This invention is a light duty consumable prosthesis for use in cadavers to take the place of bones that have been removed from cadavers for medical and/or scientific purposes. Various organizations, such as tissue banks, hospitals, and organ donor associations may surgically remove larger bones from cadavers for scientific and medical reasons such as for donor-to-recipient transplants and tissue research. A replacement for the removed bone component is desirable to preserve visual and structural integrity of the cadaver. The device presented is a light duty prosthesis simulating a bone section. The prosthesis may be placed and positioned in a cadaver to provide tissue support and structure to a limb from which the natural bone has been removed.
An extendable apparatus used as a prosthesis to replace a bone segment in a cadaver is provided. Extension and telescoping capability allow the prosthesis to be extended to a required length to fit into a recipient cavity. The apparatus includes a locking device to prevent telescoping after the locking mechanism has been activated. The light duty consumable prosthesis is designed to be reduced to a minimal amount of insignificant residue when incinerated in a crematory facility.
One problem with a prosthesis used in cadavers is that the prosthesis may be made of a plastic material, such as polyvinyl chloride, that is not consumed in a cremation situation. Cremation of a cadaver is sometimes the chosen method of dealing with a donor body after it has been processed. Plastic prosthesis elements will melt, however the plastic material will not be totally consumed in the cremation process. The prosthesis presented here is made of consumable stock that is acceptable to receiving crematoriums.
It is known to provide a prosthesis to replace bones in a donor cadaver. One embodiment comprises a wooden rod that is cut to an appropriate length to replace the bone that has been removed. This crude prosthesis has technologically evolved into length adjustable units of wood or plastic. One wooden device is made of two compatible sliding pieces, each of the two wooden components having one or more holes drilled therein to ultimately line up with a hole in the mating component. The two wooden components slide relative to each other to attain a desired length and are then pinned together, by a “pin-in-hole” register system, by inserting a pin through aligned ones of the aforesaid holes.
A second type of prosthesis uses plastic pipe to form the structural elements. Two tubes or pipes are used with one tube fitting inside a second tube. One tube has an inside diameter slightly larger then the outside diameter of the other tube thus fitting inside the larger diameter tube. The tubes are provided with one or more holes that will allow pin passage for an indexing pin to pass through and lock the two tube components together at the selected length for the prosthesis.
Various embodiments of the present invention are described below with reference to the drawings figures, wherein like designations denote like elements.
While the invention is described herein in terms of preferred embodiments, the inventor contemplates that alterations and permutations of the preferred embodiments will become apparent to those skilled in the art upon a reading of the specification and a study of the drawing figures. Below is a description of variations of prosthesis embodiments contemplated by the inventor and falling within the scope of the claims unless excluded by specific claim language.
The invention will be understood by a perusal of the drawing figures as described in the following description and enablement of the invention. Starting with
A tubular element 12, in a preferred embodiment, a cardboard tube which may have a fluid resistant external surface, and a generally hollow interior is provided. The tube 12 is approximately 2 inches in external diameter and has a nominal inside diameter of approximately 1.5 inches. The size of the tube is not critical to the invention and the aforesaid dimensions are presented as examples only. A dowel 14, has an outside diameter closely matched to the inside diameter of the tube 12. The dowel 14 may be a wooden dowel in a preferred embodiment but may be made of other consumable materials such as cardboard or a cardboard tube or the like. Thus, in one example, the outside diameter of the wooden dowel 14 is nominally 1.5 inches. The wooden dowel 14 will be a slidable fit inside the tube 12. The outboard end 16 of the wooden dowel 14 may be provided with a enlarged end element 18. This enlarged end element 18 may have an outside diameter similar to the diameter of the tube 12 and an inside diameter of the tube 12 as well. In one embodiment the enlarged element 18 is a section of tubing cut from the same tubing stock used for the tube 12. As the prosthesis, generally 10, is a leg prosthesis, the enlarged element is provided to simulate an ankle joint.
In
A feature of the cylindrical block 26 is the provision of a protrusion or preferably several protrusions such as, but not limited to, the external longitudinal ribs 32 formed on the exterior surface of the cylindrical block 26. These longitudinal ribs 32 provide friction elements between the cylindrical block 26 and the interior of the tube 12 so that when the wooden dowel 14 is inserted into the tube 12, positioned laterally to a desired length and then rotated, the cam locking elements 24 will cause friction interference between the tube 12 and the wooden dowel 14 such that the relative longitudinal positions of the tube and the wooden dowel 14 will be fixed due to the pressure of the surface of the wooden dowel 14 and the interior surface of the tube 12.
Before looking at
The leg bone prosthesis, once positioned, in the cadaver can remain with the cadaver through the cadaver's transportation and final disposition whether the cadaver be buried or cremated. The leg prosthesis is consumable to a large extent in the cremation process. The cardboard tube 12 and the wooden dowel 14 are fully consumable. The ankle joint is fully consumable and the second foam element 22, the simulated knee joint, and the hip emulating element 20, the foam element 20, are virtually totally consumed as they are low density products that will be reduced to insignificant ash. The cylindrical block 26, a plastic material in one embodiment, but alternatively a block made of more consumable material, presents an insignificant quantity of material upon cremation, that has been shown to be unobjectionable to operation of a crematorium. In a known light duty prosthesis made of plastic tubing, the residue from the cremated plastic tubes yields a significant quantity of melted plastic presenting a collection and disposal problem for the crematorium. This is a serious concern for the crematorium operator as the melted plastic will “gum up” the floor of the cremation chamber. Removing and cleaning up the material, which may adhere to the floor, can result in flooring being removed with the plastic residue. In any event the extra work necessary to clean up the gummy residue, and possibly replacing flooring, is an expense in time and manpower that is avoided by use of the prosthesis of this invention. Some crematorium operators will avoid the melted plastic problem by removing plastic (PVC pipe and the like) prosthesis limbs before cremation of the cadaver. This of course, is an added processing step in handling the cadaver that is avoided by using the invention disclosed herein.
Returning to
A projection 70, such as a nail or staple, may be positioned to project from the dowel 40 within an inch or so of the end of the dowel 40. This projection prevents the tube 36 from sliding too far inboard along the dowel which could allow the cam 24 from being pushed out the end of the tube 36.
A bore is formed in the end of the dowel 40 at the end of the dowel that doesn't have the cam device attached thereto. The bore will accommodate a flexible, bendable connector 56 as described below.
The second part of the arm prosthesis, item 42, representing the upper arm of the recipient cadaver, is comprised of several parts including a tube 44 also made of consumable material, such as, but not limited to, cardboard coated in a moisture resistant coating such as a single ply of plastic wrap formed integrally with the manufacture of the cardboard tube. At one end of the second part 42 of the arm prosthesis generally 34, is a enlarged portion 46 representing or simulating a shoulder. A wooden dowel 48 of the upper arm 42 has an enlarged portion 50 of consumable material. This enlarged portion 50 represents an elbow of the prosthesis generally 34. The wooden dowel 48 is a slidable fit in the tube 44. The end of the wooden dowel 48 is provided with a hole (not shown) drilled therein. This hole in the wooden dowel 48 accommodates a flexible, bendable connector 56. The other end of the connector 56 is positioned in the hole in the end of the dowel 40. The connector 56 may be a short piece, on the order of three inches in length, of electrical wire having a diameter of about five/sixteenths inch. The connector is designed to be bent into a desired position to, for instance, allow the arm of the cadaver into which the arm prosthesis is inserted to be folded to an at rest position without interference between the upper arm 42 portion and the lower arm portion 36.
An eccentric locking device is also used in the upper arm portion of the arm prosthesis in the location generally 24.
In
As can be envisioned, the arm bone prosthesis, once positioned in the cadaver can remain with the cadaver through the cadaver's transportation and final disposition whether it be buried or cremated as discussed above with respect to the leg prosthesis. The arm bone prosthesis is also consumable to a large extent in the cremation process. The cardboard tubes and the wooden dowels are fully consumable. The arm prosthesis is fully consumable except for the eccentric cam blocks and the bendable portion 56, the totality of these several elements is such an insignificant mass of plastic and wire that it poses no problem as far as residue from a cremation operation is concerned. Even in an arm prosthesis of plastic material, as is known in prosthesis of this type, the residue from the cremated plastic tubes yields a significant quantity of melted plastic presenting a collection and disposal problem for the crematorium as addressed above.
In summary the leg prosthesis comprises a consumable light duty prosthesis having a tubular element with an inside diameter; a wooden dowel element having an inboard end and having a diameter allowing insertion of the wooden dowel element into the tubular element; and a cam locking device having an eccentric cam element affixed to the inboard end of the wooden dowel element. The cam locking device comprises a cylindrical block having a through bore. The through bore and a pilot hole formed in the end of the wooden dowel are eccentrically offset relative to each other. The cam locking device also includes an axle, which can be a threaded fastener, carried in the through bore of the cylindrical block and extending into the pilot hole of the wooden dowel. The cylindrical block is free to rotate eccentrically on the axle. It is advantageous to have a projection, in one embodiment a longitudinal rib or, in a preferred embodiment, multiple longitudinal ribs, projecting from the surface of the cylindrical block. These ribs will increase the friction between the cam lock block surface and the interior of the cardboard tube, or the like, to decrease the tendency of the cam block to slip inside the tube when the tube and the dowel are rotated relative to each other.
The tube and the wooden dowel are an interference fit when the wooden dowel is positioned in the tube and the wooden dowel is rotated relative to the tube. This restraint system is a significant improvement over the devices known to the inventor as there is no need for the pin-in-hole arrangement used in other devices.
The leg prosthesis includes a hip emulating element that may be fixedly attached to one end of the tube, the end opposite the end of the tube that will accept the wooden dowel and cam locking device, of the tube. The hip emulating element, in one embodiment, is a low density expanded foam element.
A second foam element, again in one embodiment, a low density expanded foam element, simulating a knee joint, is slidably carried on the tube. It will be slidable along the tube to approximate a knee position.
Toward the end of the wooden dowel, at the end not normally inserted into the inside diameter of the tube, an enlarged end element simulating an ankle joint is positioned at the end of the wooden dowel. This ankle joint element may be a section of tubing similar in internal and external dimension to the tube. In a manufacturing situation the tubing used for the tube is simply cut into short pieces and affixed to the end of the wooden dowel to form the simulated ankle joint. Obviously this ankle joint, as well as the simulated hip and knee joints, are not articulatable as articulation is not needed.
It is desirable that the tubes of the various prosthesis products disclosed herein, in one embodiment these being cardboard tubes, are moisture resistant. This can be accomplished by incorporating a sheet of film stock on or over the cardboard tube used for the tubes. Also, the tubes can be sprayed or otherwise coated with a moisture resistant coating.
The single part upper arm prosthesis, shown in
In addition to the apparatus described above, the inventor contemplates that the method of using the consumable light duty prosthesis as described to replace a removed natural bone can be implemented with the apparatus. Such apparatus for use in performing the method will include a tubular element having a inside diameter; a wooden dowel element having an inboard end and having an outside diameter allowing insertion of the wooden dowel element into the tubular element; and a cam locking device having an eccentric cam element affixed to the inboard end of the wooden dowel element.
This disclosure sets forth an embodiment that satisfies and meets the objects and advantages of the invention set out above. Accordingly, neither the above description of preferred exemplary embodiments, nor the abstract defines or constrains the invention. Rather, the issued claims variously define the invention. Each variation of the invention is limited only by the recited limitations of its respective claim, and equivalents thereof, without limitation by other terms not present in the claim.
In addition, aspects of the invention are particularly pointed out in the claims using terminology that the inventor regards as having its broadest reasonable interpretation; the more specific interpretations of 35 U.S.C. § 112(6) are only intended in those instances where the terms “means” or “steps” are actually recited. The words “comprising,” “including,” and “having” are intended as open-ended terminology, with the same meaning as if the phrase “at least” were appended after each instance thereof.