Characterizing protein interactions employing a genome-wide siRNA cellular phenotyping screen.

Characterizing the activating and inhibiting effect of protein-protein interactions (PPI) is fundamental to gain insight into the complex signaling system of a human cell. A plethora of methods has been suggested to infer PPI from data on a large scale, but none of them is able to characterize the effect of this interaction. Here, we present a novel computational development that employs mitotic phenotypes of a genome-wide RNAi knockdown screen and enables identifying the activating and inhibiting effects of PPIs.

An aneurysm clipping training module for the neurosurgical training simulator NeuroSim.

Having introduced NeuroSim, the prototype of a neurosurgical training simulator at MMVR18, we present our first medical training module. NeuroSim is based on virtual reality and uses real-time algorithms for simulating tissue. It provides a native interface by using a real surgical microscope and original instruments.

NeuroSim--the prototype of a neurosurgical training simulator.

We present NeuroSim, the prototype of a training simulator for open surgical interventions on the human brain. The simulator is based on virtual reality and uses real-time simulation algorithms to interact with models generated from MRT- or CT-datasets. NeuroSim provides a native interface by using a real surgical microscope and original instruments tracked by a combination of inertial measurement units and optical tracking.

EYESi ophthalmoscope - a simulator for indirect ophthalmoscopic examinations.

We present a training simulator for indirect ophthalmoscopy. An optical tracking system is used to reconstruct the position of a lens mockup and a model of the patient's face. Refraction and illumination are computed in real-time and displayed on a head-mounted display using augmented reality.

Development of a guiding endoscopy simulator.

Endoscopy simulators get more and more common for the training of physicians. It is important to make simulation as realistic as possible by providing optical, acoustical and haptical feedback. The haptic display of our simulator EndoSim allows applying active forces to all degrees of freedom and moving to defined positions.

Real-time Marker-based Tracking of a Non-rigid Object.

Real-time tracking of non-rigid objects for use in interfaces of VR-simulators is presented. Markers are attached to the objects and observed by several cameras with integrated image-processing hardware which extracts relevant marker data (centroid, area & color) in real-time. Data from the different cameras is then matched in the host PC to reconstruct the 3D positions.

Limits for the central production of Theta+ and Xi(--)pentaquarks in 920-GeV pA collisions.

We have searched for Theta+(1540) and Xi(--)(1862) pentaquark candidates in proton-induced reactions on C, Ti, and W targets at midrapidity and square root of s = 41.6 GeV. In 2 x 10(8) inelastic events we find no evidence for narrow (sigma approximately 5 MeV) signals in the Theta+ --> pK0(S) and Xi(--) --> Xi- pi- channels; our 95% C.

Computer-generated stratified diffractive optical elements.

We present what is to our knowledge a new type of diffractive optical element (DOE), the computer-generated stratified diffractive optical element (SDOE), a hybridization of thin computer-generated DOEs and volume holograms. A model and several algorithms for calculating computer-generated SDOEs are given. Simulations and experimental results are presented that exhibit the properties of computer-generated SDOEs: the strong angular and wavelength selectivity of SDOEs makes it possible to store multiple pages in a computer-generated SDOE, which can be read out separately (multiplexing).

[Cathi-training on virtual patients for catheter interventions].

In this paper we present a trainings system for catheter interventions, especially PCTAs also called ballon dilatation. Despite the large number of such interventions the education of the cardiologist is still based on learning on the patient. This means risk to the patient and additional cost.

Operation planning of correction osteotomies in 3D.

This paper discusses an operation planning system for correction osteotomies. It is based on 3D data obtained from CT/MR of the bone and it allows to perform a 3D planning. The physician can individually determine anatomical landmarks for measuring geometric parameters of the bone like length, angle and torsion angle.

A divide and conquer approach to fast loop modeling.

We describe a fast ab initio method for modeling local segments in protein structures. The algorithm is based on a divide and conquer approach and uses a database of precalculated look-up tables, which represent a large set of possible conformations for loop segments of variable length. The target loop is recursively decomposed until the resulting conformations are small enough to be compiled analytically.

Ultrasound, a new tool for surface matching in computer-navigated surgery.

Objective: The object of this study was to investigate the feasibility of generating a bone surface from data provided by an ultrasound examination and to match this surface with the previous computed tomography (CT) scan.

Methods: From a CT data set of a training model of the pelvis, a three-dimensional surface was extracted by global thresholding-based segmentation. The same model was placed in a water basin, and ultrasound images were taken with a guided ultrasound transducer.

[Virtual reality in ophthalmological education].

We present a computer-based medical training workstation for the simulation of intraocular eye surgery. The surgeon manipulates two original instruments inside a mechanical model of the eye. The instrument positions are tracked by CCD cameras and monitored by a PC which renders the scenery using a computer-graphic model of the eye and the instruments.

Computer simulation of osteotomy correction.

This paper describes a novel approach to correct osteotomy deformities of long bones using virtual reality and image processing techniques on personal computers. The discussed method allows to simulate osteotomy corrections by implementing a single cut and a rearrangement of the dissected bone parts. It allows the surgeon to directly control the pre-operative situation and the post-operative result of the simulation by comparing bone-length, angles, and torsion of the bone.

Computer assisted treatment of pelvis fractures.

The presented approach is the realization of a minimal invasive treatment of pelvis fractures using the computer aided surgery (CAS). Main problem of tracking of major bone fragments after reposition is solved by implementing of 3D ultrasound to obtain intraoperative bone surfaces. Preoperative and intraoperative data sets are matched.

Real-time direct volume rendering in functional magnetic resonance imaging.

Direct volume rendering is a visualization method that allows display of all information hidden in three-dimensional data sets of, for example, computed tomography or magnetic resonance imaging (MRI). In contrast to commonly used surface rendering methods, these algorithms need no preprocessing but suffer from a high computational complexity. A real-time rendering system, VIRIM (Vitec: Visualization Technology GmbH, Mannheim, Germany), cuts down rendering times of minutes on normal workstations to an interactive rate of 1 second or less.

Gradual and random binarization of gray-scale holograms.

A new method called gradual and random binarization to binarize gray-scale holograms, based on an iterative algorithm, is proposed. The binarization process is performed gradually, and the pixels to be binarized are chosen randomly. Errors caused by this operation are spatially diffused.

A hybrid neural and statistical classifier system for histopathologic grading of prostatic lesions.

Neural network and statistical classification methods were applied to derive an objective grading for moderately and poorly differentiated lesions of the prostate, based on characteristics of the nuclear placement patterns. A partly trained multilayer neural network was used as a feature extractor. A hybrid classifier system using a quadratic Bayesian classifier applied to these features allowed grade assignment consensus with visual diagnosis in 96% of fields from a training set of 500 fields and in 77% of 130 fields of a test set.

Multiprocessor and memory architecture of the neurocomputer SYNAPSE-1.

A general purpose neurocomputer, SYNAPSE-1, which exhibits a multiprocessor and memory architecture is presented. It offers wide flexibility with respect to neural algorithms and a speed-up factor of several orders of magnitude--including learning. The computational power is provided by a 2-dimensional systolic array of neural signal processors.

Radiographic pulmonary changes of gastro-oesophageal reflux disease in elderly patients.

The aim of this study was to investigate the association of gastro-oesophageal reflux disease (GORD) with radiographic pulmonary changes. One hundred and thirty-seven patients aged over 60 years referred for endoscopy for abdominal symptoms were included in the study. In patients with any suspicion of GORD (n = 95), 24-hour oesophageal pH monitoring was carried out.

Real-time multiprocessing of slit scan chromosome profiles.

The multiprocessor NERV and its application to slit scan flow cytometry is described. Up to 320 processors and 640 MBytes of RAM may be used in one VME crate, providing a computing power of less than or equal to 1300 MIPS. The multiprocessor is controlled by a host computer that provides a friendly user interface and comfortable program development tools.

Biological dosimetry by chromosome aberration scoring with parallel image processing with the Heidelberg POLYP Polyprocessor system.

Chromosome aberrations in human peripheral blood are recognized parameters of cellular damage and are used as indicators of exposure to ionizing radiation. In order to reach the low dose range, up to 10,000 metaphase cells each consisting of 46 chromosomes have to be analysed for each radiation exposed person. In order to perform this task within reasonable time limits the application of the Heidelberg POLYP Polyprocessor is considered.