The current state of bionic limbs from the surgeon’s viewpoint

Abstract

Amputations have a devastating impact on patients’ health with consequent psychological distress, economic loss, difficult reintegration into society, and often low embodiment of standard prosthetic replacement. The main characteristic of bionic limbs is that they establish an interface between the biological residuum and an electronic device, providing not only motor control of prosthesis but also sensitive feedback. Bionic limbs can be classified into three main groups, according to the type of the tissue interfaced: nerve-transferred muscle interfacing (targeted muscular reinnervation), direct muscle interfacing and direct nerve interfacing. Targeted muscular reinnervation (TMR) involves the transfer of the remaining nerves of the amputated stump to the available muscles. With direct muscle interfacing, direct intramuscular implants record muscular contractions which are then wirelessly captured through a coil integrated in the socket to actuate prosthesis movement. The third group is the direct interfacing of the residual nerves using implantable electrodes that enable reception of electric signals from the prosthetic sensors. This can improve sensation in the phantom limb. The surgical procedure for electrode implantation consists of targeting the proximal nerve area, competently introducing, placing, and fixing the electrodes and cables, while retaining movement of the arm/leg and nerve, and avoiding excessive neural damage. Advantages of bionic limbs are: the improvement of sensation, improved reintegration/embodiment of the artificial limb, and better controllability. Cite this article: EFORT Open Rev 2020;5:65-72. DOI: 10.1302/2058-5241.5.180038

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

“…To accomplish robust control, there are two main challenges: (1) development of neural interfaces that last a long period, and (2) skillful control of the prosthetic device comparable to natural movements [ 168 ]. Up-to-date hand prostheses are actuated by advanced motors, allowing the restoration of fine motor skills with direct muscular signals connection [ 169 ]. In the long run, the goal is to accomplish a quantum-leap advance in neural controllable degrees of autonomy that should permit the user to perform tasks of daily living without effort [ 168 ].…”

“…The need to transmit sensory feedback from the prosthesis [ 187 ] led to the development of the Modular Prosthetic Limb (MPL) with 26 articulated and 17 controllable DOFs with bidirectional capability and the DEKA arm, which provides powered movement complemented by surgical procedures (such as TMSR) for sophisticated control over multiple joints [ 8 ]. Other successful examples of prostheses that allow sensory feedback to enhance motor control include Revolutionizing Prosthetics, the HAPTIX, the Cyberhand, and the NEBIAS [ 169 ]. Lastly, applications of additive technologies in the manufacturing of prosthetic limbs, such as rapid-prototyping (3D printing), are becoming an integral part of UL prostheses [ 188 ], with commercial outcomes such as the Robohand and the Andrianesis’ Hand [ 189 ].…”

Citizenship as the exception to the rule: an addendum

“…Forcing a system out of the human form in a scenario such as this is concerning due to the amount of damage that could be inflicted upon the patient—with death a more-than-likely result in certain cases if not handled in a professional medical environment. This scenario is another such case that will need to be analysed fully by legal scholars and international judiciaries and is arguably one of the most pressing topics that needs to be addressed given the progress of technological implantations worldwide (Saal and Bensmaia 2015; Saadi, Touhami and Yagoub 2017 ; Ha et al 2019 ; Jeong et al 2019 ; Zhuang et al 2019 ; Bumbaširević et al 2020 ).…”

“…These questions are important, as they would transform the landscape of what a work-borne injury is and the requirements expected of one to perform work—notwithstanding participation in professional sports, accelerated academic programmes, and other like events where nootropic or “doping” tactics are currently viewed as cheating or having an unfair advantage (Brown 2013, Bertolini 2015 ; Lee and Read 2018 ; Ruggiu 2018 ; Sullivan 2018 ; Bumbaširević et al 2020 ). Considering CI-dependent assistive bionic prosthetics (CIDABP) 23 from the lens of capability-based ethics, 24 there also may not be a simple answer to this question.…”

“…Regardless of the current bioethical or technoethical discourse surrounding the topic of citizenship for MI-based entities, 2 many medical operations have already been successful in integrating bits of technology into and onto patients internationally (Saal and Bensmaia 2015, Ha et al 2019 ; Jeong et al 2019 ; Zhuang et al 2019 ; Bumbaširević et al 2020 ). 3 Whether in an effort to overcome our human limitations, become more integrated as a society, or remedy an impairment gained through the line of duty or accident (Galván and Luppicini 2014 ; Ruggiu 2018 ; Sullivan 2018 ; Bumbaširević et al 2020 ), the concept of integrating computers and robotics into and onto the human form is rapidly gaining interest. The legal complication herein, regarding HA, 4 is that there is no limit to how much a person can change about their bodies insofar as they possess the sufficient resources to undergo the procedures involved—ethical arguments aside.…”