Archive from the Fall 2001 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. This device would be an attachment to the already existing battery operated portable and wall mounted Welch-Allyn ophthalmoscope/otoscope handle.
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 device is currently built and running on a prototype board. We have ordered and just recently received a printed circuit board onto which we will solder our components. We hope to begin testing this early next semester.
The analog circuitry of our prototype reads the temperature from the thermal probe and amplifies and filters the the input to the ADC. The microprocessor 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).
We will all be back to work on the project for Spring 2002!
Note: Project weeks all begin on Thursdays.
| Week | Reporting Period Beginning | Activities |
|---|---|---|
| 1 | September 17 | Assigned roles to team members and met as a group to discuss project goals and tasks. |
| 2 | September 13 | Housecleaning of old project materials. Tested probe for heating characteristics. |
| 3 | September 20 | |
| 4 | September 27 | Investigated a microprocessor kit to use in device. Tested new Welch-Allyn battery to see how powerful it is compared to the old battery. |
| 5 | October 4 | Tested probe prototype for its power requirements at the target temperatures. Continued to learn more about using the microprocessor kit. |
| 6 | October 11 | Prepared mid-semester presentation. Thought about how to use microprocessor. Made CAD drawings of power handle. |
| 7 | October 18 | Mid-semester presentation in class, 10/19. Continued learning about microprocessor. Divided team to work in parallel on separate parts of the project. |
| 8 | October 25 | Continued programming microprocessor. Began design of thermistor circuit. Found Op Amp and ADC that will function with a single supply voltage. Testing components that make up the thermistor circuit. |
| 9 | November 1 | Thermistor circuit design completed, circuit constructed and tested for correct operation. Found probe temperature swings upon cutting and adding power when the temperature rises or falls through each of our 2 target temps. |
| 10 | November 8 | Added filter to the analog circuit to reduce error in voltage conversion. Tested entire prototype, analog and digital parts together. Searched for a way to close a switch upon contact of the probe surface with the patient's skin. |
| 11 | November 15 | Continued testing prototype, updated program code to better deal with errors in operation, and created a program flow chart that tells the function of the code. Investigated the human subjects testing protocol that we will have to supply information for. |
| 12 | November 22 | |
| 13 | November 29 | Ordered parts for prototype. Began PCB design. |
| 14 | December 6 | Finished pcb design and ordered it. |
| 15 | December 13 | Begin prototype construction and demo to the client. Finish final design paper. Final design presentation on 12/14/2001. Attend final design meeting on 12/18/2001. |
For questions or concerns regarding the content or layout of the web page, please e-mail the webmaster, Bern Jordan. Other questions about the project can be directed to the project communications leader, Paul Victorey.
If you would like to contact the other members of the team, you may e-mail them: Andrew Hoyord (the team leader), Paul Thottakara (the course improvement committee member), and Dana Mueller.
