ReplioCardio – Grasping the Heart

Even when viewed with red-green glasses or 3D displays, virtual models displayed on a computer monitor provide a less than adequate spatial representation of complex 3-dimensional shapes such as, for instance, a diseased heart. For this reason, the RepliCardio working group is involved in replicating hearts (see link below), using as their basis digital image data from 1) pathological specimens and 2) living patients.

In Germany alone, 6,000 children are born each year with a congenital heart defect, the most common congenital disorder. Thanks to significant progress in heart surgery, today about 90 per cent of these children reach adulthood. Yet, following corrective surgery, only a very few patients have a healthy heart, while most need to have further operations performed in the course of their lives. In view of the enormous geometric and morphological diversity of congenital heart defects and the amount of scarring remaining from previous operations, surgeons are faced with special challenges. Up to know, in seeking to visualize the diseased organ, surgeons had to rely on knowledge obtained from pathological specimens and on specialized experience as well as two-dimensional or, more recently, 3-dimensional image data. Yet even using virtual, 3-dimensional reality, a precise comparison, particularly with respect to the size and exact position of anomalous structures, may hardly ever be satisfactorily achieved. For this reason, the example of automobile engineers was followed. Using virtual surface data sets, they print out prototypes of instrument panels, for example, so as to able to “grasp” their shape before manufacturing. With respect to diversity and precision, methods for producing models have gone through a dramatic development in recent years. As a result, the quality of the surface data set upon which the model is based is especially decisive for the outcome. With pathological heart specimens, a virtual surface data set is relatively easy to generate, since the heart contrasts very well with the surrounding air. The technology for the “Heidelberger Raytracer” was already developed by our department to serve this purpose in 1991.

A living heart muscle, on the other hand, does not stand out as well against surrounding tissue or the inner cavity, which is filled with blood, and moves continuously besides. Models of the human skeleton, for example to be used in oral, facial surgery or orthopedics , have been fashioned for years. Soft tissue organs, in contrast, represent an extraordinary challenge. Within special research area 414 “Computer and Sensor Supported Surgery”, our working group in subproject Q3 has developed software tools that allow segmentation of the pericardium with automatic interpolation or by using simplex meshes. In addition, algorithms have been programmed for the purpose of generating surface data sets. The first cast specimen of a living heart succeeded in 2005 and received the CaseReport-Posterpreis of the German Society of Pediatric Cardiology.

Further information

Project manager