In short. We developed a portable, battery-powered ventilator for a client who needed hospital ventilation modes, closed-loop oxygen mixing, capnography and a hospital network connection in a device you carry by the handle. It was a full-cycle program, from requirements to preclinical testing and production handover. Lisa Voronkova has described it as a ventilator the size of a laptop that other R&D shops had called physically impossible to build.
The challenge
A transport ventilator has to do what an ICU machine does at the weight of a laptop bag. The published envelope is tight: Hamilton Medical lists the T1 at 6.5 kg with 8 hours of battery on two cells, ZOLL lists the EMV+ at 4.4 kg with 10 hours, and Dräger lists the Oxylog 3000 plus at 5.8 kg. Everything had to run from an internal battery, with hospital-grade ventilation modes, closed-loop gas mixing, capnography and a hospital network connection.
What we did
Partition by hazard, not by convenience
Ten boards: real-time respiratory control with the pressure sensors and DAC outputs, an isolated oxygen and air mixing unit with its own microcontroller, a capnography controller with its own sample pump, battery management, a keypad board and the interface computer.
Replace a bought part that did not fit
The purchased piezo valve driver was too large for the pneumatic block, too slow and designed for mains power. Our driver came in at half the volume and drove the valve 2.5 to 3 times faster, with a supply range for a battery rail under load. A separate two-channel current limiter with a thermostat backstop protects against the roughly 15 microfarad piezo load.
Freeze the safety-critical parts first
The respiratory control board and the gas mixing unit were locked well before the interface, which kept changing while verification ran on everything underneath.
Preclinical testing and handover
Preclinical trials and transfer to production.
Engineering decisions worth copying
- Board boundaries are documentation boundaries. Under IEC 62304 software safety Class C, keeping the interface on its own side of the isolation barrier is the difference between a two-week and a two-month regression cycle.
- Decide make or buy against measured physics. A build decision fails on the bench in month three; a buy decision fails at integration in month eleven, after the mechanics have frozen around the part.
- Name an owner for the power path in week one. On a battery-powered life-support device the power architecture constrains the pneumatics, the compute and the enclosure at once.
- Budget preclinical testing in the original plan. It is part of the program, not the phase after engineering.
Standards that govern verification of a portable ventilator: ISO 80601-2-12, IEC 60601-1-8, IEC 62366-1, ISO 14971 and IEC 62304 (software safety Class C on this program). Full engineering note: Ten boards inside a carry handle: engineering a Class II portable ventilator.
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Sources
Client names are not disclosed. Updated on October 9, 2026.