Orthosis knee joint and sensor

A method for selectively operating an orthotic device associated with the joint of a person comprising:

• (a) providing a thin elongated layer of variably electrically resistive material capable of changing electrical resistance responsive to a change in the application of a force above a threshold force to at least a portion of said layer, said layer having opposing upper and lower surfaces;
• (b) electrically contacting a conductive element with said surfaces;
• (c) generating a control signal with an electronic circuit operatively connected to the conductive element when a threshold force is applied to the variably electrically resistive material;
• and
• (d) selectively switching the mechanism of an orthotic device from one state to another state in response to the control signal.

A selectively operable orthotic device comprising:

• (a) a thin elongated layer of variably electrically resistive material capable of decreasing electrical resistance responsive to the application of a force above a threshold force to at least a portion of said layer, said layer having opposing upper and lower surfaces;
• (b) a conductive element in electrical contact with said surfaces;
• (c) an electronic circuit operatively connected to said conductive element, said circuit generating a control signal when an actuating force is applied to said variably electrically resistive material;
• and
• (d) an orthotic device operatively connected to said electronic circuit, said device having a mechanism selectively switchable from one state to another state in response to said signal.