The Redesigning of a Pulse Oximeter Jeffrey James Sam Audia University of Pittsburgh Senior Design - BioE1160 Ted Askar Thomas Christophel
Jan 02, 2016
The Redesigning of a Pulse Oximeter
Jeffrey James
Sam Audia
University of PittsburghSenior Design - BioE1160
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 OximeterProcessor/ Monitor
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.
LED’s Receiver
Finger
Blood vessel
98%
Monitor
95%93%90%88%85%81%76%70%70%
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• 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
Adhesive
Professional Sketch
Pulse oximeter
Universal Connecter
Competitive Analysis
• Competitors • Nellcor
• 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
Jeffrey James Ted Askar Sam Audia Tom Christophel
TasksDesign/ Modeling
Circuitry/ Prototype Testing Research Virtual Testing
Conceptual Design Acquire partsCurrent Devices/ Components ANSYS
Modeling Device/ Adhesive Assembly Costs Lab View
Finished Model/ Rapid Prototype Pilot Testing Hazards Pspice
Group Members
Subtasks
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
Acknowledgements
Senior Design - BioE1160
Dr. Gartner
Mrs. Gartner
Funding: The University of Pittsburgh
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