Abstract: A method of determining the quality of contact between a remotely navigated medical device and a cyclically moving anatomical structure includes measuring movement of the device, and processing the measured movement of the device to determine the contact between the device and the moving anatomical structure.

Abstract: A method of determining the quality of contact between a remotely navigated medical device and a cyclically moving anatomical structure includes measuring movement of the device, and processing the measured movement of the device to determine the contact between the device and the moving anatomical structure.

Abstract: A method renders a volume data set as an image in a volume rendering system. The volume data set includes a plurality of voxels stored in a memory. The volume rendering system includes a plurality of parallel processing pipelines. The image includes a plurality of pixels stored in the memory. A set of rays are cast through the volume data set. The volume data set is partitioned into a plurality of sections aligned with the sets of rays. Voxels along each ray of each set are sequentially interpolated voxels in only one of the plurality of pipelines to generate samples only as long as the samples contribute to the image.

Abstract: A method corrects opacity values of samples in a rendering pipeline. The method partitions a range of uncorrected alpha values into a plurality of segments in a low to high order. Corrected alpha values for uncorrected alpha values in the highest segment are determined by direct table look-up. Corrected alpha values for uncorrected alpha values in all but the highest segment are determined by linear interpolation.

Abstract: A method generates a histogram of a volume data set in a rendering pipeline. The volume data set includes a plurality of samples stored in a memory. Each sample is partitioned in parallel into a plurality of field according to a plurality of format registers, there is one format register for each field. Entries of a plurality of tables are indexed in parallel with the plurality of fields, there is one entry indexed in each table by each field. The indexed entries are incremented to accumulate a histogram of the fields of the samples of the volume data set.

Abstract: A method maps samples in a rendering pipelines. The samples are stored in a sample memory. Each sample has a plurality of fields. A descriptor is stored for each field in a field format register. Each sample is read from the memory into a mapping unit. The fields are extracted from each sample according to the corresponding descriptor, and forwarded in parallel to the rendering pipeline.

Abstract: A volume rendering pipeline includes a plurality of processing stages such as a gradient estimation stage, an interpolation stage, a classification stage, an illumination stage, and a compositing stage. The stages are connected to each other by multiplexers. A first multiplexer connects an output of a first stage to an input of a second stage. A second multiplexer connects an output of the second stage to an input of the first stage. A third multiplexer has inputs connected to the output of the first stage and the output of the second stage, the first, second, and third multiplexers are responsive to a select signal to configure the stages of the rendering pipeline for processing the volume data set.

Abstract: A method modulates samples in a volume rendering pipeline by storing modulation values as entries in a table. Also stored are a grain and a base for the entries of the table to specify an index range. A magnitude of a gradient vector of a sample is determined. The table is indexed using the magnitude to determine two modulation values corresponding to the magnitude. The two modulation values are interpolated using the grain and the base to determine a modulation factor to modulate the sample with a linear function.

Abstract: Apparatus for determining the position of a probe in a sensing volume includes a plurality of magnetic field generating sources for generating different magnetic fields in the sensing volume, where the sources have a planar configuration and are positioned so that they at least partially overlap one another in horizontal extent and so that the sensing volume extends outwardly from the sources. The probe is provided with sensors which detect magnetic field components of fields generated by the sources. The position of the probe can be determined from the detected magnetic components. Methods for determining the probe position are also included.