Abstract: The invention relates to A method for imaging jointed movable parts of an object by magnetic resonance, where a third part of the object moves along a trajectory near a pivot between a first and a second part of the object, and where the position of the third part is dependent, in conformity with a predetermined relation, on an orientation of the first and the second part relative to the pivot. The method is used, for example for forming a series of images of the patella during the movement of the knee of a human body. According to the method, the measuring zone is adjusted to the instantaneous position of the patella in order to generate imaging pulse sequences. An angle formed by the orientations of the lower leg and the upper leg with respect to one another is measured in order to determine the instantaneous position of the patella. The angle can be determined from the position of RF coils fastened to the lower leg and the upper leg.

Abstract: An inspection apparatus using nuclear magnetic resonance having arithmetic and control means for controlling a pulse sequence for detecting a nuclear magnetic resonance signal from a target to be inspected and calculating the detected signal.

Abstract: In magnetic resonance imaging (MRI) apparatus in which weight considerations and accessibility of the patient result in a magnet 1 with a large bore 2, in order to enable spectroscopy or other activities requiring large magnetic fields to nevertheless be carried out, a small magnet 4 with its own cryostat can be moved from an inoperative position A to an operative position B, in which the large magnet acts as a shield winding for the small magnet.

Abstract: An apparatus for sensing muscular activity of the rectosigmoid region, rectum, and the anorectal canal of a subject is disclosed. This apparatus includes an elongate probe having a distal end opposing a proximal end which is configured for insertion into the patient's anorectal canal and includes a pressure sensor, an electromyography sensor, and a stimulus balloon. Multiple pressure sensors may be included to evaluate muscular activity in the anorectal canal. In addition, pressure sensors may be distributed along the length of the probe to simultaneously measure the response of other portions of the anorectal canal besides the anal sphincter muscle. A pressure sensor is also located inside the stimulus balloon for monitoring intraballoon pressure.

Abstract: A pneumatic control device includes a housing, a pressure control member secured to the housing, a first fluid-conduit member, and a first sensor. The pressure control member is constructed and arranged to selectively change a fluid pressure within the control member. The first fluid-conduit member is in fluid-flow communication with the pressure control member. The first sensor is in fluid-flow communication with the first fluid-conduit member. The sensor is constructed and arranged to generate a control signal based upon the fluid pressure within the control member. In preferred systems, the pneumatic controller is useful for producing a variable control signal to control a rate of fluid dispersement to a patient in an angiographic system.

Abstract: A method for predicting peripheral nerve damage comprising the steps of placing a pressure transducer on the skin of a patient proximate to a peripheral nerve; measuring the pressure with the pressure transducer over time; and estimating a damage to the nerve based on the pressure and duration of application and a nerve damage model.

Abstract: A graphical user interface (GUI) is provided for assisting medical personnel in interpreting data collected by a multiple electrode catheter deployed within the body. The GUI generates and displays an image of the multiple electrode catheter. By manipulating appropriate controls, the medical personnel are able to change the orientation of the displayed image until it matches the orientation of the actual multiple electrode catheter as seen on a fluoroscope. Afterwards, the medical personnel can determine the relative position and orientation of the catheter by reference to the GUI generated image. To aid in interpreting data recovered by the catheter, the individual electrodes and splines are highlighted and labeled. Electrodes recovering particular types of physiological waveforms can be automatically identified and highlighted. Comments and anatomic landmarks can be inserted where desired to further assist in interpreting data.

Abstract: A method of positioning a catheter, for example a balloon or treatment catheter. The catheter is inserted in a passage and sensed through the luminal wall to correctly determine its position. As applied to prevent hemorrhage during surgery the method involves inserting the catheter in a deflated configuration along a passage such as a blood vessel near to the operative site in a position determined by direct or video-assisted sensing from outside the passage. In the event a blood vessel is cut during surgery, the already-positioned catheter inflates a balloon to occlude the passage and stop blood flow into the injured site. In one aspect, a flow-directed catheter includes an inflatable balloon attached at its distal end and an optical fiber connected to one or more light emitting regions positioned at the tip or in the vicinity of the balloon.

Abstract: A method of acoustically imaging a portion of the morphology of a subject which includes the steps of utilizing a burst of pulses for which reflections are recorded prior to analyzing and plotting the data generated thereby.

Abstract: The alternating magnetic field gradient used to sensitize an NMR signal to spin motion is modulated in amplitude with a window function to tailor it to the particular NMR measurement. In an MR elastography measurement, the gradient is a sinusoidal waveform having a frequency the same as an applied oscillatory stress, and the window function desensitizes the measurement to spin motions at other frequencies.

Abstract: A method for performing motion-compensated spectral-spatial selective magnetic resonance imaging. The method includes applying a radio frequency (RF) spectral-spatial excitation pulse sequence to a region of a body. The excitation sequence includes a binomial pulse train including at least two sub-pulses. The binomial pulse train also provides spectrally selective excitation of a selected resonance frequency at the predetermined field strength. The method also includes applying to the same body region an oscillating slice selection gradient so that each sub-pulse of the binomial pulse train is applied during portions of the oscillating gradient having the same polarity. The oscillating gradient further includes at least one extra gradient switch added to the end of the oscillating gradient for providing a balanced gradient for inherently motion-compensated slice selection.

Abstract: The sensitivity in detection in a depth direction of a living body and the overall signal-to-noise ratio of an apparatus are improved, whereby a distribution of current sources in the living body or a plurality of current dipoles can be inferred more accurately than they conventionally are. A pickup coil array is made by combining a plurality of types of pickup coils that are mutually different in at least one of the order of a differential and a base line. The plurality of types of pickup coils are mutually different in, for example, only the order of a differential or only a base line, and are arranged separately at different measurement points or arranged at the same measurement point. Included is a magnetic source inferring means for inferably computing information on magnetic sources in a living body or information on the distribution of magnetic sources on the basis of detection signals provided by the plurality of types of pickup coils.

Abstract: An optical coupling is incorporated into an invasive device used in magnetic resonance (MR) imaging. The coupling is incorporated into the invasive device between an imaging or tracking RF coil, and the MR receiver. The optical coupling has a first transducer circuit coupled to the RF which converts between optical and electrical signals. An optical fiber is coupled to the first transducer circuit and extends out of the invasive device to medical imaging equipment. Near this equipment, a second transducer circuit converts optical signals to electrical, and electrical signals to optical, just opposite that of the first transducer circuit. The present invention thereby replaces long lead wires which can cause heating during MR imaging, and may distort an MR image.

Abstract: A dynamic MRA study of a subject is performed using a 3D fast gradient-recalled echo pulse sequence. The frame rate of the resulting series of reconstructed images is increased by sampling a central region of k-space at a higher rate than the peripheral regions of k-space. Artifacts caused by variations in signal strength as the contrast agent enters the region of interest are reduced by renormalizing the acquired data. 2D image frames are reconstructed using planes passing near the center of k-space to enable the operator to select which 3D data sets should be used to reconstruct diagnostic images.

Abstract: Uterine activity is sensed by passing light through the patient's abdominal wall and detecting the light reflected from abdominal tissues. The intensity of the reflected light varies with the state of contraction of the patient's uterus. The use of light for monitoring uterine activity avoids the problems of size, fixation, and measurement accuracy exhibited by the conventional tocodynamometer technique.

Abstract: Apparatus and method are described for introducing an imaging catheter to the coronary vasculature. A guiding catheter is introduced so that the distal end of the guiding catheter engages a coronary os. The distal end of the guiding catheter is shaped so that a mark on the distal end is oriented in a predetermined orientation relative to the coronary vasculature. An imaging catheter is then introduced through the guiding catheter and an image of the mark is produced with the imaging catheter while in the guiding catheter. In this manner, the relative orientation of the produced image and the coronary vasculature is known.

Abstract: The present invention provides a method and apparatus for illuminating the region of a body member to be subjected to a surgical procedure by inserting an infrared conducting fiber into the body member, the fiber emitting infrared light energy over a limited range at the precise location where the procedure is to occur. The procedure may involve an organ, a blood vessel, even a nerve. Mechanisms and detectors may be employed to locate the infrared emissions.

Abstract: A method and coil arrangement for use in magnetic resonance imaging facilitates the examination of a localized region of the body. A plurality of substantially identical saddle coils are disposed about a former. The coils, which define a generally cylindrical volume, overlap one another in a circumferential direction. In one embodiment, a generally planar rectangular coil intersects the cylindrical volume. The method and coil arrangement are particularly well suited to imaging a region adjacent but outside the cylindrical volume. The coil arrangement is also well suited to insertion within the body, especially the rectum.

Abstract: A system for determining a position of a probe relative to an object such as a head of a body of a patient. The head includes a surface such as a forehead having a contour. Cross sectional images of the head are scanned and stored as a function of the forehead contour. If the forehead contour does not appear in the scan images, then the position of the forehead contour relative to the scan images is determined with an optical scanner and a ring. During surgery, the optical scanner also determines the position of the forehead relative to the ring. An array for receiving radiation emitted from the probe and from the ring generates signals indicating the position of the tip of the probe relative to the ring. A stereotactic imaging system generates and displays an image of the head corresponding to the measured position of the tip of the probe. The system may also display scan images from different scanning technologies which scan images correspond to the same position in the head.

Abstract: After exciting dipoles in an examination region (60), a train of magnetic resonance echoes including echoes (66.sub.1, 66.sub.2, . . . ) is induced, e.g., with a series of refocusing pulses including pulses (68.sub.1, 68.sub.2, . . . ). The echoes are phase and frequency-encoded. A receiver 38 is gated by a gate circuit (82) to sample the even echoes (66.sub.2 -66.sub.10) and the odd echoes (66.sub.5 -66.sub.10) that occur after a threshold odd echo such as the third echo (66.sub.3) so as to generate an image of a common physical region which exhibits reduced motion artifacts.