Therma-STAT! A Reusable, Hands-Free, Reliable Thermometer to Detect Fever in Infants

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1 Therma-STAT! A Reusable, Hands-Free, Reliable Thermometer to Detect Fever in Infants Sarah Hill, Dana Novak Dr. Mansoor Nasir Department of Biomedical Engineering, Lawrence Technological University

2 We created an infant thermometer that is reliable, comfortable, and hands free

3 Fever in Infants Fever Phobia is a predominant fear among parents that their child s fever is caused by a serious illness. Fever: Most common reason why parents bring their children to ER Aggressive treatment of fever Unnecessary ER visits Infants (0-3 months) have a limited immune system

4 Existing Solutions Cheap Expensive Cheap Inaccurate Inconvenient Inconvenient

5 Therma-STAT! Class I Device Palm Sized Reusable (Adhesive patch) Placed on infants torso directly below the armpit Use two thermistors (for Accuracy)

6 Design Components

7 Internal Circuits 1 2

8 Testing Single Thermistor Components: QTI 2252 Ω Thermistor, 2 Ω Resistor, Arduino Uno Board Bulb Thermometer Voltage Divider Circuit Beaker 1 (Low) Beaker 2 (High) Beaker Setup for Testing Heater Heater

9 Thermistor Calibration (1 Thermistor) Thermistor measurements compared to axillary thermometer Results: 10 point data averaging Steinhart-Hart Average most accurate Response Time Average = 16 sec

10 Thermistor Calibration (2 Thermistors) Procedure: Readings taken w/ 2 thermistors in same temperature conditions Results: Thermistor values follow linear trend with offset no greater than 0.6 C, at temperatures below 30 C

11 Finalized Code Ensures Accuracy Average of 10- Thermistor 1 Readings Average of 10- Thermistor 2 Readings Readings Averaged IF: 2 Readings within 0.5 F Print to Screen

12 Silicone Ratio Test Materials: Smooth-On Ecoflex TM and Slacker Results: A > B or A < B Stiffer Material A > B Less Tacky A < B More Tacky Further Testing: Casing Ratio: 1A:1B vs 4A:1B Adhesive Ratio: 1A:1B:0.8S vs 1A:2B:0.8S

13 Material Stiffness Test Casing Samples: 3mm thickness 200g Weight Adhesive Samples: 2mm thickness 100g Weight

14 Material Stiffness Results 4A:1B and 1A:1B:0.8S are both stiffer than their respective counterparts. Casing Ratio: 4A:1B

15 Adhesive Stickiness Testing Suspended Weight: 300g Adhesive Placed Here

16 Adhesive Stickiness Results Results: Adhesives proven to be reusable up to 5 times. 1A:1B:0.8S sticks to surface longer. Adhesive Ratio: 1A:1B:0.8s

17 Assembly Test Left to Right: Loctite Super Glue Gel, Loctite Epoxy Instant Mix Loctite Silicone Sealant Gorilla Glue Silicone Sealant Results: From worse to best: LT. Expoxy < LT. Super Glue < LT. Sealant = GG. Sealant

18 Summary of Results Thermistor Testing Steinhart-Hart equation more accurate 10 averages of analog pin readings improves accuracy Response time: 16 sec No variations in temp > 0.6 C w/ two thermistors Material Stiffness Testing Casing Ratio 4A:1B Adhesive Stickiness Testing Adhesive Ratio 1A:1B:0.8S Assembly Testing Gorilla Glue Silicone Sealant

19 Deviations from Original Design

20 Modifications for Future Design Iterations Integrate accessory components (Light, ON/OFF Button) Edit and test code to further improve usability Test and compare silicone casing/adhesive to similar materials on the market Test accuracy of Therma-STAT! and compare to other available devices

21 Market Analysis Current Market Avg. # births/year ~3,978,497 [6] Stakeholders Parents/Any Caregiver of infants ~19-23 million<5 years [7] 4 million - $ 240 million in Thermometer Sales [8] Needs are met in hospital environment Needs not met in the in-home environment

22 Timeline of Project

23 Cost of Product Component # of Units Price Cost of 500 Devices Microprocessor 100 $1, $9, Display Screen 100 $1, $7, Thermistor (2) 1000 $5, $5, Silicone Ecoflex (Gallon) 135 $ $ Slacker (Gallon) 1260 $ $ D Printed Bedding 250 $19.99 $39.98 Batteries 100 $86.00 $ Battery Casing 100 $ $ LilyPad LED Yellow (5) 100 $ $1, Price per Single Unit Button 500 $ $ Total $25, $51.01

24 Acknowledgements We would like to thank the Department of Biomedical Engineering for funding our project and QTI Sensing Solutions for providing thermistor samples.

25 Therma-STAT! A Reusable, Hands-Free, Reliable Thermometer to Detect Fever in Infants Sarah Hill, Dana Novak Dr. Mansoor Nasir Objective: To create a reliable, comfortable, and hands-free thermometer for infants. Impact: Reduce unnecessary trips to medical centers. Parents ease of mind. Progress and Results: 1. Steinhart-Hart averaged most accurate 2. Response time: 16 sec 3. Casing Ratio 4A:1B 4. Adhesive Ratio 1A:1B:0.8S 5. Gorilla Glue Silicone Sealant for Assembly