Grip control and motor coordination with implanted and surface electrodes while grasping with an osseointegrated prosthetic hand
Journal article, 2019

Background: Replacement of a lost limb by an artificial substitute is not yet ideal. Resolution and coordination of motor control approximating that of a biological limb could dramatically improve the functionality of prosthetic devices, and thus reduce the gap towards a suitable limb replacement.

Methods: In this study, we investigated the control resolution and coordination exhibited by subjects with transhumeral amputation who were implanted with epimysial electrodes and an osseointegrated interface that provides bidirectional communication in addition to skeletal attachment (e-OPRA Implant System). We assessed control resolution and coordination in the context of routine and delicate grasping using the Pick and Lift and the Virtual Eggs Tests. Performance when utilizing implanted electrodes was compared with the standard-of-care technology for myoelectric prostheses, namely surface electrodes.

Results: Results showed that implanted electrodes provide superior controllability over the prosthetic terminal device compared to conventional surface electrodes. Significant improvements were found in the control of the grip force and its reliability during object transfer. However, these improvements failed to increase motor coordination, and surprisingly decreased the temporal correlation between grip and load forces observed with surface electrodes. We found that despite being more functional and reliable, prosthetic control via implanted electrodes still depended highly on visual feedback.

Conclusions: Our findings indicate that incidental sensory feedback (visual, auditory, and osseoperceptive in this case) is insufficient for restoring natural grasp behavior in amputees, and support the idea that supplemental tactile sensory feedback is needed to learn and maintain the motor tasks internal model, which could ultimately restore natural grasp behavior in subjects using prosthetic hands.

Epimysial

Implanted electrodes

Prosthetic control

Electromyography (EMG)

Osseointegration

Author

Enzo Mastinu

Chalmers, Electrical Engineering, Signalbehandling och medicinsk teknik, Biomedical Signals and Systems

Francesco Clemente

Sant'Anna School of Advanced Studies (SSSUP)

Paolo Sassu

Sahlgrenska University Hospital

Oskar C. Aszmann

Center for Medical Statistics, Informatics, and Intelligent Systems, Medical University of Vienna

Rickard Brånemark

University of Gothenburg

Bo Håkansson

Chalmers, Electrical Engineering, Signalbehandling och medicinsk teknik, Biomedical Signals and Systems

Marco Controzzi

Sant'Anna School of Advanced Studies (SSSUP)

Christian Cipriani

Sant'Anna School of Advanced Studies (SSSUP)

Max Jair Ortiz Catalan

Chalmers, Electrical Engineering, Signalbehandling och medicinsk teknik, Biomedical Signals and Systems

Journal of NeuroEngineering and Rehabilitation

1743-0003 (ISSN)

Subject Categories

Physiotherapy

Medical Engineering

Other Materials Engineering

Embedded Systems

Signal Processing

DOI

10.1186/s12984-019-0511-2

More information

Latest update

6/17/2019