It might not actually cause harm or strange effects to people's bodies, but I'd certainly feel better if it was tested and used by doctors in a hospital and not some "spa" since those tend to be poorly regulated and where all kinds of quackery takes place (https://www.aafp.org/afp/afp-community-blog/med-spa-industry...).

The safety of the device itself is a concern, but so is the trustworthiness of the output. Midjourney already has some very questionable history with medical imagery (like this totally legit image of rat testicles published in "Frontiers in Cell and Developmental Biology" https://upload.wikimedia.org/wikipedia/commons/c/cc/AI_gener...)

From my understanding of the post, the waves that are created are smaller than light waves, and there's no evidence that light waves, sound waves or sub-sonic waves have any aneurysm-causing effects.

(I researched more and found in the video a value) The waves are 50 nanometres, and this is basically the equivalent of having a full body ultrasound. We've been doing baby ultrasounds for decades with no ill effects, so I can't imagine this being different

We already ultrasound babies in the womb, so one would hope this has been studied.