The NxStage System One (NxStage) has been in use by patients for several years.
The Tablo (Outset Medical) was fairly recently approved by the FDA in the U.S.
Baxter was developing a machine called Vivia, but decided not to pursue development.
Home Dialysis Central has information about what's in the pipeline related to dialysis. It includes more than just machines.
Here's info on an implantable bioartificial kidney:
There have been clinical trials in UK and Seattle, WA with the wearable artificial kidney: