Abstract: Miniaturized, five and six degrees-of-freedom magnetic sensors, responsive to pulsed DC magnetic fields waveforms generated by multiple transmitter options, provide an improved and cost-effective means of guiding medical instruments to targets inside the human body. The end result is achieved by integrating DC tracking, 3D reconstructions of pre-acquired patient scans and imaging software into a system enabling a physician to internally guide an instrument with real-time 3D vision for diagnostic and interventional purposes. The integration allows physicians to navigate within the human body by following 3D sensor tip locations superimposed on anatomical images reconstructed into 3D volumetric computer models. Sensor data can also be integrated with real-time imaging modalities, such as endoscopes, for intrabody navigation of instruments with instantaneous feedback through critical anatomy to locate and remove tissue.

Abstract: Methods for accurately tracking position and orientation of a magnetic-field sensor in a tracking volume when a large magnetic-field distorter is present in the tracking volume. In some of the methods, magnetic field data is collected from within the tracking volume both with and without the large magnetic-field distorter present in the tracking volume. This data is used to obtain correction information that is subsequently used during real-time operation of the magnetic-field sensor to correct the position and orientation solutions for the sensor for magnetic-field distortions caused by the presence of the large magnetic-field distorter in the tracking volume. Others of the methods involve modeling the large magnetic-field distorter using dipole and multipole modeling. Magnetic tracking systems for implementing the methods include hardware and software for carrying out the methods.

Abstract: Miniaturized, five and six degrees-of-freedom magnetic sensors, responsive to pulsed DC magnetic fields waveforms generated by multiple transmitter options, provide an improved and cost-effective means of guiding medical instruments to targets inside the human body. The end result is achieved by integrating DC tracking, 3D reconstructions of pre-acquired patient scans and imaging software into a system enabling a physician to internally guide an instrument with real-time 3D vision for diagnostic and interventional purposes. The integration allows physicians to navigate within the human body by following 3D sensor tip locations superimposed on anatomical images reconstructed into 3D volumetric computer models. Sensor data can also be integrated with real-time imaging modalities, such as endoscopes, for intrabody navigation of instruments with instantaneous feedback through critical anatomy to locate and remove tissue.

Abstract: Miniaturized, five and six degrees-of-freedom magnetic sensors, responsive to pulsed DC magnetic fields waveforms generated by multiple transmitter options, provide an improved and cost-effective means of guiding medical instruments to targets inside the human body. The end result is achieved by integrating DC tracking, 3D reconstructions of pre-acquired patient scans and imaging software into a system enabling a physician to internally guide an instrument with real-time 3D vision for diagnostic and interventional purposes. The integration allows physicians to navigate within the human body by following 3D sensor tip locations superimposed on anatomical images reconstructed into 3D volumetric computer models. Sensor data can also be integrated with real-time imaging modalities, such as endoscopes, for intrabody navigation of instruments with instantaneous feedback through critical anatomy to locate and remove tissue.

Abstract: A system for tracking the location of a magnetic stimulation coil.

Abstract: An electromagnetic tracking system and a distortion compensation method that utilize a lead-lag network model to compensate for position and orientation distortion caused by eddy currents formed in one more conductive distorters located within a tracking environment during electromagnetic tracking of one or more objects. The method is adaptive relative to the amount of distortion cause by the conductive distorters.

Abstract: Methods for accurately tracking position and orientation of a magnetic-field sensor in a tracking volume when a large magnetic-field distorter is present in the tracking volume. In some of the methods, magnetic field data is collected from within the tracking volume both with and without the large magnetic-field distorter present in the tracking volume. This data is used to obtain correction information that is subsequently used during real-time operation of the magnetic-field sensor to correct the position and orientation solutions for the sensor for magnetic-field distortions caused by the presence of the large magnetic-field distorter in the tracking volume. Others of the methods involve modeling the large magnetic-field distorter using dipole and multipole modeling. Magnetic tracking systems for implementing the methods include hardware and software for carrying out the methods.

Abstract: An electromagnetic tracking system and a distortion compensation method that utilize a lead-lag network model to compensate for position and orientation distortion caused by eddy currents formed in one more conductive distorters located within a tracking environment during electromagnetic tracking of one or more objects. The method is adaptive relative to the amount of distortion cause by the conductive distorters.

Abstract: An electromagnetic tracking system (600) and a distortion compensation method (500) that utilize a lead-lag network model to compensate for position and orientation distortion caused by eddy currents formed in one or more conductive distorters (330, 658A-C) located within a tracking environment during electromagnetic tracking of one or more objects (612). the method is adaptive relative to the amount of distortion cause by the conductive distorters.

Abstract: Splines of magnetic field values are used by a processor to determine location parameters in a remote location determination system. The location determination system is used on a laser catheter that is operable to perform myocardial revascularization. An automatic calibration technique compensates for any variations in gain in a sensor and related components. Methods for reducing the effects of eddy currents in surrounding conductive objects are used in electromagnetic position and orientation measurement systems.

Abstract: A distortion immune tablet (20) for a position and orientation system (22). The tablet includes a plurality of magnetic field generators (40), a layer of magnetic material (60) and a layer of conductive, non-magnetic material (80). The coils (42) of the generators are oriented relative to the magnetic layer so that the magnetic layer regularly distorts the magnetic fields produced by the generators by creating a positive image of the fields substantially on one side of the magnetic layer. Portions of the magnetic fields passing through the magnetic layer are eliminated by the conductive layer via eddy current effects. The position and orientation system further includes a processor (24) for providing drive signals to the generators and a sensor (26) for sensing the magnetic fields produced by the generators.

Abstract: Method of cooling electronic systems an semiconductor devices as well as an electronic system and a semiconductor device with heat dissipating elements. The method includes the steps of providing an electronic system or a semiconductor device with a heat sink including at least a first element having a generally flat shape with a shoulder projecting from one generally flat surface, and configured to thermally engage similar elements. In one embodiment, a first and a second heat sink element are provided, with one of the first and second elements having a protrusion and the other of the first and second elements defining a depression configured to receive and retain said protrusion. Alternatively, the first and second elements may be bonded together with a thermally conductive adhesive.

Abstract: A semiconductor die is mounted to a die receiving area, which is defined by inner ends of conductive leads to which the die is connected. The die is temporarily retained in a substantially fixed position relative to the die receiving area by various techniques for the purpose of permitting bond wires to be attached between the conductive leads and the die. Preferred techniques include employing a mechanical chuck, dispensing an adhesive between the die and its die receiving area, and forming an ultrasonic bond between the die and the die receiving area. Once electrical connections between the die and the conductive lines are formed, the die need not be retained in a fixed position, as the electrical connections will provide sufficient support for the die. Accordingly, conventional die attach techniques, which expose the semiconductor die to substantially elevated temperatures, are avoided.

Abstract: An integrated circuit package having a die supported on a ball grid array substrate and wire bonds electrically connecting the die to the substrate. Supported on the substrate is a lock ring having a threaded opening encircling the die. Encapsulant covers the die and the wire bonds and adheres the lock ring to the substrate. A heat sink having a threaded portion can be threaded into the lock ring into an operative cooling position relative to the die and subsequently to an unthreaded removed position. When in the latter position, a repair station can be positioned over the package and the solder balls are accessible for hot gas melting thereof for removal (or replacement) of the package from the underlying motherboard.

Abstract: Apparatus for use in cooling an integrated circuit structure. The apparatus includes a heat sink having a first portion configured for thermal engagement with an integrated circuit device and a second portion configured for the dissipation of heat into an ambient fluid, such as air. The heat sink is made from a powdered metal which, in one preferred embodiment, includes copper. The heat sink may be formed from the plurality of discrete layers, each layer having a button projecting from one surface, and a depression formed in an opposing surface. The depression is configured to receive a projecting button portion from another layer. In an alternative embodiment the heat sink includes a plurality of plugs projecting from the generally flat surface.

Abstract: An integrated circuit package having a die supported on a ball grid array substrate and wire bonds electrically connecting the die to the substrate. Supported on the substrate is a lock ring having a threaded opening encircling the die. Encapsulant covers the die and the wire bonds and adheres the lock ring to the substrate. A heat sink having a threaded portion can be threaded into the lock ring into an operative cooling position relative to the die and subsequently to an unthreaded removed position. When in the latter position, a repair station can be positioned over the package and the solder balls are accessible for hot gas melting thereof for removal (or replacement) of the package from the underlying motherboard.

Abstract: An electronic system having improved thermal transfer from a semiconductor die in a semiconductor device assembly (package) by at least partially filling a cavity in the package with a thermally conductive fluid, immersing a heat collecting portion of a heat pipe assembly into the fluid, and sealing the cavity. In order that the thermally conductive fluid does not chemically attack the die or its electrical connections, the die and connections can be completely covered with an encapsulating coating of an inorganic dielectric material, such as silicon dioxide, by any of a variety of techniques. The heat pipe provides highly efficient heat transfer from within the package to an external heat sink by means of an evaporation-condensation cooling cycle. The optional dielectric coating over the die permits selection of the thermally conductive fluid from a wider range of fluids by isolating the die and its electrical connections from direct contact with the fluid.

Abstract: Electronic systems utilizing a plurality of integrated circuit packages having a stackable heat sink assembly is formed by press-fit assembly of two or more identical fin layers. Each fin layer is formed using powdered metallurgy and has a button-like projection extending from its bottom surface and a recess opening in its top surface. The button-like projection and recess opening are sized and shaped such that an interference fit is formed when the buttonlike projection of one fin layer is pressed into the recess of another fin layer. The use of an adaptor to increase or decrease the effective size of the button-like projection of the bottom-most fin layer is described. Relieving gases that may be entrapped in the recess during assembly is described. Circular, elliptical and polygonal shapes (outlines) for the fin layers are described.

Abstract: A ball bump grid array package includes dies on one surface of a printed wiring board (PWB) and an array of ball bumps on the other surface of the PWB. The die is interconnected with the ball bumps by bond wires, traces on the one surface of the PWB, vias through the PWB and traces on the other surface of the PWB. Various die encapsulation schemes are discussed. The PWB is formed of FR4, BT, teflon or polyimide, or ceramic materials. The die may be connected to the traces on the one surface of the PWB with solder balls, rather than with bond wires. Two or more dies may be disposed on the one surface of the PWB, within the plastic molded body. The ball bumps on the other surface of the PWB may be arranged in a multiple grid pitch array--ball bumps within a central area being on a first pitch, and ball bumps without the central area being on a second pitch which is a multiple of the first pitch.

Abstract: Method of cooling electronic systems and semiconductor devices as well as an electronic system and a semiconductor device with heat dissipating elements. The method includes the steps of providing an electronic system or a semiconductor device with a heat sink including at least a first element having a generally flat shape with a shoulder projecting from one generally flat surface, and configured to thermally engage similar elements. In one embodiment, a first and a second heat sink element are provided, with one of the first and second elements having a protrusion and the other of the first and second elements defining a depression configured to receive and retain said protrusion. Alternatively, the first and second elements may be bonded together with a thermally conductive adhesive.