# US 5,931,805 A · Catheters comprising bending transducers and methods for their use > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,931,805 A - Document ID: US5931805A - Status: Granted - Kind: A - Application number: 08/867,007 - Filed: 1997-06-02 - Granted: 1999-08-03 - Earliest claimed: 1997-06-02 - Assignees: Pharmasonics, Inc. - Inventors: Axel F. Brisken - Web page: https://patentgrep.com/patent/US5931805A ## CPC - A61B 17/22012: {in direct contact with, or very close to, the obstruction or concrement (for removing obstructions in blood vessels by laser A61B18/245)} - A61B 2017/22038: {with a guide wire} - A61B 2017/22051: {with an inflatable part, e.g. balloon, for positioning, blocking, or immobilisation (A61B2017/22048, A61B2017/3486 take precedence)} - A61B 2017/22072: {with an instrument channel, e.g. for replacing one instrument by the other} - A61B 2017/22082: {after introduction of a substance} - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract A catheter comprises a catheter body having a bending plate transducer disposed at or near its distal end. The bending plate transducer is typically a unimorph, bimorph, or other conventional vibratory transducer capable of imparting pressure waves in a direction generally normal to the plane of the transducer. The bending plate transducers may be disposed at a distal end of the catheter body, for example, as a cantilever beam, or may alternately be disposed within the catheter body. The catheters may further comprise lumens for drug delivery, balloons for encircling the transducer structures, or the like. The catheters are useful in a variety of lumenal therapeutic procedures, including drug delivery, stenotic disruption within blood vessel, and the like. ## Claims ### Claim 1 A catheter comprising: a catheter body having a proximal end and a distal end; and a bending plate transducer attached to the catheter body near the distal end thereof, the transducer arranged to vibrationally flex about an axis within a plane of the transducer. ### Claim 2 (depends on 1) A catheter as in claim 1, wherein at least a portion of the transducer projects distally from the distal end of the catheter body. ### Claim 3 (depends on 1) A catheter as in claim 1, wherein the transducer is disposed within the catheter body. ### Claim 4 (depends on 1) A catheter as in claim 1, wherein the transducer comprises at least one active layer which oscillates axially when energized and at least one opposed layer which constrains or oscillates non-synchronously relative to the active layer, wherein the relative axial displacement of the active and opposed layers causes transverse flexing of the transducer. ### Claim 5 (depends on 4) A catheter as in claim 4, wherein the active layer comprises a piezoelectric material. ### Claim 6 (depends on 5) A catheter as in claim 5, wherein the opposed layer comprises an inactive material laminated to a face of the active layer to constrain axial displacement and cause transverse bending. ### Claim 7 (depends on 6) A catheter as in claim 6, wherein the inactive material is a metal sheet laminated to the face of the active layer. ### Claim 8 (depends on 7) A catheter as in claim 7, wherein the piezoelectric layer has a thickness in the range from 0.1 mm to 1 mm and the metal sheet has a thickness in the range from 0.05 mm to 0.5 mm. ### Claim 9 (depends on 8) A catheter as in claim 8, wherein the transducer further comprises a second active layer composed of a piezoelectric material laminated to an opposite face of the inactive metal layer, said second active piezoelectric layer having a thickness in the range from 0.1 mm to 1 mm. ### Claim 10 (depends on 4) A catheter as in claim 4, wherein the opposed layer comprises an active piezoelectric material. ### Claim 11 (depends on 10) A catheter as in claim 10, wherein the piezoelectric material of the active layer has a polarity opposite to that of the piezoelectric material of the opposed layer, wherein the active layer and opposed layer are energized in phase. ### Claim 12 (depends on 10) A catheter as in claim 10, wherein the piezoelectric material of the active layer has a polarity which is the same as that of the piezoelectric material of the opposed layer, wherein the active layer and opposed layer are energized out-of-phase. ### Claim 13 (depends on 1) A catheter as in claim 1, wherein the transducer comprises a layer of ion impregnated piezoelectric ceramic material. ### Claim 14 (depends on 1) A catheter as in claim 1, further comprising a balloon disposed near the distal end of the catheter body over at least a portion of the bending plate transducer. ### Claim 15 (depends on 1) A catheter as in claim 1, further comprising at least a second bending plate transducer disposed near the distal end of the catheter body. ### Claim 16 (depends on 1) A catheter as in claim 1, further comprising means for delivering a fluid agent from the proximal end of the catheter body to a region near the bending plate transducer at the distal end thereof. ### Claim 17 (depends on 1) A catheter as in claim 1, wherein the bending plate transducer is an annular disk disposed transversely to the axis of the catheter body. ### Claim 18 A method for intralumenal delivery of vibrational energy to a body lumen, said method comprising: providing a catheter having a bending plate transducer near a distal end thereof; positioning the catheter with a body lumen so that the transducer lies adjacent a target site within the body lumen; and energizing the transducer to vibrationally flex the transducer about an axis within the plane of the transducer. ### Claim 19 (depends on 18) A method as in claim 18, wherein the transducer vibrates at a frequency in the range from 1 kHz to 40 kHz. ### Claim 20 (depends on 19) A method as in claim 19, wherein the transducer vibrates with an amplitude of at least 5 .mu.m at its distal tip when energized at the target site. ### Claim 21 (depends on 18) A method as in claim 18, wherein the body lumen is a blood vessel and the target site is a stenosed region. ### Claim 22 (depends on 21) A method as in claim 21, wherein the stenosed region has previously been treated by angioplasty. ### Claim 23 (depends on 18) A method as in claim 18, further comprising releasing a therapeutic agent at the target site. ### Claim 24 (depends on 23) A method as in claim 23, wherein the therapeutic agent is released prior to energizing the transducer. ### Claim 25 (depends on 23) A method as in claim 23, wherein the therapeutic agent is released while energizing the transducer. ### Claim 26 (depends on 18) A method as in claim 18, further comprising inflating a balloon around the transducer within the body lumen while the transducer is being energized.