BME 4202 Projects II Midterm Report. Project Therma-STAT! Team Temp Watch. Dana Novak, Sarah Hill. Lawrence Technological University

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1 BME 4202 Projects II Midterm Report Project Therma-STAT! Team Temp Watch Dana Novak, Sarah Hill Lawrence Technological University Advisors: Dr. Mansoor Nasir, Dr. Michael Lancina March 2, 2018

2 Contents Updated Timeline... 3 Key Dates... 3 Task List... 4 Current... 4 Future... 5 Major Changes... 6 Accomplishments... 6 Testing... 7 Current... 7 Silicone Ratio Testing for Adhesive/Casing... 7 Non-Contact Thermistor Testing:... 8 Addition and Testing of Second Thermistor Circuit:... 9 Future Adhesive/Casing Tensile/Torsion Testing Contact Temperature Testing Tasks Completed/Assigned Contributions Updated Bill of Materials Meeting Minutes/Communications with Members and Advisors January 18, 2018 Advisor Meeting February 14, 2018 Advising Meeting Appendix... 14

3 Updated Timeline Key Dates

4 Task List Current

5 Future

6 Major Changes There have been some major changes that have been made over the course of the project. The main change being the design and sizing of the patch prototype. After gathering our components and using their dimensions to redesign the layout of our patch. The shape has changed from a rectangle to have one side circuit (houses the microprocessor, display screen, on/off button, and light) and a rectangle end (houses the thermistors and other circuits). The middle portion that connects the two ends is rectangular and houses the batteries for the patch. The batteries will not be removable in this design but we hope to incorporate removable batteries in the future. The design is our third version of our patch. Picture of patch design version 3 in Appendix (Figure A3-A5). Another major change is on the adhesive that we will be using for our patch. We are leaning toward a two part silicone mixture with added slacker for the adhesive instead of using the TENS electrode. There are several reasons for this change. One is that by changing the ratio between the silicone parts and the slacker, we can make the adhesive as sticky as we want. Another reason for this change is that the fact that we can mold the silicone to the shape we need. With the TENS electrode, we would have to incorporate the adhesive from pre-made electrodes into our design so the entire underneath of the patch will not have the adhesive like we want. The last reason for the change is that the silicon seems to leave less of a residue after being stuck to something as when compared to the TENS electrode. More testing will be made in order to determine if we officially decide to make the switch over. Accomplishments One of our first accomplishments was 3D printing our second patch design to see the dimensions of it in real life. It was a crude print job but it allowed us to better visualize the size and component layout inside the patch. Picture of patch design version 2 in Appendix (Figure A1-A2). The next accomplishment was the resign of our patch to create our version 3 design. This new design is discussed in greater detail under that Major Changes portion of this report. The third accomplishment of ours was to have our complete IRB approved after 2 weeks of deliberation. The adult portion was easily approved but the Dr. Cole showed some reserves about the infant portion. After discussing the infant testing more with Dr. Cole, the infant portion was able to be approved as well. The fourth accomplishment was the thermistor testing methodology that was used was proven accurate and will continue to be used for the rest of the testing.

7 Testing Current Silicone Ratio Testing for Adhesive/Casing a. Purpose: The purpose of the silicone ratio test is to discover the golden ratio of Silicone Parts A and B combined with Slacker. The adhesive needs to be sticky but still be stiff enough to retain its shape and resist ripping from tensile and torsion forces. On the other hand the casing needs to be stiff but also flexible. The casing should also not have any stickiness to it. b. Ratios: The silicone parts A and B are set in a 1:1 ratio in all tests. The changing ratio is only between the silicone parts and the slacker. Figure 1: Initial testing ratios and volumes for adhesive testing. Figure 2: Initial testing ratios and volumes for casing testing. c. Procedure: The mixing process is as follows:

8 i. Each substance has ingredients that can rest at the bottom. For best results, the substances must be mixed before combining with each other. ii. Use 6mL oral syringe to take out a portion from each substance container and place in a cup for easy access when measuring. iii. Measure out Part B silicone and place in a cup. Measure out Slacker and add it to Part B. Mix together for for at least 1 minute. iv. Measure out Part A silicone and add to Part B/Slacker mixture. Mix together for at least 3 minutes. v. Let rest to cure for 4 hours before removing from cup. Non-Contact Thermistor Testing: a. Purpose: The purpose of this testing is to be able to establish both the accuracy of the measurements and response times of our created circuit. This will be done by comparing measurements of our created circuit, to the comparable devices, Temp Traq and Fever Scout, along with a Dollar store axillary thermometer, and a grove temperature sensor used in conjunction with a Arduino board. All testing will be done in the same environment to allow for direct comparison, to determine the accuracy of our created circuit, and the device with the best accuracy and response over all. b. Procedure: i. A FeverScout Thermometer, Dollar Store Axillary Thermometer, Created ThermaSTAT! Circuit, Grove Temperature Sensor, Arduino, Laptop, Phone, Timer, and Oven will be used ii. This testing will be conducted in the LTU MEMs laboratory iii. iv. This testing will be repeated multiple times (3-5 times) for each measurement For this testing: 1.All devices will be allowed to adjust to ambient room temperature (in the same location) A. Let sit for approximately 5 minutes, or until readings stabilize for 2 mins 2.Oven will be set to a specific F temperature in C A. Will test at 10 data points a. 3.All devices will be transferred in tandem to the oven A. Clock timer will be started B. Once each reached the oven temp time and measurement are recorded C. Devices will be left in 5 more minutes, or until reading plateaus for 2 mins, whichever comes first a. Time to plateau will be recorded, and temperature plateaued at will be recorded

9 4.All devices will be taken out of the oven and placed back in ambient room temperature A. Timer started B. Time for devices to return to their original ambient recording will be recorded C. Time for devices to plateau at ambient room temperature will be recorded. c. Preliminary Results: Figure 3: Preliminary Results of Non-Contact Thermistor Testing. These preliminary results show that all devices being tested have readings within +/- 1 F of each other when measured in the same ambient temperature. The Dollar store axillary thermometer has the fastest response time at seconds, while all other devices take over 3 minutes to stabilize to the ambient temperature. Further testing is needed to determine the accuracy of these results and to determine response time and accuracy for a created circuit, compared to these devices. Addition and Testing of Second Thermistor Circuit: a. Purpose: This will be done once the best thermistor, 100kohm vs 2252ohm is chosen in regard to accuracy and response time. A second voltage divider circuit will be created with the chosen thermistor, and tests will be performed on this new circuit and the circuit of the same resistance previously created. The purpose of this test is to be able to directly compare the measurements and response times of the seemingly same circuits and thermistors to be able to design a method to use both thermistors in tandem for the most accurate measurements. b. Procedure: i. This testing will be conducted in the LTU MEMs laboratory ii. This testing will be repeated multiple times (3-5 times) for each measurement iii. The materials used will be a LCD Screen, Arduino, Laptop, NTC Thermistor x2 (100kohm, 2252 ohm), Resistor x2 (100kohm, 2252 ohm), Wires, and a Bread Board

10 1. The final resistance used will be based on the results of the non-contact thermistor testing 2. 2 circuits, of exactly the same design will be tested iv. Both circuits will be used to take measurements in the same ambient temperature at the same time. 1. This test will be perform exactly as the testing done for the non-contact thermistor testing. It is listed again below: A. All devices will be allowed to adjust to ambient room temperature (in the same location) B. Let sit for approximately 5 minutes, or until readings stabilize for 2 mins C. Oven will be set to a specific F temperature in C a. Will test at 10 data points I. II. All devices will be transferred in tandem to the oven a. Clock timer will be started b. Once each reached the oven temp time and measurement are recorded c. Devices will be left in 5 more minutes, or until reading plateaus for 2 mins, whichever comes first i. Time to plateau will be recorded, and temperature plateaued at will be recorded III. All devices will be taken out of the oven and placed back in ambient room temperature a. Timer started b. Time for devices to return to their original ambient recording will be recorded c. Time for devices to plateau at ambient room temperature will be recorded.

11 Future Adhesive/Casing Tensile/Torsion Testing a. Purpose: To make sure that adhesive and casing are strong enough to withstand normal wear and tear forces and the maximum strength of each silicone mixture. b. Procedure: The exact procedure of this testing will be discussed further with Dr. Nasir or Dr. Meyer. Contact Temperature Testing a. Purpose: The purpose of this test is to confirm the expected accuracy and determine the response of our created ThermaSTAT! Circuit, against the comparable devices, Fever Scout and Temp Traq. This is to make sure that our results are accurate when the ThermaSTAT! Circuit is used for its intended purpose, for the measurement of axillary underarm temperature via adhesive attachment. This is also to determine the accuracy of results and response time when the ThermaSTAT! Circuit and the comparable devices are used for a slightly altered desired use, with the subject s arm lifted allowing for no insulation of heat. b. Procedure: i. For this test the following will be implemented: Human Participant (Sarah/Dana), FeverScout Thermometer, Temptraq Thermometer, ThermaSTAT! Circuit, Arduino, Laptop, Phone, Timer ii. The procedure is as follows: 1. At the same time, each device will be placed next to each other on the upper torso of the test subject, directly underneath the armpit. A. Temperature measurements will be taken while the test subject has their arm in the air. a. Measurements and response time will be recorded when the devices measurement has stabilized and plateaued. B. Separate temperature measurements will also be taken while the subjects arm is in contact with their side. b. Measurements and response time will be recorded when the devices measurement has stabilized and plateaued.

12 C. Before each new measurement all devices will be allowed to stabilize to the ambient room temperature. D. The subject will be asked to stay still for the duration of the measurement. Tasks Completed/Assigned Contributions Test Person Responsible Silicone Ratio Testing for Adhesive/Casing Dana Non-Contact Thermistor Testing Sarah Addition and Testing of Second Thermistor Circuit Sarah Adhesive/Casing Tensile/Torsion Testing Dana Contact Temperature Testing Sarah Updated Bill of Materials

13 Meeting Minutes/Communications with Members and Advisors January 18, 2018 Advisor Meeting Discussed new patch design IRB o We going to test on a subject and it shouldn't hurt the subject. o Write in description that baby will be used for dimensions only and no testing. Design o Make middle small part a different color to show it is more flexible than the sides. Wheatstone bridge o One resistor is thermistor o Separate circuits for both thermistors o Combining thermistors on one circuit makes the circuit more sensitive Calibration o Put thermistor where it needs to go and measure what they give. o Compare the measurements. Average the measurements. Validate Power required to raise the temperature 1 degree in surrounding temperature - dissipation constant Discussing new thermistor option o Go with 2250 Ohm. 0.1 degree C for tolerance. Solid state thermistor? May attach amplifier to raise the output so it can be tested. Practical Interfacing in the Laboratory book. ISBN: Large change in curve means more sensitive measurements. Lower change in curve means less sensitive to change. Stay away from Mega ohms. Could use Voltage Bridge - make sure to use low voltage with amplification. Large voltage will cause thermistor to overheat and be bad for our measurements. Process Control Instrumentation Technology (8th Edition). ISBN: February 14, 2018 Advising Meeting Discussed needing to be more specific on how we re going to test each component Talked about working one step at a time and not bunching several tests together. Discussed using the Smooth-On silicone as the adhesive as an alternative to the TENS electrode adhesive

14 Appendix Figure A1: Top cover of Patch Prototype version 2. Black rectangle is the display screen. Red rectangle is the LED light. Blue circle is the on/off button. The middle textured portion is more flexible than the non-textured sides. Figure A2: Bottom of Patch Prototype version 2. Gold rectangles are the thermistors. Bottom completely covered in adhesive.

15 Figure A3: Top view of Patch Prototype version 3. The component location are drawn in in various colors. Figure A4: Side view of Patch Prototype version 3. The component location are drawn in in various colors. Figure A5: Bottom view of Patch Prototype version 3. The component location are drawn in in various colors.