Abstract: A location system comprises a plurality of transponders whose locations are detectable by a base system. The base system interrogates (51-55) the transponders one at a time in accordance with a schedule of consecutive time slots. In response to a priority request received (53) from one of the transponders, the base system interrupts the schedule and interrogates substantially immediately (56, 57, 55) the signaling transponder so as to determine its location with minimal latency.

Abstract: A location system comprises a plurality of transponders whose locations are detectable by a base system. The base system interrogates (51-55) the transponders one at a time in accordance with a schedule of consecutive time slots. In response to a priority request received (53) from one of the transponders, the base system interrupts the schedule and interrogates substantially immediately (56, 57, 55) the signaling transponder so as to determine its location with minimal latency.

Abstract: A system for monitoring the presence of persons within a zone, the system comprising: one or more remotely detectable markers, each capable of being carried by a person; a first sensor arrangement capable of identifying the presence of the body of at least one person within the zone; a second sensor arrangement capable of identifying the presence of at least one marker within the zone; and a processing arrangement responsive to the first sensor arrangement and the second sensor arrangement to generate an alarm signal if the first sensor arrangement identifies the presence of a body without the second sensor arrangement identifying a marker corresponding in a first predetermined manner to that body.

Abstract: A location system comprises a plurality of transponders whose locations are detectable by a base system. The base system interrogates (51-55) the transponders one at a time in accordance with a schedule of consecutive time slots. In response to a priority request received (53) from one of the transponders, the base system interrupts the schedule and interrogates substantially immediately (56, 57, 55) the signaling transponder so as to determine its location with minimal latency.

Abstract: A location system comprises a plurality of transponders whose locations are detectable by a base system. The base system interrogates (51-55) the transponders one at a time in accordance with a schedule of consecutive time slots. In response to a priority request received (53) from one of the transponders, the base system interrupts the schedule and interrogates substantially immediately (56,57,55) the signalling transponder so as to determine its location with minimal latency.

Abstract: A technique is provided for providing total flexibility of control of any desired operation within an environment where personnel work, such as an office suite. The location of transponders is determined by a location system. A user arbitrarily selects a convenient region for controlling an operation and the location system registers this in a memory. The location system then determines the position of each transducer and, when a transducer is within one of the selected regions, the location system responds by controlling the operation. For example, a region may be selected entirely arbitrarily so as to control room lighting.

Abstract: A technique is provided for providing total flexibility of control of any desired operation within an environment where personnel work, such as an office suite. The location of transponders is determined by a location system. A user arbitrarily selects a convenient region for controlling an operation and the location system registers this in a memory. The location system then determines the position of each transducer and, when a transducer is within one of the selected regions, the location system responds by controlling the operation. For example, a region may be selected entirely arbitrarily so as to control room lighting.

Abstract: A technique is provided for providing total flexibility of control of any desired operation within an environment where personnel work, such as an office suite. The location of transponders is determined by a location system. A user arbitrarily selects a convenient region for controlling an operation and the location system registers this in a memory. The location system then determines the position of each transducer and, when a transducer is within one of the selected regions, the location system responds by controlling the operation. For example, a region may be selected entirely arbitrarily so as to control room lighting.

Abstract: A technique is provided for providing total flexibility of control of any desired operation within an environment where personnel work, such as an office suite. The location of transponders is determined by a location system. A user arbitrarily selects a convenient region for controlling an operation and the location system registers this in a memory. The location system then determines the position of each transducer and, when a transducer is within one of the selected regions, the location system responds by controlling the operation. For example, a region may be selected entirely arbitrarily so as to control room lighting.

Abstract: A reference image R is selected and a region of interest (ROI) is interactively selected encompassing a desired structure from a sequence of images of a moving structure. This ROI is cross-correlated with other real-time images by multiplication in the Fourier frequency domain, to determine if the desired structure is present in the image. If the structure is present, this image may be averaged with other images in which the structure is present to produce higher resolution adaptively averaged images. This invention is particularly useful in imaging coronary vessels. In an alternative embodiment, the offset of the desired structure may be calculated in a series of images. The images may then be sorted by this offset, and played back in that order to provide a "movie-like" display of the desired structure moving with the periodic motion.

Abstract: A cardiac segmentation system acquires a series of images acquires as slices through a volume, and as images at different time periods throughout a cardiac cycle. It displays an image to an operator which interactively selects a region of interest (ROI) of the image to be segmented, such as the left ventricle. A seed point is also selected within the ROI and the structure desired to be segmented. The image is then thresholded by a masking device classifying points within the ROI as above the threshold, or not above the threshold. A 3D connectivity device identifies points within the ROI having the same classification as an expanded seed point which are also contiguous with the seed point as the segmented structure. The segmented structure is expanded and a histogram is constructed. A new threshold is selected which separates modes of the histogram, and used to carry out a revised, final, segmentation of the current image. The centroid of the current image is used as a seed point in segmenting adjacent images.

Abstract: The present invention determines the epicardial boundary, being a closed curve dividing the myocardium from the tissue and blood surrounding the left ventricle. A mean and standard deviation is determined for pixels of a medical image of the subject's myocardial tissue. These are used to define a "goodness function" over the image which is positive for pixels statistically likely to be myocardial tissue, and negative for other pixels. An initial curve for modeling the epicardium in radial coordinates starts with a curve of inner myocardial boundary obtained my conventional imaging techniques. This curve is then iteratively updated to maximize the total "goodness function" of the region encompassed.