Femtosecond laser used in ultra-fast, ultra-accurate laser scalpel
The practice of surgically removing diseased or damaged tissue within the body is something of a trade-off – quite often, some of the surrounding healthy tissue will also end up being removed in the process. In highly-sensitive areas such as the brain or spinal cord, where a fraction of a millimeter either way can have huge consequences, sometimes surgery is deemed to be just too risky. A newly-developed endoscopic laser “scalpel,” however, looks like it could lower those risks considerably.
Developed by a team of researchers from the University of Texas at Austin, the flexible device is just 9.6 millimeters in circumference and 23 mm long – it’s designed to be mounted on the end of an existing endoscopic cable. Among the off-the-shelf parts contained within its 3D-printed housing are a miniature microscope, a femtosecond (ultra-fast) laser, and a 750-micrometer MEMS (micro-electro-mechanical system) scanning mirror. It also incorporates a special fiber, which routes light pulses from the laser out through the microscope.
Initially, the microscope is used to target problematic tissue, via a technique known as two-photon fluorescence. This involves the use of infrared light, that can penetrate up to one millimeter into living tissue. The device is so precise that it can reportedly target individual cells or even parts of cells, such as nuclei.
An image taken with the probe’s two-photon fluorescence microscope shows cells in a 70-micrometer thick piece of vocal cord from a pig (Image: Ben-Yakar Group, University of Texas at Austin)
Once the tissue has been targeted, the laser delivers pulses of light a mere 200 quadrillionths of a second long. These are sufficient to remove the unwanted tissue, yet so brief that they leave adjacent tissue unharmed.
So far, the system has been lab-tested on pig vocal chords and the tendons of rat tails. Although it is ready to move into the commercialization stage, the scientists state that at least five years of clinical trials will be necessary before it’s approved for general use. They will be presenting their research next week, at the Conference on Lasers and Electro Optics in San Jose, California.
Source: The Optical Society