In 2009, we had a look at the Wearable Artificial Kidney (WAK) concept that promised patients suffering from kidney failure an alternative to conventional dialysis. Now the tool-belt sized prototype has been granted approval for human testing in the United States by the FDA with clinical trials scheduled to take place in Seattle later this year.

The result of over a decade of development, the WAK was conceived by a team led by Victor Gura at the Cedars-Sinai Medical Center, Los Angeles and the David Geffen School of Medicine at UCLA. It’s a miniature dialysis machine small enough to be worn like a tool belt and is connected to the patient by means of a catheter. According to the team, with such a device, patients would no longer be spending time in long, boring static sessions, but could be out and about working or playing while the wearable unit cleaned their blood on the go.

Like a conventional dialysis machine, the WAK filters out waste products from the patient’s blood after their own kidneys have failed. But while a conventional dialysis machine is the size of a filing cabinet, and even a portable version is as large as a computer printer, the WAK weighs only 10 lb (4.5 kg).

This is very important because dialysis takes up to four hours at a time, three times a week, during which the patient is attached to the machine. And because conventional and portable machines need to hooked to the mains and need large amounts of water, that means the patient can do little more than sit in a chair the entire time.

In terms of its design, WAK is almost identical to larger dialysis machines, but by taking advantage of recent advances in batteries, materials, and miniaturization, the WAK team has been able to radically reduce the size of the wearable machine and the amount of water needed from 40 gal (151 L) to a pint (0.5 L).

So far, the WAK device is at the prototype stage and has undergone limited human testing in Italy and the UK, and is one of three proposals out of 32 candidates chosen for the FDA’s Innovation Pathway program aimed at streamlining the development of medical products. The tests will involve up to 16 patients with 10 to be selected for the full trial. This will involve 24 -hour tests during which the patients will be allowed to move around. During this, blood samples will be drawn and there will be a 28-day follow-up observation period.

If the current test series proves successful, the team plans to work on a lighter and more streamlined version of the WAK. Future tests will aim at developing a method of slow, steady, round-the-clock dialysis to mimic the working of a normal kidney. According to the team, this would not only be a more natural routine, but would also free patients from some diet restrictions.

The Wearable Artificial Kidney is discussed in the video below.

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