# US 2014/0155747 A1 · Ultrasonic transducer > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2014/0155747 A1 - Document ID: US20140155747A1 - Status: Published application - Kind: A1 - Application number: 13/692,338 - Filed: 2012-12-03 - Published: 2014-06-05 - Earliest claimed: 2012-12-03 - Assignees: LipoSonix, Inc. - Applicants: Liposonix, Inc. - Inventors: Frederick Jay Bennett; John P. Collins; Blake W. Little - Web page: https://patentgrep.com/patent/US20140155747A1 ## CPC - A61B 8/4494: {characterised by the arrangement of the transducer elements} - A61B 8/14: Echotomography - A61B 8/4444: {related to the probe} - A61B 8/54: {Control of the diagnostic device} - A61N 7/02: Localised ultrasound hyperthermia - B06B 1/0625: {Annular array} - H04R 31/00: Apparatus or processes specially adapted for the manufacture of transducers or diaphragms therefor {(manufacture of microstructural arrangements of deformable or non-deformable structures in general B81C1/00182)} - A61B 8/4405: {Device being mounted on a trolley} - A61N 2007/0052: {using the same transducer for therapy and imaging} - A61N 2007/0082: {Scanning transducers} - Y10T 29/49005: Acoustic transducer - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) - B06B: METHODS OR APPARATUS FOR GENERATING OR TRANSMITTING MECHANICAL VIBRATIONS OF INFRASONIC, SONIC, OR ULTRASONIC FREQUENCY, {e.g.} FOR PERFORMING MECHANICAL WORK IN GENERAL (for particular applications, see the relevant subclasses, e.g. B07B1/40, B23Q17/12, B24B31/06; measurement of mechanical vibrations G01H; in direction finding, locating, distance or velocity measuring G01S; {generating seismic energy G01V1/02}; control of mechanical vibrations in general G05D; sound-producing devices, e.g. bells, sirens, whistles G10K, {e.g. methods or devices for transmitting, conducting, or directing sound in general G10K11/00}; generation of electrical oscillations H03B; electromechanical resonators in general H03H; electromechanical transducers {for communication techniques, e.g. microphones, speakers} H04R) - H04R: LOUDSPEAKERS, MICROPHONES, GRAMOPHONE PICK-UPS OR LIKE ACOUSTIC ELECTROMECHANICAL TRANSDUCERS; ELECTRIC HEARING AIDS; PUBLIC ADDRESS SYSTEMS (producing sounds with frequency not determined by supply frequency G10K) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## Abstract An ultrasound transducer and methods of fabricating and using the ultrasound transducer. The ultrasound transducer includes a composite layer having a first surface and comprising a plurality of piezoelectric elements separated by isolating material filled kerfs. The composite layer is configured so that the first surface includes an exposed face of each element of the plurality of piezoelectric elements. The transducer further includes a plurality of electrodes defined on the first surface, the electrodes having boundaries configured so that none of the exposed faces are in contact with more than one of the plurality of electrodes. The electrodes may be defined in a conductive layer deposited on the first surface of the composite body by forming a channel in the conductive layer that is aligned vertically with the dielectric kerfs. The transducer may be used to scan a treatment region with both HIFU and imaging ultrasound signals. ## Claims ### Claim 1 An apparatus comprising: a composite layer having a first surface and a second surface generally parallel to the first surface, the composite layer including an isolating material and a plurality of piezoelectric elements, each piezoelectric element being suspended in the isolating material and having a first face exposed on the first surface of the composite layer; and a plurality of electrodes on the first surface of the composite layer, each electrode being directly coupled to the first face of at least one of the piezoelectric elements, and each electrode shaped such that the first face of each piezoelectric element is directly coupled to no more than one electrode. ### Claim 2 (depends on 1) The apparatus of claim 1 wherein the electrodes are annular and are concentrically arranged with a constant pitch. ### Claim 3 (depends on 1) The apparatus of claim 1 wherein the composite layer further includes kerfs filled with the isolating material, and each piezoelectric element is isolated from adjacent piezoelectric elements by the kerfs. ### Claim 4 (depends on 3) The apparatus of claim 3 further comprising: one or more channels between the electrodes, the one or more channels being vertically aligned with the kerfs and electrically isolating each electrode from adjacent electrodes. ### Claim 5 (depends on 1) The apparatus of claim 1 wherein each piezoelectric element of the plurality of piezoelectric elements includes: a piezoelectric section including the first face and a second face opposite the first face; and a de-matching section coupled to the second face of the piezoelectric section, the de-matching section having an acoustical impedance that causes acoustic energy incident on the de-matching section from the piezoelectric section to be reflected back toward the piezoelectric section. ### Claim 6 (depends on 5) The apparatus of claim 5 further comprising: a heat sink thermally coupled to the de-matching section of each piezoelectric section. ### Claim 7 (depends on 5) The apparatus of claim 5 further comprising: an ultrasound transceiver electrically coupled with the de-matching section of each piezoelectric section. ### Claim 8 (depends on 5) The apparatus of claim 5 wherein each piezoelectric section has a thickness that is less than one half of a wavelength of a center frequency of an operational frequency range. ### Claim 9 (depends on 8) The apparatus of claim 8 wherein the thickness of each piezoelectric section is about a quarter of the wavelength of the center frequency. ### Claim 10 (depends on 1) The apparatus of claim 1 wherein the first surface of the composite layer is planar. ### Claim 11 (depends on 1) The apparatus of claim 1 further comprising: a treatment head including an actuator coupled to the composite layer and a chamber that encloses the composite layer; a transceiver operatively coupled to the electrodes on the first surface of the composite layer; and a controller operatively coupled to the actuator and the transceiver, the controller configured to selectively activate the transceiver to: transmit first electrical signals to the electrodes that generate a High Intensity Focused Ultrasound (HIFU) focal zone; transmit second electrical signals to the electrodes that generate an ultrasound imaging beam; and to receive third electrical signals from the electrodes corresponding to echoes of the ultrasound imaging beam, the controller being further configured to generate an ultrasound image from the third electrical signals received by the transceiver. ### Claim 12 (depends on 11) The apparatus of claim 11, wherein the controller is further configured to operate the actuator so that the HIFU focal zone is scanned along a first plurality of scan lines in a treatment region, and the ultrasound imaging beam is scanned along a second plurality of scan lines in the treatment region. ### Claim 13 (depends on 12) The apparatus of claim 12 wherein the controller is configured to operate the actuator so that the first plurality of scan lines are interleaved with the second plurality of scan lines. ### Claim 14 A method of fabricating an ultrasound transducer, the method comprising: providing a substrate that includes a piezoelectric layer; forming a plurality of kerfs in the substrate to define a plurality of piezoelectric elements that are separated by the kerfs; filling the kerfs with an isolating material to form a composite layer having a first surface, the composite layer including the plurality of piezoelectric elements, each of the piezoelectric elements being separated from adjacent piezoelectric elements by the isolating material; and forming a plurality of electrodes on the first surface of the composite layer, the electrodes being defined so that each piezoelectric element is directly coupled to no more than one electrode. ### Claim 15 (depends on 14) The method of claim 14 wherein forming the plurality of electrodes includes: depositing a conductive layer on the first surface of the composite layer; and forming a plurality of channels in the conductive layer, the channels defining the electrodes and being vertically aligned with the kerfs. ### Claim 16 (depends on 14) The method of claim 14 wherein forming the plurality of kerfs in the substrate includes: bonding a support layer to a second surface of the substrate; curing the isolating material so that the isolating material changes from a fluid state into a solid state; in response to the isolating material being cured, removing the support layer from the second surface; and lapping the second surface of the composite layer to obtain a desired thickness of the composite layer. ### Claim 17 (depends on 14) The method of claim 14 further comprising: lapping the first surface of the composite layer to expose a face of each piezoelectric element. ### Claim 18 (depends on 14) The method of claim 14 wherein providing the substrate includes bonding a layer of de-matching material to the piezoelectric layer. ### Claim 19 A method of treating a patient with ultrasound, the method comprising: generating a High Intensity Focused Ultrasound (HIFU) focal zone with a transducer; scanning the HIFU focal zone across a treatment region to provide a therapeutic dose of ultrasound energy to a portion of the treatment region; generating an ultrasound imaging beam with the transducer; scanning the ultrasound imaging beam across the treatment region; receiving echoes of the ultrasound imaging beam with the transducer; and generating an image of the portion of the treatment region from the received echoes. ### Claim 20 (depends on 19) The method of claim 19 wherein: scanning the HIFU focal zone across the treatment region includes scanning the HIFU focal zone along a first plurality of scan lines in the treatment region, and scanning the ultrasound imaging beam across the treatment region includes scanning the ultrasound imaging beam along a second plurality of scan lines in the treatment region. ### Claim 21 (depends on 20) The method of claim 20 wherein scanning the ultrasound imaging beam along the second plurality of scan lines in the treatment region includes interleaving the second plurality of scan lines with the first plurality of scan lines. ### Claim 22 (depends on 19) The method of claim 19 wherein generating the HIFU focal zone comprises: generating at least one ultrasound burst having a first duration. ### Claim 23 (depends on 22) The method of claim 22 wherein generating the ultrasound imaging beam comprises: generating a plurality of ultrasound bursts each having a second duration less than the first duration. ### Claim 24 (depends on 19) The method of claim 19 further comprising: adjusting at least one of a power level of the HIFU focal zone, a scan speed of the HIFU focal zone, and a position of the HIFU focal zone within the treatment region based on the image generated from the received echoes. ### Claim 25 (depends on 19) The method of claim 19 wherein: generating the ultrasound imaging beam with the transducer includes generating a burst of ultrasound energy; and generating the image of the portion of the treatment region from the received echoes includes electrically adjusting a focal distance of the transducer based on an amount of time since the burst of ultrasound energy so that the focal distance corresponds to a depth of the treatment region from which an echo of the burst is expected.