The Future of Oximetry Monitoring: Integration of PPG Technology and Hardware Design in Wearable Devices

Photo Photo Plethyamo Graphy (PPG) technology is a non-invasive optical method for measuring changes in blood flow. The basic principle is based on the absorption and reflection of light: a specific wavelength of red or infrared light is emitted at the surface of the skin and, using the automatic absorption and reflection properties of the body's tissues, the optical signals generated by the attenuation of the reflectivity of the light intensity are passed through a sensor to generate an electrical signal. Due to the variability of haemoglobin types in the blood, different haemoglobins have specific absorption properties for different wavelengths of light. Therefore, PPG technology can assess blood flow status and blood oxygen levels by analysing light reflectance. In recent years, with the changes in science and technology and the increasing health consciousness of all people, the market demand for wearable oximetry wristbands has increased significantly. Various brands and models with different functions and price positioning have appeared in the market. In this thesis, research based on PPG technology is conducted and the optimisation of the hardware design of wearable oximeters is discussed. It is found in this thesis that the working performance of portable oximeters can be greatly improved after a series of hardware optimisation designs.