Thalmann Algorithm Parameter Sets for Support of Constant 1.3 ATM PO2 HE-O2 Diving to 300 FSW
Abstract
The current Navy Dive Computer (NDC) and Navy Dive Planner (NDP) can only support 1.3 atm PO2 He-O2 diving to a maximum depth of 200 feet of sea water (fsw), not the 300 fsw maximum depth supported by the 1.3 atm PO2 He-O2 Decompression Tables in the U.S. Navy Diving Manual. In these tables, schedules for depths deeper than 200 fsw are computed using the LEM-he8n25 probabilistic decompression model with a target probability of decompression sickness (PDCS) of 2.3 %. Probabilistic decompression algorithms are too computationally expensive to be implemented in a diver-worn decompression computer (dive computer) such as the NDC. Previously, the XVal-He-4 and XVal-He-4B parameterizations of the Thalmann Algorithm were developed to emulate the LEM-he8n25 2.3 % PDCS 1.3 atm PO2 He-O2 decompression schedules for depths of 200 fsw and shallower. The Thalmann Algorithm is the computationally inexpensive deterministic decompression algorithm currently implemented in the NDC and NDP. This work refined the technique used to generate the XVal-He-4 and XVal-He-4B parameters and used the refined technique to produce new parameter sets. With the new parameter sets XVal-He-9_023, XVal-He-9_040, and XVal-He-9_050, the Thalmann Algorithm can compute decompression schedules for undersea operations to depths up to 300 fsw and with PDCS near 2.3 %, 4 %, or 5 %, respectively. The Thalmann Algorithm with these parameter sets can be implemented in currently availabledive computer hardware.
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 31, 2018
- Accession Number
- AD1215316
Entities
People
- David J. Doolette
- F. G. Murphy
- Wayne A. Gerth
Organizations
- United States Navy Experimental Diving Unit