When it comes to evaluating ventilator performance, a lung simulator is an invaluable resource. The testing of a ventilator should take place before it’s ever used on patients in a clinical environment. Periodic testing is also needed to ensure that the unit is performing in accordance with established standards as well as the manufacturer’s specifications.

Based on the standards set forth by the American National Standards Institute (ANSI), the International Organization of Standardization (ISO), and the American Society for Testing and Materials (ASTM), the Michigan Instruments Test Lung Simulators are an ideal testing option. Our devices meet or exceed ventilator performance standard requirements.

Standards References: ANSI Z79.7, ISO 80601-2-12, ISO 80601-2-13, ASTM F 1100-90

So what exactly are the TTL or Training & Test Lungs as we call them? They are one-of-a-kind lung simulation devices that use elastomer lung compartments to accurately reflect lung capacity in typical infants and adults. They simulate the mechanics of the human pulmonary system from the upper airway through the lungs in a realistic and repeatable way. You can easily alter lung compliance and airway resistance to simulate a variety of healthy and diseased lung conditions.

What to Expect From Our Lung Simulators

Lung simulators by Michigan Instruments feature built-in volume scales and pressure gauges to offer real-time feedback. They contain a number of ports to make monitoring, sampling, or introducing gas or agents easy during the testing process. To view, record, and replay data, you can add our PneuView electronics and software.

Our lung simulators are designed to meet a variety of needs. We offer adult and infant versions in single-lung and dual-long models. Time after time, manufacturers depend on them for versatility, durability, and most importantly, accuracy.

In addition to routine testing, lung simulators can be used to troubleshoot equipment problems or simulate unusual scenarios. They also make it convenient to quickly train staff on new respiratory devices and procedures. The dual lung TTL units can be used to simulate spontaneously breathing patients, which makes it a useful tool for evaluation and training on  supportive and non-invasive technologies. Additional information about applications and instructional videos are available online.

Coronavirus and Lung Simulators

As many ventilator manufacturers ramp up production and other manufacturers begin to produce ventilators, our test lung simulators can be particularly beneficial for testing these devices. There are studies in progress that show in patients with the most severe cases of COVID-19, a ventilator may allow for the best chance of survival. Our lung simulators can ensure that new and existing ventilators and ventilation equipment are tested and ready for use on patients.

Contact Michigan Instruments Today

If you’re new to manufacturing ventilators and are looking for testing or calibration assistance, we’re happy to answer your questions and provide a quote. We have experienced an increased demand for our products and have ramped up our own production to serve manufacturers and service providers across the country and the world. Contact us today.

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. View original article from Popular Mechanics here.

“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.

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.