When training a dog to perform a task, there must be a "marker" (a sound or word) that tells the dog when he has performed the task correctly.
When the rope is tugged the call is initiated. This could be life saving for someone with PTSD.
Making a phone call
The dog can activate medical panic button from a security or medical alert company, etc. for someone who has lost consciousness or had a seizure, first responder will be notified and be sent to assist the person.
Activating medical panic button to summon first responders