Doctoral student Kaitlyn Elmer, left, works with associate professor Morten Jensen in his lab.
Simple, Beautiful but Complex: Biomedical Researcher Morten Jensen’s Take on the Human Heart
By Hardin Young
One percent of all babies has some type of heart defect, said Morten Jensen, an associate professor of biomedical engineering who specializes in developing innovative medical devices and experimental cardiovascular surgery.
“That’s nothing to be alarmed about because you don’t see one out of every 100 live births needing surgery,” he said. “The majority of people who have small defects never need to worry about it.”
A case in point: Jensen himself has a leaking pulmonary valve, discovered by a colleague who assured him that 60% of adults suffer from the same condition. Which invites the question: if more than half of all adults has a leaky valve, is it even a defect?
“Many things can go wrong in the development process of the heart, and it’s one of the imperfect wonders of nature that creates something that is so remarkable,” he said. “It’s a design that took 5 billion years to develop.”
Jensen’s fascination with the heart stems from a deep understanding of its function and mechanics, which he sums up as “simple, beautiful but incredibly complex.”
Jensen came to the University of Arkansas in 2015 as an Arkansas Research Alliance Scholar and is now the principal investigator at the Cardiovascular Biomechanics Laboratory. Unfortunately, he has his work cut out for him: cardiovascular disease is the number one killer worldwide while Arkansas and its surrounding states have the highest death rates from cardiovascular disease in the United States (the others are nearby Oklahoma, Mississippi, Louisiana and Alabama).
The CBLab brings engineers and clinicians together to address conditions such as heart attack, stroke, heart failure and congenital heart disease while creating novel approaches in the prevention, diagnosis and treatment of cardiovascular disease.
One prototype of a device to monitor bleeding that Jensen is working on with a multidisciplinary team.
A Transformative Internship
Jensen got into the field almost by accident. When he was a computer and electrical engineering student in Denmark, where he was born, he was required to do a one-semester internship on a research or industry-related project. He did this with the Bioengineering Department of Aarhus University Hospital, where he witnessed heart surgeries on humans, including a heart transplant. The experience set him on an entirely new course.
“I thought it was extremely fascinating with the heart being a pump,” Jensen explained. “You could look at the heart as a mechanical device, adding pressure to fluids and the fluids flowing into the blood vessels.”
He also witnessed researchers doing experiments on large animals.
“I saw what the researchers were able to do on large animals in the basement of that hospital — making measurements on the hearts, both electrical and force measurements, flow measurements and pressure measurements. And that’s why I became interested in this work.”
One of the people working in the basement was J. Michael Hasenkam, who was part of the team that invented Transcatheter Aortic Valve Implantation, or TAVI, a revolutionary procedure that enables surgeons to implant a new heart valve with a catheter by going through a blood vessel in the armpit or groin. Ten years later, after Jensen had earned a master’s degree in biomedical engineering at the Georgia Institute of Technology, Hasenkam would become one of Jensen’s Ph.D. advisers back at Aarhus.
In 2015, Jensen became just the third engineer in Denmark since 1479 to obtain the prestigious Doctor of Medical Science degree, which ranks above a Ph.D.
A stent in gel attached to a pressure hose.
The Angle of Bifurcation
Since he saw that first heart transplant, Jensen has helped contribute intellectual property to nine patent applications. This has included development of lifelike artificial tissues to aid medical students in their training, spoons to assist with the removal of bladder stones on companion animals and a heart valve created from animal tissues that can be implanted in humans.
Kaitlyn Elmer, a Ph.D. student in biomedical engineering from Springfield, Missouri, conducts research in Jensen’s lab. Elmer and Jensen are specifically focused on arterial blockages at a coronary bifurcation. This is where a major artery splits into smaller blood vessels. Elmer noted that “20% of plaque blockages are actually in a bifurcation. And since it’s branching, it’s just a weird shape and really difficult for physicians to use conventional methods to treat those.”
Normal methods employ a balloon to expand a stent that props the vessel open, she said. These constructs are usually cylindrically shaped, but the bifurcation typically is not.
She and Jensen are working with cardiologists to create a stent that is designed to fit in the bifurcation, which can have a range of angles. This has required development of a computer program to measure the angles of these bifurcations, so that they can design better balloons and stents. Prototypes are then created and tested in ballistic gel models to see how the stent’s shape changes when expanded.
The project is funded by the American Heart Association, and the technology is promising enough that they applied for two patents through the U of A’s Technology Ventures: one for the software program that measures the angle of bifurcation and another for the devices.
Vascugenix, a company based in Little Rock specializing in medical devices for interventional cardiology surgery, has signed an option agreement with Tech Ventures that would pave the way for licensing pending further development.
Noah Ascher, CEO of Vascugenix, said, “There is a clear need for a solution in the treatment of bifurcation lesions, and it is our company’s vision to work with Dr. Jensen to develop, manufacture and deliver a comprehensive stent system for addressing this need.”
Doctoral student Kaitlyn Elmer.
A Better Way to Detect Internal Bleeding
Jensen is also the principal investigator on a recent $1.9 million award from the U.S. Department of Defense to develop a wearable device for the early detection and monitoring of internal or external bleeding.
Hemorrhagic shock is currently the leading cause of preventable death in casualty care settings. Existing methods often fail to detect blood loss until the onset of shock, which can be too late for some patients. This makes early detection and management of bleeding-related conditions critical to improving survival rates.
Jensen is working with a multi-disciplinary team to design a mobile device that can detect blood pressure waveforms, which correlate with the volume of blood within the blood vessels, the “intravascular volume,” and can be used to determine if blood volume is falling due to hemorrhaging. This will enable first responders and hospital staff to get more accurate readings earlier and respond with better timed and more precisely calibrated care.
Jensen will be joined by Jingxian Wu, a U of A professor of electrical engineering, and Robert Saunders, associate department head of electrical engineering and computer science. Hanna Jensen, an assistant professor in the Department of Surgery at the University of Arkansas for Medical Sciences and course director of the school’s cardiovascular module, will oversee the translational and clinical phases of the project.
Ultimately, their goal is to develop a device that is less than an inch square and sells for less than $100. It would have a catheter that connects to a vein as well as a port to which an IV bag could be connected.
Robert Saunders, an associate department head of electrical engineering and computer science, is part of Jensen’s multidisciplinary team working on a device to detect bleeding.
Collaboration Is Key
Saunders, who teaches a senior design class in the College of Engineering, has worked with Jensen on a range of projects. How many? “Wow, that’s a long list,” Saunders said, before rattling off a few: “Heated pulse oximeters for people who have bad circulation. Wheelchair monitors for disabled people. An Ohm device to determine whether an artificial knee has appropriate motion.”
Saunders said of Jensen, “He’s a great part of the team. Everybody is really dedicated to the project they’re working on. They’re dedicated to the students around them.”
Collaboration is clearly key to Jensen’s success, from witnessing those teams in the Aarhus basement, to all the adjoining names on his patent applications, to his recent research projects.
In fact, one of his closest collaborators is his wife, Hanna, who is an M.D. She said she knew Jensen professionally before knowing him personally. Their research topics were so closely related that they kept presenting at the same sessions of the same conferences: her on the medical side, him on the engineering side.
“I distinctly remember Morten walking up to me after one of my first presentations and telling me he could write a program to automatically count the number of activated leukocytes on an intravital microscope video clip — something I had spent painstaking months doing manually alone in a dark room as a medical student,” Hanna Jensen said. “I always joke that it was the moment I knew I’d marry him.”
They’ve since collaborated on multiple projects, including the current Department of Defense grant, a vector flow imaging study on pediatric patients to create detailed images of the internal structure and blood flow of babies’ hearts. The pair has two children, Matilda and Lukas.
“We figured out we can constantly learn from each other and fill gaps on the continuum of biomedical research, and we respect each other’s areas of expertise, so we rarely clash on professional topics,” Hanna Jensen explained. “Morten is the idea generator, and I am the organizer…. Plus, when a big deadline is looming, we can gear the entire family schedule toward making it happen.”
Hanna Jensen
Coda
In describing how the heart functions, Jensen offered a quick tour, showing how blood comes in from the lungs through the left atrium, passes through the mitral valve, which prevents it from flowing backward, then enters the left ventricle and pushes on to the aorta. From there it circulates through the body until it finally returns to the heart through the right ventricle and is sent back to the lungs for more oxygen.
He concludes: “So it’s pretty neat, the way it works.”
He’s just got a few more things to fix.