Abstract: Systems and methods for controlling the power supplied to an electrosurgical probe. The systems and methods may be used to monitor electrode-tissue contact, adjust power in response to a loss of contact, and apply power in such a manner that charring, coagulum formation and tissue popping are less likely to occur.

Abstract: An expandable tubular reinforcing member used for body lumens such as blood vessels, the reinforcing member being formed of a continuous elongated helical element comprised of spaced undulating portions forming end loop portions and including a plurality of curvilinear connector elements extending between and interconnecting at least some of the adjacent undulating portions of the helical element over its length.

Abstract: A method for profiling an infusion of a medicament into the wall of an artery involves inserting an intravascular ultrasound device into the artery and advancing it to the location of the infusion. A pullback device withdraws the intravascular ultrasound device from the artery, pausing at predetermined axial sites along the location of the infiltrated medicament to image the infusion profile at each site. A computer then compiles the individual site profiles to produce three dimensional images indicating the extent of infiltration of the medicament into the tissue surrounding the artery.

Abstract: A wire station is disclosed for securing and managing multiple wire members used in a catheter system. The wire management system includes means for securing the proximal portion of two wire members in a spatially separate arrangement. The wire station of the present invention additionally provides a physician with the flexibility of either directly attaching the wire station of the present invention to the catheter system directly, or positioning the wire station at a remote location.

Abstract: Segmented articulatable stent of open structure comprised of end-connected struts making up the segments with angular interconnects between segments.

Abstract: A medical device shaft for connection with a handle and for insertion within a body includes an elongated, deflectable shaft having a proximal shaft portion, an intermediate shaft portion, and a distal shaft portion. The elongated, deflectable shaft includes a transition in stiffness from the proximal shaft portion to the distal shaft portion. In a preferred implementation, the shaft includes a plurality of slits that extend perpendicular to a longitudinal axis of the shaft. Varying at least one of the number of slits, the location of slits, the frequency of slits, the orientation of the slits, the size of the slits, and the depth of the slits varies the transition of stiffness.

Abstract: A stent and method of its use, the stent in its expanded configuration, exhibiting varying outward radial force along its length. In use, the expanded stent is of a tapered configuration which provides greater force in vessel regions requiring greater force and less force in regions requiring less. In particular the stent is useful in the ostium regions and at areas of bifurcation in vessels. Varying force over the length of the stent is achieved by varying the number of elements, the density of elements, the thickness of the elements making up the stent body, and maintaining a substantially metal to artery ratio in the expanded stent over its length.

Abstract: An apparatus for steering a guidewire and for connecting the guidewire to an extension guidewire. The apparatus includes a steering device for gripping an exterior of the guidewire, the steering device defining a passageway therein through which the guidewire may pass; and a connecting device for connecting the guidewire to the extension guidewire. The connecting device is configured for mating with the steering device to form an integral unit. The invention further includes a method of inserting a guidewire in a body and connecting the guidewire to an extension guidewire.

Abstract: A driven catheter system (2) includes broadly a driven catheter assembly (6) coupled to a control unit (4). The driven catheter assembly includes a motor drive unit (8) and a catheter assembly (10) mounted thereto. The catheter assembly includes a rotational and translational drive coupling (26) and a catheter (14) extending therefrom. The catheter includes a sheath (16) and a core (18) slidably housed within the sheath. The drive coupling includes an elongate rotary drive element (36), defining a first longitudinal drive path, mounted for rotation about a longitudinal axis (42). A termination element (44) is mounted to the proximal end of the core and slides along the first longitudinal drive path but rotates with the rotary drive element. A bearing (46) has an inner race (48) secured to the termination member and an outer race (50) coupled to the longitudinal drive element (54, 62) of a longitudinal driver (56).

Abstract: An ultrasonic imaging catheter is used to generate a three-dimensional image of an organ having a relatively large cavity, such as, e.g., a heart. The catheter includes an elongate catheter body having an acoustic window formed at its distal end. The catheter further includes an imaging core, which includes a drive cable with a distally mounted ultrasonic transducer. The transducer is disposed in the acoustic window and is rotationally and longitudinally translatable relative thereto, providing the catheter with longitudinal scanning capability. The catheter further includes a pull wire, which is connected to the distal end of the catheter body, such that longitudinal displacement of the pull wire causes the acoustic window to bend into a known and repeatable arc. The catheter can then be operated to generate a longitudinal scan of the organ through the arc, i.e.

Abstract: An ablation burr has a body provided with an inner circumferential rim and an outer circumferential rim that are concentric and spaced longitudinally by a selected distance along the length of the burr. The outer circumferential rim has a generally smooth convex outer surface that reduces damage to a vessel wall or stent. A leading surface of the burr extends between the inner and outer circumferential rims in a substantially uniform, concave manner. An abrasive, for example, diamond grit, is provided on the leading surface. The burr is selectively rotated by a drive shaft, causing the abrasive leading surface of the burr to ablate unwanted deposits. If desired, a wire extends co-axially through the body such that a distal end of the wire extends out of the distal end of the burr. An abrasive tip may be coupled to the distal end of the wire, and is selectively rotated, to ablate unwanted deposits.

Abstract: A deflectable interstitial ablation device includes an elongated housing, an electrode mounted within the elongated housing, a driver coupled to the electrode, an imaging device integrally mounted within the elongated housing and a deflection system disposed within the elongated housing. The elongated housing has a proximal end, a distal end, and a deflectable segment. The electrode is deployable from a first position within the elongated housing to a second position a predetermined distance beyond the distal end of the elongated housing. The electrode further has a flexible portion capable of deflecting with the deflectable segment of the elongated housing, and can be deployed by the driver with a sufficient force such that penetration of the urethral wall occurs in a single motion. The imaging device further has a flexible portion capable of deflecting with the deflectable segment of the elongated housing.

Abstract: A full-thickness resection system comprises a flexible endoscope and a stapling mechanism, wherein the endoscope is slidably received through at least a portion of the stapling mechanism. The stapling mechanism comprises an anvil and a stapling head mounted to the anvil so that the anvil and the stapling head are moveable with respect to one another between a tissue receiving position and a stapling position and wherein a gap formed between the stapling head and the anvil is larger in the tissue receiving position than it is in the stapling position. A position adjusting mechanism is provided for moving the anvil and the stapling head between the tissue receiving and stapling positions and a staple firing mechanism sequentially fires a plurality of staples from the stapling head across the gap against the anvil and through any tissue received in the gap and a knife cuts a portion of tissue received within the gap.

Abstract: A radially expandable stent comprising a plurality of spaced band-like elements and intersecting links is disclosed. The band-like elements have a generally serpentine configuration to provide continuous waves of generally sinusoidal character to each band-like element. The waves are characterized by a plurality of peaks and troughs taking a generally longitudinal direction along the cylinder such that the waves in the band-like elements open as the stent is expanded from a first diameter to a second diameter. The intersecting links are substantially U-shaped and terminate in first and second shanks. The first shank of a link emanates from a region between a peak and trough on a band-like element and the second shank of the link emanates from a region between a peak and trough on an adjacent band-like element.

Abstract: A stent delivery system which has a catheter including an inflatable portion. A stent being disposed about the inflatable portion of the catheter, the stent having a contracted state and an expanded state. A pair of stent retaining sleeves which are partially composed of PTFE, each sleeve having a first end portion overlying a respective end of the stent, each sleeve having a second end portion respectively attached to the catheter, the sleeves retaining the stent to the catheter when the stent is in the contracted state, the stent being freed from the sleeves when the stent is placed in the expanded state. The sleeves being placed on the stent by heat shrinking. The inflatable portion of the balloon optionally having stepped compliant characteristics.

Abstract: A multifilar flexible rotary shaft includes a plurality of individual filaments which are not wound around each other or around a central core, a loose ensemble of filaments. The input ends of each filament are coupled to each other and the output ends of each filament are coupled to each other. Preferably all of the filaments are identical. A loose ensemble of N filaments can transmit N times the torque of a single filament, and will have N times the torsional stiffness of a single filament, while retaining the minimum radius of operation of a single filament. Since a loose ensemble of filaments does not have any appreciable contact forces among the filaments (because they are not forcibly twisted together), there is no appreciable internal friction or hysteresis. In order to appreciably eliminate all the hysteresis in such an ensemble of filaments, the filaments should be no more than loosely twisted together, if at all.

Abstract: A medical retrieval device for retrieving foreign objects from a patient and the method of constructing the device are disclosed. The device incorporates a wire cable composed of a precursor alloy to a superelastic material to improve durability of the device. Because precursor alloys exhibit a linear stress-strain relationship and a yield point associated with a relatively high stress level, the device transfers greater stresses before experiencing deformation. Thus, greater crushing forces can be achieved using a device of this type. These crushing forces may be needed when the foreign object is too large to remove intact. This property also facilitates the device in dilating ducts to retrieve foreign objects. Using the precursor alloy additionally eliminates the need for heat treatment of the cables used in constructing the device. A retrieval device made of precursor alloy cable also is less susceptible to permanent deformation and unwinding during use.

Abstract: Rotating element catheters and catheter assemblies employ clutch assemblies for preventing rotational energy from being transmitted from a motor drive unit to the catheter element under defined circumstances. The catheter assembly includes an elongate member in which there is disposed a rotatable catheter drive cable. The catheter drive cable may have an operative element, e.g., an ultrasonic transducer or an artherectomy blade, distally mounted thereon for providing diagnostic or therapeutic functions to the physician. To control the rotation of the catheter drive shaft, the clutch assembly is configured such that the catheter drive shaft is operated in a drive mode (i.e., it is allowed to rotate) and in a release mode (i.e., it is prevented from rotating).

Abstract: An endoscope having a guide wire with an x-ray transparent window allows x-rays from an x-ray source to pass therethrough to reach the desired site. Preferably, the guide wire and x-ray catheter, which contains the x-ray source, have positioning flags or markers to aid alignment of the x-ray source with the x-ray transparent window of the guide wire.

Abstract: An ultrasound transducer having an acoustic backing layer made of an aerogel material is disclosed. The ultrasound transducer comprises an acoustic element for transmitting and receiving ultrasound waves. An aerogel acoustic backing layer is bonded to the back side of the acoustic element. A matching layer may be attached to the front side of the acoustic element. The ultrasound transducer may be electrically connected using electrodes directly connected to the acoustic element. Alternatively, the aerogel acoustic backing may be coated with a metalized layer or doped so that it is electrically conductive. Then, the electrodes may be connected directly to the aerogel acoustic backing.