DESIGN AND CONSTRUCTION OF A HEART RATE MONITOR USING A LOW COST MICROCONTROLLER

Abstract

This project describes the design of a simple low cost micro controller based heart rate measuring device with LCD output. The design considerations for this project are mostly influenced by the proposed users of the system. These users are medical practitioners in developing countries, who have very limited medical infrastructure. Hence, low cost, low power, portability, and ease of use are factors that are considered at every stage of the design. This system explores the AT89C52 microcontroller which is a low-power, high-performance CMOS 8-bit microcomputer. The device is manufactured using Atmel's high density non-volatile memory technology and is compatible with the industry standard 80C51 and 80C52 instruction set and pin out. Heart rate of the subject is measured from the finger using infra-red transmitter and received sensor box and the rate is then averaged and displayed on a text based LCD. The device has the advantage that it is microcontroller based and thus can be programmed to display various quantities, such as the average, maximum and minimum rates over a period of time. Another advantage of such a design is that it can be expanded and can easily be connected to a recording device or a PC to collect and analyze the data for over a period of time. Lastly, this device can be used by non- professional people at home to measure their heart rate easily and safely.