Evaluation of the Force Sensitive Application Hand Force Measurement System

Abstract

The Force Sensitive Application (FSA) system is used to measure forces exerted by the hand on an object. The present study evaluated the FSA system in terms of stability, repeatability, accuracy, and linearity at the sensor and system (pulp press, pulp pinch, and power grip) levels. At the sensor level, the FSA sensor showed high performance in stability (coefficient of variation [CV] <= 2%) and linearity (coefficient of determination [R-2] = 0.95), but low performance in repeatability (CV =11 similar to 19%) and accuracy (14 similar to 26% overvaluation). At the system level, the FSA system showed a decreasing accuracy (12 similar to 30% undervaluation) as the number of sensors involved in the test increased, but retained a high linearity (R-2 = 0.95 similar to 0.98) to measurement from a dynamometer. These evaluation results indicate that the FSA system should be used for relative, not absolute, comparison in force evaluation due to its lack of accuracy and that the accuracy of the FSA system can be improved due to its good linearity by calibrating FSA measurements with a dynamometer having a high level of accuracy. (C) 2010 Wiley Periodicals, Inc.