OxVent: Design and evaluation of a rapidly-manufactured Covid-19 ventilator

Abstract

Background The manufacturing of any standard mechanical ventilator cannot rapidly be upscaled to several thousand units per week, largely due to supply chain limitations. The aim of this study was to design, verify and perform a pre-clinical evaluation of a mechanical ventilator based on components not required for standard ventilators, and that met the specifications provided by the Medicines and Healthcare Products Regulatory Agency (MHRA) for rapidly-manufactured ventilator systems (RMVS). Methods The design utilises closed-loop negative feedback control, with real-time monitoring and alarms. Using a standard test lung, we determined the difference between delivered and target tidal volume (VT) at respiratory rates between 20 and 29 breaths per minute, and the ventilator's ability to deliver consistent VT during continuous operation for >14 days (RMVS specification). Additionally, four anaesthetised domestic pigs (3 male-1 female) were studied before and after lung injury to provide evidence of the ventilator's functionality, and ability to support spontaneous breathing. Findings Continuous operation lasted 23 days, when the greatest difference between delivered and target VT was 10% at inspiratory flow rates > 825 mL/s. In the pre-clinical evaluation, the VT difference was -1 (-90 to 88) mL [mean (LoA)], and positive end-expiratory pressure (PEEP) difference was -2 (-8 to 4) cmH 2 O. VT delivery being triggered by pressures below PEEP demonstrated spontaneous ventilation support. Interpretation The mechanical ventilator presented meets the MHRA therapy standards for RMVS and, being based on largely available components, can be manufactured at scale. Funding Work supported by Wellcome/EPSRC Centre for Medical Engineering,King’s Together Fund and Oxford University.

The development and implementation of a low-cost mechanical ventilator in a low-middle-income country during the COVID-19 pandemic: The Unisabana-HERONS

“…Since the obtention of conventional ventilators was not feasible, and some countries could not access them due to the unavailability of pressurized gas and other socioeconomic barriers, numerous low-cost ventilation devices were developed [ 10 ]. Moreover, since the beginning of the pandemic, different governments worldwide have predicted an imminent shortage of ventilators due to the saturation of the supply chain during the pandemic and competitive priorities [ 11 ]. Some countries even launched initiatives to develop locally produced ventilators at lower prices and with the capacity to scale up their production rapidly.…”

“…Some countries even launched initiatives to develop locally produced ventilators at lower prices and with the capacity to scale up their production rapidly. Therefore, several countries, including the Federal Drug Administration (FDA) in the United States, adjusted their regulatory processes to evaluate and approve the newly developed ventilators, and different initiatives to produce new low-cost ventilators were launched [ 10 , 11 ]. For instance, the Fast-AssembLy COVID-Nineteen (FALCON) ventilator prototype showed promising results on artificial lung models [ 10 ].…”

“…For instance, the Fast-AssembLy COVID-Nineteen (FALCON) ventilator prototype showed promising results on artificial lung models [ 10 ]. Moreover, OxVent accomplished the specifications provided by the Medicines and Healthcare Products Regulatory Agency (MHRA) for rapidly manufactured ventilator systems (RMVS) in artificial lungs and animal models [ 11 ]. It is the same as the ResUHUrge ventilator developed in Spain [ 12 ].…”

Dynamic collaboration in a crisis: creating a low-cost ventilator and test facility

“…All concepts * Author to whom any correspondence should be addressed. at NPL were designed generally in accordance with the UK's MHRA's (Medicines and Healthcare products Regulatory Agency) novel Rapidly Manufactured Ventilator Systems (RMVS) specification [1], which became the de-facto specification for similar systems [2].…”

The HEV Ventilator: at the interface between particle physics and biomedical engineering

“…The Illinois RapidVent [11] ventilator system is an example of a gas-powered pressure-switched design which can be rapidly produced using additive manufacturing at very low component cost; an approach also adopted in other projects [12][13][14]. Another popular design for many groups [15][16][17][18][19][20] is the motor-driven operation of resuscitation bags. These bags are readily available and can be found in all intensive care units (ICUs), where they are routinely used to manually ventilate patients, either intubated or wearing a mask.…”