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It is impossible to say that no one saw the pandemic coming. In December 2007, a user of the how-to site Instructables uploaded plans for “The Pandemic Ventilator,” a do-it-yourself machine made from plywood, plastic bags, threaded pipe, and a programmable logic controller (PLC).
“If a pandemic breaks out, hospitals wouldn’t be able to just go out and buy all the ventilators they need, because there wouldn’t be enough parts or production capacity,” warned a user named Panvent, who at the time expected a similar outbreak in birdlife. flu.
Fast forward 13 years and Pandemic Fan seems prescient. America’s national stockpile does not have enough openings to support all the states that need it; many of them in it are broken, and as they search for a cure, the governors rapidly discuss various ideas for alternative ventilators, including hacking anesthesia machines and manual pump-bag valve masks. One hospital in Italy even transformed diving masks into personal oxygen machines for several patients.
In America, states like Arkansas and Florida are still trying to figure out if they have enough machines in preparation for the wave, and President Donald Trump has blamed a number of governors for not being ready. Having an extra fan on hand seems like a good idea. Should you build or hack your own?
A basic machine with lots of bells and whistles
“At its core, a ventilator is a pretty simple machine,” explains Randy Cremer, director of biomedical equipment engineering at the Deborah Heart and Lung Center in New Jersey. “It’s just something that’s going to create a pressure that’s a little bit higher than the pressure in your lungs, so it’s going to make you breathe.”
The creator of the Pandemic Ventilator Project (PVP) seems to agree. Now an engineer at a startup developing a wearable dialysis system, this anonymous biomedical technologist has continued to develop schematics for his pet project, posting them on Blogspot, along with a discussion of the experiments and tangents the project has taken over the past few years.
Many ways to make a fan
If you are interested in making a DIY fan, you might want to check out this Github project page. Includes a spreadsheet that reviews 85 machines for their viability. Leading candidates include the AmboVent, designed by the Israeli Air Force, and the automated bag valve mask, developed by students at Rice University for under $300.
3D printing enthusiasts may want to check out the ArmeeVent project — a 1960s US Army “automatic breathing control” machine that has no moving parts and has recently been reverse engineered. Anyone following the ventilator drama in the early stages of the pandemic likely saw headlines that hundreds to thousands of machines in the nation’s stockpile were broken. Why? Fans are often pneumatic machines with valves, solenoids and diaphragms, Cremer explains. These parts can dry out and become brittle and need to be replaced. The built-in electronics can fail. A vent with no moving parts can theoretically solve some of the problems that come with age.
However, if you need to increase production in the short term, which is an immediate need, printing or building a fan from scratch is probably not the way to go. Most of these machines must be approved by the Food and Drug Administration, and using one that hasn’t been tested for safety can have serious consequences.
The danger of DIY
“I’m really leery of this do-it-yourself stuff,” Cremer says. “The problem with building such a simple machine is when something goes wrong. If that machine continues to put pressure on a patient who can’t handle it, you can cause further damage.” Even the best oxygen machine needs a medical team to dial in the right numbers for the patient’s lung capacity. An advanced ventilator used in the ICU will often have an alarm that will alert a nearby nurse or physician when the patient is struggling with airflow.
Although some of the proposed DIY projects have similar sensors, there are also legal issues.
“As a manager, I also deal with regulatory issues,” explains Cremer. “There’s the whole issue of FDA and patient safety.” Even the best DIY ventilator would probably need FDA approval to be used in a hospital.
Szymon Chrupczalski explains the functionality of the VentilAid respirator, which can be made cheaply with 3D printed and widely available parts. Plans are available on the web. (Photo by Artur Widak/NurPhoto via Getty Images) NurPhoto/Getty
To simplify things, some strategists suggest hacking anesthesia machines, which are already in hospitals and have built-in ventilators in case they are needed during surgery. Most will require only minor adjustments.
That approach, however, also enters dangerous territory. Cremer says the manufacturer of the anesthesia machines used at the Deborah Heart and Lung Center has already issued a statement warning that the use of any of the medical devices converted to full-time ventilators would be considered “off-label” and the hospital would be responsible for all the patients’ problems.
Anesthesia machine respirators are not designed to be used for the weeks or months that a COVID-19 patient often needs, Cremer says. “They are only meant to be used for hours or for surgery.”
An FDA-approved hack?
A team of California doctors and engineers from the University of California, Berkeley, and the University of California, San Francisco, have a hack that the FDA has already said won’t need emergency approval. Concerned about the lack of ventilators, engineer Bryan Martel wondered if a CPAP machine could be modified to help patients with COVID-19. Martel suffers from sleep apnea and has one of the breathing machines at home. He quickly expanded the concept to include BIPAP machines, which are also used to treat sleep apnea and deliver pressurized airflow.
“There are already millions of these devices,” explains Dr. Ajay Dharia, one of Martel’s partners on the Ventilator SOS project. “If we can find a way to repurpose them, we’re well on our way to bringing them into clinical use. The machines are already made, so you don’t have to manufacture anything.”
Dharia says ventilators should still be the top priority, but team CPAP and BIPAP machines can potentially be used to support patients who still need pressurized oxygen and don’t urgently need a more advanced device.
While Dharia spends much of his time as a principal at Med Tech Venture Partners, which focuses on early-stage medical device funding, he still sees patients (at Kaiser Permanente and Sutter hospitals) and is concerned about how quickly lung capacity in the COVID- and reduces. 19 patients can refuse.
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“We see that people come – even young people – and when they come they have minimal support. For 24 hours, they are on maximum support, so they break down incredibly quickly,” says Dharia. On the positive side, many patients’ lungs do not become too stiff and respond well to air pressure.
“With more flexible lungs, you can get through with a little less pressure,” says Dharia. “This actually works to the advantage of BIPAP and CPAP machines, which can deliver extremely high pressures.”
The Ventilator SOS team adapts these machines by adding an endotracheal tube attachment, using parts readily available in most hospitals. They also modified the machines to deliver large amounts of oxygen, which may be necessary in some patients.
In addition to publicizing the plans to modify CPAP/BIPAP for anyone who can use, the team is also asking people who have one of these machines that they are not using to donate them to be remodeled and distributed to hospitals in need.
Cremer agrees that using CPAP and BIPAP machines makes more sense than many DIY options. He also sees a way to use some DIY knowledge: 3D printing parts for old fans. He says there is a stockpile of extraordinary breathing apparatus that can be brought back to life with a newly printed valve or other part.
“That’s what the 3D printing community should be focusing on — printing the parts for these things,” Cremer says. “Instead of coming up with new projects, it’s safer.”
As for DIY projects, his bar for using them remains high: “At the end of the day, if it’s something like a zombie apocalypse – yes – but I don’t think we’re there yet.”
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Source: newstars.edu.vn