Haptic shared control improves neural efficiency during myoelectric prosthesis use

Abstract

Clinical myoelectric prostheses lack the sensory feedback and sufficient dexterity required to complete activities of daily living efficiently and accurately. Providing haptic feedback of relevant environmental cues to the user or imbuing the prosthesis with autonomous control authority have been separately shown to improve prosthesis utility. Few studies, however, have investigated the effect of combining these two approaches in a shared control paradigm, and none have evaluated such an approach from the perspective of neural efficiency (the relationship between task performance and mental effort measured directly from the brain). In this work, we analyzed the neural efficiency of 30 non-amputee participants in a grasp-and-lift task of a brittle object. Here, a myoelectric prosthesis featuring vibrotactile feedback of grip force and autonomous control of grasping was compared with a standard myoelectric prosthesis with and without vibrotactile feedback. As a measure of mental effort, we captured the prefrontal cortex activity changes using functional near infrared spectroscopy during the experiment. It was expected that the prosthesis with haptic shared control would improve both task performance and mental effort compared to the standard prosthesis. Results showed that only the haptic shared control system enabled users to achieve high neural efficiency, and that vibrotactile feedback was important for grasping with the appropriate grip force. These results indicate that the haptic shared control system synergistically combines the benefits of haptic feedback and autonomous controllers, and is well-poised to inform such hybrid advancements in myoelectric prosthesis technology.

A Wearable Bidirectional Human–Machine Interface: Merging Motion Capture and Vibrotactile Feedback in a Wireless Bracelet

“…Additionally, the need for visual attention decreases as the movements of the virtual or robotic limb can be registered through haptic feedback by itself or in addition. This leads to lower cognitive loads for users, allowing for them to accomplish the tasks with higher precision and ease, as shown in a recent study by Thomas et al [3], who examined an improvement in neural efficiency when using haptic-shared control for myoelectric prostheses. The results of another study suggest that both sensory and motor inputs play an equal role in shaping the representation of spatial body coordinates, and these coordinates are susceptible to multisensory enhancing effects [4].…”

Muscle Oximetry in Sports Science: An Updated Systematic Review

“…Different lightweight (about 20 g), compact, smartphone-controllable and wearable multi-distance CW-NIRSbased oximeters with Bluetooth connection up to 150 m and on-board data collection (up to 50 h) are commercially available [236]. The novel CW-NIRS oximeter (Train.Red Plus, Artinis Medical Systems) also includes very useful haptic feedback, so that the subject can feel a buzzer on the skin during the exercise [237]. The CW-NIRS technology has been incorporated into OctaMon M (Artinis Medical Systems), the only commercial imager dedicated to muscle studies (50 Hz sampling time; four source-detector distances in the range 25-40 mm) using eight measurement points [238].…”