Entwicklung, Regelung und Validierung eines neuartigen Herzunterstützungssystems zur gezielten Lasteinstellung
- Development, control and validation of a novel ventricular assist device for targeted load adjustment
Salesch, Tobias Christopher; Abel, Dirk (Thesis advisor); Hein, Marc (Thesis advisor)
Aachen : RWTH Aachen University (2023)
Dissertation / PhD Thesis
Dissertation, Rheinisch-Westfälische Technische Hochschule Aachen, 2023
This thesis deals with developing, controlling, and validating a novel ventricular assist device. The iterative development process is described, starting with the components' design and finishing with the system's validation. The system's goal is, in addition to an adaptive relief of the heart, to specifically enable further improvements by integrating new degrees of freedom. On the one hand, the novel character refers to a conceptually innovative design that adds a second pump to the ventricular assist devices of the current state of the art. On the other hand, the control of conventional systems, which consists of only one pump, is cleverly extended by a virtual degree of freedom. These two fundamentally different approaches are evaluated separately and then compared. Various hardware and software components were added to the existing digital research platform to achieve these goals. In particular, a test bench adapted explicitly for ventricular assist devices was developed, which enables a hardware-based evaluation of the designed components. A methodological focus is formulating and executing optimization problems based on object-oriented modeling of the cardiovascular system. A physiologically valid simulation model is developed with a parameter optimization problem that forms the basis for designing suitable control strategies. The combination of cyclic parameter optimization with a subsequent optimal problem control enables the achievement of physiological control goals in the sense of a closed control loop. In addition to this model-based optimization approach, various model-free physiological controllers were designed and implemented for both approaches. The evaluation of all physiological controllers concerning control performance and stability is performed on the designed test bench. The prototypical validation of the systems is carried out in animal trials. In test series with varying control goals, it could be shown that the integration of further degrees of freedom works with both approaches and brings advantages compared to the current state of the art. The extension by a second pump additionally enables a fundamental decoupling of the control objectives.
- Chair and Institute of Automatic Control