- Varying Permeability Model
The Variable Permeability Model or VPM is an
algorithm that is used to calculate thedecompression stop s needed for a particulardive profile . It was developed by D.E. Yount and others for use inprofessional diving andrecreational diving . It was developed to model laboratory observations of bubble formation and growth in both inanimate andin vivo systems exposed to pressure. In1986 , this model was applied by researchers at theUniversity of Hawaii to calculate divingdecompression tables .The VPM presumes that microscopic bubble nuclei always exist in water and tissues that contain water. Any nuclei larger than a specific "critical" size, which is related to the maximum dive depth (exposure
pressure ), will grow upon decompression (when the diver ascends again). The VPM aims to minimize the total volume of these growing bubbles by keeping the external pressure large, and the inspired inert gas partial pressures low during decompression.VPM model description articles:
* [http://www.hhssoftware.com/images/vpm_expl.pdf VPM Explained] by Corrado Bonuccelli. An illustrated, easy to follow description of VPM principles and operation.
* [http://www.rebreatherworld.com/general-and-new-to-rebreather-articles/10721-vpm-for-dummies.html#post103506 VPM for Dummies] by Kevin Watts. This article, published in both English and french in the International Cave Diving Magazine [http://www.plongeesout.com Plongeesout] , provides divers a good working understanding of VPM.References
This reference list was compiled by E.B. Maiken and E.C. Baker as reference material for the [http://www.v-planner.com V-Planner] web site in
2002 .Primary Modeling References
*Yount, D.E. and Hoffman, D.C.
1984 . Decompression theory: A dynamic critical-volume hypothesis. In: Bachrach A.J. and Matzen, M.M. eds. Underwater physiology VIII: Proceedings of the eighth symposium on underwater physiology. Undersea Medical Society, Bethesda, 131-146.
*cite journal |last=Yount |first=D.E. |coauthors=Hoffman, D.C. |title=On the use of a bubble formation model to calculate diving tables. |journal=Aviat Space Environ Med. |volume=57 |issue=2 |pages=149-156 |date=1986 |issn=0095-6562 |pmid=3954703 |accessdate=2008-04-16
*Yount, D.E. and Hoffman, D.C.1989 . On the use of a bubble formation model to calculate nitrogen and helium diving tables. In: Paganelli, C.V. and Farhi, L.E. eds. Physiological functions in special environments. Springer-Verlag, New York, 95-108.
*Yount, D.E., Maiken, E.B., and Baker, E.C.2000 . Implications of the Varying Permeability Model for Reverse Dive Profiles. In: Lang, M.A. and Lehner, C.E. (eds.). [http://archive.rubicon-foundation.org/4244 Proceedings of the Reverse Dive Profiles Workshop.] Smithsonian Institution, Washington, D.C. pp. 29-61.VPM Research and Development References
*cite journal |last=D'Arrigo |first=J.S. |title=Improved method for studying the surface chemistry of bubble formation. |journal=Aviat Space Environ Med. |volume=49 |issue=2 |pages=358-361 |date=
1978 |issn=0095-6562 |pmid=637789 |accessdate=2008-04-16
*Kunkle, T.D.1979 . Bubble nucleation in supersaturated fluids. Univ. of Hawaii Sea Grant Technical Report [http://nsgl.gso.uri.edu/cgi-bin/zgate?present+5828+Default+4+1+F+1.2.840.10003.5.1000.34.1+6 UNIHI-SEAGRANT-TR-80-01] . Pp. 108.
*cite journal |last=Paganelli |first=C.V. |coauthors=Strauss, R.H., and Yount, D.E. |title=Bubble formation within decompressed hen's eggs |journal=Aviat Space Environ Med. |volume=48 |issue=1 |pages=48-49 |date=1978 |issn=0095-6562 |pmid=831713 |accessdate=2008-04-16
*cite journal |last=Strauss |first=R.H. |title=Bubble formation in gelatin: Implications for prevention of decompression sickness |journal=Undersea Biomed. Res. |volume=1 |issue=2 |pages=169-174 |date=1974 |issn=0093-5387 |oclc=2068005 |pmid=4469188 |url=http://archive.rubicon-foundation.org/2676 |accessdate=2008-04-16
*cite journal |last=Strauss |first=R.H. |coauthors=Kunkle, T.D. |title=Isobaric bubble growth: A consequence of altering atmospheric gas |journal=Science |volume=186 |pages=443-444 |date=1974 |issn=0193-4511 |oclc=5206521 |pmid=4413996 |url=http://www.sciencemag.org/cgi/reprint/186/4162/443 |accessdate=2008-04-16
*cite journal |last=Yount |first=D.E. |coauthors=Kunkle, T.D. |title=Gas nucleation in the vicinity of solid hydrophobic spheres |journal=Journal of Applied Physics |volume=46 |pages=4484-4486 |date=1975 |issn=0021-8979 |url=http://link.aip.org/link/?JAPIAU/46/4484/1 |accessdate=2008-04-16
*cite journal |last=Yount |first=D.E. |coauthors=Strauss, R.H. |title=Bubble formation in gelatin: A model for decompression sickness |journal=Journal of Applied Physics |volume=47 |pages=5081-5089 |date=1976 |issn=0021-8979 |url=http://link.aip.org/link/?JAPIAU/47/5081/1 |accessdate=2008-04-16
*cite journal |last=Yount |first=D.E. |coauthors=Kunkle, T.D., D'Arrigo, J.S., Ingle, F.W., Yeung, C.M., and Beckman, E.L. |title=Stabilization of gas cavitation nuclei by surface-active compounds |journal=Aviat Space Environ Med. |volume=48 |issue=3 |pages=185-191 |date=1977 |issn=0095-6562 |pmid=856151 |accessdate=2008-04-16
*cite journal |last=Yount |first=D.E. |title=Skins of varying permeability: a stabilization mechanism for gas cavitation nuclei |journal=J. Acoust. Soc. Am. |volume=65 |pages=1429-1439 |date=1979 |issn=1520-8524 |url=http://scitation.aip.org/vsearch/servlet/VerityServlet?KEY=ASADL&smode=strresults&ver=&possible1zone=article&sort=rel&maxdisp=25&threshold=0&pjournals=ARLOFJ%2CJASMAN%2CNOCOAN%2CSOUCAU%2CPMARCW%2CASASTR&possible1=10.1121%2F1.382930&x=36&y=8 |accessdate=2008-04-16
*cite journal |last=Yount |first=D.E. |coauthors=Yeung, C.M., and Ingle, F.W. |title=Determination of the radii of gas cavitation nuclei by filtering gelatin |journal=J. Acoust. Soc. Am. |volume=65 |pages=1440-1450 |date=1979 |issn=1520-8524 |url=http://scitation.aip.org/vsearch/servlet/VerityServlet?KEY=ASADL&smode=strresults&ver=&possible1zone=article&sort=rel&maxdisp=25&threshold=0&pjournals=ARLOFJ%2CJASMAN%2CNOCOAN%2CSOUCAU%2CPMARCW%2CASASTR&possible1=10.1121%2F1.382905&x=25&y=7 |accessdate=2008-04-16
*cite journal |last=Yount |first=D.E. |title=Application of a bubble formation model to decompression sickness in rats and humans |journal=Aviat Space Environ Med. |volume=50 |issue=1 |pages=44-50 |date=1979 |issn=0095-6562 |pmid=217330 |accessdate=2008-04-16
*Yount, D.E.1979 . Multiple inert-gas bubble disease: a review of the theory. In: Lambertsen, C.J. and Bornmann, R.C. eds. [http://archive.rubicon-foundation.org/4337 Isobaric Inert Gas Counterdiffusion Workshop] . Undersea Medical Society, Bethesda, 90-125.
*cite journal |last=Yount |first=D.E. |coauthors=Lally, D.A. |title=On the use of oxygen to facilitate decompression |journal=Aviat Space Environ Med. |volume=51 |issue=6 |pages=544-550 |date=1980 |issn=0095-6562 |pmid=6774706 |accessdate=2008-04-16
*cite journal |last=Yount |first=D.E. |title=Application of a bubble formation model to decompression sickness in fingerling salmon |journal=Undersea Biomed. Res. |volume=8 |issue=4 |pages=199-208 |date=1981 |issn=0093-5387 |oclc=2068005 |pmid=7324253 |url=http://archive.rubicon-foundation.org/2918 |accessdate=2008-04-16
*cite journal |last=Yount |first=D.E. |coauthors=Yeung, C.M. |title=Bubble formation in supersaturated gelatin: a further investigation of gas cavitation nuclei |journal=J. Acoust. Soc. Am. |volume=69 |pages=702-708 |date=1981 |issn=1520-8524 |url=http://scitation.aip.org/vsearch/servlet/VerityServlet?KEY=ASADL&smode=strresults&ver=&possible1zone=article&sort=rel&maxdisp=25&threshold=0&pjournals=ARLOFJ%2CJASMAN%2CNOCOAN%2CSOUCAU%2CPMARCW%2CASASTR&possible1=10.1121%2F1.385567&x=36&y=12 |accessdate=2008-04-16
*cite journal |last=Yount |first=D.E. |title=On the evolution, generation, and regeneration of gas cavitation nuclei |journal=J. Acoust. Soc. Am. |volume=71 |pages=1473-1481 |date=1982 |issn=1520-8524 |url=http://scitation.aip.org/vsearch/servlet/VerityServlet?KEY=ASADL&smode=strresults&ver=&possible1zone=article&sort=rel&maxdisp=25&threshold=0&pjournals=ARLOFJ%2CJASMAN%2CNOCOAN%2CSOUCAU%2CPMARCW%2CASASTR&possible1=10.1121%2F1.387845&x=21&y=7 |accessdate=2008-04-16
*Yount, D.E. and Hoffman, D.C.1983 . On the use of a cavitation model to calculate diving tables. In: Hoyt, J.W., ed. Cavitation and multiphase flow forum-1983. New York:American Society of Mechanical Engineers , 65-68. ISSN: 9993289434
*cite journal |last=Yount |first=D.E. |title=A model for microbubble fission in surfactant solutions |journal=J. Colloid and Interface Science |volume=91 |pages=349-360 |date=1983 |issn=0021-9797
*cite journal |last=Yount |first=D.E. |coauthors=Gillary, E.W., and Hoffman, D.C. |title=A microscopic investigation of bubble formation nuclei |journal=J. Acoust. Soc. Am. |volume=76 |pages=1511-1521 |date=1984 |issn=1520-8524 |url=http://scitation.aip.org/vsearch/servlet/VerityServlet?KEY=ASADL&smode=strresults&ver=&possible1zone=article&sort=rel&maxdisp=25&threshold=0&pjournals=ARLOFJ%2CJASMAN%2CNOCOAN%2CSOUCAU%2CPMARCW%2CASASTR&possible1=10.1121%2F1.391434&x=39&y=10 |accessdate=2008-04-16
*cite journal |last=Yount |first=D.E. |title=On the elastic properties of the interfaces that stabilize gas cavitation nuclei |journal=J. Colloid and Interface Science |volume=193 |issue=1 |pages=50-59 |date=1997 |issn=0021-9797 |pmid=9299088VPM Dive Planning Software
* [http://www.v-planner.com V-Planner] VPM-B & VPM-B/E
* [http://www.gue.com/decoplanner/ DecoPlanner] VPM-B
* [http://www.hlplanner.com/default.htm HLPlanner] VPM-B
* [http://www.jdeco.de/ JDeco] VPM-B
* [http://groups.yahoo.com/group/palmvpm/ PalmVPM] VPM
* [http://www.diveplan.org/index.html DivePlan] VPMVPM Dive computers
* [http://www.v-plannerlive.com V-Planner Live] VPM-B & VPM-B/E
ee also
*
Reduced Gradient Bubble Model
*Bühlmann tables External links
* [http://www.decompression.org/maiken/VPM/VPM_Program_Site_Map.htm VPM web site]
* [http://www.hhssoftware.com/v-planner/vpmdetail.html VPM development time line]
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