Ask HN: How does one begin working with medical ultrasound?

My goal is to find some way to build an app or two that on top of video feed data sent out from medical grade ultrasound. I'm thinking the kind used for precision IV implant/pregnancy/etc. Anyone have experience with this?

Ideally there is a simulator to run on my computer, but if not I could invest in a piece of equipment. ebay seems to have affordable options, but there are many options so please share if you recommend any specific equipment. I assume the more hackable the better? Please let me know if I'm off-base on that as well.

After a few days of searching it seems so niche and proprietary that I can't even really tell if there's a standard for ultrasound data. If it's all proprietary, anyone know how to go about teaming up with people in the industry?