My slut sits in a chair, bound and hooded, with a breathing pipe connected to an air valve which is opened/closed by software. She breathes ONLY when the software permits, and the software doesn't care for her welfare. The safe-word is "RED" which she eventually succumbs to using, but only after over 12 minutes of agony. There are several moments of pure panic, where she considered using the safe word, but then decided trying to endure.