Abstract:
Ablation device including a probe structure 10 having a proximal end 12 and a distal end 14. Probe structure 10 includes a tubular first catheter 16, a tubular second catheter 18 surrounding the first catheter and a tubular guide catheter extending within the first catheter 16. The first catheter 16 carries a cylindrical ultrasonic transducer 20 adjacent its distal end. The transducer 20 is connected to a source of electrical excitation. The ultrasonic waves emitted by the transducer 20 are directed at the heart wall tissue. Once the tissue reaches the target temperature, the electrical excitation is turned on and off to maintain the tissue at the target temperature. Alternatively, the transducer 20 is subjected to continuous excitation at one power level and upon the tissue reaching the target temperature, the power level of the continuous excitation is switched to a second lower power level.
Abstract:
A cardiac ablation device, including a steerable catheter (10) and an expandable ablation element (18) incorporating one or more balloons (20, 22) at the distal end of the catheter, has a continuous passageway (28, 30) extending through it from the proximal end of the catheter to the distal side of the expandable ablation element. A probe (72) carrying electrodes is introduced through this passageway and deploys, under the influence of its own resilience, to a structure incorporating a loop (82) which is automatically aligned with the axis of the expandable ablation device, so that minimal manipulation is required to place the sensor probe.
Abstract:
A balloon catheter is provided with rigid engagement elements (260, 270) which move into engagement when the balloon (216) is inflated, so that the engaged elements stiffen the balloon in the inflated condition. When the balloon is deflated, the engagement elements are at least partially disengaged so that the balloon can flex. A stem (274) on one engagement element (270) may project into the adjacent engagement element (260) in the disengaged condition, so that the stem allows the engagement elements to pivot but constrains them to prevent kinking. A stretchable tube (238) may be provided to allow communication through the balloon, and a spring (262, 42) may be provided to elongate the balloon upon deflation.
Abstract:
Ablation device including a probe structure 10 having a proximal end 12 and a distal end 14. Probe structure 10 includes a tubular first catheter 16, a tubular second catheter 18 surrounding the first catheter and a tubular guide catheter extending within the first catheter 16. The first catheter 16 carries a cylindrical ultrasonic transducer 20 adjacent its distal end. The transducer 20 is connected to a source of electrical excitation. The ultrasonic waves emitted by the transducer 20 are directed at the heart wall tissue. Once the tissue reaches the target temperature, the electrical excitation is turned on and off to maintain the tissue at the target temperature. Alternatively, the transducer 20 is subjected to continuous excitation at one power level and upon the tissue reaching the target temperature, the power level of the continuous excitation is switched to a second lower power level.
Abstract:
Ablation apparatus such as a catheter (10) carrying an ultrasonic ablation device (20) including an ablation transducer (42) and a balloon reflector structure (22, 24) for directing ultrasonic energy from the ablation transducer into a ring-like ablation region (A) is provided with an imaging ultrasonic transducer (86) mounted on an imaging probe (80) which may be inserted into or through a passageway (18, 65) extending through the catheter and into or through the ablation device to image the ablation region or neighboring regions. Alternatively, the imaging transducer (102, 202) may be mounted within the balloon reflector structure or distal to this structure.
Abstract:
A storage unit holds representations of sensor signals which would be received by a set (30) of ultrasonic transducers (32) from an ultrasonic impulse emitter positioned at each of plural points (P) in the frame of reference of the transducer set. An impulse may be applied at a particular point by using the representation associated with that point to generate an actuation signal corresponding to a time-reversed version of the sensor signal. Impulses may be applied in a pattern (150) by using those representations associated with points in the pattern to generate actuation signals and applying those signals to the transducer set. By placing the transducer set in a known spatial relationship to the a body structure such as heart, an ablation pattern may be formed in a desired relationship to the body structure, such as around the ostium of a pulmonary vein.
Abstract:
A steerable catheter (10) has a steering portion (14) incorporating a spear cut junction of catheter material, thereby providing for a gradual change in flexibility in the steering portion. A guide tube (42) and spring (44) may be located inside a pull wire lumen (38) of catheter (10), with spring (44) distal to guide tube (42) so that spring (44) is disposed at least partially within steering section. A steering mechanism moves a pull wire (40) linearly in order to steer catheter (10).
Abstract:
Apparatus for treating cardiac arrhythmias includes an ultrasonic ablation device incorporating an ultrasonic emitter (22, 400), means (10, 14, 402, 404) for positioning the ablation device outside of the heart but adjacent the epicardial surface of the heart, and means (26, 28, 30) for focusing the ultrasonic energy emitted by the emitter into an ablation region, so that the ablation region is disposed within the wall of the heart.
Abstract:
A storage unit holds representations of sensor signals which would be received by a set (30) of ultrasonic transducers (32) from an ultrasonic impulse emitter positioned at each of plural points (P) in the frame of reference of the transducer set. An impulse may be applied at a particular point by using the representation associated with that point to generate an actuation signal corresponding to a time-reversed version of the sensor signal. Impulses may be applied in a pattern (150) by using those representations associated with points in the pattern to generate actuation signals and applying those signals to the transducer set. By placing the transducer set in a known spatial relationship to the a body structure such as heart, an ablation pattern may be formed in a desired relationship to the body structure, such as around the ostium of a pulmonary vein.
Abstract:
A steerable catheter (10) has a steering portion (14) incorporating a spear cut junction of catheter material, thereby providing for a gradual change in flexibility in the steering portion. A guide tube (42) and spring (44) may be located inside a pull wire lumen (38) of catheter (10), with spring (44) distal to guide tube (42) so that spring (44) is disposed at least partially within steering section. A steering mechanism moves a pull wire (40) linearly in order to steer catheter (10).