Microbubbles in Medicine

worksinprogress.co

32 points·Jimmc414··6 comments

They mention using an ultrasonic pulse to pop bubbles around a kidney stone.

In scuba diving, microbubbles are what many blame decompression sickness on. I wonder if it may be possible to attach some sort of ultrasonic beeper to periodically burst them somewhere safe?

The microbubbles in scuba diving that cause the bends are the ones trapped in joint space fluid. That fluid doesn't circulate at a useful rate, so unfortunately you can't really "burst them somewhere else" =(

While diffusion from joint space is perfusion limited, some work suggests ultrasound might increase that perfusion? By vasodilation and microvascular recruitment, from heating and shear stress on endothelial cells. With bubble vibration and cavitation as one source of stress.

Also, though perhaps not rate limiting, ultrasound might be able to mess with the N2 bubble boundary diffusion rate.

Caveats: Very not my field; no clinical practice; mostly animal studies; mostly musculature and not joint; and under-validated AI.

Meta: But I so very much enjoy surfing literature with AI. Even with AI's rich collection of interesting failure modes. They serve as fun added encouragement to keep you on your toes, and keep clear on the gradients of your confidence.

The method in the article is more similar to cavitation https://en.wikipedia.org/wiki/Cavitation You get small bubles of water vapor and after a short time it transform into liquid water and just dissappears.

In scuba diving the bubbles are made of Nitrogen, that can't dissappear. It must get slowly disolved in the blood and get out of the body in breath.

The article says they can be used to temporarily open the blood-brain barrier or open cell barriers. Could this also be a risk which allows pathogens to pass?

Before you know it someone will be using nanobubbles.

Reply on news.ycombinator.com