Dear Readers:
That was certainly an interesting exchange on the Techdiver board. It does illustrate that decompression has, as with many things, differing viewpoints.
I would offer only a few comments that are quite general. These are not in reply to any thing specifically but rather are general comments that I feel are necessary to avoid confusion in the diving community with respect to the Dr Deco column.
DIFFERENCES IN INTERPRETATION.
[sp] All science at the daily, working level has differences in the interpretation of data. What we read in textbooks as science is that material that is tried and true and upon which virtually all scientists would agree. This is not what the working scientist does. Science is a body contact sport and not a task of memorizing a set of facts. I try to impart that concept to students when speaking to them.
[sp] If science were rote memorization, it would not be fun. It is the constant, daily give and take. It is the inevitable battles. This demonstrates that differences in opinion will exist. All professional scientists are willing to accept that. The readers of this FORUM must also bear in mind that much of the questions asked are on the edge of technology and/or physiology and some of this material will be my opinion. I have tried to indicate when it was mostly my opinion - - not only in fairness, but because I know that my scientific colleagues read this series.
RESEARCH FUNDING
[sp]Many times readers wish to know why something has not been studied. Very often, it is simply a matter of research funding. Most are not aware of the actual mechanics of the research funding process and do not understand how this is done. Not every valid question will be studied because there is simply NOT ENOUGH MONEY TO ANSWER AND INVESTIGATE EVERYTHING.
RESEARCH FUNDING IN DECOMPRESSION
[sp]There is relatively little money for decompression research. Recreational diving DCS is not high up on the list compared to AIDS, heart attack, cancer and stroke. Some programs directed towards specific questions are run by the Navy and Air Force, and some by NASA in the United States. The Canadians and the British have a program. The Germans did, but I do not believe it is very active today. Some diving research is performed in France and Norway.
[sp] NASA does not fund studies related to recreational scuba diving. NASA works only with respect to decompression problems in space with its astronauts. By most standards, these programs could be larger. However, all scientists will tell you that their programs should be bigger.
DECOMPRESSION SICKNESS LABORATORY WORK
[sp] It is not possible to study all questions concerning decompression sickness, since sometimes you can get into serious difficulties and a test subject could become injured. As is true with many studies, I have participated in them before asking others to be a subject. This has been true for several decades with me personally, and I am not alone in this aspect.
[sp]However, personal opinion does not satisfy legal people when risk is concerned. This is because most scientists are personally immune from lawsuits since they are the employees of a larger organization. The parent organization is liable for the scientists mistakes, and therefore many individuals will watch what is done.
[sp] Neurological DCS is a big question and many interesting studies COULD be done but will not because this is dangerous to the test subject. Thus, when I state that bending over to pick up a scuba tank will quite possibly cause nucleation in the spinal cord, I am speaking from a theoretical perspective based on observations in muscle tissue with Doppler bubble detectors. Have I ever had a series of twenty people become supersaturated and then had them flex their spinal column several times to see if I can induce neurologic DCS? No. And I doubt that I will ever have the chance to perform such a study. Furthermore, no one should volunteer for such a study. I believe that I am dispensing good advice based on extrapolation of scientific knowledge - - but some things cannot be tried in a laboratory.
FEEDBACK FROM READERS
[sp]It is interesting when a reader comments that such straining did precipitate a case of neurological DCS. While that does not confirm the theory, after several years, one hears enough stories to believe that you are one the right track. This feedback from the field in invaluable when you know that it can never be corroborated in the laboratory for medico legal reasons.
[sp] Without the effort to produce this FORUM, I would not receive the replies that I do. Likewise, with the Decompression Physiology class. One gets new feedback all of the time. I receive this as payment from all of the effort.
WKPP
[sp]This group, from what I know of them from the web site, is involved in diving, and it has apparently developed a very good record of accomplishment with respect to diving and decompression. They have a specialized niche in the world, as does NASA. No one will benefit directly from NASA procedures for EVA unless you are an astronaut performing extravehicular activity. Possible WKPP procedures are similarly specialized. Likewise, what is good for one group may not be of use to another and vice verse. We need take what is useful and set the rest aside possibly for another day.
[sp]None of what NASA does is of value to recreational divers. It is only through my interpretation of that activity with respect to scuba divers that something useful will result. If some of this is known to others, that is fine. If my interpretations are not thought to be correct, that is also possible. Not all of my interpretations are agreed upon by all scientists here at NASA in barophysiological work. Why should the rest of the world be different. I do stand on my thirty-year record of accomplishment, however.
CODA
[sp]I trust that this material is of benefit to recreational divers, that is, the tax payers of the United States whose taxes made this possible. While not everyone believes that every government project is of value, I believe that most are happy to hear that they are directly getting something for their tax dollar in space. [Bear in mind also that I do this as a private citizen and not acting as an employee of NASA. I trust that everyone knows that this is a site of ScubaSource and not an official NASA site.]
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Michael R. Powell, MS, PhD, aka Dr Deco
