Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
ANALYSIS OF THE PRESSURE FIELD IN ARTERIOVENOUS FISTULA
Submission Author:
Lucas Penha , RN
Co-Authors:
Lucas Penha, Willyam Brito de Almeida Santos, Jonhattan Ferreira Rangel, Sabrina Machado Santos, Allan Santos, Kleiber Lima de Bessa
Presenter: Lucas Penha
doi://10.26678/ABCM.COBEM2023.COB2023-0682
Abstract
Hemodialysis is the best treatment for patients with chronic renal failure. To perform this treatment it is necessary to design a vascular access (VA). One of the common complications in arteriovenous fistula (AVF) is steal syndrome, due to the detour of arterial blood to the AVF and not to the peripheral limbs of the patient’s. This study analyzed the pressure field and flow conditions in an arteriovenous fistula model (in vitro) subjected to the conditions of steal syndrome on a permanent experimental bench. For the completion of the work, an ideal AVF was modeled and manufactured with pressure acquisition points in the distal and proximal arterial regions, anastomosis, and venous region. Following this stage, the AVF with a 45° anastomosis angle (AA) was fabricated using 3D printing.For the experimental analysis pressure transducers were used MPX5050DP, ball valves 1⁄3″, flow sensor USN-HS41TA, diaphragm motor pump S-60-12, Arduino UNO/NANO e ESP 32 LoRa. The AVF was submitted to 2 flow configurations: configuration A, a flow with a maximum mean flow rate equal to 2163.26 ml/min in the proximal artery and zero flow rate in the distal artery, and configuration B, in which a flow rate of 70% of the maximum mean flow rate was applied in the proximal artery and 30% in the distal artery. In the experiments, for A, the pressure differential varied from 14,20 kPa at P1 (Pressure Point 1) at the entrance to the proximal artery to 1,00 kPa at P5 (Pressure Point 5) at the exit of the venous segment. For B, the pressure varied from 11,65 kPa at P1 to 1,20 kPa at P5. It can be inferred that the AA is the cause of most of the energy dissipated in the flow, as the sudden change in geometry at the anastomosis causes the flow to separate.
Keywords
Arteriovenous Fistula, pressure drop, Ischemic steal syndrome, Flow rate, Angle of Anastomose
