Last week we had two sessions in the Biomechanics Lab, and we have now completed all of the tests that we wanted to do. We did begin to prepare the evaluation report, and we had one meeting in which our team of evaluators did discuss the results of the assessment. The main measurements had been related to impact measurement and heartrate measurement. In addition, we did further measurements to obtain reference data of Cosmin's elaborate device.
We do not yet want to report the details here - this will be in the report. But I want to briefly let you know what we did and what our rationale was.
As has already been pointed out by some of the challengers in the blog here, the measurement methodology for the impact testing was only qualitative. That is, our method of linking the devices with a reference accelerometer (I still have to lookup the exact type of that accelerometer) did inherently have the weakness of a not very strong coupling of the forces. Therefore, the acceleration / impact "felt" by both the device and the reference accelerometer could be significantly different. We did, however, choose this approach (of packaging the device and the reference accelerometer in a padding) so that the devices were not damaged. Most of the prototypes were not designed to withstand actual hard impact forces (except the device "Crown Tools" by Douglas.Wong, which has been packaged into an impact-resistant casing), and it was definitely not our intention to destroy any of the devices.
The heart rate measurement was done the following way: one of our evaluators, Mike, strapped the device on himself and performed a walking / running activity on the treadmill, hereby bringing his pulse up from rest to 160 bpm, and then down again. We wrote then down the measurements from a reference heart rate measurement device and from what the texted Challenge device did report. This evaluation did produce a very quantitative comparison of the heart rate data, which we then used to obtain the score for this task.
Our team has still been in discussion today about how to weight the various aspects of performance and design, and we came to a tentative conclusion. However, we do need one more meeting in which we will finalise this decision, and where we complete our report. Therefore, please be patient until we can publicly report the final conclusion.
As far as I know from the Challenge organisers, next week will be the "official" winner announcement.
In the meantime I have posted a few more pictures from our evaluation activities last week into that Dropbox folder: