Is Airflow a Factor in Computer Algorithms?

[tech3324]

I'm having a long running discussion with a dive buddy about whether or not airflow (or workload) is used as a factor when computing NDL. Obviously has to be an AI computer for airflow data to be available.

My belief is that airflow can be ignored since the primary factors in tissue saturation are time and depth. Higher airflow won't increase the partial pressure of nitrogen in the blood and so won't affect the saturation calculation.

Is my understanding correct? Do any AI computers use airflow somehow to modify NDL in realtime? Any resources where I can research this topic?

Thank.

 

[tursiops]

The fastest tissue compartment is typically 5 minutes, so it won't see changes in breathing rate unless you can hold your breath for more than 5 minutes! Changes faster than that are just smoothed over.

 

[eponym]

My belief is that airflow can be ignored since the primary factors in tissue saturation are time and depth. Higher airflow won't increase the partial pressure of nitrogen in the blood and so won't affect the saturation calculation. Is my understanding correct?

You are correct that respiration rates per se are not thought to affect on- or off-gassing of inert gasses.
However, my training (esp. my tech) has taught me that increased workloads should encourage you to shorten dive times.
Whether or not there are deco algorithms out there that take that into account is something I'd like to know, too,

 

[JohnN]

You are correct that respiration rates per se are not thought to affect on- or off-gassing of inert gasses.
However, my training (esp. my tech) has taught me that increased workloads should encourage you to shorten dive times.
Whether or not there are deco algorithms out there that take that into account is something I'd like to know, too,

This topic was beaten up pretty badly about 2 years ago. Beaver Divers was quick to point out that the ScubaPro computers could monitor heart rate and use that as an indicator of workload. Unfortunately, there is no empirical evidence to support this. Both photos could produce a heart rate increase

 

[eponym]

This topic was beaten up pretty badly about 2 years ago. Beaver Divers was quick to point out that the ScubaPro computers could monitor heart rate and use that as an indicator of workload. Unfortunately, there is no empirical evidence to support this.

You're right, it was in 2013. In my post above I mentioned workload, not heart rate nor respiration rate. And I agree with you, although I must admit I've not seen any of BD's posts.

Tech3324: I'd suggest that this post by Dr. Deco in that thread is germane to the current discussion. To wit:

Straining and exertion along with bottom time and depth are the major players [in DCS].

 

[knotical]

... I'd suggest that this post by Dr. Deco in that thread is germane to the current discussion. ...

Something’s whack. That link doesn’t lead me to a Dr Deco post, but to a RonR post much later in the thread.

When I try to use the URLs of either one Dr Deco’s two main posts, the same thing happens.

So the alternate suggestion is to look at posts 93 and 119.

 

[eponym]

Something’s whack. That link doesn’t lead me to a Dr Deco post, but to a RonR post much later in the thread.
When I try to use the URLs of either one Dr Deco’s two main posts, the same thing happens.
So the alternate suggestion is to look at posts 93 and 119.

You're right, it's post #93, but clicking on the link in my previous post (and clicking on the link in your quote above) works fine for me, sorry.

Here it is in full:
http://www.scubaboard.com/forums/co...-dci-correlation-post6881835.html#post6881835

Hope this helps,
Bryan

 

[knotical]

Thanks eponym. Maybe the issue is at my end. I have never put anyone an ignore list. I keep getting taken to post #241. I've reported this to HowardE, and I'm sure he'll figure it out.

If someone else either sees the symptom, or successfully links to the Dr Deco post, perhaps you could report it here?

thanks,

 

[Akimbo]

Many dive computers let you manually set an exertion level but gas consumption would not be a reliable indicator. You would have to tell the computers a lot of parameters for it to make anything but a wild guess if your consumption rate is high or not.

 

[Dr Deco]

Hi tech 2234:

Yes, time and depth are the major players. The later governs the pressure of the inert gas [nitrogen] in the capillaries of the tissues. However, not all capillaries of a tissue are open at one time. The number depends on work load for muscle and connective tissues. When tables are tested, the subjects are always made to exercise. A heavy bottom work rate is built into every table.

I have also found that strenuous musculoskeletal activity seems to generate [or enlarge] tissue micronuclei and can increase the risk of DCS. Thus topside activities should be light. Hauling gas tanks around or hiking uphill are bad post-dive topside activities.