US2366989A - Therapeutic device - Google Patents

Description

Jan. 9,` 1945 B. R. ROBERTSON v THERAPEUTIG DEVICE Filed Nov. 26. 1938 Patentecl Jan. 9, 1945 UNITED STATES f PATENT OFFICE THERAPEUTIC DEVICE BassettR. Robertson, San Diego, Calif., assignor `to. Freez-A-Bag, Inc., Los Angeles, Calif., a

corporation of California l l l Application November 26, 1938, Serial No. 242,503

`(Cl. 62-1) n 1 Claim.

This invention relates to improvements in therapeutic devices, specically flexible containers filled with or containing a solution which is normally liquid but which is capable of beingv frozen or having its temperature reduced to below the freezing point of water and still maintain a flexible or moldable condition. The invention further relates to a therapeutic device in the form of a pliable or flexible containerAfilled-with a loose or mobile granular substance having a temperature below the freezing point of water;

and preferably below 28 F., the containerand its contents beingilexible and pliable so as to permit the container to be molded by hand to cause it to conform to bodily'contours.

' are flexible even though they are subjected to but The invention furthermore pertains to a form of apparatus and a method' of facilitating the use of such therapeutic devices.

Cold packs are a necessity in the treatment of many cases of infection, post operative conditions, etc. Cold packs are, for example, used very extensively to prevent bacterial development in certain cases of infection and to prevent hemorrhages as a result of tonsillotomy and the like. Heretofore, rubber bags containing chipped `ice 4have been employed but obviously the heat-absorbing capacity of the usual cold bag is limited.

a temperature of 22 F., for example. By reason enclose a suitable quantity of the aqueous glyc,

of the bulky character of usual ice bags, patients are subjected 'to considerable discomfort since many regions to which an ice pack need be applied are incapable of sustaining anyappreciable weight. A still further disadvantage to the use of ice lies in the fact that ice crystals and the edges of broken ice are sharp'e and angular and exhibit sorbing capacity weighs only a fraction as much 'as an ice bag of the same heat-absorbing capacfity. Moreover, therapeutic devices of this inventionare flexible, pliable and adapted to conform to the body so as to obtainrbetter contact. In addition, the cold bags of this invention need not smooth external surface.

slight pressure of the hand, thereby permitting.

the container and its contents to be applied to any'curved surface or portion of the body and obtain practically perfect Contact between the container and the surface.

The container in its preferred form is a relatively thin container provided with a substantially Means have been de'- vised whereby these containers may be sealed to erine solution. and means have also been provided whereby the containers may be rapidly and ecientlychilled or frzen, the freezing cabinet permitting 'rapid absorption of heat from the containers so that a relatively small number of such containers may supply the needs of a great many patients.

It is an object of the invention, therefore, to provide a therapeutic device in the form of a Aheat-absorbing pad, bag, or. othercontainer, the container a'nd. its contents being flexible, bendable and moldable even though its contents are at temperatures below the freezing point of water.

A further object of the invention is to provide V a substantially smooth-surfaced, flexible, sealed container, the contents being capableof assuming a granular or sand-like condition at temperatures below the freezing point of water.

Astill further object of the invention is to V provide means and methods of preparing and utilizing therapeutic devices capable of absorb-` ing large amounts of heat in an effective manner.

These and other objects, advantages, uses and modiiications of the invention willbecome apparent to those skilled in the art from the fol Y lowing'detailed description of preferred forms. In order to facilitateunderstanding, reference vention, a\porton will be had to the appended drawing, in which:

Fig. 1 is a perspective view of a simple therapeutic device made in accordance with this inof this device being broken away.

' Fig. 2 shows another form of device in use and F5 illustrates its ilexibillty.

.uses contemplated, 'particularly Fig. 3 is a side elevation, partly in section, of a refrigerating cabinet in which the therapeutic devices of this invention may be conditioned.

As shown in Fig. 1, the container may comprise a hollow, substantially seamless pad I made of rubber, rubber composition, or other flexible, relatively limp, preferably semi-elastic material. In one form of the device a tubular extension may be formed, such tubular extension being integral with the walls of the device, such tubular extension being used for filling the container l0 with a suitable solution or liquid medium which is liquid at atmospheric temperatures but which is capable of solidifying or being frozen to temperatures below the freezing point of water without the formation of a rigid or strong solid mass. After the container has been filled with such a liquid, the tubular extension may be forced into the container to assume the position indicated at il and the opening then sealed with a plug or cemented. As a result, the container l0 is substantially smooth and is free from those removable closures which characterize the ordinary ice bag.

The liquid or solution used in lling the container should have the property of being chilled to temperatures appreciably below the melting point of ice without the formation of hard, strong, inflexible bodies. Solutions of glycerine and water have been found to be eminently suited for this purpose. Ordinarily, such solutions may contain from about 12% to 25% of glycerine by volume, the remainder consisting of water or water with but a minor proportion of some other substance.

When a solution is employed, said solution being made by miXing l volume of glycerine with volumes of water, it will lbe found that the solution will solidify or freeze at about 23.5 F. and such solution containingapproximately 17% of glycerine, appears' to be admirably suited for the in hospitals, sanitaria, etc.

Containers filled with solutions of the character stated may be chilled or frozen in a number of different ways. The typical 5 to 1 solution mentioned is readily converted into the desired state by placing the containers or bags lled with the solution upon trays or shelves of a refrigerator provided with coils capable of expanding a refrigerant, the temperature in such refrigerator or onthe surface of the shelves being preferably below about 20 ZE'.- In order to facilitate the4 freezing operation, it is desirable that the therapeutic devices of this invention be placed in virtual contact with the expansion coils,

A form of device which has been found to be eminently suited for' the preparation and conditioning of thev therapeutic devices of this invention is'illustrated in Fig. 3. As there shown, the device comprises an exterior housing l5 provided with a freezing compartment', generally indicated at i6, andla suitable door I1.. A conduit' I9 may extend upwardly from the liquid refrigerant storage f8 and` then zig-zag in a substantially horizontalfplane so as to form a shelf 20. 'Additional expansion coils arranged in horizonta'l spaced planes,4 such as the shelves 2|, 2,2, etc.,"are connectedito the end of the shelf 20 by suitable connecting conduits. The line 23 from `the lowermosti shelf is connected to the compressor and other elements of the refrigerat` ing system which, in the exemplary showing of the figure, are located in the bottom of the housing. The various shelves 20, 2l, 22, etc., may

also include thin covering sheets 20', 2l', etc., suitably fastened to the upper surfaces of the coils so as to afford a smooth surface on which the therapeutic devices may be supported. Front edge portions of the sheets 20', 2i', etc., may be turned down or under as indicated at 2i and 28 so as to form edges shielding the ends of the coils. The rear edge portions of each of the thin sheets 20', 2l', etc., may be bent upwardly and fastened to the rear wall of the cabinet as indicated at 28,'- for example.

The spacing between the shelves, such as the shelves 2| and 22, should be sufcient to permit the ready introduction of the therapeutic devices while at the same time permitting the heat-absorbing effect of the coil constituting shelf 2l to exert a refrigerating effect upon any therapeutic device placed upon the lower shelf 22. If, for example, the therapeutic devices are between 0.5 and 0.75 inch in thickness, the space between the top of the lower shelf and the bottom oi the upper shelf may be only about 3 inches. By expanding a gasiiied refrigerant in the coils arranged as shown and by supporting the therapeutic devices upon the metal covering sheets which in turn are welded, soldered or otherwise directly connected to the coils, the contents of the therapeutic devices may be rapidly chilled to below their solidilication point.

If, for example, a 5 to 1 solution is contained in the therapeutic devices I0, the coils and shelves of the conditioning cabinet may be maintainedA at about 15 F. The 5 to 1 solution of the therapeutic devices will solidify as stated at about 23.5 F. In the event a patient requires a cold pack, the attendant or nurse may remove the therapeutic device from the refrigerating cabinet and it will be found that even though such device appears fairly rigid, it can be molded, bent, flexed and distorted by simplepressure of the lingers, the con tents appearing to be granular or crystalline and substantially free from large lumps or pieces with jagged edges. Instead, the grainy material within the bag appears to be small and rounded and as a result the therapeutic device may be applied to the desired portion of the patients anatomy and molded so as to insure thorough contact.

Fig. 2 illustrates a long, narrow bag or container which may be adapted to lay at when in extended form, but after the contents have been f reduced in temperature to the required extent,

such bag canbe molded by finger pressure to fit around the neck of the patient, the ends of the bag being then connected or removably connected. Bags of this type are preferably provided with elastic coverings.

-By varying the proportion of glycerine contained in the solution, within the range heretofore given, the heat-absorbing capacity of the solution and of the therapeutic device in which it is contained may be varied, without destroying the peculiar characteristics attained by freezing said solutions.; If less than about 8% 'or 10% of glycerine is contained in the solution, the peculiar grainy character of the frezen product is not attained. 'The contents of therapeutic devices composed of a solution made by mixing 6 parts of water with 1 of glycerine will be found to have a freezing point of about 24,9o F., while the freezing point of a solution made by mixing l part of glycerine with 4 parts of water will be found to be about 20 F.

In all events, it is desirable that the contents be capable of attaining temperatures below about 29 F. In making these solutions it has been Ifound that technical grades of glycerineare entirely satisfactory. Glycol derivatives and substitution products such as diethylene glycol, etc., can be used instead of or in addition to glycerine with similar results.

After the heat-absorbing capacity of a therapeutic device of this invention has been utilized and the contents have liquefied vand have absorbed sufficient heat so that a desired chilling effect is not being attained, the container is returned to the refrigerating or conditioning cabinet to be again frozen. It is to be noted that in thisv manner the attendants and nurses need not nl] and refill the bags as is the case when ice is employed, thereby greatly facilitating their work and effecting a large saving in time. The usual type of rellable bag has but a'lirnited life due to the action of sharp and hard ice particles on the bag and due to the repeated strains imposed thereon by twisting the normal screw-threaded closure, but the devices of this invention are free from these objections and can be used for extremely'long periods of time.

Moreover, attention is again called to the fact that the therapeutic devices of this invention are l provided with substantially smooth external surfaces and the heat-conducting capacity of the surface of the container is virtually uniform. For this reason the patient is not subjected to the angularities of closure members nor the more intense heat-absorbing elect of a large metal cap or opening as compared with the fabric covering ordinarily found on the usual style of ice bag.

I claim:

A device for cooling a portion of the body of a patient, said device comprising a bag constructed ofrthin exible rubber and having sealed therein a quantity of Water and a suicient quantity of depressant of the freezing point of the Water and having the property of forming therewith, at `15emperatures a few degrees below 32 F., a slushy mass that may be molded by the ngers of an operator, without substantial risk of puncturing the walls of the bag, to conform to the shape of such body DOltiOn of the patient, said depressant being selected from a group consisting of glycerine, glycol and diethylene glycol.

BASSE'I'I' R. ROBERTSON.

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