Mechanotactile Sensory Feedback Improves Embodiment of a Prosthetic Hand During Active Use

Abstract

There have been several advancements in the field of myoelectric prostheses to improve dexterity and restore hand grasp patterns for persons with upper limb loss, including robust control strategies, novel sensory feedback, and multifunction prosthetic terminal devices. Although these advancements have shown to improve prosthesis performance, a key element that may further improve acceptance is often overlooked. Embodiment, which encompasses the feeling of owning, controlling and locating the device without the need to constantly look at it, has been shown to be affected by sensory feedback. However, the specific aspects of embodiment that are influenced are not clearly understood, particularly when a prosthesis is actively controlled. In this work, we used a sensorized simulated prosthesis in able-bodied participants to investigate the contribution of sensory feedback, active motor control, and the combination of both to the components of embodiment; using a common methodology in the literature, namely the rubber hand illusion (RHI). Our results indicate that (1) the sensorized simulated prosthesis may be embodied by able-bodied users in a similar fashion as prosthetic devices embodied by persons with upper limb amputation, and (2) mechanotactile sensory feedback might not only be useful for improving certain aspects of embodiment, i.e., ownership and location, but also may have a modulating effect on other aspects, namely sense of agency, when provided asynchronously during active motor control tasks. This work may allow us to further investigate and manipulate factors contributing to the complex phenomenon of embodiment in relation to active motor control of a device, enabling future study of more precise quantitative measures of embodiment that do not rely as much on subjective perception.

Recurrent Convolutional Neural Networks as an Approach to Position-Aware Myoelectric Prosthesis Control

“…These movements are functionally important for individuals with transradial amputation [37]. Notably, the hand open and close movements were not included in this study, given that wrist flexion and extension can instead be used to control the opening and closing of a prosthetic hand [31], [38]- [41]. Similarly, forearm pronation and supination can be used to control prosthetic wrist rotation.…”

The rubber hand illusion is a fallible method to study ownership of prosthetic limbs

“…This finding is consistent with contemporary work by Shehata et al . 39 , where tapping was used to induced ownership of a passive prosthesis worn by able-bodied participants. Furthermore, we showed that a small stimulation area was sufficient for a successful RHI.…”

A Modular Adjustable Transhumeral Prosthetic Socket for Evaluating Myoelectric Control

“…Additional straps can be mounted to add additional mounting points. These mounting points could also be used to integrate sensory feedback systems, such as mechanotactile tactors [5] , [23] and vibrotactile tactors [13] , [24] (see Figure 3 ). Interior Cushions: Cushions provide a compliant fit to conform with and support the wearer’s residual limb.…”