How does a fingertip pulse oximeter work?

Table of Contents

1. Introduction
2. Principle of Operation
3. Key Components
4. Measurement Methodology
5. Leis Company Solutions
6. References

Introduction

A fingertip pulse oximeter is a non-invasive device that assesses oxygen saturation level (SpO2) and pulse rate of an individual. This device is crucial in clinical settings to monitor patients who require regular assessment of their blood oxygen levels.

Principle of Operation

The core principle behind a fingertip pulse oximeter involves light absorption characteristics of oxygenated and deoxygenated hemoglobin. The device uses two light-emitting diodes (LEDs), typically red and infrared, which pass light through the pulsating tissue to a photodetector on the opposite side.

Key Components

• LEDs: Emit red (660 nm wavelength) and infrared (940 nm wavelength) light.
• Photodetector: Captures the light that passes through the fingertip.
• Microprocessor: Analyzes the ratio of absorbed red and infrared light to compute SpO2 levels.
• Display: Shows real-time SpO2 and pulse rate readings.

Measurement Methodology

The device calculates oxygen saturation using the ratio of absorbed red and infrared light. The Beer-Lambert law is applied for this calculation. In general, oxygenated hemoglobin absorbs more infrared light and allows more red light to pass through, while deoxygenated hemoglobin absorbs more red light.

The formula used is:

SpO2 = (HbO2 / (HbO2 + Hb)) x 100%

Where:

• HbO2 represents oxygenated hemoglobin.
• Hb represents deoxygenated hemoglobin.

Data accuracy typically ranges between 70% and 100% SpO2 with a standard deviation of ±2% at the 95% confidence level.

Leis Company Solutions

Leis Company offers cutting-edge fingertip pulse oximeters featuring advanced signal processing techniques to enhance measurement accuracy even in low perfusion scenarios. The devices often include Bluetooth connectivity for data transfer to mobile applications, enabling remote monitoring and data analysis.

Key product features include:

• Data storage for up to 24 hours.
• Battery life exceeding 30 hours on a single charge.
• Compatibility with multiple smartphone operating systems.

References

• Jubran, A. (2015). Pulse oximetry. Critical Care, 19(1), 209.
• Sinex, J. E. (1999). Pulse oximetry: principles and limitations. The American Journal of Emergency Medicine, 17(1), 59-67.
• Lanatos, C. A., Chen, Z., & Armoundas, A. A. (1998). A case study on the accuracy of pulse oximetry with low perfusion. Journal of Clinical Monitoring and Computing, 14(6), 409-412.