Abstract: A system is disclosed for monitoring the position of a medical instrument with respect to a patient's body and for displaying at least one of a plurality of prerecorded images of said body responsive to the position of said medical instrument. In one embodiment the system includes a reference unit secured from movement with respect to the patient's body such that said reference unit is substantially immobile with respect to a target operation site. The system also includes a remote unit for attachment to the medical instrument. A field generator may be associated with one of the units for generating a position characteristic field in an area including the target operation site. One or more field sensors may be associated with either of the units responsive to the presence of the position characteristic field for producing one or more sensor output signals representative of said sensed field.

Abstract: A system for automated x-ray system parameter evaluation is provided. A physical model or template is created and stored in the system, one for each desired phantom. The automated system imports a grayscale x-ray image and then processes the image to determine image components. First, a histogram of the image is created, then a threshold in the histogram is determined and the imported image is binarized with respect to the threshold. Next, connected component analysis is used to determine image components. If the components do not match, then the image is rejected. The system next locates landmarks in the imported image corresponding to expected physical structures. The landmarks include a perimeter ring, vertical and horizontal line segments, and fiducials. The system uses the landmarks to predict Regions of Interest (ROIs) where measurement of the x-ray system parameters takes place. Finally, the x-ray system parameters are measured in the identified ROIs.

Abstract: A computer site includes a data generating source. In one implementation, the source includes a device that can be manipulated by a patient to sense some function or condition of the patient. One example is a heart monitor that a patient can hold against his or her chest. The device outputs an audible signal responsive to the function or condition, such as the beating of the heart. A computer that can be operated by the patient or other initial user at the site runs a program that processes an electric signal generated in response to the audible signal as received through a microphone connected to the computer. The program is downloaded or otherwise accessed through a computer communication network, such as the Internet. The computer sends resulting data signals over the computer communication network.

Abstract: A system is disclosed for monitoring the position of a medical instrument with respect to a patient's body and for displaying at least one of a plurality of prerecorded images of said body responsive to the position of said medical instrument. In one embodiment the system includes a reference unit secured from movement with respect to the patient's body such that said reference unit is substantially immobile with respect to a target operation site. The system also includes a remote unit for attachment to the medical instrument. A field generator may be associated with one of the units for generating a position characteristic field in an area including the target operation site. One or more field sensors may be associated with either of the units responsive to the presence of the position characteristic field for producing one or more sensor output signals representative of said sensed field.

Abstract: A scanning electron beam computed tomographic system is provided with a sub-collimation system that passes X-rays emitted by a beam spot formed by an electron beam that is scanned across an X-ray emitting target, which X-rays would not otherwise reach an object under X-ray examination with the system. The sub-collimation system includes phantom-like objects that cause X-rays to be blocked, or passed, through to X-ray detectors depending primarily upon the beam spot position and, secondarily, on the beam-spot shape. Detector output signals may be used in real-time to control at least one characteristic of the electron beam-spot in a closed-loop correction system.

Abstract: An ultrasound system and method for calculation and display of tissue deformation parameters are disclosed. Tissue velocity may be estimated by filtering a received ultrasound signal at three center frequencies related to the second harmonic of the ultrasound signal, estimating a reference tissue velocity from the two signals filtered at the outside center frequencies and using the reference tissue velocity to choose a tissue velocity from tissue velocities estimated using the middle center frequency. Estimation of strain rate in any direction, not necessarily along the ultrasound beam, is disclosed. Quantitative tissue deformation parameters may be presented as functions of time and/or spatial position for applications such as stress echo. For example, strain rate or strain values for three different stress levels may be plotted together with respect to time over a cardiac cycle. Parameters derived from strain rate or strain velocity may be plotted with respect to various stress levels.

Abstract: An ultrasound system is disclosed for imaging structure within a subject by generating a compounded image frame having reduced motion artifacts. Ultrasound waves are transmitted into the structure and, for at least one sample volume location within an image plane of the structure, a set of received beams is formed in response to ultrasound waves backscattered from the structure such that the set of received beams intersect at the sample volume location. A compounded data value is generated corresponding to the at least one sample volume location within the image plane based on the corresponding set of received beams. A compounded image frame is formed from at least one compounded data value. Reduced-artifact, compounded imaging at frame rates that are acceptable for abdominal scanning in real-time is also achieved.

Abstract: A PACS including a source of medical data, such as a CT unit (20), a workstation (100) capable of creating an image of the data, and a local area network (40). A server (60) stores compressed medical data in a RAID (70) and also in a magneto-optical unit (80) and a tape DLT unit (90). The tape unit (90) has a transfer rate equal to or greater than the transfer rate of the RAID.

Abstract: Apparatus and methods for use in a diagnostic ultrasound system are disclosed. A display device has a first window for displaying live ultrasound images and a second window for displaying a reference cine image. The reference cine image is an image captured prior to the currently displayed live ultrasound images. The images of the first and second windows are synchronized by ECG gating. The apparatus and methods may be employed to image the heart, providing operators with a way to monitor the heart and detect subtle changes in heart condition from the time that a reference image was captured.

Abstract: A method and apparatus are disclosed for reducing variation in a spot size of an electron beam at a target due to multipole aberrations in an electron beam tomography (EBT) scanner. A magnitude of a DC voltage applied to a positive ion electrode (PIE) within the EBT scanner is adjusted and an orientation of a non-circular aperture of the PIE is aligned with respect to the electron beam. A profile of the spot size is monitored while adjusting the magnitude of the DC voltage and while aligning the orientation of the non-circular aperture of the PIE until the variation in the spot size is sufficiently reduced.

Abstract: A medical imaging system is provided for diagnostic and interventional procedures. The system includes a C-arm having an x-ray source and a receptor for obtaining fluoroscopic images of a patient. The C-arm is moved through an image acquisition path (A, B), along which at least first and second images are obtained. An acquisition module obtains multiple 2-D fluoroscopic images at desired positions along the image acquisition path and an image processor constructs a 3-D volume of object data based on the 2-D fluoroscopic images. Patient information is displayed based upon the 3-D volume of patient information. A position tracking system is included to track the position of the receptor, patient and (if included) a surgical instrument. The position information is used to control the time at which exposures are obtained and (if included) to superimpose instrument graphical information on a display with patient information.

Abstract: An x-ray system (14) including a source of x-rays (15) and a detector (22) monitors the detector with a control (36) that calibrates the detector during a calibration phase of operation and powers the detector during use phases of operation occurring at different times. A processor (28, 36) reads the data created by the pixel elements, analyzes the data and identifies pixel elements corresponding to data indicating defective pixel elements during the calibration phase of operation and during a predetermined portion of a plurality of the use phases of operation.

Abstract: An ultrasound system is disclosed that includes a method and apparatus to automatically adjust certain parameters that affect visualization of a Doppler spectral image. The ultrasound system acquires spectral lines of Doppler data generated by the ultrasound system. A data processor within the ultrasound system determines the presence of aliasing and estimates noise levels from the spectral lines of Doppler data. The data processor then automatically adjusts system parameters such as pulse repetition frequency (PRF), baseline shift, and spectrum orientation in response to aliasing and noise levels. The data processor of the ultrasound system also determines positive and negative signal boundaries for each spectral line of Doppler data and a display architecture processes the signal boundary data to display a spectral trace corresponding to the edges of the spectral lines.

Abstract: A method of detecting heart beat coincidence includes receiving first and second signals from first and second heart beat sources. The method further includes detecting first heart beat occurrences on the first signal, each first heart beat occurrence having a respective time associated therewith and detecting second heart beat occurrences on the second signal, each second heart beat occurrence having a respective time associated therewith. The method further includes comparing the times of the first and second heart beat occurrences to detect coincidence.

Abstract: A system and method of x-ray imaging is provided that includes a support base, a bearing assembly supported by the support base, and a non-circular positioning arm rotating in a semi-elliptical path relative to the support base through the bearing assembly. The non-circular positioning arm has first and second distal ends. The shape of the non-circular positioning arm conforms to a shape of a portion of a linear spiral. The system and method also includes an x-ray source located at the first distal end of the positioning arm, an x-ray detector located at the second distal end of the positioning arm. The x-ray source emits a conical beam having a theoretical central beam. The central beam passes through an origin of the linear spiral. The system also includes an imaging isocentric area located between the x-ray source and the x-ray detector. The imaging isocentric area remains substantially constant when the noncircular positioning arm rotates relative to the support base.

Abstract: A wireless local area network (WLAN) system comprises multiple access points that are distributed throughout a medical facility to provide wireless access to a hardwired network. The access points implement multiple WLAN protocols, including a realtime protocol for realtime patient monitoring (telemetry) and a standard WLAN protocol (such as IEEE 802.11 within an ISM band) for providing general-purpose wireless access. Some or all of the access points preferably implement both WLAN protocols such that the different WLANs and wireless device types share network access resources. Some or all of the access points may also include RF location-tracking modules which may be used to track locations of patients, hospital personnel, capital equipment, and/or disposable medical supplies.

Abstract: A method and apparatus are disclosed for monitoring multiple ultrasound scanners of differing platform types for system events, acquiring system event data of the ultrasound scanners, and transferring the system event data to a remote location by applying a common data mining module and log viewer component in each scanner to act as an interface between a web server and control processing section within the scanners. A computer at an automated support center that is remote to the scanners interfaces to the web servers of the scanners over a network. The remote computer has a web browser to survey the scanners by communicating with the web servers over the network. The data mining module continuously monitors the scanners for system events. Log files are generated within the scanners during normal operation of the scanner. The log viewer component translates system event log files within the scanners in response to internal requests occurring in the scanners at regular, pre-defined time intervals.

Abstract: Certain embodiments include a system and method for collision avoidance in a patient positioning system. The system includes a patient positioning surface, a position sensor for determining a position of the patient positioning surface, and a control subsystem for controlling operation of the patient positioning system. The control subsystem dynamically determines a clearance distance between the patient positioning surface and the object. The control subsystem halts motion of the patient positioning surface if the clearance distance is less than or equal to a minimum safe clearance distance. The control subsystem may dynamically determine the clearance distance before, during, and/or after motion of the patient positioning surface.

Abstract: An ultrasound machine is disclosed that displays a color representation of moving structure, such as a cardiac wall tissue, within a region of interest on a monitor. The color representation is generated by displaying color hues corresponding to a movement parameter of the structure, such as velocity or strain rate in such a manner as to provide for quantitative visualization of movement parameter gradients. The movement parameter is mapped to the color hues by apparatus comprising a user interface that allows the user to input color band resolution and a local range of relative parameter values. A front-end generates received signals in response to ultrasound waves. A Doppler processor generates a set of parameter signals representing absolute values of the movement parameter within the structure. A set of color characteristic signals is generated by a display processor in response to the set of parameter signals and to a user-defined local range of relative parameter values.

Abstract: Various designs and features of an ambulatory transceiver and ECG lead set are disclosed for use in remote patient monitoring. One feature involves the use of unshielded, dual-conductor lead wires in which one conductor carries the patient's ECG signal and the other conductor provides an RF antenna element for the transceiver. The lead wires used in one embodiment provide improved flexibility, durability, and antenna performance over conventional lead sets with shielded wires. Another feature involves an antenna diversity scheme in which the transceiver switches between two or more ECG-lead antennas, each of which is formed from one or more ECG leads of the lead set. Another feature involves the use of a circuit within the transceiver to monitor, and dynamically compensate for changes in, the impedance of an ECG-lead antenna or a conductor thereof. Another feature is an improved circuit for protecting the transceiver from damage caused by defibrillation pulses.