Patent Application
20100076357
The invention relates to a sleeve for application to a human extremity, more particularly, to a residual limb coupled to a prosthetic device.
Conventional prosthetic liners are worn between and/or over a human extremity and a prosthesis component such as a rod, pylon or socket. Such liners form an intermediate layer between the prosthesis and the extremity, and usually have a tubular construction with a closed, distal end. The liners adhere to the extremity on one side and to the inner side of the prosthesis component on the other side. Prosthetic liners may also have a cushioning effect and can act as a seal over the extremity and/or prosthetic component.
The invention is in one embodiment a sleeve for application to a human extremity. The sleeve has a tubular structure with distal and proximal openings, a pre-flexed section between the openings and distal and proximal contact zones on opposing sides of the pre-flexed section. At least the distal contact zone extends from the pre-flexed section in a conically tapering manner. A distal end zone is disposed between the distal contact zone and the distal end. The distal end zone may also be conically tapered toward the distal end, and in one embodiment has a different degree of taper than the distal contact zone. In another embodiment, the distal end zone has a more significant or greater degree of taper than that of the distal contact zone. At least an inner surface of the sleeve may be formed from an elastomer layer designed to contact the extremity.
An end zone 7 is directly adjacent to the distal end of the distal contact zone 6, and is also conically shaped so as to taper toward the distal opening 3. In one embodiment, the end section 7 has a more severe or significant degree of taper than the distal contact zone 6 to improve the contact of the sleeve 1 to a prosthetic component (not shown).
In the illustrated embodiment, the sleeve 1 is configured to be donned on a leg such that the distal end zone 7 and possibly some or all of the distal contact zone 6 lies against a prosthetic lower leg component, and the pre-flexed section 5 and proximal contact zone 4 lie against the knee and thigh of a wearer. A drawn-in section 8 lies on the flexor side in the region of the hollow of the knee and a bulge 9 lies on the kneecap. When the leg is flexed, the bulge 9 prevents pressure from being exerted on the kneecap. The drawn-in section 8 allows the sleeve 1 to stretch into the hollow of the knee 1, which reduces or prevents the sleeve material from bunching up and/or wrinkling. The bulge reduces or prevents the sleeve from being drawn too tightly over the relevant joint during flexion.
The pre-flexed angle α, i.e., the angle that is formed between the central axes between the proximal and distal contact zones 4 and 6, is between 50 and 35°, more particularly in the range of between 10° and 25°. The pre-flexed angle α corresponds to the natural flexion behavior of the extremity.
At least a portion, and preferably all, of outer side of the sleeve 1 may be covered with a textile, for example, a textile having a low coefficient of friction. This allows garments to be drawn over the sleeve 1 with reduced friction or sticking. It may also protect the underlying polymer material.
In one embodiment, the proximal contact zone 4 also has a slightly conical shape which widens toward the proximal opening 2 to a less severe or significant degree than the taper of distal end zone 7 and the distal contact zone 6. This reduces or prevents blood flow in the relevant extremity from being impeded.
The prosthetic sleeve 1 of the present invention is particularly useful as a sealing sleeve, which can be pulled over a human extremity and a prosthesis component such as a prosthetic rod or cup to seal the transition zone between the prosthesis and the extremity. For embodiments configured to be secured over a natural or artificial joint. The distal contact zone 6 and distal end zone 7 may taper increasingly toward the distal end to provide a more secure connection at the distal end of the sleeve. If the distal end zone 7 lies at the outer side of a prosthesis rod, the prosthesis rod is held in place particularly securely, with minimal pressure being exerted on the tissue of the amputation stump.
Furthermore, the sleeve 1 is suitable for acting as an additional seal for prosthetic systems operating at low pressure. Such prosthetic systems remove air trapped between a prosthesis rod or receptacle and the amputation stump or a liner pulled over the stump. Air is removed using a vacuum pump and a valve, which forces the air out of the prosthesis rod during a pressure phase. The valve prevents the air from flowing back through the discharge opening. If a sealing sleeve is pulled over the prosthesis rod and the adjacent stump, it seals the interface between the prosthesis rod and the stump, or additionally the interfaces between the prosthesis rod, the liner and the stump. The low pressure may be maintained for a longer period of time using the sleeve, which decreases the likelihood of the rod moving. This gives the user of the prosthetic device a heightened feeling of security and increases acceptance of the prosthesis.
