Abstract: An improved catheter system having an ultrasonic imaging transducer coupled to a drive cable disposed within a lumen of a flexible tubular catheter body. An improvement including a reconfiguration of the ferrites in the hub assembly, such that the need for the gap between the ferrites is removed. A strain relief member is provided to increase the strength of the electrical transmission lines to enable them to withstand the tensile forces caused by either flushing and/or pull-back operations. A device which allows the electrical transmission lines to extend their length when placed in tension may also be employed to provide strain relief to the electrical transmission lines. Another improvement includes a counter-wound coil structure, which may either expand or contract as the drive cable is being rotated to strengthen the drive cable. The distal tip of the catheter body may be redesigned to provide a lumen which allows for the release of flushing fluids through a distal port in the guidewire lumen.

Abstract: An improved catheter system having an ultrasonic imaging transducer coupled to a drive cable disposed within a lumen of a flexible tubular catheter body. An improvement including a reconfiguration of the ferrites in the hub assembly, such that the need for the gap between the ferrites is removed. A strain relief member is provided to increase the strength of the electrical transmission lines to enable them to withstand the tensile forces caused by either flushing and/or pull-back operations. A device which allows the electrical transmission lines to extend their length when placed in tension may also be employed to provide strain relief to the electrical transmission lines. Another improvement includes a counter-wound coil structure, which may either expand or contract as the drive cable is being rotated to strengthen the drive cable. The distal tip of the catheter body may be redesigned to provide a lumen which allows for the release of flushing fluids through a distal port in the guidewire lumen.

Abstract: An improved catheter system having an ultrasonic imaging transducer coupled to a drive cable disposed within a lumen of a flexible tubular catheter body. The distal tip of the catheter body may be redesigned to provide a lumen which allows for the release of flushing fluids through a distal port in the guidewire lumen. The catheter includes a wedge disposed between a primary lumen and a guidewire lumen and a wedge lumen formed in the wedge allows communication between the primary lumen and the guidewire lumen.

Abstract: A diagnostic catheter using a vacuum for tissue positioning is provided. A method for analyzing tissue in accordance with one embodiment of the present invention includes inserting a catheter having a sensor at its distal end into the body of a patient. Applying suction through the catheter to draw tissue into a predetermined sensing position for the sensor and then analyzing the tissue with the sensor. An apparatus for testing tissue within the body of a patient in accordance with an alternative embodiment of the present invention includes a catheter having a first end and a second end, the first end having an orifice and also having a sensor, the orifice in fluid communication with a vacuum channel.

Abstract: A method and system for indicating the position and orientation of a scan plane relative to a patient is provided. The image as presented on a display is oriented in accordance with the orientation of a transducer. The orientation may provide for displaying an image where the transducer is not in a transducer up or transducer down position, but is rotated away from vertical of the display. Alternatively or additionally, a two or three-dimensional graphical generic representation is provided with a scan plane indicated as a polygon or image rendering within a generic representation to show relative positioning of the scan plane with respect to the patient.

Abstract: A treatment catheter (10) carries an elongated ultrasonic emitter (20) extending in the lengthwise direction of the catheter. The array is flexible in all directions transverse to the lengthwise direction. The treatment catheter is inserted into a chamber of the heart and brought to a desired configuration such as a substantially closed loop. The treatment catheter is then biased into engagement with the wall of the heart by an expansible balloon (62) or other expansible structure, which may be carried on a separate stabilizer catheter (60). While the treatment catheter is engaged with the heart wall, the array is actuated to ablate tissue along a path having a shape corresponding to the configuration of the treatment catheter.

Abstract: A needle device for penetrating body tissues while substantially reducing the risk of damage to blood vessels and body organs by using visual control of the operative tip during insertion and the procedure, is disclosed herein. The needle device of the present invention has a large and diverse applicability to a number of medical procedures by enabling internal visual inspection of body tissues and cavities during treatment without open surgery or supplemental penetrating or visualization devices.

Abstract: A medical device assembly and method provides an ultrasound transducer mounted onto a catheter shaft. The ultrasound transducer is mounted such that there is a radial separation between the transducer and the underlying catheter shaft. The transducer is mounted on support structures which do not bridge the gap between the transducer and delivery member. The location of the support structures provides for an “airbacked” transducer that is very efficient and prevents heat build-up in the materials in contact therewith.

Abstract: A rotationally vibrating imaging catheter and method of utilization has an array of ultrasound transducers and an actuator along with signal processing, display, and power subsystems. The actuator of the preferred embodiment is a solid-state nitinol actuator. The actuator causes the array to oscillate such that the tip of the catheter may be rotated through an angle equal to or less than 360 degrees. The tip is then capable of rotating back the same amount. This action is repeated until the desired imaging information is acquired. The rotationally vibrating catheter produces more imaging points than a non-rotating imaging catheter and eliminates areas of missing information in the reconstructed image. Rotationally vibrating catheters offer higher image resolution than stationary array catheters and greater flexibility and lower costs than mechanically rotating imaging catheters.

Abstract: The present invention is an apparatus for treating a selected patient tissue or organ region, at the surface of such region. The apparatus has an accessing tool for accessing the patient region, the tool having a distal end, and a proximal end at which the tool can be manipulated to place the distal end adjacent to the patient region. The apparatus also has a probe carried on the distal end and defining a contact surface that may be urged against the patient region thereby creating contact pressure. A pressure transducer is operatively coupled to the probe and is capable of producing a measurable response to the contact pressure. A monitoring device is operatively connected to the pressure transducer, for determining the contact pressure. An effector is operatively disposed on the probe for producing a given effect on the patient region when the effector is activated, and an activator operatively connected to the effector, by which the effector can be activated.

Abstract: The preferred embodiments described herein provide a medical diagnostic ultrasound catheter with a tip portion carrying an ultrasound transducer. The tip portion comprises a first portion that is in the acoustic path of the ultrasound transducer, and a second portion that is outside the acoustic path of the ultrasound transducer. The first and second portions comprise different acoustic and mechanical properties. For example, the mechanical properties of the second portion can give the catheter tip sufficient durability to withstand normal use without bowing, while the acoustic properties of the first portion can give the catheter tip desired acoustic properties. This may be especially important for small diameter catheters (e.g., maximum cross-sectional dimensions less than or equal to about 10 French or 8 French) where the stiffness of the catheter tip is reduced.

Abstract: A diagnostic and/or therapeutic catheter having a plurality of ultrasound transducers. In a first embodiment, the center frequencies of the second and third transducers may be substantially equal to a fundamental harmonic and a second harmonic, respectively, of ultrasound waves created by the first transducer. In second embodiment, the second transducer transmits waves with a center frequency substantially equal to the center frequency of the first transducer. In third embodiment, the second transducer has a center frequency that differs from the center frequency of the first transducer and the center frequency of the third transducer may be substantially equal to a difference between the fundamental harmonic of the ultrasound waves transmitted by the first transducer and a fundamental harmonic of ultrasound waves produced by the second transducer.

Abstract: A vascular catheter system comprises a catheter body having a proximal portion with a proximal end, a distal end and work lumen therebetween and a distal portion with a proximal end, a distal end, a work lumen therebetween and a guidewire lumen distal to the work lumen. A first connector is secured to the distal end of the proximal portion and a second connector is secured to the proximal end of the distal portion. The first and second connectors can be selectively connected to each other to join the work lumens of the proximal and distal portions together.

Abstract: A method of mounting a transducer to a driveshaft which eliminates the need for a transducer housing, the improved method directly attaches the transducer to a rigid distal tip of a driveshaft which is part of a rotatable imaging core of a catheter assembly. The method contemplates heat treating the distal tip of the driveshaft to make it rigid, machining the distal tip to be dimensioned to hold the transducer, and attaching the transducer to the distal tip by clamping, crimping, or an adhesive.

Abstract: The present invention provides a method of recording and displaying in context of an image a location of at least one point-of-interest in a body during an intra-body medical procedure. The method includes establishing locations of the body, an imaging instrument and a location implement included within a catheter, and allows at least one point-of-interest to be displayed in the context of an image of the portion of the body, even in cases in which a relative location of the body and the imaging instrument are changed.

Abstract: A method and system for imaging an artery contained in an arterial tree. A microprocessor generates a three-dimensional reconstruction of the arterial tree from two or more angiographic images obtained from different perspectives. The orientation of the axis of the artery in the arterial tree is then determined, and a perspective of the artery perpendicular to the axis of the artery is determined. A three dimensional reconstruction of the artery from angiographic images obtained from the determined perspective is then generated.

Abstract: A method and apparatus for remotely monitoring the location of an interventional medical device (IMD) using ultrasonic signals. Both the proximity and alignment of the IMD are calculated from ultrasound signals reflected off the tissue surface. The inclusion of an offset between the distal end of the IMD and the ultrasound transducer enables accurate position and alignment monitoring of when the IMD is in contact with, or very close to, the tissue surface. The timing of the reflected signal is used to measure proximity or contact. A comparison of the strength between multiple reflected signals is used to measure the alignment of the IMD in 3D space or perpendicularity to a given surface. The present invention may be used as a location indicator within a wide variety of IMDs, and in a wide variety of medical procedures.

Abstract: A parametric imaging ultrasound catheter apparatus is capable of obtaining parametric images of the surrounding insonated environment. Parametric imaging is defined as the imaging of quantifiable “parameters” which of visible two-, three-, fourth-dimensional or non-visible higher-dimensional temporal physiologic events. Visible motion is a fourth-dimensional event and includes surrogate features of cardiac muscle contraction, wall motion, valve leaflet motion, etc. Non-visible motion is a higher-dimensional event and includes slow non-visible events (i.e., remodeling, transformation, aging, healing, etc.) or fast non-visible events (i.e., heat, electricity, strain, compliance, perfusion, etc.). An ultrasound catheter with parametric imaging capability can obtain dynamic digital or digitized information from the surrounding environment and display information features or quanta as a static or dynamic geometric figures from which discrete or gross quantifiable information can be obtained.

Abstract: Apparatus for acquiring in vivo images of a site of interest within the internal organs of a body. The apparatus includes an elongate, flexible catheter. The catheter is introducible into the body and has a first end that remains external to the body and a second and positionable adjacent the site of interest. A movable scanning unit having at least one sensor for acquiring images is housed adjacent the second end of the catheter. There is a drive mechanism to control movement of the movable scanning unit from the first external end of the catheter to acquire multiple images of the site of interest. The drive mechanism has a control element extending the length of the catheter lumen adapted for linear movement within the lumen to generate linear or rotational movement of the scanning unit.

Abstract: Systems and methods for generating Magnetic Resonance Imaging (MRI) elastographs of a region in a body are provided. A catheter, in accordance with one embodiment, comprises an elongated member, an acoustic transducer positioned near a distal end of the elongated member, and a Radio Frequency (RF) coil adjacent to the acoustic transducer. To generate an MRI elastograph of a region in a body, the acoustic transducer and the RF coil of the catheter are positioned at the desired region in the body. The acoustic transducer emits acoustic waves in the region of the body, and the RF coil detects RF signals emitted within the region of the body. The detected RF signals are outputted to an MRI receiver to generate the MRI elastograph of the region in the body.

Abstract: The catheter is constructred of a substantially cylindrical tube, longitudinally subdivided in multiple parallel lumens for wires, available to introduce drives having a distal end with a variable curving, and of fiberoptics for the delivery of energy as laser emission, or different ablation devices. The amagnetic distal electrodes permit the high-resolution mapping of multiple monophasic action potentials just at the arrthythmogenic foci themselves, the magneto cardiographic localization of the catheter and the possible modification of the electrophysiological substrate with the delivery of energy as laser emission. The catheter can be intracardiacally manipulated in the patient with a very high accuracy by exploiting the variability of the curving of the distal end and the sliding thereof into preformed external sheaths, for fitting at the best the threedimensional coordinates thereof with those of the arrhythmogenic substrate, non-invasively predetermined by magnetocardiographic imaging.

Abstract: A transverse mode ultrasonic probe is provided which creates a cavitation area along its longitudinal length, increasing the working surface of the probe. Accessory sheaths are also provided for use with the probe to enable a user to select from features most suited to an individual medical procedure. The sheaths provide acoustic enhancing and aspiration enhancing properties, and/or can be used as surgical tools or as medical access devices, protecting tissue from physical contact with the probe.

Abstract: A method of treating a target region in a body lumen, said method comprising: directing a uniform dose of ultrasonic energy from an interior of the lumen radially outward over a treatment length of the lumen, wherein the dosage of ultrasonic energy received at any one point along the length varies by no more than plus or minus 6 decibels from that received at any other point along the length.

Abstract: An improved system and method to provide visualization of implantable leads, catheters, or other implantable devices is disclosed. According to the invention, an unmodified guiding device such as a stylet or guidewire is frictionally coupled to a vibration device. This guiding device is further inserted into the device to be visualized. When activated, the vibration device transfers longitudinal waves to the guiding device, which, in turn, transfers the waves to the device that is to be visualized. These waves are detected by an imaging device, which then generates a Doppler image of the implantable device. According to one aspect of the invention, the vibration device includes a piezoelectric actuator. According to another aspect of the invention, the frequency of the waves that are transferred by the vibration device is selectable.

Abstract: A method for ultrasound medical treatment of a patient. An end effector is obtained having an ultrasound medical-treatment transducer assembly. The assembly is aimed to focus ultrasound energy at a desired focal zone of patient tissue. The assembly is activated to emit ultrasound energy sufficient to achieve a temperature increase in the patient tissue essentially without medically affecting the patient tissue. An actual focal zone of patient tissue having a temperature increase is detected from reflected ultrasound energy. Any error between the desired focal zone and the actual focal zone is corrected for. The patient tissue is medically treated with ultrasound using the assembly. In one example, the ultrasound medical-treatment transducer assembly is an ultrasound imaging and medical-treatment transducer assembly. In one variation, the end effector is inserted into the patient. In another variation, the end effector remains outside the patient.

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 artherctomy 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). The clutch assembly includes a driver member and a driven member, one of which is magnetic and the other of which is ferrous. The magnetic and ferrous members are arranged in relation to each other, e.g.

Abstract: A medical imaging system with a base unit including an electronic display, and a remote imaging transducer connected to the display unit via a flexible cable. The cable includes a number of signal transmission lines, each of which includes a twisted pair of conductors for digital differential signal lines. Each conductor is connected at a first end to the transducer, and at a second end to the base unit. The signal transmission lines may be wrapped about a core, which may be an optical conduit communicating with a light source at the base unit.

Abstract: An ultrasound medical treatment system includes an end effector insertable into a patient. The end effector includes a tissue-retaining device. The tissue-retaining device includes a first tissue-retaining member having an ultrasound medical-treatment transducer and includes a second tissue-retaining member. The first and second tissue-retaining members are operatively connected together to retain patient tissue between the first and second tissue-retaining members and to release patient tissue so retained. In one example, the second tissue-retaining member has an ultrasound reflector. In the same or a different example, the ultrasound medical-treatment transducer is an ultrasound imaging and medical-treatment transducer.

Abstract: A method for ultrasound medical treatment of a patient. An end effector is obtained having an ultrasound medical-treatment transducer assembly. The end effector is inserted into the patient. The end effector is guided within the patient to a lung of the patient. A lesion is identified on or in the lung for medical treatment. The transducer assembly is positioned on or in the lesion. The lesion is medically treated with ultrasound using the transducer assembly. In one example, the ultrasound medical-treatment transducer assembly is an ultrasound imaging and medical-treatment transducer assembly, and the lesion is identified at least in part from ultrasound imaging using the transducer assembly.

Abstract: One embodiment of an ultrasound medical treatment system includes an end effector and at least three receivers. The end effector has a transducer assembly including a transducer having at least one transducer element adapted for emitting medical-treatment ultrasound waves and for emitting mechanical waves. The receivers are spaced apart from the transducer assembly, and the receivers are adapted to receive the emitted mechanical waves for use in locating the position of the transducer assembly. Another embodiment of an ultrasound medical treatment system includes an end effector and at least three receivers. The end effector has an ultrasound medical-treatment transducer assembly and has a transponder. The transponder is adapted to emit waves, and the waves include electromagnetic waves or mechanical waves or both. The receivers are spaced apart from the transducer assembly, and the receivers are adapted to receive the emitted waves for use in locating the position of the transponder.

Abstract: An ultrasound imaging system comprising an ultrasound transducer, an ultrasound imaging device incompatible with the transducer and a transducer adapter including an adapter-transducer connector to connect to a transducer connector of the ultrasound transducer, a system connector to connect to an ultrasound connector of the ultrasound imaging device, and an interface to provide compatible electrical information signals to/from the ultrasound transducer from/to the ultrasound imaging device via the connectors.

Abstract: A catheter assembly includes an elongate catheter body having a proximal end and a distal end with a drive cable disposed therein, the drive cable having a proximal end and a distal end, and rotatable relative to the catheter body. A first electromagnetic element is disposed proximate the distal end of the catheter, and a second electro-magnetic element disposed proximate the distal end of the drive cable and in electrical communication with an operative element mounted at the end of the drive cable, the first and second electromagnetic elements forming an inductive coupler. The catheter assembly can include various other distal operative elements, which are in communication with corresponding proximal operative elements via transmission lines embedded within the wall of the catheter body.

Abstract: An improved catheter system having an ultrasonic imaging transducer coupled to a drive cable disposed within a lumen of a flexible tubular catheter body. An improvement including a reconfiguration of the ferrites in the hub assembly, such that the need for the gap between the ferrites is removed. A strain relief member is provide to increase the strength of the electrical transmission lines to enable them to withstand the tensile forces caused by either flushing and/or pull-back operations. A device which allows the electrical transmission lines to extend their length when placed in tension may also be employed to provide strain relief to the electrical transmission lines. Another improvement includes a counter-wound coil structure, which may either expand or contract as the drive cable is being rotated to strengthen the drive cable. The distal tip of the catheter body may be redesigned to provide a lumen which allows for the release of flushing fluids through a distal port in the guidewire lumen.

Abstract: An ultrasonic endoscope has a bending portion, an ultrasonic probe, and a flexible circuit board. The bending portion, connected to the point of a flexible tube, bends along two predetermined bending-directions perpendicular to each other, by remote control. The ultrasonic probe has a plurality of ultrasonic wave vibrators, which are arranged circumferentially, and send ultrasonic waves radially and receive echoes of the ultrasonic waves. The flexible circuit board, which transmits signals associated with the ultrasonic waves and the echoes, is constructed of a plurality of flexible circuit board strips in the bending portion so as to allow a bending motion. The plurality of flexible circuit board strips are arranged such that a bending-resistance to the bending motion occurs symmetrically with respect to a primary central line, corresponding to one of the two bending-directions.

Abstract: An ultrasonic endoscope has a bending portion, an ultrasonic probe, and a flexible circuit board. The bending portion, connected to the point of a flexible tube, bends by remote control. The ultrasonic probe has a plurality of ultrasonic wave vibrators, which are arranged circumferentially, and send ultrasonic waves radially and receive echoes of the ultrasonic waves. The flexible circuit board, which transmits signals associated with the ultrasonic waves and the echoes, is constructed of a plurality of flexible circuit board strips in the bending portion so as to allow a bending motion. The plurality of ultrasonic wave coaxial lines, which are provided in the flexible tube to form an ultrasonic wave coaxial cable and are connected to the plurality of flexible circuit board strips, are loose and flexible in a given range.

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: A catheter useful for improving blood flow to a patient's heart has an elongated catheter body with a proximal end and a distal end. The elongated catheter body defines a catheter lumen. The elongated catheter body has an introducer distal portion with a tissue piercing distal end. An ultrasound transducer is positioned in the introducer distal portion.

Abstract: An ultrasonic endoscope has a bending portion, an ultrasonic probe, and a flexible circuit board. The bending portion, connected to the point of a flexible tube, bends along two predetermined bending-directions perpendicular to each other, by remote control. The ultrasonic probe has a plurality of ultrasonic wave vibrators, which are arranged circumferentially, and send ultrasonic waves radially and receive echoes of the ultrasonic waves. The flexible circuit board, which transmits signals associated with the ultrasonic waves and the echoes, is constructed of a plurality of flexible circuit board strips in the bending portion so as to allow a bending motion. The plurality of flexible circuit board strips is durable for the bending motion of said bending portion.

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: A vascular catheter system comprises a catheter body having a proximal and distal portion and a single common lumen therebetween. The catheter body includes a first connector secured to the distal end of the proximal portion and a second connector secured to the proximal end of the distal portion. The connectors can be selectively connected to each other to join the lumens of the proximal and distal portions together in a continuous, axially fixed relationship. Disposed within the lumens, when the proximal and distal portions are joined together, is a drive cable. The drive cable may be movably, rotatable about its own longitudinal axis and carries at its distal end, a work element, which is typically an ultrasonic imaging transducer or interventional device. The lumen carrying the cable will be sufficiently large along a proximal portion to permit preferential collapse of the cable should rotation of the distal end become impeded.

Abstract: An improved catheter system having an ultrasonic imaging transducer coupled to a drive cable disposed within a lumen of a flexible tubular catheter body. An improvement including a reconfiguration of the ferrites in the hub assembly, such that the need for the gap between the ferrites is removed. A strain relief member is provide to increase the strength of the electrical transmission lines to enable them to withstand the tensile forces caused by either flushing and/or pull-back operations. A device which allows the electrical transmission lines to extend their length when placed in tension may also be employed to provide strain relief to the electrical transmission lines. Another improvement includes a counter-wound coil structure, which may either expand or contract as the drive cable is being rotated to strengthen the drive cable. The distal tip of the catheter body may be redesigned to provide a lumen which allows for the release of flushing fluids through a distal port in the guidewire lumen.

Abstract: An ultrasound transducer array (408) includes at least one transducer element (412) having a first (604) and second (606) portions separated by an acoustical discontinuity (520). The first portion (604) has the desired length to form a half-wave k31 resonance, while the second portion (606) has a resonant length for an undesired very low frequency out-of-band k31 resonance. The thickness of the transducer element (412) is designed for k33 half-resonance. Given the design, the transducer element (412) can operate and provide for both forward-looking (514) and side looking (512) elevation apertures. A method is also disclosed for using the disclosed ultrasound transducer (412) in ultrasound imaging.

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). The clutch assembly includes a driver member comprising a first cylindrical body, and a driven member comprising a second cylindrical body in a concentric relationship with the first cylindrical body.

Abstract: A vascular catheter system comprises a catheter body having a proximal and distal portion and a single common lumen therebetween. The catheter body includes a first connector secured to the distal end of the proximal portion and a second connector secured to the proximal end of the distal portion. The connectors can be selectively connected to each other to join the lumens of the proximal and distal portions together in a continuous, axially fixed relationship. Disposed within the lumens, when the proximal and distal portions are joined together, is a drive cable. The drive cable may be movably, rotatable about its own longitudinal axis and carries at its distal end, a work element, which is typically an ultrasonic imaging transducer or interventional device. The lumen carrying the cable will be sufficiently large along a proximal portion to permit preferential collapse of the cable should rotation of the distal end become impeded.

Abstract: The present invention provides ultrasound imaging catheters, systems and methods for their use which will be particularly useful to monitor the positioning of ablation catheters. In one embodiment, an imaging catheter (10) includes a catheter body (11) having a distal end (12), a proximal end (14) and a longitudinal axis (16). A transducer (20) is rotatably coupled to the distal end. The transducer has an axis of rotation (24) that is at a non-zero angle relative to the catheter body longitudinal axis. Such a configuration provides an exemplary side-looking imaging catheter.

Abstract: A catheter including an elongated body member, an ultrasound transducer located on the elongated body member, and dampening means for forming an ultrasound dampening region adjacent to a portion of the ultrasound transducer, is disclosed. The ultrasound transducer is configured to transmit or receive an ultrasound signal. The ultrasound dampening region is configured to improve uniformity of said ultrasound signal in three-dimensional space. Preferably, the dampening means includes air or a material containing air.

Abstract: An improved catheter system having an ultrasonic imaging transducer coupled to a drive cable disposed within a lumen of a flexible tubular catheter body. An improvement including a reconfiguration of the ferrites in the hub assembly, such that the need for the gap between the ferrites is removed. A strain relief member is provide to increase the strength of the electrical transmission lines to enable them to withstand the tensile forces caused by either flushing and/or pull-back operations. A device which allows the electrical transmission lines to extend their length when placed in tension may also be employed to provide strain relief to the electrical transmission lines. Another improvement includes a counter-wound coil structure, which may either expand or contract as the drive cable is being rotated to strengthen the drive cable. The distal tip of the catheter body may be redesigned to provide a lumen which allows for the release of flushing fluids through a distal port in the guidewire lumen.

Abstract: A method of mounting a transducer to a driveshaft which eliminates the need for a transducer housing, the improved method directly attaches the transducer to a rigid distal tip of a drive-shaft which is part of a rotatable imaging core of a catheter assembly. The method contemplates heat treating the distal tip of the drive-shaft to make it rigid, machining the distal tip to be dimensioned to hold the transducer, and attaching the transducer to the distal tip by clamping, crimping, or an adhesive.

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: A combination catheter includes an ultrasound transducer and RF ablation electrode. The ultrasound transducer transmits ultrasound signals into and receives echo signals from a vessel. The echo signals are processed and used to produce an image of the tissue surrounding the catheter. A driveshaft rotates the ultrasound transducer to obtain a 360° view of the vessel wall. At the distal end of the driveshaft is an electrode. An RF generator is electrically coupled to the driveshaft to deliver RF energy to the electrode at the distal end of the driveshaft to ablate occluding material in the vessel. The electrode may have a variety of tip shapes including concave, roughened, or expandable configurations, depending on the size of the vessel and composition of the occluding material to be ablated. Alternatively, the RF ablation energy may be delivered to a guidewire that is used to route the ultrasound catheter through a patient's vasculature.