Real-Time Physiological Simulation and Modeling toward Dependable Patient Monitoring Systems

We present a novel approach to describe dependability measures for intelligent patient monitoring devices. The strategy is based on using a combination of methods from system theory and real-time physiological simulations. For the first time not only the technical device but also the patient is taken into consideration. Including the patient requires prediction of physiology which is achieved by a real-time physiological simulation in a continuous time domain, whereby one of the main ingredients is a temporal reasoning element. The quality of the reasoning is expressed by a dependability analysis strategy. Thereby, anomalies are expressed as differences between simulation and real world data. Deviations are detected for current and they are forecasted for future points in time and can express critical situations. By this method, patient specific differences in terms of physiological reactions are described, allowing early detection of critical states

Fault Propagation Analysis on the Transaction-Level Model of an Acquisition System with Bus Fallback Modes

The early fault analysis is mandatory for safety critical systems, which are required to operate safely even on the presence of faults. System design methodologies tackle the early design and verification of systems by allowing several abstraction for their models, but still offer only digital bit faults as fault models. Therefore we develop a signal fault model for the Transaction-Level Modeling. We extend the TLM generic payload by the signal characteristics: Voltage level, delay, slope time and glitches. In order to analyze and process these, a TLM bus model is created, with which signal faults can be detected and translated to data failures. Furthermore, inserting this bus in an acquisition system and implementing fallback modes for the bus operation, the propagation of the signal faults through the system can be assessed. Simulating this model using probability distributions for the different signal faults, 5516 faults have been generated. From these, 5143 have been recovered, 239 isolated and 134 turned into failures

Mathematical Analysis of Computer Generated Binary Fourier Transform Holograms

A rigorous mathematical treatment of a general binarization process for computer generated binary Fourier transform hologram is developed. Further a generalized error diffusion coefficient matrix is derived. In the view of these mathematical results we distinguish different binarization methods by the error diffusion process. Some binarization methods, their properties, and computational demands are investigated. Examples are presented

Three architectures for volume rendering

Volume rendering is a key technique in scientific visualization that lends itself to significant exploitable parallelism. The high computational demands of real-time volume rendering and continued technological advances in the area of VLSI give impetus to the development of special-purpose volume rendering architectures. This paper presents and characterizes three recently developed volume rendering engines which are based on the ray-casting method. A taxonomy of the algorithmic variants of ray-casting and details of each ray-casting architecture are discussed. The paper then compares the machine features and provides an outlook on future developments in the area of volume rendering hardware