Mondialogo Engineering Contest

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Mondialogo Engineering Contest

• Multifunctional medical
• pre-screening device

Team 4
Thomas Wa-Jiw Casey Joe Hines Kurtis
Hessler Kevin Scheel Janelle Shane
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Introduction Mondialogo Engineering Contest

• UNESCO, DaimlerChrysler
• Humanitarian engineering projects
• Developed developing countries
• Contest deadline May 31

Our team Michigan State University HuaZhong
Univ. of Sci. Tech. University of Bologna
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Motivation Affordable health care in rural China

• lt 20 have medical insurance
• Cant afford regular checkups
• Dangerous delays
• Diagnosis
• Treatment

Goal free pre-screening for symptoms
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Design overview

• Single device that takes multiple medical
  measurements
• Temperature
• Blood pressure
• Glucose level
• Blood Oxygen/Pulse
• ECG
• Central PXA270 processor
• Touchscreen interface w/user-friendly GUI

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System design (MSU team)
Keyboard/mouse
Monitor
Blood pressure
Processor Motherboard w/Embedded Linux
RS-232 Hub/Switch
Glucose meter
Blood Oxygen
Flash memory
640x480 Touch Screen User Interface
Thermometer
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RS-232 Hub

• Receives protocols from GUI
• Powers on selected device
• Uses 18f4520 microcontroller

RS-232 Hub
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Power supply

• Salvaged computer power supply low-cost
  solution
• Provides 5V, 12V, -12V, 3.3V, gnd
• Used 12V for blood O2
• Used 5V for other modules
• Switching using TIP31A power transistors

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Thermometer

• Uses thermistor casing from commercial
  thermometer (100K Ohm)
• Thermistor voltage amplified by non-inverting
  op-amp
• Amplified voltage is read by ADC of 18f4520 PIC
• Digital voltage representation sent over RS232 to
  GUI

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Thermometer calibration

• Acquired series of points
• Curve fit yields equation relating voltage and
  temp.
• Accuracy of 0.08F over range 90-104F

• More than enough accuracy for pre-screening

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Blood Pressure

• Systolic diastolic pressure
• Uses arm cuff, pump, and pressure sensor
• Pressure sensor signal has
• oscillation signal (desired), 1Hz
• cuff pressure signal (unwanted), lt0.4Hz

Filtered oscillation signal
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Glucose measurement

• Spectrometer reads urinalysis
• test strips
• Measures reflected light from red, green,
  blue LEDs
• Detection using photoresistor
• Color identification using KNN algorithm

Image credit (top) http//www.cotc.edu/csimpson/ur
inary.htm, (center) http//www.irvingcrowley.com/
cls/urin.htm.
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Blood Oxygen

• 2 LEDs shine light through the finger
• Photodiode receives light
• Finger absorbs light differently
• depending on blood O2 level yields O2
  concentration

• For healthy person, we obtain values around
  97- 98 (normal range)
• As precise as we can test w/o clinical trial

Pulse waveform obtained by our Chinese partners
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User Interface

• Graphical program on ARM microprocessor
• running Linux
• Cross compiled GTK
• Touch screen for ease of use
• tslib drivers for X - Windows
• Device communication
• Linux RS-232 programming libraries lttermios.hgt
• Interface settings

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Summary

• Successful integration of modules into
  multifunctional device
• Variety of modules constructed and demonstrated
• Glucose meter and thermometer can be built for
  under 20 USD each.
• Blood pressure can be built for under 70 USD
• Cooperative effort w/ international team
• Humanitarian Impact

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Future Recommendations

• Further refinements to increase accuracy
• Clinical testing
• Patient database
• Picture-based GUI