Vibrotactile TTS of fingertip vibratory sensation from hand-transmitted vibration having the same equal equivalent tool vibration levels according to the JIS B 4900 determination method.

The purpose of this paper is to clarify the temporary threshold shifts in fingertip vibratory sensation produced by hand-transmitted vibrations that have the same equivalent tool vibration levels according to the JIS B 4900 determination method. The JIS B 4900 standard is based on vibration exposure dose values. Therefore, even though the vibration exposure pattern is varied, the severity of vibration at the end of vibration exposure has a same value if the equivalent tool vibration level is unchanged. The experiment was conducted by using four kinds of hand-transmitted vibration patterns as stimuli. As a result, although the vibration transmitted to the hand by steady continuous vibration, intermittent vibration with short pauses, intermittent vibration with long pauses and repeated single bursts of vibration all have the same equivalent tool vibration levels (equal vibration exposure dose value) according to the JIS B 4900 determination method, the TTS after vibration exposure did not produce the same value. Therefore, these results suggest that the determination methods of the JIS B 4900 standard are not adequate for describing the vibration exposure dose value.