Pulse Oximeter Measuring Oxygen Saturation Levels Final Presentation May 14, 2008 Tony Succar & Mustapha Okaddi

Table of Contents Objectives Objectives Background Background Progress Progress Results Results Responsibilities Responsibilities Timeline Timeline Conclusion Conclusion

Objectives To build a pulse oximeter 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 An algorithm is developed through LabView

Background The theory of measuring O 2 levels in blood began in the 1930’s. The theory of measuring O 2 levels in blood began in the 1930’s. –Observe the skin tones Bluish skin color = Low Oxygen level = BAD Bluish skin color = Low Oxygen level = BAD The Modern Pulse Oximeter was invented in 1978 by Dr. William New at Stanford University. 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. 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: Oxygen saturation level is a direct function of the following ratio:

Stage 1: The beginning…

Stage 1 results This setup was not effective This setup was not effective –Numbers were inaccurate –Data was not stable –SpO2 was very low, less than 50% Solution Solution –Stabilize the Photo Detector Mount the Photo Detector and LED’s onto the table or onto the same plate. Mount the Photo Detector and LED’s onto the table or onto the same plate.

Stage 2: Improvements Applied

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 Possible Solutions –Apply constant pressure to the finger –Block all external light sources from effecting the photosensor.

Stage 3: Final Design

LabView Data from Final Design

Results and Data Our final design was the best design. Our final design was the best design. –Data is accurate –Numbers are relatively stable –SpO2 is consistent 90% < SpO2 < 97% 90% < SpO2 < 97% New clip fixture New clip fixture –Applied constant pressure to finger –Blocked all ambient light from effecting photosensor Overall, our project was a success! 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 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. Both of us worked together on the LabView program and simulated it with the oximeter.

Time Line

Any Questions or Comments?? Any Questions or Comments??