In medicine, the eureka moment rarely happens. Sometimes medical advances gain momentum from a simple gesture like an introductory email or a serendipitous meeting. Just ask Ron Alterovitz, PhD, assistant professor of computer science and head of the Computational Robotics Research Group in the Department of Computer Science at UNC.
Since arriving in Chapel Hill in 2009, Alterovitz’s group has been investigating new algorithms that can enable robotic tentacles to achieve depth and precision inside the human body. One of his devices – steerable needles he co-created as a graduate student at UC-Berkeley – is being developed to treat liver and prostate cancers.
Now Alterovitz is focused on a new surgical device – a snake-like, robotic set of concentric nested tubes made of nickel titanium. The device can be deployed from the tip of a bronchoscope, allowing physicians to reach farther than ever into the lungs to diagnose abnormal growths called nodules. It can also be deployed via the nose to surgically access tumors in the brain or nearby structures in the head. The robotic device has the potential to move through the body so precisely that it can avoid anatomical obstacles and reach its target within a millimeter.
These interdisciplinary, NIH-funded projects have been of interest to School of Medicine faculty members Richard Feins, MD, professor of surgery in the division of cardiothoracic surgery, and Brent Senior, MD, Nathaniel and Sheila Harris Distinguished Professor of Otolaryngology.
After receiving an email from Alterovitz upon his arrival at UNC, Dr. Feins, an early user of the superDimension lung navigation system, was immediately interested in hearing what Alterovitz had to say. “As surgeons, most of what we do in terms of treatment involves getting where we need to go, so when Ron came to me with the concept of a steerable catheter that could get anywhere he preprogrammed it to go, it was exciting,” says Dr. Feins.
As surgeons, most of what we do in terms of treatment involves getting where we need to go, so when Ron came to me with the concept of a steerable catheter that could get anywhere he preprogrammed it to go, it was exciting.
Dr. Senior’s work with Alterovitz didn’t involve an email; it began at church. Dr. Senior was mentoring a student of Alterovitz’s at church when the two got to talking about their work at UNC. It soon became clear to Dr. Senior that he should meet Professor Alterovitz.
“I was excited to hear what he was doing because it really is exactly what we need to be thinking about for the future of what we do in skull-base surgery,” says Dr. Senior.
“Think about the airway as a tree,” says Dr. Feins. “The limbs get smaller and smaller as you fan out. You’d like to climb out to grab an apple off one of the branches, but you can only go so far before you have to stop because the limbs are too small and will break. That’s sort of what we’re talking about with reaching peripheral lung lesions.”
Diagnosing peripheral-zone lung cancer is difficult. The nodules can be reached with a CT scan and biopsied, but doing so runs the risk of collapsing the lung. Furthermore, even when the lesion is reached, the amount of tissue that can be gathered may be limited, and therefore the sample is potentially inaccurate.
Snake-like robotic needles, attached to and deployed by the bronchoscope, may provide more accurate diagnoses. As curvilinear devices that can be programmed, the needles can snake their way through the parenchyma of the lung to access nodules in the peripheral zone, striking their target with precision.
“If the nodule identified in the CT scan is on the peripheral zone, and the bronchial tubes are so small that you can’t use existing devices like the superDimension, then that’s where these robots can work,” says Alterovitz.
Early-stage diagnosis through biopsies of peripheral nodules has the potential to save lives. And in the immediate term, that’s the focus of Alterovitz and Dr. Feins. The long-term goal, however, is to actually treat the tumors. Dr. Feins uses the analogy of the early days of cardiology.
“Cardiology was primarily a diagnostic specialty,” says Dr. Feins. “They did angiograms and saw what was wrong with the patient, and then they’d have to send the patient to the surgeon. Eventually they found therapeutic options. They could dilate the arteries or put stents in the arteries. Those therapies changed the whole dynamic. I think it’s possible that if we can get the technology to precisely where we need it to go, not only can we make a diagnosis, but we can add therapeutics like localized radiation, localized chemotherapy, or even localized freezing or radio-frequency ablation.”
High-priced real estate
The pituitary gland sits squarely in the middle of the skull. Flanking it on either side are the carotid arteries, which control blood flow to the brain. The cranial nerves surrounding the pituitary control vision, movement of the eyeballs, sensation to the face and jaw, and other functions critical to everyday life.
“I tell my residents that we’re dealing in high-priced real estate,” says Dr. Senior. “You have to be very exact. Critical nerves are a millimeter or two from the target area we’re trying to reach.”
According to cadaver studies, tumors in this region are common. Although rarely cause for concern, some abnormalities require operations. A century ago, surgeries in the pituitary were highly invasive, requiring the face to be fileted open. The procedures resulted in high mortality and complication rates. Today, after a series of advances, endoscopic procedures, which include dissection inside the nasal cavity, are relatively safe. UNC Hospitals performs roughly 100 such procedures per year.
Although utilizing the surgeon’s fine finger motion has proved effective thus far, there’s room for further improvement, according to Dr. Senior. Robotic technology coming from the Computational Research Group is poised to allow surgeons performing this procedure to reduce dissections and increase precision within the target area.
“The beauty of Ron’s work is that we may be able to go through natural openings and do minimal expansion of them, and then pinpoint directly into where the tumor is located by using a roadmap system,” says Dr. Senior. “Because the robot has such fine ability to position and move instruments, theoretically it would be safer as well.”
The beauty of Ron’s work is that we may be able to go through natural openings and do minimal expansion of them, and then pinpoint directly into where the tumor is located by using a roadmap system. Because the robot has such fine ability to position and move instruments, theoretically it would be safer as well.
The device can be outfitted with a variety of applications at its tip, including a camera, gripper, suctioner, and irrigator. Up to four devices with different tips could be deployed simultaneously during a procedure, with the idea that the devices could be used together by the surgeon as part of a treatment of the tumor.
Dr. Senior is optimistic about the possible advances. “Our goal with these surgeries is 0 percent mortality, 0 percent morbidity,” he says. “We don’t want any complications. Of course, we’ll never reach that, but I think that the robot will help to move us in the right direction, and it will be a stepping stone into other areas of the skull base as well. We have seen amazing advances in these surgeries in the last 20 years, and I believe that the robot will keep chipping away at those numbers and continue to improve the quality of life of our patients after the procedures.”
Learning new languages
As the collaborators continue to trade technical expertise to advance their work, Alterovitz and his lab scour medical journals for the relevant research that will aid them in the medical applications of their robots.
“Building up your vocabulary takes time, but it’s required to get up to speed,” he says.
Alterovitz talks at length with the physicians to learn about the specific procedures. Despite the challenges of learning another discipline, the give-and-take provides all parties with a better understanding of each other’s work.
“I’m in awe of what Ron does,” says Dr. Feins. “For Ron, the world of computer science is very easy. But the medicine part of what we’re doing – a lobectomy, for example – can be difficult for him to understand. I’m exactly the opposite.”
Dr. Feins and Alterovitz maintain an open dialogue. They sometimes speak for hours, hashing out the complications and challenges of their project. For them to be successful, it’s essential, Dr. Feins says, for Alterovitz to feel comfortable asking questions.
“I don’t want him to have any fear about asking, ‘What do you mean by this?,’” says Dr. Feins. “I might have to tell him you can’t put a hose that big down the airway because the patient won’t be able to breathe. And he may have to tell me that we can’t make a right-angle turn. It’s a good back and forth.”
Alterovitz enjoys the process.
“That’s the fun part about this line of work – learning about these procedures, how the physicians do them, what’s important to them as they do them, and how we can translate what they want to do into technology,” says Alterovitz.
Alterovitz isn’t a complete newcomer to medicine. After finishing his PhD at Berkeley, he received an NIH award that gave him the opportunity to work in a medical research group at UCSF Medical Center, where he was embedded with medical physicists and radiation oncologists. Dr. Senior has watched Alterovitz learn medical concepts and admires his commitment to building his medical knowledge base.
“I have to say, I was honestly impressed that he has taken it as far as he has already,” Dr. Senior says. “He has a lot more insight into the anatomy and our procedures than I would expect a computer scientist to have. He’s really done quite well in terms of getting a good, established knowledge base.”
At the start of their collaboration, Dr. Senior invited Alterovitz’s students into the cadaver lab to perform dissections. He showed them the current endoscopic instrumentation so that they could get a sense of the distances, the tightness of the space, and the current complexities of the surgeries they do.
“I think that was a very valuable thing for them,” continues Dr. Senior. “Their knowledge of the anatomy is sort of like a black box with some obstacles in it. So we were able to give them a view of the anatomy in a very true and biologic and physiologic way.”
Alterovitz acknowledges that building his medical knowledge is a work in progress.
“I’ve been learning as I go,” he says. “I almost wish I had a little more formal training. But it’s been helpful that I have great collaborators.”
Culture of collaboration
Prior to arriving at UNC, Alterovitz’s collaborative work with a UC-San Francisco Medical Center team and Johns Hopkins University mechanical engineers led to the development of steerable needles for improving the precision of prostate brachytherapy. When needles are inserted – and located accurately – in the prostate gland, radioactive seeds are deployed. The seeds distribute high doses of radiation to the tumor and only low doses to the surrounding healthy issues – so low that side effects are minimal.
Although UCSF Medical Center was located just across San Francisco Bay, Alterovitz recalls the challenges presented by the distance between Berkeley, where he lived and worked, and his collaborators near Haight-Ashbury. He had to take both a train and a bus any time he traveled to meetings with them, and it was difficult to set up gatherings spontaneously.
Such logistical impediments, Alterovitz admits, can slow research down. He has found the opposite situation at UNC, which he considers the perfect location for his work.
“A big reason this research can go forward is that here the School of Medicine and the College of Arts & Sciences are located on the same campus,” says Alterovitz. “It’s a simple thing, but it’s a huge benefit for this line of research because I can simply walk to the hospital to meet with my clinical collaborators, and we can even meet somewhat spontaneously.”
Dr. Feins feels fortunate to have such a close connection to other areas of the university.
“Proximity is critical,” says Dr. Feins. “Traditionally, in highly creative places, you have a critical mass of people that are in proximity to each other. Look back at the enclaves of painters in France, for example.”
Being geographically close has allowed Dr. Senior’s lab meetings with Alterovitz and his students to occur often.
“We’re literally right down the road from each other – and my lab is halfway between us,” says Dr. Senior. “So we’ve been able to meet very easily. It’s been absolutely great.”
Proximity alone doesn’t foster a collaborative atmosphere – silos often stand side-by-side and never meet. Rather, a shared spirit of creativity found across the campus helps to break down those silos and bring different sets of expertise together.
“UNC has a tremendous culture of collaboration,” says Dr. Feins. “We’re able to collaborate very easily and readily, and without a lot of the things that other centers worry about, such as what’s patentable. It’s vitally important to have that proximity and culture and even, some would say, architecture – places where you can get together and talk – to foster that. That’s what allows for a creative environment, which is the reason we’re all here.”
Dr. Senior echoes those sentiments.
“I’ve worked at a lot of places,” says Dr. Senior, “and the collaborative spirit that I get from the people here is fantastic. Ron is an expert in robotics and the computer science required to make these advances possible. I’m an expert at the disease and getting us into the area where the tumors are located. My neurosurgeon colleague upstairs is the expert at the actual tumor. It’s all of us bringing our expertise together that makes advances in medicine possible.”
by Zach Read