Varying Permeability Model

The Varying Permeability Model, Variable Permeability Model or VPM is an algorithm that is used to calculate the decompression stops needed for a particular dive profile. It was developed by D.E. Yount and others for use in professional diving and recreational diving. It was developed to model laboratory observations of bubble formation and growth in both inanimate and in vivo systems exposed to pressure.[1] In 1986, this model was applied by researchers at the University of Hawaii to calculate diving decompression 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. The model depends on the assumptions that different sizes of bubbles exist within the body; that the larger bubbles require less reduction in pressure to begin to grow than smaller ones; and that fewer large bubbles exist than smaller ones. These are used to construct an algorithm that provides decompression schedules designed to allow the larger, growing bubbles to be eliminated before they can cause problems.[2][3]

Bibliography

This bibliography list was compiled by E.B. Maiken and E.C. Baker as reference material for the V-Planner web site in 2002.[4]

Primary Modeling Sources

• 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.
• Yount, D.E.; Hoffman, D.C. (1986). "On the use of a bubble formation model to calculate diving tables". Aviat Space Environ Med. 57 (2): 149–156. ISSN 0095-6562. PMID 3954703.
• 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.). Proceedings of the Reverse Dive Profiles Workshop. Smithsonian Institution, Washington, D.C. pp. 29–61.

VPM Research and Development Sources

• D'Arrigo, J.S. (1978). "Improved method for studying the surface chemistry of bubble formation". Aviat Space Environ Med. 49 (2): 358–361. ISSN 0095-6562. PMID 637789.
• Kunkle, T.D. 1979. Bubble nucleation in supersaturated fluids. Univ. of Hawaii Sea Grant Technical Report UNIHI-SEAGRANT-TR-80-01. Pp. 108.
• Paganelli, C.V.; Strauss, R.H.; Yount, D.E. (1978). "Bubble formation within decompressed hen's eggs". Aviat Space Environ Med. 48 (1): 48–49. ISSN 0095-6562. PMID 831713.
• Strauss, R.H. (1974). "Bubble formation in gelatin: Implications for prevention of decompression sickness". Undersea Biomed. Res. 1 (2): 169–174. ISSN 0093-5387. OCLC 2068005. PMID 4469188. Retrieved 2008-04-16.
• Strauss, R.H.; Kunkle, T.D. (1974). "Isobaric bubble growth: A consequence of altering atmospheric gas". Science. 186 (4162): 443–444. doi:10.1126/science.186.4162.443. ISSN 0193-4511. OCLC 5206521. PMID 4413996.
• Yount, D.E.; Kunkle, T.D. (1975). "Gas nucleation in the vicinity of solid hydrophobic spheres". Journal of Applied Physics. 46 (10): 4484–4486. doi:10.1063/1.321381. ISSN 0021-8979. Archived from the original on 2013-02-24. Retrieved 2008-04-16.
• Yount, D.E.; Strauss, R.H. (1976). "Bubble formation in gelatin: A model for decompression sickness". Journal of Applied Physics. 47 (11): 5081–5089. doi:10.1063/1.322469. ISSN 0021-8979. Archived from the original on 2013-02-23. Retrieved 2008-04-16.
• Yount, D.E.; Kunkle, T.D.; D'Arrigo, J.S.; Ingle, F.W.; Yeung, C.M.; Beckman, E.L. (1977). "Stabilization of gas cavitation nuclei by surface-active compounds". Aviat Space Environ Med. 48 (3): 185–191. ISSN 0095-6562. PMID 856151.
• Yount, D.E. (1979). "Skins of varying permeability: a stabilization mechanism for gas cavitation nuclei". J. Acoust. Soc. Am. 65 (6): 1429–1439. doi:10.1121/1.382930. ISSN 1520-8524.
• Yount, D.E.; Yeung, C.M.; Ingle, F.W. (1979). "Determination of the radii of gas cavitation nuclei by filtering gelatin". J. Acoust. Soc. Am. 65 (6): 1440–1450. doi:10.1121/1.382905. ISSN 1520-8524.
• Yount, D.E. (1979). "Application of a bubble formation model to decompression sickness in rats and humans". Aviat Space Environ Med. 50 (1): 44–50. ISSN 0095-6562. PMID 217330.
• Yount, D.E. 1979. Multiple inert-gas bubble disease: a review of the theory. In: Lambertsen, C.J. and Bornmann, R.C. eds. Isobaric Inert Gas Counterdiffusion Workshop. Undersea Medical Society, Bethesda, 90-125.
• Yount, D.E.; Lally, D.A. (1980). "On the use of oxygen to facilitate decompression". Aviat Space Environ Med. 51 (6): 544–550. ISSN 0095-6562. PMID 6774706.
• Yount, D.E. (1981). "Application of a bubble formation model to decompression sickness in fingerling salmon". Undersea Biomed. Res. 8 (4): 199–208. ISSN 0093-5387. OCLC 2068005. PMID 7324253. Retrieved 2008-04-16.
• Yount, D.E.; Yeung, C.M. (1981). "Bubble formation in supersaturated gelatin: a further investigation of gas cavitation nuclei". J. Acoust. Soc. Am. 69 (3): 702–708. doi:10.1121/1.385567. ISSN 1520-8524.
• Yount, D.E. (1982). "On the evolution, generation, and regeneration of gas cavitation nuclei". J. Acoust. Soc. Am. 71 (6): 1473–1481. doi:10.1121/1.387845. ISSN 1520-8524.
• Yount, D.E.; Hoffman, D.C. (1983). Hoyt, J.W. (ed.). "On the use of a cavitation model to calculate diving tables". Cavitation and Multiphase Flow Forum 1983. New York: American Society of Mechanical Engineers: 65–68. OCLC 232584820.
• Yount, D.E. (1983). "A model for microbubble fission in surfactant solutions". Journal of Colloid and Interface Science. 91 (2): 349–360. doi:10.1016/0021-9797(83)90347-8. ISSN 0021-9797.
• Yount, D.E.; Gillary, E.W.; Hoffman, D.C. (1984). "A microscopic investigation of bubble formation nuclei". J. Acoust. Soc. Am. 76 (5): 1511–1521. doi:10.1121/1.391434. ISSN 1520-8524.
• Yount, D.E. (1997). "On the elastic properties of the interfaces that stabilize gas cavitation nuclei". Journal of Colloid and Interface Science. 193 (1): 50–59. doi:10.1006/jcis.1997.5048. ISSN 0021-9797. PMID 9299088.

VPM Dive Planning Software

• V-Planner: VPM-B & VPM-B/E, VPM-B/FBO.[4]
• MultiDeco: VPM-B & VPM-B/E, VPM-B/FBO, ZHL-B, ZHL-C, GF, and GFS.[5]
• Ultimate Planner: VPM-B, VPM-B/U, VPM-B (Dec-12), VPM-B/U (Dec-12), ZHL-B, ZHL-C, ZHL-D, GF and GF/U.[6]
• DecoPlanner: VPM-B.[7]
• HLPlanner: VPM-B.[8]
• JDeco: VPM-B.[9]
• PalmVPM: VPM.[10]
• DivePlan: VPM.[11]
• Baltic Deco Planner: VPM-B.[12]
• Subsurface: VPM-B.[13]

VPM Dive computers

• V-Planner Live: VPM-B & VPM-B/E.[14]
• MultiDeco-X1: VPM-B & VPM-B/E, VPM-B/FBO, ZHL-C, GF, and GFS.[15]
• MultiDeco-DR5: VPM-B & VPM-B/E, VPM-B/FBO, ZHL-C, GF, and GFS.[16]
• Shearwater Research Predator, Petrel, Perdix and NERD models: GF, VPM-B plus GFS.
• RATIO Computers: iX3M series and iDive (Tech and Reb) series VPM-B and ZHL16-B.[17]
• TDC-3 with MultiDeco-TDC: VPM-B & VPM-B/E, VPM-B/FBO, ZHL-C, GF, and GFS.[18]

See also

• Decompression (diving) – The reduction of ambient pressure on underwater divers after hyperbaric exposure and the elimination of dissolved gases from the diver's tissues
• Reduced gradient bubble model – An algorithm by Bruce Wienke for modelling inert gases leaving the body during decompression in mixed dissolved and bubble phases
• Bühlmann decompression algorithm – Algorithm for modelling of inert gases entering and leaving body tissues in solution as pressure changes

References

1. Yount, DE (1991). "Gelatin, bubbles, and the bends". In: Hans-Jurgen, K; Harper Jr, DE (Eds.) International Pacifica Scientific Diving... 1991. Proceedings of the American Academy of Underwater Sciences Eleventh Annual Scientific Diving Symposium held 25–30 September 1991. University of Hawaii, Honolulu, Hawaii. Retrieved 2011-10-14.
2. Bonuccelli, Corrado (10 March 2004). "Calculating deco schedule with VPM" (PDF). Retrieved 8 June 2016.
3. Watts, Kevin (19 March 2007). "VPM For Dummies". Rebreather World. Retrieved 8 June 2016.
4. "V-Planner dive decompression planning software". HHS Software. Retrieved 8 June 2016.
5. "MultiDeco VPM & VPM-B & VPM-B/E & ZHL GF dive decompression software for technical divers".
6. "Tech Diving Mag - Free online technical diving magazine - Ultimate Planner".
7. "DecoPlanner". Archived from the original on 10 January 2006.
8. "HLPlanner". Archived from the original on 2008-03-15. Retrieved 2008-04-16.
9. "JDeco - Dive Decompression Software for JAVA Mobile Devices (Buhlmann and VPM-B)".
10. "Yahoo! Groups - PalmVPM".
11. Roach, Greg. "DivePlan - Decompression software for SymbianOS".
12. Olsen, Eskil. "baltic deco planner - iPhone deco planning app".
13. Willem Ferguson; et al. "13.2.2. Non-recreational open circuit dives, including decompression". Subsurface 4.5 User Manual. Retrieved 10 November 2016.
14. "V-Planner Live VPM-B, VPM-B/E dive deco computer firmware".
15. "MultiDeco-X1 VPM-B VPM-B/E ZHL-GF dive computer firmware".
16. "MultiDeco-DR5/DRX VPM-B VPM-B/E ZHL-GF dive computer firmware".
17. "Ratio Dive Computers".
18. "Technical Dive Computers TDC-3".

External links

• VPM web site
• VPM development time line