Skin bends...

[Pebbles Photo]

Have had what appears to be skin bends a few times now, and would like to find : Either a person/company that will rent a Doppler device to a diver to use after some scuba dives at various depths and durations and safety stop durations....or, some links to doppler devices good for this purpose, that would be affordable to a diver....say for $500 or so... I have seen some portable doppler devices for sale on doing Google searches, but they do not appear to be specific for the bubbling in divers, and maybe more for use on pregnant women, or for DVT, or other issues....and it is not clear to me whether the manner of reporting or audio indications with each device would differ for use in scuba.... Any suggestions?

 

[caruso]

I suggest you get evaluated to rule out a PFO.

 

[michael-fisch]

Ebay has good and dirt cheap 8mhz dopplers. I bought mine new for less than $100 back about 10 years ago, and they have to be cheaper now. Make sure to buy with an 8Mhz head, lower frequency heads penetrate way too deep.
Familiarize yourself with the speed of bubbles in the various Spencer grades, and try to stay at Grade 2 or lower.

Michael

 

[Wookie]

I have watched a number of DAN/Duke studies where PhDs and med students took doppler readings on divers following their dives. Getting it right is very difficult, and doing it on yourself would be near impossible, IMO, to obtain any meaningful data.

 

[michael-fisch]

This is the doppler that I bought back then, and it works very well.
Vascular Sonotrax Ultrasonic Pocket Doppler W/ 8 MHz & Batteries, Case, Gel | eBay

Find the carotid vein on the side of your neck and you will hear blood flowing by, if there are bubbles they are easy to hear - but if you aren't focused on the vein you don't hear anything.

Michael

 

[Wookie]

This is the doppler that I bought back then, and it works very well.
Vascular Sonotrax Ultrasonic Pocket Doppler W/ 8 MHz & Batteries, Case, Gel | eBay

Find the carotid vein on the side of your neck and you will hear blood flowing by, if there are bubbles they are easy to hear - but if you aren't focused on the vein you don't hear anything.

Michael

Cool. That is probably miles easier than what the DAN/Duke folks were doing, which was looking at the left ventricle of the heart. Bubbles are cool.

 

[tech_diver]

Is a DIY doppler really a thing?

My understanding was that there was a lot to getting consistent and accurate doppler scores. Isn't there some level of 'interpretation' when listening for bubble clicks?

I'm not sure how DIY dopplers would be used except in the context of some DCS study. Detecting bubbles doesn't necessarily mean you are bending.

It would be interesting to imagine such a device in a first aid kit or connected to a dive computer but I don't know if that could be done realistically.

 

[michael-fisch]

If you don't have bubbles 45 minutes after a dive, you either did your dive in a 10' swimming pool or you are doing way too much deco/safety stop. The trick is to have a light but steady stream of bubbles that are going slow enough to easly be able to count them. If you have a steady stream of bubbles that you can no longer count, you overdid things and it's time to start breathing O2 while others start arranging fastest travel to a working chamber. With serious DCS you only have a short window of opportunity to heal completely and any wait over 6 hours will probably preclude an ideal outcome.
Been there, done that, and my balance is still slowly improving 4 years later.

Michael

 

[Duke Dive Medicine]

Have had what appears to be skin bends a few times now, and would like to find : Either a person/company that will rent a Doppler device to a diver to use after some scuba dives at various depths and durations and safety stop durations....or, some links to doppler devices good for this purpose, that would be affordable to a diver....say for $500 or so... I have seen some portable doppler devices for sale on doing Google searches, but they do not appear to be specific for the bubbling in divers, and maybe more for use on pregnant women, or for DVT, or other issues....and it is not clear to me whether the manner of reporting or audio indications with each device would differ for use in scuba.... Any suggestions?

Hi @Pebbles Photo ,

First, I love the headgear. Looks a bit small to keep but makes for a nice conversation starter

What type of skin bends are you getting? If it looks like this

or this

it could be related to PFO, though if it's happened more than once it would increase the index of suspicion. From your post I assume that you are familiar with the literature on venous gas emboli, arterialization of those, and their relationship to some DCS symptoms. From a practical standpoint, using a Doppler ultrasound on yourself might be a little awkward, but it could be done if you're a skilled operator. In the past, for audio only, we've used the Techno Scientific DBM9008 and DBM9610. I just did a quick search for the cost on those and came up blank. You might query DAN as to what kind they use if you're just looking for audio. I would second @caruso 's recommendation that you be evaluated for PFO.

Best regards,
DDM

 

[Germie]

And from the Wetnotes magazine of october 2018 (article only in german and not online).
They said no testing on a first case needed, maybe after more cases needed, and even when a pfo found: no change in diving needed, just take the oxygen at surface. Closing is in most times not needed. Even technical diving is NO problem they wrote with pfo. Closing is just something to think about if even with surface oxygen still problems occur. So I would try surface oxygen first. Doesn't cost a lot. If this works, you have the solution.