Exposure to burn pits, sand, diesel exhaust, and chemicals are some of the most commonly cited factors that lead to lung problems for active-duty military. According to the U.S. Department of Veterans Affairs (VA), about 20 percent of patients with severe traumatic brain injury also have acute lung injury, and studies show that there has been an increase in the prevalence of chronic lung disease in veterans of the wars in Iraq and Afghanistan, which translates to deployed military personnel who are at risk of developing acute and chronic lung diseases. These types of respiratory problems lead to serious consequences and VA scientists are seeking new ways to improve the quality of life of their patients.
Researchers at the VA Ann Arbor Healthcare System in Michigan recently announced that they have been working to create a portable artificial lung that could potentially revolutionize the treatment of Veterans affected by lung disease and aid in the removal of CO2 for people with severe lung disease that are often unable to remove enough CO2 from the bloodstream, making even simple daily tasks exhausting. Though still in its infancy, they hope to build biocompatible artificial lungs of very small size for portable or wearable short and long-term respiratory support. As well as develop a novel hollow fiber membrane oxygenator optimized to provide complete CO2 ventilation for patients with acute lung injury or chronic lung disease. The wearable CO2 removal device for Veteran rehabilitation from lung disease is part of a two-year grant project. The VA has been enlisting 3D printing experts at their facilities to develop new medical devices to improve Veterans’ lives, in 2018 they were already working in a different artificial lung using 3D printing and multiple other projects, like 3D printing to prepare for heart surgery using 3D printed models and prosthesis.
3DPrint.com spoke to Alex Thompson, one of the leading biomedical engineers currently working on the design and optimization of artificial lungs, to learn more about the project, which in this first stage involves using 3D printing to built prototypes, which will, later on, be tested using a benchtop blood flow model to confirm the expected performance.
What was the inspiration behind the new artificial lungs in development?
Veterans, in particular, have a higher incidence of lung disease than the general population, so it is a very important problem for the VA in terms of cost and treatment. Unfortunately, there’s no cure for chronic lung disease and the only definitive treatment is to get a lung transplant, which is something many veterans aren’t eligible for, so we are constantly trying to look for new ways to help them. So the project that I’m working on involves designing and developing more efficient artificial lungs than the ones we use in hospitals today. The VA artificial lungs are tailored for adults that have severe lung disease and need to remove CO2 fast from the blood but are unable to. Even mundane everyday tasks can become really exhausting because they can’t breathe fast enough to get rid of the CO2.
We are trying to improve lung technology so that physicians can apply it outside of the Intensive Care Unit (ICU). The oxygenators that we are trying to improve already exist, however, if we make some significant advancements in how well they operate and how biocompatible they are, the success of this technology can lead to artificial lungs as destination therapy, providing an alternative to lung transplant. So the objective is to create smaller, more compact artificial lungs that they could wear around like a backpack and would give some recourse to veterans that are not eligible for a lung transplant.
How is 3D printing helping?
Changing the layout geometry of the artificial lung helps us get better performance. So we have been using 3D printing for prototyping because it is cheaper and faster for us to run a computer simulation for what we consider to be a good design, then we print a couple of models so we can then fabricate and test them before we move forward with more expensive and time-consuming production involving injection molding. So, in this stage, we are using prototyping and the only reason we don’t use 3D printed parts for the final product is because the surface quality of the medical devices that have to be in contact with blood need to be super smooth since any roughness that comes into contact with blood contacts can lead to a clot. Most of our work is printed on a Stratasys J750, while at our lab we use Stereolithography 3D printers to deal with some of the smaller parts.
Do you work directly with physicians?
There are a lot of people with different experience coming together for this project, from surgical fellows to pre-med students looking to get more experience, as well as pioneers in the field, like Robert Bartlett, one of the developers of the artificial lung using extracorporeal membrane oxygenation (ECMO), so we have some great collaborators working on this project. I feel like I wouldn’t have been able to come this far if it wasn’t for the great leadership in both our labs, at the VA Ann Arbor and the University of Michigan’s ECMO lab. We think we are making great progress in the artificial lung, that would be feasible to carry, and safer, more portable and more convenient.
When do you expect patients will be able to use the new artificial lung?
We hope it will be some five to six years before we can begin pre-clinical trials. Our two-year grant allows us to create the initial design, do all of the computer modeling needed, benchtop testing and testing in large animals, which will allow us to basically hook the lung up into a cohort of sheep using the same cannulation technique that we would use in humans. The sheep will be under anesthesia for six hours, during that time we will be able to monitor the animal and the artificial lung to see whether it works, or if we need to go back to the lab. The next step after that will be chronic implantation, which involves the same set up except for the fact that after we hook up the artificial lung, the sheep will be taken out of anesthesia and monitored for 30 days.
This is a very exciting part of the 3D printing network in the VA, which is moving forward quickly using new technologies to develop prototypes, and we are very happy that our Veterans will have a high quality of care, with results that could improve many lives. The device could be used as a temporary measure – a bridge to help patients waiting for lung transplant or an aid for Veterans with recovering lungs. This is one of the many comprehensive 3D efforts across the VA, we expect to have more in the future.