A team of engineers and physicians at the University of California San Diego has developed a low-cost, easy-to-use emergency ventilator for COVID-19 patients that is built around a ventilator bag usually found in ambulances.

The team built an automated system around the bag and brought down the cost of an emergency ventilator to just $500 per unit. The device’s components can be rapidly fabricated  and the ventilator can be assembled in just 15 minutes. The device’s electronics and sensors rely on a robust supply chain from fields not related to healthcare that are unlikely to be affected by shortages. 

The UCSD MADVent Mark V is also the only device offering pressure-controlled ventilation equipped with alarms that can be adjusted to signal that pressure is too low or too high. This is especially important because excessive pressure can cause lung injury in COVID-19 patients that often experience rapid decreases in lung capacity as the disease progresses.  

Most ventilators measure the volume of air that is being pumped into the patient’s lungs, which requires expensive airflow sensors. By contrast, the UCSD MADVent Mark V measures pressure and uses that data to deduct and control the airflow to the lungs. This was key to lowering the device’s price. 

The team from tUC San Diego and industry partners will be seeking approval for the device from the Food and Drug Administration. They detail their work in an upcoming issue of Medical Devices and Sensors. 

The device’s plans and specifications are available at http://MADVent.ucsd.edu/

“The MADVent can safely meet the diverse requirements of COVID-19 patients because it can adjust over the broad ranges of respiration parameters needed to treat acute respiratory distress syndrome,” said James Friend, a professor at the UC San Diego Jacobs School of Engineering and one of the paper’s two corresponding authors. “The combination of off-the-shelf components and readily machined parts with mechanically driven pressure control makes our design both low cost and rapidly manufacturable.” 

 Researchers also wanted to make sure that the device could be used by healthcare workers with limited experience with ventilators and no experience with this type of system, said Dr. Casper Petersen, co-author of the study and a project scientist in the Department of Anesthesiology at the UC San Diego School of Medicine. As a result, the MADVent Mark V is safe to use, easy to assemble and easy to repair.

“This device could be a great option for use in situations where materials are scarce, such as when  the normal supply chain breaks down, or in developing nations and hard-to-reach rural areas,” Dr. Casper Petersen said. 

The device is not meant as a substitute for the highly complex ventilators used in Intensive Care Units.

“Rather, our low-cost ventilator is meant to bridge an urgent gap in situations of a large surge in patients where we may not have enough life sustaining equipment”, said Dr. Lonnie Petersen, an assistant professor at the Jacobs School of Engineering, adjunct professor at UC San Diego Health and the paper’s other corresponding author. “Safety is our main priority; while the MADVent is a low-tech and low-cost device, it actually offers robust and patient tailored ventilationThis really increases the safety for the patients suffering from the complex pulmonary infection and respiratory distress associated with COVID-19”. 

The UCSD MADVent Mark V

The UC San Diego team built their device around a ventilator bag usually found in ambulances and designed to be manually squeezed to help patients breathe. In the UCSD MADvent Mark V, a machined paddle squeezes the bag instead. The paddle is controlled by a series of pressure sensors to make sure the patients get the appropriate flow of air into their lungs. The team deliberately integrated as many standard hospital items as possible into the design because those have already undergone rigorous testing for safety, longevity and compatibility. 

To measure pressure, the researchers developed an algorithm that deduces how much the bag was compressed based on how many turns the device’s motor has made and calculates the volume of air sent into the patient’s lungs as a result.

“The elasticity of the lungs changes very quickly, so it’s important to be able to sense the feedback from the patient,” said Dr. Lonnie Petersen.

Researchers tested their system more than 200 times and for days on end on a lung simulator, adhering to standards for the International Standards Organization and FDA guidelines to ensure it functioned correctly. The device was also tested on a medical mannequin simulator.

One of the keys for cost savings was developing computer models of the volume of air delivered through the ambulance bag when it is compressed. This allowed researchers to do away with expensive airflow sensors and the complex algorithms that control them.

The materials on the ventilator can be sanitized with conventional disinfectants such as 1.5% hydrogen peroxide and 70% ethanol.  

“The system, in its current state of development, can easily accommodate new modules that enable more sophisticated features, such as flow monitoring, which can enable additional ventilation modes and provide healthcare operators more information regarding a patient’s breathing,” said Aditya Vasan, a Ph.D. student in Friend’s research group and the paper’s first author. 

Collaboration across disciplines

A close collaboration between clinicians and engineers enabled the team to put together a crude prototype in just three days. They then spent countless hours refining and testing the ventilator.  A lot of work went into making sure it was safe and could be manufactured with simple parts at a large scale.

Engineers with the UC San Diego Qualcomm Institute Prototyping Lab provided engineering design and fabrication support.  Electrical engineer Mark Stambaugh stepped in to work on the microcontroller and help adjust the stroke cycle and control the speed and volume of the compressions to help patients breathe. Mechanical engineer Alex Grant provided design support and guidance.

Seed funding for the project came from several organizations: San Diego-based Kratos Defense & Security Solutions, Inc., which develops fields systems, platforms and products for national security and communications needs; the US Office of Naval Research in the Department of Defense; and the Catalyst initiative at the UC Institute for Global Conflict and Cooperation.

MADVent: A low-cost ventilator for patients with COVID-19

Corresponding authors: James Friend, Dr. Lonnie Petersen

UC San Diego Jacobs School of Engineering: Medically Advanced Devices Laboratory: James Friend, Aditya Vasan, Reiley Weekes, William, Connacher.

UC San Diego School of Medicine: Dr. Casper Petersen, Dr. Sidney Merritt, Dr. Preetham Suresh, Dr. Daniel E. Lee, Dr. William Mazzei, Theodore Vallejos, Jeremy Sieker. 

Qualcomm Institute: Mark Stambaugh, Alex Grant.

Eric Schlaepfer, independent researcher

View original article here.

Engineers at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, California, have come up with a design for a high-pressure ventilator that can mechanically breathe for patients with the most severe cases of COVID-19 (coronavirus)—and they did it in just 37 days.

“We specialize in spacecraft, not medical device manufacturing. But excellent engineering, rigorous testing and rapid prototyping are some of our specialties,” JPL Director Michael Watkins said in a prepared statement. “When people at JPL realized they might have what it takes to support the medical community and the broader community, they felt it was their duty to share their ingenuity, expertise and drive.”

The lab joins various other ventilator-making efforts, as the U.S. faces a shortage on the order of 300,000 to 700,000 units. Tesla has retrofitted some of its Model 3 car parts to build the life-saving breathing machines, while Ford and General Motors have restructured assembly lines for ventilator manufacturing. Dyson pivoted from vacuums to ventilators in just 10 days, and even CERN, home to the Large Hadron Collider, has shifted from particle physics to ventilators.

Although all of these firms design and engineer technical devices, none of them are specialized to the effort. Not only do ventilators contain sophisticated hardware—from pressure generators, to patient circuits, to filters, and valves—but the software is also sensitive. If even one component is faulty, the entire machine shuts down.

NASA submitted its prototype to a renowned medical facility in New York City, where the virus is raging, for feedback. At Mount Sinai Hospital, researchers at the Human Simulation Lab in the Department of Anesthesiology, Perioperative, and Pain Medicine conducted further testing.

“The NASA prototype performed as expected under a wide variety of simulated patient conditions,” Matthew Levin, M.D., director of innovation for the Human Simulation Lab, said in the statement. “The team feels confident that the VITAL ventilator will be able to safely ventilate patients suffering from COVID-19 both here in the United States and throughout the world.”

Because its made of fewer parts, NASA says that VITAL can be built faster, and be maintained more easily, than traditional ventilators. Since the design is relatively flexible, health care workers can even modify VITAL for use in makeshift hospitals popping up in convention centers and hotels across the U.S. as brick-and-mortar hospitals reach max capacity.

VITAL machines aren’t meant to permanently replace expensive hospital ventilators. Those are meant to last for years and have various modes to meet a range of medical issues. Rather, the NASA ventilator is specifically meant to treat COVID-19 patients and has an expected lifespan of about three or four months.

“Intensive care units are seeing COVID-19 patients who require highly dynamic ventilators,” J.D. Polk, M.D., chief health and medical officer for NASA, said in the statement. “The intention with VITAL is to decrease the likelihood patients will get to that advanced stage of the disease and require more advanced ventilator assistance.”

Currently, NASA is seeking emergency use authorization from the U.S. Food and Drug Administration. That process ensures the government agency can approve critical medical devices in days, rather than years. Once complete, Caltech’s tech transfer office, which manages JPL, will offer a free license for VITAL.

The university is currently looking for manufacturing partners to bring the design to life.

A team of researchers from the Royal Women’s Hospital, Monash University and the Alfred Hospital has successfully tested, in a simulated environment, the potential to ventilate two lungs of different compliances from a single ventilator using only commonly available hospital equipment. While the authors do not condone the practice of ventilator splitting and say the findings must be interpreted and applied with caution, the experiments demonstrate the hope of simultaneously ventilating two test lungs of different compliances and modify the pressure, flow and volume of air in each lung, in case of extreme emergencies.

“Patients with COVID-19 may develop progressive viral pneumonitis leading to severe respiratory failure,” said lead author Dr. Alexander Clarke, a researcher in the Department of Anaesthesia at the Royal Women’s Hospital.

“The combination of unprecedented disease burden and global supply chain disruption has resulted in worldwide shortages of medical equipment.”

“Despite our advances in the practical application of ventilator splitting, the practice is unregulated and under tested. But as the COVID-19 pandemic continues to grow, some countries, like the USA, may consider ventilator splitting on compassionate grounds. The U.S. FDA has passed emergency use authorization for the splitting of ventilators.”

“While ventilator splitting has, at face value, validity in addressing ventilator shortages, we agree that on sober reflection, it is a solution that needs to be weighed up carefully as it may cause more harm than good.”

The basic principle of ventilator splitting is simple — two or more patients are connected to one ventilator and both are exposed to the same circuit dynamics.

This presents many challenges including ventilator and patient synchronicity — ventilation requirements are different for a 100 kg male and a 50 kg female, cross-infection from inter-patient gas exchange, oxygen concentration, and the lack of monitoring for individual tidal volume, flow and pressure. Irregularly pressurized air supply can kill patients.

To counter this, Dr. Clarke and colleagues connected a flow restrictor apparatus, which consisted of a Hoffman clamp and tracheal tube, to the inspiratory limb of the ventilator to the high compliance test lungs.

The breathing circuit ran from the humidifier to a hospital-commodity Y-connector splitter.

From the splitter, two identical limbs were created, simulating the ventilation of two pairs of patient lungs.

The resistance was modified to achieve end-tidal volumes of 500 ml ± 20 ml.

“The addition of the flow restrictor was critical to the way this setup works — without the restrictor, we weren’t able to control air flow to each simulated patient,” said co-author Dr. Shaun Gregory, a scientist in the Department of Mechanical and Aerospace Engineering at Monash University.

While the findings are exciting for crisis and trauma medicine, they need to be interpreted and applied with caution.

“Our experiment has demonstrated that in order to deliver a safe tidal volume and airway pressure, a resistance mechanism is required on at least one inspiratory limb of the circuit,” Dr. Gregory said.

“One way of achieving this is through the use of a tracheal tube and Hoffman clamp — common, practical items found in hospitals.”

“While the discovery is promising, the use of this method in the clinical context has not been validated and we don’t recommend its wider use without further trials.”

“We are hopeful of one day being able to get great surety with this approach to ventilator splitting so we can help save lives in dire cases of emergency.”

The team’s paper was published in the journal Anaesthesia.

View SciNews Article HERE.

HOUGHTON — As COVID-19 cases have surged, the shortage of working ventilators has become one of the biggest obstacles in treating patients.

A Michigan Technological University professor is one of the people working on a solution. Joshua Pearce, Richard Witte Endowed Professor of Materials Science and Engineering and a professor of electrical and computer engineering, is co-editor in chief of HardwareX, an open-source scientific hardware journal. It is now accepting submissions for an issue with proposals for making ventilators and other necessary equipment, such as non-contact thermometers and N95 respirators. Those can be through 3-D printing, or with materials and tools readily available at hardware stores. 

Several previous authors have indicated they will submit papers, Pearce said. One South American researcher is testing an open-source ultraviolet sterilization method that can be used for entire rooms. 

“He had done it for biological research, but he’s adapted it for a hospital setting as well,” Pearce said. 

Submissions will be taken until June 1, then posted online within a week of their acceptance. HardwareX is making the issue available to all to ensure a fast peer review. 

Michigan Tech is also tackling the problem. Pearce runs the Michigan Tech Open Sustainability Technology (MOST) Lab. He is also part of Tech’s Open Source Initiative. 

One approach they are working on is recreating a low-cost ventilator used by a Tech Enterprise team that was deployed in Africa. 

“That is slightly challenging because we only have access to one of the labs on campus,” Pearce said. 

Testing is using artificial lungs from Michigan Instruments to simulate the ventilators’ effect on humans. 

“No one is quite there yet,” Pearce said. “It’s very, very challenging on the software side to control the pressures so you don’t damage people’s lungs.”

COVID-19 closures have already caused problems with access to some places. One of the most promising leads was a paper published in 2019 by a research team in Pakistan, with whom Pearce had been working. The team had access to an artificial lung and could run tests immediately. However, their university was shut down due to the pandemic. 

“The last version of the code is stuck on some computer at the university, and nobody can get access to it,” Pearce said. 

Other researchers are looking at converting a CPAP machine to assist people in breathing. 

All of this is taking place when teams are restricted to what Pearce calls “the absolute worst way to do designing”: limits on how many can be in a lab, limited access to equipment and disrupted supply chains. Before the next pandemic, Pearce said, there should be government-funded open-source designs pre-tested and ready to put into place when the need arises.

“That would relieve a lot of the costs associated with having stockpiles, and really help the countries that don’t have the capital to build 10,000 ventilators,” he said. 

In March, Pearce conducted a review of open-source ventilators. While promising, he said, the systems that had been tested and peer-reviewed did not have full documentation. Those that were documented were either early designs or had not finished testing. 

“With the considerably larger motivation of an ongoing pandemic, it is assumed these projects will garner greater attention and resources to make significant progress to reach a functional and easily replicated open source ventilator system,” he said. 

A $1,500 ventilator system being developed by the Innovative Global Solutions Enterprise team at Tech had been one of the furthest along, Pearce said. However, it could not reach its fundraising goal through Superior Ideas, Michigan Tech’s crowdfunding platform. 

“If it had been funded, we’d probably have the solution already and we could shop it out,” Pearce said.

See The Daily Mining Gazette Article HERE.