Miniaturized Pulse Oximeter
Created: Feb 08, 2016
No description available.
Electronic equipments for medical purposes plays a big role in saving lives everyday. It needs to be accurate in data and precise in each reading. In this reference design is a miniaturized pulse oximeter, a device that measures the changes in oxygen level in the human blood through light reflection. The reference design uses AFE4403 as the main component which is a fully-integrated analog front end that consist of a LED transmit section for the photodiode sensor. A low noise channel receiver with an ADC converter is also integrated for fast conversion of analog data. An external crystal oscillator is being used in this reference design to provide a low-jitter clock to the AFE4403. The design also consists of MSP430F5528IYFF a mixed-signal microcontroller that contains the data and holds the algorithm of each measurements.
The operation of this reference design starts when the DCM03 an integrated dual emitter and photodetector, emits the light to the part of the body where the oxygen level measurement will be taken. The oxygen saturation or refers to the amount of oxygenated haemoglobin in the blood (SpO2) is being measured through the amount of reflected light from the tissue. The output of the DCM03 then being measured by AFE4403 and log to the microcontroller MSP430F5528IYFFR which process the calculation for the end result. SPI interface is the means of communication of AFE4403 to an external microcontroller and it has configurable timing controller that allow the user to have the full control of its timing characteristics. The AFE4403 comes also with a fault diagnostics using a photodiode and LED open and short.
The reference design can be enhance and incorporate with some other application such as smart watch, finger pulse oximeter and other applications that needs measurement of oxygenated blood in the body. Other applications of AFE4403 may found also in optical HRM and industrial photometry.