Abstract: A stent comprises a plurality of undulating circumferential portions, each circumferential portion comprising alternating peaks and valleys; and a plurality of longitudinally extending portions connecting the plurality of undulating circumferential portions. Each of the plurality of longitudinally extending portions contains a first longitudinally extending strut and a second longitudinally extending strut circumferentially offset with respect to the first longitudinally extending strut. The first longitudinally extending strut and the second longitudinally extending strut are interconnected by a connecting portion. Circumferentially adjacent first longitudinally extending struts in a pair of circumferentially adjacent longitudinally extending portions are circumferentially spaced at a first distance and circumferentially adjacent second longitudinally extending struts in the pair of circumferentially adjacent longitudinally extending portions are circumferentially spaced at a second distance.

Abstract: A stent comprises a plurality of undulating circumferential portions, each circumferential portion comprising alternating peaks and valleys; and a plurality of longitudinally extending portions connecting the plurality of undulating circumferential portions. Each of the plurality of longitudinally extending portions contains a first longitudinally extending strut and a second longitudinally extending strut circumferentially offset with respect to the first longitudinally extending strut. The first longitudinally extending strut and the second longitudinally extending strut are interconnected by a connecting portion. Circumferentially adjacent first longitudinally extending struts in a pair of circumferentially adjacent longitudinally extending portions are circumferentially spaced at a first distance and circumferentially adjacent second longitudinally extending struts in the pair of circumferentially adjacent longitudinally extending portions are circumferentially spaced at a second distance.

Abstract: A stent comprises a plurality of undulating circumferential portions, each circumferential portion comprising alternating peaks and valleys; and a plurality of longitudinally extending portions connecting the plurality of undulating circumferential portions. Each of the plurality of longitudinally extending portions contains a first longitudinally extending strut and a second longitudinally extending strut circumferentially offset with respect to the first longitudinally extending strut. The first longitudinally extending strut and the second longitudinally extending strut are interconnected by a connecting portion. Circumferentially adjacent first longitudinally extending struts in a pair of circumferentially adjacent longitudinally extending portions are circumferentially spaced at a first distance and circumferentially adjacent second longitudinally extending struts in the pair of circumferentially adjacent longitudinally extending portions are circumferentially spaced at a second distance.

Abstract: A stent comprises a plurality of undulating circumferential portions, each circumferential portion comprising alternating peaks and valleys; and a plurality of longitudinally extending portions connecting the plurality of undulating circumferential portions. Each of the plurality of longitudinally extending portions contains a first longitudinally extending strut and a second longitudinally extending strut circumferentially offset with respect to the first longitudinally extending strut. The first longitudinally extending strut and the second longitudinally extending strut are interconnected by a connecting portion. Circumferentially adjacent first longitudinally extending struts in a pair of circumferentially adjacent longitudinally extending portions are circumferentially spaced at a first distance and circumferentially adjacent second longitudinally extending struts in the pair of circumferentially adjacent longitudinally extending portions are circumferentially spaced at a second distance.

Abstract: An expandable dilation catheter advantageously useful to deliver and orient an endovascular prosthesis with respect to a target body passageway. The catheter comprises a first tubular member disposed in a proximal portion of the portion of the catheter and a second tubular member disposed in a distal portion of the catheter. The first tubular member and the second tubular member are in a spaced relationship with respect to one another. An expandable member (e.g., a balloon) is disposed distally of the second tubular member. A first lumen and a second lumen disposed in each of the first tubular member and in the second tubular member. The first lumen is in communication with an interior of the expandable member to function as an inflation lumen and the second lumen serves to receive a first guidewire. The first tubular member and second tubular member are interconnected by a coupling member.

Abstract: An apparatus and method for causing necrosis of tissue and specifically intended for thermal ablation of the uterine cavity to cauterizing the endometrial tissue. The apparatus includes a liquid-tight, liquid filled system having a distal flexible member; a proximal flexible member; and a catheter joining and providing a liquid path between these distal and proximal members. The apparatus further includes a pressurizable pneumatic chamber into which the proximal flexible member is inserted and a means to controllably heat the contents of the pneumatic chamber. The system operates to: first withdraw substantially all of the liquid into the proximal flexible member contained within the pressurizable pneumatic chamber; second to heat this liquid to a temperature such that it can cause tissue necrosis; and third to force the heated liquid from the proximal flexible member into the distal flexible member where it is maintained for a predetermined time and at a predetermined pressure.

Abstract: Magnetic resonance apparatus is provided comprising a magnet having a plurality of pairs of coils arranged in respective substantially parallel planes. The coils in each pair are operable in a counter-running manner when in use so as to generate a region of magnetic field spaced apart from said planes, having sufficient uniformity to enable magnetic resonance signals to be obtained from a target within the region. The magnetic field has a magnetic field direction Z lying substantially parallel to said planes and each of the coils is elongate in a direction X substantially parallel to said planes.

Abstract: A magnetic resonance apparatus comprises a magnet system for generating a magnetic field in a working volume. Magnetic gradient coils are used to generate one or more magnetic field gradients in the working volume so as to define regions from which magnetic resonance signals are obtained from a target material. A controller operates the gradient coils in use so as to apply one or more magnetic field gradients within each region. For each of the defined regions, the controller performs a method in which the one or more magnetic field gradients are controlled in accordance with the position of the said region with respect to the gradient coils, such that the one or more magnetic field gradients have a predetermined uniformity, thereby increasing the uniformity within regions at the periphery of the working volume.

Abstract: A magnetic field generating assembly comprising a set (A1-A3;B1-B3;C1-C3) of, typically substantially coaxial, coils substantially symmetrically arranged about a plane orthogonal to the axis. At least some of the coils carry working currents in the opposite sense to the other coils The arrangement of turns and working currents carried by the coils is such that a first working volume (10) with a substantially homogeneous magnetic field is generated within the envelope defined by the assembly, and two second working volumes (11) each with a substantially homogeneous magnetic field are generated outside the envelope, the homogeneity of each of the first and second working volumes being sufficient to perform a NMR experiment on a sample in the working volume.

Abstract: Disclosed are a system, apparatus, and method for determining a physiologic characteristic of a body lumen that include determining, at one or more selected pressures, the volume of incompressible medium infused into a balloon 54 of catheter 24 while the balloon is placed in each of (a) a lumen having a predetermined, fixed diameter and (b) a desired location of a body lumen having an unknown diameter. In certain variations, the physiologic characteristic (e.g., diameter, cross-sectional area) is determined by calculating the difference in the volume of infused medium between (a) and (b) at at least one static pressure. Other physiologic characteristics (e.g., compliance) are determined by calculating the difference in infused medium for (b) at at least two static pressures.

Abstract: An apparatus for magnetic resonance imaging, comprises a first magnet for generating a first magnetic field and a second magnet for generating a second magnetic field, dissimilar to the first magnetic field, the second magnet being spaced apart from the first magnet. The apparatus is arranged such that the first and second magnets cooperate to generate a substantially homogeneous magnetic field defining a working region wherein the first and second magnetic fields are arranged asymmetrically with respect to the working region, and wherein at least part of the working region is positioned within the first magnet or between the first and second magnets.

Abstract: A magnet assembly comprising first and second sets of coils (1, 2) for generating respective magnetic fields, wherein the coils are constructed and arranged such that under working conditions, a first homogeneous region (3) can be generated within the envelope defined by the magnet 10 assembly and a second homogeneous region (4) can be generated outside the envelope, the resultant magnetic field in each region being sufficiently homogeneous to enable a NMR process to be performed on an object in the region.

Abstract: An imaging and catheter steering assembly comprising a magnetic field generating assembly (1-6) operable in a first mode to generate a first magnetic field in a working volume (7) located outside the assembly, the first magnetic field being suitable for use in a catheter, steering procedure. In a second mode the assembly (1-6) generates a second, static magnetic field in the working volume (7) suitable for conducting a magnetic resonance imaging process (MRI), the second magnetic field being more uniform in the working volume than the first magnetic field. A catheter (67) has a magnetic seed attached whose orientation, and hence the steering direction of the catheter, is determined by interaction with the first magnetic field.

Abstract: An expandable dilation catheter advantageously useful to deliver and orient an endovascular prosthesis with respect to a target body passageway. The catheter comprises a first tubular member disposed in a proximal portion of the portion of the catheter and a second tubular member disposed in a distal portion of the catheter. The first tubular member and the second tubular member are in a spaced relationship with respect to one another. An expandable member (e.g., a ballon) is disposed distally of the second tubular member. A first lumen and a second lumen disposed in each of the first tubular member and in the second tubular member. The first lumen is in communication with an interior of the expandable member to function as an inflation lumen and the second lumen serves to receive a first guidewire. The first tubular member and second tubular member are interconnected by a coupling member.

Abstract: Placement and non-surgical removal of a ureteral stent is accomplished by suspending a ferromagnetic bead from an indwelling stent. The bead is suspended by a flaccid tether that reduces the likelihood of patient irritation when a shortened stent is used. The bead, tether, and stent assembly are advanced into the patient as a unit via a conventional cystoscope. A magnet-tipped catheter is employed to engage the bead in the bladder and permit removal of the connected stent as the catheter is withdrawn.

Abstract: An apparatus and method for causing necrosis of tissue and specifically intended for thermal ablation of the uterine cavity to cauterizing the endometrial tissue. The apparatus includes a liquid-tight, liquid filled system having a distal flexible member; a proximal flexible member; and a catheter joining and providing a liquid path between these distal and proximal members. The apparatus further includes a pressurizable pneumatic chamber into which the proximal flexible member is inserted and a means to controllably heat the contents of the pneumatic chamber. The system operates to: first withdraw substantially all of the liquid into the proximal flexible member contained within the pressurizable pneumatic chamber; second to heat this liquid to a temperature such that it can cause tissue necrosis; and third to force the heated liquid from the proximal flexible member into the distal flexible member where it is maintained for a predetermined time and at a predetermined pressure.

Abstract: An apparatus and method for causing necrosis of tissue and specifically intended for thermal ablation of the uterine cavity to cauterizing the endometrial tissue. The apparatus includes a liquid-tight, liquid filled system having a distal flexible member; a proximal flexible member; and a catheter joining and providing a liquid path between these distal and proximal members. The apparatus further includes a pressurizable pneumatic chamber into which the proximal flexible member is inserted and a means to controllably heat the contents of the pneumatic chamber. The system operates to: first withdraw substantially all of the liquid into the proximal flexible member contained within the pressurizable pneumatic chamber; second to heat this liquid to a temperature such that it can cause tissue necrosis; and third to force the heated liquid from the proximal flexible member into the distal flexible member where it is maintained for a predetermined time and at a predetermined pressure.

Abstract: Placement and non-surgical removal of a ureteral stent is accomplished by suspending a ferromagnetic bead from an indwelling stent The bead is suspended by a flaccid tether that reduces the likelihood of patient irritation when a shortened stent is used. The bead, tether, and stent assembly are advanced into the patient as a unit via a conventional cystoscope. A magnet-tipped catheter is employed to engage the bead in the bladder and permit removal of the connected stent as the catheter is withdrawn.

Abstract: Apparatus to remove tissue. The apparatus has an outer cannula and an inner cannula received within the outer cannula. The cannula are longitudinally movable relative to each other. There is an abutment at the end of one cannula to contact the other cannula. A drive permits advancing of the other cannula to contact the abutment whereby tissue between the other cannula and the abutment is removed. The invention finds particular application in removable of lens tissue from the eye of a human or other animal.