模块有两个发光二极管,一个光检测器,优化光学和低噪声的仿真信号处理,以检测脉搏血氧饱和度和心脏速率信号。
- 只需要将手指头紧贴在传感器上,就能估计 脉搏血氧饱和度(SpO2)及脉搏(相当于心跳)。
- 携带氧气的红血球能吸收较多红外光(850-1000nm),未携带氧气的红血球则是吸收较多的红光(600-750nm)。
- 因此pulse oximeter就是一个迷你的分光计,利用不同红血球之吸收光谱的原理,来分析血氧饱和度。
/* 1、安装库:IDE-工具-管理库-搜索“MAX30105”-安装 2、项目:串口读取测量数据 3、连线(I2C): VIN → 3.3V GND → GND SDA 接 A4 SCL 接 A5 */ #include <Wire.h> #include "MAX30105.h" #include "heartRate.h" MAX30105 particleSensor; const byte RATE_SIZE = 4; //Increase this for more averaging. 4 is good. byte rates[RATE_SIZE]; //Array of heart rates byte rateSpot = 0; long lastBeat = 0; //Time at which the last beat occurred float beatsPerMinute; int beatAvg; void setup() { Serial.begin(115200); Serial.println("Initializing..."); // Initialize sensor if (!particleSensor.begin(Wire, I2C_SPEED_FAST)) //Use default I2C port, 400kHz speed { Serial.println("MAX30105 was not found. Please check wiring/power. "); while (1); } Serial.println("Place your index finger on the sensor with steady pressure."); particleSensor.setup(); //Configure sensor with default settings particleSensor.setPulseAmplitudeRed(0x0A); //Turn Red LED to low to indicate sensor is running particleSensor.setPulseAmplitudeGreen(0); //Turn off Green LED } void loop() { long irValue = particleSensor.getIR(); if (checkForBeat(irValue) == true) { //We sensed a beat! long delta = millis() - lastBeat; lastBeat = millis(); beatsPerMinute = 60 / (delta / 1000.0); if (beatsPerMinute < 255 && beatsPerMinute > 20) { rates[rateSpot++] = (byte)beatsPerMinute; //Store this reading in the array rateSpot %= RATE_SIZE; //Wrap variable //Take average of readings beatAvg = 0; for (byte x = 0 ; x < RATE_SIZE ; x++) beatAvg += rates[x]; beatAvg /= RATE_SIZE; } } Serial.print("IR="); Serial.print(irValue); Serial.print(", BPM="); Serial.print(beatsPerMinute); Serial.print(", Avg BPM="); Serial.print(beatAvg); Serial.println(); delay(1000); }