1. A computer implemented method for a dispatcher to respond to a 9-1-1 emergency caller regarding a medical emergency of a patient, comprising: providing an emergency medical dispatch protocol including a plurality of interrogatories for a dispatcher to ask a caller to generate an emergency medical dispatch response; initiating a diagnostic tool on a dispatch center computer to determine a vital sign of a patient; the diagnostic tool providing a user interface including a start input to start a timer; the diagnostic tool running the timer in response to the start input; the diagnostic tool terminating the timer; the diagnostic tool determining a vital sign result of the patient based on caller relayed information about the patient and in relation to the timer.