Rainer Schubert

A new representation of knowledge concerning human anatomy and function

By integrating concepts of computer graphics and artificial intelligence, novel ways of representing medical knowledge become possible. They allow unprecedented possibilities ranging from three-dimensional interactive atlases to systems for surgery rehearsal

A volume-based anatomical atlas

A volume model data structure for constructing 3-D anatomical atlases is discussed. The volume model provides the look and feel of an actual dissection by visualizing both surface and volume properties of the anatomy and is flexible, letting users easily incorporate extensions both on the level of the spatial primitives and the relational descriptions. The procedures for filling the data structure, and the visualization, composition, interrogation, and simulation tools used to explore the model are described. The development of a 3-D atlas of the human head to test the frameworks performance is also described.<<ETX>>

A computerized three-dimensional atlas of the human skull and brain.

PURPOSEnTo develop an anatomic atlas of the human head based on a volume model derived from MR and CT.nnnMETHODSnEvery voxel of this model was labeled by a neuroanatomist concerning its membership to a structural and/or functional region. A computer program was written that, instead of displaying precomputed images, allows the user to choose and compose arbitrary views.nnnRESULTSnThe user can subtract parts and ask for annotations just by using the mouse. Conversely, one can compose images by choosing objects from the list of anatomical constituents which is displayed on the screen. A set of dissection tools allows a look and feel that comes near to a true dissection. Operations that are not possible in a real dissection, such as reassembly or filling cavities, can be performed.nnnCONCLUSIONnThe authors have developed a computerized model that can be used for anatomy teaching and also as a reference for radiologists or surgeons. To replace classical atlases, the spatial resolution must be improved and speed must approach real time. Functional imaging data (position emission tomography and single photon emission CT) can be added to the system. The system is mobile and can be situated in classrooms, operating rooms, reading rooms, and libraries.

A 'virtual body' model for surgical education and rehearsal

A general digital model of human anatomy is very helpful both in supporting the process of anatomical segmentation and as a reference system for simulating surgical situations or even rehearsal of interventions. This article describes the data structure and implementation of such a model. Neither superhero nor crash-test dummy, Voxel-Man is an attempt to combine in a single framework a detailed spatial model enabling realistic visualization with a symbolic model of the human body. We show that although a general model does not correspond in detail to an individual patient, it does provide a variety of novel features for surgical education and training.

Exploring the Visible Human using the VOXEL-MAN framework

In principle the Visible Human data sets are an ideal basis for building electronic atlases. While it is easy to construct such atlases by just offering the possibility of browsing through the 2D slices, constructing realistic 3D models is a huge project. As one rather easy way to establish 3D use, we have registered the Visible Human data to the already existing 3D atlas VOXEL-MAN/brain. This procedure enables one to lookup anatomical detail in an atlas based on radiological images. Concerning the segmentation problem, which is the prerequisite for a real 3D atlas, we have developed an interactive classification method that delivers realistic perspective views of the Visible Human. As these volume based methods require high-end workstations, we finally have developed a multimedia program that runs on standard PCs and uses Quicktime VR movies.

The muscular compliance of the auditory tube: a model-based survey.

Objectives The role of the paratubal muscles, especially the medial pterygoid muscle, still is unclear. The aim of this study was to define the function of the medial pterygoid muscle concerning the muscular compliance of the auditory tube.

Spatial Knowledge Representation for Visualization of Human Anatomy and Function

Computerized presentation of knowledge about human gross anatomy and function is presently being developed along two major tracks. Computer graphics on one hand provides more and more powerful tools for volume visualization. Knowledge engineering on the other hand provides more and more sophisticated data structures, while it does not care much for proper visualization of such knowledge. This paper presents a new approach of representing medical knowledge with a volume based data structure. This method has major advantages for true three-dimensional visualization of anatomical and functional knowledge, as well as for presenting knowledge of different domains simultaneously. The basic ideas and a pilot implementation for the human skull and brain are presented. Remaining problems and possibilities for future extensions and improvements are discussed.

A mathematical analysis of theories of parthood

This paper presents a mathematical analysis of different formal ontological theories of parthood (mereologies). We summarize variants of the theory of General Extensional Mereology (GEM) and compare them with their abstract mathematical counterpart, set theory. In particular, we prove by set theoretical means that there exists a model of GEM where arbitrary summation of entities is not possible. Further, we use Stones duality theory for Boolean algebras to classify models of the different mereologies.

A New Method for Practicing Exploration, Dissection, and Simulation with a Complete Computerized Three-Dimensional Model of the Brain and Skull

In current practice, anatomical atlases are based on a collection of planar images presented in a book or, recently, stored on digital media. We present a new kind of interactive true three-dimensional (3D) anatomical atlases based on a volume model derived from MRI and CT. The model has a two-layer structure. The lower level is a volume model with a set of semantic attributes connected to each voxel. The semantic attributes are assigned by an anatomist using a volume editor. THe upper level represents a set of relations between these attributes. Interactive visualization tools such as multiple surface display, preparation of transparent material and cutting are provided. It is shown that the combination of this model with advanced tools for volume visualization provides the look and feel of real dissection. The system therefore represents a bridge between real dissection of a cadaver and textbooks and classical atlases of anatomy. First tests have shown that the atlas system may be used successfully for teaching anatomy, but also as a reference for radiologists or surgeons. The powerful underlying data structure potentially includes all classical visual teaching aids. As a replacement of classical atlases, however, spatial resolution has still to be improved.

Applications and Perspectives in Anatomical 3-Dimensional Modelling of the Visible Human with VOXEL-MAN

Up to now computerized interactive 3-dimensional (3D) atlases of human anatomy have been based on radiological data or artificial geometric models as spatial descriptions of morphological structures. Besides the obvious advantages of this data (e.g. already in digital format, geometrical correctness) the lack of high resolution anatomical slices of larger regions of the human body has prevented the use of more realistic anatomical data so far. Now, the Visible Human Project offers high quality anatomical slices of complete cadavers. Therefore, on the one hand, new opportunities for realistic virtual 3D models of anatomy are open. On the other hand, just the major advantages of the visible human data (e.g. realistic colors and textures, high resolution) result in new demands on the image processing and visualization techniques. This paper describes experience, solutions and results with a volume-based approach for building realistic anatomical 3D models.