Myoelectric Prosthetic Hand with Sensory Feedback that Generates Discomfort

The aim of this study is to develop a new tactile feedback method for myoelectric prosthetic hands. The sense of touch can be reproduced such as by vibrating actuators based on information from a sensor attached to the fingertip of the myoelectric prosthetic hand. This paper attempted to use delayed vibration feedback to create discomfort as a corresponding sensation to pain since a prior study has found that a time lag between sensory input and stimulation can cause discomfort. In the experiment carried out, we first examine the relationship between the delay time D and sensation in vibration stimulation. The experimental results indicated that discomfort occurs between D = 0.25 seconds and 0.65 seconds. Furthermore, to verify whether the proposed feedback method can be used to discriminate between normal objects and dangerous objects such as knives, we applied it to the haptic feedback of a prosthetic hand controlled by myoelectric signals. The results showed that the participant could recognize the difference in feedback and distinguish between the two types of objects with an accuracy of 95.0 +/- 0.1%.