Evaluation of a sensor for low interface pressure applications

An ultra-thin, small sensor has recently been developed, "FlexiForce" (Teks can, Boston, MA, USA), which may be effective for the measurement of low in terface pressure between the skin, support surfaces and pressure garments. To evaluate the suitability of the sensor for these applications, drift, re peatability, linearity, hysteresis and curvature effects were tested under laboratory conditions. The drift was 1.7-2.5%/logarithmic time, the repeatability was 2.3-6.6% and the linearity was 1.9-9.9% in the range of forces of 10-50 g applied. The hysteresis was 5.4% on average. The output offset of the sensor increased w ith decreasing radius of curvature for radii less than 32 mm compared with a flat surface when no pressure was applied. The sensitivity to pressure de creased with curvature for radii less than 32 mm, It was found that the sensor had acceptable drift, repeatability, linearity and hysteresis. However, a significant curvature effect was observed indic ating that the sensor is suitable for direct measurement on surfaces with t he radii greater than 32 mm under static conditions. (C) 2001 IPEM. Publish ed by Elsevier Science Ltd. All rights reserved.