[chip scheme design] pulse oximeter

　　 The scheme of using oximeter chip MCU The main control chip is combined with a red light sensor , To reduce hemoglobin （Hb）、 Oxygenated hemoglobin （HbO2） The absorption spectrum characteristics in the red and near-infrared regions are the theoretical basis , Blood oxygen content and heart rate measurement , And display the measured results on the display . The accuracy of blood oxygen content can reach ±1%, The accuracy of heart rate can reach ±1bpm or ±1 Take a big value . When measuring, just insert your finger , The display screen will directly display the measured oxygen saturation value , It has high accuracy and repeatability .

　　 Introduction to the main components and principles of the oximeter ：

　　MCU

　　 Memory (EPROM And RAM）

　　 Two controls LED Digital to analog converter

　　 A device that filters and amplifies the signal received by the photodiode

　　 The analog-to-digital converter that digitizes the received signal to provide it to the microprocessor

　　 Small LCD

　　 Finger clip oximeter chip program specifications

　　◆ Display type :OLED Blue and yellow dual color display

　　◆ Blood oxygen saturation

　　 measuring range :70%~100%

　　 precision : Scholar 1%

　　◆ heart rate

　　 measuring range :25BPM~250BPM

　　 precision : Scholar 1BPM

　　◆ Blood perfusion index :≥0.3%, Scholar 0.1%

　　◆ Display type :OLED display

　　◆ Manually adjust the interface direction :6 Display mode ,4 Two display directions

　　◆LED Show : Display both test values and bar graphs

　　◆ Low battery voltage indicator

　　◆ Automatic standby or sleep ( The automatic sleep time is about 12 second )

　　◆ Blood oxygen saturation

　　◆ Call the police

　　 Basic parameter alarm : Low saturation alarm , high ( low ) Pulse rate alarm

　　 Sensor status alarm : The sensor automatically falls off and gives an alarm

　　 System fault alarm : Falling off alarm , Low battery alarm : The voltage is below 2.4V( It can be modified according to the actual product situation )