Which sensor to use for 14-day clinical trial study?
we are conducting clinical trials early next month. And we are interested in measuring people's activity (walking, standing, running, being jittery, eating/drinking, driving, ...), their body position (standing, laying, sitting, ...), and we also want to see if we can get their breathing patterns (fast shallow breathing, fast deep breathing, slow shallow breathing, slow deep breathing, ...). The study is running for 14 days and the sensor will continuously be connected (Bluetooth) and steaming to our Android app (our phones support Bluetooth 4.2 and LE. We are using Xiaomi Redmi 4X devices with 3GB Ram and Android 7 with MIUI 9 skin). The sensor should be small since we are asking people to wear it around their chest.
I was informed that accelerometer sensors consume very little power and the MetaMotionC with only accelerometer activated can comfortably last 14 days. But I was informed that the gyroscope consumes a lot of power.
One question is, for the above mentioned purpose, do we need all sensors (accelerometer, gyroscope, magnetometer) activated, if not which ones are required to get the information we need?
Another one is, does does anyone have experience with MetaMotionC or R and longer term bluetooth steaming? How is the battery life?
If the battery lasts for 7 days continuous use on all 9-axis with MetaMotionC I think that would be okay to ask subjects to change the battery once. Else we might have to either not use all 9-axis or we could use MetaMotionR and ask them to plugin the USB cable for a couple hours daily.
Which solution would you suggest we should take? We prefer to get it right the first time around, because it's quiet demanding on the test subjects.
Than you kindly or all replies.