Abstract: An ablation and cutting catheter (10), which may be used for angioplasty, includes a rotary shaft (20) adapted to be driven by a rotary motor (22). The shaft (20) is free for rotation and for some axial motion. The shaft (20) is coupled to a rotational-to-axial motion converter (FIGS. 2a, 2b, 2c; 3a, 3b, 3c) which is affixed to the shaft. The converter moves axially in response to rotation of the shaft, and also rotates. The axial motion is converted into acoustic energy for ablation, and the rotation can be used with a cutting tool for cutting. A guide-wire lumen exteds through the shaft and the cutter/acoustic applicator head, for accepting a guide-wire for guiding the catheter.

Abstract: An acoustic ablation catheter driven by a rotating shaft (18) includes a rotary-to-axial-motion converter (210), which includes a rotary driver (220, 420) in the form of a shell (222, 422) defining an inner surface (228, 428) which features a depressed groove (230, 330, 430). A follower (250, 490, 724) includes protuberance(s) (254, 494) which extend radially outward to engage the groove. This arrangement provides higher frequency response than some prior-art arrangements, and has the advantage of lesser diameter. In a particular embodiment, the shell (422) is made up of a cylinder (422) with a smooth interior, together with two end pieces (470, 480) which have axially-directed bumps or teeth (472, 482) which together define the guide path (330, 430). In a particular embodiment of the invention, the body (12) of the catheter (10) is made from a braided tube impregnated with a cured liquid, such as polymer.

Abstract: A catheter 10 according to the invention includes an elongated shaft 14 defining a distal end 12 and a proximal end 13. The proximal end of the shaft includes a coupling arrangement 15 for coupling to a rotary drive such as an external rotary motor. The catheter also includes a rotary-to-axial motion converter 28 coupled to the distal end of the shaft 14. The rotary-to-axial-motion converter 28 includes at least a first magnetic pole pair 22N, 22S mechanically coupled to the distal end of the shaft 14 for being rotated thereby along an arc. The motion converter also includes a nonrotating reciprocating follower 30, and at least a second magnetic pole pair 30N, 30S which is located so as to come within the magnetic influence of the first magnetic pole pair 22N, 22S during each the rotation of the shaft 14. During each rotation, the two magnetic poles attract or repel, for causing reciprocating axial motion of the reciprocating follower 30.

Abstract: An acoustic catheter reduces transmission losses and unwanted heating of the transmission member by driving the catheter a rotary motor. The catheter includes an elongated body and a shaft extending longitudinally therethrough. The shaft is adapted for coupling to a rotary motor. A rotary-to-axial motion converter is coupled to the shaft at distal end of the catheter, for converting rotary shaft motion into axial acoustic motion. In one embodiment, the rotary-to-axial motion converter includes a swash plate driven by the shaft. The swash plate defines a surface which, at an angularly fixed reference point, moves axially in response to the rotary motion of the swash plate. A follower bears on the swash plate, for moving axially in response to axial motion of the follower. The follower includes a projection bearing on the swash plate and a spring urging the follower toward the swash plate. In one embodiment, the swash plate has a sinusoidal surface, while another embodiment has notches cut into the surface.