关键词: TENS , · Prosthetic hand control , · Bioinspired sensation , · Multimodal sensations , · Proprioception feedback , · Tactile feedback , · Myoelectric control

Abstract: Tactile and proprioception feedback are essential to myoelectric hand prostheses control for regaining functionality of lost hands of amputees. Current studies focus on tactile feedback, while the lack of appropriate multisensory feedback, especially proprioception feedback, limits the grasping quality. Additionally, a typical non-invasive stimulation scheme for sensation feedback uses stimulation on the stationary site of the skin continuously, which can lead to fatigue and adaptation of sensation, further reduces the feedback consistency, and increases the cognitive burden for the subject. Considering the sensitivity and modality matching of sensation, this study presented a multimodal sensations feedback scheme based on hybrid static-dynamic sensation elicited by multisite Transcutaneous Electrical Nerve Stimulation (TENS) to deliver grasping force and joint position feedback. In the proposed scheme, stimulation of single electrode produced only in-loco tactile sensation under the electrode, and the sensation intensity was adjusted according to grasping force; sequential activation of multi-electrodes produced an illusion dynamic sensation of a stimulus moving, and the velocity and direction of movement were adjusted according to finger joint position. Psychometric test results demonstrated the identifiability of stimulus in the proposed scheme. Further, prosthetic hand closed-loop grasping tasks evaluate the effectiveness of the proposed feedback scheme. The results showed that the proposed feedback scheme could substantially improve the grasping accuracy and efficiency. In addition, the study outcomes also demonstrated the benefit of artificial proprioception feedback in grasping rapidity and security.

Key words: TENS , · Prosthetic hand control , · Bioinspired sensation , · Multimodal sensations , · Proprioception feedback , · Tactile feedback , · Myoelectric control