Common orthopaedic procedures, such as spinal fusion, require the accurate positioning of a thin metallic wire to guide the positioning of a fixating screw. However, the surgical procedure is often hampered by deflection, bending and even breakage of the guide-wire, which then requires repair while complicating and prolonging the recovery of patients.
“This is a significant challenge”, says Meir Liebergall, head of the Department of Orthopedic Surgery at Hadassah Medical Center, Jerusalem, Israel, “as complications in guide-wire positioning could lead to revision surgeries and increase hospitalisation time and cost.”
To address this challenge, Liebergall partnered with a multidisciplinary team of medical doctors, along with engineering and business students, from the BioDesign: Medical Innovation program at The Hebrew University, Jerusalem, Israel.
The team realised that a system that provides real-time indication of deflection or bending of the guide-wire should allow a surgeon to be able to adjust the procedure before damage occurs.
The team developed BendGuide, an opto-electronic drilling system that monitors and detects minute changes in guide-wire trajectory during surgery. It allows surgeons to correct drilling trajectories during the procedure itself. The system eliminates guide-wire bending or breakage and significantly reduces operation time and enhances safety.
“This is an elegant technological solution to a complex problem,” says Yaakov Nahmias, director of The Hebrew University’s Alexander Grass Center for Bioengineering and the BioDesign program. “The group model and proof-of-concept experiments showed they could detect even miniscule changes in guide-wire trajectory.”
BendGuide uses a fibre bundle with a reflecting laser beam that enables detection of small deflections in wire trajectory. At a fully-aligned state, the beam power hits the centre of the detector array. When deflected, mirror misalignment causes the power to spread differentially across the fibre bundle.
The interdisciplinary team which developed BendGuide include Giora Weisz, Chairman of the cardiology department at Shaare Zedek Medical Center, Jerusalem, Israel; Hadar Shor, a student at The Hebrew University’s Jerusalem School of Business Administration and a fund manager for Israel’s Ministry of Economics; and Kuti Uliel and Michal Zimerman, graduate students at the Alexander Grass Center for Bioengineering.
BioDesign: Medical Innovation is a multi-disciplinary, team-based approach to medical innovation, created by the Hebrew University of Jerusalem and its affiliated Hadassah Medical Center. Sponsored by Boston Scientific and the Terumo Medical Corporation, the program takes outstanding medical fellows, bioengineering and business graduate students, and tutors them in the science and practice of bringing a medical innovation to the market. The program is directed by Yaakov Nahmias, director of the Alexander Grass Center for Bioengineering at the Hebrew University of Jerusalem, and Chaim Lotan, director of the Heart Institute at Hadassah Medical Center.