Yale students 3D-printed a $250 valve box so one ventilator could serve two patients

Fast Company reported in April 2020 that Yale undergraduates Brian Beitler and Tim Foldy-Porto developed the Vent Multiplexor, a device that lets one ventilator treat two people according to each patient's needs. Distributed by Vent Multiplexor, LLC, it was the first of its kind to receive emergency FDA authorization, after co-ventilating two critically ill COVID-19 patients at Yale New Haven Hospital. Others had tried sharing ventilators, including Prisma Health's VESper, which splits one ventilator among up to four patients, and a hospital protocol using simple tubing.

Yale resident Peter Kahn, the company's medical director, explained that T- or Y-shaped adapters work like a garden hose splitter, so both patients must be on exactly the same settings and be matched by severity. Lung capacities and recovery times differ, and sharing breathed air can pass infections. The Vent Multiplexor connects outside the ventilator, with four one-way valves that can be adjusted manually to put two patients on different settings; high-efficiency filters trap contaminants if the valves fail.

The device costs $250, installs in minutes and is marketed as disposable, against a ventilator price of $50,000 or more. Company president Todd Higgins described the development as a race against time.

Put four manually adjustable one-way valves in an outside circuit, so shared ventilators can serve each patient differently.

Buying more ventilators was costly and slow, so a $250 add-on was cheaper than acquiring more.

Separate valves allow each patient's settings to be tuned, which a Y-splitter cannot do.

Filters limit shared infections if a valve fails.

The device can be 3D-printed and installed quickly.

A copy of the standard fix (a splitter) can have a hidden constraint; add control at the interface instead of changing the expensive machine.

As of the April 2020 report the device was in production after a few weeks of development and testing, with the FDA emergency authorisation and two patients co-ventilated at Yale New Haven. Sterilising and reusing it was possible in theory but not tested, and no wider usage figures were given.