Osmotic membrane and vacuum system for artificial limb
A system for removing perspiration from a residual limb inserted in a prosthesis comprising an nonporous prosthesis socket, a porous thin sheath adjacent the socket, a nonporous liner adjacent the sheath, an osmotic membrane adjacent the liner allowing water vapor to pass from the limb but preventing liquid from passing to the limb, a nonporous seal that prevents air leakage between the residual limb and the socket; and, a vacuum source to reduce the pressure in a space between the limb and socket. A method of removing perspiration from a residual limb in a prosthesis.
1. A system for removing perspiration from a residual limb inserted in a prosthesis comprising:
a nonporous prosthesis socket;
a porous thin sheath adjacent the socket;
a nonporous liner adjacent the sheath;
an osmotic membrane adjacent the liner allowing water vapor to pass from the limb but preventing liquid from passing to the limb;
a nonporous seal that prevents air leakage between the residual limb and the socket; and
a vacuum source to reduce the pressure in a space between the limb and socket.
2. The system of claim 1 wherein the nonporous seal is a nonfoamed, nonporous polyurethane suspension sleeve.
3. The system of claim 1 , wherein the vacuum source is a vacuum pump, a regulator and a power source.
4. The system of claim 1 , wherein the vacuum source is a weight-actuated vacuum pump.
5. The system of claim 1 , where in the sheath is a porous, knitted nylon material.
6. The system of claim 1 , wherein the liner is nonfoamed, nonporous polyurethane.
7. A method of removing perspiration from a residual limb in a prosthesis comprising the steps of:
inserting the residual limb into a sleeve comprising an osmotic membrane that allows water vapor to pass from the limb but preventing liquid from passing to the limb;
inserting the residual limb and osmotic membrane sleeve into a flexible, nonporous liner;
inserting the residual limb, osmotic membrane sleeve and liner into a porous sheath;
inserting the residual limb, osmotic membrane sleeve, liner and sheath into a prosthetic socket cavity having a volume and shape to receive the residual limb;
sealing the socket cavity with a nonporous seal; and
applying a vacuum to the socket cavity in the space between the membrane and the socket to draw the residual limb and liner into firm contact with the socket and provide a reduced pressure in the socket cavity.
8. The method of claim 7 , further comprising the step of maintaining the vacuum in the socket cavity, in the presence of some air leakage into the socket cavity.
9. The method of claim 7 , wherein the sheath is a porous knitted nylon material.
10. The method of claim 7 , wherein the liner is of a nonfoamed, nonporous polyurethane.
11. The method of claim 7 , wherein the nonporous seal is nonfoamed, nonporous polyurethane suspension sleeve.
12. The method of claim 7 , wherein the vacuum source is a vacuum pump, a regulator and a power source.
13. The method of claim 7 , wherein the vacuum source is a weight-actuated vacuum pump.
14. The method of claim 7 , wherein a vacuum of at least ten inches of mercury is maintained in the socket cavity.