Wireless Transmission of Real Time Electrocardiogram (ECG) Signals through Radio Frequency (RF) Waves

In this project the Electrocardiogram (ECG) is recorded with the help of three ECG electrodes and after amplification and frequency modulation it is transmitted as FM signal. By changing the position of ECG electrodes on the body the ECG signal of lead I, lead II and lead III are recorded. Instrumentation amplifier INA 114 is used to collect the ECG signal from the body which gives excellent accuracy. This also provides the gain of around 11. The amplifier section is used to amplify the signal so that it can be transmitted. The amplifier circuit is built around IC LM358. Total gain of around 1000 is achieved. This amplified signal is given to FM transmitter where it is frequency modulated and transmitted. The range of transmission is around 300 meters which is sufficient for the hospital applications. In this project we used the radio receiver CXA1619/BS which receives ECG signals and after demodulation converts back into voltage form. We can adjust the frequency with the help of a tuner which is available on the receiver unit. An RC low pass filter is used to remove the unwanted noise. The output is displayed on a simple oscilloscope. Thus ECG signals can be transmitted without any direct connection of wires between ECG data acquisition part and display monitor.