Ultrasound tissue treatment apparatus and method

An apparatus comprising:

• a catheter having a distal end and a proximal end, the catheter comprising:
• a rotatable element at the distal end of the catheter configured to apply a treatment to a subject when disposed at a plurality of different rotational positions;
• a handle at the proximal end of the catheter;
• and
• a drive cable extending distally from within the handle to the rotatable element at the distal end of the catheter, the drive cable being configured to transmit rotational motion from within the handle to the rotatable element;
• and
• a motor configured, during the treatment, to drive the rotatable element to undergo rotational movements between the plurality of different rotational positions, and to reduce static friction acting upon the rotatable element between the rotational movements, by driving the rotatable element to continuously move axially between the rotational movements of the rotatable element.

An apparatus for use with a fluid, the apparatus comprising:

• a catheter having a distal end and a proximal end, the catheter comprising:
• a rotatable element at the distal end of the catheter configured to apply a treatment to a subject when disposed at a plurality of different rotational positions;
• a handle at the proximal end of the catheter;
• and
• a drive cable extending distally from within the handle to the rotatable element at the distal end of the catheter, the drive cable being configured to transmit rotational motion from within the handle to the rotatable element, the drive-cable defining a drive-cable fluid inflow lumen and a drive-cable fluid outflow lumen;
• and
• a fluid manifold, comprising:
• a fluid entry port;
• a fluid exit port;
• a rotationally static portion that contains a rotationally-static fluid inflow lumen, which is in fluid communication with the fluid entry port, and a rotationally-static fluid outflow lumen, which is in fluid communication with the fluid exit port;
• and
• a rotational portion that is configured to rotate with the drive cable, the rotational portion defining:
• a rotational fluid inflow lumen that is in fluid communication with both the rotationally-static fluid inflow lumen and the drive-cable fluid inflow lumen, thereby placing the rotationally-static fluid inflow lumen and the drive-cable fluid inflow lumen in fluid communication with each other;
• and
• a rotational fluid outflow lumen that is in fluid communication with the rotationally-static fluid outflow lumen and the drive-cable fluid outflow lumen, thereby placing the rotationally-static fluid outflow lumen and the drive-cable fluid outflow lumen in fluid communication with each other.