ECG Pulse Sensor module

About me:

Hi, I’m an electrical engineering student at the University of California. Currently, I’m working on projects relating to health monitoring wearable devices. My research area is about developing non-invasive biosensors such as glucose sensor and heart pulse sensor.

Objective:

This project is to make a sensor that detects heart-rate using reflective optical sensor based on photo-plethysmography(PPG) which is a technique that measures the variation of light passing through human tissues.

About the project:

The ECG Pulse Sensor module is a cost-minimized heart pulse sensor module that precisely detects the heart pulse and processes signal to the digital output which can be interfaced with microcontrollers or other digital devices.

This module is made to use with either CNY 70 or VCNT 2020 which are reflective optical sensors with infrared light emitter and phototransistor.

Placing a finger on the sensor, the variation of light will be detected by a phototransistor. The raw signal detected consists of DC and AC parts caused by the reflection of light on the finger tissue and the pulsatile blood respectively. The signal will be processed by a high pass filter allowing only AC part which we are interested to pass. Then, the noise including 50Hz AC will be filtered out by a low pass filter. At the end, a comparator op-amp will convert the PPG signal to TTL pulses (digital signal) which are synchronous with the heartbeat.    

Features:

·       Measure heart rate from your fingertip

·       Use photoplethysmography (PPG) technique

·       Operate at 3 - 5.5V range

·       Compatible with almost all micro-controller including Arduino

·       Digital pulse output

·       Built-in LED indicating heart pulse

·       CNY70 or VCNT2020 Reflective Optical Sensor

Application:

Heart-rate monitoring device

The output signal can be easily read by Arduino.

### Words to PCBWay

Recently, I have been ordering PCBs from PCBWay for all my projects. Projects relating to wearable devices usually deal with SMD parts which require very precise PCB 

manufacturing. PCBWay provides professional PCBs quality with affordable price.

Component: See BOM 

INSTRUCTIONS

Power with 2 - 5.5V supply

Connect Vout pin to Analog or Digital i/o pin of a microcontroller.