Student develops device to help eye surgeries
Sight is the predominant sense in the perception of the world. At the early age of 6, it has already developed into the most dominant of the five senses. But what if we slowly lost our ability to see? Our lifestyle would change drastically; anyone who has tried walking around with closed eyes would understand. Although we would probably become accustomed to a lack of vision, it would still complicate many daily tasks and leave us limited in our activities.
Diseases of the eyes are numerous and have many causes; for example, people with diabetes may develop diabetic retinopathy in which blood vessels in their retina are damaged. This may cause blood to leak into the eye, blurring and blotting vision, causing a condition known as macular edema. Fortunately, we live in an age of expanding knowledge and collaboration in robotics, medicine, and surgery. It is because of these diseases that many of today’s leading researchers and robotics scientists are motivated by robotic surgery. One such scientist is Brian Becker, a current Ph.D. student at Carnegie Mellon working in the field of robotic surgery. Becker is currently working on the Micron project under his adviser, Cameron Riviere.
Micron, designed by staff engineer Robert MacLachlan, is a handheld, pen-shaped device used in robotic eye surgery that is planned for use with retinal surgery therapy.
While a person holds it like a pen, it has a small tip that can move in three dimensions. Using stabilization software, the device can minimize unwanted hand movements, or tremor, caused by natural hand unsteadiness.
“Everybody has a little bit of tremor in their hands,” Becker said. “However, microsurgeons often deal with structures that are as tiny as the diameter of a human hair or even smaller. A system such as Micron compensates for tremor to increase the accuracy of surgical movements.”
Micron will be used in laser photocoagulation, which is a process in which heat from a laser is used to seal blood vessels that may be leaking or abnormal. The treatment may completely seal blood vessels on the retina, or it may slow the growth of new abnormal blood vessels. Thus, Micron will be able to treat diseases such as diabetic retinopathy. Micron is attached to sensory equipment that will be used in the application of laser burns. As Becker explained, there are motors between the handle grip and the end tip, and its position will be tracked with high-speed optical tracking from stereo cameras mounted on a microscope. Micron will thus be able to track its own movements so as to apply the burn to the correct place, correct for hand tremor, and stabilize the instrument. Becker explains the benefits of such an advanced technology: “The Micron concept can be used to place laser burns accurately, inject medicine into veins, avoid accidentally bumping into delicate tissue, and increase precision of operations by scaling down movement within the workspace. The surgeon exerts macro control while Micron aids in the micro movements.”
Minimizing tremor has always been desired during medical procedures. Micron differs from other devices because it is cheaper, and leaves the surgeon in full macro control of the device. Other devices developed require more extensive training, are less intuitive, and cost over a hundred times more. Tests have already been performed with Micron, using a seven-by-seven grid of squares 650 microns apart (about a quarter of a penny in size), and Micron was noticeably faster and more accurate than the manual process.
“Most of our existing experiments have centered around simple tasks such as pointing, tracing, and other basic movements used in surgery. In these tasks we have shown roughly 20 percent improvement in accuracy,” Becker said. In the future, the group plans to test Micron on real animal eyes.
Micron is still in its developmental stages, but it has a bright future. Becker, who is researching the control of Micron in useful ways, would like to expand the usefulness of the instrument. Currently, Micron is adept at accuracy in a small area; Becker wants to expand its range of motion to handle larger tasks, such as over a thousand accurate laser burns and a greater speed of operation. He hopes to achieve other goals for Micron, including the ability to inject medicine into tiny retinal veins, and to expand its scope into more than just retinal surgical procedures. Micron was developed to benefit medical science. Becker revealed his optimistic outlook on the device’s future, saying, “It is supposed to be as interchangeable as possible with existing equipment and procedures, yet superior in existing approaches by providing increased accuracy to enable procedures that are today considered impossible.”