Invasive Myoelectric Control
Current prosthetic devices lack independent command sites due to muscle crosstalk as signals are measured on the skin surface, allowing access to superficial muscles only and measurement of compound interference. The laboratory for invasive myoelectric control focuses on investigating the use of invasive recordings (mostly intramuscular electromyography, EMG) as a means to provide independent and reliable control sources for control purposes. Intramuscular recordings may assist in overcoming the limitations of non-invasive myoelectric prostheses. These include reducing cross talk and permitting access to deep muscles. Another advantage of intramuscular recordings resides in the possibility of implanting the electrodes, such that the user avoids donning and doffing the electrodes each time the prosthesis is mounted. The work of this laboratory has gone from intramuscular feature investigation to movement classification and force estimation that may provide amputees with intuitive and proportional control. The research focuses more on the acute usability of intramuscular EMG, a way to assess its performance compared to surface EMG. Further perspectives of this laboratory include chronic usability of intramuscular EMG, Osseo-integration of intramuscular electrodes to provide a stable interface for users, the design of implantable intramuscular sensors and clinical trials.
Recording setup with intramuscular wire electrodes (left image). Force and Motor unit (MU) discharge relation during grasping in increasing force (right image).
- Surface and Intramuscular amplifiers
- Force transducers (grasping and wrist movements)
- Artificial hand
- Near infrared spectroscopy (Up to 24 channels relative changes and one channel tissue saturation index)
- Digital signal processor (DSP)
- Electrical stimulator
With permission from Jakob Lund Dideriksen
Fredrik Bajers vej 7D, 3-107