Final Project Week 4

Day 23 (4/22/16)

Today we met with Jim Wice at disability services. We brought our first working prototype to show him, get some feedback, and collect some data. Here is a picture of what we brought to show him:

As you can see, we attached a temporary bell to the end of the servo. Unfortunately, the bell does not work as well as we had hoped, so we will figure out how to fix this problem and work on developing a new bell system for our next prototype.

After we demonstrated our product to Jim he gave us feedback and suggestions. Jim really liked our product. He made a comment that our project was even better than MIT's who had been working on theirs all semester. He had a few questions about the timing of the different warning mechanisms as well as shutting the device off. He wanted us to increase the delay time for the bell mechanism so it wouldn't go off every 10 minutes, but rather every hour (if his temperature had not gone back to the normal range after that time period). We also figured out that he may want to attach the device to the arm of his wheelchair using velcro.

After our demonstration and feedback session, the other group presented their product and got feedback. Once both groups had presented and gotten feedback, we took some data from Jim using our devices. Since Sara's and my project uses a thermistor (a resistor who's resistance varies with temperature), the measurements come as resistances. We determined the corresponding resistances for Jim's ankle at a fairly normal temperature. We did this to get a sense of where we wanted the nominal temperature range to lie on the resistance scale. We attached the thermistor to Jim's ankle and then used the serial port in the arduino program on the laptop to see the varying resistances. We waited until the resistance equilibrated and then recorded the value so that we could personalize the device for Jim's needs.

Overall it was a successful visit with Jim, we got good feedback and data for the next development of our device.

When we got back to the classroom we took more data to determine about how big the range of temperatures (resistances) can be. To do this, we used cups of hot water and ice water. We put the cups one at a time against Sara's ankle to heat up or cool down her skin to simulate changing body temperatures. Once Sara got uncomfortably hot or cold we attached the thermistor and measured the resistance for each of the two extreme conditions. We then shifted this resistance range to be centralized around Jim's nominal temperature, so that the code could be adjusted specifically for Jim.

Towards the end of class, Amy came around to check in with us. She gave us the great suggestion of shrinking down the device to the smallest size as possible and refining all of the parts. We will work next week on condensing the circuit and making the device as presentable and useable as possible.