A comparison of vibrotactile thresholds on the finger obtained with ISO type equipment and Japanese equipment.

A vibrotactile threshold measurement system that enables the thresholds at the fingertips to be determined more rapidly and precisely has been developed. This system was studied to assess the impact of various factors on the obtained values. An experiment using two different types of equipment was also conducted to assess the repeatability of measurement. One system was similar to that required by International Standard (System A), and the other system was of the currently used in Japan (System B). The subjects were nine males and one female, measurements were taken on three different days. This paper compares the structure of the equipment used internationally (ISO/CD13091) and the equipment typically used in Japan and the measurements of vibrotactile thresholds taken at a 125 Hz frequency using Systems A and B. The measurement method and conditions adopted were almost the same as those outlined in the ISO draft. The results of this experiment showed that there were some differences between the two systems. The vibrotactile thresholds measured using System B showed higher values than did those measured using System A. The results also indicated that equipment that satisfies ISO standards provides sufficient repeatability for use as a diagnostic aid. Also, this paper is shown the vibrotactile measurement equipment conditions must be considered when using vibrotactile threshold measurement equipment in Japan.