CircAdapt Model

The CircAdapt model enables simulation of blood pressures, volumes, and flows in heart and circulation on a beat-to-beat basis. Initially, this model was designed for teaching purposes, showing the importance of the physical laws of mechanics and fluid dynamics in understanding cardiovascular physiology. While designing the model, the developers have paid serious attention to the maintenance of the following properties: 
  1. The model is easy to use; 
  2. The simulations are realistic; 
  3. The principles used are based on physics and physiology; 
  4. The number of parameters is limited; and 
  5. Modification to pathology is easy. 
Therefore, the model is composed of recognizable modules, such as heart chambers, valves, blood vessel tubes and peripheral microcirculations. In a first simulation, the whole model works, but mechanical load in the different cardiac and vascular tissues is unevenly distributed. Tissues are known to have long-term adaptive properties, forcing the tissues to adapt size and structure so that local mechanical load is normalized. The 
modules in the CircAdapt model can adapt their own geometry so that mechanical load in the constituting tissue becomes physiological. Thus, each module's geometry is self-generating, resulting in a substantial parameter reduction. Currently, simulations appear so realistic and the CircAdapt model structure is so flexible and versatile that CircAdapt is successfully used for fundamental research in the field of cardiovascular 
(patho)physiology. Inclusion of adaptation makes the model very promising in predicting long-term effects of pathology and clinical interventions. CircAdapt may therefore also be a valuable tool for clinical specialists. 

More detailed descriptions of the different CircAdapt modules are under construction and will be published on this website soon. 

CircAdapt Simulator

To extend the application range of the comprehensive CircAdapt model from research to education a project was launched to build a novel, interactive simulation environment that can be used by medical students with the aim to improve their understanding of cardiovascular hemodynamics and related physiology. This resulted in the CircAdapt Simulator, which is nothing more than an interactive user-friendly shell around the CircAdapt model. Without much foreknowledge, a novice user can intuitively simulate complex pathophysiological situations by manipulating for instance diameter and leakage of heart valves, contractility and stiffness of cardiac walls, stiffness of arteries, and by the creation of shunts. A wide selection of hemodynamic signals (blood flow velocity, cardiac cavity volume or blood pressure) can be displayed as required to show resulting effects. Because of its versatility, the CircAdapt Simulator is an ideal tool for teaching cardiovascular physiology 
and pathophysiology over a wide range of complexities. Besides being an excellent tool for medical students, it is also suitable for analyzing more complex situations to train residents in different clinical disciplines (e.g., cardiology, neonatology and intensive care medicine). Presently, the CircAdapt Simulator is successfully integrated into the first, second and third year of the Maastricht University medical school. From current 
experience it is thought that for best didactic results, the CircAdapt Simulator should be embedded in a well designed practical setup in which students are challenged, step by step, to predict the outcome of an intervention, and use the tool as a check of their predictive thoughts.
A user manual and two case-based tutorials ("normal cardiac pump function" and "mitral insufficiency") are available for free download on the documentation page.