I would like to export raw accelerometer (and possibly other sensor) data from a wearable device (i.e. not just processed data such as number of steps and velocity, but x/y/z acceleration data and possibly others). Thought this would be technically easy, but failed to find a suitable device so far when searching the internet and writing to manufacturers' customer support (so far, no or negative answers). Does someone have experience with that and can possibly name a model from which this is possible?
Purpose is to monitor fitness and physical fatigue in disabled people with certain movement disorder diseases, where we are interested e.g. how "economical" they walk, not just how much, since motivation becomes a problem once every step becomes more and more difficult. For an academic project, we are looking for free (open) solutions that do not rely on expensive extra fees or contracts/goodwill of a company in addition to buying the devices.