Quad-Rat Vitals Monitor

Advisor: Paul Thompson Client: Dr. Alex Converse

Overview

        PET Imaging Requirements Existing Devices Previous Semester’s Work Pulse Oximeter Probe Design Options LabVIEW Interface Design Options Where do we go from here?

Acknowledgments

PET Imaging of Rats

  Positron emission tomography (PET) scans to monitor location of tracers in rats Client scans four anesthetized rats at a time ◦ Needs to monitor the rats’ vitals http://homepages.cae.wisc.edu/~bme300/rat_monitor _s09/reports/FinalPaperSpring09.pdf

Requirements: Quads Vitals Monitor   Client needs to simultaneously monitor four rats 1) SpO 2 levels, accuracy of ±2% 2) Heart rates up to 500 beats per minute 3) 4) Respiratory rates of 20 to 30 breaths per minute Rectal temperatures of 93 - 100° F Non-invasive probes and user-friendly interface

Existing Devices

 Existing devices: ◦ Client currently uses rudimentary devices to monitor vitals ◦ Available: Pulse oximeter for mice and rats  Over $7000, one rat at a time http://www.starrlifesciences.com/mri.html

Previous Semester’s Work

    Developed circuit for detecting breathing rate using force sensing resistor Designed and calibrated thermistor to detect temperature Designed Graphical User Interface (GUI) in LabVIEW displaying breathing rate and temperature Attempted to reverse engineer existing Pulse Oximeter Force sensing resistor LabVIEW interface

General Probe Requirements

 Applicable for rats of varying size    Reusable Sufficient blocking of ambient light Compatible LED and Photodiode http://www.oximetry.org/pulseox/principles.htm

Foot Clip

  Pros: ◦ ◦ Similar to current device Easy to reposition ◦ Positioned far from the head Cons: ◦ Can displace easily ◦ Risk of LED/Photodiode misalignment ◦ Potential to apply excessive pressure

Foot Wrap

  Pros: ◦ No displacement once attached ◦ Alignment of LED/Photodiode maintained throughout testing Cons: ◦ Not adjustable ◦ More involved cleaning process

Tail Clip

  Pros: ◦ Easy to attach  No confusion over placement location ◦ Adjustable Cons: ◦ May interfere with catheter in tail ◦ Potential to apply excessive pressure

Design Matrix – Pulse Oximeter Probe

Criteria (Weight) Ergonomics(20) Foot Clip 18 Foot Wrap 12 Tail Clip 14 Cost (5) Accuracy (50) Safety (10) Durability (10) Feasibility (5) Total (100) 4 46 8 9 4 89 5 46 9 6 5 83 4 35 8 9 4 74

Four Corners with Buttons

Full display

Four Corners with Buttons

  Pros: ◦ Logical layout ◦ Important information visible Cons: ◦ Extra clicking ◦ History graphs incomparable ◦ Less robust A sample quarter of the final display

Tab Interface

 Pros: ◦ Uncluttered interface ◦ Easy to program  Cons: ◦ Inefficient ◦ Data hard to compare Full display

Four Corners with Histories

Full display

Four Corners with Histories

  Pros: ◦ All data on one screen ◦ Easy to compare trends Cons: ◦ Cluttered interface ◦ Tiny on small screen A sample quarter of the final display

Design Matrix – LabVIEW Interface

Criteria (Weight) Ergonomics (45) Programming Feasibility (35) Aesthetics (20) Total (100) 4 Corners with Buttons 38 26 15 79 Tabs 25 32 18 75 4 Corners with Histories 44 30 14 88

Where do we go from here?

    Finish LabVIEW GUI ◦ Determine how data will be collected from Pulse Oximeter Design pulse-ox probe to fit rat’s hind paw ◦ Integrate with signal received from Graduate Students’ circuit Print circuit boards Fabricate housing apparatus

Acknowledgements

      Professor Paul Thompson Dr. Alex Converse Amit Nimunkar Tim Balgemann Liz Ahlers Nate Werbeckes

Questions?