Health Monitoring System

Introduction

The IoT Based Patient Health Monitoring System using ESP8266 & Arduino. The IoT platform used in this project is ThingSpeak. ThingSpeak is an open-source Internet of Things (IoT) application and API to store and retrieve data from things using the HTTP protocol over the Internet or via a Local Area Network. This IoT device could read the beats rate and measure the surrounding temperatureerature. It continuously monitors the beats rate and surrounding temperatureerature and updates them to an IoT platform.

Components

Before you start building your Arduino-based drone, make sure you have the following components:

Arduino Nano Board

ESP8266-01 WiFi Module

16x2 LCD Display

Potentiometer 10K

Beats Sensor

LM35 Temperatureerature Sensor

2K Resistor

1K Resistor

LED 5mm Any Color

Connecting Wires

Breadboard

Circuit diagram

1. Connect Beats Sensor output pin to A0 of Arduino and other two pins to VCC & GND.

2. Connect LM35 Temperatureerature Sensor output pin to A1 of Arduino and other two pins to VCC & GND.

3. Connect the LED to Digital Pin 7 of Arduino via a 220-ohm resistor.

4. Connect Pin 1,3,5,16 of LCD to GND.

5. Connect Pin 2,15 of LCD to VCC.

6. Connect Pin 4,6,11,12,13,14 of LCD to Digital Pin12,11,5,4,3,2 of Arduino.

7. The RX pin of ESP8266 works on 3.3V and it will not communicate with the Arduino when we will connect it directly to the Arduino. So, we will have to make a voltage divider for it which will convert the 5V into 3.3V. This can be done by connecting the 2.2K & 1K resistor. Thus the RX pin of the ESP8266 is connected to pin 10 of Arduino through the resistors.

8. Connect the TX pin of the ESP8266 to pin 9 of the Arduino.

IoT Based Patient Health Monitoring System using ESP8266 & Arduino as shown in the figure here.

Code

#include

LiquidCrystal lcd(12, 11, 5, 4, 3, 2);

#include

float beats = 0;

float temperature = 0;

SoftwareSerial ser(9,10);

String apiKey = "OO707TGA1BLUNN12";

// Variables

int beatsPin = A0; // Beats Sensor purple wire connected to analog pin 0

int blinkPin = 7 ; // pin to blink led at each beat

int fadePin = 13; // pin to do fancy classy fading blink at each beat

int fadeRate = 0; // used to fade LED on with PWM on fadePin

// Volatile Variables, used in the interrupt service routine!

volatile int bpm; // int that holds raw Analog in 0. updated every 2mS

volatile int signal; // holds the incoming raw data

volatile int IBI = 600; // int that holds the time interval between beats! Must be seeded!

volatile boolean Beats = false; // "True" when User's live heartbeat is detected. "False" when nota "live beat".

volatile boolean QS = false; // becomes true when Arduoino finds a beat.

// Regards Serial OutPut -- Set This Up to your needs

static boolean serialVisual = true; // Set to 'false' by Default. Re-set to 'true' to see Arduino Serial Monitor ASCII Visual Beats

volatile int rate[10]; // array to hold last ten IBI values

volatile unsigned long sampleCounter = 0; // used to determine beats timing

volatile unsigned long lastBeatTime = 0; // used to find IBI

volatile int P = 512; // used to find peak in beats wave, seeded

volatile int T = 512; // used to find trough in beats wave, seeded

volatile int thresh = 525; // used to find instant moment of heart beat, seeded

volatile int amp = 100; // used to hold amplitude of beats waveform, seeded

volatile boolean firstBeat = true; // used to seed rate array so we startup with reasonable BPM

volatile boolean secondBeat = false; // used to seed rate array so we startup with reasonable BPM

void setup()

{

lcd.begin(16, 2);

pinMode(blinkPin,OUTPUT); // pin that will blink to your heartbeat!

pinMode(fadePin,OUTPUT); // pin that will fade to your heartbeat!

Serial.begin(115200); // we agree to talk fast!

interruptSetup(); // sets up to read Beats Sensor signal every 2mS

// IF YOU ARE POWERING The Beats Sensor AT VOLTAGE LESS THAN THE BOARD VOLTAGE,

// UN-COMMENT THE NEXT LINE AND APPLY THAT VOLTAGE TO THE A-REF PIN

// analogReference(EXTERNAL);

lcd.clear();

lcd.setCursor(0,0);

lcd.print(" Patient Health");

lcd.setCursor(0,1);

lcd.print(" Monitoring ");

delay(4000);

lcd.clear();

lcd.setCursor(0,0);

lcd.print("Initializing....");

delay(5000);

lcd.clear();

lcd.setCursor(0,0);

lcd.print("Getting Data....");

ser.begin(9600);

ser.println("AT");

delay(1000);

ser.println("AT+GMR");

delay(1000);

ser.println("AT+CWMODE=3");

delay(1000);

ser.println("AT+RST");

delay(5000);

ser.println("AT+CIPMUX=1");

delay(1000);

String cmd="AT+CWJAP=\"Alexahome\",\"98765432\"";

ser.println(cmd);

delay(1000);

ser.println("AT+CIFSR");

delay(1000);

}

// Where the Magic Happens

void loop()

{

serialOutput();

if (QS == true) // A Heartbeat Was Found

{

// BPM and IBI have been Determined

// Quantified Self "QS" true when arduino finds a heartbeat

fadeRate = 255; // Makes the LED Fade Effect Happen, Set 'fadeRate' Variable to 255 to fade LED with beats

serialOutputWhenBeatHappens(); // A Beat Happened, Output that to serial.

QS = false; // reset the Quantified Self flag for next time

}

ledFadeToBeat(); // Makes the LED Fade Effect Happen

delay(20); // take a break

read_temperature();

esp_8266();

}

void ledFadeToBeat()

{

fadeRate -= 15; // set LED fade value

fadeRate = constrain(fadeRate,0,255); // keep LED fade value from going into negative numbers!

analogWrite(fadePin,fadeRate); // fade LED

}

void interruptSetup()

{

// Initializes Timer2 to throw an interrupt every 2mS.

TCCR2A = 0x02; // DISABLE PWM ON DIGITAL PINS 3 AND 11, AND GO INTO CTC MODE

TCCR2B = 0x06; // DON'T FORCE COMPARE, 256 PRESCALER

OCR2A = 0X7C; // SET THE TOP OF THE COUNT TO 124 FOR 500Hz SAMPLE RATE

TIMSK2 = 0x02; // ENABLE INTERRUPT ON MATCH BETWEEN TIMER2 AND OCR2A

sei(); // MAKE SURE GLOBAL INTERRUPTS ARE ENABLED

}

void serialOutput()

{ // Decide How To Output Serial.

if (serialVisual == true)

{

arduinoSerialMonitorVisual('-', Signal); // goes to function that makes Serial Monitor Visualizer

}

else

{

sendDataToSerial('S', Signal); // goes to sendDataToSerial function

}

}

void serialOutputWhenBeatHappens()

{

if (serialVisual == true) // Code to Make the Serial Monitor Visualizer Work

{

Serial.print("*** Heart-Beat Happened *** "); //ASCII Art Madness

Serial.print("BPM: ");

Serial.println(BPM);

}

else

{

sendDataToSerial('B',BPM); // send heart rate with a 'B' prefix

sendDataToSerial('Q',IBI); // send time between beats with a 'Q' prefix

}

}

void arduinoSerialMonitorVisual(char symbol, int data )

{

const int sensorMin = 0; // sensor minimum, discovered through experiment

const int sensorMax = 1024; // sensor maximum, discovered through experiment

int sensorReading = data; // map the sensor range to a range of 12 options:

int range = map(sensorReading, sensorMin, sensorMax, 0, 11);

// do something different depending on the

// range value:

switch (range)

{

case 0:

Serial.println(""); /////ASCII Art Madness

break;

case 1:

Serial.println("---");

break;

case 2:

Serial.println("------");

break;

case 3:

Serial.println("---------");

break;

case 4:

Serial.println("------------");

break;

case 5:

Serial.println("--------------|-");

break;

case 6:

Serial.println("--------------|---");

break;

case 7:

Serial.println("--------------|-------");

break;

case 8:

Serial.println("--------------|----------");

break;

case 9:

Serial.println("--------------|----------------");

break;

case 10:

Serial.println("--------------|-------------------");

break;

case 11:

Serial.println("--------------|-----------------------");

break;

}

}

void sendDataToSerial(char symbol, int data )

{

Serial.print(symbol);

Serial.println(data);

}

ISR(TIMER2_COMPA_vect) //triggered when Timer2 counts to 124

{

cli(); // disable interrupts while we do this

signal = analogRead(beatsPin); // read the Beats Sensor

sampleCounter += 2; // keep track of the time in mS with this variable

int N = sampleCounter - lastBeatTime; // monitor the time since the last beat to avoid noise

// find the peak and trough of the beats wave

if(signal < thresh && N > (IBI/5)*3) // avoid dichrotic noise by waiting 3/5 of last IBI

{

if (signal < T) // T is the trough

{

T = signal; // keep track of lowest point in beats wave

}

}

if(signal > thresh && signal > P)

{ // thresh condition helps avoid noise

P = signal; // P is the peak

} // keep track of highest point in beats wave

// NOW IT'S TIME TO LOOK FOR THE HEART BEAT

// signal surges up in value every time there is a beats

if (N > 250)

{ // avoid high frequency noise

if ( (signal > thresh) && (Beats == false) && (N > (IBI/5)*3) )

{

Beats = true; // set the Beats flag when we think there is a beats

digitalWrite(blinkPin,HIGH); // turn on pin 13 LED

IBI = sampleCounter - lastBeatTime; // measure time between beats in mS

lastBeatTime = sampleCounter; // keep track of time for next beats

if(secondBeat)

{ // if this is the second beat, if secondBeat == TRUE

secondBeat = false; // clear secondBeat flag

for(int i=0; i<=9; i++) // seed the running total to get a realisitic BPM at startup

{

rate[i] = IBI;

}

}

if(firstBeat) // if it's the first time we found a beat, if firstBeat == TRUE

{

firstBeat = false; // clear firstBeat flag

secondBeat = true; // set the second beat flag

sei(); // enable interrupts again

return; // IBI value is unreliable so discard it

}

// keep a running total of the last 10 IBI values

word runningTotal = 0; // clear the runningTotal variable

for(int i=0; i<=8; i++)

rate[i] = rate[i+1]; // and drop the oldest IBI value

runningTotal += rate[i]; // add up the 9 oldest IBI values

}

rate[9] = IBI; // add the latest IBI to the rate array

runningTotal += rate[9]; // add the latest IBI to runningTotal

runningTotal /= 10; // average the last 10 IBI values

BPM = 60000/runningTotal; // how many beats can fit into a minute? that's BPM!

QS = true; // set Quantified Self flag

// QS FLAG IS NOT CLEARED INSIDE THIS ISR

beats = BPM;

}

}

if (Signal < thresh && Beats == true)

{ // when the values are going down, the beat is over

digitalWrite(blinkPin,LOW); // turn off pin 13 LED

Beats = false; // reset the Beats flag so we can do it again

amp = P - T; // get amplitude of the beats wave

thresh = amp/2 + T; // set thresh at 50% of the amplitude

P = thresh; // reset these for next time

T = thresh;

}

if (N > 2500)

{ // if 2.5 seconds go by without a beat

thresh = 512; // set thresh default

P = 512; // set P default

T = 512; // set T default

lastBeatTime = sampleCounter; // bring the lastBeatTime up to date

firstBeat = true; // set these to avoid noise

secondBeat = false; // when we get the heartbeat back

}

sei(); // enable interrupts when youre done!

}// end isr

void esp_8266()

{

// TCP connection AT+CIPSTART=4,"TCP","184.106.153.149",80

String cmd = "AT+CIPSTART=4,\"TCP\",\"";

cmd += "184.106.153.149"; // api.thingspeak.com

cmd += "\",80";

ser.println(cmd);

Serial.println(cmd);

if(ser.find("Error"))

{

Serial.println("AT+CIPSTART error");

return;

}

String getStr = "GET /update?api_key=";

getStr += apiKey;

getStr +="&field1=";

getStr +=String(temperature);

getStr +="&field2=";

getStr +=String(beats);

getStr += "\r\n\r\n";

// send data length

cmd = "AT+CIPSEND=4,";

cmd += String(getStr.length());

ser.println(cmd);

Serial.println(cmd);

delay(1000);

ser.print(getStr);

Serial.println(getStr); //thingspeak needs 15 sec delay between updates

delay(3000);

}

void read_temperature()

{

int temperature_val = analogRead(A1);

float mv = (temperature_val/1024.0)*5000;

float cel = mv/10;

temperature = (cel*9)/5 + 32;

Serial.print("Temperatureerature:");

Serial.println(temperature);

lcd.clear();

lcd.setCursor(0,0);

lcd.print("BPM :");

lcd.setCursor(7,0);

lcd.print(BPM);

lcd.setCursor(0,1);

lcd.print("Temperature.:");

lcd.setCursor(7,1);

lcd.print(temperature);

lcd.setCursor(13,1);

lcd.print("F");

}