i want program for herat beat rate monitoring system using atmega 16.. plz mail the prgram on my email id:- vatsa.shankli07[at]gmail.com

This article is about a simple heart rate monitor using 8051 microcontroller. Like previous 8051 projects, AT89S51 is the microcontroller used here. The device detects the heart rate from the tip of the finger using the IR reflection method and displays it in a three segment seven segment display in beats per minute. The circuit has an accuracy of 4 strokes per minute and is very easy to use. In medical terms, the technique used here to detect heart rate is called photoplethysmography.

Photoplethysmography

Photoplethysmography is the process of optically estimating the volumetric measurement of an organ. Pulse oximetry, cardiovascular monitoring, breath detection, heart rate monitoring, etc. are few common applications of photoplethysmography. Let's take a look at the application of photoplethysmography in monitoring heart rate from tip figer. When the heart expands (diastole) the volume of blood inside the tip of the finger increases and when the heart contracts (systole) the volume of blood within the tip of the finger decreases. The resulting pulsation of the blood volume inside the finger tip is directly proportional to the heart rate and if one could count how the number of pulses in a minute, which is the heart rate in beats per minute (bpm). For this, a pair of infrared transmitter / receiver is placed in close contact with the tip of the finger. When the heart beats, the volume of blood cells under the sensor increases and this reflects more IR waves to the sensor and when there is no rhythm the reflected beam intensity decreases. The pulsating reflection is converted into a suitable current or voltage pulse by the sensor. The output of the sensor is processed by suitable electronic circuits to obtain a visible indication (digital or graphic display).

Heart rate monitor with 8051

Circuit diagram