it's hard to tell really, I'm not sure if that's what he's doing or not. Some of his stuff looks like it is and other stuff looks different.
He has the gas mixing chamber, the pump, and the injector plug.
I would just think if you could produce enough water droplets with an ultrasonic fogger and and mix that with hydrogen and ambient air or recirculated exhaust gasses all in one chamber you could have a simple design, and only need a type high pressure air pump that would pump all the mixed gasses direstly to the injector.
I also look at stan's injector and only see 1 ss line giong into it. Just makes me wonder.
Do you ahve stan meyer's pictures file with all of his pictures. Look at the resonant cavity picture. It shows the VIC box mounted on the side, and what I believe is a ultrasonic fogger that fits inside it as well, (those little prong looking things and the big magnet on the inner tube voltage zone that they sit on top of) I can't tell if there's an air input somewhere but most likely it gets mixed sooner rather than later. Stan meyer did mention the ambient air or exhaust gasses mixing with the hydrogen to reduce it's burn rate, and if you do all of them in the same container at the same time, you'll have a very safe mixture going to your engine.
That's my best guess hydro, hop it helps!