Bionic hand as artificial organ: Current status and future perspectives

Abstract

Even though the hand comprises only 1% of our body weight, about 30% of our central nervous systems (CNS) capacity is related to its control. The loss of a hand thus presents not only the loss of the most important tool allowing us to interact with our environment, but also leaves a dramatic sensory-motor deficit that challenges our CNS. Reconstruction of hand function is therefore not only an essential part of restoring body integrity and functional wholeness but also closes the loop of our neural circuits diminishing phantom sensation and neural pain. If biology fails to restore meaningful function, today we can resort to complex mechatronic replacement that have functional capabilities that in some respects even outperform biological alternatives, such as hand transplantation. As with replantation and transplantations, the challenge of bionic replacement is connecting the target with the CNS to achieve natural and intuitive control. In recent years, we have developed a number of strategies to improve neural interfacing, signal extraction, interpretation and stable mechanical attachment that are important parts of our current research. This work gives an overview of recent advances in bionic reconstruction, surgical refinements over technological interfacing, skeletal fixation, and modern rehabilitation tools that allow quick integration of prosthetic replacement. K E Y W O R D Sbionic reconstruction, hybrid fitting, interface, osseointegration, prostheses, rehabilitation, targeted muscle reinnervation 110 | AMAN et Al. meets the supreme principle to reconstruct "like with like" best, as it offers a hand of flesh and blood with immediate, intuitive proprioceptive motor control, sensory feedback, and a sense of ownership that at this time cannot be achieved by any prosthetic device.Aside from bionic reconstruction with myoelectric prostheses, controlled by at least 2 electromyography (EMG) signals from remnant stump muscles, also passive, bodypowered devices are used in prosthetic reconstruction. Passive prostheses range from stable or adjustable cosmetic hands, with silicone cover and natural appearance, to prosthetic tools, which are mainly hooks or grasping devices. 5 Socalled body-powered prostheses can perform simple grasping tasks by external cables attached to the prosthetic arm, driven by body movement. This serves as an assistant hand to the dominant hand, but it is obviously not capable of performing different grasps or hand movements.

Hand Bionic Score: a clinical follow-up study of severe hand injuries and development of a recommendation score to supply bionic prosthesis

“…Quality of life and hand function showed poor to very poor results. Hand Bionic Score was 19, recommending a bionic prosthesis fitting with amputation of the nonfunctioning hand radically [63]. For instance, a special topic is sensation of the prosthesis-while currently available prostheses need visual feedback to control movements, further development of prosthesis sensation could improve dexterity of prosthetic hands [64].…”

Single Incision Thenar Muscle Reconstruction Using the Free Functional Pronator Quadratus Flap

“…Opposition movement of the thumb is the crucial function which makes the human hand unique. Accordingly, impairment is not only disastrous for accomplishing daily life activities and occupational tasks, sometimes leading to psychological burden, but also has socioeconomic consequences (15).…”

Artificial Organs 2019: A year in review

“…Martin Aman et al of the Medical University of Vienna, Vienna, Austria reported on their efforts to restore meaningful function to the hand by complex mechatronic replacement that have functional capabilities that in some respects even outperform biological alternatives. As with replantation and transplantations, the challenge of bionic replacement is connecting the target with the central nervous system to achieve natural and intuitive control.…”