Design and validation of an implantable actuator for use in a novel dynamic arteriovenous shunt system

Abstract

Millions of people around the world rely on kidney dialysis to replace the essential function of their kidneys. In order to receive dialysis, adequate access to the circulation is needed. The golden standard, the Arteriovenous Fistula (AVF), hasn’t really changed since the 1940’s and comes with disappointing patency and reintervention rates. This is most likely due to increases in the flow pattern in the shunt and vein adjacent to the shunt. For a novel type of shunt that can regulate the blood flow, an implantable actuator needs to be developed and validated that can function as an interface and supply a force to the valve regulating the blood flow. In this study, an implantable actuator was developed using a methodological design approach that can deliver various output forces over an axial displacement using a magnetic coupling. It gives maximum control over the shunt by allowing control over the speed of the displacement and introduces multiple locking states. The actuator was then tested using various experimental tests. First the maximum force output was tested, then the reliability and durability were tested. Lastly, a goat cadaver study was performed to test the function of the device. From this study it was concluded that the actuator met all the design requirements and therefore provided an adequate proof-of-concept for the actuator as part of a dynamic arteriovenous shunt system. Next, the actuator should be implemented in the full shunt system and get connected to the valve using a suitable transmission system.