Artificial kidneys consists of a number of tubes with semi-permeable lining (selective permeable membrane). These tubes are suspended in a tank filled with dialysing fluid. The dialysing fluid has the same osmotic pressure as blood. This fluid does not contain nitrogenous wastes.
Working: The blood of the patient is passed through dialysing tubes. As blood passes through tubes, the waste products (e.g., urea) from the blood pass into dialysing fluid by diffusion. The purified blood is pumped back into the patient artificial kidney does filtration but no reabsorption, like kidney.
Fig. Dialysis
