Nurit Vered

• Doctor of Medicine
• PostDoc Position at Technion – Israel Institute of Technology

This somewhat cryptic title refers not to a topical, the 4.0 version, of an abstruse blondie but to the epic work of Kenneth Donald: "Oxygen and the diver" [1]. We had another fresh look, inspired by [2] and focused on the CNS ox-tox experiments, basically chapter 2 of his book. The chamber dives with oxygen producing symptoms of oxygen-intoxicatio...

The diving medical detectives: when diving medicine books are completely wrong. Here in Part VI of this series we give only a short comment on the 5th. edition of Bennett & Elliot‘s Physiology and Medicine of Diving, concerning two errors on p. 440.

The DCIEM Heliox diving tables are wide-spread in professional use and considered conservative due to a low rate of DCS. Their counterpart tables from the United States Navy (USN), the so-called surface-supplied Heliox (He-O2) tables have had a long history: the first version from Momsen et al. appeared in 1939 with heavy field-tests along the ep...

The DCIEM Heliox diving tables [2] are widespread in professional use [1] and considered conservative due to a low rate of DCS ([3], [4] & [5] and all the references therein). We selected two Heliox diving schedules as primary, 1st. dives on the day, and tried to emulate these schedules from the printed DCIEM tables with a simple, publicly availabl...

We present some reflections on repetitive diving, along the following paradigm from recreational scuba dives on air: 1st. dive on the day: 30 m bottom depth, 30 min bottom time surface interval (SI): 90 min 2nd. dive: 30 m bottom depth, 30 min bottom time We compare seasoned dive tables with dive computer simulations, have a look back at repetiti...

We present a numerical simulation of a pulmonary Right-to-Left Shunt (R-/L shunt) model, developed by Bühlmann. This model was implemented into a publicly available desktop decompression shareware and used to demonstrate, how a Gradient Factor System could be used to map the original ZH-L16C system to repetitive dive data and reproduce a certain s...

In a trailblazing study from the Navy Experimental Diving Unit traditional shallow and deep stops schedules have been analyzed. As the shallow schedule did reveal significant less DCS cases in comparison to the deep stop schedule, we set about to emulate the shallow schedule with a decompression shareware using a standard perfusion model with 16 pa...

Eine Einführung in die Dekompressionsrechnung mit einfachen Beispielen; Bonus Material für GTÜM-Diplom IIa Taucherarzt: anhand eines simplen Box-Profils (30 m, 50 min, Luft) werden mit gerundeten Zahlen Inertgaspartialdrücke, Inertgassättigungen sowie Dekompressionszeiten geschätzt. Alle hierfür erforderlichen Formeln werden exemplarisch ausgeführ...

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...

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...

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.

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...

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.

Traditional Air-DivingTables and DIVE Version 3_11: Synopsis & update per 06/2022: as an extended quality-assurance assessment (or PoC) for the adaptivity, accuracy and usefulness of the DIVE Versions 3 framework there are now publicly available documents on RESEARCHGATE with in-depth comparisons along established and proven air-diving tables from...

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...

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: 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 obvi...

Synopsis & fact sheet for the Desktop Decompression Suite DIVE, Version 3_11; new features being the K-Index for CNS- & P-OT, as well the DCIEM deco stress index "I".

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...

Synopsis & Fact Sheet: an update per 07/2021 wit new materials / publications for a Proof of Concept (PoC) for DIVE Version 3_10; including links to: --> Collateral Aspects of DCS --> an agile implementation of the K-value, a severity index for CNS-OT & P-OT (oxygen toxicity for the CNS and the pulmonary system)

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-...

Background Information on the "update 03 / 2021" to the 2011 paper from smc-de.com: Decompression-Calculations for Trimix Dives with PC-Software; Gradient Factors: do they repair defective algorithms or do they repair defective implementations?

Synopsis: some collateral aspects of DCS A collection of papers / essays / presentations and their URLs at researchgate.net, related to DCS (decompression sickness), PBPK (physiologically based pharmaco-kinetic models), diving and their somewhat remote, unusal or at least, unorthodox aspects.