A Polyimide Film and Textile Insulated Capacitive Electromyography Sensor for Extramural Monitoring of Muscle 

Author: Ng Charn Loong & Mamun Bin Ibne Reaz
Publisher : UKM Press
ISBN:  9789672512271
Page: 162 m/s
Year: 2021
Price: RM30

Recent technological developments in amplifier electronics allow the use of small capacitive EMG (CEMG) biosensors. These electrodes can measure the EMG signals without galvanic contact with the human body which overcome the limitations of the contact electrode. Since no direct permanent skin contact is required, capacitive electrodes are particularly suitable for integration in ambulatory measurement systems. A detail hardware review and circuit design of a CEMG biosensor are presented.

An electrical model of skin-electrode interface was derived to determine the optimum skin-electrode capacitance of a CEMG biosensor. The cEMG biosensor is designed to be able to insulate by polyimide film and different types of textile material. All the main components of the system were fabricated and validated with a series of experiments. Experimental results showed that the CEMG biosensor insulated by polyimide film could measure EMG signal accurately and achieved extremely low noise floor of less than 2 mV.

The EMG signals measured by the conventional wet contact electrodes and the CEMG biosensor were highly correlated with the correlation coefficient value of 0.86 to 0.90 without requiring any post signal processing. Textile insulated CEMG biosensor is also able to measure EMG signal consistently. This research outcome will open up a passage to the biomedical researchers and biosensor engineers to develop an advanced and reliable ambulatory biomedical sensor to address the needs in the public healthcare sector.