Digital Electronics in Professional Diving and Hyperbarics

Electronics in Diving

Over the past thirty years digital electronics have seen increasing use in professional diving and hyperbaric applications.

Early computing systems were largely limited to shore-based uses such as physiological calculations for decompression modelling and decompression table development. In operational settings, electronic systems saw some use in communications and gas analysis applications. An early safety-critical control application for which electronics were employed was the automation of self-contained rebreathers which, in professional diving, has been primarily applicable to military operations.

The capability of electronics have increased significantly over the past two decades; a change we have seen in many aspects of our lives. And, most importantly, practices and standards for the development of safety-critical electronics have also improved significantly. These combined improvements in capabilities and safety-critical development have allowed a significant expansion in the application of electronics to diving and hyperbarics.

Decompression Computers

In the 1980s, electronics became small enough to support the development of submersible decompression computers. Today decompression computers are nearly ubiquitous in the recreational diving community. For professional diving, however, the use of decompression computers has been limited for many reasons not the least of which has been the lack of appropriate and verifiable decompression algorithms and certified electronic platforms.

The U.S. Navy has now produced an algorithm suitable for use by some professional divers and suitable for programming into decompression computers for air diving including in-water and surface decompression. This algorithm, the Thalmann Exponential-Linear Decompression Algorithm, has been well documented and may be appropriate for use by some diving organizations – although many organizations may find it to be insufficiently conservative.

The U.S. Navy has used its Thalmann Algorithm as the basis for a prototype decompression computer for surface supplied diving which has provided valuable input into the INTEGRITY Surface Supplied Diving Computer currently under development by ADS.

Saturation Diving

For many years, diving organizations operating on the Norwegian continental shelf have been required to monitor and record the exposure of divers to hyperbaric conditions. Diver Monitoring Systems were developed and installed to record such parameters as diver depth, breathing gas oxygen content and hot water supply temperature. Recorded values were archived in databases.

Around 2005, with diving contracts in the Norwegian Sector of the North Sea in mind, work began at Divex and Draeger to develop a new generation of saturation control systems. Resulting systems provided fully electronic control rooms with operator interaction via electronic displays. Control was primarily via Programmable Logic Controllers; a type of off-the-shelf computer for bespoke industrial control applications. This work resulted in saturation systems onboard DSVs Seven Atlantic, Skandi Arctic and Seven Falcon (formerly Seven Havila) which were well received. A new generation of DSVs is currently under development based on a second generation of this technology and electronic control systems are expected to become increasingly commonplace in saturation diving.

ADS’s INTEGRITY Saturation Chamber Monitoring and Control systems implement the same basic functionality as described above but uses a purpose-built hardware platform to reduce development cost and development risk.

Submarine Rescue Systems

In recent years, many navies have invested heavily in submarine rescue systems which generally include a rescue submersible or capsule and a decompression facility. The NATO Submarine Rescue System includes a decompression facility with an electronic control room . Chamber information is presented on large computer displays and recorded in a database for incident analysis. One major advantage of this electronic system is that plumbing need not be connected between the control room and the chamber containers, reducing setup time for the system and improving response capability.

Submarine rescue decompression systems are essentially air-saturation systems and are suitable for ADS’s INTEGRITY Air Chamber Monitoring and Control systems.

Hyperbaric Medicine

Many manufacturers of chambers for hyperbaric medicine have developed electronic control systems for their chambers. Electronic controls, including automation of treatment profiles and management of electronic records, have proven very effective in medical applications and are increasingly common.

These control systems are often based on an off-the-shelf computer running an operating system such as Windows® XP. Because of this, such systems often do not meet modern standards for the safe use of electronics.

ADS’s Hyperbaric Monitoring and Control System for Hyperbaric Medicine (INTEGRITY Medical Chamber Monitor and Control) systems implement control and data recording functionality on ADS's purpose-built INTEGRITY hardware and software platform in compliance with standards for safety-critical systems.