Therapeutic ultrasound system

Abstract

An ultrasound system has a catheter including an elongate flexible catheter body having at least one lumen extending longitudinally therethrough. An ultrasound transmission wire extends longitudinally through the lumen of the catheter body, and has a proximal region, a distal region, and an intermediate region between the proximal region and the distal region. A sonic connector is connected to the proximal region of the ultrasound transmission wire, and a distal head is positioned at the distal end of the catheter body and coupled to the distal region of the ultrasound transmission wire. The proximal region of the ultrasound transmission wire has a larger diameter than the intermediate region, the intermediate region is continuously tapered with a progressively decreasing diameter from its proximal end to its distal end, and the distal region has a greater diameter than the distal end of the intermediate region.

1 . An ultrasound catheter comprising:
 an elongate flexible catheter body having a proximal end, a distal end and at least one longitudinal lumen;   an ultrasound transmission wire extending through the lumen, the ultrasound transmission wire having a first proximal region, a second region, a distal region, and an intermediate region between the second region and the distal region;   a sonic connector connected to and surrounding the first proximal region; and   a distal head positioned at the distal end and coupled to the distal region;   
       wherein the first proximal region has a larger diameter than the second region, the second region has a larger diameter than the intermediate region, the intermediate region continuously tapers with a progressively decreasing diameter from its proximal end to its distal end, and the distal region has a greater diameter than the distal end of the intermediate region. 
     
     
         2 . The catheter of  claim 1  wherein the intermediate region has a plurality of progressively tapered sections, each tapered section having a distal end and a proximal end, with each tapered section having a diameter that progressively decreases from its proximal end to its distal end. 
     
     
         3 . The catheter of  claim 2  wherein the distal-most end of the ultrasound transmission wire extends beyond the distal-most end of the catheter body. 
     
     
         4 . The catheter of  claim 3  wherein the ultrasound transmission wire is made of a super-elastic metal alloy. 
     
     
         5 . The catheter of  claim 4  wherein the ultrasound transmission wire has a circular configuration over its entire length. 
     
     
         6 . The catheter of  claim 5  wherein the first proximal region of the ultrasound transmission wire has the greatest diameter. 
     
     
         7 . A method for disrupting an occlusion in a blood vessel comprising the steps of:
 positioning an ultrasound catheter in a blood vessel such that a distal end of the catheter is adjacent an occlusion;   introducing refrigerated irrigation fluid through the catheter; and   transmitting ultrasound energy through the ultrasound catheter to disrupt the occlusion into multiple occlusion fragments.   
     
     
         8 . The method of  claim 7  wherein positioning the ultrasound catheter comprises using a guiding catheter. 
     
     
         9 . The method of  claim 8  wherein positioning the ultrasound catheter comprises using a guidewire. 
     
     
         10 . The method of  claim 7  wherein positioning the ultrasound catheter comprises using a guidewire. 
     
     
         11 . The method of  claim 10  further including removing the occlusion fragments through the ultrasound catheter. 
     
     
         12 . The method of  claim 11  further including:
 providing an irrigation inlet aperture at a proximal end of the catheter; 
 and 
 introducing irrigation fluid through the aperture. 
 
     
     
         13 . The method of  claim 12  further including providing an irrigation outlet aperture at a distal end of the catheter. 
     
     
         14 . The method of  claim 13  wherein the irrigation outlet aperture includes a side hole on the distal end of the catheter. 
     
     
         15 . The method of  claim 13  wherein the irrigation outlet aperture includes a side-hole aperture at the distal end of the catheter and an outlet through the tip of the ultrasound catheter. 
     
     
         16 . The method of  claim 15  wherein the refrigerated irrigation fluid temperature is below 72 degrees Fahrenheit. 
     
     
         17 . The method of  claim 16  wherein the refrigerated irrigation fluid temperature is between 40 and 72 degrees Fahrenheit. 
     
     
         18 . The method of  claim 17  wherein the refrigerated irrigation fluid is delivered during the delivery of ultrasound energy. 
     
     
         19 . The method of  claim 18  wherein the refrigerated irrigation fluid is delivered during an interventional procedure. 
     
     
         20 . The method of  claim 19  wherein the irrigation fluid contains a pharmacological agent.