Albi Salm

SubMarineConsulting · R & D: www.SMC-de.com

For the annual meeting of the OeGTH 12/2022 in Vienna we presented: Gradient Factors: on the rise? We discussed: Idea & function of Gradient Factors (GF), topical implementations, implications for dive planning and a short trip into history. As well we offered food for thought and further references.

Trimix - compact! is a little manual for practical diving with ternary gas-mixtures that is: oxygen, helium and nitrogen. In a concise way all these topics are covered which you normally miss in standard Trimix manuals. Many references and hints for further reading are following each chapter. The rationale behind this booklet is what once DAN, the...

We identified 5 physiological key-parameters influencing perfusion i.e.: inertgas-saturation /-desaturation. Subsequently, the half-times of the mono-exponential functions for inertgas saturation/-desaturation of the theoretical (tissue-)compartments are influenced in turn, or, as is the case for R q , the ventilation, and, as such, the composition...

This communication is on the implementation of a tool to calculate the new oxygen exposure indices, i.e. the indices concerning the oxygen toxicity (-OT) for the central nervous system (CNS-) and the whole body, the pulmonary (P-)system, pls. cf. ref. [1] & [4] and all the references therein. It is not intendend to discuss the scientific backgroun...

Here in Part III, we take a look back and follow the development of a couple of european air diving tables for recreational diving. This historical path is mirrored in the development of the first european diver-carried computers. We give samples of these tables along our ubiquitous test profile: 42 m, 25 min on air. We close the presentation with...

Digging up the past (Part II): a controlled dry, bounce dive on air to 51 m; 10 years later … (2019). Abstract: 10 years later, we are still in the deco-chamber …, pls. cf. ref. [1]; but now with other computers and/or new firmware and lots of divers (ca. 10 to 14 per ride), having fun & narcosis. Introduction: 4 photos from the background story....

Here, in Part I, we present the results of a dry, repetitive dive on air in a decompression chamber from June 2009 with 9 dive computers, two of them the OCEANIC® OC1, a dual-algorithm wrist watch-format dive computer. The dive-profiles (50 m, 52 min; SI = 30 min; 36 m, 42 min) were designed to challenge these two algorithms. There were no cases of...

Instruction manuals are mandatory for most diving equipment. Whether as a result of regulatory obligations relating to these instructions or in the event of a diving accident, their contents may now be used as a basis for analyzing the liability of hirers, lenders or users. Consequently, the increasing judicialization of our societies requires spec...

On the reliability of dive computer generated run-times, Part XI: proposed new features for dive computers. Here, in Part XI, we offer our advice on improving the functionality of diver carried computers. Besides basic dive parameters, these devices usually display "NDL" and the NOAA "ox tox dose" information. For both of these data types there are...

Leseprobe vom Manual: Dekompression Version 2023 / 2024 Vorworte, Inhalts-, Abbildungs, Tabellen- & Formelverzeichnisse, Index

The USS Monitor was an irconclad warship from the american civil war which sunk on 12/31/1862 @ Cape Hatteras, some 14 miles off the coast of North Carolina to ca. 235 feet. By a joint project of USN, NOAA, Global Industries and many others it was partly recovered in an epic effort in 2001 & 2002. One of the main technologies used was saturation di...

Here, in Part V, we give only a short comment about pressure units and the various conversion factors used in diving medicine books, as the majority of these books are using imperial units like pounds per square inch (psi) or feet of seawater (fsw), but for serious scientific publications or technical documentation the SI system, the „International...

Here, in Part X, we offer our conciliatory proposal of a performance benchmark for diver-carried computers, as these devices are usually sold as “black boxes”, i.e.: the end-user, that is: the diver, is kept completely in the dark concerning the safety/security performance of his/her equipment. This yields also for desktop decompression software....

Für die ÖGTH Jahrestagung am 18.12.2022 in Wien, umreissen wir kurz die folgenden Themen: - Idee & Funktion von Gradientenfaktoren (GF) - Aktuelle Implementierungen - Auswirkungen auf die Tauchgangs-Planung - ganz kurzer Ausflug in die Geschichte - und bieten Literatur zum weiterlesen / experimentieren an.

Here, in Part IX, we performed an extended altitude test with the highly topical SCUBAPRO / Uwatec mix-gas dive computer Galileo 2 TEK / „G2 TEK“ along the Galileo G2 with new firmware and a SHEARWATER PERDIX with the DCIEM software-option. This extended test entails simulated dives at a ca. altitude of 2.200 m above SL during 10 min., 1 h and 2 h...

During our evaluation of some ZH-L16x Helium coefficients [1], we found certain interesting aspects on how dive computers calculate a box dive profile with Heliox21 mixture as the sole breathing gas and how diving contractors would handle the same profile in a completely different way. One keyparameter for our comparison was the K-Value index for C...

On the arbitrariness of the ZH-L Helium coefficients (16.08.2022): during our tests [1] with the highly topical SCUBAPRO / Uwatec mix-gas dive computer G2 TEK and the SHEARWATER PERDIX, we found divergent results in Heliox run-times. Thus we set to work to scrutinize the sources of the Helium coefficients within the ZH-L framework [attachment], whi...

On the reliability of dive computer generated run-times, Part VIII: G2 TEK Abstract: Here, in Part VIII, we performed some basic comparisons with the highly topical SCUBAPRO / Uwatec mix-gas dive computer Galileo 2 TEK / G2 TEK along the SHEARWATER PERDIX. Both have been set to a standard perfusion model ZH-L 16 without and as well with gradient f...

Here, in Part VII, we performed an altitude test, i.e. the simulation of diving in a mountain lake. During the previous parts I to VI ([1] to [6] and all the references therein), we observed by some of the dive computer manufacturers deviations from documented algorithms/decompression models with simulated dives on sea-level (SL), whereas Part VII...

The United States Navy air diving tables from the U.S.N. Diving Manual Revision 7 [1] are widespread in military & professional use all over the world [2]. In fact, the precursor editions of these air-diving tables have or had been adopted by nearly all major civilian diver-training agencies like PADI, NAUI, SSI and the like. We selected several ai...

Überblick über Hintergründe & Anwendungen des "K-Wert"- Algorithmus. Der K-Wert ist ein "severity index" zur CNS- & P-OT, den Schädigungen durch hyperbaren Sauerstoff von Ran Arieli et al. [1] bis [5] und alle darin genannten Referenzen.

The mapping of the DCIEM Air-diving table to a standard Haldane-/Workman-/Schreiner-algorithm Abstract: As we demonstrated recently ([1] and all the references therein) selected air-diving schedules from the DCIEM framework ([2] & [3]) could be recovered using a simple desktop decompression shareware with only one additional parameter: a conservat...

The DCIEM air diving tables [1] are widespread in professional use [2] and considered conservative due to a low rate of DCS ([3], [4] & [5] and all the references therein). We selected several air diving schedules incl. repetitive dives from the recreational / TEC diving community and tried to recover these schedules from the printed DCIEM tables w...

On the reliability of dive computer generated run-times, Part VI: Error Propagation Abstract: Here, in Part VI, we only point out to the law of error propagation. During the previous 5 parts ([1] to [5] and all the references therein), we observed by some of the dive computer manufacturers deviations from documented algorithms/decompression models...

On the reliability of dive computer generated run-times (22.02.2022) Part IV Here, in Part IV, we checked the DCIEM implementation of one SHEARWATER® dive computer with the original source, the air diving table from the DCIEM Diving Manual [1] along selected table entries. Conclusion: the manufacturers claims on using the DCIEM model could be ver...

On the reliability of dive computer generated run-times 07.02.2022, Part V Here, in Part V, we checked the ZH-L16C implementation of one SHEARWATER® dive computer with the original source, the air diving table ZH-86 from A. A. Bühlmann [2] along selected table entries as well with a freeware/shareware implementation [1], [3] as a 2nd. benchmark. C...

On the reliability of dive computer generated run-times: Part III Here, in Part III, we checked 3 simple run-times with bottom depth 18 m / 60 min, 33 m / 60 min & 51 m / 30 min bottom times on air with the RATIO iX3M DEEP from Dive System® in comparison with the original source, the ZH-86 from A.A. Bühlmann [2] and DIVE Version 3_11 [1] & [3]. C...

Executive editing" is an off hand change of calculated entries in the printed / published versions of diving tables. Usually, nowadays, the tables entries are calculated via an algorithm, written in a high-level computer language, like "FORTRAN" or "C" and thus coded into a piece of software. The deviations from the automated, algorithmically gener...

The ZH-86 air diving tables and A.A. Bühlmanns underlying ZH-L16 algorithms are considered "gold standard" within the recreational diving community, thus they are widely used in decompression planning software and dive computers. In order to achieve a transparent comparability between the various methods of calculating a diving schedule and thus ge...

Risk Assessment in the Norwegian Diving & Treatment Tables: our offer for improvement Abstract: The NDTT 5th. Ed. describes a transparent & straight-forward score-based risk assessment with 3 clear parameters (Ref. [1], p. 65). We used (de-)hydration as a 4th. parameter, based on our experience [2], as an offer for quick & easy improvement.

On the reliability of dive computer generated run-times, 11.01.2022, Part II Abstract: Here, in Part II, we checked a simple run-time (bottom depth 45 m / bottom time 30 min on air) with the 3 different dive computers in comparison with the original source, the ZH-86 from A.A. Bühlmann and two free-ware desktop deco-programs. Results: there is s...

Abstract: a somewhat belated case study for a sub-saturation dive on air to 8.5 m required for a GUINNESS® world-record of 36 h in-door underwater spinning in 2001 Methods: we analyzed the dive profile with the: USN Rev. 7 2018 tables [1], the DCIEM 1983 tables [2] and the shareware DIVE Version 3_11 from 11/2021 [3], [4]. Results: in one of the...

Abstract / Methods / Results: as per Part I. i.e.: DOI: 10.13140/RG.2.2.15199.79528 We compiled lists/descriptions of errors found in the standard diving medicine literature. We scanned our diving medicine archives and looked there for already existing error-reports; typos etc. were ignored. Severe errors are appearing more frequently in monograph...

Abstract: We compiled lists/descriptions of errors found in the standard diving medicine literature. Methods: We scanned our diving medicine archives and looked there for already existing error-reports; typos etc. were ignored. Results: Severe errors are appearing more frequently in monographs. Omnibus Volumes, written by teams of experts, are ob...

Kapitel 14 aus "Dekompression": Fehlerchen im Bühlmann Konvolut, S. 368 - 372

Abstract: in Part I we checked a simple run-time for a dive with: @bottom depth 42 m / bottom time 25 min. with 2 breathing gases (air & Trimix21/50) with the Scubapro/UWATEC G2 computer with various firmware releases from 2017 up to now (08 / 2021). Methods: pls. cf. slides # 3 to 11, and References [1], [2] & [4], [5] Results: there is variati...

The K-value power functions for the central nervous system and pulmonary oxygen toxicity (CNS-OT, P-OT) are described in: [1], [2], [3], [4] & [5], pls. cf. chapter „References“. As Ran et al. would have it ([3], abstract), there is a need for an implementation. Which is what we did ([6], [7], [8], [9]). „Agile“ means here, in the context of IT-...

If there is more than one inertgas in the breathing mixture, the calculation of the decompression-time td has to be done numerically. We analyzed 480 square / box dive-profiles in the TEC/REC range with one freeware, two commercially available software-packages and via numerical methods (depth range: 30 - 80 m, bottom times: 20 - 60 min, helium per...

PoC: proof of concept DIVE: a decompression suite as a free-/shareware for: dive / decompression planning with open system / SCUBA bounce/jump/sprint dives in the TEC & recreational domain saturation diving custom models for: diving at reduced ambient pressure, low water temperature diving with high workload / oxygen consumption C&R diving, Caisso...

Abstract: The published french air diving tables MT92 ([1] & [2]) could be mapped via a simple algebraic transformation directly to a standard decompression algorithm based on blood perfusion with a linear relationship between calculated compartment inert gas overpressures and the ambient pressure. With this mapping the MT92 table entries could b...

On the theoretical evaluation of one yo-yo diving profile on air for fish-farming Abstract: A yo-yo diving profile is one with very rapid and repeated depth changes. Due to the speed of depth changes in excess of 20 m/min and the quickly repeated ascents and descents within 1 to 5 min, a standard decompression model based on perfusion or a dive co...

On the statistical probability of contracting a decompression sickness after a single scuba dive on air within a no-decompression-limit The P(DCS) is the statistical probability of contracting a decompression sickness, the NDL are the so-called „No Decompression Limits“, the time limits for dives where a direct ascent to the surface is still possi...

Adaption of a COMEX procedure for recreational bounce dives on air: a COMEX decompression procedure, once developped for deep experimental and saturation dives with Heliox is adapted for the use in the deep diving range for recreational & technical bounce dives on regular breathing air. As well a comparison is done between different staging proto...

A „deep stop“ table for recreational dives on air: Debunked! A "deep stop" table is challenged with 2 box-profiles: the authors claims of reduced decompression stress and additional safety due to deep stops are analyzed. An in-depth analysis of the calculated inertgas partial pressures in theoretical tissue compartments reveals that the additiona...

Ist die DGUV Vorschrift 40 angepaßt für Taucher-“Arbeit“? Die DGUV 40 wird anhand eines exemplarischen Box-Profiles geprüft, inwieweit die körperliche Belastung unter Wasser berücksichtigt ist. Aus den Abweichungen zu bewährten / implementierten Standardmethoden läßt sich zeigen, daß dies nicht der Fall ist. Für anstrengendere Taucher-Arbeiten wir...

Comparison of the air diving tables DCIEM and ZH-86 with DGUV Vorschrift 40 and DIVE Version 3_09 (english version of: DOI: 10.13140/RG.2.2.28277.40169) DGUV follows precisely the ZH-86 within the „protective envelope“(< 30 m, < 30 min). Marginal deviations of +/- 1 min per ZH-86 resp. DIVE Version 3_09 stem, among others, from different ascent ra...

Is the „DGUV Vorschrift 40“ adequate for underwater-“work“? The DGUV 40 is challenged with a certain paradigm of one box profile to check whether this regulation is adequate for underwater work, i.e.: physical workload. According to other approved methods this seems to be not the case. Thus the recommendation is not to use the DGUV 40 for strenous...

Vergleich der Pressluft-Tabellen ZH-86 und DGUV Vorschrift 40 mit DCIEM und DIVE Version 3_09 anhand exemplarischer Box-Profile Zusammenfassung: DGUV folgt präzise ZH-86 innerhalb der „schützenden Einhüllenden“(< 30 m, < 30 min). Marginale Abweichungen +/- 1 min zu ZH-86 bzw. DIVE Version 3_09 rühren u.a. von den unterschiedlichen Aufstiegsgeschw...

ZH-L12: Validation of an old (1982) experimental Heliox jump dive (30 m, 120 min): Question: could we verify the old ZH-L12 decompression profile with a topical desktop deco software?

This little essay gives a short primer on „catastophe theory“ and tries to give connections to decompression sickness (DCS). The surface of a cuspoid, non-linear potential function and the derivatives are linked to P(DCS), the statistical probability of contracting DCS and to Hemplemans decompression stress assessment.

"Historical Divetables" gives an overview of ca. 110 years of dive tables development, tests and the results: the printed tables. There are copies & extracts of 24 tables and 2 procedures. "Historische Tauchtabellen" gibt einen Überblick über ca. 110 Jahre Entwicklung, Test und die Ergebnisse, die gedruckten Tabellen. Es gibt 24 Tabellen, komplett...

The relative and absolute performance of 4 dive computers on a controlled bounce dive to 50 m on air: 4 standard dive computers (Scubapro G2, Aladin TEC 2G, Ratio iX3m and Cochran EMC-20 H) are compared relative to each other and with well-tried air diving tables like: United States Navy USN old 1990, USN new 2018, DCIEM 1992, DRÄGER 1984 and Dec...

the following is an essay on some aspects of DCS and the relation to just one of the 7 so-called elementary catastrophes, the cusp. Thus it is not a strict scientific paper, neither in form nor in contents but delineates a couple of preliminary thoughts on the topic, intended to raise awareness or as a basis for further discussions. As well this s...

Fats- & superfast compartments

Basics of dual phase theory and its application in diving. What is “Dual Phase”? (only short) Overview on Bubble Models basic bubble physics, kavitation and tribonucleation, bubble dynamics and evolution: Why does a bubble exist and why does it grow or shrink? The critical diameter concept The role of bubble seeds (gas nuclei) How does a bubble ex...

Über schnelle und superschnelle Kompartimente, in: CAISSON, Jg. 33, Nr. 2, April 2018, S. 6 - 19

Essay on Fast and Superfast Compartments

Dive computers for mixed gas diving and PC software for decompression calculations are often considered as 'black boxes' to the diver: they perform part of their function-the calculation of a decompression schedule-but leave the user in a somewhat nebulous state about the relative safety of this schedule. This is because, in reality, the technology...

If there is more than one inertgas in the breathing mixture, the calculation of the decompression-time t d has to be done numerically. We analyzed 480 square dive-profiles in the TEC/REC range with one freeware, two commercially available software-packages and via numerical methods (depth range: 30-80 m, bottom times: 20-60 min, helium percentage:...

Chapter 5 of 2nd edition: the 3rd edition (ISBN 978-3-87247-771-2) will be available soon! A. Salm: Weltweit bewegen sich Menschen unter Wasser: als Forscher, Soldaten, Arbeiter in Fischfarmen oder Tunnelbauten, Retter, Polizisten und Freizeitsportler. Den größten Anteil machen die Freizeitsportler aus. In diesem Segment tummeln sich auch die so g...

A Salm CAISSON 26. Jg./2011/Nr. 3 4 www.gtuem.org Grundlagen Mit 'Algorithmus' ist die Rechenvorschrift für eine Inertgas-Buchhaltung bei einer Überdruck-Exposition subsummiert, mit 'Implementierung' die praktische Umsetzung dieses Algorithmus in eine Desktop-Deco-Software für den PC oder auch in eine Hardware, den Tauchcomputer. Mit 'Gradientenf...