US 3327713 A
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Description (OCR text may contain errors)
June 27; 1967 w. Emus 3,327,713
PORTABLE THERMOEL-ECTRIC HYPOTHERMIA DEVICE Filed June 18, 1964 INVENTOR. WILLIAM EIDUS BY cfdpwe ATTORNEY United States Patent 3,327,713 PORTABLE THERMOELECTRIC HYPOTHERMIA DEVICE William Eidus, 1 Bonnie Court, Spring Valley, N.Y. 10977 Filed June 18, 1964, Ser. No. 376,096 7 Claims. (Cl. 128-399) ABSTRACT OF THE DISCLOSURE A portable hypothermia instrument including an electrically-energized themocouple assembly utilizing the Peltier effect for producing heating at one surface thereof and cooling at the opposite surface thereof, interchangeable and replaceable heat dissipating members removably attachable to one of said surfaces in heat-exchange relationship therewith, and a plurality of applicator members shaped for contact with various portions of a patients body and removably attachable to the opposite surface of said thermocouple assembly.
In the theropeutic treatment of persons, for example patients in hospitals or in doctors ofiices, direct cooling application is often required to reduce pain, retard swelling or edema due to injury, and check bleeding. Phle-bitis, arthritis, epidimitis, and cerebral palsy are but a few instances of the need for cooling hypothermia applications. Such cooling applications are particularly difiicult and burdensome to provide, and are expensive, since they are presently produced by elaborate refrigeration apparatus, or by ice packs which require the presence of refrigeration, freezers or ice makers. Because of the cumbersome size, complex structure, and expense of such refrigeration apparatus, this apparatus is often unavailable even in hospitals or organizations requiring hypothermia cooling equipment, and even where available, the apparatus is difiicult to move from room to room and practically impossible to be transported for out of hospital use. Its use is consequently limited to hospitals or other well endowed and well stalfed organizations. The use of ice packs has also been found disadvantageous because the degree of cooling in application is uncontrollable, and as the ice melts it becomes completely useless and requires attention and supervision.
It is an object of the present invention to provide a thermoelectric hypothermia device utilizing electrically energized thermocouple units for producing a cooling effect at a body contact plate shaped for application to a selected body part, which device can be easily placed on the body to be operated for long periods of time without constant attendance.
Another object of the invention is the provision of a thermoelectric hypothermia device of the type described having removable and interchangeable heat sinks for maximum efiiciency of the thermocouples and for sterilization purposes, as well as interchangeable body contact plates which may be differently shaped for application to various body parts so that the device is adjustable to conform to the various areas of the body.
Another object of the invention is to provide a thermoelectric hypothermia device of the type described which 'is of such light weight, compactness, and regulatable electronic construction, as to make portable hypothermia feasible and practicable.
A further object of the invention is to provide in a thermoelectric hypothermia device of the type described, a removable, replaceable heat dissipater or sink in the nature of a hollow reservoir filled with water or other 'ice suitable liquid, which liquid serves as a suflicient heat sink for the hot side of the thermoelectric units.
A further object of the invention is the provision of a thermoelectric hypothermia device of the character described which is of such small and compact construction that it can be operated wherever needed, not only in a hospital but by visiting nurses and physical therapists in the homes of patients, as well as in areas where injuries occur and immediate cooling is needed. The devices may serve as standard equipment in athletic, recreational, or industrial locations where injuries often occur, as well as in ambulances, fire and police emergency vehicles, armed service first aid ambulatory and field treatment centers, general emergency treatment rooms and the like.
In accordance with the invention, there is provided a portable thermoelectric hypothermia device including a thermocouple assembly adapted to be connected to a source of electric current so that a cooling effect is produced at the cold junctions at one surface thereof, and a heating effect is produced at the hot junctions at the opposite surface thereof. Interchangeable and replaceable body contact plates are provided for selective attachment to the device in heat exchange relationship with the cold junctions of the thermocouple assembly, these plates being variously shaped for application to different parts of the body, and acting as heat transfer surfaces are capable of being temperature regulated. Means are also provided for the removable mounting of a heat sink or dissipater in heat exchange relationship with the hot junctions of the thermocouple unit, the heat sink being thus removable for interchangeability with other heat sinks suitably sized or shaped so as to provide constant maximum thermo performance of the thermopanying drawing, in which:
FIG. 1 is an end perspective view of a portable hypothermia device made in accordance with the present invention;
FIG. 2 is an enlarged sectional view taken along line 2-2 of FIG. 1;
FIG. 3 is a horizontal sectional view taken along line 33 of FIG. 2;
FIG. 4 is a horizontal sectional view taken along line 4-4 of FIG. 2;
FIGS. 5, 6 and 7 respectively, are vertical sectional views of replaceable body contact plates for the device;
FIG. 8 is a side elevational view of a replaceable heat sink or dissipater member for the device, with portions broken away to reveal internal construction; and
FIG. 9 is a schematic view of the thermocouple assembly and the electrical energizing circuit therefor.
Referring in detail to the drawings, and particularly FIGS. 1 and 2, a preferred embodiment of thermoelectric hypothermia device made in accordance with the invention is indicated by reference numeral 10 and generally comprises a thermocouple assembly 12 permanently secured to upper and lower mounting members 14 and 16, a hollow upper reservoir member 18 removably attached to the mounting member 14, and serving as the heat sink or dissipater for the device, and a body contact plate removably attached to the thermocouple mounting member 16.
The hollow reservoir member 18 is made of a heat conductive material such as aluminium or copper, and is preferably of the semi-cylindrical shape shown, its peripheral upper wall 22 being provided with spaced radial ribs or vanes 24 for the dissipation of internal heat. The reservoir member 18 is closed off at each end by end walls 26, and at its bottom by a flat wall 28. The end walls 26 together with peripheral upper wall 22 and the bottom wall 28 completely enclose the hollow interior of the reservoir member 18, providing a liquid tight reservoir for a supply of water or other liquid indicated by reference numeral 38 in FIG. 2.
At its top, the peripheral upper wall 22 has a fluid inlet opening 32 bordered by a threaded neck 34. The inlet opening 32 is closed ofi by an internally threaded closure valve cap 36 which, is removably mounted on the threaded neck 34.
The bottom wall 28 of the reservoir member 18 is flat so as to permit the thermocouple assembly 12 to be mounted flush thereagainst in heat exchange relationship therewith. The bottom wall 28 is provided with suitably spaced circular apertures 38 which register with corresponding apertures 40 in the upper thermocouple assembly mounting member 14 so as to permit the removable mounting of the reservoir member on said mounting member 14 as by screw means 42. In addition, on opposite sides of the bottom wall 28 are pairs of elongated slots 44 which permit hinging together of a plurality of thermoelectric devices 10. The bottom wall 28 also has at one end an elongated slot 46 which provides an outlet through the bottom wall for the leads 48 and 50 connected to the thermocouple assembly 12.
The thermocouple assembly 12 is of a type which is well known and is commercially available, being composed of a series of semi-conductor elements. These consist of a group of semi-conductor elements 52 of the P- type, alternating with a group of semi-conductor elements 54 of the N-type. The P-type semi-conductor elements 52 (litter from the N-type elements 54 in physical properties of the semi-conductor employed.
Each individual pair of semi-conductor elements 52 and 54 are connected at their upper ends by thin plates 56 of electrically conductive metal such as copper, while adjacent pairs of elements 52 and 54 are connected at their lower ends by similar copper plates 58. The plates 56 and 58 are thus arranged to connect the elements 52 and 54 in a series, as best shown in FIG. 9. When electrical cur- -rent is passed through the thermocouple series in one direction, the lower plates 58 will serve as cold junctions and the upper plates 56 as hot junctions. If the direction of electrical current is then reversed, the lower plates 58 become hot junctions and the upper plates 56 will become .cold junctions.
The thermocouple parts are embedded in a filler 60 of polyurethane or other synthetic which acts as insulating means to prevent the heat generated at the hot junctions from overtaking the cold prevailing at the cold junctions. The outer surfaces of the junction plates 56 and 58 are, however, exposed at the respective top and bottom surfaces of the filler 69 as shown in FIGS. 2 and 4, in order to be in intimate contact with the upper and lower thermocouple heat conductive mounting members 14 and 16 respectively. The thermocouple assembly 12 is mounted flat against the surfaces of the thermocouple mounting members 14 and 16 as by soldering or by other suitable means.
The body contact member 26 is made of heat conductive metal, and has a fiat upper wall conforming in size and shape to the lower mounting member 16 of the thermocouple assembly 12. The lower surface of the member 20 is made in a concave shape as shown in order to conform to a correspondingly-shaped portion of the body of the patient to be treated. As shown in FIG. 2, the body contact member Ztlis provided with apertures 62 which register with apertures 64 in the lower mounting member 16 for the reception of screws 66 therein so that the body contact member 20 is firmly mounted with its fiat upper surface flushed against the thermocouple assembly mounting member 16 and in heat exchange relationship therewith. Because of the screw mounting, the contact member 29 may be conveniently removed for sterilization or repair, or for replacement by a similar member or by other contact members of diiferent construction such as the body contact members 68, 70 and 72 shown in FIGS. 57 respectively. The contact members 68, 70 and 72 are each provided with apertures 62 in the same manner as the body contact member 20 for removable screw mounting upon the lower mounting member 16 of the thermocouple assembly 12.
The body contact plates or members 20, 68, 70 and '72 may be made in a variety of sizes and shapes for direct application to selected skin and body areas. For purposes of illustration, the body contact plate 20, as previously indicated, has a concave metal body contact surface 74 for area cooling application on the concave of arm, leg, back, neck, head, etc. The body contact member 68 has a convex lower surface 76 for application to such recessed areas as eyes, armpits, lower back, crotch, etc. The body contact plate or member 70' has a flat heat conductive metallic surface with a plastic or similarly leak-proof liquid container 78 which is pliable for application where such soft and pliable thermally-effected contact is warranted. Body contact plate or member 72, on the other hand, has a porous liquid absorbing sponge 80 or similar absorbent member attached to the to the flat metallic plate portion for use where thermally-eliected moist or wet compresses or packs are desired. Each of the body contact members 20, 68, 70 and 72 is mounted with its flat surface flush against the thermocouple mounting member 16 and held in place by the screws 66 received in the internally threaded sockets or apertures 64.
The upper hollow reservoir member 18 is removably attached in a similar manner as described above for the contact members, and may be disconnected from the thermocouple assembly 12 for sterilization or replacement by reservoir members of different sizes or by a solid metallic heat sink such as the heat sink 82 shown in FIG. 8. This heat sink 82 is integrally made of heat conductive metal, and comprises a plate 84 of the same size and shape as the upper mounting member 14, and a plurality of upstanding fins 86. The plate 84 has a bottom fiat surface 88 which is mounted flush against the thermocouple upper mounting member 14 by the passage of the screws 42 through the apertures 38 formed in plate 84.
As best shown in FIG. 9, the thermocouple leads 48 and Stl are connected to respective terminal strips 90 and 92 at the ends of the thermocouple series. When direct current is fed to the thermocouple assembly 12 through the leads 48 and 50 in one direction, the upper thermocouple plates 56 will be heated, such heat being dissipated by the heat sink 18 or 32. At the same time, the lower thermocouple plates 58 will be cooled, such cold being transferred to the thermocouple mounting member 16 and to the bodv contact plate attached thereto.
FIG. 9, shows schematically a power source unit 94 which may be employed for supplying electric current to the leads 48 and 50. The unit 94 may be adapted to be connected to a line source of DC. current, or may be self contained, including, for example, a nickel-cadmium rechargeable battery or other dry cell battery pack, as a power source. In either event, the power source terminals 96 and 98 are connected by leads 100 through a switch 102, a variable resistor 104, and a polarity reversing switch 106 to the leads 48 and 50, for connection to the thermocouple assembly 12. The switch 102 is of the usual single-pole, single-throw type and may be manually operated to open and close the circuit as desired, or may be associated with a timer (not shown) to automatically open the circuit after a designated heating or cooling period. The polarity reversing switch 106 may be employed to change the polarity of the current supplied to the terminals 90 and 92, so that either heating or cooling will be produced at the body conduct We. The variable resistor 104 may be employed to regulate the power supplied and therefore the degree of heating or cooling produced.
In one commercial embodiment of the device, twenty thermocouple units, each consisting of a pair of barium telluride rods of five millimeter diameter and A1. inch length were assembled in series and operated at 1.25 volts at six amperes. To supply the electrical power, two nickel cadmium cells of 1.25 volts were wired in parallel at six amperes operating conditions and the thermocouple wired to produce a cooling effect. The thermocouple module produced a steady temperature of 335 C. at the heat sink, in an ambient temperature of 24 C. The cold side, with the heat transfer surface in good contact with the skin surface of a patients arm, had a temperature varying between C. and C. This temperature could be varied, of course, by adjustment of the variable resistor 104.
It is to be understood that the instrument is particularly intended to be used to produce cooling at the outer surface of the body contact plates 20, 68, 70 or 72, but use of the polarity reversing switch 106 can instantly convert the same surfaces to provide controlled heat. When the device is used for cooling applications, for example, the relatively large amount of liquid contained in the upper reservoir member 18 renders the latter an extremely efiicient heat-sink. The heat generated at the upper thermocouple plates 56 passes through the bottom wall 28 of the reservoir member 18, is absorbed by the contained liquid 30, and is dissipated to the atmosphere through the spaced radial ribs 24. Because of the high etficiency of the heat-sink, extreme cooling is produced at the lower thermocouple plates 58, which cooling is transferred through the lower thermocouple mounting member 16 and distributed over the attached body contact plates 20, 68, 70 or 72.
In furtherance of the usefulness of the invention, more than one of the thermoelectric hypothermia devices 10 may be hinged or flexibly connected together, as previously indicated, for greater body area coverage, each successive device being connected electrically by conventional methods to the first device so that the total unit is operated uniformly from one set of controls and wires. In such an assembly, each unit also has its own body contact plate shaped for the particular application, and its own replaceable sink.
While preferred embodiments of the invention have been shown and described herein, it is obvious that numerous additions, changes and omissions may be made in such embodiment without departing from the spirit and scope of the invention.
What I claim is: 1. A medical instrument including a thermocouple assembly having hot and cold junctions, respective end walls abutting said hot and cold junctions in heat exchanging relationship therewith, a plurality of heat dissipating members, first connecting means for releasably connecting a selected one of said plurality of heat dissipating members with one of said end walls and for positioning said selected heat dissipating member in heat exchanging relationship with said one end wall, a plurality of applicators, second connecting means for releasably connecting a selected applicator with the other of said end walls in heat exchanging relationship therewith, whereby said plurality of applicators and said plurality of heat dissipating members may be interchanged to provide a medical instrument having a desired heat dissipating member and a desired applicator, and electrical circuit means for connecting said thermocouple assembly to a source of potential.
2. A medical instrument according'to claim 1, in which said selected heat dissipating member is connected with the end wall abutting said hot junction, and said selected applicator is connected with the end wall abutting said cold junction.
3. A medical instrument in accordance with claim 2, in which said selected heat dissipating member comprises a reservoir having a bottom wall abutting said one end wall, and a fluid filling said reservoir.
4. A medical instrument in accordance with claim 2, in which said selected heat dissipating member comprises a bottom wall abutting said one end wall, and a plurality of fins upstanding from said bottom wall to provide means for dissipating the heat produced at said hot junction.
5. A medical instrument in accordance with claim 2, in which said plurality of applicators are provided with differently contoured outer surfaces shaped for placement in heat exchanging relationship with different areas of the body.
6. A medical instrument in accordance with claim 5, in which at least one of said plurality of applicators includes a deformable, pliable reservoir, and a liquid filling said deformable reservoir to provide a relatively soft applicator.
7. A medical instrument in accordance with claim 5, in which at least one of said plurality of applicators comprises a porous member adapted to absorb a fluid to provide a moist applicator.
References Cited UNITED STATES PATENTS 2,584,302 2/1952 Stein 128-399 X 2,798,494 7/1957 Sukacev 128379 3,093,135 6/1963 Hirschhorn 121-303.1 3,133,539 5/1964 Eidus 128399 3,207,159 9/1965 Tateisi 128--303.1
RICHARD A. GAUDET, Primary Examiner. SIMON BRODER, Examiner.