Peristaltic Roller Pump: Parametric Optimization for Hemolysis Control

Abstract This work aims to analyze the various types of peristaltic pumps by studying, in particular, the use of the peristaltic roller pump to highlight its critical issues and propose new effective and innovative solutions. One possible application of this device is in hemodialysis, which is a physical therapy substitution of kidney function that allows, in almost all cases, recovery and maintenance of the main biological functions while remaining the uremic condition. As for the extracorporeal one, the equipment used to purify the blood from toxic substances that are no longer normally eliminated by kidney filtration is divided mainly into two types: rotary peristaltic pump and a linear peristaltic pump. Having to work with a very particular fluid such as blood and in direct contact with the patient, they need to be extremely accurate and must ensure a constant and continuous functioning. The rotary peristaltic pump is the most widely used for hemodialysis and having been extensively studied in literature it has since found extensive solutions in the application field. As is well known, peristaltic pump refers to a device that exploits the principle of peristalsis to function, i.e. the transit of a bottleneck on a tube, in this case, the catheter, to push the fluid contained outwards. In particular, a roundabout peristaltic pump consists of a rotating structure consisting of two or more rollers that in turn revolve around their axis. With their displacement, the rollers clog adjacent catheter sections at a time so that after the first roller has passed the tube returns to its initial size creating the vacuum and then sucking the fluid. In this way, the liquid is pushed from the tube towards the patient. The motion of all these components is powered by an electric motor connected directly to the main rotating structure. The pumping of fluids through hoses using the propagation of a peristaltic wave has been the subject of design and scientific studies for more than 4 decades. This is easily justifiable since the phenomenon of peristalsis is known to be an important responsible mechanism of fluid transport in many biological organs. The goal is (starting on studies on the blood, a variable density fluid) to analyze in detail the peristaltic roller pump and propose its parametric optimization, aimed at determining the critical speed, beyond which the machine damages any kind of fluid that needs special treatment (blood, food, special gel, medical ointments and so on).