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TECHNICAL FIELD
The present invention relates generally to therapeutic treatment of the
body. The present invention particularly relates to an apparatus for
treating bodily injuries and ailments by cooling or heating the affected
body surface. The present invention more particularly, though not
exclusively, relates to an apparatus for continuously circulating a
nonambient temperature fluid across a desired treatment surface of the
body.
BACKGROUND OF THE INVENTION
Bodily injuries and ailments are commonly treated by applying a nonambient
temperature material to the affected area of the body. For example, a low
temperature material, typically applied in the form of ice or a cold
liquid, advantageously inhibits swelling in the region of the injury. A
high temperature material, typically applied in the form of hot water or
an active heating element, advantageously reduces pain and promotes
healing. A number of splint devices are known in the art for applying
nonambient temperature materials to injured or otherwise ailing areas of
the body as evidenced by U.S. Pat. Nos. 3,548,819 to Davis et al;
3,901,225 to Sconce; and 4,706,658 to Cronin. One disadvantage of such
devices is that the low temperature materials become warmer as they remain
in contact with the body during treatment and the body transfers heat
thereto. Conversely, high temperature materials become cooler as they
transfer heat to the body. This disadvantage can be remedied by
periodically replacing the nonambient temperature materials. However,
constant replenishment of these materials is cumbersome and inconvenient,
and results in periodic treatment temperature fluctuations.
In response to this problem, a number of systems have been developed for
continuously circulating a cooling fluid from a low temperature reservoir
to a desired body location. Such systems are typified by U.S. Pat. Nos.
2,726,658 to Chessey; 3,683,902 to Artemenko et al; and 4,962,761 to
Golden. These systems are noteworthy in that they are relatively complex
and thus, costly to manufacture and maintain, as well as being somewhat
difficult to operate. Accordingly, the systems are not particularly
practical for use among the general population.
Given the proliferation of sports and leisure activities and the
proliferation of injuries associated therewith, a widespread need exists
for a practical therapeutic nonambient temperature treatment device. In
particular, a need exists for a device which circulates a nonambient
temperature fluid across a desired surface of the body to provide
therapeutic treatment thereto, wherein the device is relatively simple to
operate and inexpensive to produce and maintain. As such a therapeutic
nonambient temperature treatment device is needed which can be employed in
the home or in the workplace to provide cost-effective treatment which
does not significantly disrupt the daily schedule of the user.
SUMMARY OF THE INVENTION
The present invention is a device for therapeutically treating a desired
region of a patient's body with a nonambient temperature fluid, i.e., a
cooling fluid or a heating fluid, which is circulated through a pad placed
over the desired region. The pad encloses a continuous tortuous flowpath
for the nonambient temperature fluid which has a fluid inlet port at its
entrance and a fluid outlet port at its exit. Corresponding fluid inlet
and outlet lines are provided, each having an end connected to the inlet
and outlet ports respectively. The opposite ends of the fluid inlet and
outlet lines are placed in a nonambient temperature reservoir containing
an excess of nonambient temperature fluid, thereby providing fluid
communication between the pad and the reservoir, and enabling circulation
of the fluid therebetween.
The end of the inlet line situated in the reservoir has a pump positioned
thereon which is submersed in the fluid to provide a drive mechanism for
the fluid. Thus, fluid circulation is effected by pumping the fluid from
the reservoir through the inlet line into the pad via the inlet port. The
fluid follows a tortuous flowpath through the pad to the outlet port where
it is discharged back to the reservoir through the outlet line.
To provide for temperature control of the pad, an in-line valve is
positioned in either the inlet or outlet line, but preferably the outlet
line. The valve is an adjustable flow restrictor, which enables regulation
of the fluid flow rate through the system. In the case of a cooling fluid,
by closing the valve to reduce the flow rate of fluid through the system,
the fluid residence time in the pad increases, correspondingly increasing
the temperature in the pad due to heat transfer effects from the body. By
opening the valve to increase the flow rate, the cooling fluid residence
time in the pad decreases causing a temperature decrease therein.
Conversely, in the case of a heating fluid, closing the valve decreases
the temperature in the pad, while opening the valve increases the
temperature in the pad. An in-line temperature monitor is further
provided, preferably in the outlet line, to enable operator monitoring of
the fluid temperature in the pad. The in-line valve may accordingly be
adjusted in response to temperature readings from the monitor.
The temperature monitor and flow restriction valve may be enclosed within a
unitary control housing. A manual valve control knob and a temperature
display are operator accessible on the exterior of the housing. An
electrical connector can also be provided on the exterior of the housing
which is connected to an internal power line extending to the pump. The
connector enables electrical connection of the pump to an external power
source, such as a battery or a conventional wall outlet, via an external
power line. Alternatively, the device may have its own internal power
source in the form of a battery.
A joint comprising a pair of inlet and outlet couplings is provided to
connect the fluid inlet and outlet lines and the fluid inlet and outlet
ports, respectively. The joint enables dissociation of the pad from the
lines and allows interchangability or removal of the pad for storage or
cleaning. An insulative sheath may be provided along the length of the
inlet and outlet lines which, in association with the control housing,
fully encloses the lines within a single tubular unit for ease of handling
and for temperature insulation of the lines. The internal power line may
further be included within the tubular unit extending from the housing to
the pump.
The device as described above is designed to be portable to the extent it
is readily transportable for set up and use at varied locations. The
nonambient temperature reservoir may be structurally dissociable from the
remainder of the device so that it need not be transported with the device
to each location of use, thereby enhancing the portability of the device.
A conventional bucket or insulated passive cooler may be used as the
reservoir, both of which are commonly available at most locations. One
need only fill the reservoir with a nonambient fluid, such as ice water or
hot water, and connect the power source to render the device operable. If
the device is used for cooling and the reservoir becomes too warm, it can
be restored to a low temperature simply by adding ice as desired.
Likewise, if the device is used for heating and the reservoir becomes too
cool, hot water can be added.
The novel features of this invention, as well as the invention itself, both
as to its structure and its operation, will be best understood from the
accompanying drawings, taken in conjunction with the accompanying
description, in which similar reference characters refer to similar parts,
and in which:
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of the fluid circulation system of the present
invention;
FIG. 2 is a view of the interior of the pad in the fluid circulation system
of the present invention; and
FIG. 3 is an exploded view of the pump unit in the fluid circulation system
of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
Referring initially to FIG. 1, the fluid circulation system of the present
invention is shown and generally designated as 10. For purposes of
illustration, FIG. shows a low temperature embodiment of the fluid
circulation system of the present invention which is generally designated
as 10. It is understood, however, that the description of system 10 as
shown and set forth below applies generally to high temperature
embodiments of the present invention as well.
Referring to FIG. 1, system 10 comprises a cooling pad 12 positionable on
the body of a patient at the point where therapeutic low temperature
treatment is desired. Pad 12 is shown here on the arm 14, but it is
apparent that pad 12 can be positioned substantially anywhere on the body
where treatment is desired. Pad 12 is preferably fabricated from a pliable
polyurethane film such that it is at least somewhat conformable to the
body contours of the patient. To facilitate conformance, pad 12 has a
plurality of seams 15 formed therein.
Pad 12 has a fluid inlet port 16 and a fluid outlet port 18 which are
connected to a fluid inlet line 20 and a fluid outlet line 22,
respectively. Lines 20, 22 and ports 16, 18 have substantially the same
inside diameter of about 3/16 inches and are connected at joint 24 having
two snap-action locking couplings 26 and 28 having lock release buttons 27
and 29. More specifically, fluid inlet port 16 is connected to the
proximal end 20a of fluid inlet line 20 across inlet coupling 26, and
fluid outlet port 18 is connected to the proximal end 22a of fluid outlet
line 22 across outlet coupling 28.
Each coupling 26, 28 comprises a male connector on the port side of the
coupling and a female connector on the line side of the coupling. The male
connectors of couplings 26, 28 are housed together in a unitary molded
mount, and the female connectors are similarly housed in a unitary mount
to facilitate simultaneous connection of couplings 26, 28. Couplings 26,
28 are further provided with an internal shut off valve which
automatically closes lines 20, 22 and ports 16, 18 when the couplings are
disconnected.
System 10 further comprises a pumping unit 30 and a control unit 32.
Pumping unit 30 is connected to fluid inlet and outlet lines 20, 22 at
distal ends 20b, 22b thereof. Control unit 32 is integral with lines 20,
22, and has a housing 34 having a manually adjustable valve control knob
36 and a temperature display 38 mounted thereon. Housing 34 also has an
electrical connector 40 mounted thereon which enables an electrical
connection between pumping unit 30 and an external power source.
Specifically, electrical connection is provided by an external power line
42 which is connected at one end to an internal power line 44 (shown in
FIG. 3) across electrical connector 40 and which is connected at the other
end to a conventional ac current wall plug 46 across a transformer 48.
Internal power line 44 is positioned within a waterproof conduit 45 which
extends from control unit 32 to pumping unit 30.
System 10, as shown, is reliant on an external ac current power source
which limits its portability. As an alternate external power source to
conventional ac current, a portable external battery pack (not shown) may
be provided consisting of disposable dry D-cell batteries or rechargeable
batteries. External power for system 10 may also be obtained from an
automobile battery by providing an adaptor line (not shown) from connector
40 which fits into an automobile cigarette lighter outlet.
System 10 may be rendered more portable by eliminating electrical connector
40 external power cord 42, and transformer 48 and replacing them with an
internal power pack (not shown) in control unit 32 which is connected to
internal power line 44. Alternatively, electrical connector 40, external
power cord 42, and transformer 48 may be retained in parallel with an
internal power pack to provide system 10 with the capability of utilizing
either an external or internal power source.
An insulative sheath 50 is provided over cooling fluid inlet and outlet
lines 20, 22 and conduit 45 which, in conjunction with control unit
housing 32, forms a substantially water-proof tubular unit 52 containing
lines 20, 22 and conduit 45 from junction 24 to pump unit 30. Sheath 50 as
well as lines 20, 22 and conduit 45 are formed from flexible materials
which render tubular unit 52 fully flexible. Sheath 50 has a strong and
resilient plastic exterior skin and an insulating foam interior which
minimizes heat exchange between lines 20, 22 and the ambient atmosphere
and further prevents condensate formation on the exterior of lines 20, 22.
A flexible sheath 54 having a similar composition may also be provided
over inlet and outlet ports 16, 18 extending between junction 24 and pad
12 to form a tubular unit 56 for ports 16, 18.
System 10 has a low temperature reservoir 58 which as shown is structurally
independent of the remainder of system 10 such that pump unit 30 and
distal ends 20b, 22b of lines 20a, 22a are freely positionable within
reservoir 58. Alternatively, reservoir 58 can be structurally integral
with system 10 by connecting line 20, 22 thereto. Reservoir 58 may be
substantially any externally-accessible hollow fluid container, such as a
bucket or a tub, although it is preferably an insulated container, such as
a conventional insulated picnic cooler having a cover (not shown) for
maintaining the low temperature therein. Cooling fluid 60, which is a
fluid cooled below ambient room temperature and preferably ice water, is
retained within reservoir 58.
FIG. 2 shows the interior baffle pattern of cooling pad 12, wherein the
polyurethane outer shell of pad 12 has been removed for purposes of
illustration. Pad 12 contains a plurality of baffles 62 which are arranged
to provide a tortuous flowpath 64 for cooling fluid 60 entering pad 12 via
inlet port 16, and exiting pad 12 via outlet port 18. It is noted that
baffles 62 engage the outer shell of pad 12 both at their tops and bottoms
to prevent short-circuiting of baffles 62, thereby forcing cooling fluid
60 to flow around baffles 62 in a tortuous manner.
FIG. 3 shows pump unit 30 in detail. Pump unit 30 comprises a pump housing
66 having a top portion 66a and a bottom portion 66b which are held
together by screws 68 fitting into screw holes 70. Top housing portion 66a
has a pump inlet port 72 which is perforated to allow fresh cooling fluid
60 to pass therethrough from reservoir 58, while blocking large solid
particles, such as crushed ice, from passing therethrough. Top housing
portion 66a also has an opening 74 formed therein to receive tubular unit
52 containing inlet and outlet lines 20, 22 and conduit 45. Bottom housing
portion 66b has a pump outlet port 76 which receives cooling fluid from
pad 12 via outlet line 22 and discharges it to reservoir 58.
Internal to housing 66 are upper plate 78a and lower plate 78b. Upper plate
78a has a nozzle so formed therein which provides fluid communication
between distal end of inlet line 20b and pumping chamber 82. The space
between plates 78a and 78b define chamber 82. Upper plate 78a also has a
cooling fluid inlet passageway 84, outlet line opening 86, and power line
opening 88 formed therethrough. Lower plate 78b has a nozzle 90 formed
therein which provides fluid communication between distal end of outlet
line 22b and pump outlet port 76. Lower plate 78b is further provided with
a nipple 92 through which line 45 passes to pump motor 94 disposed within
bottom housing portion 66b. Lower plate 78b is water-tight to prevent
intrusion of water into motor 94. Pump motor 94 has a drive shaft 96
extending into pumping chamber 82 via shaft opening 98 formed through
lower plate 78b. Shaft 96 connects to an impeller blade 100 disposed
within chamber 82.
METHOD OF OPERATION
The fluid circulation system 10 of the present invention is operated by
filling low temperature reservoir 58 with ice water 60, which is at a
temperature approaching the freezing point of water, and covering
reservoir 58 to maintain the fluid temperature therein. With joint 24
secured, pad 12 is placed on the skin of the patient at the point on the
body where therapeutic treatment is desired. An additional padding
material, such as a soft cloth, may be placed on the skin between the
pliable surface of pad 12 and the skin for the comfort of the patient.
Pump unit 30 is submerged in the ice water 60 and external power line 42 is
connected to a power source to activate the pump motor 94. Fresh ice water
60 is drawn from reservoir 58 into pumping chamber 82 and driven by
impeller blade 100 through inlet line 20 and inlet port 16 into pad 12.
The ice water travels the entirety of flowpath 64 and exits pad 12 via
outlet port 18. The ice water is returned to reservoir 58 via outlet line
22 and pump outlet port 76.
This fluid circulation cycle is performed continuously for the duration of
the desired treatment period. Temperature control of pad 12 during the
circulation cycle is achieved by manually adjusting a conventional flow
restrictor valve, which is preferably integral with control unit 32 and
positioned across outlet line 22. The valve is adjusted by means of valve
control knob 36 on control unit 32. By turning knob 36 in a direction to
restrict flow through line 22, the temperature of pad 12 is increased, and
conversely by turning knob 36 in the opposite direction to increase flow
through line 22, the temperature of pad 12 is decreased. If the ice in
reservoir 58 becomes depleted, additional amounts of ice may be added as
needed. The valve of control unit 32 further acts to regulate the back
pressure in system 10 as a function of the size of the valve opening.
Temperature control is facilitated by the temperature display 38 on the
control unit 32 which is in communication with a temperature measuring
means. The temperature measuring means and display 38 are preferably
provided in the form of a conventional liquid thermometer which is
positioned in outlet line 22. Termination of the circulation cycle is
enabled simply by disconnecting the external power line 42 from the power
source.
The high temperature embodiment of system 10 is primarily distinguishable
from the low temperature embodiment described above in that a heated fluid
is substituted for the cooling fluid. The heated fluid is preferably water
which is heated to a temperature above room temperature, i.e., exceeding
ambient. The temperature of the pad containing the heated fluid may be
decreased by partially closing the valve across the outlet line to
diminish flow therethrough, while the temperature of the pad may be
increased by opening the valve to increase the flow.
While the particular Therapeutic Nonambient Temperature Fluid Circulation
System as herein shown and disclosed in detail is fully capable of
obtaining the objects and providing the advantages herein before stated,
it is to be understood that it is merely illustrative of the presently
preferred embodiments of the invention and that no limitations are
intended to the details of construction or design herein shown other than
as described in the appended claims.
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