Design and Development of Microcontroller Based Pulse Oximeter

Nowadays, the risk of health is escalating and threatening millions of lives. Pulse oximetry has been recognized as a crucial tool to address a broad variety of chronic diseases such as obstructive pulmonary disease (e.g. emphysema, bronchitis), obstructive sleep apnea, asthma, cystic fibrosis, and

Project Title

Design and Development of Microcontroller Based Pulse Oximeter

Project Area of Specialization

Electrical/Electronic Engineering

Project Summary

Nowadays, the risk of health is escalating and threatening millions of lives. Pulse oximetry has been recognized as a crucial tool to address a broad variety of chronic diseases such as obstructive pulmonary disease (e.g. emphysema, bronchitis), obstructive sleep apnea, asthma, cystic fibrosis, and different cardiovascular ailments. It has a critical role in the diagnosis of pediatric pneumonia, sepsis and is used during surgeries to monitor patients.

In this project, we are going to make a device that can measure Blood Oxygen Concentration & Heart Rate using a pulse Oximeter sensor. The device has two LEDs, one emitting red light with a wavelength of 660 nm, another emitting infrared light with a wavelength of 940 nm. For pulse rate, only infrared light is needed. Both red light and infrared light is used to measure oxygen levels in the blood. On the other end, there’s a receiver that measures how much light passes through. The diode on the receiving end is capable of detecting the wavelength of light. The internal circuits and processing components of the pulse oximeter do some calculations as well.

The microcontroller is connected to the pulse oximeter sensor, to process the signal from the sensor and then the data is shown on the display screen. We will embed the code of the desired language in the microcontroller of the oximeter accordingly. 5 or 9 volt DC battery will be used for power purposes. The blood Oxygen Concentration termed SpO2 is measured in Percentage and the Heart Beat/Pulse Rate is measured in BPM. We will display the SpO2 and BPM values on LCD/LED, mobile or computer screen. By using a Bluetooth module or data cable we can also send data to the mobile or computer, and monitor the data on the screen as well and keep a track record of the data in the text format. The construction was purposely kept intelligible for everyone, and taking into consideration for future up-gradation and improvement, and retaining the development and production cost very low.

Project Objectives

1. Microcontroller based pulse Oximeter to monitor a patient's pulse rate and blood-oxygen saturation with +/- 5% tolerance.
2. Pulse Oximeter Sensor consists of two LEDs, red and infrared, a photodetector and low-noise analog signal processing to detect pulse and heart-rate signals.
3. SpO2 and BPM values will be displayed on LCD/LED, mobile or computer screen.

Project Implementation Method

Microcontroller-based pulse Oximeter will be designed and developed on an economical and frugal way to keep the cost very low. Lithium-ion battery will be used for power purposes. We use Pulse Oximeter with microcontroller kit and display the Heart Rate and Blood Oxygen on a LCD/LED, mobile or computer screen and also send the blood oxygen and heart rate or Pulse rate values to the mobile application through the wireless Bluetooth technology. By using the mobile app we can save our money and track the record of the data in text format. Apart from that, we can also send the data read from the device to another device or to the internet. Pulse oximeter sensor shines two light beams of different wavelengths (red with a wavelength of 660 nm, and infrared light with a wavelength of 940 nm) through the blood that is circulating in the small blood vessels of the finger, and then detects the amount of light that is able to pass through the extremity. Hemoglobin carrying oxygen (red blood) absorbs more infrared light and allows more red light to pass than hemoglobin without oxygen (blue blood) which allows more infrared light to pass.

The Heart rate or Pulse rate or Heartbeat is measured in BPM which is also known as the beats per minute while the Blood Oxygen Concentration is measured in percentage and displayed on the screen.

Benefits of the Project

Today different types of Pulse Oximeter are used for different purposes. Nowadays Pulse Oximeter is becoming very popular. A Pulse Oximeter is an instrument that is used to rapidly and comfortably monitor and check a person or patient’s oxygen saturation and Heart Beat/Pulse Rate (BPM). This means that it can measure the level of oxygen inside the blood, particularly in arterial blood without utilizing any invasive means.

Each and every system and organ in the body requires oxygen to remain alive. Without oxygen, cells begin to improper functioning and finally die. Cell death can create very serious symptoms and eventually cause organ failure. The body transfers oxygen to the organs by filtering it through the lungs. The lungs then distribute oxygen into the blood by means of hemoglobin proteins in red blood cells (RBCs). These proteins supply oxygen to the rest of the body. Pulse oximetry measures the percentage of oxygen in hemoglobin proteins, called oxygen saturation. Normal oxygen saturation levels are between 95 and 100 percent. Oxygen saturation levels beneath 90% are considered abnormally low and can be a clinical emergency.

Pulse oximeters are very convenient for those people who have such type of conditions that affect oxygen saturation. For instance, a sleep specialist may suggest a pulse oximeter to monitor the nighttime oxygen saturation level of someone with suspected sleep apnea or severe snoring. This can also provide a response about the efficiency of breathing interventions. For example, oxygen therapy and ventilators. Some doctors also use this tool to evaluate the safety of physical activity in people with cardiovascular or respiratory diseases, or even recommend that a person use a pulse oximeter during exercise. In most hospitals pulse oximeters also used for particularly vulnerable patients. For example, infants in neonatal intensive care units may wear pulse oximeters, which can alert medical staff and doctors of a drop in oxygen saturation. Pulse oximetry is regularly used to monitor patients who are under anesthesia during surgery. 

Some other uses of pulse oximeter are the following:  

1. Monitor oxygen saturation levels in people under anesthesia
2. Monitoring oxygen saturation over time  
3. Warning to dangerously low oxygen levels, particularly in newborn babies
4. Presenting peace of mind to people with chronic respiratory or cardiovascular conditions
5. Indicating perilous side effects in people taking drugs that affect breathing or oxygen saturation

But these assessments and measurements have gained momentum during this COVID-19 pandemic.

We will first design the prototype of the Pulse Oximeter and after that, we will design the actual product of that prototype. So, this will create a large number of jobs here in our country Pakistan. Apart from that, this will reduce the import of this equipment and increase the export ratio of these types of equipment.

Technical Details of Final Deliverable

1. Design a Prototype of Pulse Oximeter.
2. Design and Development of the Actual Product of Microcontroller based pulse Oximeter to monitor a person's pulse rate and blood-oxygen saturation.
3. The Oxygen (O2) saturation and Heart Beat/Pulse Rate will be displayed on LCD/LED, mobile or computer screen.

Final Deliverable of the Project

Hardware System

Core Industry

Medical

Other Industries

Health

Core Technology

Wearables and Implantables

Other Technologies

Others

Sustainable Development Goals

Good Health and Well-Being for People

Required Resources

If you need this project, please contact me on contact@adikhanofficial.com