Engineering World Health Temperature Tester Team: Carly Brown, Sarah Offutt, Ryan Thome, Sasha Cai Lesher-Perez BME 201 February 24, 2006

Client: John Webster, Ph.D. Dept. of Biomedical Engineering University of Wisconsin Advisor: Paul Thompson, Ph.D. Dept. of Biological Systems Engineering University of Wisconsin

Overview Problem Statement Problem Statement Background Background Proposed Designs Proposed Designs Future Work Future Work Questions Questions

Problem Statement We will design a temperature tester that indicates changes in a water bath or incubator temperature by more than half a degree from a specified temperature of 37 ° C

PDS Summary Size: 1”x1”x4” Size: 1”x1”x4” Water Resistant Water Resistant $3.00 per unit in quantities of 500 $3.00 per unit in quantities of 500 Accuracy:.1° C Accuracy:.1° C Operating Temperature: 17-45° C Operating Temperature: 17-45° C

Background Water Baths Water Baths Heating beakers Break up kidney stones Incubator Incubator Premature babies Biological cultures Drug stability testing _image.asp?img= jpg

Background…Continued Current Products Current Products Ice-Box Alarm ThermometerIce-Box Alarm Thermometer Audible alarms and flashing LEDs Audible alarms and flashing LEDs Pre-set temperature range Pre-set temperature range $19.00 $19.00 Traceable Alarm ThermometerTraceable Alarm Thermometer Audible alarm Audible alarm ±2° C accuracy ±2° C accuracy $30.76 $

Internal Circuit 9 V Battery 9 V Battery 100kΩ Thermistor 100kΩ Thermistor 5-10kΩ Potentiometer 5-10kΩ Potentiometer Comparator Comparator LEDs LEDs Switch Switch

Alt. Design 1: Disposable Key Features Key Features Non-removable battery Single, enclosed unit Fully submersible Rests on bottom of incubator

Alt. Design 1: Disposable Advantages Advantages Ease of use Simple Design Easier to manufacture Disadvantages Disadvantages Short life span Less cost effective Visual alarm is more difficult to see

Alt. Design 2: Replaceable Battery Key Features Key Features Removable battery Separate battery compartment Fully submersible Rests on bottom of incubator

Alt. Design 2: Replaceable Battery Advantages Advantages Longer lifespan More cost effective Simple Design Ease of use Disadvantages Disadvantages Visual alarm is more difficult to see Harder to manufacture and make submersible

Proposed Design: Probe Key Features Key Features Flexible probeFlexible probe Thermistor incased in probeThermistor incased in probe Removable batteryRemovable battery Suctioned backingSuctioned backing

Proposed Design: Probe Advantages Advantages Longer lifespanLonger lifespan Ease of useEase of use Visual alarm is more visibleVisual alarm is more visible Flexible probeFlexible probe Disadvantages Disadvantages Whole unit is largerWhole unit is larger More complicated design and manufactureMore complicated design and manufacture

Design Matrix 1 = Poor & 5 = Excellent DesignDisposableRemovable BatteryProbe Cost244 Portability (size, weight) 443 Reliability225 Ease of Manufacturing 432 Ease of Use335 Complexity of Design 432 Totals19 21

Future Work Finalize casing and materials Finalize casing and materials Finish and submit proposal to EWH Finish and submit proposal to EWH Build Final Prototype Build Final Prototype Test Prototype Test Prototype CalibrationCalibration

References Allina Hospitals & Clinics. (2005, March). Laser Lithotripsy. Retrieved February 12, 2006 from Pacific Link. (2005, September). Incubators. Retrieved February 12, 2006 from Fotosearch. (2005, February). Stock Photos of Baby Incubators. Retrieved February 5, 2006 from ThermoWorks. (2004, November). Low Cost Digital Thermometers. Retrieved February 5, 2006 from Control Company. (2006, January). Traceable Alarm Thermometer/Alarm Timer. Retrieved February 5, 2006 from Webster, John G. (2003). Bioinstrumentation. Indianapolis, IN: John Wiley & Sons Inc.

Questions?