There are a wide variety of projects related to 3D printing ventilator parts in response to the COVID-19 outbreak. In some cases, these are the most terrifying attempts to address supply shortages from a health perspective because, if they are deployed and don’t work properly, they can both spread the SARS-CoV-2 virus further and hurt patients.
To understand these dangers, we are juxtaposing what really seems to be a functional and safe method for increasing ventilator supplies with some other solutions that are more questionable in terms of safety and functionality. The 3D Design and Innovation division at Northwell Health , New York State’s largest health care provider and private employer, developed a method for adapting common BiPAP (bi-level positive airway pressure) machines into functional invasive mechanical ventilators.
Northwell’s analytics department had been tracking the spread of the pandemic and the number of ventilators within its healthcare system. This led the healthcare provider to the conclusion that, with the virus spreading at its projected rate, it wouldn’t have enough ventilators to meet the anticipated patient surge. To prepare, a team led by Hugh Cassiere, MD , medical director for respiratory therapy services at North Shore University Hospital (NSUH) and Stanley John, NSUH’s director of respiratory therapy, worked with Todd Goldstein, PhD, director of 3D Design and Innovation at Northwell Health to develop an alternative solution.
Northwell Health wanted to prepare and make sure it had as many ventilators, and options, available to prep for a surge of patients. Across the health system, 350 BiPAP machines were sitting idly. BiPAP systems are similar to the CPAP machines consumers are more familiar with for the treatment of sleep apnea. However, while CPAPs provide continuous pressure to keep a sleeper’s airways open for inhalation, BiPAPs can produce breaths and maintain air flow, which is similar to how ventilators operate. While both BiPAPs and CPAPs are non-invasive devices that rely on masks, ventilators are invasive and involve the placement of an endotracheal (ET) tube down the throat of a patient that cannot breathe on their own.
The Northwell team then worked on a method for converting their BiPAP systems to work as ventilators. This meant forgoing the traditional mask, which not only has the potential for allowing the SARS-CoV-2 virus to leak from the patient to infect the room but also cannot be used on intubated patients. The Northwell doctors developed a 3D printable adapter that connects an ET tube directly to a BiPAP, as well as an exhalation port that can be connected to a HEP filter to prevent COVID-infected air from passing into the surrounding environment. The video below was provided by Northwell Health.
Ventilators may be in short supply globally to the point that manufacturers are not just kicking up production but opening up their designs for others to make. In contrast, ET tubes are disposable parts that have already been made in abundance and BiPAP machines are likely the best stand-in option for ventilator units. While the adapter was printed using Form 2 systems within a Formcell mass production system at Northwell and used on a Philips Respironics V60 BiPAP machine, other printers can produce the part for other BiPAPs, as long as the machine’s software can be used similarly to traditional ventilator units.
The BiPAP machines don’t have the same bells and whistles as ventilators. However, these are hospital-grade systems that, according to Dr. Goldstein, function appropriately for COVID patients.
“You do have more control with a normal ventilator and by no means are they going to start replacing ventilators with converted BiPAP machines. However, in a pinch, which we were in, we converted all the BiPAPs we had. The software is compatible, and the pumps are strong enough and able to do what we need them to do without a problem,” Goldstein said. “A layman who might walk into the hospital wouldn’t even know the difference.”
Due to Northwell’s foresight and the ingenuity of the team that developed the BiPAP adapter strategy, the Northwell system did not run into the supply shortages it had anticipated.
“As it stands right now, things have looked better, but one issue we were able to account for is that we didn’t ever have a shortage of ventilators. By converting BiPAP machines, we were able to get enough to cover the surge,” Dr. Goldstein told 3DPrint.com.
Clarifying Other Vent Projects
There are a number of other projects being publicized whose exact application may be difficult to distinguish from others. Here, we’ll try to clarify what these various devices are and their potential level of safety. Before we get into each project, it’s important to note that “ventilator” and “respirator” are often used interchangeably, which can be even more confusing due to the fact that N95 masks, with built-in filters, are also sometimes referred to as “respirators.”
Isinnova’s Charlotte Valve: The “Charlotte valve ” from Italy’s Isinnova is a 3D-printed adapter that converts a Decathlon snorkel mask into a CPAP mask for sub-intensive therapy by connecting to CPAP machines or wall oxygen. This was meant to address shortages of CPAP masks at an Italian hospital. As long as there isn’t a shortage of scuba masks, it may be a safe and sufficient solution for CPAP replacement but is not a solution for ventilator supply issues.
Mateiralise’s PEEP Mask: Materialise has developed a positive end expiratory pressure (PEEP) mask for emergency breathing assistance so that true ventilators can be reserved for critical patients. Whereas this mask operates along similar principles as the Isinnova device, providing positive pressure and a flow of oxygen, it is currently being fast-tracked through the regulatory process and, therefore, suggests a greater degree of safety and viability. This device could potentially replace ventilators in some cases as a treatment.
Venturi Masks and Valves: The story that may have been the first to draw in the entire 3D printing community into the supply effort was that of Isinnova and its reverse-engineered venturi valves, which are an important component in non-invasive oxygen therapy using venturi masks . Like the aforementioned masks and unlike ventilators, venturi masks do not use ET tubes. Isinnova and Lonati SpA in Italy were able to replicate traditionally made valves for these masks with 3D printing and began batch printing them using an SLS ProX 610 printer.
PPE Masks: None of these masks should be confused for items like the Pneumask, which converts a snorkel into a N95-style masks used as personal protection equipment.
Vent Splitters: A wide array of ventilator splitters are currently being printed from smaller organizations such as 3D Hubs all the way up to pharma giants like Johnson & Johnson. These devices are meant to divert oxygen from a single ventilator into ET tubes for multiple patients. Such a device has some validation in the way of operation on lung simulators for non-printed splitters . Prisma Health and Ethicon Inc., a Johnson & Johnson company, have received Emergency Use Authorization (EUA) from the U.S. Food and Drug Administration (FDA) to 3D print its VESper Ventilator Expansion Splitter .
According to Dr. Goldstein, splitting ventilation can increase the number of issues that may be encountered by medical professionals and their patients. Every patient requires a different amount of oxygen flow depending on their personal lung capacity. Such devices may be a very last resort measure for addressing ventilator shortages but are far below converting BiPAP equipment in terms of backup strategies.
Emergency Ventilators: There are a number of initiatives in process attempting to develop ventilator devices, ranging from dangerous to potentially viable. On the viable end of the spectrum is the Leitat1, an emergency resuscitation device that forces air into a patient’s lungs via mechanical pump and is undergoing emergency approval by the Spanish government.
This device is for short-term emergency use, based off of a tool that EMTs might use to resuscitate someone in the field. These respirators have a high incidence of delivering too much air to the patient which could lead to them aspirating vomit into their airways or lungs and dying. Still, the Leitat1 is going through official channels, while numerous other devices are being developed by non-medical professionals that could be even more potentially dangerous.
From what we can understand about these various devices, a method for simply converting available BiPAP machines into ventilators would be the safest and straightforward for addressing the ventilator shortage when possible. There may scenarios where even that is not an option, however, and so other techniques could be required.
Approved by the FDA for emergency use, the Northwell BiPAP adapter relies on existing FDA-approved, tried-and-trusted medical equipment. The hospital system has received requests from the Veterans Affairs department of the federal government all the way down to Northwell’s own competitors. The design is freely available to medical professionals who can visit the Northwell Health website to request the file and instructions for using the device.