Portable Oxygen Concentrator Research Articles

A translational study evaluating a ruggedized portable oxygen concentrator versus an oxygen cylinder in simulated polytrauma intubation of swine.

Portable oxygen concentrators (POCs) are medical devices that use filters to selectively remove nitrogen from ambient air to produce concentrated, medical-grade oxygen. This is the first study to evaluate a ruggedized POC's performance during simulated polytrauma intubation. Twenty-seven swine were intubated and anesthetized with ketamine. At T=0, animals were extubated, received a chest wall injury, a tibia fracture, and 20% total blood volume controlled hemorrhage was initiated. At T=10 min, the swine were pre-oxygenated using a bag-valve mask connected to one of three randomized oxygen sources: (1) a ruggedized POC, (2) a M-15 oxygen cylinder, or (3) room air (control). At T=12 min, animals were re-intubated to simulate polytrauma intubation and connected to the test oxygen source for the remainder of the experiment. Surviving animals entered a 2-h period where partial pressure of oxygen (PaO2), oxygen saturation (SpO2), and regional oxygen saturation (rSO2) were monitored. Groups were compared using analysis of variance (ANOVA), Fisher's exact, log-rank analysis, or mixed-effects model as appropriate. All animals survived except one in the POC group. Mixed-effects models revealed differences between groups with regards to PaO2 (p<0.0001) and SpO2 (p=0.006). Based on post hoc analysis, oxygen cylinder PaO2 was superior to both POC and control, but there were no differences between POC and control PaO2. There were statistically and clinically significant differences in SpO2 during periods of pre-oxygenation (T=10‒12 min), intubation (T=12‒14 min), and immediately after intubation (T=14‒20 min). The POC battery was consumed in 43±13 min. In our swine model, a single, ruggedized POC provided inferior amounts of oxygen supplementation compared to an oxygen cylinder and performed no better than room air.

Randomized crossover trial of a demand oxygen delivery system in nocturnal hypoxemia

The newly developed portable oxygen concentrator with an auto-demand oxygen delivery system (auto-DODS) automatically switches between 3 sensitivities according to the negative pressure gradient of inhalation and supplies oxygen only during inhalation. The aim of this study was to verify the effectiveness and safety of auto-demand devices compared with a continuous flow oxygen concentrator, during sleep, in a randomized crossover noninferiority trial. We alternatively used an auto-DODS or a continuous-flow oxygen concentrator, all night on separate days for HOT (Home Oxygen Therapy) patients with nocturnal hypoxemic symptoms. The primary endpoints were the mean value of oxygen saturation (SpO2) over the total sleep time. The secondary endpoints included the efficacy endpoints and the safety endpoints. Regarding the primary endpoint, the difference in SpO2 between the auto-DODS and continuous flow was 0.835%. Since the upper limit of this difference did not exceed 2.8, which was set as the noninferiority margin, it was shown that the auto-DODS did not reduce SpO2 by at least 2.8% on average compared to continuous flow. No equipment failure or exacerbation of disease was observed, confirming the safety of the auto-DODS during the night.

Health and Economic Impact of Different Long-Term Oxygen Therapeutic Strategies in Patients with Chronic Respiratory Failure: A French Nationwide Health Claims Database (SNDS) Study.

Long-term oxygen therapy (LTOT) is reported to improve survival in patients with chronic respiratory failure. We aimed to describe effectiveness, burden, and cost of illness of patients treated with portable oxygen concentrators (POC) compared to other LTOT options. This retrospective comparative analysis included adult patients with chronic respiratory insufficiency and failure (CRF) upon a first delivery of LTOT between 2014 and 2019 and followed until December 2020, based on theFrench national healthcare database SNDS. Patients using POC, alone or in combination, were compared with patients using stationary concentrators alone (aSC), or compressed tanks (CTC) or liquid oxygen (LO2), matched on the basis of age, gender, comorbidities, and stationary concentrator use. Among 244,719 LTOT patients (mean age 75 ± 12, 48% women) included, 38% used aSC, 46% mobile oxygen in the form of LO2 (29%) and POC (18%), whereas 9% used CTC. The risk of death over the 72-month follow-up was estimated to be 13%, 15%, and 12% lower for patients in the POC group compared to aSC, CTC, and LO2, respectively. In the POC group yearly mean total costs per patient were 5% higher and 4% lower compared to aSC and CTC groups, respectively, and comparable in the LO2 group. The incremental cost-effectiveness ratio (ICER) of POC was €8895, €6288, and €13,152 per year of life gained compared to aSC, CTC, and LO2, respectively. Within the POC group, we detected an association between higher mobility (POCs autonomy higher than 5h), improved survival, lower costs, and ICER - €6 238, compared to lower mobility POCs users.

Measuring flow rate and purity in portable oxygen concentrators

For people with respiratory disorders who need additional oxygen therapy, oxygen concentrators are vital medical equipment. By concentrating oxygen from the ambient air, they function to give the user a greater flow of oxygen-enriched air. The application of lithium zeolite for oxygen concentration in POCs is the most intense part of this work. One kind of zeolite material that may selectively absorb nitrogen from the air to increase oxygen concentration is lithium zeolite. The capacity, effectiveness, and dependability of a POC fitted with lithium zeolite are all examined in this study, along with its overall performance. The findings show that lithium zeolite, which has benefits including high oxygen purity and low energy consumption, is a potential material for use in POCs. The results of this study aid in the creation of POCs for oxygen therapy that are more effective and efficient. This study suggests utilizing an Arduino microcontroller and an HX710B air pressure sensor to measure the oxygen flow rate in a POC. The POC’s oxygen flow channel incorporates the HX710B sensor to monitor pressure variations, which the Arduino uses to translate into flow rate readings. To verify the accuracy and dependability of the system, its performance is assessed under different flow rate scenarios. Lithium zeolites are well-known for having a high selectivity for nitrogen adsorption, which can enhance the concentrator’s oxygen separation process’s effectiveness. Lithium-zeolite-based oxygen concentrators may have a lower environmental effect than standard concentrators.

Improving Breath Detection From Pulsed-Flow Oxygen Sources Using a New Nasal Interface.

Patients with COPD and other lung diseases are treated with long-term oxygen therapy (LTOT). Portable oxygen sources are required to administer LTOT while maintaining patient autonomy. Existing portable oxygen equipment has limitations that can hinder patient mobility. A novel nasal interface is presented in this study, aiming to enhance breath detection and triggering efficiency of portable pulsed-flow oxygen devices, thereby improving patient mobility and independence. To examine the effectiveness of the new interface, 8 respiratory therapists participated in trials using different oxygen sources (tank with oxygen-conserving device, SimplyGo Mini portable oxygen concentrator [POC], and OxyGo NEXT POC) and breathing types (nasal and oral) while using either the new nasal interface or a standard cannula. Each trial was video recorded so participant breaths could be retroactively matched with a pulse/no-pulse response, and triggering success rates were calculated by dividing the number of oxygen pulses by the number of breaths in each trial. After each trial, volunteers were asked to rate their perceived breathing resistance. Nasal breathing consistently resulted in higher triggering success rates compared to oral breathing for pulsed-flow oxygen devices. POCs exhibited higher triggering success rates than did the oxygen tanks with conserving device. However, there were no significant differences in triggering success rates between the two POC models. The new nasal interface demonstrated improved triggering success rates compared to the standard cannula. Whereas the new nasal interface was associated with a slight increase in perceived breathing resistance during nasal breathing trials, participants reported manageable resistance levels when using the interface. This study demonstrates that the new nasal interface can improve triggering success rates of pulsed-flow oxygen devices during both nasal and oral breathing scenarios. Further research involving patient trials is recommended to understand the clinical implications of improved pulse triggering.

Patient Use Patterns of Portable Oxygen Concentrators.

Portable oxygen concentrators (POCs) are medical devices that provide supplemental oxygen to patients requiring long-term oxygen therapy. However, little information is available on day-to-day patterns of how or even whether patients actively switch between their POC mobility features and flow setting options. A retrospective analysis was conducted to assess POC usage among patients who used an Inogen One G5 POC in the USA. This study aimed (1) to describe the patterns of use of POCs, (2) to analyze their compatibility with the prescribed oxygen therapy settings, and (3) to demonstrate the contribution of POC usage to get a standardized long-term oxygen therapy (LTOT). Data were directly downloaded from the devices returned for service or at the end of the Medicare Durable Medical Equipment rental period and streamed via a mobile application from 2018 to 2022. Daily usage, disconnections from the device, use of prescribed pulse delivery settings, breaths per minute, power sources, and movement with the POC were assessed. Device alert histories were also examined. Data revealed a mean daily usage of 4.29 ± 3.23h/day, ranging from 0.35 to 15.52h/day. The prescribed pulse delivery setting was used by 31.34% of patients for at least 80% of their POC use time. When the POC was on battery power, patients were moving/mobile 41.99 ± 33.33% of the time. On the basis of the device-generated alerts, some patients continued to use their POC very close to or even beyond the lifetime of the column/sieve bed. Alerts or alarms potentially requiring repair occurred at a rate of 1.63 events per 100years of use, indicating that device reliability did not significantly influence the use patterns. Patients used their POCs when mobile and at rest. A large proportion of patients adjust their POC settings during the day, which potentially indicates the need for the dynamic individualization of oxygen dose delivery to match activities of daily living or sleep. Patients require follow-up to ensure timely replacement of POC columns.

A Novel CPAP Device With an Integrated Oxygen Concentrator for Low Resource Countries: In Vitro Validation and Usability Test in Field.

Goal: To develop and validatea novel neonatal non-invasive respiratory support device prototype designed to operate in low-resource settings. Methods: The device integrates a blower-based ventilator and a portable oxygen concentrator. A novel control algorithm was designed to achieve the desired fraction of inspired oxygen (FiO2) while minimizing power consumption. The accuracy of the delivered FiO2 and the device power consumption were evaluated in vitro, and a formative usability test was conducted in a rural hospital in Uganda. Results: The agreement between the set and delivered FiO2 was high (limit of agreement:-5.6 ÷ 3.8%). For FiO2 below 60%, the control algorithm reduced the power drain by 50%. The device was also appreciated by intended users. Conclusion: The prototype proved effective in delivering oxygen-enriched continuous positive airway pressure in the absence of compressed air and oxygen, holding promise for a sustainable and effective implementation of neonatal respiratory support in low-resource settings.

Development of Portable Oxygen Concentrator - A Review

The Covid-19 Pandemic, with its first ever reported case in the Wuhan province of China in the year 2019, has led to a newfound global demand for Medical Oxygen supply at a sudden and unprecedented rate. In India, people battled to breathe as oxygen demand shot up with a sudden surge in COVID-19 cases the year 2020. The additional requirement of oxygen was tried to be fulfilled by various means such as oxygen generators installed at hospitals, transported medical as well as Industrial liquid oxygen, oxygen cylinder and oxygen concentrator. During the Covid-19 outbreak, large crowds gathered outside hospitals, and many patients were treated at home, breathing with the assistance of an oxygen concentrator and cylinders. However, cylinders must be refilled, whereas unlimited supply of medical grade oxygen can be obtained by oxygen concentrator if a power backup is maintained. In addition to this, safety, cost and size are the additional features of oxygen concentrator. It is a boon for the sufferer at the initial stage or even after treatment of covid-19, which is made available anywhere. In this paper, an attempt has been made to study an oxygen concentrator in which the principle of Pressure Swing Adsorption (PSA) method is used for oxygen separation. In addition to this, some trends of recently evolved developments in oxygen concentration methods are also reviewed for the readers’ reference. This effort will help to develop the oxygen concentrator to fulfill the demand of oxygen at local level during the waves of Covid or similar incidences in future.

Evaluation of Over-the-Counter Portable Oxygen Concentrators Utilizing a Metabolic Simulator.

Supplemental oxygen is designed to raise alveolar PO2 to facilitate diffusion into arterial blood. Oxygen is generally delivered by nasal cannula either by continuous or pulsatile flow. Battery-powered portable oxygen concentrators (POCs) facilitate ambulation in patients experiencing exertional hypoxemia. In the United States, the Food and Drug Administration (FDA) clears these devices to be sold by physician prescription. Recently, however, lower-cost devices described as POCs have been advertised by online retailers. These devices lack FDA clearance and are obtained over the counter (OTC) without prescription. This study determined whether a selected group of OTC POCs have oxygen delivery characteristics suitable for use by hypoxemic patients. A metabolic simulator, capable of simulating a range of metabolic rates and minute ventilations, determined effects of oxygen supplementation delivered by a variety of devices on alveolar PO2 . Devices tested included 3 OTC POCs, an FDA-cleared POC, and continuous-flow oxygen from a compressed oxygen cylinder. End-tidal PETO2 , a surrogate of alveolar PO2 , was determined at each of each device's flow settings at 3 metabolic rates. Continuous-flow tank oxygen yielded a linear PETO2 increase as flow increased, with progressively lower slope of increase for higher metabolic rate. The prescription POC device yielded similar PETO2 elevations, though with somewhat smaller elevations in pulse-dose operation. One OTC POC was only technically portable (no on-board battery); it provided only modest PETO2 elevation that failed to increase as flow setting was incremented. A second OTC POC produced only minimal PETO2 elevation. A third OTC POC, a pulsed-dose device, produced meaningful PETO2 increases, though not as great as the prescription device. Only one of 3 OTC POCs tested was potentially of use by patients requiring ambulatory oxygen. Physicians and respiratory therapists should inform patients requiring portable oxygen that OTC devices may not meet their oxygenation requirements.

Control of the Purity of 93% Oxygen Obtained from the Air by Pressure Swing Adsorption

The assessment of the quality of 93% oxygen obtained from the air by pressure swing adsorption (PSA) presents an important challenge for applied research. Such an assessment provides a possibility to guarantee the safety of oxygen therapy using both stationary and portable PSA-based oxygen concentrators. In this article, the experts of the Scientific Centre for Expert Evaluation of Medicinal Products and S.M. Kirov Military Medical Academy offer their recommendations for the implementation of monograph 2.2.0037.22 Oxygen (93 per cent) in civil healthcare organisations or military medical units. The publication of this monograph, which was approved by order No. 126 issued by the Ministry of Health of the Russian Federation on 01.03.2022, became the endpoint of the experts’ cooperation aimed at the inclusion of 93% oxygen into the Russian State Register of Medicinal Products.

Growth of home respiratory equipment from 2006 to 2019 and cost control by health policies

BackgroundHome respiratory equipment (HRE) designed for the management of chronic respiratory failure includes oxygen therapy (O2), noninvasive ventilation (NIV) and mechanical insufflation-exsufflation (MI-E). The growth of the number of patients treated by HRE, the prevalence and the associated costs in France have not been determined. MethodsThe French open access national health insurance aggregated data was used to estimate the evolution of theses parameters from 2006 to 2019. ResultsThe number of patients treated by HRE increased by 117% between 2006 and 2019, reaching a total of 245,896 patients (367/100,000). Prescriptions for O2, NIV, and MI-E increased by 88%, 189% and 162%, respectively. In 2019, 139,323 patients received long-term home O2 alone (208/100,000) with a 13% decrease for liquid O2 compared to a 44% increase for O2 concentrator. The number of patients treated by portable oxygen concentrator increased by 509% over the last 5 years. In 2019, 96,126 patients received NIV (144/100,000) and 97% of these patients were treated by NIV for less than 12 h/day. A total of 9,158 patients were treated by MI-E in 2019 (13.6/100,000). Despite the global increase in the number of patients, health costs decreased from 9% to 8% of total medical device spending in 2019 due to adjustment of health policies, such as a reduction of reimbursement rates. ConclusionOur results highlighted the high rate of HRE prescription, but with cost control as a result of adapted health policies.

The Use of Portable Oxygen Concentrators in Low-Resource Settings: A Systematic Review.

Portable oxygen concentrators (POCs) are medical devices that use physical means to separate oxygen from the atmosphere to produce concentrated, medical-grade gas. Providing oxygen to low-resources environments, such as austere locations, military combat zones, rural Emergency Medical Services (EMS), and during disasters, becomes expensive and logistically intensive. Recent advances in separation technology have promoted the development of POC systems ruggedized for austere use. This review provides a comprehensive summary of the available data regarding POCs in these challenge environments. PubMed, Google Scholar, and the Defense Technical Information Center were searched from inception to November 2021. Articles addressing the use of POCs in low-resource settings were selected. Three authors were independently involved in the search, review, and synthesis of the articles. Evidence was graded using Oxford Centre for Evidence-Based Medicine guidelines. The initial search identified 349 articles, of which 40 articles were included in the review. A total of 724 study subjects were associated with the included articles. There were no Level I systematic reviews or randomized controlled trials. Generally, POCs are a low-cost, light-weight tool that may fill gaps in austere, military, veterinary, EMS, and disaster medicine. They are cost-effective in low-resource areas, such as rural and high-altitude hospitals in developing nations, despite relatively high capital costs associated with initial equipment purchase. Implementation of POC in low-resource locations is limited primarily on access to electricity but can otherwise operate for thousands of hours without maintenance. They provide a unique advantage in combat operations as there is no risk of explosive if oxygen tanks are struck by high-velocity projectiles. Despite their deployment throughout the battlespace, there were no manuscripts identified during the review involving the efficacy of POCs for combat casualties or clinical outcomes in combat. Veterinary medicine and animal studies have provided the most robust data on the physiological effectiveness of POCs. The success of POCs during the coronavirus disease 2019 (COVID-19) pandemic highlights the potential for POCs during future mass-casualty events. There is emerging technology available that combines a larger oxygen concentrator with a compressor system capable of refilling small oxygen cylinders, which could transform the delivery of oxygen in austere environments if ruggedized and miniaturized. Future clinical research is needed to quantify the clinical efficacy of POCs in low-resource settings.

Maximizing Oxygen Delivery in Portable Ventilators.

Military transport of critically ill/injured patients requires judicious use of resources. Maintaining oxygen (O2) supplies for mechanically ventilated is crucial. O2 cylinders are difficult to transport due to the size and weight and add the risk of fire in an aircraft. The proposed solution is the use of a portable oxygen concentrator (POC) to supply O2 for mechanical ventilation. As long as power is available, a POC can provide an endless supply of O2. Anecdotal evidence suggests that as little as 3 L/min of O2 could manage as many as 2/3 of the mechanically ventilated military aeromedical transport patients. We evaluated two each of the AutoMedx SAVe II, Hamilton T1, Zoll 731, and Ventec VOCSN portable ventilators over a range of settings paired with 1 and 2 Caire SAROS POCs at ground level and simulated altitudes of 8,000 feet, 16,000 feet, and 22,000 feet. The Ventec VOCSN has the capability of utilizing an internal O2 concentrator that uses pulsed dose technology, which was also evaluated. Each ventilator was attached to a Michigan Instruments Training Test Lung. Output from the POC was bled into each ventilator via the mechanism provided with each device. A Fleisch pneumotach was used to measure delivered tidal volume (VT), and a fast-response O2 analyzer was used to measure FiO2 within the simulated lung. Ventilator parameters and FiO2 were continuously measured and recorded at each altitude. One-way analysis of variance was used to determine statistically significant differences (P < .05) in FiO2 between ventilators and among the same ventilator model at each testing condition. Delivered FiO2 varied widely between ventilator models and between devices of the same model with some testing conditions. Differences in FiO2 between ventilators at a majority (98.5%) of testing conditions were statistically significant (P < .05) but not all were clinically important. The Zoll 731 delivered the highest and most consistent FiO2 over all ventilator/POC settings at all altitudes. Differences in FiO2 at a given ventilator/POC setting from ground level to 22,000 feet were not clinically important (<5%) with this device. The VOCSN utilizing the integrated internal O2 concentrator delivered the lowest FiO2 across all ventilator/POC settings and altitudes. Due to the inability of the SAVe II to operate at the minute ventilation and positive end expiratory pressure (PEEP) settings required by the testing protocol, the device was only tested at one ventilator setting. The Hamilton T1 failed to operate appropriately at the highest VT/PEEP setting at 16,000 feet and all but one ventilator setting at 22,000 feet. The delivered FiO2 was not included in the analysis for those ventilator settings. The highest delivered FiO2 was 0.85 ± 0.05 at the 250 mL VT setting using 2 POCs (P < .0001) at ground level with the Zoll 731. Oxygen delivery utilizing POCs is dependent upon multiple factors including ventilator operating characteristics, ventilator settings, altitude, and the use of pulsed dose or continuous flow O2. Careful patient selection would be paramount to provide safe mechanical ventilation using this method of O2 delivery.

In Vitro Evaluation of a Nasal Interface Used to Improve Delivery From a Portable Oxygen Concentrator

Abstract Portable oxygen concentrators (POCs) are widely used to administer long-term oxygen therapy (LTOT) and employ pulsed delivery modes to conserve oxygen. Efficient pulsed delivery requires that POCs are triggered by patient inhalation. Triggering is known to fail for some patients during periods of quiet breathing, as occurs during sleep. This article describes a new nasal interface designed to improve triggering of pulsed oxygen delivery from POCs. In vitro experiments incorporating realistic nasal airway replicas and simulated breathing were conducted. The pressure monitored via oxygen supply tubing (the signal pressure) was measured over a range of constant inhalation flow rates with the nasal interface inserted into the nares of the nasal airway replicas, and then compared with signal pressures measured for standard and flared nasal cannulas. The triggering efficiency and fraction of inhaled oxygen (FiO2) were next evaluated for the nasal interface and cannulas used with a commercial POC during simulated tidal breathing through the replicas. Higher signal pressures were achieved for the nasal interface than for nasal cannulas at all flow rates studied. The nasal interface triggered pulsed delivery from the POC in cases where nasal cannulas had failed to do so. FiO2 was significantly higher for successful triggering cases than for failed triggering cases. The nasal interface improved triggering of pulsed oxygen delivery from a POC and presents a simple solution that could be used with commercially available POCs to reliably supply oxygen during periods of quiet breathing.

Multi‐disciplinary collaborative consensus guidance statement on the assessment and treatment of breathing discomfort and respiratory sequelae in patients with post‐acute sequelae of SARS‐CoV‐2 infection (PASC)

<scp>Multi‐disciplinary</scp> collaborative consensus guidance statement on the assessment and treatment of breathing discomfort and respiratory sequelae in patients with <scp>post‐acute</scp> sequelae of <scp>SARS‐CoV</scp>‐2 infection (<scp>PASC</scp>)

Experimental study of an oil-free swing vane compressor

Conventional compressors must always be operated in the upright orientation to ensure that the oil sump is always located at the lowest position to allow the collection of lubricant back to the oil sump by gravity. As a result, conventional compressors are not suitable for applications where orientation-free and portability of the system are required. Applications such as wearable cryogenic cooling bags for the ease of vaccine transportation, compact cryogenic coolers for space applications or even as a portable oxygen concentrator (POC) for ambulatory patients will not be feasible with current compressors. A direct solution would be to eliminate the need for oil lubrication in the operation of a compressor. This would require a successful development of an oil-free compressor. In this work, an oil-free swing vane compressor prototype was designed, instrumented and tested. Its performance was evaluated with air and R134a as working fluids. For experiments with air at 1080 to 1800 rev min−1, pressure ratios of up to 4.08 with mechanical and volumetric efficiencies ranging from 22.0% to 40.0% and 30.9% to 67.5% were obtained, respectively. For experiment with R134a at 1620 rev min−1, the prototype has achieved mechanical and volumetric efficiencies of 45.1% and 55.5%, respectively, with a coefficient of performance (COP) of 1.25. Potential failure modes of this oil-free compressor have been identified and recommendations for design improvement are also presented in this study.

A Novel Ventilator Design for COVID-19 and Resource-Limited Settings

There has existed a severe ventilator deficit in much of the world for many years, due in part to the high cost and complexity of traditional ICU ventilators. This was highlighted and exacerbated by the emergence of the COVID-19 pandemic, during which the increase in ventilator production rapidly overran the global supply chains for components. In response, we propose a new approach to ventilator design that meets the performance requirements for COVID-19 patients, while using components that minimise interference with the existing ventilator supply chains. The majority of current ventilator designs use proportional valves and flow sensors, which remain in short supply over a year into the pandemic. In the proposed design, the core components are on-off valves. Unlike proportional valves, on-off valves are widely available, but accurate control of ventilation using on-off valves is not straightforward. Our proposed solution combines four on-off valves, a two-litre reservoir, an oxygen sensor and two pressure sensors. Benchtop testing of a prototype was performed with a commercially available flow analyser and test lungs. We investigated the accuracy and precision of the prototype using both compressed gas supplies and a portable oxygen concentrator, and demonstrated the long-term durability over 15 days. The precision and accuracy of ventilation parameters were within the ranges specified in international guidelines in all tests. A numerical model of the system was developed and validated against experimental data. The model was used to determine usable ranges of valve flow coefficients to increase supply chain flexibility. This new design provides the performance necessary for the majority of patients that require ventilation. Applications include COVID-19 as well as pneumonia, influenza, and tuberculosis, which remain major causes of mortality in low and middle income countries. The robustness, energy efficiency, ease of maintenance, price and availability of on-off valves are all advantageous over proportional valves. As a result, the proposed ventilator design will cost significantly less to manufacture and maintain than current market designs and has the potential to increase global ventilator availability.

State of the art review on portable oxygen concentrator

State of the art review on portable oxygen concentrator

Burden and Unmet Needs with Portable Oxygen in Patients on Long-Term Oxygen Therapy.

Rationale: Over 1.5 million Americans receive long-term oxygen therapy (LTOT) for the treatment of chronic hypoxemia to optimize functional status and quality of life. However, current portable oxygen equipment, including portable gas tanks (GTs), portable liquid tanks (LTs), and portable oxygen concentrators (POCs), each have limitations that can hinder patient mobility and daily activities. Objectives: To examine patient experiences with portable oxygen to guide equipment innovation and thereby improve patient care on oxygen therapy. Methods: The burden and unmet needs with portable oxygen equipment were assessed in 836 LTOT patients with chronic lung disease (chronic obstructive pulmonary disease [COPD], interstitial lung disease, and pulmonary hypertension) through an online survey. The survey included a combination of multiple-choice, Likert-scale, short-answer, and open-ended questions. Distribution was achieved through patient support organizations, including the U.S. COPD Coalition, the Pulmonary Fibrosis Foundation, and the Pulmonary Hypertension Association. Results: Improvements in portability were ranked as the highest priority by patients across all equipment types, followed by increases in the duration of oxygen supply for GTs, accessibility for LTs, and flow capabilities for POCs. All device types were found to be burdensome, with the greatest burden among GT users, 51% of whom characterized GT use as "strenuous" or "extremely strenuous" (high burden). POCs ranked as the most common (61%) and least burdensome devices; however, 29% of POC users still reported a high associated burden. Forty-seven percent of POC respondents described using a POC despite it not meeting their oxygen needs to benefit from advantages over alternative equipment. Among non-POC users, limited oxygen flow rate capabilities and cost were the top reasons preventing POC use. Conclusions: Although improvements have been made to portable oxygen equipment, this study highlights the burden that remains and reveals a clear need for advances in technology to improve the functional status and quality of life of portable LTOT users.

Ambulatory oxygen for treatment of exertional hypoxaemia in pulmonary fibrosis (PFOX trial): a randomised controlled trial

IntroductionInterstitial lung diseases are characterised by scarring of lung tissue that leads to reduced transfer of oxygen into the blood, decreased exercise capacity and premature death. Ambulatory oxygen therapy may...