The basic Health Monitoring system of the human includes Pulse, Temperature, Humidity, Height, weight etc. Nowadays, this can be easily measured using Electronic Equipment with the help of necessary sensors. Here we are going to measure height, weight and pulse. The Pulse measurement by Pulse Oximeter which also measures the heartbeat. This is a simple and sturdy low-cost IC for measurement of both the pulse and heartbeat of the human. The height measurement with the help of the Ultrasonic sensor. The weight measurement using a load cell. These data collected with the help of Arduino and then certain actions took.
Working of the Module:
The module contains three sensors namely Ultrasonic for Height; Pulse for Pulse Oximeter and Load cell for Weight measurement. First, we shall see the basic working principle of each sensor.
The Ultrasonic sensor is a transducer used to measure the height, distance and sense the proximity. This acts as a Transmitter and Receiver. Ultrasonic sound oscillates at a frequency above the human hearing range. The trigger signal from the Arduino and then it transmits the ultrasonic waves. If there is an obstacle in the path of transmission of the signal, the wave hits the object and reflects back to the sensor. The reflected wave received at the Receiver. From the time travelled, the distance of the object calculated
We know Speed is the product of Distance and Time. From this basic formulae, you can find the Distance or Level of an Object easily.
The Pulse Oximeter measures both Pulse and Heartbeat of the human. The sensor contains two LED and Photodetector. The pulse measurement placing the finger inside the sensor. The two led used are Red and IR led. They both emit different wavelengths. This is supported optical power variation because the light scattered or absorbed during its path through the blood flow because the heartbeat varies. When putting down to the blood in any part of the body, the light gets either absorb or scatter. This light seeks by the photodetector.
The Load cell used for weight measurement. This works on the principle of Wheat-stone bridge concept. The changes in resistance proportional to force applied, bridge imbalance is measured using electronic equipment. The output is in the range of Milli-Volts which requires amplification for further usage. Typically, high-resolution ADC, usually 24 bit used directly. Load cells are Quarter bridge or half bridge obtainable. The amplified output sent to Arduino
For more details about the sensor, visit the below links.
Load cell Tutorial: