Diving Thoughts

Recently our dive club has had a question mark about one of the junks we use. Apparently the boatman is not being “very helpful”. Personally I’m very surprised as I’ve always found him extremely helpful, he keeps a good eye out for divers knows where they are, and he always helps loading and unloading tanks. Over the last few years he has also made a lot of effort turning his junk into a suitable diving platform. I think people might be forgetting that when we started using him he knew nothing about divers or diving and I would hate to see us having to go through that same learning curve with someone else.

Anyway thanks to the BBC we may have a solution. In Wisonsin someone who obviously has too much time on his hands has carved a giant pumpkin into a canoe! He’s now planning to paddle it 150 miles in 8 days to raise money for children with special needs. Good luck to him. I’ve never been a big pumpkin fan, so the prospect of spending 8 days in one really doesn’t appeal to me!

You can see the video here.

Not a particularly new story, but thanks to Alex G. for pointing it out to me. Kirill Larin, an assistant professor at the University of Houston in Texas, is attempting to produce a device that could routinely be used on people moving from a high pressure to a low pressure environment, to try and identify the onset of decompression sickness (DCS). His research is in optical coherence tomography (OCT), which uses lasers to make high resolution images of biological tissues.

For any non-divers who have stumbled across this article and haven’t immediately abandoned it for something more interesting, DCS happens when gas such as nitrogen which has been dissolved in body tissues is released and forms bubbles. From a diving perspective, as you descend, the pressure increases which forces more gas to dissolve in the various tissues in your body. As you ascend the surrounding pressure reduces and the gas is released but it tends to group together into microbubbles. Ideally these are expelled through the normal breathing process, but if the pressure reduction happens too quickly then larger bubbles can form which can start to cause problems such as joint pain, neurological problems, skin rashes, burning chest pain. Ultrasound has been used to study these microbubbles, but has a resolution of 80-100 microns, whereas OCT promises images with a resolution of only 2-10 microns, which will detect much smaller microbubbles in the bloodstream and could help diagnose DCS early enough that it can be treated before becoming symptomatic.

The reasearchers’ goal is to produce a portable device that can detect problems in seconds just by shining a light on a person’s skin.

There is an article Popular Mechanics’s website, which mentions possible beneficiaries as divers, but also astronauts and high altitude pilots once they land. Although a pilot landing would face increasing pressure as they descend, not decreasing pressure, so should not be susceptible to DCS unless they’re are other factors involved such as a space capsule or a plane or a flight suit being pressurised to more than 1 bar.

Anyway it will be interesting to see if it is possible to produce a device that is easy to use, portable and cheap enough to start appearing on dive boats. I’m not holding my breath – but then as a diver we’re always taught not to hold our breath!

Ambient Pressure Diving have found problems with some hoses because connector fittings have not been properly crimped. In the photo to the left (from Divernet), the top hose has been crimped correctly and has eight visible flat parts on the metal collar. The one below has not, and the collar is smooth and round.

Products which may have these hoses include low-pressure hoses used on Inspiration, Evolution and Evolution+ rebreathers; the Buddy Blast Hose (air horn end only); second stage regulator hose (second stage end only); and gas connection system (second stage/ADV end only).

There are more details on Divernet.

Apeks is recalling any second stage or octopus for its TX, ATX and XTX regulators that was bought before July and has not had an authorised annual service. Apparently they incorrectly assembled one, which was subsequently sold. If you’ve got one, they recommend that you take it to your nearest Apeks dealer for a visual inspection before you dive with it again. You can see the advisory on the Apeks website.

I’ve just bought one, so I’d better get that checked.