Pacific 2012: CASE STUDY 2: Blue Glue connecting divers | ADM Dec 2011 / Jan 2012
Gregor Ferguson | Sydney
One of the CTD projects funded under Round 13 in 2009 came to fruition on Sydney Harbour in late-September. Sydney SME Blue Glue Pty Ltd demonstrated successfully the world’s first system for monitoring and communicating in real time a diver’s vital signs.
The demonstration, at the former Army base at Chowder Bay, saw a team of RAN Clearance Divers demonstrate three separate communications modes in the water in real time, after only a short introduction to the technology.
The divers were fitted with a Polar heartbeat monitor, a modified COTS UWATEC Galileo dive computer, Communications Transmission System (CTS, and Front End Mediation Device (FEMD) both developed by Blue Glue) which tracked their operating depth.
These provided real-time signals back to the demonstration site – a notional ‘mother ship’ – using, first, a fibre optic link from the diver to a float on the surface with an antenna and a 10Mbps wi-fi link to the dive controller. The second mode was a ‘tether’ – a hardwired 100Mbps fibre-optic connection direct from the diver to the dive master back on the ‘ship’. The third was a free dive using a low-power, low probability of intercept 100bps sonar link between the diver and a submerged hydrophone which fed prioritised telemetry and diver messages back to the dive master.
All three modes worked well, telemetry and messages were passed successfully from the divers and fluctuations in their heartbeat and work rate showed up clearly in real time. The dive master’s Dive Control Unit (DCU) is able to integrate the heartbeat, work rate (the difference between active and resting heart rate, a measure of cardiac fitness which is measured separately for each diver), tank pressure, water depth and temperature data and present a picture of the diver’s condition.
The DCU also measures air tank levels, nitrogen and oxygen saturation and body temperate so the dive master can monitor the health of each diver, detect insidious changes early and calculate optimum decompression rates. Nothing else of its kind exists any where in the world so the CTD represents a significant enhancement in diver safety.
Equally important, the divers were also able to use a Kord Pad messaging device to send fixed and free format messages using those same links, thus enhancing the efficiency and productivity of the dive operation. While the purpose of the CTD is to enhance clearance diver safety on routine repair and obstacle clearance operations other applications also exist for the connectivity it demonstrates, not least in the high-risk civilian professional dive sector.