It's not the size of a backpack but my wife did home hemo dialysis with a machine that had a handle and was portable. We even took it on trips a few times. I forget the weight, but, from memory, was around 10 pounds / 4.5 kg I think. Wife has had a transplant so my home hemo experience is from a few years ago. It may have changed since then.

The machine's portability wasn't the only factor. Needed a clean space to set up. There was a second machine hooked up to the house water lines. It would be used to create dialysate which was pumped into the dialysis machine. You could travel without the water pump, but to replace it, you needed these massive disposable bags of dialysate. Each bag was heavier than the machine itself and they were essential.

I guess with car trips, you could take the pump too to generate dialysate on site but it wasn't designed for portability as much as the main dialysis machine was. Was heavier. We kept it on rollers.

There were other supplies needed too. Saline bags. The dialysis machine had one-time use cartridges that were quite convenient but took up a fair bit of space. All added up to considerable bulk.

We only used the machine at distant locations when we knew we were going to be there for a week or more. One factor that made things a little easier was the the dialysis company was willing to deliver supplies to wherever we were, as long as it was within the US. We didn't have to take weeks worth of supplies. But we did have to take enough supplies to get through the first few days before delivery.

Vacations were rare but doable if we were going by car or if there was a dialysis center at the location. I guess we could have flown with the machine but we didn't trust airline baggage handlers enough to risk it.

There is peritoneal dialysis, which is pretty portable and doesn’t filter the blood (it exchanges peritoneal fluid, which is a lot less invasive). It’s actually quite fascinating how simple the machine is — and in fact, the simplest version of the machine is literally two bags and a couple of valves, completely operated by gravity. Everyone is not eligible for this type of dialysis, however. I don’t remember why.

Oh, also, if you do peritoneal dialysis, it’s daily, whereas hemo dialysis is generally two or three times a week.

My dad tried out a 24/7 IV for a heart medicine. The pump and a bag with a 1 week supply of the medicine fit in a fanny pack sized bag. It worked well, but he's 90 and pulled out the IV line in the middle of the night. He didn't remember doing it. So we decided to discontinue the meds. But I'm sure it would have been fine for a younger, less confused person. Just a bit inconvenient for showering, etc.

If you've ever been to a dialysis center when a patient accidentally pulls out the line you can imagine why. They are thick lines that will rapidly make a huge mess.

I guess though a backpack version probably could be more like an always attached glucose device with just a tiny line.

There are portable ones you can self administer overnight.

A combination of not quite feasible, not quite usable if created, not quite safe.