[abstract] A MODEL PREDICTIVE FRAMEWORK FOR DYNAMIC CALCULATION OF OPTIMAL DECOMPRESSION PROFILES

Rubicon Research Repository/Manakin Repository

[abstract] A MODEL PREDICTIVE FRAMEWORK FOR DYNAMIC CALCULATION OF OPTIMAL DECOMPRESSION PROFILES

Show full item record


Title: [abstract] A MODEL PREDICTIVE FRAMEWORK FOR DYNAMIC CALCULATION OF OPTIMAL DECOMPRESSION PROFILES
Author: Gutvik, CR; Brubakk, AO
Abstract: INTRODUCTION: The aim of any decompression procedure is to ascend to the surface as fast as possible without a significant risk of injury. It is generally accepted that gas that comes out of solution is the basis for such risks and a large number of different decompression models have been developed to describe the relationship between gas elimination and the formation of bubbles. Conventional methods claim that adding decompression time improves safety. However, we have recently demonstrated (Brubakk et al UHM 2003;30: 181-93) a significant reduction in bubble formation with a change in decompression profile and a considerable reduction in decompression time. These results indicate that a more optimal profile may exist that can not be found by conventional methods. METHOD: The present paper shows how optimization theory can be of considerable benefit when designing decompression profiles. The optimization variables are chosen to be a set of times to stay on each stop and their corresponding depths. The problem is formulated to minimize the sum of all stop times, hence this framework illustrates a linear basis for the cost function. The constraints of the optimization problem are derived from critical values for the explicit solution of the dynamic model state which are nonlinear. RESULTS: The framework was implemented in MatLab and tested using a conventional tissue compartment model. The method was tested using Buhlmann's ZH-L16 on different sets of dives. The total decompression time was approximately reduced by 8-15percent, just by optimizing the depths of the stops. CONCLUSIONS: This framework shows how the calculation of a decompression profile can be formulated as a standard nonlinear optimization problem. It shows the existence of an optimal profile based on a model predictive response over a future horizon. The test results show that total decompression time can be reduced even with conventional models and critical supersaturation values.
Description: Undersea and Hyperbaric Medical Society, Inc. (http://www.uhms.org )
URI: http://archive.rubicon-foundation.org/1577
Date: 2004

Files in this item

Files Size Format View
abstract.txt 259bytes Text file View/Open

This item appears in the following Collection(s)

  • UHMS Meeting Abstracts
    This is a collection of the published abstracts from the Undersea and Hyperbaric Medical Society (UHMS) annual meetings.

Show full item record

Browse

My Account