Quad-Rat Vitals Quad-Rat Vitals MonitorMonitorAdvisor: Paul ThompsonClient: Dr. Alex Converse

OverviewOverviewPET ImagingRequirementsExisting DevicesPrevious Semester’s WorkPulse Oximeter Probe Design

OptionsLabVIEW Interface Design OptionsWhere do we go from here?Acknowledgments

PET Imaging of RatsPET Imaging of RatsPositron

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 Requirements: Quads Vitals MonitorMonitorClient needs to simultaneously

monitor four rats1) SpO2 levels, accuracy of ±2%2) Heart rates up to 500 beats per

minute3) Respiratory rates of 20 to 30

breaths per minute4) Rectal temperatures of 93 - 100° F

Non-invasive probes and user-friendly interface

Existing DevicesExisting DevicesExisting 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 WorkPrevious Semester’s WorkDeveloped 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 General Probe RequirementsRequirementsApplicable for rats of varying sizeReusableSufficient blocking of ambient

lightCompatible LED and Photodiode

http://www.oximetry.org/pulseox/principles.htm

Foot ClipFoot ClipPros:

◦ Similar to current device

◦ Easy to reposition◦ Positioned far from

the headCons:

◦ Can displace easily◦ Risk of

LED/Photodiode misalignment

◦ Potential to apply excessive pressure

Foot WrapFoot WrapPros:

◦ No displacement once attached

◦ Alignment of LED/Photodiode maintained throughout testing

Cons:◦ Not adjustable◦ More involved

cleaning process

Tail ClipTail ClipPros:

◦ Easy to attach No confusion over

placement location

◦ AdjustableCons:

◦ May interfere with catheter in tail

◦ Potential to apply excessive pressure

Design Matrix – Pulse Oximeter Probe

Criteria (Weight)

Foot Clip Foot Wrap Tail Clip

Ergonomics(20)

18 12 14

Cost (5) 4 5 4

Accuracy (50)

46 46 35

Safety (10) 8 9 8

Durability (10)

9 6 9

Feasibility (5)

4 5 4

Total (100) 89 83 74

Four Corners with ButtonsFour Corners with Buttons

Full display

Four Corners with ButtonsFour Corners with ButtonsPros:

◦ Logical layout◦ Important

information visible

Cons:◦ Extra clicking◦ History graphs

incomparable◦ Less robust

A sample quarter of the final display

Tab InterfaceTab InterfacePros:

◦ Uncluttered interface

◦ Easy to program

Cons:◦ Inefficient◦ Data hard to

compare

Full display

Four Corners with Four Corners with HistoriesHistories

Full display

Four Corners with Four Corners with HistoriesHistories

Pros:◦ All data on one

screen◦ Easy to compare

trendsCons:

◦ Cluttered interface

◦ Tiny on small screen

A sample quarter of the final display

Design Matrix – LabVIEW InterfaceCriteria (Weight)

4 Corners with Buttons

Tabs 4 Corners with

Histories

Ergonomics (45)

38 25 44

Programming Feasibility (35)

26 32 30

Aesthetics (20)

15 18 14

Total (100) 79 75 88

Where do we go from Where do we go from here?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’ circuitPrint circuit boards Fabricate housing apparatus

AcknowledgementsAcknowledgementsProfessor Paul ThompsonDr. Alex ConverseAmit NimunkarTim BalgemannLiz AhlersNate Werbeckes

Questions?Questions?