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  • 1.
    Frånberg, Oskar
    Swedish Defence Research Agency.
    Anordning och förfarande för att producera oxygen: Device and method for producing oxygen2005Patent (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    The invention relates to a medical device for producing oxygen, wherein the device comprises means for providing first conditions, and means for changing said first conditions to second conditions, the device being configured to during a charging phase extract oxygen from air by, under said first conditions, bringing said air (A) into contact with an agent (SfF) constituted by a reversibly oxygen-fixating agent, i.e. an oxygen selective material, such that the oxygen of the air is adsorbed by said agent, and to remove nitrogen under said first conditions, and configured to during a discharging phase release the oxygen from the agent by means of changing said first conditions to said second conditions. The invention also relates to a method for producing oxygen for individual medical purposes.

  • 2.
    Frånberg, Oskar
    Swedish Defence Research Agency.
    Breathing apparatus1999Patent (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    A breathing apparatus is described, having a breathing circuit comprising a mouthpiece (8) and one or more gas carrying conduits (60), a compressed gas source (2) and a counterlung (5). The compressed gas source (2) is in communication with the counterlung (5) via the breathing circuit. The counterlung (5) has an expansion assisting means (3) and a contraction assisting means (20), and a control allows selective activation of the expansion assisting means (3) and the contraction assisting means (20). The counterlung has primary (12) and secondary (10) chambers, and inflation of the secondary chamber (10) causes inflation of the primary chamber (12). The expansion assisting means (3) is a flow of compressed gas to inflate the secondary chamber (10).

  • 3.
    Frånberg, Oskar
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Oxygen content in semi-closed rebreathing apparatuses for underwater use: Measurements and modeling2015Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The present series of unmanned hyperbaric tests were conducted in order to investigate the oxygen fraction variability in semi-closed underwater rebreathing apparatuses. The tested rebreathers were RB80 (Halcyon dive systems, High springs, FL, USA), IS-Mix (Interspiro AB, Stockholm, Sweden), CRABE (Aqua Lung, Carros Cedex, France), and Viper+ (Cobham plc, Davenport, IA, USA). The tests were conducted using a catalytically based propene combusting metabolic simulator. The metabolic simulator connected to a breathing simulator, both placed inside a hyperbaric pressure chamber, was first tested to demonstrate its usefulness to simulate human respiration in a hyperbaric situation. Following this the metabolic simulator was shown to be a useful tool in accident investigations as well as to assess the impact of different engineering designs and physiological variables on the oxygen content in the gas delivered to the diver by the rebreathing apparatuses. A multi-compartment model of the oxygen fractions was developed and compared to the previously published single-compartment models. The root mean squared error (RMSE) of the multi-compartment model was smaller than the RMSE for the single-compartment model, showing its usefulness to estimate the impact of different designs and physiological variables on the inspired oxygen fraction.

  • 4.
    Frånberg, Oskar
    Swedish Defence Research Agency.
    Rechargeable breathing apparatus particularly an apparatus for divers2000Patent (Annet (populærvitenskap, debatt, mm))
    Abstract [en]

    A rechargeable breathing apparatus with a closed breathing system, particularly for aqua-diver. It comprises a breathing bellows (28) for reception of the exhaled air, to which bellows a pressurised container (38) for a gas or a mixture of gases is connected through a hydrostatic valve (42). The breathing bellows is arranged, after adsorption of CO2 from the exhaled air, and oxygen supply, to deliver breathing air to the diver. An oxygen accumulator (12) containing a reversibly oxygen fixating agent is connected to the breathing bellows (28). The oxygen accumulator (12) is rechargeable by bringing said agent into reaction with oxygen gas or oxygen in the air whereby the oxygen is adsorbed to the same. An oxygen accumulator (12) upon heating gives off oxygen to the breathing bellows. The apparatus may also be used during smoke divin

  • 5.
    Frånberg, Oskar
    et al.
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Ericsson, M.
    Larsson, Å.
    Lindholm, P.
    Investigation of a Halcyon RB80 semiclosed rebreather in connection with a diving accident2010Konferansepaper (Fagfellevurdert)
  • 6.
    Frånberg, Oskar
    et al.
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Ericsson, Mikael
    Larsson, Agneta
    Lindholm, Peter
    Investigation of a demand-controlled rebreather in connection with a diving accident2011Inngår i: Undersea & Hyperbaric Medicine, ISSN 1066-2936, Vol. 38, nr 1, s. 61-72Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This paper describes the examination of a Halcyon RB80 semi-closed underwater breathing apparatus used in a diving accident in 2007. The apparatus was supplied with trimix (oxygen, nitrogen and helium) containing 31% oxygen. The duration of the dive was 105 minutes at 28 meters' average depth in fresh water, with a 19-minute oxygen decompression stop at 6 meters. Upon surfacing the diver experienced seizures and signs of severe neurological deficits. The apparatus was tested with regard to the oxygen fraction drop from the supply gas to the breathing loop - i.e., the oxygen fraction inhaled by the diver (FiO2) was investigated. The FiO2 was measured and found to be lower than the value stated on the manufacturer's web page at the time of the accident. This investigation suggests that during the dive, the actual FiO2% was 17.9-25.3%, which is considerably lower than the FiO2% used for decompression calculations (30%). The underestimation of FiO2 resulted in too short and/or too few decompression stops during ascent. The low FiO2 would also put a diver at risk of hypoxia at shallow depths. It is concluded that inadequate information on the performance of the rebreather was a major contributing factor to this accident.

  • 7.
    Frånberg, Oskar
    et al.
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Gennser, Mikael
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Dödsfall i samband med dykning med återandningsapparater: ett människa–maskin interaktionsproblem2013Inngår i: Hygiea, 2013Konferansepaper (Fagfellevurdert)
    Abstract [sv]

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

  • 8.
    Frånberg, Oskar
    et al.
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Gennser, Mikael
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Measurement and modeling of oxygen content in a demand mass ratio injection rebreather2015Inngår i: Undersea & Hyperbaric Medicine, ISSN 1066-2936, Vol. 42, nr 6, s. 573-592Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 9.
    Frånberg, Oskar
    et al.
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Gennser, Mikael
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Modeling a demand constant volume ratio exhaust and a self-mixing constant oxygen injection semi-closed rebreatherManuskript (preprint) (Annet vitenskapelig)
    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.

  • 10.
    Frånberg, Oskar
    et al.
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Gennser, Mikael
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Oxygenandningsapparat med nitroxväxlingsmöjlighet.2010Rapport (Annet vitenskapelig)
  • 11.
    Frånberg, Oskar
    et al.
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Linden, J.
    Gennser, Mikael
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Evaluating a simplified purge procedure for oxygen/nitrox switch rebreathers2011Konferansepaper (Fagfellevurdert)
  • 12.
    Frånberg, Oskar
    et al.
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Loncar, Mario
    Larsson, Ake
    Örnhagen, Hans
    Gennser, Mikael
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    A Metabolic Simulator for Unmanned Testing of Breathing Apparatuses in Hyperbaric Conditions2014Inngår i: Aviation, Space and Environmental Medicine, ISSN 0095-6562, E-ISSN 1943-4448, Vol. 85, nr 11, s. 1139-1144Artikkel i tidsskrift (Fagfellevurdert)
    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.

  • 13.
    Frånberg, Oskar
    et al.
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Loncar, Mario
    Larsson, Åke
    Gennser, Mikael
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Örnhagen, Hans
    Metsim, ett hjälpmedel för att testa slutna andningsapparater på ett fysiologiskt sätt2013Inngår i: Hygiea, 2013Konferansepaper (Fagfellevurdert)
    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.

  • 14.
    Frånberg, Oskar
    et al.
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Silvanus, M
    Rebreather technology and practical tests2014Konferansepaper (Fagfellevurdert)
  • 15.
    Gennser, Mikael
    et al.
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Blogg, L.
    Frånberg, Oskar
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Bubble recordings after nitrox dives with a semi-closed demand controlled rebreather2011Konferansepaper (Fagfellevurdert)
  • 16.
    Gennser, Mikael
    et al.
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Frånberg, Oskar
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Maximala dyktider för direktuppstigning med FM återandningssystem2012Rapport (Annet vitenskapelig)
  • 17.
    Gennser, Mikael
    et al.
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Frånberg, Oskar
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Blogg, S. L
    Dekompressionsbelastning vid trimixdykning: Jämförelse mellan dykning med konstant fraktion och konstant partialtryck oxygen2014Konferansepaper (Fagfellevurdert)
    Abstract [sv]

    Bakgrund: Användning av trimixgas (O2, N2, och He) tillåter dykning till större djup än med luft eller nitrox. Trots att den här dyktekniken blir alltmer populär bland sk ”tekniska dykare” så visar de få vetenskapliga rapporter som publicerats att trimixdykning ger upphov till rikligt med bubblor i den venösa cirkulationen (Ljubkovic et al 2010). Den här studien genomfördes för att undersöka venös bubbelförekomst efter dykning med konstant oxygenpartialtryck (PO2). Jämförelse gjordes med tidigare mätningar med konstant oxygenfraktion.

    Metoder: Sex försvarsmaktsdykare och en instruktör deltog i dykningar med sluten återandningsapparat där PO2 kontrollerades elektroniskt (eCCR). Dykningarna genomfördes med trimixgas till djup mellan 20 – 100 m. I de flesta fall hölls PO2 konstant vid 1,3 atm. Dekompressionsprofilerna beräknades med VPM-B algoritm. Förekomst av venösa gasbubblor detekterades med hjälp av ultraljuds-Doppler. Mängden bubblor skattades med Kisman-Masurel skalan (KM). Resultaten jämfördes med trimixdykningar (33 – 60 m) som genomförts i våt tryckkammare, men en halvsluten dykapparat som gav dykarna en konstant oxygenfraktion (FO2 27%). Dekompressionerna i dessa dykningar beräknades med en DCAP-algoritm.

     Resultat: Bubbelförekomst hos de 7 dykarna som använde eCCR undersöktes efter totalt 133 dykningar. Ingen bubbelpoäng över KM 3 uppmättes vid något dyk. Sammanlagt 92 dykningar genomfördes med den halvslutna apparaten. Bubbelpoängen i dessa dykningar varierade mellan 0 – 4 (16% av dykningarna >KM III). Efter upprepade dykningar till 70 m med eCCR var median bubbelpoängen KM 2 (n = 11).

    Slutsats: Djupa trimixdykningar med konstant PO2 och dekompressioner beräknade med VPM-B gav upphov till lägre maximal bubbelförekomst än dykningar med konstant oxygenfraktion.

  • 18.
    Gennser, Mikael
    et al.
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Frånberg, Oskar
    KTH, Skolan för teknik och hälsa (STH), Naturvetenskap och biomedicin, Omgivningsfysiologi.
    Blogg, Samantha L.
    SLB Consulting, Cumbria, Storbritannien.
    Jämförelse mellan olika dekompressionstabeller med hjälp av ultraljudsdoppler2013Inngår i: Hygiea, 2013Konferansepaper (Fagfellevurdert)
    Abstract [sv]

    Två dekompressionstabeller, en med sk djupa stopp, jämfördes avseende förekomst av bubblor i den centralvenösa cirkulationen. Tabellen med ortodox algoritm orsakade betydligt färre bubblor.

  • 19. Larsson, Agneta
    et al.
    Uusijärvi, Johan
    Frånberg, Oskar
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi.
    Eksborg, Staffan
    Lindholm, Peter
    Nitrox permits direct exit for attendants during extended hyperbaric oxygen treatment2012Inngår i: Undersea & Hyperbaric Medicine, ISSN 1066-2936, Vol. 39, nr 1, s. 605-612Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Background: Intermittent breathing of oxygen-enriched air, nitrox (1:1 air:oxygen, 60.5%O-2), for attendants in multiplace hyperbaric chambers should enable treatment protocols (HOPAN hyperbaric oxygen protocol attendants' nitrox) of up to 200 minutes at 2.8 atmospheres absolute (ATA), while retaining the option of a direct decompression and exit.Methods: HOPAN with cycles of 15 minutes of nitrox breathing followed by 10 minutes of chamber air for attendants were occasionally used from 2007-2009. HOPAN vs. LTP (local treatment protocols) were evaluated via an anonymous enquiry among attendants; patients' medical records were followed six months post-HBO2 treatment (HBO2T).Results: 88 HOPANs, with 59 chamber attendants assisting 30 patients, were documented. HOPAN duration ranged from 55-167 minutes (median 140 minutes). 31/59 attendants answered the enquiry. Perceived comfort of each protocol (HOPAN vs. LTP) by attendants was reported as equal. Symptoms, both minor (parestesias) and severe (joint pain), were reported in connection with LTP, while only one occurrence (mild joint pain) was reported in connection with HOPAN. No complications were documented among the attendants or the patients. It is suggested that nitrox breathing for chamber attendants provide flexible HBO2T for patients at 2.8 ATA for up to 200 minutes within no-decompression limits, facilitating future studies of HBO2T dosage.

  • 20. Lindholm, Peter
    et al.
    Boberg, Olle
    Frånberg, Oskar
    KTH, Skolan för teknik och hälsa (STH), Omgivningsfysiologi (Stängd 20130701).
    Larsson, Åke
    Gullstrand, Lennart
    Intermittent oxygen inhalation increase maximal workload and maximal heart rate in elite athletes2013Inngår i: The FASEB Journal, ISSN 0892-6638, E-ISSN 1530-6860, Vol. 27Artikkel i tidsskrift (Annet vitenskapelig)
1 - 20 of 20
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