Individualized System for Augmenting Ventilator Efficacy (iSAVE): A Rapidly deployable system to expand ventilator capacity

Shriya Srinivasan; Khalil Ramadi; Franceso Vicario; Declan Gwynne; Alison Hayward; Robert Langer; Joseph Frassica; Rebecca Baron; Giovanni Traverso

A Philips critical care ventilator was utilized for testing as representative of closed-circuit ventilators typically used in the ICU. The iSAVE is designed to work with virtually any closed-circuit ventilators currently found in ICUs. Y-connectors were connected to the inspiratory and expiratory limbs of the ventilator to enable individual channels for each lung. In the inspiratory limbs, the following components were connected in series: 1) a bacterial/viral filter (Main Flow Bacterial/Viral Filter, Teleflex Medical), 2) ball valve (EKWB G ¼'' Nickel, Microcenter), 3) one-way valve (a Threshold PEP positive expiratory pressure device, Philips, was used as a surrogate for one-way valves), 4) pressure sensor, 5) flow sensor, and 6) capnostat adaptor. In the expiratory limb, the following components were connected in series: 1) a bacterial/viral filter, 2) a pressure release valve (PEEP valve), and 3) an optional one-way valve prior to connection with the ventilator (Threshold PEP). PTFE tubing was used to adapt the ball valves to the standard 22mm outer diameter corrugated flex tubing. A dual adult lung simulator (Model 5600i, Michigan Instruments) was used to perform simulations with the closed-circuit ventilator. Pressure and flow were displayed and recorded by the Philips NM3 monitors and associated sensors, one for each channel.