Piezoresistive foot pressure measurement method and apparatus

摘要

PCT No. PCT/IB96/01467 Sec. 371 Date May 13, 1998 Sec. 102(e) Date May 13, 1998 PCT Filed Nov. 14, 1996 PCT Pub. No. WO97/18450 PCT Pub. Date May 22, 1997A method and apparatus (68, 40) for measuring pressures exerted on 6 human feet or horses' hooves comprises a rectangular array of piezoresistive force sensors encapsulated in a thin polymer package (40) that is inserted into a shoe, or incorporated into a sock that may be pulled over a foot or hoof. The preferred embodiment employs novel piezoresistive normal force or pressure sensing elements (36) which include a polymer fabric mesh impregnated with conductive particles suspended in an elastomeric vehicle, preferably silicone rubber. The piezoresistive mesh layer (33) is sandwiched between an array of row (34) and column (31) conductor strip laminations, preferably made of a nylon mesh impregnated with printed metallic paths. In a variation (100) of the basic embodiment, each normal force sensor element (30) is bordered by laterally and longitudinally disposed pairs (80) of shear force sensor elements, each of the latter comprising a pair of adjacent resilient piezoresistive pads (83) that have longitudinally contacting lateral surfaces. The pads are slidably movable, and when urged into more or less intimate contact in response to shear forces directed normal to their tangent contact plane, the electrical resistance between the pads varies in a predetermined way as a function of the shear forces.