Lasers provide precise, contact-free cutting perfect for surgical procedures, yet they struggle with hard tissues like bone due to slow speeds and limited depth. A team at the University of Basel has pioneered a technique that achieves significantly deeper and quicker cuts using a surgical laser compared to earlier systems.
Transforming Bone Surgery Tools
Standard bone surgery relies on saws, chisels, and drills. Lasers stand to revolutionize this by eliminating mechanical pressure, minimizing microcracks, and allowing intricate cuts ideal for inserting joint implants, such as custom 3D-printed versions. While lasers excel in soft tissues, bone cuts previously maxed out at 2 to 3 centimeters—too shallow for many applications like joint replacements.
The Key Innovation: Redesigned Laser Beam Profile
Researchers led by Dr. Ferda Canbaz from the University of Basel’s Department of Biomedical Engineering optimized the laser beam’s energy distribution. Conventional beams follow a Gaussian profile, peaking intensely at the center and fading toward the edges, much like a flashlight’s glow. The new “top hat” profile delivers uniform energy across the entire beam before a sharp drop-off at the edges.
“Increasing the laser beam’s energy isn’t ideal, as it risks charring bone and impairing healing. Instead, we modified the laser’s shape—or more precisely, its profile,” stated Dr. Ferda Canbaz from the Department of Biomedical Engineering at the University of Basel.
“The even energy transmission allows the laser to cut more efficiently and rapidly,” explained Mingyi Liu, doctoral student and lead author.
Test Results on Bovine Bone
The team evaluated both profiles on cleaned bovine bone, using compressed air and water for cooling to avoid heat damage and maintain clarity. The Gaussian beam reached just 2.6 centimeters, while the top hat profile penetrated 4.4 centimeters.
“With standard profiles, cut walls absorb energy, starving the base and halting progress at certain depths. The top hat design circumvents this by redistributing energy away from the walls,” Canbaz noted.
Future Enhancements and Challenges
Current laser speeds lag mechanical tools—removing 0.4 cubic millimeters per second versus 11 for a saw—but mark the first viable depth for advanced procedures. Ongoing efforts focus on boosting speed, depth, and adaptation to in-body complexities, including tissue protection.
This research forms part of the “Miracle” project, supported by the Werner Siemens Foundation, and initiates the Innosuisse “Laser-Blade” collaboration with medical technology firm Smith&Nephew.
