Just place your finger on the camera lenses to measure your heart beat signal. The system requires around 10 to 20 seconds to stabilise the readings and adjust the filters. Please make sure you are in a comfortable resting position. Any movement can influence the signal readings. You will see two plots, the bottom one shows the measured signal directly, and the top one shows the Fourier Transform of the signal. The performance depends upon the camera and lightning quality, adequate pressure applied and unnecessary movement.
Medical Disclaimer
Heart Beat FFT does not provide any medical advice, and the information it contains should not be so construed or used for such purposes. The application should not replace the services of a licensed health professional or to be a substitute for the medical advice of a health professional licensed in your country. You should not rely on any information provided by the application, and you should consult a health professional licensed in your state in all matters relating to your health.