Abstract: Systems and methods for discriminating and locating tissues within a body involve applying a waveform signal to tissue between two electrodes and measuring the electrical characteristics of the signal transmitted through the tissue. At least one of the electrodes is constrained in area so that localized electrical characteristics of the tissue are measured. Such localized electrical characteristics are determined over a portion of a body of the subject by using an array of electrodes or electrodes that can be moved over the body. A controller may implement the process and perform calculations on the measured data to identify tissue types and locations within the measured area, and to present results in graphical form. Results may be combined with other tissue imaging technologies and with image-guided systems.

Abstract: Systems and methods for discriminating and locating tissues within a body involve applying a waveform signal to tissue between two electrodes and measuring the electrical characteristics of the signal transmitted through the tissue. At least one of the electrodes is constrained in area so that localized electrical characteristics of the tissue are measured. Such localized electrical characteristics are determined over a portion of a body of the subject by using an array of electrodes or electrodes that can be moved over the body. A controller may implement the process and perform calculations on the measured data to identify tissue types and locations within the measured area, and to present results in graphical form. Results may be combined with other tissue imaging technologies and with image-guided systems.

Abstract: A method or a system embodiment determines positional information about a moveable object to which is affixed a pattern of stripes having reference lines. A method determines image lines of stripe images of each stripe within at least two video frames, uses the image lines to prescribe planes having lines of intersection, and determines a transformation mapping reference lines to lines of intersection. Position information about the object may be derived from the transformation. A system embodiment comprises a pattern of stripes in a known fixed relationship to an object, reference lines characterizing the stripes, two or more cameras at known locations, a digital computer adapted to receive video frames from the pixel arrays of the cameras, and a program stored in the computer's memory. The program performs some or all of the method.

Abstract: The shape and orientation of rigid or nearly rigid moveable bodies are determined using a shape characterization. Sensors capture a plurality of representations of different perspectives of the body that are analyzed to determine a bounding volume of the body. The shape of the body is determined from the bounding volume. The position of the body is determined using tracking devices that sense the position of the body. The bounding volume and position information are combined to define the shape and orientation in space of the body, and in particular the position of a point of interest on the body.

Abstract: A sensor for determining a component of a location of a radiation source within a three dimensional volume includes a mask having a series of openings that has a predetermined mathematical relationship among the openings within the series of openings and defines a mask reference line; a detector surface spaced from the mask where radiation passing through the mask creates a mask image on the detector surface having a series of peaks and an image reference line within the mask image that can be located and where at least 50% of the mask image is projected onto the detection surface; and a calculating unit to determine a location of the image reference line within the mask image and the component of the location of the radiation source from the calculated location of the image reference line within the mask image. A method and system for using this sensor are also disclosed.

Abstract: A sensor for determining a component of a location of a radiation source within a three dimensional volume includes a mask having a series of openings that has a predetermined mathematical relationship among the openings within the series of openings and defines a mask reference line; a detector surface spaced from the mask where radiation passing through the mask creates a mask image on the detector surface having a series of peaks and an image reference line within the mask image that can be located and where at least 50% of the mask image is projected onto the detection surface; and a calculating unit to determine a location of the image reference line within the mask image and the component of the location of the radiation source from the calculated location of the image reference line within the mask image. A method and system for using this sensor are also disclosed.

Abstract: This invention is a system that tracks the 3-dimensional position and orientation of one or more bodies (20) in a volume by a light based as well as at least one non-light based mensuration sub-system. This overcomes the limitation of light based mensuration systems to the necessity of the bodies (20) to be in constant line-of-sight of its light based position sensors (26). The invention possesses most of the accuracy and stability of its light based position measurement sub-system (24, 26, 72), but can also work without direct line of sight either for short periods of time or within certain parts of the volume. It does so by incorporating other sensors (31, 34), such as inertial or magnetic, which are frequently recalibrated against the light based sub-system (24, 26, 72) while the bodies (20) are visible by the light based sub-system (24, 26, 72).

Abstract: Disclosed is a wireless instrument tracking system. The wireless instrument tracking system is used for determining the location of at least one point relative to the instrument in a three-dimensional space relative to a three-dimensional coordinate tracking system. Advantageously, a first wireless instrument can be placed into the optical field with the wireless instrument including a wireless receiver and at least one optical position indicator. The optical position indicator is typically light emitting diodes (18) and communicates with corresponding measurement sensors (30) across a wireless optical link. The wireless optical link is time multiplexed with repetitive time frames divided into time slots. Each LED (18) emits an infrared signal or flashes in a respective time slot of a time frame. The measurement sensors (30) are preferably CCD cameras.

Abstract: An optical improvement for angular position sensors, which may be used to determine the spatial coordinates of a small source of light (or other energy) in a 3-dimensional volume. Such sensors normally include a linear photosensitive image detector such as a photodiode array or a charge-coupled device (CCD). An irregular pattern of parallel slits is described which increases the amount of light gathered while avoiding the undesirable characteristics of lens optics for this application. One optimal type of irregular pattern is the uniformly redundant array. A mathematical correlation function together with a polynomial interpolation function can determine the displacement of the image on the detector and thereby the location of the source relative to one angular dimension. Given the locations and orientations of several sensors in a 3-dimensional coordinate system and given the angles measured by each, the location of the point source can be computed.

Abstract: System for sensing at least two points on an object for determining the position and orientation of the object relative to another object. Two light emitters mounted in spaced relation to each other on an external portion of an invasive probe remaining outside an object into which an invasive tip is inserted are sequentially strobed to emit light. Three light sensors or detectors, the positions of which are known with respect to a predetermined coordinate system, detect the positions of the two light emitters positioned on the probe. A computer connected to the probe and to the light sensors receives data from the sensors and determines the position and orientation of the probe relative to the predetermined coordinate system.

Abstract: Locating and displaying the relative positions of two objects in a three-dimensional space where one object is a three-dimensional object and the second object has at least three collinear points, at least two of which are sensible by a detector. The detector supplies signals providing azimuth and altitude information related to the two sensible points of the second object for locating the position of at least the third point of the second object relative to the first object which may be positioned inside or outside the boundaries of the first object. The first object may have fixed thereto at least three points sensible by the detector for establishing the position and attitude of the first object within the three-dimensional space.

Abstract: Improved point source electromagnetic radiation emitters including a dispersing element that radiates electromagnetic radiation over a very wide conical angle of approaching about 180.degree.. This light dispersing element can be in any one or more of several illustrated forms such as a light diffusing spherical or hemispherical element, a planar diffusing plate, a tapered light guide, a plano-concave lens, a convex mirror, a light pipe with a large numerical aperture, or the like. The emitter of this invention may be fixed to an object and tracked in a 3-dimensional volume by a system using electro-optical position sensors in order to determine the spatial location of the emitters and therefore to determine, by geometry, the position and orientation of the object. The electromagnetic radiation generator is preferably disposed remote from the emitter and is electrically and magnetically isolated from the emitter. A common optical fiber provides transmission of the radiation from the generator to the emitter.

Abstract: System for sensing at least two points on an object for determining the position and orientation of the object relative to another object. Two light emitters mounted in spaced relation to each other on an external portion of an invasive probe remaining outside an object into which an invasive tip is inserted are sequentially strobed to emit light. Three light sensors or detectors, the positions of which are known with respect to a predetermined coordinate system, detect the positions of the two light emitters positioned on the probe. A computer connected to the probe and to the light sensors receives data from the sensors and determines the position and orientation of the probe relative to the predetermined coordinate system.

Abstract: The invention provides an improved imaging system and method. The imaging system is of the type having a medical instrument including a source for emitting detectable energy and an instrument body having a work portion. The imaging system further includes detector for detecting the energy and a processor for determining the location of the medical instrument based on the detected energy. Such an imaging system is improved by providing a storage device on or in the medical instrument for storing initialization information, such as the location of the energy-emitting means relative to the instrument body. A transfer device is provided for transferring the initialization information from the storage device to the processor upon connection of the medical instrument to the processor. In this manner, the processor may then configure itself according to the attached instrument so that the system may track the location of the instrument body in three-dimensional space upon detection of the emitted energy.

Abstract: This method and apparatus optically samples numerous points on the surface of an object to remotely sense its shape utilizing two stages. The first stage employs a moveable non-contact scanner, which in normal operation sweeps a narrow beam of light across the object, illuminating a single point of the object at any given instant in time. The location of that point relative to the scanner is sensed by multiple linear photodetector arrays behind lenses in the scanner. These sense the location by measuring the relative angular parallax of the point. The second stage employs multiple fixed but widely separated photoelectronic sensors, similar to those in the scanner, to detect the locations of several light sources affixed to the scanner, thereby defining the absolute spatial positions and orientations of the scanner. Individual light sources are distinguished by time-multiplexing their on-off states.

Abstract: Improved point source electromagnetic radiation emitters including a dispersing element that radiates electromagnetic radiation over a vary wide conical angle of approaching about 180°. This light dispersing element can be in any one or more of several illustrated forms such as a light diffusing spherical or hemispherical element, a planar diffusing plate, a tapered light guide, a piano-concave lens, a convex mirror, a light pipe with a large numerical aperture, or the like. The emitter of this invention may be fixed to an object and tracked in a 3-dimensional volume by a system using electro-optical position sensors in order to determine the spatial location of the emitters and therefore to determine, by geometry, the position or orientation of the object. The electromagnetic radiation generator is preferably disposed remote from the emitter and is electrically and magnetically isolated from the emitter. A common optical fiber provides transmission of the radiation from the generator to the emitter.

Abstract: This method and apparatus optically samples numerous points on the surface of an object to remotely sense its shape utilizing two stages. The first stage employs a moveable non-contact scanner, which in normal operation sweeps a narrow beam of light across the object, illuminating a single point of the object at any given instant in time. The location of that point relative to the scanner is sensed by multiple linear photodetector arrays behind lenses in the scanner. These sense the location by measuring the relative angular parallax of the point. The second stage employs multiple fixed but widely separated photoelectronic sensors, similar to those in the scanner, to detect the locations of several light sources affixed to the scanner, thereby defining the absolute spatial positions and orientations of the scanner. Individual light sources are distinguished by time-multiplexing their on-off states.