Optical guide aims to keep orthopaedic procedures right on target
A multidisciplinary team from the Hebrew University has created a system that provides real-time indication of deflection or bending of the guide-wires commonly used in orthopaedic procedures.
The thin metallic wires used to guide the accurate positioning of fixating screws during hip and pelvic fracture surgery, and spinal fusion, often deflect, bend and even break during surgery, leading to complicated repair procedures and prolonged recovery for the patients.
To address the challenge, Meir Liebergall, head of the department of orthopaedic surgery at Hadassah Medical Center, partnered with a team of medical doctors as well as engineering and business students from the university’s BioDesign: Medical Innovation programme. The researchers identified that by creating a system that provides real-time indication of deflection or bending of the guide-wire, the surgeon will be able to adjust the procedure before damage occurs.
BendGuide, an opto-electronic drilling system that monitors and detects minute changes in guide-wire trajectory during surgery, allows surgeons to correct drilling trajectories during the procedure itself. The system eliminates guide-wire bending or breakage and significantly reduces operation time while increasing safety.
“This is an elegant technological solution to a complex problem,” said Yaakov Nahmias, director of The Hebrew University’s Alexander Grass Center for Bioengineering and the BioDesign programme. “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 market for computer-aided navigation systems for surgery is growing fast. The potential market is estimated at $500 million annually in the USA alone.
Source: The Hebrew University of Jerusalem
Caption: Students at the Hebrew University’s BioDesign programme developed an opto-electronic drilling system that detects minute changes in guide-wire trajectory during surgery. Credit: The Hebrew University of Jerusalem