The Design and Validation of a Monitoring System for the Dynamic Arteriovenous System

Abstract

Background: Kidney failure, also called end-stage renal disease, means the kidney has lost its function to remove waste from the blood. Patients with kidney failure usually need hemodialysis, which uses a machine to replace the function of a healthy kidney, to keep them alive and prolong their lives. In order to begin hemodialysis, it is crucial to prepare vascular access, which is a location in your body from which blood can be drawn and then returned at a high rate. People have found that the traditional ways of achieving vascular access will lead to a series of complications. So the newly designed Dynamic Arteriovenous system (DAS), which can control the opening and closing of the arteriovenous graft, was designed to solve the problem. Since the DAS is implanted under the skin of the human arm, it is hard for the operator to observe the status of the graft, so a monitoring system that can detect the graft status is needed.Objective:The goal of the research is to deisgn and evaluate a monitoring system for detecting the graft status of the DAS.Method: To solve the research problem, four sub-questions are proposed and solved to achieve possible concepts for the design. A Harris profile with grading criteria is set up to compare and determine the final concept to be developed. After building a test set-up for the final design, the design's effective range, accuracy, size, mass, usability, and detection success rate are evaluated. Results: The final design of the monitoring system consists of three sensors outside the body and two magnets in the DAS. The three sensors react to the position change of the magnets in the DAS and determine the relative position of the DAS under the skin and the status of the graft with the help of a User Interaction Interface. Through in-vitro tests, it is evaluated that the design meets most of the requirements and can be further developed if proper components are chosen and in-vivo tests are done. Conclusion: A relatively complete concept of the monitoring system and the corresponding User Interaction Interface are designed. Through a series of tests, it is believed to have the potential to be further developed and be useful to the DAS. In-vivo tests must be done to evaluate the system's biocompatibility before the clinical appliance.