Patent Description:
Ultrasound imaging systems are widely used for medical imaging and measurement. For example, ultrasound imaging systems may be used to make measurements of organs, lesions, tumors, or other structures within a patient's anatomy. During ultrasound imaging procedures, a user of the ultrasound imaging system brings a probe into contact with the body of a patient. An array of elements within the probe emit acoustic energy into the patient and receive reflected waves used to construct an image of the patent anatomy. Many transducer arrays use piezo-electric materials to generate acoustic energy. While generating acoustic energy to transmit into the patent anatomy, these piezo-electric transducers and materials in the acoustic path also generate heat causing the temperature within the probe to rise. Increasing the amplitude of transmitted acoustic waves generally increases the quality of ultrasound images acquired by the ultrasound system, but increasing this amplitude also increases heat generated. If the temperature of the probe is not controlled, this heat may cause discomfort or physical harm to a patient.

Government regulations determine what amount of temperature rise within a medical ultrasound transducer is permissible. As a result, power transmitted to a medical ultrasound transducer is often limited by temperature rise. In addition, dissipating heat from an ultrasound probe has proven challenging because it is often generated within, and/or surrounded by, materials with low thermal conductivity.

<CIT> discloses an ultrasonic probe which has a heat absorbing backing layer, a heat spreader underneath the backing layer, and a heat pipe which extends between the heat spreader and a heat radiation plate to transfer heat to an exterior of the ultrasonic probe.

<CIT> discloses an ultrasonic probe having a support structure using a thermally conductive material.

of the present disclosure are systems, devices, and methods for efficiently dissipating heat from an ultrasound transducer with a low resistance thermal path. As heat is generated by the transducer array, it may be absorbed and dissipated by a heatsink positioned behind the transducer array. The heatsink includes a set of fins extending from the heatsink towards the transducer array. These heatsink fins are embedded within an acoustic backing material with highly attenuative properties. One end of one or more heat pipes also contacts the heatsink and extends along the length of the ultrasound probe. Heat may be transferred from the heatsink to these heat pipes via a thermal interface material. At the other end of the heat pipes, the pipes are brought into contact with a heat spreader material that is adhered to the inner surface of the ultrasound probe housing. Heat may pass from the heat pipes to the heat spreader material via additional thermal interface material, such as a gap filling paste. From the heat spreader material, heat may then be dissipated to the ultrasound probe housing and to the surrounding environment.

The low resistance thermal path described advantageously allows the transducer array of the ultrasound probe to emit higher power acoustic energy without exceeding regulatory limits on transducer face temperature. This results in a lower operating temperature and increased emitting power for the probe. The increased emitting power allows the ultrasound system to generate higher quality ultrasound data, which can improve how helpful the ultrasound data is for a physician making diagnostic and/or therapeutic decisions and therefore the patient's health.

Any alterations and further modifications to the described devices, and any further application of the principles of the present disclosure are fully contemplated and included within the present disclosure as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to other embodiments of the present disclosure.

<FIG> is a diagrammatic perspective view of an ultrasound imaging system <NUM>, according to aspects of the present disclosure. The ultrasound imaging system <NUM> includes a console <NUM> and an ultrasound probe <NUM>. The ultrasound imaging system <NUM> may be used to obtain and display ultrasound images of anatomy. In some circumstances, the system <NUM> may include additional elements and/or may be implemented without one or more of the elements illustrated in <FIG>.

The ultrasound probe <NUM> is sized and shaped, structurally arranged, and/or otherwise configured to be placed on or near the anatomy of a subject to visualize anatomy inside of the subject's body. The subject may be a human patient or animal. The ultrasound probe <NUM> may be positioned outside the body of the subject. In some embodiments, the ultrasound probe <NUM> is positioned proximate to and/or in contact with the body of the subject. For example, the ultrasound probe <NUM> may be placed directly on the body of the subject and/or adjacent to the body of the subject. The view of the anatomy shown in the ultrasound image depends on the position and orientation of the ultrasound probe <NUM>. To obtain ultrasound data of the anatomy, the ultrasound probe <NUM> can be suitably positioned and oriented by a user, such as a physician, sonographer, and/or other medical personnel, so that a transducer array <NUM> emits ultrasound waves and receives ultrasound echoes from the desired portion of the anatomy. The ultrasound probe <NUM> may be portable and suitable for use in a medical setting. In some instances, the ultrasound probe <NUM> can be referenced as an ultrasound imaging device, a diagnostic imaging device, external imaging device, transthoracic echocardiography (TTE) probe, and/or combinations thereof.

The ultrasound probe <NUM> includes a housing <NUM> structurally arranged, sized and shaped, and/or otherwise configured for handheld grasping by a user. The housing <NUM> can be referenced as a handle in some instances. A proximal portion <NUM> of the housing <NUM> can be referenced as a handle in some instances. The housing <NUM> surrounds and protects the various components of the imaging device <NUM>, such as electronic circuitry <NUM> and the transducer array <NUM>. Internal structures, such as a space frame for securing the various components, may be positioned within the housing <NUM>. In some embodiments, the housing <NUM> includes two or more portions which are joined together during manufacturing. The housing <NUM> can be formed from any suitable material, including a plastic, a polymer, a composite or combinations thereof.

The housing <NUM> and/or the ultrasound probe <NUM> includes the proximal portion <NUM> terminating at a proximal end <NUM> and a distal portion <NUM> terminating at a distal end <NUM>. In some instances, the ultrasound probe <NUM> can be described as having the proximal portion <NUM> and the distal portion <NUM>. An imaging assembly of the ultrasound probe <NUM>, including the transducer array <NUM>, is disposed at the distal portion <NUM>. All or a portion of the imaging assembly of the ultrasound probe <NUM> can define the distal end <NUM>. The transducer array <NUM> can be directly or indirectly coupled to the housing <NUM>. The operator of the ultrasound probe <NUM> may contact the distal end <NUM> of the ultrasound probe <NUM> to the body of the patient such that the anatomy is compressed in a resilient manner. For example, the imaging assembly, including the transducer array <NUM>, may be placed directly on or adjacent to the body of the subject. In some instances, the distal portion <NUM> is placed directly in contact with the body of the subject such that the transducer array <NUM> is adjacent to the body of the subject.

The ultrasound probe <NUM> is configured to obtain ultrasound imaging data associated with any suitable anatomy of the patient. For example, the ultrasound probe <NUM> may be used to examine any number of anatomical locations and tissue types, including without limitation, organs including the liver, heart, kidneys, gall bladder, pancreas, lungs; ducts; intestines; nervous system structures including the brain, dural sac, spinal cord and peripheral nerves; the urinary tract; as well as valves within the blood vessels, blood, chambers or other parts of the heart, and/or other systems of the body. The anatomy may be a blood vessel, such as an artery or a vein of a patient's vascular system, including cardiac vasculature, peripheral vasculature, neural vasculature, renal vasculature, and/or any other suitable lumen inside the body. In addition to natural structures, the ultrasound probe <NUM> may be used to examine man-made structures such as, but without limitation, heart valves, stents, shunts, filters and other devices.

The transducer array <NUM> is configured to emit ultrasound signals, and receive ultrasound echo signals corresponding to the emitted ultrasound signals. The echo signals are reflections of the ultrasound signals from anatomy with the subject's body. The ultrasound echo signals may be processed by the electronic circuitry <NUM> in the ultrasound probe <NUM> and/or in the console <NUM> to generate ultrasound images. The transducer array <NUM> is part of the imaging assembly of the ultrasound probe <NUM>, including an acoustic window/lens and a matching material on a transmitting side of the transducer array <NUM>, and an acoustic backing material on a backside of the transducer array <NUM>. The acoustic window and the matching material have acoustic properties that facilitate propagation of ultrasound energy in desired directions (e.g., outwards, into the body of the patient) from the transmitting side of the transducer array <NUM>. The backing material has acoustic properties that impede or limit propagation of ultrasound energy in undesired directions (e.g., inwards, away from the body of the patient) from the backside of the transducer array <NUM>.

The transducer array <NUM> may include any number of transducer elements. For example, the array can include between <NUM> acoustic element and <NUM> acoustic elements, including values such as <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, <NUM> acoustic elements, and/or other values both larger and smaller. The transducer elements of the transducer array <NUM> may be arranged in any suitable configuration, such as a linear array, a planar array, a curved array, a curvilinear array, a circumferential array, an annular array, a phased array, a matrix array, a one-dimensional (1D) array, a <NUM>. x dimensional array (e.g., a <NUM>. 5D array), or a two-dimensional (2D) array. The array of transducer elements (e.g., arranged in one or more rows, one or more columns, and/or one or more orientations) can be uniformly or independently controlled and activated. The transducer array <NUM> can be configured to obtain one-dimensional, two-dimensional, and/or three-dimensional images of patient anatomy. The ultrasound transducer elements may be piezoelectric/piezoresistive elements, piezoelectric micromachined ultrasound transducer (PMUT) elements, capacitive micromachined ultrasound transducer (CMUT) elements, and/or any other suitable type of ultrasound transducer elements.

The transducer array <NUM> is in communication with (e.g., electrically coupled to) the electronic circuitry <NUM>. The electronic circuitry <NUM> can be any suitable passive or active electronic components, including integrated circuits (ICs), for controlling the transducer array <NUM> to obtain ultrasound imaging data and/or processing the obtained ultrasound imaging data or one or more printed control boards (PCBs). For example, the electronic circuitry <NUM> can include one or more transducer control logic dies. The electronic circuitry <NUM> can include one or more application specific integrated circuits (ASICs). In some embodiments, one or more of the ICs can comprise a microbeamformer (µBF), an acquisition controller, a transceiver, a power circuit, a multiplexer circuit (MUX), etc. In some embodiments, the electronic circuitry <NUM> can include a processor, a memory, a gyroscope, and/or an accelerometer. The electronic circuitry <NUM> may include a PCB <NUM> as shown. Various electrical components <NUM>, including but not limited to resistors, capacitors, transistors, any of the components previously mentioned, or any other electrical components may be mounted to the PCB. The electronic circuitry <NUM> including the PCB <NUM> and electrical components <NUM> are disposed within the ultrasound probe <NUM> and surrounded by the housing <NUM>.

The ultrasound probe <NUM> includes a cable <NUM> to provide signal communication between the console <NUM> and one or more components of the ultrasound probe <NUM> (e.g., the transducer array <NUM> and/or the electronic circuitry <NUM>). The cable <NUM> includes multiple electrical conductors <NUM> configured to carry electrical signals between the console <NUM> and the ultrasound probe <NUM>. The electrical conductors <NUM> can be bare wires surrounded by one or more layers of insulating materials. The insulating materials are typically polymer-based composites, nylon, and/or polyvinyl chloride (PVC) synthetic plastic polymer. In some embodiments, the conductors may be coaxial. The coaxial structures may use PTFE or expanded PTFE inner dielectrics and outer dielectrics of PET or PTFE. For example, electrical signals representative of the imaging data obtained by the transducer array <NUM> can be transmitted from the ultrasound probe <NUM> to the console <NUM> via the electrical conductors <NUM>. Control signals and/or power can be transmitted from the console <NUM> to the ultrasound probe <NUM> via the electrical conductors <NUM>. The cable <NUM> and/or electrical conductors <NUM> may provide any type of wired connection, such as a proprietary connection, an Ethernet connection, a Universal Serial Bus (USB) connection of any version or a mini USB of any version.

The cable <NUM> can also include a conduit <NUM> surrounding the electrical conductors <NUM>. The conduit <NUM> is shaped as a tube and used to protect and route the electrical conductors <NUM> in the cable <NUM> of the ultrasound imaging device <NUM>. The conduit <NUM> can be flexible and made of polymer, plastic, metal, fiber, other suitable materials, and/or combinations thereof. The conduit <NUM> protects the electrical conductors <NUM> by preventing their direct exposure to outside elements. A distal portion <NUM> of the cable <NUM> is coupled to the proximal portion <NUM> of the housing <NUM> of the ultrasound probe <NUM>.

A connector <NUM> is located at a proximal portion <NUM> of the cable <NUM>. The connector <NUM> is configured for removably coupling with the console <NUM>. Signal communication between the ultrasound probe <NUM> and the console <NUM> is established when the connector <NUM> is received within a receptacle <NUM> of the console <NUM>. In that regard, the ultrasound probe <NUM> can be electrically and/or mechanically coupled to the console <NUM>. The console <NUM> can be referenced as a computer or a computing device in some instances. The console <NUM> includes a user interface <NUM> and a display <NUM>. The console <NUM> is configured to process the ultrasound imaging data obtained by the ultrasound probe <NUM> to generate an ultrasound image and output the ultrasound image on the display <NUM>. A user can control various aspects of acquiring ultrasound imaging data by the ultrasound probe <NUM> and/or display of ultrasound images by providing inputs at the user interface <NUM>. The imaging device <NUM> and the display <NUM> may be communicatively coupled directly or indirectly to the console <NUM>.

One or more image processing steps can be completed by the console <NUM> and/or the ultrasound probe <NUM>. The console <NUM> and/or the ultrasound probe <NUM> can include one or more processors in communication with memory. The processor may be an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a central processing unit (CPU), a digital signal processor (DSP), another hardware device, a firmware device, or any combination thereof configured to perform the operations described herein. In some embodiments, the memory is a random access memory (RAM). In other embodiments, the memory is a cache memory (e.g., a cache memory of the processor), magneto-resistive RAM (MRAM), read-only memory (ROM), programmable read-only memory (PROM), erasable programmable read only memory (EPROM), electrically erasable programmable read only memory (EEPROM), flash memory, solid state memory device, hard disk drives, other forms of volatile and non-volatile memory, or a combination of different types of memory. In some embodiments, the memory may include a non-transitory computer-readable medium. The memory may store instructions. The instructions may include instructions that, when executed by a processor, cause the processor to perform operations described herein.

While the console <NUM> is a movable cart in the illustrated embodiment of <FIG>, it is understood that the console <NUM> can be a mobile device (e.g., a smart phone, a tablet, a laptop, or a personal digital assistant (PDA)) with integrated processor(s), memory, and display. For example, a touchscreen of the mobile device can be the user interface <NUM> and the display <NUM>.

<FIG> is a partially transparent perspective view of an ultrasound probe <NUM>, according to aspects to aspects of the present disclosure. <FIG> depicts exemplary embodiments of the transducer array <NUM>, the probe housing <NUM>, and the electronic circuitry <NUM> previously described with reference to <FIG>. In addition, <FIG> depicts an acoustic backing material <NUM>, a heatsink <NUM>, a heat pipe <NUM>, and a spacer <NUM>.

As shown in <FIG>, the transducer array <NUM> may be disposed at the distal portion <NUM> of the probe housing <NUM> near the distal end <NUM> and may be of any suitable type as described with reference to <FIG>. The housing <NUM> also includes a proximal region <NUM> and proximal end <NUM> as shown. The acoustic backing material <NUM> may be disposed proximal to the transducer array <NUM> and distal to the heatsink <NUM>. One purpose of the acoustic backing material is to absorb acoustic energy generated by the transducer array <NUM>, which may propagate in a proximal direction from the transducer array <NUM>. Additional features of the acoustic backing material <NUM> will be described with more detail with reference to <FIG> hereafter.

The probe housing <NUM> may include multiple portions. For example, as shown in <FIG>, the housing <NUM> may include two portions, a housing portion 110a, shown as a partially transparent component in <FIG>, and a housing portion 110b, shown as a solid component in <FIG> and positioned opposite the portion 110a.

The heatsink <NUM> may be positioned proximal to the acoustic backing material <NUM>. The heatsink <NUM> may be disposed in the housing <NUM> such that it is positioned near the transducer array <NUM>. A purpose of the heatsink <NUM> is to absorb heat generated by the transducer array <NUM> and/or the backing material <NUM>, and dissipate that heat to other portions of the probe <NUM> as will be discussed with more detail hereafter. In some embodiments, the transducer array <NUM> may be constructed of piezo-electric crystals to produce acoustic energy. These piezo-electric crystals may also generate heat which may be transmitted to a patient's body in excess of regulatory limits on the permissible temperatures of ultrasound probes. The transducer array <NUM> can be a source of heat within the probe <NUM>. In many applications, the transducer array <NUM> itself may not be constructed of thermally conductive materials. In addition, other components within the probe, such as an acoustic lens or other materials relating to the transducer array <NUM>, may be constructed of materials that are not thermally conductive (e.g. polymers or ceramics). The heatsink <NUM> may, therefore, be constructed of a thermally conductive material and may more efficiently dissipate heat away from the transducer array <NUM> before the probe temperature reaches disallowed levels.

In general, the heat pipe <NUM> transmits heat away from the heat source(s), such as the transducer array <NUM> and/or the acoustic backing material <NUM>, at the distal portion <NUM> and/or the distal end <NUM> of the probe housing <NUM>. The heat pipe <NUM> shown in <FIG> may include a distal portion <NUM> and a proximal portion <NUM>. The heat pipe <NUM> may also be referred to as a thermal pipe. The distal portion <NUM> of the heat pipe <NUM> is mechanically and thermally coupled to the heatsink <NUM>. The proximal portion <NUM> of the heat pipe <NUM> is mechanically and thermally coupled to a heat spreader material within the housing <NUM> as will be described with more detail hereafter. A purpose of the heat pipe <NUM> is to efficiently transfer heat from the heatsink <NUM> to the heat spreader material. As shown, the heat pipe <NUM> may be formed in a bent shape to make space for or avoid other components within the housing <NUM> such as the circuitry <NUM>, the PCB <NUM> or electrical components <NUM>. In some embodiments, the heat pipe <NUM> may be shaped in such a way to bend around one or more fastener structures such as screw receivers <NUM> or other structures, parts, or components within the housing <NUM>.

The spacer <NUM> may be disposed within the housing <NUM> near the proximal portion <NUM> of the heat pipe <NUM> and may urge the proximal portion <NUM> of the heat pipe <NUM> into contact with the heat spreader material which may be positioned on the inner surface of the housing <NUM>. Additional aspects of the spacer <NUM>, as well as the heat spreader material, will be described in more detail hereafter.

It is noted that the probe <NUM> may include any suitable number of heat pipes <NUM> in addition to the heat pipe <NUM> shown in <FIG>. For example, one additional heat pipe <NUM> may be positioned within the probe <NUM> of a similar shape as the heat pipe <NUM> shown. This additional heat pipe <NUM> may be positioned on the opposite side of the electronic circuitry <NUM> shown and will be discussed with more detail with reference to <FIG>. It will be apparent that, in additional embodiments, additional heat pipes <NUM> may be positioned in contact with both the heatsink <NUM> and the heat spreader material by altering various geometries, placements, and/or configurations of various components within the housing <NUM>. Any heat pipe <NUM> shown or described may also be of any suitable shape.

<FIG> is a diagrammatic cross-sectional side view of the ultrasound probe <NUM>, according to aspects of the present disclosure. The view of the ultrasound probe <NUM> in <FIG> is along a plane defined by the x-axis and the z-axis. <FIG> depicts the acoustic backing material <NUM> and the heatsink <NUM> including a heatsink body <NUM> and heatsink fins <NUM>. <FIG> additionally depicts the transducer array <NUM>, an acoustic lens <NUM>, the heat pipes <NUM> extending within the interior of the probe housing <NUM>, the spacer <NUM>, a mounting bracket <NUM>, and a machine screw <NUM>. A coordinate system indicator <NUM> is also shown. The indicator <NUM> indicates the x-axis and the z-axis.

The acoustic backing material <NUM> may be disposed on the backside of the transducer array <NUM> of acoustic elements. The acoustic backing material <NUM> may additionally be referred to as absorptive material, acoustic insulating material, or any other suitable term. The backing material <NUM> may be selected to absorb acoustic energy generated by the transducer array <NUM>. In this way, the backing material <NUM> may prevent acoustic energy from propagating in a direction proximal to the transducer array <NUM> and/or prevent acoustic energy that may be received by the transducer array <NUM> from a proximal direction, resulting in more accurate ultrasound data. The acoustic backing material may be constructed of any suitable material including but not limited to epoxy or thermoplastic resins with or without fillers to enhance dissipation of ultrasonic energy. In some embodiments, because the acoustic backing material <NUM> is positioned directly adjacent to the transducer array <NUM>, the material <NUM> may conform to a similar shape as the transducer array <NUM> but may also be of any suitable shape or size. In some embodiments, heat may also be generated by interaction between sound waves and the acoustic backing material <NUM>, such that the acoustic backing material <NUM> can be a source of heat within the probe <NUM>.

The backing material <NUM> is positioned distal to the heatsink <NUM>, as shown. The heatsink <NUM> may additionally be referred to as a dissipater. The heatsink <NUM> may also be of any suitable shape or size. The heatsink <NUM> may be constructed of a thermally conductive material and can be a non-metal, metal, or metal alloy, such as silver, copper, gold, aluminum nitride, silicon carbide, aluminum, tungsten, graphite, zinc, other suitable materials, and/or combinations thereof. Given the high thermal conductivity of the heatsink <NUM>, the heatsink may efficiently transfer heat from the transducer array <NUM> to the heat pipes <NUM>.

In some embodiments, the heatsink <NUM> may include a body <NUM> and a number of fins <NUM>. The heatsink body <NUM> has a proximal region <NUM> and a distal region <NUM>. The fins <NUM> may extend from the distal region <NUM> of the body <NUM>. The heatsink <NUM> may include any suitable number of fins <NUM>. The fins <NUM> may also be of any suitable shape, pattern, length, or may extend from the body <NUM> according to any suitable path. In some embodiments, the fins <NUM> may extend distally from the heatsink body <NUM> towards the transducer array <NUM>. For example, the fins <NUM> may be placed between the transducer array <NUM> and the heatsink body <NUM>. The set of fins <NUM> of the heatsink <NUM> may be embedded within the acoustic backing material <NUM> as shown in <FIG>. The acoustic backing material <NUM> may surround each of the fins <NUM> such that every exterior point of the fins <NUM> are in contact with the acoustic backing material. In some embodiments, the acoustic backing material <NUM> may be a resin that is cast on the fins <NUM>.

Because the effectiveness of the heatsink <NUM> depends on both the distance between the heatsink fins <NUM> and the transducer array and the length of the heatsink fins <NUM> themselves, the acoustic backing material <NUM> may be selected to be of a highly attenuative material. For example, the attenuation of the acoustic backing material <NUM> may be at least <NUM> dB/mm or greater than <NUM> dB/mm. By using a highly attenuative material for the acoustic backing material <NUM>, less material <NUM> is needed to sufficiently attenuate unwanted acoustic energy and the layer of material <NUM> between the transducer array <NUM> and the heatsink body may be thinner. A thinner layer of backing material <NUM> allows for shorter, and therefore more effective, heatsink fins <NUM>. These shorter fins <NUM> reduce thermal resistance between the heat source (e.g. the transducer array <NUM>) and the body <NUM> of the heatsink <NUM>. The fins <NUM> of the heatsink <NUM> may be spaced from the transducer array <NUM> by some distance. The fins <NUM> may be positioned very close to the transducer array <NUM> to optimize heat dissipation from the transducer array <NUM>. For example, the distal ends of the fins <NUM> may be positioned within <NUM> or less of the transducer array <NUM>.

As shown in <FIG>, the body <NUM> of the heat sink <NUM> may include a curved upper portion <NUM>. The distal edge of this curved upper portion <NUM> may be of substantially the same curvature as the transducer array <NUM> and acoustic lens <NUM> of the probe <NUM>. <FIG> additionally depicts fins <NUM> extending distally from the curved upper portion <NUM> within the backing material <NUM>.

<FIG> additionally depicts the heat pipes <NUM>. The heat pipes <NUM> may be configured to drain heat from the device <NUM>. A cross section of the distal portion <NUM> of each heat pipe <NUM> is shown adjacent to the proximal region <NUM> of the heatsink body <NUM> and may be in physical and/or thermal contact with the heatsink <NUM>. A thermal interface material <NUM> may be disposed between the distal portion <NUM> of the heat pipes <NUM> and the proximal region <NUM> of the heat sink <NUM>. Like the heatsink <NUM>, the heat pipes <NUM> may also be constructed of a thermally conductive material. For example, the heat pipes <NUM> may be constructed of aluminum or copper with water or ammonia as the working fluid. Additionally, the heat pipes <NUM> may include various components and/or structures. For example, in some embodiments, the heat pipes <NUM> may each include an envelope forming the exterior of the heat pipe <NUM> and constructed of a highly thermally conductive material. The envelope may enclose a wick structure and a working fluid. The wick structure may be affixed to the inner walls of the envelope and may absorb and distribute the working fluid along the heat pipe. The wick may be constructed of any suitable material and may be porous metal structure including, but not limited to copper, aluminum, or other materials. The working fluid in the heat pipes <NUM> may be distilled water. In other embodiments, the working fluid may alternatively be ammonia, nitrogen, acetone, methanol, methylamine, pentane, propylene, or any other suitable working fluids.

The heat pipes <NUM> may be shaped in such a way so that the distal region <NUM> of the heat pipes <NUM> are physically and/or thermally coupled to the proximal portion <NUM> of the heatsink <NUM>, as shown in <FIG>. Additional features and aspects of the shape and positioning of the heat pipes <NUM> will be described in more detail with reference to <FIG> and <FIG>. However, as shown in <FIG>, the distal portion <NUM> of the heat pipes <NUM> may be brought into physical contact with the proximal portion <NUM> of the heatsink <NUM> by a mounting bracket <NUM>. The mounting bracket <NUM> may be shaped so as to allow a space through which the heat pipes <NUM> may extend proximate to the heat sink body <NUM>. The heat pipes <NUM> may therefore be brought into contact with the heatsink <NUM> and then the mounting bracket <NUM> may be placed over the heat pipes and secured to the heatsink <NUM> via one or more machine screws <NUM>. The heatsink <NUM> may include one or more threaded holes into which the one or more machine screws <NUM> may be received and tightened bringing the mounting bracket <NUM> into firm contact with the heat pipes <NUM> and/or the heatsink <NUM> and securing or coupling the heat pipes <NUM> to the heatsink <NUM>. The mounting bracket <NUM> may be constructed of the same material as the heatsink <NUM> and/or the heat pipes <NUM> or may be constructed of a different material.

In some embodiments, the heat pipes <NUM> may be additionally or alternatively coupled to the heatsink <NUM> via soldering or a thermally conductive epoxy. In some embodiments, the bracket <NUM> may be omitted. The heat pipes <NUM> may be both mechanically and thermally coupled to the heatsink <NUM> and/or the bracket <NUM>. In such an embodiment, the solder or thermally conductive epoxy may completely surround the outer surface of the distal portion <NUM> of the heat pipes <NUM> or may be in contact with only a portion of the heat pipes <NUM>. In some embodiments, a thermal interface material may also be positioned between the heat pipes <NUM> and the heatsink <NUM> as will be described in more detail with reference to <FIG>.

At their proximal portion <NUM>, the heat pipes <NUM> may be pushed outward, or away from the centerline or central longitudinal axis of the probe <NUM> by the spacers <NUM> shown in <FIG>. For example, in some embodiments, the proximal region <NUM> of the heat pipes <NUM> may gradually slope outward towards the housing <NUM> as the heat pipes <NUM> extend away from the heatsink <NUM>. The spacers <NUM> may bring the proximal portion <NUM> of the heat pipes <NUM> into physical and/or thermal contact with the inner surface of the housing <NUM> and/or a heat spreader material on the inner surface of the housing <NUM>. The spacers <NUM> may include an inner surface <NUM> positioned facing the centerline of the probe <NUM> and an outer surface <NUM> facing the exterior of the probe <NUM>. The spacers <NUM> may be positioned in such a way that the heat pipes <NUM> are positioned at a distance from the PCB <NUM> and electronic components <NUM> as shown. In this way, the inner surface <NUM> of the spacer <NUM> may be in physical contact with the PCB <NUM> and electronic components <NUM> mounted to the PCB <NUM>. The outer surface <NUM> of the spacers <NUM> may be in physical contact with the heat pipes <NUM>. In this way, the spacers <NUM> separate the heat pipes <NUM> from the PCB <NUM> and electronic components <NUM>.

<FIG> is a diagrammatic cross-sectional front or back view the ultrasound probe <NUM>, according to aspects of the present disclosure. <FIG> will be described in connection with <FIG> which is a diagrammatic cross-sectional front or back view of the ultrasound probe <NUM>, according to aspects of the present disclosure. The view of the ultrasound probe <NUM> in <FIG> and <FIG> are along a plane defined by the x-axis and the y-axis. <FIG> depicts a distal region <NUM> of the probe <NUM> and shows, among other components, the acoustic lens <NUM>, the transducer array <NUM>, acoustic backing material <NUM>, the heatsink <NUM>, thermal interface material <NUM>, a heat pipe <NUM> with several different regions, the screw receiver <NUM>, the mounting bracket <NUM>, machine screws <NUM>, circuitry <NUM> including the PCB <NUM> and electronic components <NUM>, and the housing <NUM>.

As shown in <FIG>, the body <NUM> of the heatsink <NUM> has a proximal region <NUM> and a distal or curved region <NUM>. The fins <NUM> may extend from the distal region <NUM> of the curved region <NUM> into the acoustic backing material <NUM> and may form a curved profile as shown by the curved dotted lines in <FIG>. In other embodiments, the transducer array <NUM> may not form a curved profile. For example, as mentioned with reference to <FIG>, the transducer array <NUM> may be linear or planar. In such embodiments, the heatsink <NUM> and heatsink fins <NUM> may not be curved but may be positioned close to the transducer array <NUM> and may be of a linear or planar profile.

A thermal interface material <NUM> may be positioned between the proximal portion <NUM> of the heatsink <NUM> and the distal outer surface of the heat pipe <NUM>, as shown. This thermal interface material <NUM> may also be referred to as a film. The material <NUM> may be a silicon-based material or any other suitable material. In some embodiments, the thermal interface material may include commercially available materials such as <NUM> Tape <NUM>, Berquist HF300P-<NUM>-<NUM>-<NUM>/<NUM>, or other materials. In some embodiments, the material <NUM> may be a cure-in-place material. The material <NUM> may be a die cut graphite sheet. The material <NUM> may be pliable and may ensure that the heatsink <NUM> and heat pipe <NUM> are brought into good thermal contact. The material <NUM> may also minimize air gaps between the surface of the heatsink <NUM> and the heat pipe <NUM>. With relation to the heatsink <NUM>, the thermal interface material <NUM> may be positioned on the opposite side of the heatsink <NUM> as the fins <NUM> of the heatsink <NUM>.

As shown in <FIG>, the heat pipe <NUM> may include a region <NUM>, a region <NUM>, a region <NUM>, and a region <NUM>. The distal portion <NUM> of the heat pipe <NUM> between region <NUM> and region <NUM> may extend along a surface of the heatsink <NUM>. Along this distal portion <NUM>, the heat pipe <NUM> is of a flattened profile to maximize the surface area of the heat pipe <NUM> in contact with the heatsink <NUM> and/or the thermal interface material <NUM> to optimize heat transfer at this transition point. As shown in <FIG>, the cross-sectional shape of the heat pipe <NUM> along this portion between region <NUM> and region <NUM> may be an oval shape with flat top and bottom surfaces. In other embodiments, the cross-sectional shape may differ.

At the region <NUM>, the heat pipe <NUM> may curve away from the heatsink <NUM>. The heat pipe <NUM> may then curve around other components such as circuitry <NUM> or other structures or components within the probe <NUM>. Along this curved or central portion <NUM> between region <NUM> and region <NUM>, the heat pipe <NUM> is not flattened. The cross-sectional shape of the heat pipe <NUM> may be substantially circular from the region <NUM> to the region <NUM>. The cross-sectional shape may also differ. Because the cross-sectional shape of the heat pipe <NUM> is circular at the central region <NUM>, the surface area of the central portion <NUM> is less than the surface area of the heat pipes <NUM> at either the distal region <NUM> or the proximal region <NUM>.

From the region <NUM> to the region <NUM> and extending along the proximal portion <NUM> of the heat pipe to the region <NUM> shown in <FIG>, the heat pipe <NUM> may be of a flattened profile similar to the distal region <NUM> extending from region <NUM> to region <NUM>. For example, the cross-sectional shape of the heat pipe <NUM> from region <NUM> to region <NUM> (<FIG>) may be a similar shape as the cross-sectional shape from the region <NUM> to region <NUM>, such as an oval with flat top and bottom surfaces, or any other suitable shape. This flattening from region <NUM> to region <NUM> (<FIG>) may maximize the surface area of the heat pipe <NUM> brought into contact with the heat spreader material and/or the inner wall of the housing <NUM> to optimize heat transfer at this junction.

The probe housing <NUM> may include an inner surface <NUM> and an outer surface <NUM> as shown in <FIG> and <FIG>. The heat spreader material <NUM> shown in <FIG> may be adhered to the inner surface <NUM> of the housing <NUM>. <FIG> also includes the coordinate system indicator <NUM> again indicating the x-axis and the y-axis. In some embodiments, the housing <NUM> may include two structures (e.g., two halves), portion 110a and portion 110b as described with reference to <FIG>, similar to the housing portion 110b shown in <FIG>, that are bonded together. The housing <NUM> may fully or partially enclose one or more of the components discussed herein. A heat spreader material <NUM> can be coupled to the inner surface of each housing portion that together forms the housing <NUM>. In this way, one of the heat pipes <NUM> shown in <FIG> may be in physical and/or thermal contact with one heat spreader material <NUM> of one housing structure and the other heat pipe <NUM> of <FIG> may be in physical and/or thermal contact with the other heat spreader material <NUM> of the other housing structure.

The heat spreader material <NUM> may be configured to efficiently dissipate heat. The element <NUM> may be constructed of a thermally conductive material such as a pyrolytic graphite sheet. The element <NUM> may also be constructed of any other suitable material such as copper, aluminum including for example aluminum <NUM>, or other materials which have high thermal conductivity, other suitable planar thermally conductive materials, and/or combinations thereof. The heat spreader material <NUM> may also be referred to as a heat spreader, a heat dissipater, a heat spreader material, or any other suitable term. The heat spreader material <NUM> may be laminated to the inner surface of the housing <NUM>. For example, an adhesive may be positioned on one side of the heat spreader material <NUM> that is placed in contact with the inner surface <NUM> of the housing portion 110a and/or 110b. The element <NUM> may be of any suitable size or shape. The element <NUM> may follow the inner contours of the housing <NUM>. The element <NUM> may be configured to be as large as possible, or to be in contact with the most surface area of the housing <NUM> inner surface as possible to optimize heat transfer from the element <NUM> to the housing <NUM> and subsequently to the outside environment.

A thermal interface material <NUM> may be placed between the proximal region <NUM> of the heat pipe <NUM> and the heat spreader material <NUM> with which the pipe <NUM> is brought into physical and/or thermal contact. In some embodiments, this thermal interface material <NUM> is a thermally conductive and facilitates heat transfer between the heat pipe <NUM> and the heat spreader material <NUM> similar to how the thermal interface material <NUM> described with reference to <FIG> facilitates heat transfer between the distal portion <NUM> of the heat pipe <NUM> and the proximal portion <NUM> of the heatsink <NUM>. In some embodiments, the thermal interface material <NUM> may be substantially similar to the thermal interface material <NUM>. In other embodiments, the thermal interface <NUM> may differ from the thermal interface material <NUM>. The thermal interface material <NUM> and/or <NUM> may also be referred to as gap filling paste, thermal interface paste, gap filling material, filler material, interface material, or any other suitable term.

In some embodiments, the thermal interface material <NUM> can be a gap filling paste applied between the proximal portion <NUM> of the heat pipe <NUM> (e.g. from the region <NUM> of the pipe <NUM> to the region <NUM>) and the heat spreader material <NUM>. The thermal interface material <NUM> may be thermally conductive. In some embodiments, the material <NUM> may have adhesive properties to secure the proximal portion <NUM> of the heat pipe <NUM> to the heat spreader material <NUM>. In some embodiments, after the spacers <NUM> are positioned adjacent to the heat pipes <NUM> during assembly and before the housing structures 110a and 110b are seated together to enclose the inner components, the spacers <NUM> may force the proximal region <NUM> of the heat pipes <NUM> outward such that they protrude outward along the z-axis farther than the housing <NUM> would permit. As a result, the act of seating the two structures 110a and 110b of the housing <NUM> on the assembly pushes the proximal region <NUM> of the heat pipes inward along the z-axis and compresses the spacers <NUM>, thus applying pressure to the heat pipes <NUM> and forming secure contact with the heat spreaders <NUM>. As the spacers <NUM> force the proximal region <NUM> of the heat pipes <NUM> into tighter contact with the heat spreader material <NUM>, the thermal interface paste <NUM> flows and displaces resulting in a large area over which the proximal region <NUM> of the heat pipes <NUM> may contact with the pyrolytic heat spreaders <NUM>. One purpose of the thermal interface material <NUM> may be to fill any air gaps between the heat pipes <NUM> and the spreaders <NUM> to maximize thermal transfer. Any suitable amount of thermal interface material <NUM> may be positioned between the pipes <NUM> and spreaders <NUM>. In some embodiments, approximately <NUM>-<NUM> of thermal interface material is positioned between the proximal portion <NUM> of the pipes <NUM> and the heat spreaders <NUM>.

<FIG> additionally depicts the spacer <NUM> mentioned previously. As shown in <FIG>, one spacer <NUM> may be placed on the inner side of the proximal portion <NUM> of each of the heat pipes <NUM>. In this way, a single heat pipe may be positioned between one spacer <NUM> and one heat spreader <NUM>. In some embodiments, a spacer <NUM> may include two separate structures. The thickness of the spacer <NUM> may be of a minimum thickness at the distal region <NUM> of the spacer <NUM> and may increase in thickness extending in a proximal direction such that the spacer is of a maximum thickness at the proximal region <NUM> of the spacer <NUM>. In this way, the spacer <NUM> may form a wedge-shaped structure. In any configuration, the spacer <NUM> may urge the proximal portion <NUM> of the heat pipe <NUM> closer to the inner surface of the housing <NUM> than the central portion <NUM> of the heat pipe <NUM>. The central portion <NUM> may also be referred to as a curved portion.

<FIG> is a diagrammatic perspective view of a portion of an ultrasound probe housing <NUM>, according to aspects of the present disclosure. <FIG> shows one structure which may be included in the housing <NUM> of the probe <NUM>, or may be one half of the structure that forms the housing <NUM>. Shown adhered to the inner surface of the housing <NUM> is a heat spreader material <NUM>. As previously mentioned, the heat spreader material <NUM> may be laminated to the inner surface of the housing <NUM> or may be adhered by any other suitable means. The spreader <NUM> may be configured to maximize the surface area of contact between the spreader <NUM> and the inner surface of the housing <NUM> and may therefore extend along as much of the inner surface of the housing <NUM> as possible. The outer surface of the housing <NUM> shown may be configured to be grasped by a user of the ultrasound system <NUM>.

The heat spreader film <NUM> may be die cut from bulk pyrolytic graphite sheet (PGS) having an integral pressure sensitive adhesive (PSA) on one face and a protective PET film laminated to the other face. The heat spreader <NUM> shape and relief cuts may be configured to maximize the surface area contact with the inner surface of the transducer housing <NUM>. One heat spreader <NUM> may be applied to the inner surface of both the left and right housing halves <NUM> in such a way to eliminate or minimize wrinkles while maximizing wetted area to the housing <NUM>.

To supplement the EMI RFI shield of the transducer probe <NUM>, the PGS sheet of the heat spreader <NUM> may be connected to electrical shield potential by metallizing inner surfaces of the transducer housing using conductive paint or metal plating and utilizing an electrically conductive PSA adhesive on the PGS film. The housing <NUM> may form an electric and/or magnetic shield for the electronics <NUM> in the probe <NUM>. This shield may include various conductive components positioned along the inner or outer surfaces of the housing <NUM>. This shield may prevent various electromagnetic or radiofrequency signals from altering performance of various components within the probe <NUM>. In some embodiments, the PGS sheet of the heat spreader <NUM> may be integrated into or be a component of this shield. In some embodiments, the heat spreader may be a die formed metal foil.

In some embodiments, the heat spreader material <NUM> may be attached to the inner surface of the housing <NUM> utilizing an electrically conductive PSA adhesive that allows the PGS to be part of the EMI RFI shielding circuit. In other embodiments, the heat spreader material <NUM> may not be attached with an electrically conductive PSA adhesive. Rather, a thin, soft, non-electrically conductive adhesive may be used. A thin non-electrically conductive adhesive may still permit electrical contact between the PGS sheet and the conductive coating and/plating on the inner surface of the housing (part of EMI RFI shielding circuit) when the PGS film is well wetted to the housing. The inner surface of the housing <NUM> may additionally include a metallized portion forming a shield for the electronics <NUM> within the probe <NUM> against electromagnetic interference and/or radiofrequency interference. The heat spreader <NUM> may be in electrical communication with this metallized portion of the housing <NUM>. This may be done with the electrically conductive adhesive or by any other suitable means. Once the heat spreader <NUM> is adhered to the housing <NUM>, the heat spreader <NUM> may form a portion of the electromagnetic shield. In some embodiments, the heat spreader material <NUM> may be a single sheet of material or may be many sheets of material. Several sheets may completely or partially overlap to form the heat spreader material <NUM>.

<FIG> is a schematic diagram of the thermal path <NUM> through which heat may dissipate from the ultrasound probe <NUM>, according to aspects of the present disclosure. It is noted that any of the components or steps along the thermal path <NUM> described may be modified and/or combined with other steps.

Heat may be generated by the transducer array <NUM>, matching layers, the acoustic lens <NUM>, acoustic backing material <NUM>, or various other components within the probe <NUM>. The heat generated by the transducer array <NUM> may be partially absorbed by the acoustic backing material <NUM> positioned directly behind the transducer array <NUM>. The heat generated by the transducer array may then be transferred to the fins <NUM> of the heatsink <NUM>. The heat may then pass through the heatsink <NUM> and be transferred to the heat pipes <NUM> in physical and/or thermal contact with the heatsink <NUM> through the thermal interface material <NUM>. The heat may then pass through the heat pipes to the heat spreader material <NUM>. The heat may pass through a thermal interface material <NUM>. The heat may also or alternatively pass through a layer of thermal interface material as previously described with reference to <FIG>. The heat may then be transferred from the heat spreader material <NUM> to the inner surface and/or the outer surface of probe housing <NUM> and from there into the surrounding environment. In this way, heat is dissipated away from the distal surface of the ultrasound probe <NUM> and keep the temperature of the surface which may often be brought into physical contact with a patient's skin within any regulatory temperature limits.

Claim 1:
An ultrasound imaging device, comprising:
a housing (<NUM>) comprising an outer surface and an inner surface, wherein the outer surface is configured to be grasped by a user;
an array of acoustic elements (<NUM>) configured to transmit ultrasound energy and receive ultrasound echoes associated with the ultrasound energy, wherein the array of acoustic elements is disposed at an end of the housing (<NUM>);
a heat sink (<NUM>) disposed within the housing and configured to receive heat generated by the array of acoustic elements;
a heat pipe (<NUM>) disposed within the housing and configured to transmit the heat away from the end of the housing, wherein the heat pipe comprises a proximal portion (<NUM>) and a distal portion (<NUM>); and
a heat spreader material disposed on the inner surface of the housing (<NUM>) and configured to dissipate the heat,
wherein the distal portion (<NUM>) of the heat pipe (<NUM>) is in thermal contact with the heat sink (<NUM>) and the proximal portion (<NUM>) of the heat pipe is in thermal contact with the heat spreader material,
characterised in that
the heat pipe (<NUM>) comprises a central portion between the proximal portion and the distal portion, and wherein the proximal portion and the distal portion comprise a flattened cross-sectional profile with a larger surface area for thermal contact, and the central portion comprises a non-flattened cross-sectional profile with a smaller surface area for thermal contact.