A controlled ascent that gives the body time to safely off-gas inerts will significantly reduce the probability of you ending up in a recompression chamber but there are no guarantees. Modern dive computers are very smart devices, but they operate on a generic model - they’re not tuned to your own unique physiology. Many factors affect how efficiently your body off-gases – fitness, BMI, age, hydration levels and so on – but your computer won’t account for any of these. Even those divers that cut their own deco schedules rarely adjust profiles to mitigate for variations in their own physiology.

Imagine if you could fine tune your dive computer to reflect your physiology. France-based Azoth Systems believe they may have the answer – the O’Dive personal ultrasound doppler. Combined with a sophisticated app that runs on both iPhone and Android devices, this clever little puck-sized sensor allows you to capture post-dive bubble measurements from your own blood stream in a non-intrusive way. You don’t need a PhD to analyse the results either – Azoth’s own servers do all the heavy number crunching and return the results to your smart phone in an easy to digest form.

Correct positioning of the O’Dive sensor does take some practice but the app thankfully provides plenty of guidance. Unlike precordial dopplers used by research scientists, O’Dive is a subclavian sensor – that is, it measures bubbles via the subclavian veins that lie just below the collar bone. Using this type of sensor does have its benefits – the raised collar bone makes positioning the sensor relatively easy and measuring here gives a cleaner signal with the sensor not having to deal with the noise generated by the heart’s own valves.

Assuming that the results you received back from Azoth raised an eyebrow, O’Dive gives you the tools to improve the safety and efficiency of your decompression profile. Built into the O’Dive app is a sophisticated ‘simulator’ that lets you view the effect of tweaking specific factors of your dive – the gases you breathed, the gradient factor used, or the setpoint of your CCR controller at depth and so on.

By adjusting the onscreen sliders, the effect of these changes will be displayed in real time with the reduction in both the severity and bubble values and the ‘Quality Index’ of the dive displayed as a percentage. An estimated ‘safety multiplier’ is also displayed which represents the increase in safety compared to the original profile.

Armed with the insight you’ve gained from tweaking your profile with the simulator, the theory is that you incorporate these changes into your profile and take them diving. But how well does it work in reality? Regular readers will already know Phil Short – he’s arguably one of the world’s leading deep trimix wreck and cave divers and has featured in the magazine on many occasions.

With years of experience diving at expedition level in some of the world’s most inhospitable regions, Phil’s just the sort of indestructible ‘lab rat’ you need to thoroughly evaluate the effectiveness of something like the O’Dive. Phil has used the device on a number of recent projects including high workload dives on a WW2 B-17 bomber aircraft laying at a depth of 70 metres in Croatia and – most recently – exploration at depths of up to 130 metres in the Langbans Mine in Sweden. We asked Phil for his take on how the O’Dive had performed on these projects.

“What I learnt was that my profiles needed reshaping rather than lengthening or shortening and that it would be prudent to always extend my last stop with the addition of a safety stop once my prescribed deco had cleared.”

But what benefit would the average diver gain from using O’Dive? Again, we put this to Phil. “I’ve logged over 6000 dives in 30 years as a diver and to date, had no incidence of decompression illness. I would like to maintain that track record by monitoring and evolving my dive profiles with all available advice and methods long into my diving future. Right now, the O’Dive is a significant advance in personal dive planning that will help me meet that goal.”

Praise indeed but perhaps the most exciting aspect of O’Dive is something far less tangible. O’Dive gives us an enticing insight into the potential of this technology and what it could mean for diving moving forward. As the technology reduces in size still further, could we see a future where divers wear sensors during a dive that communicate real-time physiological data to their dive computers? Imagine a future where your computer is generating a dive profile specific to your body. Dehydrated? Feeling the cold? Your computer could compensate for these factors. Now that is truly exciting and could represent a seismic shift in diver safety. The future is wearables and you heard it here first folks.