avpro4

08-29-2007, 03:17

Hey gang, :CI06R376:

My wife finally convinced me I should see somebody about my snoring. Turns out I may have apnea. So in the process of getting tested, I went to a pulmonologist who stuck me in a little closet sized booth and with a fancy medical-grade clothespin on my nose had me breathe in and out both normally and as hard as possible thru a tube in my mouth to measure my resting and working lung volume. While waiting for the results, I mentioned my scuba habit to the technicians, and we discussed how knowing this might be useful in dive planning and gas management.

As it turned out one of the techs remembered a study from his college days that demonstrated a direct correlation between a patient's height and lung volume, and it's very easy to remember: Take the digits corresponding to your height in feet and inches, multiply times 10 and you will have your approximate lung volume in CC's.

Another tech questioned the simplicity of that concept and we decided to see how that formula worked in my case since the computer was just printing out the results of my test. I am 5'6" tall, and my measured average lung volume turned out to be 560 CC's! So according to this formula, a person who's 6'6" would have an average lung volume of 660 cc's.

So I would invite everyone to consider this idea in light of your own dive experience. (Any pulmonologists on the Forum?)

Since Scuba is a pretty relaxing activity (at least once you're under), wouldn't it make sense to time your breathing (say 20 breaths / minute) times your personal average lung volume, divided into the cubic volume of your full tank (converted to CC's), and divide that again by your max or current depth (in atmospheres) to determine in advance how many minutes of gas will be consumed during each phase of your dive?

According to metricconversions.com, 80 cu. ft. equals 2,265,347.736 cu.cm. (ml). So, I leave it to you all to do the arithmetic and offer your opinions as to whether you think this concept: A) Is true based on your personal height and experience beneath the waves, and B) Potentially useful for dive planning and gas management. :smiley23: Remember my test was conducted on dry land as you consider the veracity of the idea.

My wife finally convinced me I should see somebody about my snoring. Turns out I may have apnea. So in the process of getting tested, I went to a pulmonologist who stuck me in a little closet sized booth and with a fancy medical-grade clothespin on my nose had me breathe in and out both normally and as hard as possible thru a tube in my mouth to measure my resting and working lung volume. While waiting for the results, I mentioned my scuba habit to the technicians, and we discussed how knowing this might be useful in dive planning and gas management.

As it turned out one of the techs remembered a study from his college days that demonstrated a direct correlation between a patient's height and lung volume, and it's very easy to remember: Take the digits corresponding to your height in feet and inches, multiply times 10 and you will have your approximate lung volume in CC's.

Another tech questioned the simplicity of that concept and we decided to see how that formula worked in my case since the computer was just printing out the results of my test. I am 5'6" tall, and my measured average lung volume turned out to be 560 CC's! So according to this formula, a person who's 6'6" would have an average lung volume of 660 cc's.

So I would invite everyone to consider this idea in light of your own dive experience. (Any pulmonologists on the Forum?)

Since Scuba is a pretty relaxing activity (at least once you're under), wouldn't it make sense to time your breathing (say 20 breaths / minute) times your personal average lung volume, divided into the cubic volume of your full tank (converted to CC's), and divide that again by your max or current depth (in atmospheres) to determine in advance how many minutes of gas will be consumed during each phase of your dive?

According to metricconversions.com, 80 cu. ft. equals 2,265,347.736 cu.cm. (ml). So, I leave it to you all to do the arithmetic and offer your opinions as to whether you think this concept: A) Is true based on your personal height and experience beneath the waves, and B) Potentially useful for dive planning and gas management. :smiley23: Remember my test was conducted on dry land as you consider the veracity of the idea.