Bonnie Chan
A Holmium laser is a holmium-doped fiber pulsed mode laser that is highly absorbable by water and has a shallow penetration depth. As such, there is high potential for its use in biomedical engineering projects such as kidney stone ablation. In a kidney stone ablation project closely related to this study, the laser will be set to do short pulses to generate a bubble in a water tank containing a kidney stone phantom. Upon the bubble’s collapse, it releases a shock wave that theoretically induces breakup of the artificial kidney stone. It has been found that certain laser settings perform ablation better than others and this study will investigate the possibility that it is due to the absorbance of the kidney stone before and after ablation.
Studies on laser kidney stone ablation typically use kidney stone phantoms, BegoStones, to save on cost and time. While BegoStones are known to have mechanical properties similar to kidney stones, their optical properties have yet to be explored. To lend depth to laser kidney stone ablation studies, this project will investigate BegoStone optical properties, specifically their absorption coefficient. The background research phase of the project is ongoing, but tests will be performed with the use of an integrating sphere to measure the absorption and reflection characteristics of the stone. After the laser is fired towards the BegoStone, the integrating sphere will collect the scattered laser light from the stone by reflecting the light inside the sphere until it makes its way to a photodetector. The tests will be done at different laser powers and pulse settings so as to analyze the scattering at each setting. The absorption coefficient of BegoStone may be a useful parameter to consider in future kidney stone ablation studies.
Comments
Good job. Aside from kidney stone ablation, are there other related applications for this type of laser? —Rob Reichle
Absolutely! In the same lab, work on laser microbiopsy is also being done for use in diagnostic medicine. A Holmium laser can remove smaller pieces of tissue than a regular biopsy, reducing time, pain, and tissue since a regular biopsy often removes more tissue than is necessary. —Bonnie Chan
This sounds like very promising research. Is the thinking that this could reduce pain for kidney stone patients, or reduce the need for surgical intervention? —Jeanette Herman
The idea is to reduce the need for surgical intervention by breaking up large kidney stones, although reduction in kidney stone size would likely reduce pain as well. —Bonnie Chan