Dive Profile Analyzer?

[scubadada]

Hi @baptizo

Sorry to hear about your episode of DCS. Have you already called DAN to discuss the episode and your current state?

I'm assuming your DCS occurred after your second dive of the third day, is that correct? Was your ascent from that dive normal, <30 ft/min, and did you do a safety stop? If you don't mind, what were the symptoms and signs of your episode? Was your hyperbaric treatment a normal Navy table 6 or similar? Did all of your symptoms and signs resolve after the HBO treatment or did some remain. How long has it been since the episode now? You say you are not feeling well, does this seem like residual from the DCS or different?

As you have discovered from your reading, Cressi RGBM is one of the most conservative of the decompression algorithms, including the factory set SF0. I would imagine that Cressi RGBM would fall somewhere between a Buhlmann GF high of 75-85, maybe you will see from your experience with Subsurface.

Your SB profile states you joined 10 years ago but only lists 0-24 dives, is this right? Do you have previous dives or series of dives that look like what you did in Cozumel?

Best of luck in fully recovering from this event. Thanks for sharing, we all look forward to learning more about our diving.

 

[Duke Dive Medicine]

Last week while in Cozumel, I suffered a case of DCS. I was treated with one round in the chamber. I stayed additional days before flying home. I am still not feeling well.

I dove 3 consecutive days with 2-tank morning dives with an hour in between.
I had my Cressi computer on each dive.

After getting home and uploading computer data, I saw that I did run the NDL clock down into the single digits several times.

I have been reading for a week now (and learning) about the different algorithms.

My question is:
Is there some type of software that I can input the Depth and Time recording into that would compare output of the different algorithms? (I have Subsurface and a trial copy of DecoPlanner (gue) already.)

For example. My cressi uses the RGBM (and I know I pushed it the edge), but what would a Shearwater running ZH-L16 shown I exceeded the NDL?

I am not interested in all the thoughts concerning the different algorithms. None of them are an exact science. I also know there are no sure things.

But I did get sick, and I do have my dive data. And I would like to compare the different models.

Just trying to figure out what happened. Thanks for yalls help.

As you alluded to, the risk of DCS in diving is not zero, regardless of whether you adhere to a decompression algorithm. Also, decompression algorithms are not iso-risk - probability of DCS increases with increased depth and bottom time, at least in the ones that have been studied and compared using probabilistic modeling. There's a tendency to try to "blame" DCS on something, when the reality is that people sometimes get decompression sickness for reasons that we're unable to understand. Heavy work on the bottom and being cold on decompression are risk factors for DCS, and there is some evidence that dehydration can increase risk as well.

Absent specific information about your dive profiles and symptoms, the recommendations for PFO testing are premature.

Best regards,
DDM

 

[dmaziuk]

...

But I did get sick, and I do have my dive data. And I would like to compare the different models.

Just trying to figure out what happened. Thanks for yalls help.

If you got DCS without bending your Cressi, I'm fairly certain that comparing algorithms will not tell you anything. Other than you shouldn't have gotten bent. The algorithms know nothing about you, they only estimate the chance of clinical DCS symptoms based on a mix of theory and statistics.

I don't think even DSAT would've gotten a diver bent after 3 days of 2 dives/day w/ an hour's SI. They did bend one of their 4 test divers after day 2 of the trials, but they were running 6 dives/day (over 11 hours so probably less that 1 hr SIs) to get there.

The only thing I can think of that might be of interest is this: SAUL – A PROBABILISTIC DIVE PLANNER | Modern Decompression -- but I don't think he has the opton for repetitive dives. Edit: not that it matters much because with 2 morning dives/day, you'd practically "clean" by the next morning by about every model other than RGBM that your Cressi is using.

 

[scubadada]

...The only thing I can think of that might be of interest is this: SAUL – A PROBABILISTIC DIVE PLANNER | Modern Decompression -- but I don't think he has the opton for repetitive dives.,,

I have been following the SAUL probabilistic decompression algorithm since 2010, when I first read about it in DAN's Alert Diver and then, a little later, in Diver Magazine. These articles are linked on the Modern Decompression website. I think many of you would be interested in exploring the probabilistic dive planner linked in the @dmaziuk post. The algorithm has been discussed a few times on SB but remains little known. The SAUL algorithm includes a 3 min safety stop at 15 ft.

Here is a table showing the NDLs for DSAT, PZ+, and Buhlmann and the associated risk of DCS on a first clean dive on 32% nitrox. The riskiest dive in the table, 110 ft for 25 min using DSAT has a probability of DCS of 0.173% or 1/578 dives.

There is a very interesting blog entry on the website that discusses the probability of one episode of DCS if doing multiple dives with a known probability of DCS The Significance of DCS Probability on a Single Dive Profile | Modern Decompression Using the 110 foot dive for 25 min on 32% from above, you might expect one episode of DCS somewhere in excess of 1000 identical dives and less than 10,000 dives, closer to the latter. The probabilities in the graph below are not in %, use 0.00173 in the comparison.

I have been using SurfGF since I bought my Shearwater Teric in May 2019. I used to do a variant of an adaptive safety stop or padded my deco stop. Now, there is no guesswork, I have not surfaced above a GF in the low 80s since, my average dive is in the 50s. Personally, I like knowing the information from the SAUL algorithm, maybe you will too

 

[dmaziuk]

We had a DM on one of our trips, Curacao I think, who looked like ex-Navy (and had a Cochran) though I didn't ask her to confirm. She said when she got bent, the chamber doc asked for her dive count and after hearing the answer, said this was "just her time" and trying to figure out the whys and the blames will get her nothing except mental health problems.

 

[scubadada]

We had a DM on one of our trips, Curacao I think, who looked like ex-Navy (and had a Cochran) though I didn't ask her to confirm. She said when she got bent, the chamber doc asked for her dive count and after hearing the answer, said this was "just her time" and trying to figure out the whys and the blames will get her nothing except mental health problems.

I dived a Cochran computer as a backup to Oceanic computers running DSAT for about 5 years. It is the only computer I've dived that is more liberal than DSAT.

 

[tursiops]

I dived a Cochran computer as a backup to Oceanic computers running DSAT for about 5 years. It is the only computer I've dived that is more liberal than DSAT.

Cochran was an interesting computer. I've still got the software somewhere on my desktop....
See They Helped Foment a Dive Computing Revolution: RIP Cochran Undersea Technology (1986-2020)

 

[scubadada]

Cochrane was an interesting computer. I've still got the software somewhere on my desktop....
See They Helped Foment a Dive Computing Revolution: RIP Cochran Undersea Technology (1986-2020)

Hi @tursiops

Thanks for the article, I had not read it for a while.

I no longer have the Cochran software on my current computer, but I do have it on a mini disk down in Florida. I think it was called Analyst. It was a good, reliable application. It allowed me to send several hundred dives to DAN Project Dive Exploration that ran from 1995-2008.

I still have my Cochran Computer, bought in 2005, and it still works beautifully. I have not dived it for some time but I have loaned it out a few times. It matches DSAT and GF high of 95 that I dive on my computers quite well.

I encourage folks read the article you provided. Cochran was ahead or its time, the good old days.

 

[Capt. Mitch]

Last week while in Cozumel, I suffered a case of DCS. I was treated with one round in the chamber. I stayed additional days before flying home. I am still not feeling well.

I dove 3 consecutive days with 2-tank morning dives with an hour in between.
I had my Cressi computer on each dive.

After getting home and uploading computer data, I saw that I did run the NDL clock down into the single digits several times.

I have been reading for a week now (and learning) about the different algorithms.

My question is:
Is there some type of software that I can input the Depth and Time recording into that would compare output of the different algorithms? (I have Subsurface and a trial copy of DecoPlanner (gue) already.)

For example. My cressi uses the RGBM (and I know I pushed it the edge), but what would a Shearwater running ZH-L16 shown I exceeded the NDL?

I am not interested in all the thoughts concerning the different algorithms. None of them are an exact science. I also know there are no sure things.

But I did get sick, and I do have my dive data. And I would like to compare the different models.

Just trying to figure out what happened. Thanks for yalls help.

Its foolish to bet your life on a dive computer. You must always check your dive profile against established tables.

 

[Puppeteer]

If you haven't already done so, you can upload your dive profiles to DSG3 | Login and they give you a bit of a measure of how risky your dive is (and they take into account your surface interval)