DSP BASED WIRELESS ECG MONITORING

ECG (Electrocardiogram gram) Monitoring is a very important parameter for heart patient. It will give a complete waveform on screen for diagnosis. For a heart patient, he may have valve problem, blood vessels block, or hole in the heart. Only way to identify all the above problems is to monitor ECG parameter. Particularly for a heart patient, he must be very careful in diet, work, etc., if suppose some time he may get wrong diet or extra work, he has to check his ECG, for checking ECG he has to go to the hospital and after getting ECG signal he can have the doctor’s advice.

For a busy person it may not possible to go to the hospital for check up in time. He can monitor the ECG wave form from the home or office and he can transfer the waveform to the hospital through air, and also he can have advice from the doctor. This is the particular part which we are going to concentrate in this project. This project may not only useful to communicate between the patients to the doctor. It will be very much useful to the hospitals to get the experts advice. i.e., if a heart specialist is available in abroad suppose to say in USA. A patient is in a hospital which may locate at Chennai. By using this project we can transfer the patient’s ECG waveform through air from Chennai to USA. It will be very much useful to save a patient’s life.  

WORKING PRINCIPLE

There are many different types of ECG Electrodes are available to measure the ECG signal. We are going to design a circuit to get input from all types of sensors. There may be some noises mixed in the waveform, particularly supply noises will be there. Those noises will be eliminated with the help of filter circuits. Then the ECG signal will be amplified with the help of amplifier circuits, and then the amplified output will be given to the ADC, which is an 8-bit eight channel ADC, that will be useful to monitor multiple patients. Then the digitized data will be given to a DSP(Digital Signal Processor). That will convert the eight bit parallel data to serial format. Then the serial output will be given through the inbuilt UART available in the micro controller.

The serial output from the micro controller will be given to a modulator circuit, that modulation should be a digital modulation. Then the digitally modulated signal will be given to an AM modulation for further improvement, and then the AM modulated output will be transmitted in the air.

At the receiver end the AM demodulation can be done with the help of diode detection method, and the detected signal will be a very weak signal, that can be amplified with the help of FET. Then the amplified signal will be given to the digital demodulation. Then the demodulated signal will be in the form of TTL logic pulses (i.e., 0v and 5v). That TTL output will be converted into RS232 format (i.e.,-12v and +12v), then the pulse output will be given to the PC through Serial port (Com Port). Then the received serial input is converted in to parallel data and that will be monitored in the PC with the help of a ‘c’ program.