Long-term implant of intramuscular sensors and nerve transfers for wireless control of robotic arms in above-elbow amputees

S Salminger; A Sturma; C Hofer; M Evangelista; M Perrin; K D Bergmeister; A D Roche; T Hasenoehrl; H Dietl; D Farina; O C Aszmann

doi:10.1126/scirobotics.aaw6306

Long-term implant of intramuscular sensors and nerve transfers for wireless control of robotic arms in above-elbow amputees

Sci Robot. 2019 Jul 17;4(32):eaaw6306. doi: 10.1126/scirobotics.aaw6306.

Authors

S Salminger^{1

2}, A Sturma^{2

3}, C Hofer^{2

4}, M Evangelista⁵, M Perrin⁵, K D Bergmeister^{1

2}, A D Roche^{2

6

7}, T Hasenoehrl⁸, H Dietl⁴, D Farina³, O C Aszmann^{9

2}

Affiliations

¹ Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
² Christian Doppler Laboratory for Restoration of Extremity Function, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
³ Department of Bioengineering, Royal School of Mines, Imperial College London, South Kensington Campus, Kensington, London SW7 2AZ, UK.
⁴ Otto Bock Healthcare Products GmbH, Brehmstraße 16, A-1110 Vienna, Austria.
⁵ Alfred Mann Foundation, 25134 Rye Canyon Loop #200, Valencia, CA 91355, USA.
⁶ Deanery of Clinical Sciences, The University of Edinburgh, Scotland, UK.
⁷ Department of Plastic & Reconstructive Surgery, NHS Lothian, Scotland, UK.
⁸ Department of Physical Medicine and Rehabilitation, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria.
⁹ Division of Plastic and Reconstructive Surgery, Department of Surgery, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria. oskar.aszmann@meduniwien.ac.at.

PMID: 33137771
DOI: 10.1126/scirobotics.aaw6306

Abstract

Targeted muscle reinnervation (TMR) amplifies the electrical activity of nerves at the stump of amputees by redirecting them in remnant muscles above the amputation. The electrical activity of the reinnervated muscles can be used to extract natural control signals. Nonetheless, current control systems, mainly based on noninvasive muscle recordings, fail to provide accurate and reliable control over time. This is one of the major reasons for prosthetic abandonment. This prospective interventional study includes three unilateral above-elbow amputees and reports the long-term (2.5 years) implant of wireless myoelectric sensors in the reinnervation sites after TMR and their use for control of robotic arms in daily life. It therefore demonstrates the clinical viability of chronically implanted myoelectric interfaces that amplify nerve activity through TMR. The patients showed substantial functional improvements using the implanted system compared with control based on surface electrodes. The combination of TMR and chronically implanted sensors may drastically improve robotic limb replacement in above-elbow amputees.