ECG Abnormalities Detection Using Doppler Shift Method

A simple heart rate monitoring system causing minimal constraints to a patient is developed. This system enables doctors to monitor the patient heart rate as well as the ECG wave form from the central monitoring system. The ultrasonic transmitter and receiver are used for ECG wave form detection from patient´s body. Using Doppler frequency shift principle the required information is obtained. The collected data will be transmitted to a central monitoring place through an FM transmitter. The received data using FM receiver is amplified, filtered and connected to a PC and speaker. The ECG waveform and the number of beats per min are displayed on the monitor and the sound of heart beat can be heard through speaker. Whenever patient´s heart rate is abnormal a red colored display (DANGER) will appear on the monitor. The Low power transmitter is designed to modulate the transmitting signal with a carrier frequency of 100 MHz. The carrier frequency can be adjusted to desired frequency to avoid the interference of local FM radio signals. A gain adjustable potentiometer is incorporated at the receiving end to adjust the amplitude of the received QRS complex wave form for the magnified image. The software written in ´C´ language is used in order to display the heart rate and the ECG waveform on the computer screen. The system is tested by placing the transmitter and receiver by 50 ft apart and observed the ECG wave form and heart rate.