In this project, we will make an IoT Healthcare kit which records the patient heart beat rate and body temperature and also send an email/SMS alert whenever those readings goes beyond critical values. Pulse rate and body temperature readings are recorded over ThingSpeak and Google sheets so that patient health can be monitored from anywhere in the world over internet. A panic will also be attached so that patient can press it on emergency to send email/sms to their relatives.

Required Components:

1. Arduino Uno
2. ESP8266 Wi-Fi module
3. LM35 temperature sensor
4. Pulse rate sensor
5. Push button
6. 10k Resistor
7. Jumper wires

Code:

#define USE_ARDUINO_INTERRUPTS true    
#define DEBUG true
#define SSID "********"     // "SSID-WiFiname"
#define PASS "************" // "password"
#define IP "184.106.153.149"      // thingspeak.com ip

#include <SoftwareSerial.h>
#include "Timer.h"
#include <PulseSensorPlayground.h>     // Includes the PulseSensorPlayground Library.   
Timer t;
PulseSensorPlayground pulseSensor;

String msg = "GET /update?key=your api key"; 
SoftwareSerial esp8266(10,11);

//Variables
const int PulseWire = A0;       // PulseSensor PURPLE WIRE connected to ANALOG PIN 0
const int LED13 = 13;          // The on-board Arduino LED, close to PIN 13.
int Threshold = 550;           //for heart rate sensor
float myTemp;
int myBPM;
String BPM;
String temp;
int error;
int panic;
int raw_myTemp;
float Voltage;
float tempC;
void setup()
{

  Serial.begin(9600); 
  esp8266.begin(115200);
  pulseSensor.analogInput(PulseWire);   
  pulseSensor.blinkOnPulse(LED13);       //auto-magically blink Arduino's LED with heartbeat.
  pulseSensor.setThreshold(Threshold);

// Double-check the "pulseSensor" object was created and "began" seeing a signal. 
   if (pulseSensor.begin()) {
    Serial.println("We created a pulseSensor Object !");  //This prints one time at Arduino power-up,  or on Arduino reset.  
  }
  Serial.println("AT");
  esp8266.println("AT");

delay(3000);

if(esp8266.find("OK"))
  {
    connectWiFi();
  }
  t.every(10000, getReadings);
   t.every(10000, updateInfo);
}

void loop()
{
  panic_button();
start: //label
    error=0;
   t.update();
    //Resend if transmission is not completed
    if (error==1)
    {
      goto start; //go to label "start"
    } 
 delay(4000);
}

void updateInfo()
{
  String cmd = "AT+CIPSTART=\"TCP\",\"";
  cmd += IP;
  cmd += "\",80";
  Serial.println(cmd);
  esp8266.println(cmd);
  delay(2000);
  if(esp8266.find("Error"))
  {
    return;
  }
  cmd = msg ;
  cmd += "&field1=";    //field 1 for BPM
  cmd += BPM;
  cmd += "&field2=";  //field 2 for temperature
  cmd += temp;
  cmd += "\r\n";
  Serial.print("AT+CIPSEND=");
  esp8266.print("AT+CIPSEND=");
  Serial.println(cmd.length());
  esp8266.println(cmd.length());
  if(esp8266.find(">"))
  {
    Serial.print(cmd);
    esp8266.print(cmd);
  }
  else
  {
    Serial.println("AT+CIPCLOSE");
    esp8266.println("AT+CIPCLOSE");
    //Resend...
    error=1;
  }
}

boolean connectWiFi()
{
  Serial.println("AT+CWMODE=1");
  esp8266.println("AT+CWMODE=1");
  delay(2000);
  String cmd="AT+CWJAP=\"";
  cmd+=SSID;
  cmd+="\",\"";
  cmd+=PASS;
  cmd+="\"";
  Serial.println(cmd);
  esp8266.println(cmd);
  delay(5000);
  if(esp8266.find("OK"))
  {
    return true;
  }
  else
  {
    return false;
  }
}

void getReadings(){
  raw_myTemp = analogRead(A1);
  Voltage = (raw_myTemp / 1023.0) * 5000; // 5000 to get millivots.
  tempC = Voltage * 0.1; 
  myTemp = (tempC * 1.8) + 32; // conver to F
  Serial.println(myTemp);
  int myBPM = pulseSensor.getBeatsPerMinute();  // Calls function on our pulseSensor object that returns BPM as an "int".
                                               // "myBPM" hold this BPM value now. 
if (pulseSensor.sawStartOfBeat()) {            // Constantly test to see if "a beat happened". 
Serial.println(myBPM);                        // Print the value inside of myBPM. 
}

delay(20);            
    char buffer1[10];
     char buffer2[10];
    BPM = dtostrf(myBPM, 4, 1, buffer1);
    temp = dtostrf(myTemp, 4, 1, buffer2);  
  }

void panic_button(){
  panic = digitalRead(8);
    if(panic == HIGH){
    Serial.println(panic);
      String cmd = "AT+CIPSTART=\"TCP\",\"";
  cmd += IP;
  cmd += "\",80";
  Serial.println(cmd);
  esp8266.println(cmd);
  delay(2000);
  if(esp8266.find("Error"))
  {
    return;
  }
  cmd = msg ;
  cmd += "&field3=";    
  cmd += panic;
  cmd += "\r\n";
  Serial.print("AT+CIPSEND=");
  esp8266.print("AT+CIPSEND=");
  Serial.println(cmd.length());
  esp8266.println(cmd.length());
  if(esp8266.find(">"))
  {
    Serial.print(cmd);
    esp8266.print(cmd);
  }
  else
  {
    Serial.println("AT+CIPCLOSE");
    esp8266.println("AT+CIPCLOSE");
    //Resend...
    error=1;
  }
}
}