Change search
Refine search result
12 1 - 50 of 79
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the Create feeds function.
  • 1. Bense, L
    et al.
    Eklund, G
    Jorulf, H
    Farkas, A
    Balashazy, I
    Hedenstierna, G
    Krebsz, A
    Balazs, G
    Eden Strindberg, J
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Douglas, J
    Perforation of the right main bronchus, detected by HRCT 3D technique2011Conference paper (Refereed)
  • 2. Bense, L
    et al.
    Jorulf, H
    Farkas, A
    Eden-Strindberg, J
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Jokay, A
    Krebsz, A
    Pulmonary gas conducting interstitial pathway2015In: Acta Radiologica Open, ISSN 2058-4601, Vol. 4, no 10, p. 1-5Article in journal (Refereed)
    Abstract [en]

    In spite of the growing efforts oriented towards revealing different aspects of emphysema, the persistence of the emphysematous or emphysema-like changes (ELCs) is not explored yet in the open literature. In this study we demonstrate the persistence of an ELC for 22 years in a spontaneous pneumothorax (SP) patient which indicates a hitherto unknown gas supply to the ELC. For this purpose we used high resolution computed tomography (HRCT) images processed into three-dimensional (3D) geometry. By the same token, not only a long persistence but also the volume increase of this ELC between 2002 and 2010 was demonstrated. The 3D geometry visualized an aerated interstitial structure between the sites of supposed gas leakage at the wall of the third generation airways and the ELC. This potential gas conducting interstitial pathway is not a continuation and has neither the form nor the structure of a bronchus. The finding suggests that in this patient the intrabronchial gas passes through the bronchial wall and via a gas conducting interstitial pathway reaches the ELC. Despite the availability of the presently employed techniques for at least 15 years, such case and phenomenon have not been described previously. The retrieval of the patient suggests that the findings could be relevant for a considerable proportion of the population.

  • 3. Berglund, B
    et al.
    Gennser, Mikael
    Swedish Defence Research Agency.
    Ornhagen, H
    Ostberg, C
    Wide, L
    Erythropoietin concentrations during 10 days of normobaric hypoxia under controlled environmental circumstances.2002In: Acta Physiologica Scandinavica, ISSN 0001-6772, E-ISSN 1365-201X, Vol. 174, no 3, p. 225-229Article in journal (Refereed)
    Abstract [en]

    Serum erythropoietin levels (s-[epo]), haemoglobin concentration ([Hb]), haematocrit (hct), and ferritin concentration ([fer]) were measured in seven healthy male volunteers (20-23 years) exposed continuously to hypoxia (PO(2) 14 kPa) for 10 days. Serum erythropoietin concentration increased significantly from 9.5 +/- 3.51 to 33.6 +/- 11.64 U L(-1) (P < 0.05) after 2 days of hypoxia. Thereafter, s-[epo] decreased. However, after 10 days s-[epo] was 18.7 +/- 5.83 U L(-1) which was still increased above the pre-hypoxia level (P < 0.05). Serum haemoglobin concentration and hct increased over the 10 days of hypoxia, [Hb] from 152 +/- 8.9 to 168 +/- 9.2 gL(-1) (P < 0.001), and hct from 43 +/- 2.4 to 49 +/- 2.6% (P < 0.001). Ferritin concentration decreased significantly during the hypoxic exposure from 82 +/- 46.9 to 44 +/- 31.7 mmol L(-1) after 10 days (P < 0.01). In conclusion, the initial increase of s-[epo] under controlled normobaric hypoxia was marked, 353%, and levelled off after 5-10 days at 62-97% above normoxia level. There was also a significant increase in [Hb] and hct and a decrease in [fer] after 10 days of exposure to normobaric hypoxia.

  • 4. Blogg, L
    et al.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Arterial bubbles following trimix dives2014Conference paper (Other academic)
  • 5. Blogg, L
    et al.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Direct comparison of audio Doppler ultrasound scores and 2D ultrasound images of venous gas emboli.2010Conference paper (Refereed)
  • 6. Blogg, L
    et al.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Near maximal venous bubble scores and arterial bubbles with no signs or symptoms of DCS - a case study.2011Conference paper (Refereed)
  • 7. Blogg, L
    et al.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Predisponerar helium i dykgasen för arteriella bubblor?2014Conference paper (Other academic)
    Abstract [sv]

    Bakgrund: Bubblor i den arteriella cirkulationen observerades första gången vid 10 av 12 exkursioner från heliox- (O2/He) och trimix- (O2/He/N2) mättnad (1).  På senare tid har Ljukovic et al (2) redovisat resultat av trimixdykningar där 5 av 7 dykare uppvisade arteriella bubblor. Visserligen har arteriella bubblor observerats även i samband med nitrox- och luftdykningar men inte i så hög frekvens. Gör heliumgasen att bubblor lättare tar sig igenom lungfiltret?

    Metoder: Dykare undersöktes med kardiellt ekokardiografi efter 251 trimixdykningar och 37 nitroxdykningar med varierande dykprofiler. Dykdjupen varierade mellan 20 – 100 m för trimixdykningarna och 33 – 60 m för nitroxdykningarna. Totalt 43 dykare deltog i trimix- och 19 dykare i nitroxdykningarna. Dykarna undersöktes varje kvart i 2 timmar efter dykningarna. Förekomst av venösa och arteriella bubblor registrerades och skattades enligt Brubakk-Eftedal-skalan (EB).

    Resultat: Totalt observerades arteriella bubblor hos 3/43 dykare efter trimixdykning och hos 3/19 dykare efter nitroxdykning. En av dykarna med arteriella bubblor i nitroxgruppen behandlades för ledbends. Två av dykarna hade arteriella bubblor både efter trimix- och nitroxdykningar. I samtliga fall med artärbubblor observerades också venösa bubblor (EB 2 – 4c).

    Slutsats: Jämfört med tidigare rapporterad incidens av artärbubblor i samband med trimixdykningar är de redovisade resultaten låga. Resultaten för nitroxdykningarna är också låga givet att ca 25% av normalpopulationen har öppetstående foramen ovale. Någon ökad incidens artärbubblor observerades inte med den heliuminnehållande gasen, utan det mest troliga är att förekomsten av artärbubblor beror på mängden venösa bubblor och individuell predisponering att ”läcka” bubblor från den venösa till den arteriella cirkulationen.

  • 8. Blogg, L
    et al.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Jurd, KM
    Møllerløkken, A
    Observed incidence of decompression sickness and venous gas bubbles following 18 M dives on RN table 11/Norwegian air diving table2015Conference paper (Refereed)
  • 9. Blogg, S. Lesley
    et al.
    Gennser, Mikael
    Swedish Defence Research Agency.
    Cerebral blood flow velocity and psychomotor performance during acute hypoxia2006In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 77, no 2, p. 107-113Article in journal (Refereed)
    Abstract [en]

    INTRODUCTION: The physiological effects of hypoxic environments can help determine safe limits for workers where cognitive and motor performance is important. We investigated the effects of a PIO2 of 15 kPa and 10 kPa on medial cerebral artery blood flow velocity (CBFV) and psychomotor performance.

    METHODS: Over 3 sessions, each involving 3 separate test batteries, 13 subjects breathed either 21 kPa PIO2 (control), 15 kPa PIO2, or 10 kPa PIO2. The tests measured reaction time, spatial orientation, voluntary repetitive movement, and fine manipulation. CBFV, PETCO2, PETO2, Sa02, and BP were recorded throughout.

    RESULTS: ANOVA analysis showed that 15 kPa PIO2 did not significantly change psychomotor test performance. The mean number of incorrect responses in the reaction time test significantly increased to 5.6 (SD - 4.0) while breathing 10 kPa PIO2, as did the mean number of errors (7.7 +/- 5.0) in the fine manipulation test. Only 10 kPa PIO2 affected CBFV, causing a significant increase in flow from 50 +/- 6.5 cm x s(-1) to 55 +/- 10.3 cm x s(-1). CBFV significantly increased during three psychomotor tests while breathing air; however, it did not increase further during psychomotor testing in hypoxia.

    DISCUSSION: A PIo2 of 15 kPa did not affect subject performance, and should not cause operational risk. At 10 kPa PIO2, accuracy and vigilance were slightly affected; however, the reduction in oxygenation was not great enough to cause major decrements. CBFV was not a good indicator of mental stress during hypoxia.

  • 10. Blogg, S. Lesley
    et al.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    The need for optimisation of post-dive ultrasound monitoring to properly evaluate the evolution of venous gas emboli2011In: Diving and hyperbaric medicine : the journal of the South Pacific Underwater Medicine Society, ISSN 1833-3516, Vol. 41, no 3, p. 139-146Article in journal (Refereed)
    Abstract [en]

    Audio Doppler ultrasound and echocardiographic techniques are useful tools for investigating the formation of inert gas bubbles after hyperbaric exposure and can help to assess the risk of occurrence of decompression sickness. However, techniques, measurement period and regularity of measurements must be standardised for results to be comparable across research groups and to be of any benefit. There now appears to be a trend for fewer measurements to be made than recommended, which means that the onset, peak and cessation of bubbling may be overlooked and misreported. This review summarises comprehensive Doppler data collected over 15 years across many dive profiles and then assesses the effectiveness of measurements made between 30 and 60 minutes (min) post-dive (commonly measured time points made in recent studies) in characterising the evolution and peak of venous gas emboli (VGE). VGE evolution in this dive series varied enormously both intra- and inter-individually and across dive profiles. Median, rather than mean values are best reported when describing data which have a non-linear relation to the underlying number of bubbles, as are median peak grades, rather than maximum, which may reflect only one individual's data. With regard to monitoring, it is apparent that the evolution of VGE cannot be described across multiple dive profiles using measurements made at only 30 to 60 min, or even 90 min post-dive. Earlier and more prolonged measurement is recommended, while the frequency of measurements should also be increased; in doing so, the accuracy and value of studies dependent on bubble evolution will be improved.

  • 11. Blogg, S. Lesley
    et al.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Møllerløkken, Andreas
    Brubakk, Alf O.
    Ultrasound detection of vascular decompression bubbles: the influence of new technology and considerations on bubble load2014In: Diving and Hyperbaric Medicine, ISSN 1833-3516, Vol. 44, no 1, p. 35-44Article, review/survey (Refereed)
    Abstract [en]

    Introduction: Diving often causes the formation of 'silent' bubbles upon decompression. If the bubble load is high, then the risk of decompression sickness (DCS) and the number of bubbles that could cross to the arterial circulation via a pulmonary shunt or patent foramen ovale increase. Bubbles can be monitored aurally, with Doppler ultrasound, or visually, with two-dimensional (2D) ultrasound imaging. Doppler grades and imaging grades can be compared with good agreement. Early 2D imaging units did not provide such comprehensive observations as Doppler, but advances in technology have allowed development of improved, portable, relatively inexpensive units. Most now employ harmonic technology; it was suggested that this could allow previously undetectable bubbles to be observed. Methods: This paper provides a review of current methods of bubble measurement and how new technology may be changing our perceptions of the potential relationship of these measurements to decompression illness. Secondly, 69 paired ultrasound images were made using conventional 2D ultrasound imaging and harmonic imaging. Images were graded on the Eftedal-Brubakk (EB) scale and the percentage agreement of the images calculated. The distribution of mismatched grades was analysed. Results: Fifty-four of the 69 paired images had matching grades. There was no significant difference in the distribution of high or low EB grades for the mismatched pairs. Conclusions: Given the good level of agreement between pairs observed, it seems unlikely that harmonic technology is responsible for any perceived increase in observed bubble loads, but it is probable that our increasing use of 2D ultrasound to assess dive profiles is changing our perception of 'normal' venous and arterial bubble loads. Methods to accurately investigate the load and size of bubbles developed will be helpful in the future in determining DCS risk.

  • 12. Blogg, S. Lesley
    et al.
    Mollerlokken, Andreas
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Observed decompression sickness and venous bubbles following 18-msw dive profiles using RN Table 112017In: Undersea & Hyperbaric Medicine, ISSN 1066-2936, Vol. 44, no 3, p. 211-219Article in journal (Refereed)
    Abstract [en]

    The venous bubble load in the body after diving may be used to infer risk of decompression sickness (DCS). Retrospective analysis of post-dive bubbling and DCS was made on seven studies. Each of these investigated interventions, using an 18 meters of sea water (msw) air dive profile from Royal Navy Table 11 (Mod Air Table), equivalent to the Norwegian Air tables. A recent neurological DCS case suggested this table was not safe as thought. Two-hundred and twenty (220) man-dives were completed on this profile. Bubble measurements were made following 219 man-dives, using Doppler or 2D ultrasound measurements made on the Kisman-Masurel and Eftedal-Brubakk scales, respectively. The overall median grade was KM/EB 0.5 and the overall median maximum grade was KM/EB 2. Two cases of transient shoulder discomfort ("niggles") were observed (0.9% (95% CL 0.1% 3.3%)) and were treated with surface oxygen. One dive, for which no bubble measurements were made, resulted in a neurological DCS treated with hyperbaric oxygen. The DCS risk of this profile is below that predicted by models, and comparison of the cumulative incidence of DCS of these data to the large dataset compiled by DCIEM [1, 2], show that the incidence is lower than might be expected.

  • 13. Blogg, SL
    et al.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    The use of ultrasound bubble detection to develop the Swedish Navy trimix dive tables2015Conference paper (Refereed)
  • 14. Blogg, S.L.
    et al.
    Gennser, Mikael
    Swedish Defence Research Agency.
    Loveman, G.A.M.
    Seddon, F.M.
    Thacker, J.C.
    White, M.G.
    The effect of breathing hyperoxic gas during simulated submarine escape on venous gas emboli and decompression illness2003In: Undersea & Hyperbaric Medicine, ISSN 1066-2936, Vol. 30, no 3, p. 163-174Article in journal (Refereed)
    Abstract [en]

    Raised internal pressure in a distressed submarine rapidly increases the risk of decompression sickness (DCS) following submarine escape. The hypothesis that breathing a hyperoxic gas during escape may reduce the risk of DCS was tested using goats. Shallow air saturation and simulated submarine escape dives were carried out either singularly or in combination (saturation, escape, or saturation followed by escape) using air or 60% / 40% oxygen (O2) / nitrogen (N2) mixture as breathing gas during the escapes. Post-surfacing, animals were observed for signs of DCI and O2 toxicity. Precordial Doppler ultrasound was used to score venous gas emboli (VGE) using the Kisman Masurel (KM) scale. Following escape from 2.5 MPa, the rate at which VGE disappeared in the hyperoxic group (n = 8) was significantly faster(p < 0.05) than the air group (n = 7). One case of pulmonary barotrauma with arterial gas embolism occurred in the air group, but no cases of DCS were observed. After saturation at 0.18 MPa followed by escape from 2.5 MPa, DCS occurred in four of 15 animals in the air group and in two of 16 animals in the hyperoxic group. The rate of disappearance of VGE was significantly faster (p < 0.01) in the hyperoxic group. O2 toxicity was not discernible in any of the animals.

  • 15. Blogg, S.L.
    et al.
    Loveman, G.A.
    Seddon, F.M.
    Woodger, N.
    Koch, A.
    Reuter, M.
    Gennser, Mikael
    Swedish Defence Research Agency.
    White, M.G.
    Magnetic resonance imaging and neuropathology findings in the goat nervous system following hyperbaric exposures2004In: European Neurology, ISSN 0014-3022, E-ISSN 1421-9913, Vol. 52, no 1, p. 18-28Article in journal (Refereed)
    Abstract [en]

    Divers may be at risk of long-term CNS damage from non-symptomatic hyperbaric exposure. We investigated the effect of severe, controlled hyperbaric exposure on a group of healthy goats with similar histories. Thirty goats were exposed to various dive profiles over a period of 5 years, with 17 experiencing decompression sickness (DCS). Brains were scanned using magnetic resonance (MR) imaging techniques. The animals were then culled and grossly examined, with the brain and spinal cord sent for neuropathological examination. No significant correlation was found between age, years diving, DCS or exposure to pressure with MR-detectable lesions in the brain, or with neuropathological lesions in the brain or spinal cord. However, spinal scarring was noted in 3 animals that had suffered from spinal DCS.

  • 16. Blogg, SL
    et al.
    Møllerløkken, A
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Response: car wrecks and caution: a lament on getting the facts straight in scientific reporting.2017In: Undersea Hyperb Med, Vol. 44, p. 492-494Article in journal (Other (popular science, discussion, etc.))
  • 17.
    Eiken, Ola
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Grönkvist, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Kabintryck och risk för barotrauma vid explosiv decompression I fpl 392015Report (Other academic)
  • 18.
    Frånberg, Oskar
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Dödsfall i samband med dykning med återandningsapparater: ett människa–maskin interaktionsproblem2013In: Hygiea, 2013Conference paper (Refereed)
    Abstract [sv]

    Huvuddelen av de rapporterade och undersökta olyckorna med återandningsapparater utlöstes av felaktigt handhavande, eller bristande människa–maskininteraktion.

  • 19.
    Frånberg, Oskar
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Measurement and modeling of oxygen content in a demand mass ratio injection rebreather2015In: Undersea & Hyperbaric Medicine, ISSN 1066-2936, Vol. 42, no 6, p. 573-592Article in journal (Refereed)
    Abstract [en]

    Mechanical semi-closed rebreathers do not need oxygen sensors for their functions, thereby reducing the complexity of the system. However, testing and modeling are necessary in order to determine operational limits as well as the decompression obligation and to avoid hyperoxia and hypoxia. Two models for predicting the oxygen fraction in a demand constant mass ratio injection (DCMRI) rebreather for underwater use were compiled and compared. The model validity was tested with an IS-MIX, Interspiro AB rebreather using a metabolic simulator connected to a breathing machine inside a water-filled pressure chamber. The testing schedule ranged from 0.5-liter (L) to 3-liter tidal volumes, breathing frequencies from five to 25 breaths/minute and oxygen consumptions from 0.5 L/minute to 4 L/minute. Tests were carried out at surface and pressure profiles ranging to 920 kPa(a) (81 meters of sea water, 266 feet of sea water). The root mean squared error (RMSE) of the single-compartment model was 2.4 percent-units of oxygen for the surface test with the 30% dosage setting but was otherwise below 1% unit. For the multicompartment model the RMSE was below 1% unit of oxygen for all tests. It is believed that these models will aid divers in operational settings and may constitute a helpful tool when developing semi-closed rebreathing apparatuses.

  • 20.
    Frånberg, Oskar
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Modeling a demand constant volume ratio exhaust and a self-mixing constant oxygen injection semi-closed rebreatherManuscript (preprint) (Other academic)
    Abstract [en]

    Unmanned tests of two types of gas dosage techniques for semi-closed underwater rebreathing apparatuses were carried out with a metabolic simulator in a water filled pressure chamber. Tests were conducted over a wide range of tidal volumes (0.5-3 L), respiratory frequencies (5-25 min-1), and oxygen consumptions (0.5-4 L/min), as well as with changing chamber pressures from 100 kPa to 920 kPa. Two models were set up, one single compartment model and one model assuming multiple serial compartments. Both models seem to have about the same level of accuracy at predicting the inspired oxygen levels at pressure, but the surface tests seem to favor the serial compartments model.

  • 21.
    Frånberg, Oskar
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Oxygenandningsapparat med nitroxväxlingsmöjlighet.2010Report (Other academic)
  • 22.
    Frånberg, Oskar
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Linden, J.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Evaluating a simplified purge procedure for oxygen/nitrox switch rebreathers2011Conference paper (Refereed)
  • 23.
    Frånberg, Oskar
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Loncar, Mario
    Larsson, Ake
    Örnhagen, Hans
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    A Metabolic Simulator for Unmanned Testing of Breathing Apparatuses in Hyperbaric Conditions2014In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 85, no 11, p. 1139-1144Article in journal (Refereed)
    Abstract [en]

    Background: A major part of testing of rebreather apparatuses for underwater diving focuses on the oxygen dosage system. Methods: A metabolic simulator for testing breathing apparatuses was built and evaluated. Oxygen consumption was achieved through catalytic combustion of propene. With an admixture of carbon dioxide in the propene fuel, the system allowed the respiratory exchange ratio to be set freely within human variability and also made it possible to increase test pressures above the condensation pressure of propene. The system was tested by breathing ambient air in a pressure chamber with oxygen uptake (VO2) ranging from 1-4 L.min(-1), tidal volume (V-T) from 1-3 L, breathing frequency (f) of 20 and 25 breaths/min, and chamber pressures from 100 to 670 kPa. Results: The measured end-tidal oxygen concentration (FO2) was compared to calculated end-tidal FO2. The largest average difference in end-tidal FO2 during atmospheric pressure conditions was 0.63%-points with a 0.28%-point average difference during the whole test. During hyperbaric conditions with pressures ranging from 100 to 670 kPa, the largest average difference in FO2 was 1.68%-points seen during compression from 100 kPa to 400 kPa and the average difference in FO2 during the whole test was 0.29%-points. Conclusion: In combination with a breathing simulator simulating tidal breathing, the system can be used for dynamic continuous testing of breathing equipment with changes in V-T, f, VO2, and pressure.

  • 24.
    Frånberg, Oskar
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Loncar, Mario
    Larsson, Åke
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Örnhagen, Hans
    Metsim, ett hjälpmedel för att testa slutna andningsapparater på ett fysiologiskt sätt2013In: Hygiea, 2013Conference paper (Refereed)
    Abstract [sv]

    Valet av propen som bränsle och de tekniska svårigheter som övervanns för att skapa en säker ämnesomsättningssimulator som kan användas vid tester i tryck motsvarande 100 m dykdjup.

  • 25.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Application of ultrasound techniques in diving research: Use of bubble detection to develop trimix tables for Swedish mine-clearance divers and evaluating trimix decompressions2015Conference paper (Refereed)
  • 26.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Jämförelse mellan två olika slussystem för djup FU från ubåt2011Report (Other academic)
  • 27.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Kolmonoxidnivåer i ubåtsatmosfär2011Report (Other academic)
  • 28.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Luftkvalitet för BIBS- och HIS-gas2011Report (Other academic)
  • 29.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Environmental Physiology.
    PM angående Trimixdyk med IS-Mix vid Søværnets dykerskole, maj 20112011Report (Other academic)
  • 30.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    PM avseende resultat av provdykningar med OMD10 (IS-MIX) vid DN under våren 2016.2016Report (Other academic)
  • 31.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Problems with introducing the new USN air diving tables for the Swedish Navy.2016Conference paper (Refereed)
  • 32.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Submarine escape physiology2013Conference paper (Refereed)
  • 33.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Testing of decompression tables and use of decompression algorithms: a pragmatic view2014Conference paper (Refereed)
  • 34.
    Gennser, Mikael
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Trimix tables for semi-closed mechanical rebreather: IS-Mix2013Conference paper (Refereed)
  • 35.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Bergh, Ulf
    Metoder för effektivare utprovning av dekompressionstabeller för dykning2011Conference paper (Refereed)
  • 36.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Blogg, L
    Effect of gas switch on decompression from trimix dives2015Conference paper (Refereed)
  • 37.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Blogg, L
    Venous gas bubble load after trimix dives using electronic closed circuit rebreathers2014Conference paper (Refereed)
  • 38.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology. KTH, School of Technology and Health (STH), Centres, Swedish Aerospace Physiology Centre, SAPC.
    Blogg, L
    Eiken, Ola
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology. KTH, School of Technology and Health (STH), Centres, Swedish Aerospace Physiology Centre, SAPC.
    Jaki Mekjavic, P
    Mekjavic, IB
    Comparison of venous bubbles and tear film bubbles after decompression during a five week 6° head-down tilt bed rest2015Conference paper (Refereed)
  • 39.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Blogg, L.
    Eiken, Ola
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Mekjavic, I.
    Comparison between mild dehydration and body temperature on decompression bubble formation2010Conference paper (Refereed)
  • 40.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Blogg, L.
    Frånberg, Oskar
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Bubble recordings after nitrox dives with a semi-closed demand controlled rebreather2011Conference paper (Refereed)
  • 41.
    Gennser, Mikael
    et al.
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Environmental Physiology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Swedish Aerospace Physiology Centre, SAPC.
    Blogg, S. L.
    SLB Consulting, Newbiggin On Lune, Cumbria, England..
    Eiken, Ola
    KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Biomedical Engineering and Health Systems, Environmental Physiology. KTH, School of Engineering Sciences in Chemistry, Biotechnology and Health (CBH), Centres, Swedish Aerospace Physiology Centre, SAPC.
    Mekjavic, Igor B.
    Jozef Stefan Inst, Dept Automat Biocybernet & Robot, Ljubljana, Slovenia.;Simon Fraser Univ, Dept Biomed Physiol & Kinesiol, Burnaby, BC, Canada..
    Indices of Increased Decompression Stress Following Long-Term Bed Rest2018In: Frontiers in Physiology, ISSN 1664-042X, E-ISSN 1664-042X, Vol. 9, article id 442Article in journal (Refereed)
    Abstract [en]

    Human extravehicular activity (EVA) is essential to space exploration and involves risk of decompression sickness (DCS). On Earth, the effect of microgravity on physiological systems is simulated in an experimental model where subjects are confined to a 6 degrees head-down bed rest (HDBR). This model was used to investigate various resting and exercise regimen on the formation of venous gas emboli (VGE), an indicator of decompression stress, post-hyperbaric exposure. Eight healthy male subjects participating in a bed rest regimen also took part in this study, which incorporated five different hyperbaric exposure (HE) interventions made before, during and after the HDBR. Interventions i-iv were all made with the subjects lying in 6 degrees HD position. They included (C1) resting control, (C2) knee-bend exercise immediately prior to HE, (T1) HE during the fifth week of the 35-day HDBR period, (C3) supine cycling exercise during the HE. In intervention (C4), subjects remained upright and ambulatory. The HE protocol followed the Royal Navy Table 11 with 100 min spent at 18 m (280 kPa), with decompression stops at 6 m for 5 min, and at 3 m for 15 min. Post-HE, regular precordial Doppler audio measurements were made to evaluate any VGE produced post-dive. VGE were graded according to the Kisman Masurel scale. The number of bubbles produced was low in comparison to previous studies using this profile [Kisman integrated severity score (KISS) ranging from 0-1], and may be because subjects were young, and lay supine during both the HE and the 2 h measurement period post-HE for interventions i-iv. However, the HE during the end of HDBR produced significantly higher maximum bubble grades and KISS score than the supine control conditions (p < 0.01). In contrast to the protective effect of pre-dive exercise on bubble production, a prolonged period of bed rest prior to a HE appears to promote the formation of post-decompression VGE. This is in contrast to the absence of DCS observed during EVA. Whether this is due to a difference between hypo- and hyperbaric decompression stress, or that the HDBR model is a not a good model for decompression sensitivity during microgravity conditions will have to be elucidated in future studies.

  • 42.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Blogg, Samantha L.
    Venous Gas Emboli in Goats After Simulated Submarine Escape from 290 msw Breathing Air or Hyperoxic Gas2009In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 80, no 11, p. 927-932Article in journal (Refereed)
    Abstract [en]

    GENNSER M, BLOGG. SL. Venous gas emboli in goats after simulated submarine escape from 290 msw breathing air or hyperoxic gas. Aviat Space Environ Med 2009; 80:927-32. Introduction: Escape from a disabled submarine has many inherent risks. Including the development of venous gas emboli (VGE) Breathing hyperoxic gas during rapid ascent from 2500 kPa (240 msw) reduces VGE, we Investigated whether it would also be beneficial during all escape from 3000 kPa (290 msw), thought to be at the limit of escape from a sunk sub Methods: Adult castrated male or female goats (45-85 kg, N = 35) Underwent dry chamber compression to 3000 kPa in 28 s, then decompressed at a rate of 2 75 m . s(-1) while breathing either air or hyperoxic gas (60/40%. O-2/N-2) Postsurfacing, precordial Doppler measurements were made using the Kisman Masurel (KM) scoring system, the animals were observed for signs of decompression illness (DCI) and/or oxygen toxicity Results: Six animals in the air group (N = 19) and two in the hyperoxic group (N = 10) suffered from severe I)pulmonary barotrauma on surfacing and were euthanized No cases of DO arose later than 5 min postsurfacing. Oxygen toxicity was not observed Although initial bobble Scores (median KM score 4) were the same in both groups, the time taken for the median KM score to reach 3 or less was significantly faster in the hyperoxic group (20 min vs 120 min) Disappearance of VGE was faster in the hyperoxic group Conclusion: Breathing hyperoxic gas during escape from 3000 kPa reduces the overall time. With circulating VGE and, despite exposure to a maximum inspired partial pressure, of oxygen of 1 8 MPa, symptoms of oxygen toxicity were not observed

  • 43.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Blogg, SL
    Bubble scores after diving according to the new USNavy air decompression tables.2017Conference paper (Refereed)
  • 44.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Blogg, SL
    Effekt av gasbyte på dekompressionshastighet efter korta trimix dykningar2015Conference paper (Refereed)
  • 45.
    Gennser, Mikael
    et al.
    Swedish Defence Research Agency.
    Blogg, S.L.
    Oxygen or carbogen breathing before simulated submarine escape2008In: Journal of applied physiology, ISSN 8750-7587, E-ISSN 1522-1601, Vol. 104, no 1, p. 50-56Article in journal (Refereed)
    Abstract [en]

    Raised internal pressure in a distressed submarine increases the risk of bubble formation and decompression illness after submarine escape. The hypothesis that short periods of oxygen breathing before submarine escape would reduce decompression stress was tested, using Doppler-detectable venous gas emboli as a measure. Twelve goats breathed oxygen for 15 min at 0.1 MPa before exposure to a simulated submarine escape profile to and from 2.5 MPa (240 m/seawater), whereas 28 control animals underwent the same dive without oxygen prebreathe. No decompression sickness (DCS) occurred in either of these two groups. Time with high bubble scores (Kisman-Masurel >or=3) was significantly (P < 0.001) shorter in the prebreathe group. In a second series, 30 goats breathed air at 0.2 MPa for 6 h. Fifteen minutes before escape from 2.5 MPa, animals were provided with either air (n = 10), oxygen (n = 12), or carbogen (97.5% O(2) and 2.5% CO(2)) gas (n = 8) as breathing gas. Animals breathed a hyperoxic gas (60% O(2)-40% N(2)) during the escape. Two animals (carbogen group) suffered oxygen convulsions during the escape but recovered on surfacing. Only one case of DCS occurred (carbogen group). The initial bubble score was reduced in the oxygen group (P < 0.001). The period with bubble score of Kisman-Masurel >or=3 was also significantly reduced in the oxygen group (P < 0.001). Oxygen breathing before submarine escape reduces initial bubble scores, although its significance in reducing central nervous system DCS needs to be investigated further.

  • 46.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Blogg, SL
    Douglas, J
    Kvarnström, A
    Oscarsson, N
    Rosén, A
    Påverkar oxygenandning direkt efter dykning bubbelförekomst?2015Conference paper (Refereed)
  • 47.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Blogg, S.L.
    Jurd, K.
    Pre-dive exercise and post-dive evolution of gas emboli2011In: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448Article in journal (Other academic)
  • 48.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Basic Science and Biomedicine, Environmental Physiology.
    Douglas, J
    High resolution chest CT: Findings with possible bearing on risk for pulmonary barotrauma2013Conference paper (Refereed)
  • 49.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Eiken, Ola
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Effekter av exponering för måttlig hypoxi vid vistelse i brandsäkrat arbetsutrymme.2011Report (Other academic)
  • 50.
    Gennser, Mikael
    et al.
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Frånberg, Oskar
    KTH, School of Technology and Health (STH), Environmental Physiology.
    Maximala dyktider för direktuppstigning med FM återandningssystem2012Report (Other academic)
12 1 - 50 of 79
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf