The Use of Venous Gas Emboli to Validate Dive Computers

Rubicon Research Repository/Manakin Repository

The Use of Venous Gas Emboli to Validate Dive Computers

Show full item record


Title: The Use of Venous Gas Emboli to Validate Dive Computers
Author: Blogg, SL; Møllerløkken, A
Abstract: Many decompression models use decompression sickness (DCS) as a measurable endpoint, but often it is not practical to commit the time or money to the large number of dives necessary for validation, nor is it always ethical to provoke DCS. Venous gas emboli (VGE) nearly always accompany DCS, although their presence does not have a direct relationship with clinical symptoms. However, VGE are an accepted indicator of the level of decompression stress that a diver is subject to. There are benefits in using VGE as a predictor for decompression stress. Unlike DCS, which may be misdiagnosed or underreported, the presence of bubbles is an objective measure. As VGE load may be graded, a smaller sample size can be used, as opposed to the endpoint of DCS or no-DCS. Further, the ethical limits of human studies do not have to be reached, as DCS is not the measurable endpoint. This increased sensitivity of measuring VGE allows us to use statistical methods such as the Bayesian approach, a method that employs a priori information, i.e., takes a known outcome sample and combines it with new observations, to produce a risk estimate for DCS. However, the number of dive profiles needed for validation of a dive computer (DC) is infinite. Therefore, a more simple approach is to tailor test to an envelope of the most common profiles used by the target diving population. This method may be used in order to find the optimal DC model for adoption. DCs can be tested against one another, and the DC producing the lowest decompression stress (in terms of VGE produced), then chosen. The DC could then be further validated across a range of other profiles using predictive modeling.
Description: The publication of the Proceedings of the Validation of Dive Computer Workshop is cosponsored by NTNU and the Norwegian Labour Inspection Authority. The symposium was convened by the Baromedical and Environmental Physiology Group of NTNU on August 24, 2011, at the 37th Annual Meeting of the European Underwater and Baromedical Society in Gdansk, Poland.
URI: http://archive.rubicon-foundation.org/10151
Date: 2012

Files in this item

Files Size Format View
VDC_2012_9.pdf 691.2Kb PDF View/Open

This item appears in the following Collection(s)

Show full item record

Browse

My Account