“Heart Beat Sensor” sounds very complicated to be made.But it’s not the reality, it is the simplest medical device to make at home using very few components.
Heart Beat Sensor
Components required to make a Heart Beat Sensor are:-
LM 358 IC
4.7uF and 100nF Capacitors
47k,6.8k,680k, and 1k resistors.
First, let us discuss the connection of the circuit.
First, we need to connect the proximity sensor with the transmitter in forward bias and receiver in reverse biased.
After that fed the signal from the receiver to High Pass Filter.
Than amplify this signal by feeding the signal into Non-Inverting Amplifier.
The output of the amplifier will be pulsing proportional to a heart beat.
If we want to feed the signal into a controller, then we will require an additional buffer amplifier.
Now, discussing some theory of this circuit. The logic behind this is that when our heart beats, the blood circulates in our body. Due to this, there is minute volume change of blood on our index finger. Hence when we place our finger on the proximity sensor, that sensor senses that volume change and gives signal accordingly.
But this signal is very weak to even drive an LED. Hence we connect an Amplifier to amplify this signal. On the output of the amplifier, we will get the pulses which will be proportional to the Heart Beat. Our Heart Beats will be indicated by the LED connected to the output.
Further, if we want to feed this signal into the microcontroller, we need to attach an additional buffer to this circuit. In the microcontroller, we can code that controller so that we get the exact value of our Heart Beat.
So this is all about making your own Heart Beat Sensor. You can even watch my tutorial video on this in which I have made this sensor using SMD components. The link to the video is mentioned below.
Make a one for yourself and if you like this project than share it with others.