In the last years peritoneal dialysis has established as one of the best solutions to treat end-stage renal disease patients. The possibility of performing the dialytic sessions at home, automatically and overnight has increased the spread of the therapy known as Automated Peritoneal Dialysis (APD). APD treatment is managed and controlled by the cycler. It consists of a device that actively regulates the motion of the dialysis fluid inward and outward the patient. Improvements in peritoneal dialysis are directly related to a better management of the therapy, and therefore on a continuous evolution of the pumping mechanism at its basis. This thesis focuses on the fluid dynamic characterization of two innovative prototypes of diaphragm pump for APD.