain a
desired pressure and temperature within module (100) during
use.
[0034] As shown, module (100) includes a housing (102) defining a
negative pressure chamber (104), a heat-exchange element (106) and
a soft, two-sided seal (108) supported by seal frame elements
(110).
[0035] Housing (102) may be made from a cover (112) and a base
(114). Negative pressure chamber (104) is preferably provided
between heat exchange element (106) and cover (112). Chamber (104)
is adapted to receive a portion of a mammal and to provide a
negative pressure environment. The chamber (104) is in thermal
communication with the heat exchange element (106) that is in
thermal communication with a working medium located in a heat
exchange cavity (126). In one embodiment, the heat exchange cavity
(126) is external to the module (100). The embodiment shown is
adapted to fit the hand of a human user. Chamber (104) is
preferably configured to fit a human hand of any size, however the
invention is not so limited and any functional portion of a mammal
may be employed. In order to provide a more space-efficient
package, however, it may be more preferably sized to fit 95% of
human hand sizes. Alternately, it may be sized for more
particularized groups, such as children. It is also contemplated
that the housing (102) may be configured to fit a human foot since
the under surface of a foot may also be used effectively as a heat
exchange surface.
[0036] Housing (102) may be constructed from multiple pieces,
including an end cap (116) as shown, or it may be provided as a
unitary structure. Cap (116) is shown including a ports (118). A
first port may be utilized for connection to a vacuum source, while
the second may be utilized for a vacuum gauge. Of course, alternate
port placement is also possible.
[0037] Preferably, housing (102) is made of plastic. Most
preferably, the material and design of at least a portion of module
(100) are such that housing (102) may be produced by vacuum forming
or molding techniques.
[0038] Where discrete cover (112) and base (114) portions are used,
they may be mechanically secured to one another via fastening means
such as through bolt holes (120), adhesive, or retention bands that
help form a substantially airtight seal. In such an instance, a
gasket or caulking may be employed to seal the periphery of housing
(102).
[0039] Providing a separable cover (112) and base (114) or heat
exchange element (106) provide advantageous access to clean module
(100) after use. However, it is contemplated that the top and
bottom portions of the module may be fused together, for instance,
by ultrasonic welding, chemical bonding or otherwise. Also, as
noted above, it is contemplated that housing (102) may be provided
in a single piece.
[0040] Regardless of the construction, sizing or overall appearance
of housing (102), it defines a portion of chamber (104). A heat
exchange surface (122) for delivering or accepting a thermal load
from a user also defines a portion of chamber (104). A user may
directly contact heat exchange surface (122). Alternately, a user
may wear a glove or sock or take other prophylactic measures. Heat
exchange surface (122) may be provided by a member separate from
heat exchange member (106) such as by an intermediate layer of
foil, metalized Mylar or another material.
[0041] Heat exchange element (106) is preferably made of aluminum,
stainless steel or another high thermally conductive and
non-corrosive material. It may be in communication with a thermal
electric heating element such as a Peltier device, a desiccant
cooling device or an endothermic or exothermic chemical reaction to
provide a temperature variance. More preferably, however, heat
exchange member (106) is in communication with at an inlet and an
outlet (124) to accommodate a flow of perfusion liquid behind heat
exchange surface (122). Chilled or heated water may be used to
maintain the contact surface of the element at a desired
temperature. Optimally, perfusion fluid is run through a series of
switchbacks in cavity (126) between element (106) and base (114) to
ensure adequate thermal contact with the heat exchange surface
(122) and to maintain even heating or cooling by avoiding hot or
cold spots.
[0042] A rear portion of housing (102) and heat exchange member
(106) may be provided by plate (128). As depicted, this portion may
include provision for inlet and outlet (124) to heat exchange
cavity (126) and a chamber opening (130) to chamber (104). A
preferred manner of constructing seal (108) is disclosed in
connection with plate (128).
[0043] Views detailing preferred geometric aspects of seal (108)
are shown in FIGS. 4, 5 and 6. FIG. 4 shows an end-on view of seal
(108). The seal (108) having a longitudinal axis (L) includes a
chamber portion (129), a waist portion (135), and a seal portion
(137) each defining a chamber opening (131), a waist opening (136),
and a seal opening (138) respectively. The chamber portion (129) of
the seal (108) is connected to the housing (102) at the chamber
opening (130). Preferably, at least portions of seal (108) are
ovalized in form. An elliptical shape may be preferred. A circular
shape may also be used. Still, a shape having a major axis (132)
and a minor axis (134) will be preferred, at least for the waist
opening (136) of seal (108). An ovalized shape approximately
corresponds to the shape of the wrist or forearm of a user. A shape
having a major axis (132) and a minor axis (134) will also be
preferred at chamber opening (131) and seal opening (138). This
will assist in providing clearance for hand entry and exit of
module (100). It will also simplify the construction of seal
webbing (140).
[0044] Whether or not ovalized features are utilized for seal
(108), it will be shaped roughly like an hourglass. Seal (108) will
most closely resemble an hourglass if openings (131), (136) and
(138) are circular. When ovalization is applied, different
projected views of seal (108)--such as viewed in FIG. 5, for the
section taken along line A-A and in FIG. 6 for the section taken
along line B-B--display an hourglass shape.
[0045] Of course, the shapes depicted may be characterized as other
than "hourglass" forms. For instance, profiles of seal (108) may be
viewed as hyperbolic or parabolic. Further, simple radiused or
semi-circular cross-sections may be utilized in producing seal
(108). Further straightened sections may be used, especially,
between the openings (131) and (138) and waist (136).
[0046] Whatever the case, a seal with outside openings of a greater
size than that of the inside opening is to be used in module (100).
For example, the opening 131 and the seal opening 138 are greater
relative to the waist opening 136. This geometry provides for ramps
or transition sections for appendage entry and exit. These features
assist in stretching the seal interface or waist (136) sufficiently
wide to pass a hand or foot both for insertion into and removal
from module (100).
[0047] Material selection is important in providing such a seal.
Clearly, the material must be able to stretch. Further, it should
provide a substantial barrier to air flow. To meet each of these
criteria, a urethane-backed lycra available from Malden Mills
(Malden, Mass.) has proven effective. Still, it is contemplated
that other materials may be used. The material (or materials)
selected for webbing (140) preferably has a finish that does not
grip onto a user so as to complicate entry and exit from module
(100). The urethane skin of the referenced material has a satin
finish. This decreases friction with the skin and hair of a
user.
[0048] In addition to providing sufficient stretch, the seal
webbing material should also have sufficient strength to avoid
being drawn too far into cavity (104) upon the application of
vacuum. When in use, the open construction of seal (108) will
result in cavity-side webbing material exposed to partial vacuum
within chamber (104) to be forced by ambient pressure inward. This
self-inflation phenomena observed for the chamber-side of the seal
is of assistance in providing seal patency with a user. However, if
too much material bows inward, it will result in an uncomfortable
or disconcerting displacement of the user's hand or foot into the
device. Therefore, an elasticity of the seal material is selected
such that too much material does not bow inwardly when negative
pressure is applied in the chamber. A less elastic seal will not
bow inwardly as much when compared to a seal that is more elastic.
In operation, when the user inserts an appendage into the device
and the vacuum is applied, the seal will bow inwardly to reduce at
least the waist opening by an amount sufficient to contact the
appendage without uncomfortably cinching the wrist. Therefore, the
elastic seal permits sealing upon the application of a vacuum
without the use of a "hard" seal such as an inflatable bladder
cuff. Accordingly, with proper material choice, the side of seal
(108) opposite chamber (104) provides not only a transition section
for entry and exit, but also a stabilizing feature for seal
position.
[0049] Seal (108) is preferably formed by a sleeve made by
stitching two pieces of webbing material (140) together where they
are shown broken apart in the exploded view of FIG. 3, although the
invention is not so limited. By constructing the sleeve from two or
more pieces, complex shapes can be easily produced. To secure the
sleeve webbing (140) in place to form seal (108), it is folded over
rings (142) at each end as variously depicted. Then the cavity-side
ring and webbing is captured in opening (130) of plate (128). The
opposite side of seal webbing (140) is captured between outer ring
(142) and retainer member (144). Standoffs (146) or equivalent
structure space plate (128) and ring retainer (144) apart to define
the overall length of seal (108). Of course, the length of the
standoffs or seal may be varied as well as the other parameters of
seal (108) that effect fit.
[0050] In this respect, it is noted that it may be desirable to
provide a longer overall seal in some instances. Increasing overall
length provides further design flexibility with seal shape. This
may be best taken advantage of by increasing the length of waist
(134) to provide greater seal surface contact with a user. This may
beneficially reduce any undesirable constricting effects.
Furthermore, it is to be appreciated that the nature of the
material used for the seal webbing (140) may be advantageously
varied. While the noted lycra-based material is isotropic in
nature, an anisotropic material or effect may be preferred for the
webbing. This is to say that greater radial expansion of the sleeve
may be desirable, whereas longitudinal compliance may not be. By
reducing compliance along the axis of the sleeve relative to a
radial or lateral component, it will tend to be drawn into chamber
(104) to a lesser degree upon the application of vacuum. For a very
high-stretch material, this will allow for smaller seal openings to
fit the same population (since they can still stretch webbing (140)
laterally and have it return sufficiently to form a desired seal),
without forfeiting the full set of advantages that the two-sided
seal described offers.
[0051] Such an anisotropic effect may be achieved in a number of
ways. It may be accomplished by providing longitudinal
reinforcement member(s) associated with the webbing. They may be
incorporated through braiding techniques, by bonding/affixing
stiffener(s) to the sleeve surface or by other means as would be
apparent to one with skill in the art.
[0052] The seal (108) includes a relaxed position defined by the
fact that no portion of the mammal is contact with the seal (108).
When the portion of the mammal is inserted through the seal (108),
at least the waist opening (136) will expand under force of the
moving portion of the mammal as it is being inserted. Hence, the
elastic material of the seal provides a waist opening (136) that
varies in size with the insertion of the portion of the mammal and
substantially conforms to seal against the portion of the mammal.
The waist opening (136), when in a relaxed position, may be sized
smaller than the expected size of the portion of the mammal to pass
therethrough, or alternatively, the waist opening (136) may be
miniscule. The invention is not limited to a variable waist opening
(136). The seal opening (138) may likewise be variable as are
portions between the waist opening (136) and the chamber opening
(131) and the seal opening (138). Overall, at least a portion of
the seal (108) includes an elastic element to bias the seal (108)
against the portion of the mammal. Hence, the seal (108) forms a
variable opening adapted to substantially conform against the
mammal to contact or seal a portion of the mammal inside the
chamber (104).
[0053] The seal (108) includes a flexible wall member that provides
substantial contact sealing against at least a portion of the
external surface of the mammal while accommodating motion of the
portion of the mammal wherein the motion of the mammal is in a
direction lateral to the longitudinal axis (L) of the seal (108).
For example, when a hand is inserted into the seal (108), and if
the middle finger first breaches the seal opening (138), it may do
so with or without forcing expansion of the seal opening (138).
Next, the middle finger, for example, may breach the waist opening
(136) and it may do so with or without forcing expansion of the
waist opening (136). However, once the widest portion of the hand
contacts the seal (108), the seal (108) will surely expand and
circumferentially conform to seal against the hand. Any one portion
or at least the waist portion (135) will engage at least a portion
of the external boundary of the portion of the mammal. When the
hand is positioned within the chamber, another portion of the
mammal, for example, the wrist will rest within the seal (108). Of
course, with the wrist substantially aligned with the longitudinal
axis (L) of the seal (108), the seal (108) will preferably engage
the entire boundary of the external surface of that portion of the
wrist. The seal (108) is no longer in a relaxed position, but in
what may be called an active engaged position.
[0054] The seal (108) is designed to substantially accommodate
movement of the portion of the mammal yet substantially prevent
leakage of vacuum fluid from the chamber (104). To use the same
example of a hand, the seal (108) accommodates motion of the hand
that is eccentric or lateral to the longitudinal axis (L). Hence,
the seal (108) is said to be laterally deflectable with motion of
the portion of the mammal relative to the rest of the module (100).
When, for example, motion of the portion of the mammal, the wrist,
for example, is substantially lateral relative to the longitudinal
axis (L), a portion of the seal will be overly compressed on one
side whereas the opposing side will tend to approach the relaxed
position, thereby, providing an avenue for air leakage
therethrough. This feature is advantageous with respect to
providing a seal design that is comfortable for the user.
[0055] A "soft" seal as described herein is characterized as
providing an approximate or imperfect seal at a user/seal interface
while accommodating substantial eccentricities of the portion of
the mammal received. Such a seal may be more compliant in its
interface with a user. Indeed, in response to user movement, such a
seal may leak or pass some air at the user/seal interface as
described above. In a negative-pressure system designed for use
with a soft seal, a regulator or another feedback mechanism/routine
will cause a vacuum pump, generator, fan or any such other
mechanism capable of drawing a vacuum to respond and evacuate such
air as necessary to stabilize the pressure within the chamber,
returning it to the desired level. Active control of vacuum
pressure in real-time or at predetermined intervals in conjunction
with a "soft" seal provides a significant advantage over a "hard"
seal system that relies on simply pulling a vacuum with the hopes
of maintaining the same.
[0056] Vacuum regulation in the application of body temperature
regulation is very important. A negative pressure environment is
generated within the module to distend the blood vessels of the
appendage located inside the module. This distension dilates the
blood vessels, which allows higher bloodflow rates, which is
advantageous for delivery of energy from the appendage to the rest
of the body or from the body to the appendage for dissipation into
the module. Furthermore, the distension of blood vessels pools more
blood volume in the region that is in thermal communication with
the module.
[0057] First, a set-point for the desired level of negative
pressure within the chamber is selected. This set-point level of
negative pressure within the negative pressure chamber is then
established and maintained by a control system. The control system
is in communication with a vacuum pump that is in communication
with the negative pressure chamber for withdrawing air therefrom.
The control system monitors the pressure within the chamber and
adjusts a valve to throttle it accordingly until the pressure
within the chamber is re-established at the selected set-point.
[0058] As described above, the "soft" seal is designed such that
leakage of air at the seal is possible in order to avoid a
tourniquet effect at the wrist. The negative pressure control
system is adapted to maintain a negative pressure environment at
the set-point pressure despite a great variability in leaks. The
variability of leaks arises, for example, when an appendage is
displaced by varying distances from the longitudinal axis and by
the time period of such displacements. Also, varying appendage
geometries of different or same users may create a variability of
leaks. Simply repositioning the appendage can create a very large,
small, or no leak at all. Uniquely, the allowability of leaks is
inherent in the seal design of the present invention. This
allowability of leaks is intended to comfortably accommodate a
user. The negative pressure control system is adapted to maintain a
functional negative pressure for optimum heat exchange with the
appendage that involves maintaining a constant level of vacuum
throughout a wide range of leaks having varying leak flow rates.
For example, if there is a large leak, the vacuum regulator must
draw air from the chamber at a very high flow rate in a short
amount of time to re-establish the set-point pressure without
over-drawing. The control system monitors the leak flow rate and
responds to the leak flow rate with an equivalent vacuum draw rate
by throttling the valve accordingly.
[0059] Regardless of the particulars of seal construction and
whether it is utilized to provide a "hard" or "soft" user
interface, the dual-sided seal disclosed provides a superior manner
of carrying out the methodology noted above. Though a "soft"
two-sided seal as shown in the figures is preferred for its
elegance in approach and proven effectiveness, a "hard" or more
complex "soft" seal approach might sometimes be desired.
[0060] In order to utilize the dual-sided seal in a "hard"
approach, supplemental forcing means may be provided to apply
pressure around seal waist (134). Mechanical means such as at least
one of a strap, Velcro.TM., belt or cinch may be used. Alternately
an inflatable cuff or bladder portions around the periphery of the
seal may be employed. In one variation, the "soft" seal (108) is
designed to have a waist opening (136) that is smaller than the
seal opening (138) and chamber opening (131). Expansion means to
expand or pull the seal open for insertion of the appendage is
connected to the seal. The expansion means, for example, include
cordage, mechanical linkage and any other expansion means known to
a person skilled in the art. In one variation, the expansion means
includes stop means to keep the opening constant for tailored
sealing with a particular user. For example, a user expands the
seal using the expansion means until insertion of the hand is easy
and comfortable and a seal is properly established without undue
constriction. Then, the user can engage the stop means to prevent
the seal from contracting back to its initial opening and creating
an uncomfortable tourniquet effect. Examples of stop means include
any device or mechanical linkage that limits the travel of the
expansion and contraction of the seal and those known to one
skilled in the art.
[0061] While the system complexity will increase due to provision
for providing the supplemental pressure and controlling it by
either automated or manual means, certain potential advantages
arise. It may enable a single-evacuation procedure for chamber
(104) rather than relying on constant or periodic vacuum
replenishment. It may also provide greater design flexibility for
seal (108). Particularly, by providing another variable to utilize
in design decisions, a lesser emphasis may be placed on webbing
material choice or opening sizing since the supplemental forcing
capacity may be used to shape the seal as desired in use. Further,
it may enable fitting the seal (108) to a wider range of a populace
for a given configuration of hard elements, such as those that
make-up seal frame (110).
[0062] Supplemental forcing or seal shaping means may also be used
to produce a more complex "soft" seal than that described above. As
with a "hard" seal approach, this would open design and fit
possibilities. Forcing or seal shaping parameters may, again, be
controlled manually or automatically. Except, in a complex "soft"
seal, the control of pressure applied to waist (134) is gauged to
provide a compliant feel or fit. Since the application of pressure
on the seal interface with the user may be the only difference
between a complex "soft" seal approach and a "hard" seal approach
utilizing the dual-sided configuration, the same apparatus may be
configured to function in either manner, for instance, by providing
variable pressure control.
[0063] In one variation, the seal (108) is adapted such that one
end of the seal (108) is rotatable relative to the other end of the
seal (108) to reduce the opening of the seal. For example, ring
(142) carrying the chamber portion (129) is adapted to rotate
relative (128) to ring (144). Ring (144) may remain stationary or
rotate by a lesser degree such that there is relative movement of
the chamber portion (129) of the seal (108) with respect to the
seal portion (137) of the seal (108). Of course ring (142) may
remain stationary or rotate by a lesser degree such that there is
relative movement of the chamber portion (129) with respect to the
seal portion (137). Rotation of one end of the seal (108) relative
to the other end of the seal (108) constricts the seal (108)
inwardly to reduce at least one of the openings (131), (136) and
(138). Twisting the seal can finely control the degree to which the
openings in the seal are reduced or expanded.
[0064] When twisted, folds in the seal (108) may be created. In one
variation, to avoid creating folds, the seal (108) is inserted into
a cylindrical sheath or sock (not shown). The sheath encompasses
the seal (108) and is substantially coaxial with respect to the
seal (108). The sheath is made of similar material as the seal
(108) or it can be made of any suitable material. The sheath is
supported by the seal frame or by a sheath frame. In this
variation, the seal (108) is not rotatable. The sheath is adapted
such that one end of the sheath is rotatable relative to the other
end of the sheath. When one end of the sheath rotates relative to
the other end of the sheath, the sheath opening is reduced.
Reduction of the sheath opening will gently push against the seal
(108) to reduce the opening of the seal without generating folds in
the seal (108). Folds are created in the twisted sheath and not in
the seal (108). The sheath is easily adapted into the frame
elements of the device to provide a complex "soft" seal
variation.
[0065] Referring now to FIGS. 7-9, there is depicted another
variation of a negative pressure thermal exchange module (200). The
module (200) includes a housing (202) and a seal cartridge (204).
The seal cartridge (204) is removably connected to the housing
(202).
[0066] The housing (202) includes a cover (206), a base (208), a
plate (212), and a heat exchange element (210) having a heat
exchange surface (222). The cover (206) is connected to the base
(208) and plate (212) to define a chamber (214) for receiving a
portion of a mammal via a chamber opening (216) defined in the
plate (212). The chamber (214) is defined between the heat exchange
surface (222) and the cover (206). As depicted, the cover (206) is
made of transparent plastic material; however, the invention is not
so limited and any suitable material, transparent or not, is within
the scope of the present invention.
[0067] The base (208) includes a heat exchange cavity (218).
Thermal exchange media (not shown) is received within the heat
exchange cavity (218) via inlet and outlet ports (not shown) such
that the media is communication with an element (not shown) that is
external to the module (200) such as a thermal electric heating
element such as a Peltier device, a desiccant cooling device or an
endothermic or exothermic chemical reaction to provide a
temperature variance. As shown, the base (208) includes pathways
(220) in the form of switchbacks for the media to ensure adequate
thermal contact with the heat exchange element (210) and to
maintain even heating and cooling.
[0068] The heat exchange element (210) is in thermal communication
with the heat exchange surface (222) and in thermal communication
with the media received in the pathways (220). The heat exchange
element (210) is in thermal communication with the heating and/or
cooling element that is preferably external to the device. The heat
exchange element (210) is preferably made of aluminum or another
highly conductive, non-corrosive material. The heat exchange
element (210) includes a surface (222) with which the mammalian
appendage comes into contact. The contact surface (222), in one
variation, is separable from the heat exchange element (210). One
advantage of the separability of the heat exchange surface (222)
from the heat exchange element (210) is to dispose of a used or
soiled surface for the replacement of a new one. Another advantage
of a separable heat exchange surface (222) is to have the heat
exchange element external to the module (200). Furthermore, the
heat exchange element (210) is shown to be convex with respect to
inside the chamber (214). Of course, the contact surface (222)
substantially conforms to the curvature of the heat exchange
element (210). Aside from its aesthetic appeal and ornamental
quality, the curvature of the heat exchange element (214) provides
for a naturally curved surface for an appendage such as a human
hand to comfortably rest in a relaxed position on top of the
surface (222).
[0069] The plate (212) is connected to the rear portion of the
housing (202) such that its chamber opening (216) provides passage
to the chamber (214). The chamber opening (216) is suitably sized
to receive a wide range of appendage sizes. The plate (212) also
includes additional ports. For example, in one variation, a
pressure port (224) is formed in the plate (212) for the attachment
of a pressure gauge (226). Also, ports (228 for vacuum induction
are also be formed in the plate (212) in one variation. Of course,
ports for receiving various fasteners (230) are also provided for
fastening the seal cartridge (204).
[0070] The seal cartridge (204) will now be described. The seal
cartridge (204) forms an element that is separable from the housing
(202). The seal cartridge (204) includes a seal (232) and seal
frame elements (234) supporting the seal (232) on both sides. The
seal (232) is the same seal as that described above with respect to
FIGS. 1 through 6. The frame elements (234) include a first frame
element (236) that is adapted for connecting with the plate (212).
The first frame element (236) is spaced apart with standoffs (238)
from a second frame element (240). The first frame element (236)
includes a ring (242), a first retaining member (244) and a second
retaining member (246). The second frame element (240) includes a
ring (248), a first retaining member (250) and a second retaining
member (252). To secure the seal (232), one side of the seal (232)
is folded over ring (242) and captured between the first and second
retaining members (244), (246) of the first frame element (236).
The other end of the seal (232) is folded over ring (248) and
likewise captured between the first and second retaining members
(250), (252) of the second frame element (240). Standoffs (238) or
equivalent structure space the first and second frame elements
(236), (240) apart to define the overall length of the seal (232).
Of course, the length of the standoffs (238) or seal (232) are
varied as well as other parameters of the seal (232) that affect
fit.
[0071] The seal cartridge (204) is removably connected to the
housing (202) with fasteners (254). Alternative fastening means are
within the scope of the invention and are known to one skilled in
the art. For example, the seal cartridge (204) can be rotatably
connected or attached in a snap-fit engagement. One advantage
associated with the seal cartridge (204) is that different users
can have personal seal cartridges (204) that are customized for
differently sized appendages, yet operably attachable with one or
more housings (202). Personal seal cartridges (204) are also
adjustable with respect to the individual requirements relating
tolerance, ease, or speed of insertion. For example, an unconscious
patient whose temperature is being regulated is not available to
actively participate in positioning and insertion into the device.
Nonetheless, use of a personal seal-cartridge that is appropriately
selected would allow efficient use of the device in such a
scenario. In another example, an athlete may be more concerned with
speed of insertion, or be encumbered with layers of clothing and
therefore would require a personalized seal cartridge that is more
accommodating with respect to those factors.
[0072] As mentioned above, the device is adapted for the insertion
of a mammalian appendage such as a hand; however, the invention is
not so limited and the device may be designed to accommodate an
appropriate appendage. For example, as shown in FIG. 10, there is
depicted a negative pressure thermal exchange module (300) that is
shaped to accommodate a human foot. The module (300) includes a
housing (302) and a seal cartridge (304). The seal cartridge (304)
is configured as described above with respect to FIGS. 7-9 or FIGS.
1-6 and may be removably attached via fasteners (305) or other
means.
[0073] Similar to the variations described above, the housing (302)
includes a cover(306), a base (308), a heat exchange element (310)
and a plate (312). The cover (306) is connected to the base (308)
and plate (312) to define a chamber (314) for receiving the foot.
Entry into the chamber (314) is provided in the top of the module
instead of through an opening in the plate (312). The heat exchange
element (310) includes a convex heat exchange surface (316) when
viewed from inside the chamber (314) to comfortably accommodate the
natural curvature of the foot received therein. All components are
similar to the corresponding components of the module described
above as is readily apparent to one skilled in the art.
[0074] Referring now to FIGS. 11-13, there is depicted another
variation of a negative pressure thermal exchange module (400). The
module (400) includes a cover (402) pivotably connected to a base
(404). The cover (402) includes a first end (406) and a second end
(408). A perimeter (409) encompasses a surface (410). The surface
(410) is shaped to accommodate an appendage. As shown, the surface
(410) is curved or concave. The cover (402) includes an opening
portion (412). As shown in FIG. 11, the opening portion (412) is
formed in the perimeter (409). The opening portion (412) is a
curved portion that is adapted to receive at least a portion of a
seal (413) and a portion of an appendage such as a wrist of a human
hand (407) as shown in FIG. 13. In one variation, the seal (413) is
a "hard" seal. Alternatively, the seal (413) is a soft seal of the
type described above.
[0075] The base (404) includes a first end (414) and a second end
(416). A perimeter (420) encompasses a chamber surface (418) that
includes a heat exchange surface (422). The base perimeter (420)
includes an opening portion (424). The opening portion (424) is a
curved portion that is adapted to receive at least a portion or
second half of a seal (426). In one variation, the seal (426) is a
"hard" seal. Alternatively, the seal (426) is a soft seal of the
type described above. The module (400) is preferably formed of
molded plastic polycarbonate. The heat exchange surface (422) is
made of thermally conductive material such as metallic foil or a
thin film of thermally conductive plastic.
[0076] In one variation, the first end (406) of the cover (402) is
connected to the first end (414) of the base (404) such that the
cover (402) is hinged and is rotatable between at least a
substantially open first position and at least a substantially
closed second position. A substantially open position is depicted
in FIG. 11 and a substantially closed position is depicted in FIGS.
12 and 13. When in the open position, an appendage, such as the
wrist of a human (407) hand is rested on the seal (426) that is
securely disposed within the opening portion (424) of the base
(404). The hand (407) comfortably rests and is in thermal
communication with the heat exchange surface (422). The cover (402)
is then rotated about its first end (406) to a substantially closed
position. When in the closed position, the perimeter (409) of the
cover (402) substantially aligns with the perimeter (420) of the
base (404) and is attached thereto. The perimeter (409) of the
cover (402) is connected to the perimeter (420) of the base (404)
with an adhesive layer (430), for example, located on either
perimeter (409), (420). A protective release layer (not shown) is
removed to expose the adhesive layer (430) therebeneath so that the
adhesive layer (430) can seal the cover (402) to the base (404) in
order to maintain a substantially leak-proof negative pressure
environment. Alternatively or in conjunction with the adhesive
layer (430), the cover (402) is attached to the base (404) in a
snap-fit engagement or by employing a variety of fasteners
(432).
[0077] When in the closed position, the seal-receiving portion
(412) of the cover (402) substantially aligns with the
seal-receiving portion (424) of the base (404) to contact an
appendage located therebetween and to substantially prevent the
leakage of air across the seal. Surfaces (410) and (418) also
substantially align to form a chamber (428) for receiving the
appendage. Ports (not shown) for supplying a negative pressure
environment are formed in either the cover (402) or base (404) and
in communication with the chamber (428).
[0078] The module (400) is designed to be separable from a heat
exchange element (434). For example, with the hand (407) positioned
inside the chamber (428), the module (400) is placed over a heat
exchange element (434) such that the heat exchange element (434) is
in thermal communication with the heat exchange surface (422) and
in thermal communication with the appendage (407) inside the
chamber (428). The heat exchange element (434) is made from
aluminum, stainless steel, or other highly thermally conductive and
non-corrosive material. It may be in communication with a thermal
electric heating element such as a Peltier device, a desiccant
cooling device or an endothermic or exothermic chemical reaction to
provide a temperature variance.
[0079] The heat exchange surface (422) is shaped to conform to the
general aspects of the appendage inserted within the chamber (428).
Furthermore, the heat exchange element (434) is shaped to
substantially conform to the heat exchange surface (422). In one
variation, the heat exchange surface (422) is flexible and made
from a material that is easily conformable to the appendage (407)
such as metallic foil. As a vacuum is generated inside the chamber
(428), a flexible heat exchange surface (422) is drawn in contact
with the appendage (407). The module (400) is placed over the heat
exchange element (434) such that the heat exchange element (434) is
received outside of the heat exchange surface (422). In one
variation, the heat exchange surface (422) is substantially concave
with respect to the outside of the module (400) and the outer
surface of the heat exchange element (434) is substantially convex
such that when the module (400) is placed over the heat exchange
element (434) it is substantially conformingly received within the
outer concavity of the heat exchange surface (422). The invention
is not so limited and irrespective of the concavity of either the
heat exchange surface (422) or the heat exchange element (434), the
surface (422) and the element (434) have generally complementary
shapes so as to place the surface (422) in closer thermal
communication with the element (434). The module (400) is adapted
such that the heat exchange element (434) can be secured to the
module (400). For example, the module (400) can be secured to the
heat exchange element (434) in a snap-fit engagement or with
fasteners. The module (400) is easily separated from the thermal
exchange element (434) making the module (400) easily portable with
the patient as the patient is moved from bed to bed, for example,
with separate heat exchange elements (434) awaiting the patient in
different locations. The variation of FIGS. 11-13, is a disposable
version most suitable for the hospital environment where individual
modules are desired for sanitary purposes.
[0080] While the present invention has been described with
reference to one or more particular variations, those skilled in
the art will recognize that many changes may be made thereto
without departing from the spirit and scope of the present
invention. Each of these embodiments and obvious variations thereof
are contemplated as falling within the spirit and scope of the
claimed invention, which is set forth in the following claims.
* * * * *