The Utility of Synthetic Reflexes and Haptic Feedback for Upper-Limb Prostheses in a Dexterous Task Without Direct Vision

Abstract

Individuals who use myoelectric upper-limb prostheses often rely heavily on vision to complete their daily activities. They thus struggle in situations where vision is overloaded, such as multitasking, or unavailable, such as poor lighting conditions. Able-bodied individuals can easily accomplish such tasks due to tactile reflexes and haptic sensation guiding their upper-limb motor coordination. Based on these principles, we developed and tested two novel prosthesis systems that incorporate autonomous controllers and provide the user with touch-location feedback through either vibration or distributed pressure. These capabilities were made possible by installing a custom contact-location sensor on the fingers of a commercial prosthetic hand, along with a custom pressure sensor on the thumb. We compared the performance of the two systems against a standard myoelectric prosthesis and a myoelectric prosthesis with only autonomous controllers in a difficult reach-to-pick-and-place task conducted without direct vision. Results from 40 able-bodied participants in this between-subjects study indicated that vibrotactile feedback combined with synthetic reflexes proved significantly more advantageous than the standard prosthesis in several of the task milestones. In addition, vibrotactile feedback and synthetic reflexes improved grasp placement compared to only synthetic reflexes or pressure feedback combined with synthetic reflexes. These results indicate that autonomous controllers and haptic feedback together facilitate success in dexterous tasks without vision, and that the type of haptic display matters.

Haptic shared control improves neural efficiency during myoelectric prosthesis use

“…Although such a system can be tested, careful consideration should be given to the method of communicating to the user which operating mode they are in without overburdening their visual or auditory senses. Based on our prior work 38 , we would expect that the haptic shared-control approach will lead to improved neural-efficiency over the shared-control approach without haptic feedback.…”

“…Likewise, the amplitude of wrist extension activity is proportional to the opening speed of the prosthesis. The control equation and more details can be found in our previous study 38 ; the only difference here is the range of voltages used to drive the current prosthesis (1.5–7 V here instead of 0.55–1.5 V in our prior work).…”

“…Haptic shared control techniques, for example, have been incorporated in automotive applications, where haptic feedback from the autonomous system guides the driver during navigation [33][34][35][36][37] . In our prior work, we developed a haptic shared control approach for an upper limb prosthesis and investigated its task performance utility in a dexterous reach-to-pick-and-place task without direct vision 38 . In this manuscript, we build on this prior study by investigating the extent to which haptic shared control improves neural efficiency in a dexterous task.…”

Biorealistic hand prosthesis with compliance control and noninvasive somatotopic sensory feedback

“…Thus, restoring humanlike neuromuscular reflex control in prosthetic hands may provide a greater neural compatibility to human sensorimotor control [7,8]. In previous studies, auto-reflex via detected information of external environment was used to enhance the function of prosthetic hands [193][194][195]. However, the focus of this section is on the recent development of a novel biorealistic computational modeling approach to restoring neuromuscular reflex control for a prosthetic hand.…”

Exploring the influence of anthropomorphic appearance on usage intention on online medical service robots (OMSRs): A neurophysiological study

“…Currently, robots are becoming ever more prevalent in medical services [ [7] , [8] , [9] ]. These robots perform a wide range of tasks, including electrophysiology sensing [ 8 ], robotic technology in foot and ankle surgery [ 10 ], and prosthetic tasks [ 9 ]. With the development of wireless networks and devices, medical robots have transitioned to OMSRs.…”