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Pulse Oximeter Measuring Oxygen Saturation Levels. Final Presentation May 14, 2008 Tony Succar & Mustapha Okaddi. Table of Contents. Objectives Background Progress Results Responsibilities Timeline Conclusion. Objectives. To build a pulse oximeter
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Pulse OximeterMeasuring Oxygen Saturation Levels Final Presentation May 14, 2008 Tony Succar & Mustapha Okaddi
Table of Contents • Objectives • Background • Progress • Results • Responsibilities • Timeline • Conclusion
Objectives • To build a pulse oximeter • To achieve the Oxygen Saturation Level in blood by using two LED’s as transmitters and a Photodetector as the receiver. • An algorithm is developed through LabView
Background • The theory of measuring O2 levels in blood began in the 1930’s. • Observe the skin tones • Bluish skin color = Low Oxygen level = BAD • The Modern Pulse Oximeter was invented in 1978 by Dr. William New at Stanford University. • It was a breakthrough that paved the way for medical advances in the years to come. • Huge impact on prevention of diseases & illnesses.
Engineering Approach Photodiode
Principle • By calculating the light absorption of the two wavelengths, the processor can compute the proportion of oxygenated hemoglobin.
Principle • Oxygen saturation level is a direct function of the following ratio:
Stage 1 results • This setup was not effective • Numbers were inaccurate • Data was not stable • SpO2 was very low, less than 50% • Solution • Stabilize the Photo Detector • Mount the Photo Detector and LED’s onto the table or onto the same plate.
Stage 2 results • New Plastic Fixture • Numbers were greatly improved • Much more accurate • Much more stable • However, problems persisted… • Although much more stable and closer to the expected value, still it was not stable enough: • 60% < SpO2 < 95% • Ambient light would creep in and effect the photosensor • The pressure on the finger was not stable • This effects the accuracy of the data.
Stage 2 • Possible Solutions • Apply constant pressure to the finger • Block all external light sources from effecting the photosensor.
Results and Data • Our final design was the best design. • Data is accurate • Numbers are relatively stable • SpO2 is consistent • 90% < SpO2 < 97% • New clip fixture • Applied constant pressure to finger • Blocked all ambient light from effecting photosensor • Overall, our project was a success!
Responsibilities • Both of us met at the lab many times the past several months to build and test the oximeter. • Both of us worked together on the LabView program and simulated it with the oximeter.
