Chastity Device Health and Safety

My wife, who is quite traditional, is beginning to warm up to the concept of chastity, though she has serious worries regarding health and safety. This concern stems from a casual chat with an ER nurse who shared an anecdote about a patient whose cock ring had to be cut off. I want to give her reassurance, but I haven’t been able to locate any resources that back up my belief that wearing a chastity device correctly is safe for your health. Any recommendations? The Canuck in NJ