A low-cost microcontroller-based wireless ECG-blood pressure telemonitor for home care

Homecare is the provision of health care services to patients in their own home. One of the main purposes of homecare telemedicine is to develop a wireless, low-cost and use-friendly system which allows patients to measure their own vital signs, such as blood pressure and electrocardiogram (ECG), and provide the health care professionals with the facility to remotely monitor the patient´s vital signs quickly and easily. There were four major parts in developing the ECG-blood pressure homecare telemonitoring system. The first part involved the selection or designing of devices that measure the vital signs. An Omoron HEM-609 blood pressure monitor was used to acquire the patient´s blood pressure. Since ECG machines or bedside monitors are expensive to use for this purpose, an ECG amplifier was custom designed and implemented using AD624AD to amplify the ECG signal. A PIC 16C774A microcontroller was then interfaced to the wearable blood pressure monitor and the ECG amplifier to collect the data from these devices, process them, store them and feed them to a transmitter. A high performance RF Module TXM-900-HP-II transmitter and receiver were then used to wirelessly transmit and receive the vital sign data from the microcontroller to a personal computer at the receiving site. An option was then built into the system to provide the facility to transmit the signals via internet. The final part involved development of a user-friendly graphical user interface using Visual Basic to receive the incoming patient data from the receiver, store them, process them and present them in a clinically meaningful fashion to the health care professionals.