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

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

Background (cont) 81% 76% 70% 85% 70% 95% 98% 88% 93% 90% 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 LED’s Receiver 81% 76% 70% 85% 70% 95% 98% 88% 93% 90% Blood vessel

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

Overview Product Intended solution Audience 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.

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

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

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

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

Professional Sketch Adhesive Pulse oximeter Universal Connecter

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

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

Modeling Strategy Modeling and Analysis Solidworks ANSYS LabView Pspice Matlab

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)

Schedule (Gantt Chart)

Task List

Current Completions Design History File Meeting with Mrs. Gartner 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

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

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