Precision method of evaluating the tactile response based on the Levitation Mass Method

This paper proposes a precision method of evaluating the tactile response. The method is based on the "levitation mass method" (LMM). Generating and/or measuring the dynamic force without use of force transducers is realized using the LMM. In the experiment, a mass that is levitated with a pneumatic linear bearing, and hence encounters negligible friction, is made to collide with a human arm. During the collision, the Doppler frequency shift of a laser beam reflecting from the mass is accurately measured using an optical interferometer. The velocity, position, acceleration and inertial force of the mass are calculated from the measured time-varying Doppler shift. The LMM is characterized by the fact that preparation for the test is easy and the measurement accuracy is high. In the proposed method, the information obtained from the subject\´s tactile sense is compared with the experimental information (i.e., measurement value). The possibility of using the method for biomedical engineering is discussed