Simulating a Heart Rate Monitoring System with Alert

Objective:
Students will design and simulate a heart rate monitoring system using a simulated sensor to detect the
heart rate. When the heart rate exceeds a predefined threshold, an alert will be triggered (simulated
with an LED or buzzer). This exercise introduces students to health monitoring systems and alert
mechanisms.

Requirements:

 Laptop with internet access

 Free account on Tinkercad or Wokwi

 Basic knowledge of Arduino programming

 Understanding of health monitoring systems

Step-by-Step Instructions:

1. Setup the Simulation Environment (5 minutes):

 Log in to Tinkercad or Wokwi.

 Create a new Arduino project.

2. Design the Heart Rate Monitoring System (10 minutes):

 Drag and drop the following components into the simulation workspace:

o Arduino Uno

o Simulated Heart Rate Sensor (can be represented by a potentiometer to simulate heart

o LED (to simulate the alert or a visual indicator)

o Buzzer (optional, to simulate the alert sound)

o Resistor (for the LED and buzzer)

o Breadboard (optional, depending on the simulator)

 Wire the components:

o Connect the Heart Rate Sensor (simulated with a potentiometer) to an analog input pin
(e.g., pin A0).

o Connect the LED to a digital output pin (e.g., pin 9) and ground, with a resistor (220Ω) to
limit current.

o Connect the Buzzer to a digital pin (e.g., pin 10) and ground (optional).

3. Program the Arduino (20 minutes):

cpp

CopyEdit

#define HEART_RATE_SENSOR_PIN A0 // Pin connected to the heart rate sensor (simulated with
potentiometer)

#define ALERT_LED_PIN 9 // Pin connected to the LED (alert visual indicator)

#define BUZZER_PIN 10 // Pin connected to the buzzer (alert sound)

int heartRateValue = 0; // Variable to store heart rate sensor value

int threshold = 100; // Threshold for heart rate (bpm, adjustable)

void setup() {

pinMode(ALERT_LED_PIN, OUTPUT); // Set the LED pin as output

pinMode(BUZZER_PIN, OUTPUT); // Set the buzzer pin as output

Serial.begin(9600); // Start serial communication for debugging

void loop() {

// Read the heart rate value from the sensor (simulated with potentiometer)

heartRateValue = analogRead(HEART_RATE_SENSOR_PIN);

// Convert the sensor value to heart rate (simulated scaling)

int heartRate = map(heartRateValue, 0, 1023, 60, 150); // Mapping sensor value to heart rate range (60-
150 bpm)

// Print the heart rate value to the serial monitor for debugging

Serial.print("Heart Rate: ");

Serial.println(heartRate);
 // Check if the heart rate exceeds the threshold and trigger an alert

if (heartRate > threshold) {

digitalWrite(ALERT_LED_PIN, HIGH); // Turn on the LED to indicate alert

digitalWrite(BUZZER_PIN, HIGH); // Turn on the buzzer to indicate alert

Serial.println("Alert! Heart rate exceeded threshold.");

} else {

digitalWrite(ALERT_LED_PIN, LOW); // Turn off the LED

digitalWrite(BUZZER_PIN, LOW); // Turn off the buzzer

delay(500); // Delay for half a second before reading again

Explanation of the Code:

 The Heart Rate Sensor (simulated with a potentiometer) is used to read values that represent
heart rate fluctuations.

 The value from the potentiometer is mapped to a range of heart rate values (e.g., 60–150 bpm).

 If the heart rate exceeds the predefined threshold (e.g., 100 bpm), the system triggers an alert
by turning on an LED and activating a buzzer.

 The Serial Monitor prints the current heart rate value for debugging.

4. Run and Test (15 minutes):

 Start the simulation.

 Adjust the potentiometer to simulate changes in heart rate (e.g., slowly increase or decrease the
potentiometer value).

 Observe the LED turning on and the buzzer sounding when the heart rate exceeds the threshold.

 Verify that the system deactivates the alert when the heart rate goes back below the threshold.

5. Discussion and Reflection (10 minutes):

 Real-Time Monitoring:
Discuss how this system simulates a real-time health monitoring process. Real-world systems like
heart rate monitors or fitness trackers often use similar principles to measure and alert users
about potential health risks, such as tachycardia (rapid heart rate).
  Threshold Adjustment:
Discuss how heart rate thresholds should be personalized depending on the individual’s health
status, age, or fitness level. For example, a threshold of 100 bpm may be high for some
individuals but normal for others.

 Importance of Alerts in Health Systems:

 Extensions:
Suggest possible extensions to the system:

o Use a real heart rate sensor (e.g., pulse sensor) instead of the potentiometer to read
actual heart rate values.

o Implement multiple thresholds for different alert levels (e.g., yellow alert for mild
elevation, red alert for dangerous heart rates).

o Integrate a screen (e.g., LCD) to display the current heart rate.

o Implement an IoT solution where heart rate data can be sent to a smartphone or a web
application for real-time monitoring.

This exercise introduces students to health monitoring systems and teaches them how to handle real-
time sensor data. It can be further extended to simulate more complex medical devices or systems,
making it highly relevant for applications in health and fitness technology.