Rapidly scalable mechanical ventilator for the COVID-19 pandemic.

The SARS-CoV-2 pandemic is straining healthcare systems worldwide, and a global ventilator shortage is fueling the dire situation. As a response, the MIT E-Vent Team (S1) manufactured a scalable ventilator prototype for mass production and demonstrated basic clinical feasibility.

MIT E-Vent engineering information and capabilities, but also missing safety features are provided on the MIT E-Vent website (https://e-vent.mit.edu/) and in the attachments (Fig. 1a, S2). Pressure-based alarms were implemented including in the `Spiro Wave’ device that is based on the MIT E-vent and was just authorized for emergency use by the US FDA. In brief, the MIT E-Vent houses a manual resuscitator, an external compression mechanism, and a control system for adjusting tidal volumes, inspiration-to-expiration ratio, and respiratory rate (Fig. 1a, S3, S4). The MIT E-Vent is equipped with a pressure relief and a positive end-expiratory pressure (PEEP) valve. It delivers unassisted (Fig. 1b) and assisted (not shown) volume control ventilation (VCV). As a proof of concept, a pig was ventilated with the MIT E-Vent or a standard mechanical ventilator (SMV) at distinct settings and arterial blood gases, ventilator waveforms, and flow-volume loops were obtained.

Fig. 1

MIT E-Vent. Prototype design (a). Waveforms and flow-volume loops (b and c). Ventilation (d) and oxygenation testing (e)

The MIT E-Vent performed similar to a SMV at identical respiratory settings. After 36 h of usage including at high demand settings (TV 600 cc, RR 30, PEEP 20), no signs of device failure were noted (S5).

Tidal volume delivery

MIT E-Vent waveforms showed a smooth tidal volume delivery (Fig. 1b). It revealed similar flow-volume loops when compared to manual ventilation using a manual resuscitator (Fig. 1c).

Gas exchange

MIT E-Vent settings were changed to achieve ‘low’ and ‘high’ minute ventilation, and ‘low’ and ‘high’ FiO2 states as reflected in the ABGs (Fig. 1d, e).

The MIT E-Vent provides (un-)assisted VCV, variable MV, and PEEP with airway pressure profiles comparable to a SMV. The MIT E-Vent is not equipped to provide pressure control ventilation (PCV), which may make it unsuitable for awake and the most complex ARDS patients. However, this device is meant as a bridging tool when a conventional ventilator is not available, to serve as ‘destination ventilator device’ in the absence of any alternatives, or to help free up SMV in certain cases.

The MIT E-Vent Team was determined to equip the MIT E-Vent with comprehensive safety features including oxygen and flow sensors, but due to widespread hardware supply shortages, this became impossible. Omitting these safety features was deemed necessary to provide a rapidly scalable prototype. Consequently, increased clinical monitoring is required to provide adequate safety during the use of the MIT E-Vent (S2). Despite these limitations, the MIT-E Vent offers basic mechanical ventilation for selected patients during this ventilator shortage.

The MIT E-Vent Team invites the global community to improve and distribute a version of this scalable, low-cost ventilator during this COVID-19 pandemic.

Oxygenation and ventilation capabilities of a scalable, low-cost ventilator were demonstrated. MIT E-Vent engineering documentation was made public to rapidly implement the MIT E-Vent into the clinical care of patients requiring invasive mechanical ventilation.

Below is the link to the electronic supplementary material.

Supplementary file1 (DOCX 16 kb)

Supplementary file2 (MOV 29738 kb)

Supplementary file3 (MOV 18400 kb)

Supplementary file4 (DOCX 27 kb)