Abstract: A method and apparatus for reconstructing an image of an object using a three dimensional (3D) computerized tomographic (CT) imager having a cone beam radiation source and detector arrangement for acquiring measurement data. The source and detector arrangement is operated at a plurality of source positions along a spiral scan path so as to acquire a corresponding plurality of sets of measurement data representative of radiation attenuation caused by the object. Image reconstruction processing information required for processing of the acquired measurement data in a Radon space partitioned by plurality of vertically oriented coaxial .phi.-planes for reconstructing the image, is pre-calculated and stored in a hitlist. The stored information is pre-calculated on less that all of the .phi.-planes, but due to a symmetry that is induced in the reconstruction processing, the stored information can be used for calculating Radon data for all of the .phi.-planes that partition the Radon space.

Abstract: A two-step 3D Radon inversion processor for processing Radon data on a set of vertically oriented co-axial .phi.-planes that partition Radon space, wherein each of the .phi.-planes is sampled during the processing so as to have its own independent local Radon origin. In accordance with further principles of the present invention, a 3D Radon data generator generates Radon data on a set of vertically oriented co-axial .phi.-planes that partition Radon space, wherein each of the .phi.-planes is sampled so as to have its own independent local Radon origin, and a two-step 3D Radon inversion processor independently processes each of the .phi.-planes. Any shift of the local Radon origins with respect to a global coordinate system is compensated for during the 3D Radon inversion processing. Compensation for the origin shift may be made during or after a first step of the Radon inversion processing.

Abstract: A method and apparatus for automatically locating a desired region of interest (ROI) in an original digital image having a plurality of pixel intensity values, comprising:(a) obtaining digital image intensity data representative of an original digital image;(b) sampling the digital image intensity data of the original digital image so as to define a reduced digital image representative of the original digital image;(c) forming an image intensity histogram using the reduced digital image;(d) determining a threshold image intensity value from the histogram as being representative of a minimum image intensity value of a desired ROI;(e) creating a mask image from the reduced digital image, the mask image having image pixels at grid coordinate positions corresponding to similarly positioned pixels in the original digital image, by setting all image pixels in a mask image grid to one of at least a maximum and a minimum intensity value, depending upon a comparison of the threshold intensity value to the image intens

Abstract: A scanning and data acquisition method and apparatus for three dimensional (3D) computerized tomography (CT) imaging of a region-of-interest (ROI) in an object, wherein image reconstruction processing is applied to a plurality of sets of cone beam projection data, each set being acquired on a detector at a corresponding plurality of scan path source positions. A first image reconstruction processing step comprises applying a mask to each set of the projection data to form masked data sets. The mask for each data set is formed by cone beam projections onto the plane of the detector of portions of the source scan path that are above and below the source position that acquired the data set being masked.

Abstract: A scanning and data acquisition technique for three dimensional (3D) computerized tomographic (CT) imaging of an object, wherein scanning at a plurality of positions along a source scanning trajectory causes an area detector to acquire cone beam projection data corresponding to a shadow of said object at each of scanning positions and Radon derivative data is calculated by processing line integral values from cone beam projection data. In order to improve the calculation efficiency of the Radon derivative calculation, calculation of the Radon derivative data uses a determination of the left and right boundaries of the shadow for each of the scanning positions, and calculates the Radon derivative data only using projection data from within the determined boundaries.

Abstract: Telemetry transmitting apparatus and a method are provided for reception and transmission of heart related electrical signals, such as electrocardiogram (EKG) and/or cardiac pacemaker signals, from a plurality of electrodes coupled to the body of a medical patient. A receiving facility of the apparatus receives a plurality of analog signals representing at least the EKG signals. An output signal representing the EKG signals is formed and transmitted, via a wireless coupling, to a telemetry receiver. An analog output port is provided on the telemetry transmitting apparatus. The analog output port is also coupled to the receiving facility. A plurality of output signals representing the EKG signals is provided to the analog output port of the telemetry transmitting apparatus. The analog output port may be coupled to buffers at the input terminals of the apparatus.

Abstract: A method and apparatus for reconstructing an image of an object using a three dimensional (3D) computerized tomographic (CT) imager having a cone beam radiation source and detector arrangement for acquiring measurement data. Before the acquisition of measurement data during an imaging operation of the apparatus, image reconstruction processing information dependant on the geometric parameters of the imager and required for processing of the acquired measurement data for developing contributions to the final reconstruction of the image, is pre-calculated and stored. During an imaging operation of the apparatus, the acquired measurement data is processed using the pre-calculated image reconstruction processing information for reconstructing the image.

Abstract: A data compression method and apparatus for processing a stream of original data samples to produce a compressed data stream that comprises both compressed and not-compressed data samples. The technique includes a data compression means for applying a data compression technique to said original data samples so as to develop a sequence of compressed original samples and not-compressed original samples, and providing the sequence of samples in a data portion of a transmission packet. A compression indicator means is also provided for developing a sequence of bits indicating which of the samples in the compressed data stream are representative of one of the compressed original samples and not-compressed original samples, and providing the sequence of bits in a map portion of the transmission packet. The map portion of the transmission packet is used for rapid identification and decompression of the compressed data.

Abstract: A method and apparatus for classifying an input as belonging to one of a plurality of predefined classes, comprises: (a) developing a plurality of feature values and forming a feature vector from the feature values which is representative of the input, (b) applying the feature vector to a knowledge-base comprising predictivity curves for each class of said plurality of classes, and developing a plurality of predictivity values for each feature, each predictivity value being indicative of a likelihood of the input belonging to a respective one of each of said classes based on the feature value; (c) combining the predictivity values developed for each of the features for each class to generate a total predictivity value for each class; and (d) generating a determination of class based upon the total predictivity values generated by the prior step.

Abstract: A scanning and data acquisition method and apparatus for three-dimensional computerized tomographic imaging of a region of interest (ROI) of an object which is smaller than the object itself and having upper and lower boundaries which are completely within a field of view of an imaging system comprises merely a continuation of the scan trajectory used for scanning the main portion of the ROI so as to extend past its upper and lower boundaries. In a preferred embodiment, the scan path of the present invention consists of a main spiral scan path comprising a plurality of spiral turns, or stages, for scanning between upper and lower boundaries of the ROI, and at least a portion of an extra single spiral turn of the scan path at each end thereof.

Abstract: A method and apparatus for displaying physiological signals acquired from a patient in a manner that allows for reliably associating with the physiological signals acquired from the patient user generated message information. The method comprises the steps of, receiving at a central station physiological signals acquired from a patient; and arranging a display portion of the central station to have at least one first display area dedicated for displaying said physiological signals, and at least one second display area, located adjacent said first display area, dedicated for displaying a user generated message related to the physiological signals displayed in said first area.

Abstract: A heartrate monitor of the invention includes a signal receiver adapted for being coupled to at least one sensor coupled to a medical patient, for providing an ECG signal and a pacemaker detection signal. A pacemaker activity checker, responsive to the pacemaker detection signal and the ECG signal provides first and second output signals, the first output signal indicating the occurrence of a QRS complex in the vicinity of the pacemaker detection signal, and the second output signal indicating the occurrence of an overshoot in the vicinity of the pacemaker detection signal. An overshoot validator, responsive to the ECG signals and the second output signal indicates the validity of the indicated overshoot. A QRS detector, responsive to the ECG signal, indicates the occurrence of a QRS complex in the ECG signal.

Abstract: A monitor system for acquiring medical data from a patient is distributed over at least two geographically separate patient monitoring areas and interconnected via a communication network. A portable monitor (102) coupled to a patient receives and processes patient data signals from a sensor coupled to the patient. At least two patient monitor docking stations (111) are provided, each one of which is selectively coupled to the portable monitor and connected for transmission of patient data received from the portable patient monitor to the communication network.

Abstract: In accordance with the principles of the present invention, image reconstruction errors which occur when using an area detector having a plurality of rows of detector elements defining a height for the detector that is smaller than the cone beam image, can be avoided by correlating an amount of orthogonal translation applied to line segments L extending across the detector towards top and bottom edges thereof that are used for calculating Radon derivative data, with the spacing between adjacent rows of the detector elements that are at the top and bottom edges of the detector. In a preferred embodiment the detector comprises a plurality of M rows of detector elements centered between the top and bottom edges of the detector, and an additional N rows of detector elements adjacent the M rows, at both of the top and bottom edges of the detector (where N may equal 1).

Abstract: A method and apparatus for reducing noise in an output signal produced from a plurality of input signals indicative of a repetitious phenomena exhibited by a signal source.

Abstract: Telemetry transmitting apparatus and a method are provided for reception and transmission of heart related electrical signals, such as electrocardiogram (EKG) and/or cardiac pacemaker signals, from a plurality of electrodes coupled to the body of a medical patient. A receiving facility of the apparatus receives a plurality of analog signals representing at least the EKG signals. An output signal representing the EKG signals is formed and transmitted, via a wireless coupling, to a telemetry receiver. An analog output port is provided on the telemetry transmitting apparatus. The analog output port is also coupled to the receiving facility. A plurality of output signals representing the EKG signals is provided to the analog output port of the telemetry transmitting apparatus. The analog output port may be coupled to buffers at the input terminals of the apparatus.

Abstract: In a patient monitoring system which includes a signal transmission path between that portion of the patient monitoring system which acquires the physiological signals and that portion of the system which processes and displays the acquired signals, a method and apparatus is provided for displaying to a user of the system a time delay that is associated with a delay of the display of the physiological signals.

Abstract: A digital subtraction angiography method useful for processing a mask and contrast series of two dimensional (2D) images acquired by rotational imaging of a selected volume of a body. The method reduces image artifacts caused by misregistration, and is unique in that for registration purposes it treats the acquired 2D images as a volume. The individual 2D images are stacked in a sequence so as to have the dimensions x, y and .theta.. A flexible volume registration is then performed to bring the mask and contrast volumes into a close match prior to subtraction.

Abstract: A monitor system for acquiring medical data from a plurality of sensors adapted for coupling to a patient located in a given patient monitoring area. The system comprises a portable monitor, a peripheral device, and a docking station. The portable monitor is adapted to be coupled to the plurality of sensors for receiving, processing and displaying patient data signals acquired from the plurality of sensors The peripheral device requires connection to the monitoring system, and comprises, i.e., a strip chart recorder. The docking station is located within the given patient monitoring area and includes at least first and second docking station platforms adapted for being selectively coupled to the portable monitor and the peripheral device respectively, for providing data transfer between the peripheral device and the portable monitor while the portable monitor acquires medical data from the patient.

Abstract: An apparatus for monitoring the respirations of a patient includes a device for generating a respiration signal having amplitude modulations representative of patient respirations, as well as respiration artifacts, and a processor coupled to the respiration signal generating device and responsive to the respiration signal for 1) detecting inflection points in the respiration signal; 2) determining if either one of a portion of the respiration signal which precedes or follows each detected inflection point has a slope which exceeds a predetermined slope threshold level which is indicative of a respiration artifact; and 3) developing breath indication information based upon the slope threshold determination.