On May 29, our lesson plan was delivered to 7th grade students at Marin County Middle School through two one-hour classes of 15 students each. It was the last day of a three day lesson plan that was kicked off by Kassie. Overall the lesson was well received, and I tried to insert as much adjacent application (Lie Detector) and pop culture (Wii Fit) references to maintain the students' attention and explain the phenomena.
I led the day's lesson with the IR prototype and introduced the plethysmograph concept by relating it to childhood curiousity of covering the flashlight with a hand. I also digressed and talked about communications applications for IR. The IR prototype lacked an enclosure, so the readings were susceptible to motion artifacts which was an excellent lead into the the high fidelity ECG approach. While students were hooked up to the ECG circuit, the valsava maneuver was an excellent way to demonstrate the physiological effects. The students were really captivated by the signal activity and were exploring ways to induce a higher heart rate such as embarrassment. Here the lie detector concept hooked the entire class; however, it led to a few inappropriate and personal questions but we're dealing with 7th graders after all =)
Worksheets were used the previous day for the manual pulse-feel exercises. This would be a good idea for the devices introduction if more prototypes and XOs were available for the class. For the day we only had 2 ECG prototypes, 1IR prototype, and 2 XOs which was sufficient for explanation purposes but not enough to allow everyone an opportunity to get hands-on with the devices.
We'll be releasing the IR circuit schematic with a BOM soon for those interested in incorporating some biofeedback into their XO/Sugar applications.