The design of a finger wear simulator and preliminary results

A dual-cycle finger wear simulator has been designed, manufactured and comm issioned. The simulator interspersed dynamic flexion-extension motion under light load with a heavier static 'pinch' load to a test prosthesis immerse d in a lubricant heated to 37 degreesC. A validation test was undertaken on a size 2 Swanson prosthesis, leading to prosthesis failure in less than mi llion cycles. A second test was carried out on a Durham metacarpophalangeal prosthesis. After 4.8 million cycles a total wear factor for the joint of 0.60 x 10(-6) mm(3)/N m was calculated, with no cracks or damage visible. B oth test results compare well with earlier tests undertaken on the Stokoe f inger wear simulator.