Laser in the Field of Medicine

[Bonnie]

I'm amazed how laser is used in medical practice. I wonder how laser can destroy a kidney stone while not affecting the other organs of the body where the laser passed through.

 

[CoherentRays]

I'm amazed how laser is used in medical practice. I wonder how laser can destroy a kidney stone while not affecting the other organs of the body where the laser passed through.

I've never heard of a laser being used in this manner. Are you thinking of lithotripsy where ultrasonic (high energy sound/shock) waves are used to pulverize the kidney stones?

Ed

 

[Ignis Fatuus]

I'm amazed how laser is used in medical practice. I wonder how laser can destroy a kidney stone while not affecting the other organs of the body where the laser passed through.

Dont quote me, but from what I've read they add micronized gold, or similar metal to the effected area. Then they use a laser with a wavelength that does not harm skin, but will break down the gold deposited in the tissue/stones. They've been working on this for a long time, in hopes to use it for tumors.

 

[Trevor]

I worked at a urological practice over the summer. Always interested me when the mobile laserscope truck would show up with one of the newer 120W systems.

-Trevor

 

[Woodsy]

Lasers have a whole host of applications in medicine. Usually a wavelength is chosen based upon the absorption and scattering properties of the target (hemoglobin (SP?) in the blood absorbs red the most, as might have been guessed!), and the power is chosen based on what process you want to achieve. For example, the process called photoablation is the rapid and localised vaporization of tissue, whereas other processes might be far more general and slower acting. Also some of the properties of the beam itself come into it, such as the coherence having a say in how small a spot size once focused will be etc.

Personally, I find the photochemical reactions used in treating tumors really interesting, where a light sensitive chemical is absorbed by the tumor, and light of a certain wavelength is aimed at it. the combination of chemical and energy from the light produces pure oxygen which is highly toxic and kills the tumor. Incredible stuff!

Lasers can indeed be used in Lithotripsy, where high energy pulses rapidly heat a small area causing thermal expansion, which in turn causes a shock wave to travel through the stone, breaking it up into small pieces.

W

 

[millirad]

Yeah, I can see how the coefficient of thermal expansion would allow the differing density of 2 molecule types to expand/contract at different rates which has a propensity to disrupt their chemical bonds. +1