People with diabetes, especially children and adolescents, have been usually discouraged to dive due to the specific risk of hypoglycemia. In order to prevent hypoglycemia and dive safely, Continuous Glucose Monitoring System (CGMS) seem to be a valid option to manage children with diabetes approaching to diving. The aim of the study was to evaluate performance of a “suited” CGMS in Type 1 Diabetic adolescents during a three days diving session. Four Type 1 diabetic patients, 12 to 16 years old, intensively insulin treated and previously patented for scuba diving were enrolled in a three days diving performance test. The CGMS receiver was kept in a waterproof case, specifically made for scuba diving activities. No significant differences between CGM and SMBG glucose values have been reported, both before and after diving; all dive sessions didn’t cause a glucose fall and no significant differences in glucose levels measured before and after diving have been reported, both by CGM (226 ± 67 mg/dl vs 205 ± 75 mg/dl) and SMBG (214 ± 55 mg/dl vs 220 ± 77 mg/dl). Referring to hyperbaric exposure, all patients resulted with a Gradient Factor between 0.2 and 0.4, identifying a very low risk for Decompression Sickness. Our experience, the first with Real Time-CGM in children with Type 1 Diabetes (T1D), demonstrated that a waterproof cased CGMS is essential in order to allow children with diabetes diving safely, avoiding hypoglycemia when underwater. The waterproof cased CGM was accurate and safe.

INTRODUCTION:Neurological symptoms after breathhold (BH) diving are often referred to as "Taravana" and considered a form of decompression sickness. However, the presence of "high" gas embolism after BH diving has never been clearly shown. This study showed high bubble formation after BH diving.MATERIALS and METHODS:We performed transthoracic echocardiography on a 53-year-old male spearfishing diver (180 cm; 80 kg; BMI 24.7) 15 minutes before diving and at 15-minute intervals for 90 minutes after diving in a 42-meter-deep pool. Number of dives, bottom time and surface intervals were freely determined by the diver. Dive profiles were digitally recorded for depth, time and surface interval, using a freediving computer. Relative surface interval (surface interval/diving time) and gradient factor were calculated.REULTS:High bubble grades were found in all the recorded echocardiograms. From the first to third recording (45 minutes), Grade 4 Eftedal-Brubakk (EB) bubbles were observed. The 60-, 75- and 90-minute recordings showed a reduction to Grades 3, 2 and 1 EB. Mean calculated GF for every BH dive was 0.22; maximum GF after the last dive was 0.33.CONCLUSIONS:High bubble grades can occur in BH diving, as confirmed by echocardiographic investigation. Ordinary methods to predict inert gas supersaturation may not able to predict Taravana cases.

The main objective of the CADDY project is to replace a human buddy diver with an autonomous underwater vehicle and add a new autonomous surface vehicle to improve monitoring, assistance, and safety of the diver's mission. However, the use of robots underwater may also bring additional safety requirements. Within the scope of this research, the existing vehicles that will be adapted for the purposes of the CADDY project were evaluated regarding safety issues. This will mainly focus on the vehicles' maneuvering capabilities as an indicator of whether the vehicles are safe to be used for interaction with divers. The hazards of ancillary equipment such as scaling lasers and acoustic modems were addressed as well. The design requirements, as well as the formal hazard identification and risk assessments guideline (HIRA) is developed in the beginning of the project to provide operational safety for each manned diving operation. All the CADDY vehicles are modified in order to comply with the design rules for safety. In fact, by the end of February 2015, 44 dives were conducted with a cumulative dive time of 1545 minutes without any accident. The HIRA and the diving methodology are proven to be effective means of safety.

OBJECTIVEScuba and breath-hold divers are compared to investigate whether endothelial response changes are similar despite different exposure(s) to hyperoxia.DESIGN14 divers (nine scuba and five breath-holding) performed either one scuba dive (25m/25 minutes) or successive breath-hold dives at a depth of 20 meters, adding up to 25 minutes of immersion time in a diving pool. Flow-mediated dilation (FMD) was measured using echography. Peripheral post-occlusion reactive hyperemia (PORH) was assessed by digital plethysmography and plasmatic nitric oxide (NO) concentration using a nitrate/nitrite colorimetric assay kit.RESULTSThe FMD decreased in both groups. PORH was reduced in scuba divers but increased in breath-hold divers. No difference in circulating NO was observed for the scuba group. Opposingly, an increase in circulating NO was observed for the breath-hold group.CONCLUSIONSome cardiovascular effects can be explained by interaction between NO and superoxide anion during both types of diving ending to less NO availability and reducing FMD. The increased circulating NO in the breath-hold group can be caused by physical exercise. The opposite effects found between FMD and PORH in the breath-hold group can be assimilated to a greater responsiveness to circulating NO in small arteries than in large arteries.

In our previous research, a deep 5-min stop at 15 msw (50 fsw), in addition to the typical 3-5 min shallow stop, significantly reduced precordial Doppler detectable bubbles (PDDB) and "fast" tissue compartment gas tensions during decompression from a 25 msw (82 fsw) dive; the optimal ascent rate was 10 msw (30 fsw/min). Since publication of these results, several recreational diving agencies have recommended empirical stop times shorter than the 5 min stops that we used, stops of as little as 1 min (deep) and 2 min (shallow). In our present study, we clarified the optimal time for stops by measuring PDDB with several combinations of deep and shallow stop times following single and repetitive open-water dives to 25 msw (82 fsw) for 25 mins and 20 minutes respectively; ascent rate was 10 msw/min (33 fsw). Among 15 profiles, stop time ranged from 1 to 10 min for both the deep stops (15 msw/50 fsw) and the shallow stops (6 msw/20 fsw). Dives with 2 1/2 min deep stops yielded the lowest PDDB scores--shorter or longer deep stops were less effective in reducing PDDB. The results confirm that a deep stop of 1 min is too short--it produced the highest PDDB scores of all the dives. We also evaluated shallow stop times of 5, 4, 3, 2 and 1 min while keeping a fixed time of 2.5 min for the deep stop; increased times up to 10 min at the shallow stop did not further reduce PDDB. While our findings cannot be extrapolated beyond these dive profiles without further study, we recommend a deep stop of at least 2 1/2 mins at 15 msw (50 fsw) in addition to the customary 6 msw (20 fsw) for 3-5 mins for 25 meter dives of 20 to 25 minutes to reduce PDDB.

In spite of many modifications to decompression algorithms, the incidence of decompression sickness (DCS) in scuba divers has changed very little. The success of stage, compared to linear ascents, is well described yet theoretical changes in decompression ratios have diminished the importance of fast tissue gas tensions as critical for bubble generation. The most serious signs and symptoms of DCS involve the spinal cord, with a tissue half time of only 12.5 minutes. It is proposed that present decompression schedules do not permit sufficient gas elimination from such fast tissues, resulting in bubble formation. Further, it is hypothesized that introduction of a deep stop will significantly reduce fast tissue bubble formation and neurological DCS risk. A total of 181 dives were made to 82 fsw (25 m) by 22 volunteers. Two dives of 25 min and 20 min were made, with a 3 hr 30 min surface interval and according to 8 different ascent protocols. Ascent rates of 10, 33 or 60 fsw/min (3, 10, 18 m/min) were combined with no stops or a shallow stop at 20 fsw (6 m) or a deep stop at 50 fsw (15 m) and a shallow at 20 fsw (6 m). The highest bubbles scores (8.78/9.97), using the Spencer Scale (SS) and Extended Spencer Scale (ESS) respectively, were with the slowest ascent rate. This also showed the highest 5 min and 10 min tissue loads of 48% and 75%. The lowest bubble scores (1.79/2.50) were with an ascent rate of 33 fsw (10 m/min) and stops for 5 min at 50 fsw (15 m) and 20 fsw (6 m). This also showed the lowest 5 and 10 min tissue loads at 25% and 52% respectively. Thus, introduction of a deep stop significantly reduced Doppler detected bubbles together with tissue gas tensions in the 5 and 10 min tissues, which has implications for reducing the incidence of neurological DCS in divers.

The requirements of medical research on recreational diving differs from those of military or commercial diving. This is principally due to the fact that recreational diving is not easily reproducible in a laboratory because of the wide variety of profiles and practices utilized by recreational divers world-wide. A recreational dive may vary from the relatively shallow, repetitive dive carried out in the Caribbean to the single deep daily dive usually practised in the Mediterranean.