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A Novel Percutaneous Electrode Implant for Improving Robustness in Advanced Myoelectric Control.

Hahne JM, Farina D, Jiang N, Liebetanz D - Front Neurosci (2016)

Bottom Line: Moreover, being percutaneous, it does not require power and data telemetry modules.The implants showed significantly lower impedance and greater robustness against mechanical interference than traditional surface EMG electrodes used for myoelectric control.Moreover, the EMG signals detected by the proposed systems allowed more stable control performance across sessions in different days than that achieved with classic EMG electrodes.

View Article: PubMed Central - PubMed

Affiliation: Institute of Neurorehabilitation Systems, University Medical Center Göttingen Göttingen, Germany.

ABSTRACT
Despite several decades of research, electrically powered hand and arm prostheses are still controlled with very simple algorithms that process the surface electromyogram (EMG) of remnant muscles to achieve control of one prosthetic function at a time. More advanced machine learning methods have shown promising results under laboratory conditions. However, limited robustness has largely prevented the transfer of these laboratory advances to clinical applications. In this paper, we introduce a novel percutaneous EMG electrode to be implanted chronically with the aim of improving the reliability of EMG detection in myoelectric control. The proposed electrode requires a minimally invasive procedure for its implantation, similar to a cosmetic micro-dermal implant. Moreover, being percutaneous, it does not require power and data telemetry modules. Four of these electrodes were chronically implanted in the forearm of an able-bodied human volunteer for testing their characteristics. The implants showed significantly lower impedance and greater robustness against mechanical interference than traditional surface EMG electrodes used for myoelectric control. Moreover, the EMG signals detected by the proposed systems allowed more stable control performance across sessions in different days than that achieved with classic EMG electrodes. In conclusion, the proposed implants may be a promising interface for clinically available prostheses.

No MeSH data available.


Related in: MedlinePlus

Robustness test against mechanical vibrations. (A) The subject is using an impact driver while signals are acquired. (B) Signals recorded during mechanically applied vibrations to the forearm. While the signals of the dry electrodes show large artifacts during the three periods in which the vibrations are applied (gray background), the signals of the gelled Ag/AgCl electrodes and the implants are almost not affected.
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Figure 7: Robustness test against mechanical vibrations. (A) The subject is using an impact driver while signals are acquired. (B) Signals recorded during mechanically applied vibrations to the forearm. While the signals of the dry electrodes show large artifacts during the three periods in which the vibrations are applied (gray background), the signals of the gelled Ag/AgCl electrodes and the implants are almost not affected.

Mentions: In the test with mechanical interference (Figure 7A), the dry electrodes showed strong artifacts during the interference periods, with a broad frequency spectrum between 0 and 100 Hz (peak below 20 Hz). Even after band-pass filtering (30–500 Hz), the amplitude of the artifacts exceeded those of the EMG signals during moderate contractions (Figure 7B). The Ag/AgCl electrodes and the implants were significantly less influenced by this type of interference. The small activity detected by those electrodes (mainly in the interval 13–20 s) is presumably caused by stabilizing muscle contractions, as an involuntary response to the mechanical interference.


A Novel Percutaneous Electrode Implant for Improving Robustness in Advanced Myoelectric Control.

Hahne JM, Farina D, Jiang N, Liebetanz D - Front Neurosci (2016)

Robustness test against mechanical vibrations. (A) The subject is using an impact driver while signals are acquired. (B) Signals recorded during mechanically applied vibrations to the forearm. While the signals of the dry electrodes show large artifacts during the three periods in which the vibrations are applied (gray background), the signals of the gelled Ag/AgCl electrodes and the implants are almost not affected.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4814550&req=5

Figure 7: Robustness test against mechanical vibrations. (A) The subject is using an impact driver while signals are acquired. (B) Signals recorded during mechanically applied vibrations to the forearm. While the signals of the dry electrodes show large artifacts during the three periods in which the vibrations are applied (gray background), the signals of the gelled Ag/AgCl electrodes and the implants are almost not affected.
Mentions: In the test with mechanical interference (Figure 7A), the dry electrodes showed strong artifacts during the interference periods, with a broad frequency spectrum between 0 and 100 Hz (peak below 20 Hz). Even after band-pass filtering (30–500 Hz), the amplitude of the artifacts exceeded those of the EMG signals during moderate contractions (Figure 7B). The Ag/AgCl electrodes and the implants were significantly less influenced by this type of interference. The small activity detected by those electrodes (mainly in the interval 13–20 s) is presumably caused by stabilizing muscle contractions, as an involuntary response to the mechanical interference.

Bottom Line: Moreover, being percutaneous, it does not require power and data telemetry modules.The implants showed significantly lower impedance and greater robustness against mechanical interference than traditional surface EMG electrodes used for myoelectric control.Moreover, the EMG signals detected by the proposed systems allowed more stable control performance across sessions in different days than that achieved with classic EMG electrodes.

View Article: PubMed Central - PubMed

Affiliation: Institute of Neurorehabilitation Systems, University Medical Center Göttingen Göttingen, Germany.

ABSTRACT
Despite several decades of research, electrically powered hand and arm prostheses are still controlled with very simple algorithms that process the surface electromyogram (EMG) of remnant muscles to achieve control of one prosthetic function at a time. More advanced machine learning methods have shown promising results under laboratory conditions. However, limited robustness has largely prevented the transfer of these laboratory advances to clinical applications. In this paper, we introduce a novel percutaneous EMG electrode to be implanted chronically with the aim of improving the reliability of EMG detection in myoelectric control. The proposed electrode requires a minimally invasive procedure for its implantation, similar to a cosmetic micro-dermal implant. Moreover, being percutaneous, it does not require power and data telemetry modules. Four of these electrodes were chronically implanted in the forearm of an able-bodied human volunteer for testing their characteristics. The implants showed significantly lower impedance and greater robustness against mechanical interference than traditional surface EMG electrodes used for myoelectric control. Moreover, the EMG signals detected by the proposed systems allowed more stable control performance across sessions in different days than that achieved with classic EMG electrodes. In conclusion, the proposed implants may be a promising interface for clinically available prostheses.

No MeSH data available.


Related in: MedlinePlus