I assume you mean one-time a priori to needing them. Otherwise, it's a non-starter; half the purpose of a system like this is to allow the emergency services to

I assume you mean one-time a priori to needing them. Otherwise, it's a non-starter; half the purpose of a system like this is to allow the emergency services to determine if you're unresponsive. Defeats the purpose if you have to authorize the system to tell emergency services that you can't interact with the system.