The Redesigning of a Pulse Oximeter

1. University of Pittsburgh Senior Design - BioE1160 The Redesigning of a Pulse Oximeter Jeffrey James Sam Audia Ted Askar Thomas Christophel

2. Pulse Oximeter Processor/ Monitor Background • What is a pulse oximeter? • A simple non-invasive tool for monitoring the percentage of • hemoglobin (Hb) which is saturated with oxygen.

3. Background (cont) • How does an oximeter work? • Light source originates from a LED at two wavelengths (650nm • and 805nm). • The light is partly absorbed by hemoglobin. • A processor calculates the absorption at the two wavelengths • and determines O2 concentration. Finger Monitor Receiver LED’s 90% 98% 70% 93% 85% 88% 70% 81% 76% 95% Blood vessel

4. Background (cont) • General Limitations • The oximeter is dependant on pulsatile flow and would • be unable to function when flow is sluggish (i.e. • during vasoconstriction) • Oximeters give no information about the level of CO2 • Accurate at oxygen saturations of 70 to 100% (+/-2%), • but less accurate under 70%…. Under 70% is fatal. • et, al. Fearnley

5. Overview • Product • A pulse oximeter with replaceable adhesive. • Alleviates problems involved with maintaining proper positioning of the device. • Intended solution • Design will be based upon current disposable pulse oximeters, but will incorporate a reusable sensor and replaceable adhesive. • Audience • Intended for patients using current pulse oximetry devices, specifically those who experience difficulties keeping the device positioned properly.

6. Project Goals • Design cost effective pulse oximeter that maintains accuracy of current designs • Design universal adapter to integrate replaceable device into current electronic monitoring systems • High level timing goals • Research • Design • Prototyping

7. Existing design problems • No universal connectors • Disposable pulse oximeter • costly • Clip/ Rubber slip • unstable attachment • only for the finger • Alarm • not discernable between situations

8. Design Alternatives • Removable adhesive • Universal connectors • Different alarm sounds for different situations

9. Features & Benefits • Replaceable Adhesive • Cost effective alternative to current disposable models • Maintains ability of disposable adhesive models to stay in place • Can be used on a variety of body parts • i.e. finger, toe, nose, forehead, or earlobe • Increased versatility • Universal Adapter • Can be integrated into electronics already in use

10. Adhesive Pulse oximeter Universal Connecter Professional Sketch

11. Competitive Analysis • Competitors • Nellcor • Disposable pulse oximeters • Costly due to nonreusability • Nonin, Minolta, BCI • Finger tip pulse oximeter • Portable • Costly ($300+)

12. Competitive Analysis (cont.) • Redesign Strengths • Inexpensive • Reusable • Multiple attachment sites (nose, ear, etc…) • Weaknesses • Disposable adhesive (additional purchases)

13. Modeling Strategy • Modeling and Analysis • Solidworks ANSYS • LabViewPspice Matlab

14. Team/Resources • Four highly skilled undergrads • Modeling and analysis software • Electronic equipment (breadboard, voltmeter, oscilloscope, etc…) • Locations/Support • St. Margaret’s Hospital (Mrs. Gartner) • The University of Pittsburgh (BEH B69)

15. Schedule (Gantt Chart)

16. Task List

17. Current Completions • Design History File • Product Design Specification • Objective Tree/ Functions-Means Analysis • Initial Hazard Analysis • Fault Tree Analysis • FMEA • Meeting with Mrs. Gartner • Obtained 2 pulse oximeters • Gantt Chart

18. Acknowledgements Senior Design - BioE1160 Dr. Gartner Mrs. Gartner Funding: The University of Pittsburgh

19. ¿Questions? ¿Comments? ¿Problems?