I wrote a Fall Detector app once. When the user is wearing the device (dedicated Android phone), a 'chain' of protection is rendered (3D) which indicates the s

I wrote a Fall Detector app once. When the user is wearing the device (dedicated Android phone), a 'chain' of protection is rendered (3D) which indicates the state of the Fall Detection algorithm. When the algorithm detects a fall, the chain is broken. During the fall, the app indicates whats happening with audio prompts - caretaker alerted, acknolwedged, etc. - and then in order for the app to be changed from "Alert all caretaker" state back to 'ring of safety' mode, the user has to swipe the alert icon. The purpose for this is to ensure that in the case of fall, the app persists until the caretaker acks the app, physically. This proved to be quite workable and fit with multiple users - the 3D "chains" were easy for the frail user to see, while wearing the device - then in case of falls, audio and vibration was used to let the user know help is on its way - and then, to acknowledge, the alert caretaker gets a separate UI that makes accidental de-activation (during an actual fall) impossible.