A cosmetic prosthetic digit with bioinspired embedded touch feedback

Abstract

Partial hand amputation is the most frequent amputation level worldwide, accounting for approximately 90% of all upper limb amputations. Passive cosmetic prostheses represent one of the possible choices for its treatment, probably the most affordable one. However, these devices restore very limited motor function and subtle sensory feedback. The latter is an important component for restoring the body schema. In this work we present a simple yet potentially effective and low cost cosmetic digital prosthesis that embeds touch feedback; we dubbed this DESC-finger. It delivers short-lasting vibrotactile bursts when it makes and breaks contact with the environment, based on the Discrete Event-driven Sensory feedback Control (DESC) policy. One prototype was developed and used by one amputee at home, for two months. The effectiveness of the device was experimentally assessed by means of an interview and a virtual eggs test, which showed, albeit preliminarily, that time discrete feedback can improve the motor control of a partial hand prosthesis in daily life conditions. Besides targeting people that already use cosmetic digits, the DESC-finger targets those that do not use them complaining for loss of sensibility. The production costs and manufacturing process makes the DESC-finger suitable for exploitation in high- and low-income countries.

When Less Is More – Discrete Tactile Feedback Dominates Continuous Audio Biofeedback in the Integrated Percept While Controlling a Myoelectric Prosthetic Hand

“…To this aim we assessed and compared four sensory feedback conditions while controlling a myoelectric research hand prosthesis in psychophysical and functional tests. The three main conditions differed regarding the amount of complementary information: “visual-only (V),” “visual-plus-audio (VA),” and “visual-plus-audio-plus-tactile (VAT).” To disentangle the effects of the tactile component on the outcomes of the VAT feedback, the fourth condition was “visual-plus-tactile (VT).” The tactile feedback was provided by means of short-lasting vibrotactile cues (time-discrete) rather than continuous feedback, according to our previous work (Cipriani et al, 2014; Crea et al, 2015; Clemente et al, 2016; Barone et al, 2017; Aboseria et al, 2018) and the discrete event-driven sensory feedback control (DESC) policy (Johansson and Cole, 1992; Johansson and Edin, 1993; Johansson and Flanagan, 2009). The latter is a neuroscientific hypothesis of the mechanisms involved in human sensorimotor control, which posits that manipulation tasks are organized by means of multi-modally encoded discrete sensory events, e.g., resulting from object contact and lift-off.…”

Osseointegrated Metallic Implants for Finger Amputees: A Review of the Literature

“…Currently, none of the presented studies can restore sensorial feedback in addition to osseoperception. A concrete future development related to osseointegrated prosthesis is supported in one study, 69 whose authors developed a cosmetic finger capable of reading force information to convert them in a vibrotactile stimulation on the stump. The lack of this aspect in osseointegrated implants for fingers is clear.…”

Current and emerging prostheses for partial hand amputation: A narrative review

“…A passive prosthesis can also be made “smart” by embedding proprioceptive feedback. An example of the research effort is the Discrete Event‐driven Sensory feedback Control (DESC), which delivers short‐lasting vibrotactile bursts when it makes and breaks contact with the environment 33 …”