Pittsburgh CNC Vent

A rapidly scaleable emergency ventilator for Covid-19

Why Design a Ventilator

The rapid advance of Covid-19 has the potential to overwhelm our health care system. Several areas of need have been identified including personal protective equipment (PPE), Corona virus specific testing kits, hospital beds and ventilators. Ventilators have been identified as a key resource to treat the respiratory illness that is associated with Covid-19. However, ventilators are in limited supply and their complexity of construction and supply chain make it difficult to rapidly produce new units. Our team has been working on an ultra-low cost, easy to manufacture ventilator that can rapidly achieve scale.

Engineered for Manufacturing

Our design philosophy is based on the simple premise: "If you needed to produce 1M ventilators in 2 months, how would you do it?" Those volumes, in that timeframe, requires manufacturing methods to be a critical input to the design. The result were the following criteria:  

  1. No or minimal electronics - motors, pumps, sensors and other electronics can be used to develop a prototype, but those same components are only available in relatively (low thousands) small quantities. Larger quantities must be ordered (likely from China) which could take months to receive.

  2. Distributed US-based manufacturing - travel restrictions and factory closures worldwide have strained supply chains and made them unreliable. However, there are tens of thousands of machine shops and manufacturing sites in the US capable of producing components and final assembly if parts are designed to leverage their available CNC machines.

  3. Alternate manufacturing methods - provide multiple configurations when possible so that manufacturers with different machines (i.e. mill vs lathe) can produce a version.  

  4. Leverage approved FDA-devices / approaches - with little or no time to perform a typical clinical trial, this device must leverage prior devices and their test results. Even with the FDA's Emergency Authorization Act a device that can point to a predicate device has a greater chance of approval and use in the field.

Approach

We have prototyped an emergency-grade ventilator that runs strictly on compressed air which is readily avaiable within a hospital. This design was inspired by design elements from FDA-approved devices. It can be produced in a matter of minutes at machine shops using standard manual or automated CNC machines.  Below is a video of operation. Adjustment dials enable the max lung pressure (PIP) and respiration rate to be adjusted. The PIP / PEEP ratio can be modified by replacing a single component. This unit uses standard hospital fittings making it easy to add a pre-heater, humidifier and filter.  This is not intended to replace a full featured vent, but simply to be an alternative if no other vent is available.

Above: operation of prototype unit cycling ; Right: comparison of prototype vs. FDA approved device based on similar principles.

Status

This project was always viewed as an insurance policy. The 'best' approach to ventilators would be use the full featured vents that are preferred by hospitals. As the spread has slowed and ventilator capacity is increasing it does not appear that there exists the need for this device. That is a good thing! For now, we pausing efforts on this project but can rapidly ramp it back up if needed.  

We've been asked if this could be leveraged in countries where