Researchers at Worcester Polytechnic Institute (WPI) have developed a flexible optical fiber that can be guided through a medical endoscope into the larynx to destroy tumors on hard-to-reach vocal cords. This advancement could expand outpatient laser treatment options for patients whose only option is surgery under general anesthesia.
Researchers reported that in tests using a 3D-printed replica of the human larynx, they were able to reach about 81% of 70 targets that were unattainable through outpatient treatment.
“Some people, such as patients with heart disease, may not be able to undergo general anesthesia or traditional laser surgery for laryngeal growth,” says Loris Fichera, associate professor in the Department of Robotics and leader of the research team that developed the new fiber optic technology. “Improved medical devices could address this issue by giving some patients the option of undergoing laser treatment in the office under light sedation.”
The researchers’ device is a flexible optical fiber threaded through a thin-walled nickel-titanium sheath, 1.6 millimeters in diameter, with a notch that allows it to bend. The sheath is thin enough to fit into an endoscope, a tubular device with a light and camera at the tip. Surgeons insert an endoscope into the body to examine tissues, organs, and structures.
Once inside the endoscope, a hand-held control guides the sheath and optical fiber to a site within the voice box (tissue also known as the vocal cords), and a pulse of light destroys the growth.
Laser surgery on the vocal cords is usually done to remove small benign or precancerous growths, such as calluses or polyps, that can leave patients with a hoarse voice. For professional singers and speakers, this condition can threaten their livelihood. Allergies, underlying medical conditions, smoking, and overuse or misuse of the voice can affect growth development.
Most procedures are performed in a doctor’s office and typically involve passing an endoscope through the patient’s nostrils with the vocal cords numbed with a cooling spray. Patients who have difficulty reaching growth can be treated in the hospital under general anesthesia.
To test their design, the researchers used 3D printing to build an anatomically correct model of a real human larynx. They plotted 70 points on the model that could not be reached with non-steerable fiber optics and used the steerable tool to reach 57, or about 81%, of the targets.
The findings suggest that the device created by Fichera’s team has the potential to expand office-based procedures for laser surgery on the larynx, but Fichera says the device requires further research and development. Rigid 3D-printed models cannot reproduce the movements that occur during patient treatment, and the device currently requires two operators to work together. Improvements could allow a single operator to use the device.
Much of the basic research has been completed. We are planning follow-on projects to make improvements that allow optical fibers to be bent in different directions and curved to reach more locations. Ultimately, our goal is to help as many patients as possible by expanding in-office treatment options. ”
Loris Fichera, Associate Professor, Department of Robotics, Worcester Polytechnic Institute
The study was presented to the American Society of Medical Engineers. medical device journal. In addition to Fichera, co-authors are Alex Chiluisa, M.A. ’20, Ph.D. ’24; Undergraduate student Kang Chan. Yao Shen, MS ’18, PhD 25; PhD student Lucas Burstein; Yuxiang Liu, Associate Professor, Department of Mechanical and Materials Engineering. Thomas Carroll, associate professor of otorhinolaryngology at Harvard Medical School.
Fichera’s research focuses on using robotics and computer science to advance technologies used in medicine, particularly surgery. He received a prestigious Career Award from the National Science Foundation for developing technology for a new class of surgical robots that can treat diseases without cutting or touching human tissue. He is also part of a team at WPI that is developing technology for flexible robotic arms that can grasp, lift, and carry objects. He is co-inventor of a patent protecting a flexible, articulating surgical laser probe for laryngeal surgery.
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Worcester Polytechnic Institute
Reference magazines:
Chileisa, A.J.et al. (2026). Steerable optical fibers for office-based laryngeal laser surgery: Design, development, and experimental evaluation in a phantom model. medical device journal. DOI: 10.1115/1.4070782. https://asmedigitalcollection.asme.org/medicaldevices/article-abstract/20/3/031001/1229818/Steerable-Optical-Fiber-for-Office-Based-Laser?redirectedFrom=fulltext
