Sensory feedback in upper limb prosthetics

Abstract

One of the challenges facing prosthetic designers and engineers is to restore the missing sensory function inherit to hand amputation. Several different techniques can be employed to provide amputees with sensory feedback: sensory substitution methods where the recorded stimulus is not only transferred to the amputee, but also translated to a different modality (modality-matched feedback), which transfers the stimulus without translation and direct neural stimulation, which interacts directly with peripheral afferent nerves. This paper presents an overview of the principal works and devices employed to provide upper limb amputees with sensory feedback. The focus is on sensory substitution and modality matched feedback; the principal features, advantages and disadvantages of the different methods are presented.

Humans can integrate feedback of discrete events in their sensorimotor control of a robotic hand

“…However, despite various attempts to provide sensory feedback and closed-loop control of hand prostheses over the years, none has been proven functional and thus been deployed in clinical practice (Antfolk et al 2013). In all previous attempts, feedback was provided in a continuous fashion, e.g., by mapping grip force to a certain vibration frequency (Mann and Reimers 1970;Chatterjee et al 2008;Cipriani et al 2008;Stepp et al 2012), a mechanical stimulus (Meek et al 1989;Antfolk et al 2012), or an electrical current (Szeto and Saunders 1982;Sasaki et al 2002).…”

A System for Electrotactile Feedback Using Electronic Skin and Flexible Matrix Electrodes: Experimental Evaluation

“…However, a bilateral communication between the brain and the periphery, including both efferent and afferent information flow, is necessary for the human movement learning and execution [3]. Closing the prosthesis control loop by providing sensory feedback to the user is a key point in research on active prosthetics [4], [5] as well as an often cited requirement of the prosthesis users [6]. Nevertheless, apart from one recent example [7], there are still no commercially-available prostheses transmitting somatosensory information back to the user.…”

“…Regarding the stimulation interfaces, non-invasive methods are still most common [5]. Most studies [28]- [30] considered single stimulation units with parameter modulation (e.g., frequency and intensity proportional to the feedback variable value) and a few [31]- [33] evaluated multichannel approaches using several electrodes or vibrators allowing for the spatial coding (e.g., stimulation location communicates the feedback variable).…”

“…Although the concept of applying e-skin technology for somatosensory feedback in prosthetics has been proposed earlier [5], the present study is the first evaluation of an online system implementing the prospective communication link, i.e., the information transmission from e-skin to the human subject.…”

Key considerations in designing a somatosensory neuroprosthesis

“…In light of this, efforts have been underway to develop approaches to convey somatosensory feedback (Bensmaia, 2015;Bensmaia and Miller, 2014;Flesher et al, 2016;Graczyk et al, 2016;Saal and Bensmaia, 2015). One family of approaches -sensory substitution -consists of applying mechanical stimuli, typically skin vibrations, to an intact and sensate patch of skin somewhere on the body and modulate the activation of these tactors according to the movements of the prosthesis and/or its contact with objects (Antfolk et al, 2013). While this approach achieves some success in laboratory settings with contrived experimental tests, it fails catastrophically as soon as subjects/patients divide their attention between hand use and other tasks, a common requirement during activities of daily living.…”