Final Project: Specifications

Specification	Value, Value Range, or Quality Relating to Spec	Comments about rationale for specification
Battery life	4 months	Device needs to last the duration of use for the inhaler. Inhalers typically contain 200 dosages (Bailey, 2012). At minimum, 2 sprays per day is equivalent to a minimum battery life of 100 days. We added an additional safety margin to this value.
Button Sensitivity	Button must register only one “use” per canister compression	Button needs to count to relay reliable data about remaining medication to user
Shaking Voltage	Minimum thresholds to qualify as a sufficient shake in the x, y, and z directions is 800 units	The threshold of shaking was defined via experimental testing. Shaking with a voltage greater than 800 was classified as one successful shake. The accelerometer generates a number between 0 and 1023 corresponding to a voltage value between 0V and 5V, so the threshold of 800 corresponds to a voltage of 3.9V measured by the accelerometer.
Number of times shaking	Reach the voltage threshold 12 (each within 500 msec) times to qualify as sufficiently shaken	This is equivalent to six seconds of shaking; the minimum on official Instructions for Use for inhalers often states at least five seconds (PDR Network, 2011).