US3415243A

US3415243A - Means for making a surgical cast

Info

Publication number: US3415243A
Application number: US472783A
Authority: US
Inventors: Zachary D Sheldon
Original assignee: Avco Corp
Current assignee: Avco Corp
Priority date: 1965-07-19
Filing date: 1965-07-19
Publication date: 1968-12-10
Anticipated expiration: 1985-12-10

Description

Dec. 10, 1968 z. D. SHELDON 3,415,243

} MEANS FOR MAKING A SURGICAL CAST Filed July 19, 1965 INVEN TOR ZACHARY D. SHELDON 8) MDW A T TORNEYS United States Patent (3 3,415,243 MEANS FOR MAKING A SURGICAL CAST Zachary I). Sheldon, Andover, Mass, assignorto Avco Corporation, Cincinnati, Ohio, a corporation of Delaware Filed July 19, 1965, Ser. No. 472,783 26 Claims. (Cl. 128-90) ABSTRACT OF THE DISCLOSURE An article of manufacture for use as a surgical cast which includes a plurality of reagents which are reactive when intermixed to form a hardenable cast material. The reagents are embodied in a pliable sheet, preferably surgical gauze. The reagents are maintained in a dormant state by virtue of the fact that one of the reagents is encapsulated within a rupturable material.

This invention relates to surgical casts, and more particularly to an article of manufacture for use as a surgical cast, and its method of application.

Heretofore, surgical casts have generally been manufactured from a plaster of Paris material. The surgeon is required to mix plaster material with water to provide a moldable cast material at the site of application of the cast.

The manufacture of these surgical casts is both a complex and often messy process due to the variables involved in the operation and the requirement of handling the large quantities of wet plaster. Therefore, the need for providing a cast which is less diflicult to apply, and which requires no special talent in its proper application has long been evident.

In the application of the common plaster of Paris cast, the mixture is effected by temperatures of the water, quantity of water, and type of plaster of Paris used. Taking these variables into consideration, it is apparent that the surgeon applying the cast must be skilled in the art, as an improper mix may result in excess heat being developed in the applied cast, or a resultant cast of inferior quality.

In addition, the storage of plaster of Paris material presents a problem in that excessive moisture tends to react with the stored material, and the shelf life is thereby limited unless appropriate precautionary measures are observed. The present invention therefore, has vas a general object to eliminate or minimize many of the objectionable features found in prior art surgical cast, and provide an article of manufacture for use as a surgical cast which has a long shelf life.

A more specific object of the invention is to provide an article of manufacture for use as a surgical cast which provides a fail-proof mixture of the cast reagents in every application.

Another object of the invention is to provide an article of manufacture for use as a surgical cast which is simple to manufacture, easily stored, and is easily applied.

A further object of the invention is to provide an article of manufacture for use as a surgical cast which article facilitates application of a cast to a body member.

Still another object of the invention is to provide a method of forming a substantially rigid member, such as a surgical cast, which method is easy to perform, and repeatable to obtain the required end result.

Still another object of the invention is to provide a method of forming a surgical cast which method may be performed with a minimum of equipment, and with a minimum of experience or skill.

A more specific object of the invention is to provide an article of manufacture for use as a cast wherein at least one of the cast forming reagents is encapsulated in a rupturable material.

A 'further specific object of the invention is to provide a method of forming a cast wherein a hardening agent is positioned adjacent :a member by breaking an encapsulation whereby the hardening material is released.

Yet another object of the invention is to provide an article of manufacture for use as a cast wherein the cast forming reagents have a modifying agent interspersed therein.

One of the more recent technological developments has produced methods whereby liquids, solids, or gases may be encapsulated within miniature spheres. One such method is described in the US. Patent No. 3,155,590 to Miller et al. and assigned to National Cash Register Company.

The present invention advantageously employs this or other like technology to encapsulate one or more of the reagents or components necessary to produce a cast material. The various components of the hardenable material are mixed in the dormant state, which dormancy is maintained by encapsulating one or more of the reactive agents to keep them separated.

The reagents are then placed on a carrier, generally a pliable sheet or gauze material. which may be rolled or folded into a compact article.

The method of utilizing the article to form a cast comprises merely breaking the capsule material, applying the carrier to conform to the injured body member, and allowing the material to become rigid.

The novel features that are considered characteristic of the invention are set forth in the appended claims; the invention itself, however both as to its organization and method of operation, together with additional objects and advantages thereof, will best be understood from the fol lowing description of a specific embodiment when read in conjunction with the accompanying drawings, in which:

FIGURE 1 is an elevational view showing an article manufactured in accordance with the present invention which article is provided in the form of a rolled tape or bandage;

FIGURE 2 is a sectional view taken on the line 22 of FIGURE 1 showing on a greatly enlarged scale the elements of the present invention;

FIGURE 3 is a schematic view showing the article of the present invention being operated on during its :application;

FIGURE 4 is a schematic view showing an alternate embodiment of the operation shown in FIGURE 3; and

FIGURE 5 is an elevational view showing an application of the article shown in FIGURE 1 and taken on a smaller scale.

Referring now to the drawings especially FIGURES 1 and 2 there is shown an article 10 in the form of a rolled bandage or tape for use as a surgical cast material. The article 10 may be of .any suitable width and is compactly rolled for ease of handling. The length of the article 10 is generally limited only by the desired weight of the roll.

As best shown in FIGURE 2, the tape or bandage provided by the article 10 comprises a carrier 11, generally of pliable sheet material. The carrier 11 is preferably comprised of a liquid permeable material (for purposes which will be evident as the description proceeds) and may be folded upon itself as shown in FIGURE 2, or may be of two separate sheets. A typical method of [fabricating the carrier :11 is to employ a plurality of surgical gauze sheets stacked one upon the other to a desired thickness, thus maintaining a closeness of weave which minimizes the passage of solid particles therethrough.

The carrier 11 has disposed thereon a plurality of reagents 12 which are normally dormant, but react when intermixed to form a hardenable cast material. Typical of such reagents 12 are the more commonly used calcined plaster of Paris and water.

Other materials which are useful for this purpose are a semiprepolymer binding reagent and an activating reagent of polyol which may be a polyether derived from sorbitol and propylene oxide. The latter materials, when used, are quite effective to produce a lightweight cast, which is desired in most applications.

Referring still to FIGURE 2, it should be noted that the reagents 12 are sealed within a multiplicity of capsule elements 13 fabricated from a rupturable material. The capsule elements 13 may be from 1 micron in diameter to A3" diameter and should be of a non-toxic material for surgical applications when used in direct contact with the skin. For example, the elements 13 may be manufactured from polyethylene, gelatin, polypropylenes, silicons and Teflon or many other rupturable polymeric materials.

As previously discussed, the utilizing of a plurality of layers of surgical gauze as a carrier 11 is effective to retain the capsules 13 in the article 10. The capsules 13 are held in place by the inner strands of the gauze material and are prevented from passing completely through the carrier 11 by the outer layers of gauze.

However, should it be desirable to use a single layer of cloth, or other material for the carrier 11, the capsules 13 may be cemented in place using any relatively porous cementing material, for example a paste formed of plaster of Paris and water.

Referring now to FIGURE 3, a pair of rollers 14 and 16 are schematically shown disposed in spaced relation such that the tape or bandage article may be fed therebetween, the rollers being so spaced as to cause a rupturing force to be applied to the capsule elements 13 when passed therebetween, thus releasing the reagents 12 from within the elements 13 to intermix with other reagents and form the hardenable cast material.

In FIGURE 4 an alternate embodiment of the capsule breaking apparatus is shown. An infrared lamp 17 directs high-energy heat to the surface of the tape 10. The increase of temperature of the reagents 12 causes an increase in vapor pressure within the capsules 13, and by carefully controlling the temperature, the spheres are broken by internal pressure without damage to the carrier 11.

To conclude the application of the cast to a body member, the tape or bandage 10 is placed adjacent the body member by wrapping as shown in FIGURE 5. By maintaining proper control over the temperature produced by the reaction of the reagents 12, the tape 10 may be wrapped directly in contact with the body member immediately after crushing the reagent holding capsules 13. Control of the reaction temperature is generally maintained by proportioning of the reagents 12, which is well known in the art. However, as will be hereinafter set forth in detail, the present invention provides for adding a modifying media to the cast forming material to absorb the heat of reaction, and thereby obtain the desired result. Should it be desired to provide additional comfort to the patient due to a delicate skin condition or other circumstance a stocking or thin layer of gauze material may be applied to the member just prior to application of the tape 10.

The tape article 10 is generally wound with each successive layer over-lapping the preceding layer, and is passed first in one direction and back in the other to a desired thickness. The number of passes, and the resultant thickness of the cast, may be varied according to the application, considering the materials used and the rigidity necessary to restrain the member.

In addition to the reagents 12, the carrier 11 may be provided with various modifying agents such as porosity inducing media 18, thermal absorbing elements 19, and/ or strengthening fibers 20. All of these agents may be encapsulated to form uniformity of the cast producing material or encapsulation may be restricted to include only those elements which react with one another, or react with air or moisture.

A porosity inducing medium 18 which is effective with plaster of Paris is ordinary cork, however, vermiculate or cotton linters may also be effectively used. In addition, should the porosity inducing elements be encapsulated, as the reagents, a porosity may be induced by simply encapsulating air.

As previously considered, many reagents useful as a cast forming material may produce undesirable heat. To insure comfort to the patient, materials may be provided to absorb heat from the reaction of the reagents 12. The problem is easily handled in the present invention by including on the carrier 11 a thermal absorbent element 19, which also may be encapsulated. It is generally desirable to choose those thermally absorbent elements 19 which do not interfere with X-ray penetration of the cast. Metallic aluminum powder is a common material used for this purpose, however, powders of magnesium, durel or boron nitride are equally effective in producing the desired result.

In the description of FIGURE 5 reference was made to providing a thickness of cast which gives adequate strength to properly restrain the body member.

One other method of increasing the strength of the cast is to include fibers 20 in the hardenable cast material. The fibers 20 may be encapsulated and intermixed with the reagents to produce a reinforcement of the material, or may be introduced in the uncovered form. For this purpose, cotton linters are effective reinforcing agents, however, nylon fibers are also used for reinforcing purposes.

It should be understood from the foregoing that only those agents or reagents which are considered to have qualities requiring encapsulation need be provided in capsule form. In practicing the present invention, one or all of the cast forming material constituents may be encapsulated.

For example, in the preparation of a cast forming material wherein calcined plaster of Paris, water and nylon strengthening fibers are used, only the water need be encapsulated to prevent reaction occuring prior to application of the cast. However, for the purpose of providing a more homogeneous material for mixing, and to prevent the reagents and agents from separating into layers when on the carrier, the water, plaster of Paris and nylon fibers may be provided in capsules of substantially equal s1ze.

As a further example, the reagents 12 may comprise a mixture of elements which are not hardenable until exposed to air such as a common household cement. In this example, the hardenable agent is encapsulated and may be employed solely with the carrier to form a hardened cast.

From the foregoing description it should be concluded that the present invention provides an article of manufacture 10 which when formed into a surgical cast effectively overcomes many of the objectionable features of of prior art casts.

In addition, the various objects of the invention are further achieved by providing a cast material which is easily subjected to stringent quality control and analysis. By pre-mixing the reagents in the dormant state, each batch of cast material may be tested as to thermal qualities during reaction, porosity, absorption, and rigidity in the final form. These, and other qualities of the cast may be closely controlled by employing the present invention.

It should also be evident that employment of a liquid permeable material for the carrier 11 in combination with porosity inducing media as described allows the injured body member to breathe while the. cast is in place.

Also, the providing of a cast material which is applied as a tape or bandage, allows a more perfect adherence to the contour of the body member, which is one highly desirable feature of a surgical cast.

preferred embodiment illustrated, all of which may be achieved without departing from the spirit and scope of the invention as defined by the following claims:

I claim:

1. An article of manufacture for use as a surgical cast which comprises:

a carrier comprised of surgical gauze material,

a plurality of dormant reagents disposed on said carrier, which reagents are reactive when intermixed to form a hardenable cast material, and

a multiplicity of capsule elements of rupturable material, each containing one of said reagents.

2. The article defined in claim 1 wherein one of said plurality of reagents is calcined plaster of Paris and another of said reagents is water.

3. The article defined in claim 1 wherein one of said plurality of reagents is a semi-prepolymer and another of said reagents is a polyol activator.

4. An article of manufacture for use as a surgical cast which comprises:

a carrier of pliable sheet material,

a plurality of domant reagents disposed on said carrier,

which reagents are reactive when intermixed to form a hardenable cast material,

a multiplicity of capsule elements of rupturable material each containing one of said reagents, and

an agent having high thermal absorption qualities interspersed with said capsules.

5. The article described in claim 4 wherein said agent having high thermal absorption qualities is aluminum powder.

6. An article of manufacture for use as a surgical cast which comprises:

a carrier of pliable sheet material,

a plurality of dormant reagents disposed on said carrier, which reagents are reactive when intermixed to form a hardenable cast material,

a porosity inducing agent interspersed with said capsules.

7. The article described in claim 6 wherein said porosity inducing agent is cork.

8. An article of manufacture for use as a surgical cast which comprises:

a carrier of pliable sheet material,

a multiplicity of capsule elements of rupturable material each containing one of said reagents, and reinforcing fibers interspersed with said capsules.

9. The article described in claim 8 wherein said reinforcing fibers are cotton linters.

10. An article of manufacture for use as a surgical cast which comprises:

a liquid permeable carrier comprised of adjacent sheets of surgical gauze,

a plurality of reagents disposed between said sheets of material, which reagents are reactive when intermixed to form a hardenable cast material, and

a multiplicity of capsule elements of rupturable material each containing one of said reagents.

11. An article as described in claim 10 wherein one of said plurality of reagents is calcined plaster of Paris and another of said reagents is water, and said water reagent is contained by said multiplicity of capsule elements.

12. An article as described in claim 10 wherein one of said plurality of reagents is a semi-prepolymer and another of said reagents is a polyol activator, said activator reagent being contained by said multiplicity of capsule elements.

13. A method of forming a surgical cast which comprises:

providing a plurality of reagents embodied within a carrier fabric which are reactive when intermixed to form a hardenable cast material, maintaining said reagents dormant by providing at least one of said reagents in the form of a multiplicity of particles encapsulated by a rupturable material,

breaking said rupturable encapsulating material to release said one reagent into intermiring relation with the other of said reagents, and

applying the cast material to a body member.

14. A method of forming a surgical cast which comprises:

providing a plurality of reagents embodied within a carrier fabric which are reactive when intermixed to form a hardenable cast material,

maintaining said reagents dormant by providing at least one of said reagents in the form of a multiplicity of particles encapsulated by a rupturable material, applying the cast material to a body member, and breaking said rupturable encapsulating material to release said one reagent into intermixing relation with the other of said reagents.

15. A method of forming a surgical cast which comprises:

providing a carrier of pliable sheet material having a plurality of reagents dispersed therein, which reagents are reactive when intermixed to form a hardenable cast material,

maintaining said reagents dormant by providing at least one of said reagents in the form of a multiplicity of particles encapsulated by a rupturable material,

breaking said rupturable encapsulating material to release said one reagent into intermixing relation with the other of said reagents, and applying the cast material to a body member. 16. The method described in claim 15 which further includes the step of providing spaced rollers, and wherein the breaking of said rupturable encapsulating material is accomplished by passing said carrier between said spaced rollers.

17. The method described in claim 15 which further includes the step of providing a source of high heat energy and wherein the breaking of said rupturable encapsulating material is accomplished by applying said heat energy to said capsules causing said capsules to burst from internal pressure.

18. A method of forming a surgical cast which comprises:

providing a carrier comprising a pair of pliable sheets and a plurality of reagents which are reactive to form a hardenable material disposed between said sheets, one of said reagents being in the form of a liquid, 7

maintaining said reagents dormant by providing said liquid reagent in the form of a multiplicity of capsule elements containing said liquid,

breaking said capsule elements to release said liquid reagent into inter-mixing relation with the other of said reagents, and

applying said carrier to a body member.

19. A method of forming a substantially rigid member which comprises:

providing a carrier of surgical gauze material having a plurality of reagents disposed thereon which re agents are reactive when intermixed to form a hardenable material,

maintaining said reagents dormant by providing at least one of said reagents in the forming a multiplicity of particles encapsulated by rupturable material, and

breaking said rupturable encapsulating material to release said one reagent into intermixing relation with the other of said reagents.

20. An article of manufacture for use as a surgical cast which comprises:

a carrier comprised of pliable sheet material,

a plurality of diminutive particles of difierent reagents disposed on said carrier, which reagents are reactive when intermixed and brought into contact to form a hardenable cast material,

means for maintaining said particles of different reagents physically separated by maintaining said reagents in a dormant state, and

an agent interspersed throughout said reagents for modifying said cast material.

21. The article of manufacture described in claim 20, wherein said modifying agent is a porosity inducing media.

22. The article of manufacture described in claim 21 wherein said porosity inducing media is cork.

References Cited UNITED STATES PATENTS 2,714,974 8/1955 Sawyer. 3,027,336 3/1962 Gotz et a1. l2890 XR 3,048,169 8/1962 Pierce 128-90 3,208,102 9/1965 Rubio. 3,215,137 11/1965 Laakso 128 3,266,625 8/1966 Hardman.

RICHARD A. GAUDET, Primary Examiner.

R. L. FRINKS, Assistant Examiner.

US. Cl. X.R.