Session P85.5

A New Fuzzy Controlled ECSS-System: First Results of an In-Vitro Investigation

U Schreiber*, S Eichhorn, A Mendoza, B Baumgartner, R Bauernschmitt,
R Lange, A Knoll, M Krane

German Heart Center
Munich, Germany

Extracorporeal circulation (ECC) systems are routinely used during different procedures in cardiac surgery. The ECC provides adequate oxygenation and perfusion during cardiac arrest. For emergency situations a novel self-priming extracorporeal circulatory support system (Lifebridge B2T) was developed to ensure organ perfusion on site and during transportation to a clinic. The focus of this research is the development of an adaptive and robust control system that regulates perfusion based on online data that reflects the current hemodynamic situation of the patient. First results of an in-vitro investigation with a hydraulic blood circuit model are presented. The Lifebridge B2T, was augmented with a simple fuzzy control unit, that regulates the pump speed of the system based on the mean pressure (MP) of the hydraulic blood circuit model. The model consists of a Resistance-Compliance-Resistance (RCR) device representing the human blood circuit. To detect the MP a 1 french millar tip was introduced. The pressure sensor was placed approximately 20 cm beyond the tip of the canula for an interference-free MP signal. Four different scenarios were tested varying the pressure configuration of the model. The goal of the new fuzzy controller of the ECC-System was to regulate the MP to a value of 70 mmHg by decreasing or increasing the pump speed. First results of an in-vitro investigation using a hydraulic blood circuit model with the new ECSS Lifebridge B2T are presented. Using the Resistance-Compliance-Resistance circulation model we were able to regulate the system under perfusion to achieve the desired MP in all scenarios. In all of the four tested cases the fuzzy controlled system performed a regulation of the MP to 70 mmHG by up- or down-regulation of the pump speed in less then 10 seconds. A Resistance-Compliance-Resistance (RCR) model is a powerful tool to simulate different hemodynamic situations. The fuzzy controller has been successfully applied to a variety of scenarios, and seems to be effective in the control of ECC systems. Further experiments with the circulation model together with animal trials have to be performed to check and improve the fuzzy controller.

(Abstract Control Number: 233)