Interfaces with the peripheral nervous system for the control of a neuroprosthetic limb: a review

Abstract

The field of prosthetics has been evolving and advancing over the past decade, as patients with missing extremities are expecting to control their prostheses in as normal a way as possible. Scientists have attempted to satisfy this expectation by designing a connection between the nervous system of the patient and the prosthetic limb, creating the field of neuroprosthetics. In this paper, we broadly review the techniques used to bridge the patient's peripheral nervous system to a prosthetic limb. First, we describe the electrical methods including myoelectric systems, surgical innovations and the role of nerve electrodes. We then describe non-electrical methods used alone or in combination with electrical methods. Design concerns from an engineering point of view are explored, and novel improvements to obtain a more stable interface are described. Finally, a critique of the methods with respect to their long-term impacts is provided. In this review, nerve electrodes are found to be one of the most promising interfaces in the future for intuitive user control. Clinical trials with larger patient populations, and for longer periods of time for certain interfaces, will help to evaluate the clinical application of nerve electrodes.

Temporal patterns in electrical nerve stimulation: Burst gap code shapes tactile frequency perception

“…The present study used external electrodes to stimulate the digital nerve and confirm the burst gap phenomenon for frequency encoding, albeit with a small frequency shift compared with mechanical activation. The use of intrafascicular stimulation with multi-electrode arrays could activate nerve fascicles which may have a more restricted range of afferent types, in addition to offering improved spatial resolution [29,59]. It would be interesting to see whether predominantly FA-containing fascicles show frequency responses that are a closer match to the results with mechanical stimulation in our previous study.…”

“…This raises the possibility that the burst gap code that we observed with mechanical stimulation is in some way dependent on these spatial activation patterns and/or predominant activation of certain afferent types. As an alternative, electrical stimulation is a robust method to reliably activate axons, and a simple technique to implement in neuroprosthetic interfaces [ 29 ] or haptic displays [ 30 ]. Thus, in this study we aimed to use electrical stimuli to directly evoke spike trains in tactile afferent fibres while avoiding complex mechanical skin phenomena and establish the burst gap model for frequency perception.…”

Converging Robotic Technologies in Targeted Neural Rehabilitation: A Review of Emerging Solutions and Challenges

“…Such a device can be a wearable exoskeleton or a prosthetic/bionic device [7]. The technologies mentioned in this section interface either directly (digital-neural interfaces) or indirectly (EMG interfaces) with the PNS or with the CNS (BCIs) [101,102]. Such technologies use a physical interface via electrodes that based on invasiveness can be discriminated into either implantable (applied directly at the brain/muscle/nerve) or surface (applied on the skin) devices [102].…”

“…Interfacing with the PNS via neural electrodes is considered one of the most promising ways to control sophisticated neuroprosthetics [102]. For direct physical interfacing with the nerves, there are two main types of electrodes-namely, extraneural (placed around the nerve) and intraneural (inserted inside the nerve) [101,102].…”

Control Methods for Transradial Prostheses Based on Remnant Muscle Activity and Its Relationship with Proprioceptive Feedback

“…The majority of currently used methods (direct and indirect) measure changes of physiological parameters of muscles during activity to obtain control signals for the prosthesis [ 38 ]. In the meantime, the actively developing field of the brain–machine interface and connection to peripheral nervous system represents a different set of approaches [ 39 , 40 ]. This review focuses on the prevalent group of biosensing methods based on the measurement of the activity of residual muscles.…”