High sensitive measurement of ECG and EMG signals

HIGH SENSITIVE MEASUREMENT OF ECG AND EMG SIGNALS (M.Sc. Thesis) Metin YILDIZ GAZİ UNIVERSITY INSTITUTE OF SCIENCE AND TECHNOLOGY July 2000 ABSTRACT In this thesis, a device has been developed for measuring ECG and EMG signals that were sensed by surface electrodes. A signal seperative circuit has also been designed for selecting various ECG derivations and EMG signals. One of the selected designed signal is than transferred to the input of the enstrumantation amplifier. The gain of this amplifier can be set to two different values by a switch for ECG and EMG signals. In order to minimize the risk of electrical shock, the signals are coupled to the monitoring device by an optical isolator. In this way an isolation of 7500 Volts is provided. After that, the ECG and EMG signals are passed through special filters and are set to suitable levels for monitoring. Also, a notch filter is used for 50 Hertz noise. Finally, electrical safety tests for the device has been made and the results has been found to be within the suitable limits of the standarts. Science Code : 646.04.01 Key Words : ECG, EKG, EMG Page Number : 145 Advisor : Doç.Dr.F.Nihal GÜLER