Low Oxygen Flow Rate Research Articles

Oxygenation and Carbon Dioxide Rebreathing of a Well-fitting Non-rebreathing EcoLite™ Mask with a Reservoir: A Single-center Prospective Observational Study in Healthy Volunteers.

The fitting of oxygen mask affects the performance of it such as oxygenation or CO₂ elimination. The intersurgical EcoLite™ adult high-concentration oxygen mask (EcoLite with a reservoir, Intersurgical, UK) was developed to give well-fitting. The purpose of this study is to evaluate the performance of EcoLite with a reservoir compared to the conventional mask. Ten healthy volunteers were included in this study. EcoLite with a reservoir and conventional mask were given to patients at different oxygen flow rates (5, 8, 10, 12, and 15 L/min). Fraction of inspiratory O₂ (FIO₂) and partial pressure of inspiratory CO₂ (PICO₂) were measured by a sampling tube at the middle pharynx inserted via nose. The EcoLite with a reservoir had a significantly higher FIO₂ than the control reservoir mask. However, the PICO₂ was significantly higher in the EcoLite with a reservoir than in the control reservoir mask, especially when the oxygen flow rate was low. The EcoLite with a reservoir provided improved oxygenation and a better fit than the conventional reservoir masks in healthy volunteers. However, the EcoLite with a reservoir might cause higher CO₂ rebreathing at low oxygen flow rates.

Pharyngeal oxygen delivery device sustains manikin lung oxygenation longer than high-flow nasal cannula

Purpose Hypoxemia during a failed airway scenario is life threatening. A dual-lumen pharyngeal oxygen delivery device (PODD) was developed to fit inside a traditional oropharyngeal airway for undisrupted supraglottic oxygenation and gas analysis during laryngoscopy and intubation. We hypothesized that the PODD would provide oxygen as effectively as high-flow nasal cannula (HFNC) while using lower oxygen flow rates. Methods We compared oxygen delivery of the PODD to HFNC in a preoxygenated, apneic manikin lung that approximated an adult functional residual capacity. Four arms were studied: HFNC at 20 and 60 liters per minute (LPM) oxygen, PODD at 10 LPM oxygen, and a control arm with no oxygen flow after initial preoxygenation. Five randomized 20-minute trials were performed for each arm (20 trials total). Descriptive statistics and analysis of variance were used with statistical significance of P < 0.05. Results Mean oxygen concentrations were statistically different and decreased from 97% as follows: 41 ± 0% for the control, 90 ± 1% for HFNC at 20 LPM, 88 ± 2% for HFNC at 60 LPM, and 97 ± 1% (no change) for the PODD at 10 LPM. Conclusion Oxygen delivery with the PODD maintained oxygen concentration longer than HFNC in this manikin model at lower flow rates than HFNC.

True intratracheal oxygen concentration delivered by SentriO Oxy™ masks under various respiratory conditions: a bench study

SentriO Oxy™ is a newly available, Food and Drug Administration-approved oxygenation mask system that provides high oxygenation, even on low-flow (5–10 L/min) oxygen. This study aimed to accurately measure the intratracheal fraction of inspired oxygen (FiO2) using SentriO Oxy™ masks under relatively low oxygen flow rates. A manikin-ventilator-test lung simulation system was used. We measured FiO2 at the level of the carina, 5 minutes after applying 45 different respiratory parameter combinations using SentriO Oxy™ masks. Tidal volume (TV) was set to 300, 500, and 700 mL; respiratory rate (RR) was set to 8, 12, 16, 20, and 24 breaths per minute; and oxygen flow rate was set to 6, 8, and 10 L/min. Our hypothesis was that FiO2 would be proportional to the difference between oxygen flow rate and minute ventilation. FiO2 measured by smaller TV, lower RR, or higher oxygen flows revealed a significantly higher value, confirming our hypothesis. In addition, using linear regression analysis, we found that TV, RR, and oxygen flow were all significant factors influencing the measured FiO2. Our experiment proposed two prediction equations considering the oxygen flow rate, TV, and RR. The results of our study may provide information and prediction of FiO2 for clinicians to use SentriO Oxy™ masks during sedative anesthetic procedures under low oxygen flow rates.

Development of carbon-based metal free electrochemical sensor for hydrogen peroxide by surface modification of carbon nanowalls

A novel metal-free amperometric sensor based on O2/Ar plasma modified carbon nanowalls (CNW) was successfully developed for non-enzymatic detection of hydrogen peroxide (H2O2).This study demonstrates the effectiveness of surface modification of CNW by O2/Ar plasma treatment to improve the electrochemical sensing performance. It was shown that the CNW treated in low oxygen flow rate (O2/Ar: 0.1/10sccm) exhibited the highest concentration of incorporated oxygen on its structure, which consequently resulted in conversion of intrinsic hydrophobicity of CNW to hydrophilicity. Interestingly, however, further increase in oxygen flow rate did not increase the oxygen content of CNW structure, but instead it resulted in an increment in the defect and contributing less oxygen on CNW surface. The highest amperometric response was observed for the CNW treated with O2/Ar: 1.0/10sccm, which has lower oxygen content than the CNW treated with O2/Ar: 0.1/10sccm, but still possessing hydrophilic characteristic as well as owning more defect sites. These results can suggest the importance of both defects and oxygen-containing functional groups in electrochemical behavior of the electrode as both defects and oxygen-containing functional groups can act as potential active sites for electrochemical reactions and oxygen-containing functional groups can enhance the hydrophilicity and surface area wetted by the electrolyte. The modified CNW exhibited the potential for quantification analysis of H2O2 with a wide linear range covering from 50 μM to 28000 μM, a good sensitivity of 126.6 μA/mM.cm2 and a detection limit of 0.91 μM (S/N = 3). This study demonstrates the success in utilizing the CNW structure towards detecting of H2O2 as a metal-free sensor.

Data automated bag breathing unit for COVID-19 ventilator shortages

BackgroundThe COVID-19 pandemic has caused a global mechanical ventilator shortage for treatment of severe acute respiratory failure. Development of novel breathing devices has been proposed as a low cost, rapid solution when full-featured ventilators are unavailable. Here we report the design, bench testing and preclinical results for an 'Automated Bag Breathing Unit' (ABBU). Output parameters were validated with mechanical test lungs followed by animal model testing.ResultsThe ABBU design uses a programmable motor-driven wheel assembled for adult resuscitation bag-valve compression. ABBU can control tidal volume (200–800 ml), respiratory rate (10–40 bpm), inspiratory time (0.5–1.5 s), assist pressure sensing (− 1 to − 20 cm H2O), manual PEEP valve (0–20 cm H2O). All set values are displayed on an LCD screen. Bench testing with lung simulators (Michigan 1600, SmartLung 2000) yielded consistent tidal volume delivery at compliances of 20, 40 and 70 (mL/cm H2O). The delivered fraction of inspired oxygen (FiO2) decreased with increasing minute ventilation (VE), from 98 to 47% when VE was increased from 4 to 16 L/min using a fixed oxygen flow source of 5 L/min.ABBU was tested in Berkshire pigs (n = 6, weight of 50.8 ± 2.6 kg) utilizing normal lung model and saline lavage induced lung injury. Arterial blood gases were measured following changes in tidal volume (200–800 ml), respiratory rate (10–40 bpm), and PEEP (5–20 cm H2O) at baseline and after lung lavage. Physiological levels of PaCO2 (≤ 40 mm Hg [5.3 kPa]) were achieved in all animals at baseline and following lavage injury. PaO2 increased in lavage injured lungs in response to incremental PEEP (5–20 cm H2O) (p < 0.01). At fixed low oxygen flow rates (5 L/min), delivered FiO2 decreased with increased VE.ConclusionsABBU provides oxygenation and ventilation across a range of parameter settings that may potentially provide a low-cost solution to ventilator shortages. A clinical trial is necessary to establish safety and efficacy in adult patients with diverse etiologies of respiratory failure.

Superiority of OxyMaskTM with less carbon dioxide rebreathing in children.

Despite the growing importance of oxygen-delivery devices worldwide, there are only a few reports of physiological data on various oxygen masks in children. The possibility of carbon dioxide (CO2) rebreathing has been a prevalent concern with the use of oxygen-delivery devices. OxyMask KidTM (Southmedic Inc. Canada; hereafter OxyMask) is expected to reduce CO2 rebreathing even at low oxygen flow rates because of its structural features. Biological data using OxyMask in children have not been well investigated. Measured respiratory parameters of OxyMask with those of a simple oxygen mask in healthy children were compared. Ten subjects were enrolled, with a median age of 5.4 years. All subjects used both OxyMask and a simple oxygen mask. The fraction of inspiratory oxygen (FIO2), partial pressure of inspiratory CO2 (PICO2), and partial pressure of end-tidal CO2 were measured using a sidestream gas-sampling monitor in all subjects. The oxygen flow rate was set at 1, 3, 5, and 10 L/min. FIO2 levels were higher with OxyMask than those with the simple oxygen mask at 3 L/min of oxygen. PICO2 levels were significantly lower with OxyMask than those with the simple oxygen mask (1.5 mmHg vs. 3.7 mmHg at 1 L/min, P = 0.005; 1.0 mmHg vs. 2.7 mmHg at 3 L/min, P = 0.005, respectively), whereas PICO2 levels were higher at low oxygen flow rates with both masks.Conclusion: Our results showed that higher FIO2 and less CO2 rebreathing were achieved with OxyMask than those with a simple oxygen mask at low flow rates of oxygen in healthy children. What is Known: • OxyMask is expected to reduce carbon dioxide rebreathing even at low oxygen flow rates because of its structural features. • Efficacy has been demonstrated in experimental models and adult data, but clinical data on the use of the OxyMask in children are limited. What is New: • Higher fraction of inspiratory oxygen and lesser carbon dioxide rebreathing were achieved with OxyMask than with a simple oxygen mask at low flow rates of oxygen in healthy children.

Impact of oxygen flow rate on performance of indium-tin-oxide-based RRAMs

This paper investigates the effect of oxygen flow rates on the performance of the resistive random access memory (RRAM) of indium-tin-oxide (ITO)/ITO(O2)/TiN configuration. By using a co-sputtering deposition system with oxygen gas at different flow rates, oxygen-rich ITO thin films, such as the RRAM switching layer, can be realized. The relationship between oxygen flow rates and electrical characteristics is provided in this research. Further, the material analyses indicate that the oxygen exhibits different bonding characteristics. As a result, the device with the lower oxygen flow rate has better electrical characteristics and reliability. In addition, to explain the experimental results, the Schottky emission conduction mechanism for the high-resistance state and the Ohmic conduction mechanism for the low-resistance state are determined through the current fitting results, and appropriate models are proposed.

The variation of FiO2 with circuit type and peak inspiratory flow rate during non-invasive respiratory support using domiciliary ventilators and its significance during the COVID-19 pandemic.

BackgroundThe COVID-19 pandemic has resulted in increased admissions with respiratory failure and there have been reports of oxygen failure and shortages of machines to deliver ventilation and Continuous Positive Airway Pressure (CPAP). Domiciliary ventilators which entrain room air have been widely used during the pandemic. Poor outcomes reported with non-invasive respiratory support using ventilators which lack an oxygen blender could be related to an unreliable Fraction of inspired O2 (FiO2). Additionally, with concerns about oxygen failure, the variety of ventilator circuits used as well as differing peak inspiratory flow rates (PIFR) could impact on the FiO2 delivered during therapy with domiciliary ventilators.MethodsIn a series of bench tests, we tested the effect of choice of circuit and different PIFR on the FiO2 achieved during simulation of ventilation and CPAP therapy using domiciliary ventilators.ResultsFiO2 was highly dependent upon the type of circuit used with circuits with an active exhalation valve achieving similar FiO2 at lower oxygen flow rates than circuits using an exhalation port. During CPAP therapy, high PIFR resulted in significantly lower FiO2 than low PIFR.ConclusionsThis study has implications for oxygen usage as well as delivery of non-invasive respiratory support during therapy with domiciliary ventilators when these are used during the second wave of COVID-19.

Molecular beam epitaxy growth of the highly conductive oxide SrMoO3

SrMoO3 is a promising material for its excellent electrical conductivity, but growing high-quality thin films remains a challenge. Here we synthesized epitaxial films of SrMoO3 using molecular beam epitaxy (MBE) technique under low oxygen-flow rate. Introduction of SrTiO3 buffer layers of 4–8 unit cells between the film and the (0 0 1)-oriented SrTiO3 or KTaO3 substrate was crucial to remove impurities and/or roughness of the film surface. The obtained film shows improved electrical conductivities as compared with films obtained by other techniques. The high quality of the SrMoO3 film is also verified by angle resolved photoemission spectroscopy (ARPES) measurements showing a clear Fermi surface.

Carbon-templated strategy toward the synthesis of dense and yolk-shell multi-component transition metal oxide cathode microspheres for high-performance Li ion batteries

Development of efficient strategies for the synthesis of multicomponent microspheres applicable to cathodes in lithium ion batteries is in urgent need. This paper presents ‘drop and dry’ method for synthesizing dense and yolk-shell multicomponent transition metal oxide microspheres. The infiltration of ethanol solution containing several metal precursors into highly porous carbon template microspheres through repetitive drop and dry process and subsequent heat treatment under oxygen atmosphere result in dense and yolk-shell microspheres. The first target cathode material is LiMn1.5Ni0.5O4, which operates at high voltage. After infiltration of Li, Mn, and Ni salts into the pores of the carbonaceous microspheres, stepwise heat treatment under low oxygen flow rate yields dense LiMn1.5Ni0.5O4 microspheres exhibiting non-aggregation characteristics and narrow size distribution. In comparison, one-step oxidation of carbon microspheres containing metal salts under high oxygen flow rate results in yolk-shell LiMn1.5Ni0.5O4 microspheres. The dense and yolk-shell microspheres exhibit stable cycle performance and capacities of 113 and 111 mA h g−1 are delivered after 1200 cycles at 10 C rate, respectively. In addition, discharge capacities of 69 and 44 mA h g−1 for yolk-shell and dense microspheres, respectively, are delivered at a high current density of 50 C.

Oxy-Fuel Combustion Characteristics of Pulverized Coal under O2/Recirculated Flue Gas Atmospheres

Oxy-fuel combustion is an effective technology for carbon capture and storage (CCS). Oxy-combustion for coal-fired power stations is a promising technology by which to diminish CO2 emissions. Unfortunately, little attention has been paid to the oxy-combustion characteristics affected by the combustion atmosphere. This paper is aimed at investigating the oxy-fuel combustion characteristics of Australian coal in a 0.3 MWth furnace. In particular, the influences of various oxygen flow rates and recirculated flue gas (RFG) on heating performance and pollutant emissions are examined in O2/RFG environments. The results show that with increases in the secondary RFG flow rate, the temperatures in the radiative and convective sections decrease and increase, respectively. At a lower oxygen flow rate, burning Australian coal emits lower residual oxygen and NO concentrations. In the flue gas, a high CO2 concentration of up to 94.8% can be achieved. Compared to air combustion, NO emissions are dramatically reduced up to 74% for Australian coal under oxy-combustion. Note that the high CO2 concentrations in the flue gas under oxy-coal combustions suggest great potential for reducing CO2 emissions through carbon capture and storage.

Niobium Oxide Films Deposited by Reactive Sputtering: Effect of Oxygen Flow Rate.

Reactive sputtering is a versatile technique used to form compact films with excellent homogeneity. In addition, it allows easy control over deposition parameters such as gas flow rate that results in changes on composition and thus in the film required properties. In this report, reactive sputtering is used to deposit niobium oxide films. A niobium target is used as metal source and different oxygen flow rates to deposit niobium oxide films. The oxygen flow rate was changed from 3 to 10 sccm. The films deposited under low oxygen flow rates show higher electrical conductivity and provide better perovskite solar cells when used as electron transport layer.

Iridium oxide catalyst for hybrid electrochromic device based on tetramethylthiourea (TMTU) redox electrolyte

This work reports a study on sputter coated iridium oxide film as a counter electrode (CE) for the electrochemical catalysis of tetramethylthiourea/tetramethylformaminium disulfide (TMTU/TMFDS2+) redox reaction in electrochromic (EC) devices. The iridium oxide (IrOx) with the thickness of about 5 nm coated onto transparent conductive oxide, e.g., fluorine-doped tin oxide (F:SnO2), has shown excellent catalytic properties and excellent electrochromic cycling stability in EC device. The electrochemical impedance spectroscopy (EIS) results revealed that the charge transfer resistance (Rct) is mainly influenced by the oxygen flow rate during the sputtering process, and by the layer thickness. The IrOX films coated with low oxygen flow rate has shown a lower charge transfer resistance compared to the fully oxidized iridium oxide film. However, sub-stoichiometric layers are less transparent, and therefore less appropriate for the application. In this regard, fully oxidized and highly transparent (Tvisible = 86%) layer formed by the sputtering process at or above 50 sccm (standard cubic centimeters per minute) flow of oxygen having the thickness of 5 nm is used in EC devices. These layers have the Rct of 25 Ω cm2 at 1 V bias voltage for the redox electrolytes. The cyclic voltammetry technique has shown a typical quasi-reversible nature of redox electrolyte at the same IrOx coated electrode. An electrochromic test for 550 cycles demonstrates that 5 nm of IrOx is sufficient for the stabile EC window with TMTU/TMFDS2+ electrolyte.

Effects of post combustion temperature on the wear of the supersonic nozzles in BOF lance tip

Abstract This paper studies the influence of post-combustion on supersonic lance tip nozzles wear for an 80t converter, using CFD (Computational Fluid Dynamics) simulations. These analyses were based on flow profile determination of supersonic jet at minimum and maximum operation flow rates, where it could be verified post-combustion inside the nozzles at lowest flow rates. Additionally, thermal input generated by post-combustion was exported as heat flow in order to serve as a boundary condition in CFD thermal exchange simulations, also considering nozzle internal cooling. With these simulations, it was shown that copper actually reaches its melting point, at which the lowest operating flow allows post-combustion inside the nozzle. The temperature distribution profiles and the high temperatures found were also relevant for a considerable grain growth found in the wear region, according to metallographic analyses. It was thus concluded that wear occurs due to the progressive melting of copper after continuous heats with low oxygen flow rates; post-combustion inside the nozzles is the root cause for this failure.

Investigation of HfO2 Thin Films on Si by X-ray Photoelectron Spectroscopy, Rutherford Backscattering, Grazing Incidence X-ray Diffraction and Variable Angle Spectroscopic Ellipsometry

Hafnium oxide (HfO2) thin films have been made by atomic vapor deposition (AVD) onto Si substrates under different growth temperature and oxygen flow. The effect of different growth conditions on the structure and optical characteristics of deposited HfO2 film has been studied using X-ray photoelectron spectroscopy (XPS), Rutherford backscattering spectrometry (RBS), grazing incidence X-ray diffraction (GIXRD) and variable angle spectroscopic ellipsometry (VASE). The XPS measurements and analyses revealed the insufficient chemical reaction at the lower oxygen flow rate and the film quality improved at higher oxygen flow rate. Via GIXRD, it was found that the HfO2 films on Si were amorphous in nature, as deposited at lower deposition temperature, while being polycrystalline at higher deposition temperature. The structural phase changes from interface to surface were demonstrated. The values of optical constants and bandgaps and their variations with the growth conditions were determined accurately from VASE and XPS. All analyses indicate that appropriate substrate temperature and oxygen flow are essential to achieve high quality of the AVD-grown HfO2 films.

Effect of oxygen flow rate and temperature on supersonic jet characteristics and fluid flow in an EAF molten bath

ABSTRACTA new operation method for the oxygen lance of an electric arc furnace (EAF) was proposed, meeting the simultaneous demand for low oxygen flow rate and high stirring power in a particular smelting stage. When the oxygen flow rate needs to be reduced, the stirring power of the jet can be improved by increasing oxygen temperature properly. Free supersonic jet characteristics at different flow rates and stagnation temperatures were studied by numerical simulation and validated by a jet measurement experiment. The results showed that the designed Mach number can be maintained by coupling adjustment of flow rate and stagnation temperature. Meanwhile, a three-phase, full-scaled numerical model for a commercial 75t EAF with three oxygen lances on the side-wall was established to study the fluid flow in the molten bath. The velocity distribution, cavity profile and total kinetic energy of the EAF bath induced by the impingement of supersonic jets onto the liquid bath were discussed and compared. It was found that the fluid flow characteristics of the EAF molten bath can be improved even if the oxygen flow rate was reduced as long as the oxygen temperature could be increased reasonably.

Effects of structure and oxygen flow rate on the photo-response of amorphous IGZO-based photodetector devices

In this study, we investigated how the structure and oxygen flow rate (OFR) during the sputter-deposition affects the photo-responses of amorphous indium-gallium-zinc-oxide (a-IGZO)-based photodetector devices. As the result of comparing three types of device structures with one another, which are a global Schottky diode, local Schottky diode, and thin-film transistor (TFT), the IGZO TFT with the gate pulse technique suppressing the persistent photoconductivity (PPC) is the most promising photodetector in terms of a high photo-sensitivity and uniform sensing characteristic. In order to analyze the IGZO TFT-based photodetectors more quantitatively, the time-evolution of sub-gap density-of-states (DOS) was directly observed under photo-illumination and consecutively during the PPC-compensating period with applying the gate pulse. It shows that the increased ionized oxygen vacancy (VO2+) defects under photo-illumination was fully recovered by the positive gate pulse and even overcompensated by additional electron trapping. Based on experimentally extracted sub-gap DOS, the origin on PPC was successfully decomposed into the hole trapping and the VO ionization. Although the VO ionization is enhanced in lower OFR (O-poor) device, the PPC becomes more severe in high OFR (O-rich) device because the hole trapping dominates the PPC in IGZO TFT under photo-illumination rather than the VO ionization and more abundant holes are trapped into gate insulator and/or interface in O-rich TFTs. Similarly, the electron trapping during the PPC-compensating period with applying the positive gate pulse becomes more prominent in O-rich TFTs. It is attributed to more hole/electron traps in the gate insulator and/or interface, which is associated with oxygen interstitials, or originates from the ion bombardment-related lower quality gate oxide in O-rich devices.

Characterization of n-type Cu2O deposited by reactive ion beam sputter deposition

Cuprous oxide (Cu2O) has been successfully deposited by reactive ion beam sputter deposition at 450 °C with various oxygen flow rates. At high oxygen flow rates, single phase polycrystalline Cu2O thin film was attained while low oxygen flow rates results in the formation of Cu2O nanorods. X-ray diffraction, Raman, and x-ray photoelectron spectroscopy analyses indicate that both samples are composed of Cu2O phase only without the presence of CuO while samples deposited with low oxygen flow rates exhibit improved crystalline quality. Photocurrent measurement result indicates that Cu2O samples prepared under low oxygen flow rate are of n-type. Photoluminescence study suggests that this n-type conductivity is due to the presence of intrinsic oxygen vacancy defects.

Efficiency of oxygen delivery through different oxygen entrainment devices during sedation under low oxygen flow rate: a bench study.

Sedative anesthetic procedures outside the operating room may depend on cylinders as oxygen source. Cylinders have limited storage capacity and a low oxygen flow rate improves the durability. We conducted the bench study to evaluate the fraction of inspired oxygen (FiO2) in different oxygen entrainment devices under low oxygen flow rate. The purpose of the bench study was to provide information to choose appropriate oxygen entrainment devices in non-operating room sedative anesthetic procedures. We utilized a manikin head-test lung-ventilator model and evaluated eight oxygen entrainment devices, including four nasal cannulas, two oral bite blocks, and two masks. Two different minute volumes that defined as the normal ventilation and the hypoventilation group were evaluated. Three pneuflow resistors were placed in turn in the mouth represented ratio of the nasal/oral breathing. Each condition was sampled 70 times after a 3min ventilation period. Most devices had few drop in FiO2 according to the increased oral breathing ratio in normal ventilation. Most devices had obvious drop in FiO2 related to the increased oral breathing ratio in hypoventilation. Oxygen reservoir units had little effect for accumulating oxygen in normal ventilation. In the hypoventilation group, oxygen reservoir units helped oxygen retention in local area and maintained a higher oxygen concentration. There were multiple factors lead to different oxygen fraction that we measured, such as different devices, respiratory patterns, and oxygen reservoir units. The result of our bench study provided some information for anesthesiologist to choose appropriate oxygen entrainment devices in various sedative anesthetic procedures.

Nebulizers and spacers for aerosol delivery through adult nasal cannula at low oxygen flow rate: An in-vitro study

Combining oxygen therapy with aerosol delivery within High flow nasal cannula oxygen therapy (HFNC) is an attractive practice. Delivered dose (DD) was found to decrease with increasing gas flow rates and with smaller sized cannulas. The aim of this study was to quantify amount of aerosol emitted at the cannula outlet using different aerosol generators at low oxygen flow.Aerogen Solo vibrating mesh (SOLO), jet nebulizers, Combihaler connected to metered dose inhaler (MDI) and SOLO, MDI connected AeroChamber Vent and MDI connected AeroChamber Mini were used to deliver aerosol in HFNC in-vitro setting.SOLO with its T-piece delivers DD∼35% of nebulizer charge with high fine-particle-dose (FPD). Both Combihaler and jet-nebulizer delivered∼18% with lower FPD. MDI with both spacers delivers only 2.1 and 1.3% of nominal dose, respectively. Mass median aerodynamic diameters were small for the SOLO, Combihaler and jet nebulizers and high for the two spacers.Inhaled aerosols can be delivered efficiently at low oxygen flow using SOLO, with both T-piece and Combihaler, and jet nebulizer in HFNC system. While MDIs with spacers delivers negligible amounts of drug below that expected for clinical response at this flow.