Design and Implementation of a Compact, User-Friendly Incentive Spirometer for Enhanced Mobility and Discretion

This project focused on developing a discreet and portable incentive spirometer tailored to the specific needs of our client, Trevor. His primary concerns were discretion and portability, as he frequently travels and requires a device that doesn't draw attention in public or office settings. Our design reimagines the traditional spirometer into a compact, smart-device-like form that prioritizes user-friendliness and aesthetics.

Technical Specifications and Innovations:

• Inspiratory Volume and Resistance: Aligned with standard medical devices, the inspiratory resistance mirrors commercial units, requiring a 4-second inhale to reach a volume of 500 ml, translating to a flow rate of approximately 125 ml/s.

• Hygiene and Maintenance: All components exposed to airflow are easily cleanable using either surface wipes or sterilizing fluid, supporting maintenance in varied environments, including on-the-go scenarios.

• Design Enhancements: The device eliminates cumbersome tubing and integrates the piston and indicator within a sleek, handheld unit. This format significantly reduces the device's size, aligning it with the form factor of a smart device.

Mechanical Design and Components:

The incentive spirometer incorporates several key features:

Mouthpiece: Direct air intake, designed for ease of use and to prevent external contamination.

One-Way Valve: Ensures inhalation only, enhancing the effectiveness of the exercise.

Flow Indicator: Utilizes a visible piston mechanism, allowing users to monitor their inhalation progress accurately.

Compact Structure: Emphasizes a handheld design for enhanced portability and discretion.

Electronics and Functionality:

The device integrates a simple electronic system to enhance user interaction:

IR LED and Photodiode: These components are positioned to detect the optimal position of the flow indicator, ensuring precise user feedback.

LED Notification: A green LED alerts the user when the flow rate is within the optimal range, aiding in consistent and effective usage.

Code Explanation:

The embedded system utilizes a basic C++ program to manage sensor inputs and outputs. Here’s a breakdown of the code:

// Define pin numbers for the photodiodes and the infrared LED

const int photoDiodePin1 = A10; // Analog input pin connected to the photodiode

int photoDiodeValue1 = 0;       // Variable to store the photodiode input value

void setup() {

  Serial.begin(9600);          // Start serial communication at 9600 baud

  pinMode(photoDiodePin1, INPUT); // Set the photodiode pin as an input

}

void loop() {

  photoDiodeValue1 = analogRead(photoDiodePin1); // Read the value from the photodiode

  Serial.print("Photodiode 1: ");

  Serial.println(photoDiodeValue1);  // Print the value to the serial monitor

  delay(1000); // Wait for a second before the next reading

}

This code snippet is instrumental in facilitating real-time data collection from the respiratory effort, enabling immediate feedback via the integrated display system.