ACCURACY INCREASE OF SOFTWARE AND HARDWARE APPLIANCE FOR MUSCLE ACTIVITY MEASURING AND MONITORING BY FILTRATION OF CARRIER COMPONENT AND FREQUENCIES HIGHER THAN MEASURED SIGNAL RANGE

Subject of Research. The paper proposes a method of muscle activity filtering measurements for a mobile hardwaresoftware appliance used in surface electromyography. The method extends the dynamic range of measurements by capacity growth of analog-to-digital converter aimed at the increase of recognition accuracy and range of muscle activity. Method. A filter model for signals from sensors for a muscle activity controller was developed in the Proteus Design Suite software package. The filter of the signal carrier component based on the RC high-pass filter provides isolation of the measuring unit from the reference voltage of the sensor. An active low-pass filter amplifies the signal from the sensor and filters out the noise higher than the frequency range of muscle activity signals. Main Results. Filtering of the signal carrier component and increasing the order of low-pass filter show positive results in simulation. The paper presents amplitude-frequency characteristics plots and model structures with and without RC filter, with an active low-pass filter of the first order and an active low-pass filter of the second order. An amplifier unit electrical circuit for a muscle activity controller is developed based on the methodology for muscle activity measurement filtering. The results obtained are applicable for improvement of the prototype for the mobile hardware-software appliance used in surface electromyography. Practical Relevance. The developed complex can be applied in a system for muscle activity measuring and monitoring as the rehabilitation process maintenance during the movement of patients with injuries and disorders of the musculoskeletal system. This complex can be used in various neurophysiological studies where the monitoring of muscle activity dynamics in the process of the examined subject movement is required.