A team of scientists including McGowan Institute for Regenerative Medicine
faculty members Cameron Riviere, PhD, Adjunct Assistant Professor, Department of Rehabilitation Science and Technology, University of Pittsburgh, and systems scientist for both the Carnegie Mellon University’s Robotics Institute and the Institute for Complex Engineered Systems, and Marco Zenati, MD, Director of the Minimally Invasive Cardiac Surgery Program and Professor of Surgery, University of Pittsburgh School of Medicine, have created a robotic device that can be inserted onto a heart using minimally invasive surgery to deliver medical treatment. Resembling a robotic caterpillar, the device developed by Dr. Riviere and colleagues at Carnegie Mellon University can crawl across the surface of a beating heart, delivering drugs or attaching medical devices. The 20-millimeter-long robot -- called HeartLander -- has two suckers for feet, each pierced with 20 holes connected to a vacuum line, which holds it onto the outside of the heart. By moving its body segments it can crawl across the heart at up to 7 inches per minute. Surgeons keep track of the device using X-ray video or a magnetic tracker, controlling the movements via a joystick.
Presently, during open-heart surgery a surgeon must cut through the sternum and then pull back the ribcage to reach the heart. Another option is an endoscopic technique in which the surgeon operates through small incisions in the chest while the heart is still beating. In 2001 Dr. Riviere thought robotics could make heart surgery less traumatic. He approached Dr. Zenati who was well aware of the uses and limitations of surgical robots: Dr. Zenati performed the first robot-assisted, beating-heart coronary bypass surgery in the United Sates.
It was during the robot development, in order to gain additional perspective on cardiac surgery, Dr. Riviere became a frequent visitor to Dr. Zenati's operating room. Observing procedures there sparked in him a research analogy. Rather than a robotic arm or hand-held device trying to impose its will on the beating heart, why not inconspicuously land a robot directly on the heart's surface just like a lunar module landing on the unpredictable surface of the moon? Hence, HeartLander.
Today, after over 6 years of innovation, HeartLander is around the size of a battery and in animal trials. During a recent surgical procedure on a pig, HeartLander not only moved independently to a series of predetermined points on the epicardium, it also successfully navigated to the heart’s posterior—a task requiring it to crawl upside down with the weight of the heart pressing the robot against the spine.
The practical applications for HeartLander have surgeons excited. A recent test demonstrated that HeartLander is capable of placing pacemaker electrodes anywhere on the epicardium—a far greater range than existing techniques allow. The robot could be outfitted with a probe to allow surgeons to treat arrhythmia by ablating damaged or malfunctioning cardiac tissue. Multiple tests, including HeartLander's journey to the underside of the heart, have shown HeartLander to be effective in delivering myocardial injections using its on-board needle. Dr. Riviere predicts it could deliver therapy like stem cell treatments to regenerate damaged heart muscle. Also, because the minimally-invasive HeartLander surgeries don't require lung deflation, they could be performed under local, rather than general, anesthesia. The phrase Dr. Zenati explains as potential "outpatient heart surgery."
With all that has been accomplished, there’s more testing to be done. Dr. Riviere estimates it will be another 3 to 5 years before HeartLander is set to land on a human heart.
Illustration: HeartLander. –The Robotics Institute, Carnegie Mellon University.
The Tartan (02/02/09)
Carnegie Mellon Today (01/2009)
HeartLander, The Robotics Institute, Carnegie Mellon University
Bio: Dr. Cameron Riviere
Bio: Dr. Marco Zenati