Head-Up Display System for Closed Circuit Rebreathers With Antimagnetic Wireless Data Transmission

Abstract

Rebreather divers use LED-based head-up displays (HUD) as a primary display and warning device for the partial pressure of O₂ in the breathing loop. Such devices are usually mounted on the mouthpiece of the rebreather in the field of vision of the diver. LED-based HUDs are simple devices and can be designed so that they are easy to understand but have limited information content. Few alphanumeric or graphical screen-based HUDs have been developed in the past. Connecting such a device to a rebreather requires cable links, which divers dislike, and increases the risk of entanglement. State-of-the-art wireless data transmission uses ultrasonic waves or low-frequency electromagnetic waves; the former is not silent, and the latter achieves only very low data transmission rates of a few bytes per second and does not meet the antimagnetic standards required by military divers. The present paper describes a novel HUD system that incorporates a simple LED-based primary HUD along with an advanced secondary head-up diving computer with a micro organic LED screen. An optical infrared data transmission system is used to transmit all rebreather relevant data from the primary to the secondary device. One prototype of the system was manufactured and successfully tested in the laboratory according to relevant European standards as well as during several dives in fresh and sea water.