This week I completed my project for the Enchanted Objects design challenge. It has been funny even if some external activities (namely work and family :-)) didn't allow me to get a more in-depth view of some aspects.
I will now try to assess whether I met the requirements of this challenge
The MagicHat does not publish anything on the Internet. Local connections are encrypted through SSL and access to web UI is protected by user authentication
Accuracy: how well does the proposed solution register the information it is intended to assess?
It's difficult to say: the sensor temperature has an accuracy of 0.1 °C, the earth beat detection algorithm has probably tested and works reliably. The blood pressure detection needs to be verified on a larger number of patients (see below)
Convenience: how easy it will be for non-technical personnel to use ?
Very easy: just power it on!
Cost: how much will it cost? Is it cost effective?
Regarding the hardware and the software, I tried to reduce to the minimum the hardware requirements to run the whole application and I also used standard components that are widely available and very cheap.
The bill of the building materials is very short: plywood, PVC film and screws
However, some optimization could be implemented. In particular the blood pressure measurement method could be changed to make everything happen on the Arduino Yun, thus eliminating the Arduino Mini board. The initial idea was to show the biosignal (which should - at least in my mind- could have been a "wow factor") and to use the biosignal itself to measure both diastolic and systolic pressure. After some experiences, I realized that there are too many factors affecting the amplitude of the biosignal. A better solution could be the approach implemented by balearicdynamics in its meditech. He builds an external board that generates a square wave which frequency matches the number of earth beats per minute. Processing the square wave will be much simpler, freeing enough Arduino Yun's resources to control both servos and mouth's LEDs
Durability: for example, can it withstand everyday life and yet continue to function normally?
Crash tests will are planned after the completion of the demo video :-)