IoT-Based Remote Patient Monitoring System to Measure Vital

1#include <Wire.h>
2#include "MAX30100_PulseOximeter.h"
3#include "MAX30100.h"
4#include <Adafruit_MLX90614.h>
5#include <Adafruit_GFX.h>
6#include <U8x8lib.h>
7#include <avr/dtostrf.h>
8#define REPORTING_PERIOD_MS     500   //update rate of hr, spo2, ambient, object, hrv, etc parameters in milli seconds 
9#define DISPLAY_INTERVAL        5     //update rate for the i2c display = REPORTING_PERIOD_MS*DISPLAY_INTERVAL
10#define COMPENSATION            5     //compensation in object temperature. Different body parts have different temperatures. Fingers are around 5 degF lower than core body temperature
11// objects
12PulseOximeter pox;    //this offers spo2 and hr calculation 
13Adafruit_MLX90614 mlx = Adafruit_MLX90614();
14U8X8_SH1106_128X64_NONAME_HW_I2C u8x8(/* reset=*/ U8X8_PIN_NONE);
15MAX30100 sensor;
16//variables
17uint32_t tsLastReport = 0;
18int hr, spo2, count = 0, flag = 0, PatientID = 0;
19float ambient, object, hrv;
20long time1 = 0, time2 = 0; 
21uint16_t ir = 0, red = 0, ecg = 0, mic; ;
22char str_hrv[10], str_object[10], str_ambient[10], str_ir[10], str_red[10];
23// Callback (registered below) fired when a pulse is detected
24void onBeatDetected()
25{
26    time1 = micros() - time2;
27    time2 = micros();
28}
29void setup()
30{
31    //display connected
32    u8x8.begin();
33    u8x8.setPowerSave(0);
34    u8x8.setFont(u8x8_font_chroma48medium8_r);
35    //pinMode(10, INPUT); // Setup for leads off detection LO +
36    //pinMode(11, INPUT); // Setup for leads off detection LO -
37    Serial.begin(115200);
38    /*
39    while (!Serial) {
40      ; // wait for serial port to connect. Needed for native USB port only
41    }
42    */
43    // Initialize the PulseOximeter instance
44    // Failures are generally due to an improper I2C wiring, missing power supply
45    // or wrong target chip
46    if (!pox.begin(PULSEOXIMETER_DEBUGGINGMODE_RAW_VALUES)) {
47        //Serial.println("FAILED");
48        for(;;);
49    } else {
50        //Serial.println("SUCCESS");
51    }
52    // The default current for the IR LED is 50mA and it could be changed
53    //   by uncommenting the following line. Check MAX30100_Registers.h for all the
54    //   available options.
55    pox.setIRLedCurrent(MAX30100_LED_CURR_11MA);
56    // Register a callback for the beat detection
57    pox.setOnBeatDetectedCallback(onBeatDetected);
58    mlx.begin();
59    time2 = micros();
60}
61void loop()
62{
63    // Make sure to call update as fast as possible
64    pox.update();
65    sensor.update();
66    //reading continuous functions (signals) every loop
67    while (sensor.getRawValues(&ir, &red)) {}
68    ecg = analogRead(A0);
69    ecg = map(ecg, 250, 500, 0, 100);
70    mic = analogRead(A1);
71    delay(1);
72    // Asynchronously calculate other variables every REPORTING_PERIOD_MS
73    // For hr and spo2, a value of 0 means "invalid", for object and ambient temperatures a value less than 70 degF or higher than 110 degF can be considered abnormal
74    if (millis() - tsLastReport > REPORTING_PERIOD_MS) {
75        hr = pox.getHeartRate();
76        spo2 = pox.getSpO2();
77        ambient = mlx.readAmbientTempF();
78        object = mlx.readObjectTempF() + COMPENSATION;
79        hrv = (60000000/hr - (float)time1)/1000;
80        //send_serial();
81        tsLastReport = millis();
82        count++;
83        flag = 0;
84    }
85    //Display all variables on the display after DISPLAY_INTERVAL seconds
86    if ((count%DISPLAY_INTERVAL == 0) && (flag != 1)) {
87      flag = 1;   //This flag makes sure the display is updated only once every DISPLAY_INTERVAL seconds
88      Wire.end();
89      send_display();
90      Wire.begin();     
91    }
92    Telemetry();
93}
94//serial monitor print function. 
95//Not required actually as telemetry function prints all values in csv format on the serial monitor
96void send_serial() {
97  Serial.print("bpm / SpO2:");
98  Serial.print("Heart rate:");
99  Serial.print(hr);
100  Serial.print(spo2);
101  Serial.print("% / hrv:");
102  Serial.print(hrv);
103  Serial.print("ms / Ambient:");
104  Serial.print(ambient); 
105  Serial.print("*F / tObject = "); 
106  Serial.print(object); 
107  Serial.println("*F");
108}
109//display print function
110void send_display() {
111  u8x8.clearDisplay();
112  u8x8.setCursor(0,1);
113  u8x8.print("HRV:"); 
114  u8x8.print(hrv);
115  u8x8.print(" ms");
116  u8x8.setCursor(0,2);
117  u8x8.print("SpO2:");
118  u8x8.print(spo2);
119  u8x8.print(" %");
120  u8x8.setCursor(0,3);
121  u8x8.print("HR:");
122  u8x8.print(hr);
123  u8x8.print(" bpm");
124  u8x8.setCursor(0,4);
125  u8x8.print("Temp:");
126  u8x8.print(object);
127  u8x8.print(" degF");
128  u8x8.setCursor(0,5);
129  u8x8.print("ecg:");
130  u8x8.print(ecg);
131  u8x8.setCursor(0,6);
132  u8x8.print("mic");
133  u8x8.print(mic);
134  //delay(200); 
135}
136//serial telemetry for edge impulse data forwarder
137void Telemetry() {
138  char buffer[150];
139  dtostrf(hrv, 4, 2, str_hrv);
140  dtostrf(object, 4, 2, str_object);
141  dtostrf(ambient, 4, 2, str_ambient);
142  dtostrf((float)ir/100, 5, 2, str_ir);
143  dtostrf((float)red/100, 5, 2, str_red);
144  sprintf(buffer,"%d,%d,%d,%d,%s,%s,%s,%s,%s,%d,%d",PatientID,count/10,hr,spo2,str_hrv,str_object,str_ambient,str_ir,str_red,ecg,mic);
145  Serial.println(buffer);