Alen Soldo - Security issues in scientific diving

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SECURITY ISSUES IN SCIENTIFICSECURITY ISSUES IN SCIENTIFICDIVINGDIVING

ALEN SOLDOALEN SOLDOCentre for Marine Studies, University of Split, CroatiaCentre for Marine Studies, University of Split, Croatia

Head of Diving Activities, Instructor of Scientific Diving, PSS & CMAS Diving Instructor Head of Diving Activities, Instructor of Scientific Diving, PSS & CMAS Diving Instructor

IPSIT 2011 ± WORKSHOP INTELLIGENT UNDERWATER SYSTEM AND TECHNOLOGIES, 1. 4. 2011., SPLIT - CROATIA



SCIENTIFIC DIVING:

- diving performed solely as a necessary part of ascientific, research, or educational activity.

DIVING IN BIOLOGY AND BIOTECHNOLOGY:

1. BIOLOGY & ECOLOGY MARINE SPECIES- Fish behaviour

- Visual census

- Marine mapping/charting

2. FISHING GEAR

- Impact of fishing gear

� Marine habitat

� Marine species

- Fishing gear characteristics



Fish behaviour



Visual census:

- species richness

- species abundance

- species biomass

10 m



Marine mapping / charting



Impact of fishing gear:- marine habitat



Impact of fishing gear:- marine species



Underwater research of fishing gear characteristics:

- Stationary fishing gear

- Movable fishing gear



Criteria for scientific diver certification.

Safety procedures for the diving operation.

Responsibilities of the dive team members.

Emergency procedures.

Equipment use and maintenance procedures.

Each dive unique.

Security issues based on:

³SAFETY FIRST PRINCIPLE´



EXAMPLE 2: TUNA CAGE MONITORING



DIVING PLAN

DIVING AT LOCATIONS:

1.Under and in vicinity of cage (depth 60-65 m)

2.Reference point (depth 60-70 m): no cage influence

3.Coastal transect in cage vicinity (40-45 m)

EQUIPMENT BASED ON DIVING TARGET / ACTIVITY:

- HD Video camera + underwater case + HID artificial lights

- Marine sediment sampling corer

GAS MIXTURE ??:

-Air

-Nitrox

-Trimix (Oxygen + Nitrogen + Helium)



SEDIMENT SAMPLING

UNDERWATERVIDEORECORDINGANDM

ONITORING



PROBLEMS:

NITROGEN ± HIGH PARTIAL PRESSURE CAUSING NITROGEN NARCOSIS

OXYGEN ± HIGH PARTIAL PRESSURE >1,4 BAR; >1,6 BAR = OXYGEN TOXICITY

GAS ADVANTAGE DISADVANTAGE

Air Simplest, most available,cheapest

High ppN2 + ppO2

Nitrox Lower ppN2 Higher ppO2 = not for deepdives, lower availability,expensive, technically demanding

Trimix Reduced proportions of nitrogen and oxygen, lownarcotic effect of helium,helium leaves tissue morerapidly than nitrogen

Most expensive, low availability,most complicated dives,technically most demanding,helium dissolves into tissuesmore rapidly



Cardiovascular

parameters here

Multiday trimix diving

HEART FUNCTION DECREASED!

Pro-BNP hormone: released after damaging

Diving and cardiac function



Venous gas bubbles (emboli) Regularly produced in venous circulation during ascent

Hypothesized to cause D S

However, high VG has a weak positive predictive power(Sawatzky KD, 1991)

A lternative theory: endothelial damage at bottom as primary event, bubbles exacerbate condition (collateral finding)(Madden & Laden 2009)



Grading of vascular gas bubbles Doppler ultrasound (Spencer and Johanson scale, Kisman-Masurel

scale)

Two-dimensional echocardiography ( ftedal & Brubakk 1997)



Echocardiographic imaging

Logicbook

GE Vivid 3 GE Vivid q (latest technology)

Ultrasound Doppler

Application of new techniques in

assessment of VGE dynamics and

distribution



Gas bubbles arterializations Crossover of VG to systemic circulation Usually linked to patent foramen ovale (PFO) Rarely observed and speculated to increase the risk of

decompression injury Long term effects unknown C

erebral embolization, fatigue after dive?TEE excluded PFO



Seven experienced male divers

Three dives in consecutive days

Depth: 65-70 msw, trimix andnitrox 50

Protocols constructed with V-planner (Varying Permeability 1Model VPM-B)

Gas bubbles monitoredechocardiographically for 90 minpostdive

P A P assessed as A ccT/RV T ratio

Rogoznica study (2009)



Rogoznica study (trimix) High i ci e ce f high-gr e VGE etecte Freque t VGE cr ss ver t syste ic circul ti (9 f 21 ives, i 5 ut

f 7 ivers)

ll c ses f rteri liz ti p r llele with VGE gr e 4 i right he rt

N verse cli ic l utc es bserve /rep rte

I cre se P P

Dive

No

Bubble Grade

45¶ 60¶ 90¶

Dive 1 4 (3 ± 4) 3 (3 ± 4) 3 (3 ± 4)

Dive 2 3 (1 ± 4) 3 (1 ± 4) 3 (0 ± 4)

Dive 3 3 (0 ± 4) 3 (0 ± 4) 2 (0 ± 3)

Subject NoDive 1 Dive 2 Dive 3

45¶ 60¶ 90¶ 45¶ 60¶ 90¶ 45¶ 60¶ 90¶

Subject 1

Subject 2 A A A A

Subject 3

Subject 4 A A A A

Subject 5 A A A

Subject 6 A

Subject 7 A



Conclusions

Existing of high VGE production and their frequentarterialization after dives based on commonly used

models and dive tables High VGE production during air, nitrox and trimixdives No acute decompression-related pathology observed Long term adverse effects of recurrent microemboli insystemic circulation cannot be excluded (vital organs) Individual susceptibility to VGE production andarterialization



DEPTH

DEEP DECO STOPS (air)



LATEST DIVING ACCIDENTS IN THE

ADRI ATIC



REBREATHER INCIDENT 24 July 2010 - Trieste

As the diver exhalesinto the rebreather, thecounterlung(s)

expand. As the diver inhales from the

rebreather, the

counterlung(s) collapse.

The exhaled gas is

supposed to pass

through a carbondioxide absorbent, and

fresh gas containing

oxygen is supposed to

be added.



Probable cause:

Rebreather malfunction = HYPOXIA

Course reserved for experienced divers

Two slovenian scientist died: - one found dead,- second 40 min cardiac arrest (brain anoxia) Shallow water 4 m depth



THANKS FOR ATTENTION!

Alen Soldo - Security issues in scientific diving

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