Be interested to know if this is related to the same process/technology that Midjourney announced last week[0]

0. https://www.midjourney.com/medical/blogpost

Unpaywalled link to the paper: https://www.semanticscholar.org/reader/ef7ae3bff634710f87124...

This is similar only in using an array of off-axis ultrasound tomography receivers but otherwise unrelated in that it's a serious publication with detailed information demonstrating potential medical utility. Near as I could tell, Midjourney Medical is an idea for a trendy spa treatment dressed up to look sci-fi cool. It's based on a repackaging of 40 of the exact same chip in Butterfly's handheld, full contact USB pocket-sized scanner which plugs into a mobile phone and is already available.

The CalTech team who wrote the Nature paper appears to be using an array of Olympus transducers equipped with their own custom lenses and a rotating emitter. Notably, the CalTech paper is focused on evaluating potential clinical benefits.

Yes. IIRC David Garrett (the first author of the Nature paper) also worked at Midjourney in the intervening period.