-Archive from the Spring 2002 semester.
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Doctors are now finding it necessary to test patients experiencing pain or numbness for neurological damage and warm/heat sensitivity by applying hot sensations to their skin. A device that heats up to target temperatures between 38°C and 45°C relatively quickly without frequent charging is preferred.
See our Product Design Specifications for more information.
This project has been a biomedical engineering design project for four consecutive semesters. The web site from last semester is available in the BME design project archives. For more information, see the reports and presentations from last semester.
Our first fully-functional prototype is nearly complete. We have purchased a case and cut the necessary holes to mount the switches, LEDs, and heating element. We have soldered all components onto the printed circuit board, and we are in the process of making a new heating element.
The analog circuitry of our prototype consists of a thermistor, whose resistance is a function of temperature, an op-amp circuit which linearizes the voltage-temperature relationship, and a filter which removes electrical noise. This linearized and filtered output is passed to the microcontroller. The microcontroller used to control heating and the user interface is a Stamp II that reads the temperature and controls the heating and user notification. The program for the Stamp II chip is written in PBASIC and is currently in version 1.0 (see the program history of the code).
Note: Project weeks all begin on Wednesdays.
Week 1 - January 23, 2002 through January 29,
2002
Week 2 - January 30, 2002 through February 5,
2002
Week 3 - February 6, 2002 through February 12,
2002
Week 4 - February 13, 2002 through February 19,
2002
Week 5 - February 20, 2002 through February 26,
2002
Week 6 - February 27, 2002 through March 5, 2002
Week 7 - March 6, 2002 through March 12, 2002
Week 8 - March 13, 2002 through March 19, 2002
Weeks 9 & 10 - March 20, 2002 through April
2, 2002
Week 11 - April 3, 2002 through April 9, 2002
| Week | Reporting Period | Activities |
|---|---|---|
| 1 | 1/23 - 1/29 | Start of new semester. Soldered components to two PCBs. Contacted client. |
| 2 | 1/30 - 2/5 | Found and ordered remaining components for board(power transistor, case). Performed testing of various PCB components. |
| 3 | 2/6 - 2/12 | Redesign of probe head to allow mounting on project case. Ordered remaining components neccesary for first prototype completion. |
| 4 | 2/13 - 2/19 | Met with client. Reviewed and filled out some of the material neccesary for HSC application. |
| 5 | 2/20 - 2/26 | Machined probe heads. Submitted IDR to the WARF. Began computer drawing of prototype. |
| 6 | 2/27 - 3/5 | Ordered remaining hardward neccesary for the construction of our probe. Set up meeting with HSC representative. Completed project box layout. |
| 7 | 3/6 - 3/12 | Machined project box and PVC coupling for probe attachment. |
| 8 | 3/13 - 3/19 | Midsemester presentation. Met with representative from the WARF. Finished machining the project box. Tested thermistors. Began construction of new probe heads. |
| 9 | 3/20 - 3/26 | Began testing of new probe heads. Plotted temperature waveform of our STAMP while operating. Spring Break. |
| 10 | 3/27 - 4/2 | |
| 11 | 4/3 - 4/9 | Worked on new heating routine. Determined could not write journal by deadline. |
| 12 | 4/10 - 4/16 | Worked on a heating routine using changing duty cycles to regulate temperature. Found liquid crystal supplier. Developed way to fasten Ni-Cr wire leads without soldering. |
| 13 | 4/17 - 4/23 | Created new attachment after epoxy found in the threads of the old one. Finished new version of code with threshold control implemented. Attached Ni-Cr leads with modified screws. |
| 14 | 4/24 - 4/30 | Continued construction of the prototype, almost complete. |
| 15 | 5/1 - 5/7 | Finished epoxying switches to project box, worked more on the safety features of the code. |
For questions or concerns regarding the content or layout of the web page, please e-mail the webmaster, Paul Victorey . Other questions about the project can be directed to the project communications leader, Dana Mueller.
If you would like to contact the other members of the team, you may e-mail them: Andrew Hoyord (course improvement), Paul Thottakara (team leader), and Bern Jordan (design courses webmaster).
