Having built a mission-critical hospital communication system for eight years in my first startup (LiveProcess, which is still going strong) prior to my new startup (Updated.io), I would be remiss if I didn't caution you to go into this space. Convincing execs that you'll be around in a year is but one hurdle you will encounter along the way... there are more stakeholders in the buying process within hospitals' mission-critical communication platforms than you can shake a stick at. Committee after committee, IT obstacle after IT obstacle, entrenched legacy systems that are glued to many stakeholders, nurses, doctors, safety officers, security personnel, and on and on and on... each sets up its own roadblock for you to get into the daily workflow of a hospital. Good luck in this space, but it is NOT for the feint of heart!