Abstract: An imaging catheter assembly is provided. In one embodiment, the imaging catheter assembly includes a flexible elongate member including a distal portion and a proximal portion; and an imaging component coupled to the distal portion of the flexible elongate member, wherein the imaging component includes: an integrated circuit (IC) layer that includes a semiconductor material; an array of ultrasound transducer elements coupled to a first side of the IC layer; and a backing layer coupled to a second side of the IC layer opposite the first side, wherein the backing layer includes a backing material, and wherein a coefficient of thermal expansion (CTE) difference between the semiconductor material and the backing material is less than 23 parts per million per degree Centigrade (ppm/C).

Abstract: An imaging catheter assembly is provided. In one embodiment, the imaging catheter assembly includes a flexible elongate member including a distal portion and a proximal portion; and an imaging component coupled to the distal portion of the flexible elongate member, wherein the imaging component includes: an integrated circuit (IC) layer that includes a semiconductor material; an array of ultrasound transducer elements coupled to a first side of the IC layer; and a backing layer coupled to a second side of the IC layer opposite the first side, wherein the backing layer includes a backing material, and wherein a coefficient of thermal expansion (CTE) difference between the semiconductor material and the backing material is less than 23 parts per million per degree Centigrade (ppm/C).

Abstract: The invention relates to a capacitive micro-machined ultrasound transducer (CMUT) cell (6) comprising a cell floor (31) having a first electrode (7); a cell membrane (5) having a second electrode (7?) which opposes the first electrode and vibrates during transmission or reception of acoustic energy; a transmitter/receiver coupled to the first and second electrodes which causes the cell membrane to vibrate at an acoustic frequency and/or receives signals at an acoustic frequency; and an acoustic lens (13), overlaying the cell membrane, and having an inner surface opposing the cell membrane and an outer, patient-facing surface. According to the present invention the acoustic lens comprises at least one layer of a material selected from the group of: polybudatiene, polyether block amide (PEBAX), polydimethylsiloxane (PDMS) and buthylrubber.

Abstract: An array of CMUT cells has a DC bias voltage coupled to the top electrodes of the cells to bias the electrode to a desired collapsed or partially collapsed state. In the event of a short-circuit failure of a CMUT cell a protection circuit for the cell senses an over-current condition and responds by opening the DC current path through the failed cell. The protection circuit further disables the transmit and receive circuitry of the cell. In another implementation a sense circuit senses an over-current condition of the DC bias supply and responds by disabling all of the CMUT cells of the array, then sequentially re-enabling them, except that an attempt to re-enable a failed cell results in that cell remaining in a disabled state.

Abstract: An array of CMUT cells (10) has a DC bias voltage (VB) coupled to the top electrodes of the cells to bias the electrode to a desired collapsed or partially collapsed state. Fuses (200) are coupled in series with the bottom electrodes (22) of the cells which will open and isolate an individual cell from the other still-functional cells of the array in the event of a failure of the individual cell. In a preferred embodiment the cells are coupled to control integrated circuitry such as microbeamformer circuitry and the fuses are formed of semiconductor materials with the integrated circuitry, thereby leaving the MUT surface area available for high density MUT fabrication. Damage to the integrated circuitry due to short-circuiting of the DC bias current through a failed cell is prevented.

Abstract: Systems, methods, and apparatuses for coupling a flexible transducer to an object are described. A transducer positioning device may include an inflatable bladder and a strap. The inflatable bladder may apply a force to a transducer array to maintain its position against the object when inflated. The strap may hold the bladder against the transducer array. Once in place, the bladder may be inflated with a fluid.

Abstract: An ultrasound transducer assembly (10) is disclosed comprising a plurality of transducer elements (32) for transmitting and receiving ultrasound waves (24) each having a substrate (40) and a flexible membrane (46) disposed in a distance from a substrate. An AC voltage control unit (56) is provided for controlling an AC voltage provided to each of the transducer elements, and a DC voltage control unit (60) for controlling a DC bias voltage provided to the transducer elements in order to bring the flexible membranes in a collapse mode into contact with the substrate. The DC voltage control unit is adapted to disconnect the DC bias voltage from the transducer elements temporarily during the operation of the ultrasound transducer assembly to limit the collapse mode.

Abstract: An imaging catheter assembly is provided. In one embodiment, the imaging catheter assembly includes a flexible elongate member including a distal portion and a proximal portion; and an imaging component coupled to the distal portion of the flexible elongate member, wherein the imaging component includes: an integrated circuit (IC) layer that includes a semiconductor material; an array of ultrasound transducer elements coupled to a first side of the IC layer; and a backing layer coupled to a second side of the IC layer opposite the first side, wherein the backing layer includes a backing material, and wherein a coefficient of thermal expansion (CTE) difference between the semiconductor material and the backing material is less than 23 parts per million per degree Centigrade (ppm/C).

Abstract: A matrix array probe including a transducer array and integrated circuitry coupled to the transducer elements dissipates heat generated by the array and integrated circuitry through the cover of the transducer probe. A pump in the probe connector pumps fluid through a closed loop system including inbound an outbound fluid conduits in the cable. The fluid conduits in the cable are separated by the cable electrical conductors for the probe. The heat transfer in the probe is done by a heat exchanger in the transducer backing block. Additional cooling may be provided by metal to metal contact with a chiller in the ultrasound system.

Abstract: An array of CMUT cells (10) has a DC bias voltage (VB) coupled to the top electrodes of the cells to bias the electrode to a desired collapsed or partially collapsed state. Fuses (200) are coupled in series with the bottom electrodes (22) of the cells which will open and isolate an individual cell from the other still-functional cells of the array in the event of a failure of the individual cell. In a preferred embodiment the cells are coupled to control integrated circuitry such as microbeamformer circuitry and the fuses are formed of semiconductor materials with the integrated circuitry, thereby leaving the MUT surface area available for high density MUT fabrication. Damage to the integrated circuitry due to short-circuiting of the DC bias current through a failed cell is prevented.

Abstract: An array of CMUT cells has a DC bias voltage coupled to the top electrodes of the cells to bias the electrode to a desired collapsed or partially collapsed state. In the event of a short-circuit failure of a CMUT cell a protection circuit for the cell senses an over-current condition and responds by opening the DC current path through the failed cell. The protection circuit further disables the transmit and receive circuitry of the cell. In another implementation a sense circuit senses an over-current condition of the DC bias supply and responds by disabling all of the CMUT cells of the array, then sequentially re-enabling them, except that an attempt to re-enable a failed cell results in that cell remaining in a disabled state.

Abstract: Systems, methods, and apparatuses for coupling a flexible transducer to an object are described. A transducer positioning device may include an inflatable bladder and a strap. The inflatable bladder may apply a force to a transducer array to maintain its position against the object when inflated. The strap may hold the bladder against the transducer array. Once in place, the bladder may be inflated with a fluid.

Abstract: A matrix array probe including a transducer array and integrated circuitry coupled to the transducer elements dissipates heat generated by the array and integrated circuitry through the cover of the transducer probe. A pump in the probe connector pumps fluid through a closed loop system including inbound an outbound fluid conduits in the cable. The fluid conduits in the cable are separated by the cable electrical conductors for the probe. The heat transfer in the probe is done by a heat exchanger in the transducer backing block. Additional cooling may be provided by metal to metal contact with a chiller in the ultrasound system.

Abstract: A backing block for an ultrasonic transducer array stack of an ultrasound probe is formed as a composite structure of graphite foam impregnated with an epoxy resin. The epoxy resin penetrates the porous foam structure at least part-way into the depth of the graphite foam block and, when cured, provides the backing block with good structural stability. The composite graphite foam backing block is bonded to the integrated circuit of a transducer to provide high thermal conductivity away from the transducer and good acoustic attenuation or scattering of rearward acoustic reverberations.

Abstract: A matrix array probe including a transducer array and integrated circuitry coupled to the transducer elements dissipates heat generated by the array and integrated circuitry through the cover of the transducer probe. A pump in the probe connector pumps fluid through a closed loop system including inbound an outbound fluid conduits in the cable. The fluid conduits in the cable are separated by the cable electrical conductors for the probe. The heat transfer in the probe is done by a heat exchanger in the transducer backing block. Additional cooling may be provided by metal to metal contact with a chiller in the ultrasound system.

Abstract: A matrix array ultrasound probe passively dissipates heat developed by the matrix array transducer and beamformer ASIC away from the distal end of the probe. The heat developed in the transducer stack is coupled to a metallic frame inside the handle of probe. A metallic heatspreader is thermally coupled to the probe frame to convey heat away from the frame. The heatspreader surrounds the inside of the probe handle and has an outer surface which is thermally coupled to the inner surface of the probe housing. Heat is thereby coupled evenly from the heatspreader into the housing without the development of hotspots in the housing which could be uncomfortable to the hand of the sonographer.

Abstract: An ultrasound transducer assembly (10) is disclosed comprising a plurality of transducer elements (32) for transmitting and receiving ultrasound waves (24) each having a substrate (40) and a flexible membrane (46) disposed in a distance from a substrate. An AC voltage control unit (56) is provided for controlling an AC voltage provided to each of the transducer elements, and a DC voltage control unit (60) for controlling a DC bias voltage provided to the transducer elements in order to bring the flexible membranes in a collapse mode into contact with the substrate. The DC voltage control unit is adapted to disconnect the DC bias voltage from the transducer elements temporarily during the operation of the ultrasound transducer assembly to limit the collapse mode.

Abstract: The invention relates to a capacitive micro-machined ultrasound transducer (CMUT) cell (6) comprising a cell floor (31) having a first electrode (7); a cell membrane (5) having a second electrode (7?) which opposes the first electrode and vibrates during transmission or reception of acoustic energy; a transmitter/receiver coupled to the first and second electrodes which causes the cell membrane to vibrate at an acoustic frequency and/or receives signals at an acoustic frequency; and an acoustic lens (13), overlaying the cell membrane, and having an inner surface opposing the cell membrane and an outer, patient-facing surface. According to the present invention the acoustic lens comprises at least one layer of a material selected from the group of: polybudatiene, polyether block amide (PEBAX), polydimethylsiloxane (PDMS) and buthylrubber.

Abstract: A backing block for an ultrasonic transducer array stack of an ultrasound probe is formed as a composite structure of material of high thermal conductivity in which is embedded a structure of acoustic dampening material. In a constructed embodiment the composite structure is formed from a block of thermally conductive graphite in which a plurality of cylindrical holes are formed which are filled with acoustic dampening material. The holes are angled in relation to the Z-axis direction from the rear of the transducer stack so that reverberation energy traveling in that direction will encounter acoustic dampening material. The graphite around the holes is effective to conduct heat to the rear of the probe and away from the transducer stack and its ASIC.

Abstract: A matrix array probe including a transducer array and integrated circuitry coupled to the transducer elements dissipates heat generated by the array and integrated circuitry through the cover of the transducer probe. A pump in the probe connector pumps fluid through a closed loop system including inbound an outbound fluid conduits in the cable. The fluid conduits in the cable are separated by the cable electrical conductors for the probe. The heat transfer in the probe is done by a heat exchanger in the transducer backing block. Additional cooling may be provided by metal to metal contact with a chiller in the ultrasound system.