The purpose of the tool is to have an online dive planning tool that combines all the open source tools out there, to build a responsive, fast, efficient and install-free planning tool. You can share dive plans with others, and more importantly, you can script dive plans, to generate profiles difficult or cumbersome to generate manually.
Each of the boxes corresponds to an individual depth and time, and in each box there are three numbers. The real decompression in the center, the prediction of the simple rule in the bottom right, and the error in the top left. A negative number indicates missing decompression using the rule. A positive number indicates a conservative estimate. I also stopped calculating when the error became more than 5 minutes, hence the bottom right of the table is missing. The limitations are starting to appear.
Gue Deco Planner Free
I know that the longest stop will need to be done at 6 m/20 ft, and that the rest of the time should be spent distributed across the 21-9 m/70-30 ft stops. I find that the easiest way is to simply divide my estimate of the total decompression by two, and spend that amount of time on the 6 m/20 ft stop.
I then divide the remainder equally across the intermediate stops. So, a 30 minute decompression would be 3 minutes at 21, 18, 15, 12 and 9 meters (/70, 60, 50, 40, and 30 ft) and then 15 minutes at 6 m/20 ft. A 20 minute decompression would be 2 minute stops and then 10 minutes at the final stop, and a 10 minute decompression would be 1 minute stops and a 5 minute final stop.
Note: The middle number represents predicted total decompression time from Deco Planner; the lower right the estimated decompression using the rule, and the upper left, the difference between the tool (green is greater, red is less)
Three doctors were waiting for me when I arrived at the hyperbaric department at 11 pm. Three doctors? I guessed they were there because they had not seen anyone like me before; it turns out they had rarely seen divers with decompression sickness.
After 39 minutes on the bottom, I began my ascent. The 17 minutes of decompression I had amassed was nothing onerous. After completing all my deco stops, and with my two computers clear, I surfaced and climbed up the ladder back onto the boat, happy. The skipper had taken a photograph of me minutes after I exited the water. There I was, sat on the dive bench, still wearing my rebreather, with a smile on my face.
Even then, studies suggested inner ear decompression sickness (IEDCS) is a low-incidence event. According to one report, IEDCS accounted for approximately 0.005% of cases. Another estimated the rate at close to 3%. One report found most victims were injured following dives which had pushed no-decompression limits, omitted decompression stops, or violated ascent rates. Another found the potential for isolated events to occur randomly during otherwise uneventful deep technical dives that had gone according to plan.
Nothing about an inner ear decompression sickness seemed clear, which revealed that the scientific community had a lot of ideas but not much definite information. I was confused and needed to go in search of answers for myself.
J Appl Physio: Selective vulnerability of the inner ear to decompression sickness in divers with right-to-left shunt: the role of tissue gas supersaturation (2009) by Simon Mitchell and David Doolette
PubMed: Pathophysiology of inner ear decompression sickness: potential role of the persistent foramen ovale (2015) by Simon Mitchell and David Doolette
V-Planner is a decompression program that uses the Varying Permeability Model (VPM-B) for decompression profiles. The VPM-B decompression model is well suited to today's technical diving. The deco profiles will start deeper than traditional models and account for micro bubble growth and keep overall supersaturation lower, and giving a better overall decompression.iPhoneAndroidiPadDive computersMultiDeco-TDC is installed in the Technical Dive Computers TDC-3 model.The dive computer's firmware is aligned perfectly with the MultiDeco planning software. This continuity across the dive platforms, gives a consistent result between the surface planning and the actual dive. Plan your dive, and dive your plan.Windows / Mac / LinuxThe VPM model is the most widely used bubble model by tech divers today.
V-Planner makes plans for Lost deco gas, Turn pressures, Range plans, RB bail outs, watches and warnings. Includes Gas Mixer, Turn pressure formula, Layouts for saving complex dive plans, Graphs, data export, etc.
The Bubble models and similar deep stop profiles, have become the standard fortechnical and deep diving, with many training agencies including bubblemodels into their courses. The VPM bubble model uses math to simulate andmeasure micro bubble growth, and set limits accordingly. The output of abubble model is similar to many established deep practices suchas Pyle Stops, Florida cave practices, DIR, ratio deco plans and others.
In VPM, ascent ceilings are determined on allowable gradients for bubbleformation rather than M-values. These super saturation gradients aredetermined by tracking sets of VPM nuclei (bubble seeds) of a certaininitial critical radius. These are the microscopic physical structures thatstabilize free phase gas and that can grow into full fledged extravascular bubbles whenthe super saturation gradient is sufficient to probe the laplace conditionfor bubble formation.
The Varying Permeability Model was originally developed by Yount and Hoffman in 1986. It was further developed by David Yount, Eric Maiken, and Erik Baker from 1999 to 2001. In 2002, after considerable diver feed back, the model was further developed by Erik Baker, to the current VPM-B model. The V-Planner program was developed by Ross Hemingway, and presents the VPM-B algorithm inside a complete and useful Windows dive decompression program. See also... VaryingPermeability Model (VPM) References
Ratio decompression (usually referred to in abbreviated form as ratio deco) is a technique for calculating decompression schedules for scuba divers engaged in deep diving without using dive tables, decompression software or a dive computer. It is generally taught as part of the "DIR" philosophy of diving promoted by organisations such Global Underwater Explorers (GUE) Innerspace Explorers (ISE) and Unified Team Diving (UTD) at the advanced technical diving level. It is designed for decompression diving executed deeper than standard recreational diving depth limits using trimix as a "bottom mix" breathing gas.
The physiology behind the off-gassing of nitrogen or helium absorbed by the body from breathing gases under pressure has never been definitively established, particularly in relation to the formation of bubbles in the body's tissues,[1] and a number of different algorithms have been developed over the years, based on simplified hypotheses of gas transport and absorption in body tissues, modified to fit empirical data, to predict the rate of off-gassing to reduce the risk of decompression sickness in divers to an acceptable level. However, these models do not describe the individual physiology of the diver accurately: divers have been known to suffer symptomatic decompression sickness whilst diving within the limits of dive tables or dive computers (sometimes referred to as an "undeserved hit"), and divers have exceeded No Decompression Limits but remained asymptomatic.
While Ratio Decompression is not a complete decompression model, it most resembles those of Bühlmann algorithm, and the Varying Permeability Model algorithm, with emphasis on the use of deep stops and gradient factors.[citation needed] It is a type of simplified curve fitting applied to a model decompression profile considered by the author of the model to be acceptable based on experience.
A conventional decompression profile, based on a dissolved gas model algorithm, will result in a diver ascending relatively quickly through shorter deep stops before spending a great deal of time at the shallower stops (resulting in a much sharper angle in the depth/time graph of the ascent profile), ratio deco will allow a diver to dynamically[clarification needed] take a total decompression obligation[clarification needed] for a given dive and create a profile which makes better use[clarification needed] the most effective parts[clarification needed] of the decompression profile, and spends comparatively less time at the less effective stops[clarification needed] (resulting in a much softer[clarification needed][weasel words] curve in the depth/time graph of the ascent profile).[citation needed]
The basis for calculating a decompression schedule using ratio decompression is actually relatively simple (and certainly much simpler than the extremely complicated algorithms used by dive computers). The following represents a slightly simplified summary of the process.[clarification needed] Not all versions of ratio deco use exactly the same procedure.
The starting point is to ascertain the correct ratio (from whence the technique gets its name) of the amount of total decompression time as a ratio to the total bottom time.[2] This ratio is fixed solely by reference to depth. Although on traditional tables the amount of decompression would vary according to time at depth,[3] the basis of the theory that most dives will operate within a range of normalcy[clarification needed] which makes the use of fixed ratios permissible.[clarification needed] Certain depths establish certain ratios; a 1:1 ratio occurs at approximately 150 feet (46 m); a 2:1 ratio occurs at approximately 220 feet (67 m). Between these depths, for each 10 feet (3 m) deeper or shallower than a fixed ratio depth, the diver will then add or subtract a specified number of minutes to their total decompression time.[citation needed] Accordingly, once the diver knows their planned depth and time, they can look up the most proximate ratio, calculate the difference in depths, and add or subtract the appropriate number of minutes from their total bottom time to give a total decompression time. 2ff7e9595c
Comments