Thoughts/Suggestions for New Features

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UCFKnightDiver

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Hey Shearwater,

Recently purchased one of your Perdix AI dive computers and I am loving it so far. One thing I noticed on a dive though is that the Surface Air Consumption/SAC calculation is in PSI/minute. Have y'all ever thought about adding a feature to allow people to put in their cylinder size prior to the dive so that you could get cuft/min? Doing this would allow more usable information about your SAC rate especially as you're doing dives with different tank sizes. For example on a two tank rec charter dive I often use a LP95 on the first dive and an AL80 on the second.

Another thing that came to mind is it would be super interesting for y'all to sponsor some deco research and I would imagine relatively easy. Many people upload their dive profile and data to your cloud based app. It might be interesting to have a short survey people could fill out after their dive with questions related to how they felt post dive (e.g., if someone had skin bends, other DCS symptoms, just felt lousy, etc.) You may only get people that have issues filling out the surveys, but I wonder if you would see some strong correlations between certain gradient factor settings or dive profiles and problems with DCS or even just feeling lousy after your dive (sub clinical DCS maybe).

Just two thoughts. Love diving my Perdix AI computer so far.

- Ryan
 
A. serves no real time benefit as nothing relates to cfm on the active dive... do you have a gauge that reads CF? math for later, and accomplished with various software.

B. impossible to determine any correlation as all off us are not the same, nor are our "perspectives" on how we feel likely the same... far from clinical...
 
A. serves no real time benefit as nothing relates to cfm on the active dive... do you have a gauge that reads CF? math for later, and accomplished with various software.

B. impossible to determine any correlation as all off us are not the same, nor are our "perspectives" on how we feel likely the same... far from clinical...

A. If you think of it like biofeedback it could provide some useful info. Maybe Oh, I notice my SAC rate in cuft/min is a little high on this dive using an AL80 vs. the dive I just did on a steel 95, I wonder why that is. Is it because I'm stressed? Can I do anything to reduce my stress? Is it because I'm working too hard? Can I do anything to reduce my workload? You may not know it was too high if you often dive different size tanks.

B. It's certainly very possible to return a correlation between incidence of DCS or how people feel after a dive reported in a survey and the gradient factors used (multiple correlations potentially between different variables). As you get more data from different people on different dives then those correlations become more valid (statistical power). It's not a clinical experiment where you control for other variables and can "prove" causation but you can get a lot of value out of correlational data. I said correlation but perhaps a better word is association. I believe the appropriate statistical test for the strength of an association between a nominal/categorical variable (assuming that GF is a categorical variable but maybe I've got that wrong) and an ordinal variable (How did you feel on a likert scale from 1 to 5) would be the Point-Biserial Correlation or the Kruskal Wallis test. There's also statistical tests of association for nominal to nominal (Did you have DCS vs. GF used) such as Goodman and Kruskal’s lambda or chi square. Full disclosure, I don't have personal experience using the Kruskal Wallis or Goodman and Kruskal's lambda statistics, though I'm working on a project at work where I may be using them soon.
 
https://www.shearwater.com/products/swift/

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