A multi-chiplet intravascular ultrasound catheter tip

Abstract

An intravascular ultrasound (IVUS) probe is described. The IVUS probe can include electronic assemblies configured to at least partially surround a radial center at a distal end of the IVUS probe. Each IVUS electronic assembly can include a first chiplet configured to generate a high-voltage pulse based on a low-voltage transmission signal, a second chiplet configured to generate the low-voltage transmission signal and to process a low-voltage reception signal to reduce a number of channels of the low-voltage reception signal, an ultrasound transducer array and a substrate. The ultrasound transducer array can be configured to receive the high-voltage pulse from the first chiplet, generate an ultrasound signal based on the high-voltage pulse, and generate the low-voltage reception signal from ultrasound waves. A substrate can be coupled to the ultrasound transducer array, the first chiplet and the second chiplet.

Description

A MULTI-CHIPLET INTRAVASCULAR ULTRASOUND CATHETER TIPCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S Provisional Application Serial No. 63 / 518,540, filed August 9, 2023, entitled “A MULTI-CHIPLET INTRAVASCULAR ULTRASOUND CATHETER TIP,” which is incorporated by reference herein in its entirety. Any and all applications for which a foreign or domestic priority claim is identified in the Application Data Sheet as filed with the present application are hereby incorporated by reference under 37 CFR 1.57.BACKGROUNDTechnical Field

[0002] The present disclosure generally relates to an ultrasound transducer assembly, for example, an ultrasound transducer assembly comprising dual-chiplets on an intravascular ultrasound (“IVUS”) catheter.Description of Related Technology

[0003] Intravascular ultrasound (“IVUS”) catheters are widely used for diagnosing or assessing injured or diseased tissues or vessels, such as an artery within the human body to determine if further treatment is needed. As the IVUS catheter passes through the tissue or vessel, an ultrasonic transducer array disposed on the surface of the catheter can emit ultrasonic pulses and / or signals into the tissue or vessel and surrounding areas. Received signals can then be interpreted into images and / or streams of images used for treatment and diagnosis.SUMMARY

[0004] Various embodiments of systems, methods, and devices within the scope of the appended claims each have several aspects, no single one of which is solely responsible for the desirable attributes described herein. Without limiting the scope of the appended claims, some prominent features are described herein.

[0005] In some embodiments, the systems, methods, and devices described herein relate to an intravascular ultrasound (IVUS) probe located on a distal end of a catheter and configured to generate and process ultrasound signals. The IVUS probe caninclude a plurality of IVUS electronic assemblies configured to at least partially surround a radial center at the distal end of the IVUS probe. Each IVUS electronic assembly can include a first chiplet configured to generate a high-voltage pulse based on a low-voltage transmission signal. Each IVUS electronic assembly can include a second chiplet configured to generate the low-voltage transmission signal and to process a low-voltage reception signal to reduce a number of channels of the low-voltage reception signal. Each IVUS electronic assembly can include an ultrasound transducer array. The ultrasound transducer array can be configured to receive the high-voltage pulse from the first chiplet, generate an ultrasound signal based on the high-voltage pulse, and generate the low-voltage reception signal from ultrasound waves. Each IVUS electronic assembly can include a substrate configured to: couple to the ultrasound transducer array, the first chiplet and the second chiplet, and provide a signal path between the first chiplet and the second chiplet.

[0006] In some embodiments, the first chiplet is configured to provide the low- voltage reception signal to the second chiplet without processing the low-voltage reception signal. In some embodiments, the plurality of IVUS electronic assemblies fully surround the radial center at the distal end of the IVUS probe In some embodiments, the plurality of IVUS electronic assemblies include at least four ultrasound electronics assemblies. In some embodiments, the plurality of IVUS electronic assemblies include at least six ultrasound electronics assemblies. In some embodiments, the plurality of IVUS electronic assemblies include at least eight ultrasound electronics assemblies. In some embodiments, the substrate includes one or more high density routing dies. In some embodiments, the first chiplet, second chiplet, and the ultrasound transducer array are bonded to the substrate. In some embodiments, the first chiplet, the second chiplet. and the ultrasound transducer array are bonded to the substrate using die-to-die bonding. In some embodiments, the die-to-die bonding includes a plurality of conductive bumps. In some aspects, the techniques described herein relate to a IVUS probe, wherein the substrate includes an organic material. In some embodiments, the ultrasound transducer array includes a one dimensional array of ultrasonic transducer elements.

[0007] In some embodiments, the systems, methods, and devices described herein relate to a system for intravascular ultrasound (IVUS). The IVUS system can include a catheter adapted to be inserted into a body of a patient along a lumen. The IVUS system can include an IVUS probe position in a distal end of the catheter. The IVUS probe can include a plurality of IVUS electronic assemblies configured to at least partially surround a radial center of the IVUS probe. Each IVUS electronic assembly can include a first chipletconfigured to generate a high-voltage pulse based on a low-voltage transmission signal. Each IVUS electronic assembly can include a second chipl et configured to generate the low-voltage transmission signal and to process a low-voltage reception signal to reduce a number of channels of the low-voltage reception signal. Each IVUS electronic assembly can include an ultrasound transducer array. The ultrasound transducer array can be configured to receive the high-voltage pulse from the first chiplet, generate an ultrasound signal based on the high-voltage pulse, and generate the low-voltage reception signal from ultrasound waves. Each IVUS electronic assembly can include a substrate configured to: couple to the ultrasound transducer array, the first chiplet and the second chiplet, and provide a signal path between the first chiplet and the second chiplet.

[0008] In some embodiments, the first chiplet is configured to provide the low- voltage reception signal to the second chiplet without processing the low-voltage reception signal. In some embodiments, the plurality of IVUS electronic assemblies fully surround the radial center at the distal end of the IVUS probe In some embodiments, the plurality' of IVUS electronic assemblies include at least four ultrasound electronics assemblies. In some embodiments, the plurality' of IVUS electronic assemblies include at least six ultrasound electronics assemblies. In some embodiments, the plurality of IVUS electronic assemblies include at least eight ultrasound electronics assemblies. In some embodiments, the substrate includes one or more high density routing dies. In some embodiments, the first chiplet, second chiplet. and the ultrasound transducer array are bonded to the substrate. In some embodiments, the first chiplet, second chiplet, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding. In some embodiments, the die-to-die bonding includes a plurality of conductive bumps. In some embodiments, the substrate includes organic material. In some embodiments, the ultrasound transducer array includes a one dimensional array of ultrasonic transducer elements. In some embodiments, the IVUS system can further include a cable extending from the plurality of IVUS electronic assemblies towards a proximal end of the catheter. In some embodiments, the cable is configured to electrically connect the plurality of IVUS electronic assemblies to a controller configured to be disposed outside the body of the patient.

[0009] In some embodiments, the systems, methods, and devices described herein relate to a method of performing intravascular ultrasound (IVUS). The method can include providing an IVUS probe located on a distal end of a catheter and configured to generate and process ultrasound signals. The IVUS probe can include a plurality of IVUS electronic assemblies configured to at least partially surround a radial center at the distalend of the IVUS probe. Each IVUS electronic assembly can include a first chiplet configured to generate a high-voltage pulse based on a low-voltage transmission signal. Each IVUS electronic assembly can include a second chiplet configured to generate the low-voltage transmission signal and to process a low-voltage reception signal. Each IVUS electronic assembly can include an ultrasound transducer array. The ultrasound transducer array can be configured to receive the high-voltage pulse from the first chiplet, generate an ultrasound signal based on the high-voltage pulse, and generate the low-voltage reception signal from ultrasound waves. Each IVUS electronic assembly can include a substrate configured to couple to the ultrasound transducer array, the first chiplet and the second chiplet, and provide a signal path between the first chiplet and the second chiplet. The method can include generating the ultrasound signal while the IVUS probe is disposed within a body of a patient. The method can include generating the low-voltage reception signal. The method can include processing the low-voltage reception signal.

[0010] In some embodiments, the first chiplet is configured to provide the low- voltage reception signal to the second chiplet without processing the low-voltage reception signal. In some embodiments, the method can further include transmitting the processed low-voltage reception signals to a controller. In some embodiments, the substrate includes one or more high density routing dies. In some embodiments, the plurality7of IVUS electronic assemblies fully surround the radial center at the distal end of the IVUS probe. In some embodiments, the plurality of IVUS electronic assemblies include at least four ultrasound electronics assemblies. In some embodiments, the plurality of IVUS electronic assemblies include at least six ultrasound electronics assemblies. In some embodiments, the plurality of IVUS electronic assemblies include at least eight ultrasound electronics assemblies. In some embodiments, the first chiplet, second chiplet, and the ultrasound transducer array are bonded to the substrate. In some embodiments, the first chiplet, second chiplet, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding. In some embodiments, the die-to-die bonding includes a plurality' of conductive bumps. In some embodiments, the substrate includes an organic material. In some embodiments, the ultrasound transducer array includes a one dimensional array of ultrasonic transducer elements.

[0011] In some embodiments, the systems, methods, and devices described herein relate to an ultrasound catheter assembly. In some embodiments, the ultrasound catheter assembly includes a catheter adapted to be inserted into a body of a patient along a lumen, a proximal end of the catheter configured to be disposed outside the body of thepatient, a distal end of catheter configured to be inserted into the body of the patient; a round face on the distal end, defining a radial center; and a plurality of ultrasound electronics assemblies positioned in the distal end of the catheter, the plurality of ultrasound electronics assemblies at least partially surrounding the radial center of the round face on the distal end. In some embodiments, each of the plurality of ultrasound electronics assemblies include an ultrasound transducer array configured to: generate an ultrasound signal based on at least one of a first voltage signal or a second voltage signal, the first signal and the second signal being different from each other, transmit the ultrasound signal to an internal vascular vessel of the patient while the ultrasound transducer array is disposed within the body of the patient, and receive a return ultrasound signal returned from the internal vascular vessel of the patient; a first chip configured to generate and provide the first voltage signal to the ultrasound transducer array; a second chip configured to generate and provide the second voltage signal to the first chip; and a substrate configured to: accommodate the ultrasound transducer array, the first chip and the second chip, and provide a signal path between the first chip and second chip to electrically connect the first chip and second chip.

[0012] In some embodiments, the plurality of ultrasound electronics assemblies fully surround the radial center of the round face on the distal end. In some embodiments, the plurality of ultrasound electronics assemblies comprise at least four ultrasound electronics assemblies. In some embodiments, the plurality of ultrasound electronics assemblies comprise at least six ultrasound electronics assemblies. In some embodiments, the plurality of ultrasound electronics assemblies comprises at least eight ultrasound electronics assemblies. In some embodiments, at least two of the at least eight ultrasound electronics assemblies contact each other. In some embodiments, the substrate includes one or more high density routing dies. In some embodiments, the ultrasound catheter assembly includes a cable extending from the plurality of ultrasound electronics assemblies towards the proximal end of the catheter. In some embodiments, the cable is configured to electrically connect the plurality of ultrasound electronics assemblies to a controller configured to be disposed outside the body of the patient. In some embodiments, the first chip, second chip, and the ultrasound transducer array are bonded to the substrate. In some embodiments, the first chip, second chip, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding. In some embodiments, the die-to-die bonding includes a plurality of conductive bumps. In some embodiments, the substrate comprisesan organic material. In some embodiments, the ultrasound transducer array comprises a one dimensional (“ID”) array of ultrasonic transducer elements.

[0013] In some embodiments, the systems, methods, and devices described herein relate to an ultrasound transducer for use with a catheter. In some embodiments, the ultrasound transducer includes a plurality7of ultrasound electronics assemblies configured to be positioned in a distal end of a catheter and configured to be inserted into a body of a patient, each of the plurality of ultrasound electronics assemblies includes an ultrasound transducer array configured to: generate an ultrasound signal based on at least one of a first voltage signal or a second voltage signal, the first signal and the second signal being different from each other, the second voltage signal including at least a portion of a control signal received from a catheter controller, transmit the ultrasound signal to an internal vascular vessel of the patient while the ultrasound transducer array is disposed within the body of the patient, and receive a return ultrasound signal returned from the internal vascular vessel of the patient; a first chip configured to generate and provide the first voltage signal to the ultrasound transducer array; a second chip configured to generate and provide the second voltage signal to the first chip; and a substrate configured to: accommodate the ultrasound transducer array, the first chip and the second chip, and provide a signal path between the first chip and second chip to electrically connect the first chip and second chip.

[0014] In some embodiments, the plurality of ultrasound electronics assemblies comprise at least four ultrasound electronics assemblies. In some embodiments, the plurality7of ultrasound electronics assemblies comprise at least six ultrasound electronics assemblies. In some embodiments, the plurality7of ultrasound electronics assemblies comprise at least eight ultrasound electronics assemblies. In some embodiments, at least two of the at least eight ultrasound electronics assemblies contact each other. In some embodiments, the substrate includes one or more high density routing dies. In some embodiments, the first chip, second chip, and the ultrasound transducer array are bonded to the substrate. In some embodiments, the first chip, second chip, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding. In some embodiments, the die-to-die bonding includes a plurality7of conductive bumps. In some embodiments, the substrate comprises an organic material. In some embodiments, the ultrasound transducer array comprises a one dimensional (“ID”) array of ultrasonic transducer elements. In some embodiments, the controller is configured to be disposed outside the body of the patient.

[0015] In some embodiments, the systems, methods, and devices described herein relate to a method of using an ultrasound catheter assembly. In some embodiments, the method includes providing an ultrasound catheter assembly including: a catheter adapted to be inserted into a body of a patient along a lumen, a proximal end of the catheter configured to be disposed outside the body of the patient, and a distal end of catheter configured to be inserted into the body of the patient; a round face on the distal end, defining a radial center; a plurality of ultrasound electronics assemblies positioned in the distal end of the catheter, the plurality of ultrasound electronics assemblies at least partially surrounding the radial center of the round face on the distal end, each of the plurality of ultrasound electronics assemblies including: an ultrasound transducer array configured to: generate an ultrasound signal based on at least one of a first voltage signal or a second voltage signal, the first signal and the second signal being different from each other, transmit the ultrasound signal to an internal vascular vessel of the patient while the ultrasound transducer array is disposed within the body of the patient, and receive a return ultrasound signal returned from the internal vascular vessel of the patient; a first chip configured to generate and provide the first voltage signal to the ultrasound transducer array; a second chip configured to generate and provide the second voltage signal to the first chip; and a substrate configured to: accommodate the ultrasound transducer array, the first chip and the second chip, and provide a signal path between the first chip and second chip to electrically connect the first chip and second chip; generating ultrasound signals using the plurality of ultrasound electronics assemblies while the plurality of ultrasound electronics assemblies are disposed within the body of the patient; transmitting the ultrasound signals using the plurality ultrasound electronics assemblies toward the internal vascular vessel of the patient while the plurality of ultrasound electronics assemblies are disposed within the body of the patient; receiving ultrasound signals returned from the internal vascular vessel of the patient using the plurality' ultrasound electronics assemblies while the plurality' of ultrasound electronics assemblies are disposed within the body of the patient; and providing the returned ultrasound signals to a controller disposed outside the body of the patient.

[0016] In some embodiments, providing includes transmitting the returned ultrasound signals to the controller through one or more cables connected to the catheter. In some embodiments, the substrate includes one or more high density routing dies. In some embodiments, the plurality of ultrasound electronics assemblies fully surround the radial center of the round face on the distal end. In some embodiments, the plurality of ultrasoundelectronics assemblies comprise at least four ultrasound electronics assemblies. In some embodiments, the plurality of ultrasound electronics assemblies comprise at least six ultrasound electronics assemblies. In some embodiments, the plurality of ultrasound electronics assemblies comprise at least eight ultrasound electronics assemblies. In some embodiments, at least two of the at least eight ultrasound electronics assemblies contact each other. In some embodiments, the first chip, second chip, and the ultrasound transducer array are bonded to the substrate. In some embodiments, the first chip, second chip, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding. In some embodiments, the die-to-die bonding includes a plurality of conductive bumps. In some embodiments, the substrate comprises an organic material. In some embodiments, the ultrasound transducer array comprises a one dimensional C I D") array of ultrasonic transducer elements.BRIEF DESCRIPTION OF THE DRAWINGS

[0017] These and other features, aspects, and advantages of the present application are described with reference to drawings of certain embodiments, which are intended to illustrate, but not limit, the present disclosure. It is to be understood that the attached drawings are for the purpose of illustrating concepts disclosed in the present application and may not be to scale.

[0018] FIG. 1A illustrates a diagram of an example system for performing intravascular ultrasounds.

[0019] FIG. IB is a block diagram illustrating signal communication in an example system for performing intravascular ultrasounds

[0020] FIG. 2A is a cross section of a catheter tip illustrating an example configuration of an ultrasonic transducer assembly within a catheter tip.

[0021] FIG 2B is a perspective view of an example ultrasound electronics assembly.

[0022] FIGS. 3 A and 3B illustrate example flows of electric signal paths through an ultrasound electronics assembly.

[0023] FIG. 4A illustrates a process for generating an ultrasound signal based on a control signal.

[0024] FIG. 4B illustrates a process for generating and transmitting a sensor signal.

[0025] FIG. 5A and FIG. 5B illustrate perspective views of an alternative embodiments of an ultrasound electronics assembly.

[0026] FIG. 6 illustrates an example ultrasound transducer array that can be utilized in an ultrasound electronics assembly.

[0027] FIG. 7 illustrates a perspective view of an example high density routing die.

[0028] FIG. 8 is an example schematic diagram depicting a high-voltage chipl et used in a system for intravascular ultrasounds.

[0029] FIG. 9 is an example schematic diagram depicting a low-voltage chiplet used in a system for intravascular ultrasounds.

[0030] FIG. 10 illustrates a flow diagram of an example process for forming an ultrasonic transducer assembly.DETAILED DESCRIPTION OF CERTAIN INVENTIVE ASPECTS

[0031] In the following description, various examples will be described. For purposes of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the examples. However, it will also be apparent to one skilled in the art that the examples may be practiced without the specific details. Furthermore, well-known features may be omitted or simplified in order not to obscure the examples being described.

[0032] Generally described, aspects of the present disclosure relate to design and manufacture of ultrasound electronics assemblies which may be used in an intravascular ultrasound (“IVUS”) imaging (e.g.. in an IVUS imaging catheter system). More specifically, aspects of the present disclosure relate to utilization of at least one multi- chiplet assembly to control transmission and receipt of ultrasound pulses for IVUS. As will be described in more detail below, aspects of the present disclosure correspond to the use of separate chiplets (also referred to herein as “chips) for control of high voltage components and low-voltage components.

[0033] The voltage needed to drive the elements of a transducer array to produce ultrasound signals can be high relative to the other voltages used in ultrasound imaging. For example, the signal used to drive the transducer array (referred to herein as a “high-voltage signal’" or a “high-voltage pulse) can be between 10-60 Volts peak-to-peak (VPP). In some instances, an even higher voltage may be used (e.g., in some applications the high-voltage signal may reach or exceed 200 Vpp). In contrast, the signal the transducerarray produces (referred to herein as a “low-voltage reception signal”) when receiving ultrasound signals (such as returned and / or reflected ultrasound signals) can have a significantly attenuated voltage compared to the high-voltage signal. In some instances, the low-voltage reception signal may be in the order of magnitude of millivolts (mV) or microvolts (pV). For example, the low-voltage reception signal may range from 10 pV to 1.2 V. Some of the returned ultrasound signals (also referred to as “echoes”) may be reflected from more distant target or from a target with a low reflectivity. In some instances, the low-voltage reception signal associated with this target may be less than 10 pV. As such, multiple orders of magnitude may separate the voltages of the high-voltage signal and the low-voltage reception signal.

[0034] The circuitry used in generating the high-voltage signal may differ than the circuitry used in the rest of an ultrasound system. For instance, bipolar-CMOS-DMOS (BCD, where bipolar refers to bipolar junction transistors, CMOS refers to complementary metal-oxide-semiconductor transistors, and DMOS refers to double-diffused metal-oxide- semiconductor transistors) technology is often used for applications high-voltage applications (e.g., applications around or above 30 Volts (V)). The feature size of BCD technology can be larger than technology used in lower voltage contexts. For example, a ty pical feature size of BCD technology7used for applications above 30 V is approximately 65 nanometers (nm). The technology used in low voltage circuitry (such as the voltages of the low-voltage reception signal) may be smaller. For example. CMOS transistors often have feature sizes of 7 nm and, in some instances, have feature sizes of 5 nm or smaller. The smaller feature sizes can allow for increased transistor density7, reducing the overall size of the semiconductor chiplets the transistors are implemented on.

[0035] Described herein is an electronic assembly for use in an ultrasound imaging, such as IVUS imaging. The electronic assembly includes separate chiplets for high-voltage and low-voltage components. Advantageously, the separated high-voltage and low-voltage components may reduce critical size dimensions of the electronic assembly. For example, the described electronic assembly may have a reduced overall size, increasing the suitability' for IVUS applications, which require the electronic assembly to be inserted and traverse vessels of a patient. Further, the separated high-voltage and low-voltage components may reduce the cost and increase the manufacturability' of the electronic assembly by leveraging the existing manufacturing structure of low-voltage technology (such as CMOS transistors).

[0036] To ensure sufficient image quality, transmission and receipt of ultrasonic signals, in general, often involves managing the angle and frequency of the transmitted signal. This management is necessary to avoid distortions that can reduce resulting image quality. Managing the angle and frequency of the transmitted signal can be accomplished in different ways. For example, different elements of a transducer array may be excited at different times, creating a beam in a direction (referred to herein as "‘transmission beamforming’7). As another example, a transducer array may be rotated to set phases and the received signals may be reconstructed into images used in diagnosis and treatment of the vessel. This technique requires that the frequency of the rotation remain relatively uniform. Another technique involves use of several transducers on a solid-state array in transmission beamforming to electronically adjust the angle of the beam by varying the timing between emitted signals of each transducer. This technique requires precise control over the timing of transmitted signals to control the angle and frequency of the transmitted signal.

[0037] FIG. 1A illustrates a representation of an example system 100 for performing IVUS. The system 100 can include a catheter 108 coupled to a control device (or controller) 102 on the proximal end of the catheter 108. The catheter 108 includes a catheter tip 106 (also referred to as a “probe”) on the distal end 107 of the catheter 108. The illustrated system 100 can also include a processing system 105 that includes a display (e.g., a monitor 104) that is coupled to the control device 102 be in communication with the control device 102. In this embodiment, a physical connector 1 10 can couple the processing system 105 to the control device 102, where a distal end of the connector 110 is coupled to the control device 102 and a proximal end of the connector 110 is coupled to the processing system 105. The connector 110 can include one or more communication channels (e.g., wires, fiber). The control device 102 may communicate signals received from the catheter tip 106 to the processing system 105 using the connector 110. In some embodiments, the distal end of the connector 110 is releasably connected to the control device 102. In some embodiments, the proximal end of connector 110 is releasably connected to the processing system 105. In an alternate embodiment, the control device 102 is wirelessly coupled to the processing system 105 such that the control device communicates wirelessly with the processing system 105.

[0038] The control device 102 can include components configured to control the catheter 108 and its components, including one or more components located at the catheter tip 106. The catheter tip 106 and components on or in the catheter tip 106 can becollectively referred to herein as the catheter tip 106 for ease of reference. In some embodiments the control device 102 can include one or more motors, electrical connections, steering assemblies, controls, power delivery circuitry, an interface, signal transmit and receipt circuitry', and / or components that allow the control device 102 to steer and / or rotate the catheter 108, communicate signals to the catheter tip, receive signals from the catheter tip 106 and the like. In some embodiments, the control device 102 may include a user interface. For example, the control device 102 can include buttons, dials, touch interfaces, or a display, and the like, that allow a user to control the operation of the catheter (for example, steering, imaging, ablation, and the like). In some embodiments the control device 102 is a catheter handle. In some embodiments, the control device 102 is a durable catheter handle, for example, as described in U.S. Patent Application No. 17 / 820.139. filed August 16, 2022, or as described in PCT / US23 / 73371, filed September 1, 2023, each of these disclosures being incorporated herein in its entirety.

[0039] The processing system 105 can be configured with components for processing and / or displaying signals from the catheter tip 106 via the control device 102. For example, the processing system 105 can include one or more processors, memory configured with computer instructions that are executable by the one or more processors, communication circuits, and / or one or more displays for displaying information and / or images related to the system, the patient, and / or the procedure being performed. The processing system 105 may be configured to generate and display images and / or information based on the received signals. In some embodiments, the processing system 105may store received signals over time and generate a representation of a sensed object. For example, the processing system 105 may utilize signals over time to generate a representation of all or a portion of a vascular vessel. In some embodiments, the processing system 105 can be a processing system disclosed in PCT / US2023 / 073675 filed September 1, 2023 (e.g., a multiple-modality system), or a processing system disclosed in PCT / US2023 / 073684 filed September 7, 2023, each of these disclosures being incorporated herein in its entirety.

[0040] The catheter 108 may be an elongate flexible member adapted to be inserted into a patient’s vasculature. For certain medical procedures, the catheter 108 is inserted into a patient and distal end 107 is positioned in the vasculature of the patient, such as a vascular vessel. Various medical catheters and cannulas may be used for the catheter 108. The control device 102 can control movement of the catheter and may control functionality of the catheter as well. In an example, during a medical procedure the controldevice 102 can steer the distal end 107 of the catheter 108 and rotate the catheter 108. The catheter 108 includes a communication cable (“cable”), extending from the catheter tip 106 through the catheter 108, and it can be coupled to the control device 102. The cable can include power delivery and data delivery connections to connect the catheter tip 106 (and components positioned in the distal portion of the catheter) to the control device 102. The cable can include multiple channels. For example, in some instances the cable may include channels to communicate analog signals (e.g., radio frequency signals). In some embodiments, the cable can include 128 channels for communicating analog signals. In other instances, the cable may include 196 channels for analog signals. However, the number of analog channels on the cable may be few than 128 or 196 channels or larger than 128 or 196 channels. In one non-limiting example, the cable includes up to 196 analog channels, up to 8 digital channels (e.g., for low voltage differential signals (LVDS)), at least one channel for a control bus, and at least one channel for power delivery. In some embodiments, the cable may include ultra-miniature coaxial cables (referred to herein as a “uCoax bundle ”).

[0041] The catheter tip 106 may have a curved surface on the distal end of the catheter 108. The catheter tip 106 can include the sensors and circuitry to perform IVUS. For example, the catheter tip 106 can include one or more ultrasound electronic assemblies that can generate and receive the ultrasound signals for performing IVUS. In some embodiments, the catheter tip 106 may include non-imaging functionality such as components to perform ablation. The catheter tip 106 will be described in more detail below.

[0042] In a typical IVUS procedure, the catheter tip 106 and the catheter 108 may be inserted into a vasculature of the patient. The catheter tip 106 can generate ultrasound information that is used to produce an image of the patient’s vasculature, from within the vasculature, and transmit the information or signals (which can be referred to herein as “sensor signals”) to the controller device 102 via the cable of the catheter 108, and / or to the processing system 105. As such, two size constraints to note are the size of the cable within the catheter 108 and the size of the catheter tip 106. If either become too large, patient comfort may decrease or, in some circumstances, the system 100 may no longer be suitable for IVUS applications.

[0043] FIG. IB is a block diagram 150 illustrating signal communication between the catheter tip 106, the controller device 102. and the processing system 105 during ultrasound imaging. According to various embodiments, the controller device 102can transmit a control signal 152 to the catheter tip 106. The control signal 152 may be transmitted via the cable of the catheter 108. The control signal 152 can include beamforming information, such as frequency information, timing information, directional information, or other information used in beamforming. The control signal 152 can also include other information, such as control information to one or more components located in the catheter tip 106. For example, one or more motors and / or one or more assemblies comprising a transducer. As is described in more detail in FIGS. 4A and 4B, the catheter tip 106 can process the control signal 152 to generate an ultrasound signal, receive echoes of the ultrasound signal, and generate a sensor signal 154 based on the received echoes. The sensor signal 154 can include analog signals of the received echoes. In some embodiments, the sensor signal 154 can also include, or be entirely made of, digitized signals based on analog signals of the received echoes.

[0044] The controller device 102 may process the sensor signal 154 to generate a display signal 156. The display signal 156 can be analog and / or digital information the monitoring device 104 uses to display ultrasound images associated with the received echoes (e.g., ultrasound images of a portion of the patient’s heart). In various embodiments, the signal processing by the control device 102 to convert the sensor signal 154 into the display signal 156 can include, but is not limited to, beamforming (such as dynamic, synthetic, or other beamforming), time gain compensation, digital and / or analog filtering, Doppler processing (such as color Doppler or Spectral Doppler), speckle reduction. B- mode image processing, three dimensional (3D) or four dimensional (4D) image processing (such as 4D image construction), harmonic image processing, of other image processing techniques used in ultrasound imaging.

[0045] The processing system 105 can receive the display signal 156 and display an ultrasound image (e.g., via the monitoring device 104). In various embodiments, the functionalities described with reference to the control device 102 or processing system 105 may be performed elsewhere. For example, signal processing of the sensor signal 154 may take place on the processing system 105. In this example, the controller device 102 may pass the sensor signal 154 on to the monitoring device 104 without any processing. In some instances, the control device 102 and the processing system 105 may form a single unit that both controls the catheter tip 106 and displays ultrasound images.

[0046] FIG. 2A is a cross section of a catheter tip, such as catheter tip 106, illustrating an example configuration 200 of an ultrasonic transducer assemblies within the catheter tip. Configuration 200 is shown such that axis XX’ is aligned along a center of thecatheter tip. The axis XX’ may be defined as intersecting the center of a curved surface on the distal end of the catheter tip. As illustrated, the catheter tip includes an inner housing 202a, an outer housing 202b, ultrasound transducer arrays 206, and ultrasound electronics assemblies 204. While eight ultrasound transducer arrays 206 and ultrasound electronics assemblies 204 are depicted in FIG. 2A, the catheter tip may include more (e.g., eight or nine) or fewer (e.g., four or five) ultrasound transducer arrays 206 and ultrasound electronics assemblies 204 arranged on the radial outward portion of the catheter tip. Furthermore, while FIG. 2A shows that the ultrasound transducer arrays 206 fully surround the catheter tip, the present disclosure is not limited to such configurations. For example, 400, the ultrasound transducer arrays 206 may partially surround the catheter tip. Various embodiments provide certain benefits, as the catheter may not need to be rotated to radially emit ultrasound signals, as the multiple ultrasound transducer arrays 206 are radially arranged to radially emit ultrasound signals without the need of rotating the ultrasound transducer arrays 206.

[0047] Each ultrasound transducer array 206 may include a plurality of ultrasonic transducer elements. Each ultrasonic transducer element may receive an electric signal (e g., a high-voltage signal) and convert the electric signal into an ultrasound signal, which are emitted from the transducer arrays 206. Each ultrasonic transducer elements of the ultrasound transducer array can interact with the ultrasound signals of each other to form directional beams of ultrasound signals. The use of high (or first) voltage (“HV”) pulses can allow the directional beams to be controlled through a beamforming signal. The circuitry used to generate the high voltage pulses (referred to herein as HV circuitry ” and described below in FIG. 2B) in an ultrasound electronics assembly may operate at a first voltage higher than a second voltage to be used for LV circuitry in the ultrasound electronics assembly (described below in FIG. 2B). HV pulses can be up to or about 30 volts (60 VPP) or, in some cases higher. These voltages are merely examples, other voltages can be used for HV pulses. The ultrasound transducer arrays 206 will be described in more detail with reference to FIG. 6.

[0048] The ultrasound electronics assemblies 204 can include the structural and electronic circuitry configured to deliver signals to, and receive signals from, the ultrasound transducer arrays 206. The ultrasound electronics assemblies 204 will be described in more detail with reference to FIGS. 2B, 3A, 3B, 4A, 4B, 5A. and 5B. In various embodiments, the configuration 200 can include other components including, but not limited to. one or more sensors (e.g. a pressure sensor), ablation components, or other imaging components.

[0049] In some embodiments, the diameter of the outer housing (Wl) is about 1000 microns and the diameter of the inner housing (W2) is about 750 microns. These diameters are merely examples, and the present disclosure is not limited thereto. For example, other diameters smaller than about 3500 microns or greater than 4500 microns can also be used.

[0050] FIG. 2B is a perspective view of an example embodiment 250 of an ultrasound electronics assembly, for example, ultrasound electronics assembly 204. The embodiment 250 includes an ultrasound transducer array 206, a high-voltage chipl et 210, a low-voltage chiplet 212, a substrate 214, connection paths 216a-216c, and a connection interface 218 for connecting cable 220 to other components of the ultrasound electronics assembly 250.

[0051] FIG. 2B shows merely an example embodiment where relative dimensions of the elements 206-220 are for illustrative purpose only. For example, widths of one or more of the ultrasound transducer array 206, the high-voltage chiplet 210, or the low-voltage chiplet 212 may be smaller or substantially the same as that of the substrate 214. As another example, a width and / or a length of the ultrasound transducer array 206 may be smaller or substantially the same as the respective one of the high-voltage chiplet 210. While FIG. 2B shows a single high-voltage chiplet 210, two or more high-voltage chiplets can be disposed between the substrate 214 and the ultrasound transducer array 206 in some embodiments. In these embodiments, thicknesses of each of these two or more high-voltage chiplets may be smaller than that of the single high-voltage chiplet 210 shown in FIG. 2B not to exceed a predetermined height required for the ultrasound electronics assembly. The description of this paragraph may apply to one or more of the other embodiments shown in FIGS. 5A and 5B. In various embodiments, the total thickness of the ultrasound electronics assembly 250 (e.g., the total height of the substrate 214, high- voltage chiplet 210 and transducer array 206 together) may be approximately 300 microns. However, the ultrasound electronics assembly 250 may have a thickness of greater or less than 300 microns.

[0052] As previously described, the ultrasound transducer array 206 may receive high-voltage signals (also referred to as “HV pulses” or ‘'high-voltage pulses”) to form directional beams of ultrasound signals. The high-voltage signals may be generated by the high-voltage chiplet 210 in response to low-voltage transmission signal. The low- voltage transmission signal may include beamforming signals. Portions of the beamforming signals may be generated by beamformer logic on the high-voltage chiplet210 and / or the low-voltage chiplet 212. In some embodiments, the ultrasound transducer array 206 may be a one dimensional (‘"ID”) ultrasonic transducer element array of 8 elements. In some embodiments, the ultrasound transducer array 206 may operate at a frequency (fo> of about 28 MHz.

[0053] The high-voltage chiplet 210 may be and / or include one or more application specific integrated circuits (ASIC), one or more integrated circuit, and / or other electronic circuitry. The high-voltage chiplet 210 may include HV circuitry for processing high-voltage signals, for example, signals reaching or exceeding 200 VPP. The HV circuitry can include BCD technology, program registers, transmit and receipt (“T / R”) switches, transmit beamforming logic, serial peripheral interfaces (“SPI”), and / or the like to facilitate the transmission and reception of ultrasound signals through the ultrasound transducer array 206. In some embodiments, the high-voltage chiplet 210 may include 8 output interfaces, 8 T / R switches, and transmit beamforming circuitry. In some embodiments, the high-voltage chiplet 210 can include one or more BCDs. The high-voltage chiplet 210 may operate at and / or generate high voltage pulses in the range of 10-60 VPP. In some embodiments, the high-voltage chiplet can generate up to a 200 VPP pulse. In various embodiments, all the processing of high-voltage signals is performed on the high-voltage chiplet 210. As such, signals to and from the high-voltage chiplet from the low-voltage chiplet may all be low-voltage signals (e.g., low -voltage transmission signals and low- voltage reception signals).

[0054] The low-voltage chiplet 212 may be and / or include one or more ASICS, one or more integrated circuits, and / or other electronic circuitry. The low-voltage chiplet 212 may include circuitry7for processing low-voltage signals, for example, signals of less than 10 V, 1 V. 1 mV, or less than 10 pV. The circuitry7can include low (or second) voltage (“LV”) circuitry (e.g., low7voltage CMOS transistors), attenuators, low noise amplifiers (“LNA”), high-pass filters, low-pass filters, program registers, analog-to-digital converters, phase loc loops (“PLL’'), thermal controls, SPIs, serial / deserializer circuits (“serdes”), and / or the like that operate at low voltages. The low-voltage chiplet 212 may facilitate the generation of pulses in the high-voltage chiplet 210 using low-voltage transmission signals and process low7-voltage reception signals from the high-voltage chiplet 210. The LV circuitry7may operate at a second voltage (e.g., 10 V, 1 V, 1 mV, or less than 10 pV) less than the first voltage (e.g., up to 60 Vpp or more) of the HV circuitry7described above. The low-voltage chiplet 212 may send and receive signals to the high-voltage chiplet 210 using connection path 216b. In some embodiments, the low-voltage chiplet 212 may include 8-to-1 analog beamformer circuitry. In some embodiments, the low-voltage chiplet 212 may include analog-to-digital circuits (e.g.. eight analog-to-digital converters) with digital beamformer and low voltage digital signal lines out. The low-voltage chiplet 212 may send and receive 8 analog signals (e.g., radio frequency signals) and 4-8 digital signals to and / or from the high-voltage chiplet 210. For example, in some embodiments, the low-voltage chiplet 212 sends digital signals to the high-voltage chiplet 210 and receives analog signals from the high-voltage chiplet 210. The numbers of the above signals are merely examples, and the present disclosure is not limited thereto. For example, other numbers of the signals can also be used.

[0055] The low-voltage chiplet 212 may send and receive signals to and from the connection interface using connection path 216c. In some embodiments, the low- voltage chiplet 212 may send and receive one low voltage differential signal C'LVDS”) pair, one control bus and power delivery signals to and from the connection interface connection interface 218. The low-voltage chiplet 212 can include CMOS circuits. In some embodiments, the low-voltage chiplet 212 operates exclusively at low voltages. This may allow the low-voltage chiplet 212 the expanded use of available circuitry in the low-voltage chiplet 212 as no specification for high-voltage operation is needed. As such, the low- voltage chiplet 212 may allow for reduced production costs and critical space requirements. Further, the separation of the high-voltage chiplet 210 and the low-voltage chiplet 212 by a substrate 214 may allow for increased thermal dissipation and reduced noise from the high-voltage chiplet received by the low-voltage chiplet 212 components.

[0056] The substrate 214 may be a flip chip ball grid array (“FCBGA”) or another suitable substate suited for connecting multiple integrated components. The substrate 214 may accommodate and / or provide a signal path for the low- voltage chiplet 212, high-voltage chiplet 210, and / or the ultrasound transducer array 206. The substrate 214 can include connection pathways 216a-216c to facilitate communication through the substrate 214. The connection pathway 216b may facilitate the connection between the high-voltage chiplet 210 and the low-voltage chiplet 212. The connection pathway 216a may facilitate the connection between the high-voltage chiplet 210 and the ultrasound transducer array 206. In some embodiments, the substrate 214 can include high density routing die for connection pathways 216a-216c. The high density routing die may be part of the substrate 214 and / or may be embedded in the substrate 214. The high density routing die may include a high density of connections such as analog signal connections, digital signal connections, control buses, power delivery, and / or the like. In various embodiments,the substrate may include multiple layer, each capable of transmitting a high density of signals. For example, the high density routing die 216, may include four layers, each layer capable of transmitting a high number (e.g., approximately 1250) of signals. In some embodiments, at least a portion of the substrate 214 comprises or is made of organic material. The high density routing die will be described in more detail with reference to FIG. 7.

[0057] In some embodiments, the substrate 214 can include one or more ball grid arrays (BGA). The BGA can include an array of solder balls (also referred to as bumps) to facilitate the electrical and physical coupling of the substrate 214 to the ultrasound transducer array 206, high-voltage chiplet 210 and low-voltage chiplet 212. However, other packaging and connecting conventions may be used to facilitate the connection of the substrate 214 to the ultrasound transducer array 206, high-voltage chiplet 210 and low- voltage chiplet 212.

[0058] The substrate 214 can also facilitate the connection between the low- voltage chiplet 212 and the connection interface 218 using connection pathway 216c. The connection pathway 216c may include connections such as RF signal connections, digital signal connections, control buses, and power delivery. In some embodiments, the connection pathway 216c includes a low voltage digital signal pair, a control bus, and a power delivery connection between the low-voltage chiplet 212 and the connection interface 218. The numbers of the above signal connections are merely examples, and the present disclosure is not limited thereto. For example, other numbers of the signal connections can also be used.

[0059] The connection interface 218 can include connections for external connections to the cable 220 to send and receive signals and receive power delivery’. For example, the connection interface 218 can include a plurality of leads that can be connected to the cable 220. The cable 220 may be a uCoax bundle. In some embodiments, the cable 220 can send and receive 10 low voltage digital signals. In some embodiments, the connection interface 218 can include a programable gate array (PGA), a field programable gate array (FGA) and / or other programable circuitry to configure and / or reconfigure I / O connections on the connection interface 218. the cable 220 may be physically and electrically connected to the 218, for example, using solder connections.

[0060] The ultrasound transducer array 206, the high-voltage chiplet 210, and the low-voltage chiplet 212 may be bonded to the substrate 214. for example, using die-to- die bonding. In some embodiments, the die-to-die boding has a bump pitch of about 36microns or less. In some embodiments, the die-to-die boding has a bump pitch of about 25 microns or less. In some embodiments, the die-to-die boding has a bump pitch of about 10 microns or less.

[0061] FIG. 3 A illustrates an example signal path 300 of a received signal (e.g., a control signal) to the generation of an ultrasound signal through an ultrasound electronics assembly (e.g., ultrasound electronics assembly 250 of FIG. 2B). In the illustrated example, the signal path 300 includes a control signal 302, a low-voltage transmission signal 304. a high-voltage signal 306, and an ultrasound signal 308.

[0062] The control signal 302 can be a signal received from a controller device, such as control signal 152 of FIG. IB, via the connection pathway 216c. The control signal 302 can include information associated with controlling the transducer array 206 to transmit ultrasound signals in a defined way. For example, the control signal can include beamforming information, such as frequency information, timing information, directional information, or other information used in beamforming. The control signal 302 can also include information associated with the reception of ultrasound signals, such as settings and / or configurations for circuitry on the low-voltage chipl et 212 and / or high-voltage chiplet 210 used in ultrasound signal processing (e.g., receive beamforming settings, filter settings, amplifier settings, T / R switch settings, timing information, and / or other information used in the reception of ultrasound signals). In some embodiments, the control signal 302 can include digital signals and / or low voltage differential signaling (LVDS). The control signal can include power delivery to the ultrasound electronics assembly 250.The control signal 302 may be configured to instruct the low-voltage chiplet 212 and / or the high-voltage chiplet 210. For example, in some embodiments, the control signal 302 includes instructions for the low-voltage chiplet 212 to generate a particular low-voltage transmission signal 304. In some embodiments, the control signal 302 includes the low- voltage transmission signal 304. In these embodiments, the low-voltage chiplet 212 may pass through the low-voltage transmission signal 304 from the received control signal 302.

[0063] The low-voltage transmission signal 304 can include all or a portion of the information associated with controlling the high-voltage chiplet 210 and / or transducer array 206 described above with respect to the control signal 302. In some embodiments, the low-voltage transmission signal 304 may include additional information provided by the low-voltage chiplet 212. For example, the low-voltage chiplet 212 may include information specific to configuring the high-voltage chiplet 210 to transmit an ultrasound signal. In other embodiments, all of the low-voltage transmission signal 304 may be partof the control signal 302 and passed through the low-voltage chiplet 212. The low-voltage transmission signal 304 can also include information associated with the reception of ultrasound signals, such as settings and / or configurations for circuitry on the high-voltage chiplet 210 used in ultrasound signal processing (e.g., T / R switch settings, timing information, and / or other information used in the reception of ultrasound signals). In some embodiments, the low-voltage transmission signal 304 includes digital signals and / or LVDS configured to instruct the high-voltage chiplet 210. The low-voltage transmission signal 304 may be provided to the connection pathway 216a by the low-voltage chiplet 212. The low-voltage transmission signal 304 may be provided by the connection pathway 216b to the high-voltage chiplet 210.

[0064] The high-voltage chiplet 210 can receive the low-voltage transmission signal 304 and generate the high-voltage signal 306. The high-voltage signal 306 can be a high-voltage pulse configured to cause the ultrasound transducer array 206 to form an ultrasound signal 308. The ultrasound signal 308 may be an ultrasound beam (U / S beam). As such, the high-voltage signal 306 can include variable timing and / or amplitudes for each transducers element of the 206 to form the U / S beam in a desired direction. The high- voltage signal 306 can also include a frequency and duration. For example, the high-voltage signal 306 can cause ultrasound transducer array 206 to generate an U / S beam with a defined band of frequency, a defined duration (also referred to as the ‘‘pulse width’"), and a defined center frequency. The high-voltage chiplet 210 can include a pulse generator and a beamformer that generates the high-voltage signal 306 based on the low-voltage transmission signal 304. The high-voltage signal 306 can have a relatively high voltage compared to the low-voltage transmission signal 304. For example, the high-voltage signal 306 can be up to 60 VPP, or in some cases even a higher- voltage (e.g.. in some applications the high-voltage signal 306 may reach or exceed 200 VPP. In contrast, LVDS in the low- voltage transmission signal 304 can have differential voltages of approximately 350 milliVolts peak-to-peak (mVpp) and common-mode voltages of approximately 1.2 V. The high- voltage signal 306 may be provided to the connection pathway 216a by the high-voltage chiplet 210. The high-voltage signal 306 may be provided by the connection pathway 216a to the ultrasound transducer array 206.

[0065] The ultrasound transducer array 206 may receive the high-voltage signal 306 and generate the ultrasound signal 308. For example, the high-voltage signal 306 may cause individual transducer elements to emit ultrasound waves with a frequency bandwidth, pulse width, and center frequency. Each individual transducer may emit the ultrasoundwave with differing timings and amplitudes, collectively forming the ultrasound signal 310 (e.g., the U / S beam). The ultrasound signal 308 propagates into a patient (e.g., into the patient’s vasculature in IVUS applications), where the ultrasound waves of the signal 308 reflect at differing depths and return to the transducer array 206.

[0066] FIG. 3B illustrates an example signal path 350 of a received ultrasound signal (e.g., reflected ultrasound waves from ultrasound signal 308 of FIG. 3A) to the generation of a sensor signal through an ultrasound electronics assembly (e.g.. ultrasound electronics assembly 250 of FIG. 2B). In the illustrated example, the signal path 350 includes an ultrasound signal 352, a low-voltage reception signal 354, a low-voltage reception signal 356, and a sensor signal 358. The number of channels of signals is reduced from the low-voltage reception signal 354, which can have a channel for every element of the ultrasound transducer array 206, to the sensor signal 360 which includes reduced signals (e.g., beamformed signals). As such, the cable used to transmit the sensor signal 360 may have a reduced size, increasing the suitability7for catheter applications.

[0067] The ultrasound signal 352 can include ultrasound waves of various frequencies and amplitudes. The ultrasound waves may be reflected ultrasound waves from the generated ultrasound signal 308 of FIG. 3A. The ultrasound signal 352 can include ultrasound waves at different instances in time. The ultrasound transducer array 206 can generate the low-voltage reception signal 354 based on the ultrasound signal 352. As the ultrasound waves of the ultrasound signal 352 reach the ultrasound transducer array 206, individual transducer elements of the ultrasound transducer array 206 can generate analog signals based on the ultrasound waves. The analog signals can include information associated with the ultrasound signal 352, such as frequencies, amplitudes, durations, and / or other attributes of the ultrasound signal 352. The low-voltage reception signal 354 can include and / or be made entirely of these analog signals. The number of analog signals can correspond to the number of transducer elements of the ultrasound transducer array 206. For example, an 8x1 ultrasound transducer array 206 can generate eight analog signals, which make up the low-voltage reception signal 354.

[0068] According to various embodiments, the low-voltage reception signal 354 can have a significantly attenuated voltage compared to the high-voltage signal 308 of FIG. 3A. In some instances, the low-voltage reception signal 354 may have a voltage in the order of magnitude millivolts (mV) or microvolts (pV). For example, some of the ultrasound waves of the ultrasound signal 352 may have reflected from a more distant target or from a target with a low reflectivity. In this example, the analog signals generated fromthese ultrasound waves may have a voltage of less than 10 pV. As such, multiple orders of magnitude may separate the voltages of the high-voltage signal 308 and the low-voltage reception signal 354.

[0069] The low-voltage reception signal 354 can be transmitted to the high- voltage chiplet 210 from the ultrasound transducer array 206. For example, the low-voltage reception signal 354 can be provided to the connection pathway 216a (e.g., using electrical connections between the ultrasound transducer array 206 and the substrate 214) and the connection pathway 216a can provide the low-voltage reception signal 354 to the high- voltage chiplet 210 (e.g., using electrical connections between the high-voltage chiplet 210 and the substrate 214). In some embodiments, the high-voltage chiplet 210 may not process or may minimally process the low-voltage reception signal 354. The high-voltage chiplet 210 may be configured to pass the low-voltage reception signal 354 directly from to the ultrasound transducer array 206 to the connection pathway 216b. As such, the low-voltage reception signal 356 and the low-voltage reception signal 354 can contain the same information. In some embodiments, the low-voltage reception signal 354 and low-voltage reception signal 356 are a continuous signal. Accordingly, the high-voltage chiplet 210 may have a number of channels for passing the low-voltage reception signal 354 that is equal to the number of transducer elements of the ultrasound transducer array 206 (e.g., eight).

[0070] The low-voltage reception signal 356 can be transmitted to the low- voltage chiplet 212 from the high-voltage chiplet 210. For example, the low-voltage reception signal 356 can be provided to the connection pathway 216b (e.g., using electrical connections between the high-voltage chiplet 210 and the substrate 214) and the connection pathw ay 216a can provide the low-voltage reception signal 356 to the low-voltage chiplet 212 (e.g., using electrical connections between the low-voltage chiplet 212 and the substrate 214). The low-voltage chiplet 212 can process the analog signals of the low- voltage reception signal 356 and reduce the number of signals. For example, the low- voltage chiplet 212 may include analog beamformers that can perform sub-array beamforming (also referred to as ’sub-aperture beamforming,’' or "front-end beamforming”) that combines multiple analog signals into a single analog signal. In one embodiment, the low-voltage chiplet 212 includes analog beamformers that can combine eight analog signals into one analog signal. The low-voltage chiplet 212 can include analog- to-digital converters (ADC) that convert the analog signals into digital signals. In one embodiment, the low-voltage chiplet 212 includes an ADC for every element of the ultrasound transducer array 206. The low- voltage chiplet 212 can include digitalbeamformers that can reduce the total number of digital signals received from the ADCs. For example, the low-voltage chiplet 212 can include eight ADCs and digital beamformers that reduce the eight digital signals at the output of the ADCs to a digital signals. The low- voltage chiplet 212 may process the analog signals in other ways. For example, attenuators on the low-voltage chiplet 212 can reduce high amplitude signals (e.g., signals above a threshold voltage, such as 1.2 V), low noise amplifiers on the low-voltage chiplet 212 can amplify signals below a threshold, and filters can filter out frequencies above and / or below a desired. However, the low-voltage chiplet 212 is not limited by these examples and can otherwise process the analog signals.

[0071] According to various embodiments, the low-voltage chiplet 212 may only include components used for processing low-voltage signals. This may allow the low- voltage chiplet 212 to leverage state-of-the art technology not available when integrating high-power components onto the same chiplet. For example, the low-voltage chiplet 212 may leverage sophisticated sub-array beamforming that can be used with higher levels of programmability, higher component density that accompany smaller transistors, and better power efficiency.

[0072] The sensor signal 358 can be a result of the processing performed by the low-voltage chiplet 212. In some embodiments, the sensor signal 358 can include filtered and beamformed analog signals. In some embodiments, the sensor signal 358 can include digital signals from ADCs and / or digital beamformers of the low-voltage chiplet 212. The sensor signal 358 can be transmitted to the connection pathway 216c (e g., through electrical connections between the low-voltage chiplet 212 and the substrate 214). The connection pathway 216c may provide electrical connection to the connection interface 218 and / or cable 220. such that the sensor signal 358 can be communicated from the ultrasound electronics assembly 250 to a control device, such as control device 102 of FIGS. 1A and IB, where the sensor signal 360 can be converted into a display signal.

[0073] FIG. 4A illustrates a flow diagram of a process 400 for generating an ultrasound signal based on a control signal. The steps of process 400 described in association with FIG. 4A can be performed in a different sequence, can be added, merged, or left out altogether (e g., not all described acts or events are necessary for the process). Moreover, in certain embodiments, functions, acts or events can be performed concurrently. The steps of process 400 may be performed by an ultrasound electronics assembly, such as ultrasound electronics assembly 250 of FIG. 2B.

[0074] At block 402, the ultrasound electronics assembly receives, at a low- voltage chiplet (e.g., the low-voltage chiplet 212 of FIG. 2B), a control signal from a controller device (e.g., the control device 102 of FIGS. 1 A and IB). The control signal can include information associated with controlling a transducer array to transmit ultrasound signals in a defined way. For example, the control signal can include beamforming information, such as frequency information, timing information, directional information, or other information used in beamforming. The control signal can also include information associated with the reception of ultrasound signals, such as settings and / or configurations for ci rcni try on the low-voltage chiplet and / or high-voltage chiplet used in ultrasound signal processing (e.g., receive beamforming settings, filter settings, amplifier settings, T / R switch settings, timing information, and / or other information used in the reception of ultrasound signals). In some embodiments, the control signal can include digital signals and / or low voltage differential signaling (LVDS). The control signal can include power delivery' to the ultrasound electronics assembly. The control signal may be configured to instruct the low-voltage chiplet and / or the high-voltage chiplet. For example, in some embodiments, the control signal includes instructions for the low-voltage chiplet to generate a particular low-voltage transmission signal. In some embodiments, the control signal includes the low-voltage transmission signal.

[0075] At block 404, the low-voltage chiplet generates a low-voltage transmission signal. The low-voltage transmission signal can include all or a portion of the information associated with controlling the high-voltage chiplet and / or transducer array described above with respect to the control signal. In some embodiments, the low-voltage transmission signal may include additional information provided by the low-voltage chiplet. For example, the low-voltage chiplet may include information specific to configuring the high-voltage chiplet to transmit an ultrasound signal. In other embodiments, all of the low-voltage transmission signal may be part of the control signal and passed through the low-voltage chiplet at block 402. The low-voltage transmission signal can also include information associated with the reception of ultrasound signals, such as settings and / or configurations for circuitry on the high-voltage chiplet used in ultrasound signal processing (e.g., T / R switch settings, timing information, and / or other information used in the reception of ultrasound signals). In some embodiments, the low-voltage transmission signal includes digital signals and / or LVDS configured to instruct the high- voltage chiplet.

[0076] At block 406, ultrasound electronics assembly transmits the low-voltage transmission signal to the high-voltage chiplet via the substrate. The substrate can include electrical connection from the low-voltage chiplet to the high-voltage chiplet (e.g., connection pathway 216b of FIG. 2B). In some embodiments, the substrate may include a high density routing die, such as the high density routing die 706 of FIG. 7 that forms the connection pathway 216b.

[0077] At block 408. the high-voltage chiplet generates a high-voltage signal (e.g., a high-voltage pulse) from the low-voltage transmission signal. The high-voltage signal can be a high-voltage pulse configured to cause an ultrasound transducer array to form an ultrasound signal. The ultrasound signal may be an ultrasound beam (U / S beam). As such, the high-voltage signal can include variable timing and / or amplitudes for each transducers element of the to form the U / S beam in a desired direction. The high-voltage signal can also include a frequency and duration. For example, the high-voltage signal can cause ultrasound transducer array to generate and U / S beam with a defined band of frequency, a defined duration (also referred to as the “pulse width"’), and a defined center frequency. The high-voltage chiplet can include a pulse generator and a beamformer that generates the high-voltage signal based on the low-voltage transmission signal. The high- voltage signal can have a relatively high voltage compared to the low-voltage transmission signal. For example, the high-voltage signal can be up to 60 VPP. or in some cases even a higher-voltage (e.g., in some applications the high-voltage signal may reach or exceed 200 VPP. In contrast, LVDS in the low-voltage transmission signal can have differential voltages of approximately 350 milli-Volts peak-to-peak (mVpp) and common-mode voltages of approximately 1.2 V.

[0078] At block 410. the high-voltage chiplet transmits the high-voltage signal to the transducer array via the substrate. The substrate can include electrical connection from the high-voltage chiplet to the transducer array (e.g., connection pathway 216a of FIG. 2B). In some embodiments, the substrate may include a high density routing die, such as the high density routing die 706 of FIG. 7 that forms the connection pathway 216a. In some embodiments, the high-voltage chiplet may be separated from the transducer array a flexible printed circuit card (“FPC”) and the high-voltage signal may be provided to the transducer array via the FPC. The FPC includes electrical connections from the high- voltage chiplet to the transducer array that can transmit the high-voltage signal.

[0079] At block 412, the ultrasound transducer array may receive the high- voltage signal and generate an ultrasound signal. For example, the high-voltage signal maycause individual transducer elements to emit ultrasound waves with a frequency bandwidth, pulse width, and center frequency. Each individual transducer may emit the ultrasound wave with differing timings and amplitudes, collectively forming the ultrasound signal (e.g., an U / S beam). The ultrasound signal propagates into a patient (e.g., into the patient’s heart in ICE applications), where the ultrasound waves of the signal reflect at differing depths and return to the transducer array.

[0080] FIG. 4B illustrates a flow diagram of a process 450 for generating a sensor signal. The steps of process 450 described in association with FIG. 4B can be performed in a different sequence, can be added, merged, or left out altogether (e.g., not all described acts or events are necessary for the process). Moreover, in certain embodiments, functions, acts or events can be performed concurrently. The steps of process 450 may be performed by an ultrasound electronics assembly, such as ultrasound electronics assembly 250 of FIG. 2B.

[0081] At block 452, an ultrasound transducer array generates a low-voltage reception signal based on ultrasound waves. The ultrasound waves can have various frequencies and amplitudes. The ultrasound waves may be reflected ultrasound waves from the ultrasound signal generated at block 412 of FIG. 4A. The ultrasound waves can include ultrasound waves at different instances in time. As the ultrasound waves reach the ultrasound transducer array 206, individual transducer elements of the ultrasound transducer array can generate analog signals based on the ultrasound waves. The analog signals can include information associated with the ultrasound waves, such as frequencies, amplitudes, durations, and / or other attributes of the ultrasound waves. The low-voltage reception signal can include and / or be made entirely of these analog signals. The number of analog signals can correspond to the number of transducer elements of the ultrasound transducer array. For example, an 8x1 ultrasound transducer array can generate 8 analog signals, which make up the low-voltage reception signal.

[0082] According to various embodiments, the low-voltage reception signal can have a significantly attenuated voltage compared to the high-voltage signal of process 400 of FIG. 3 A. In some instances, the low-voltage reception signal may have a voltage in the order of magnitude millivolts (mV) or microvolts (pV). For example, some of the ultrasound waves may have reflected from a more distant target or from a target with a low reflectivity. In this example, the analog signals generated from these ultrasound waves may have a voltage of less than 10 pV. As such, multiple orders of magnitude may separate the voltages of the high-voltage signal and the low-voltage reception signal.

[0083] At block 454, the ultrasound transducer array transmits the low-voltage reception signal to the high-voltage chiplet via the substrate. The substrate can include electrical connection from the high-voltage chiplet to the transducer array (e.g., connection pathway 216a of FIG. 2B). In some embodiments, the substrate may include a high density routing die, such as the high density routing die 706 of FIG. 7 that forms the connection pathway 216a. In some embodiments, the high-voltage chiplet may be separated from the transducer array an FPC and the low-voltage reception signal may be provided to the transducer array via the FPC. The FPC includes electrical connections from the high- voltage chiplet to the transducer array that can transmit the low-voltage reception signal.

[0084] At block 456, the high-voltage chiplet transmits the low-voltage reception signal to the low-voltage chiplet via the substrate. The substrate can include electrical connection from the high-voltage chiplet to the low-voltage chiplet (e.g., connection pathway 216b of FIG. 2B). In some embodiments, the high-voltage chiplet may not process or may minimally process the low-voltage reception signal. The high-voltage chiplet may be configured to pass the low-voltage reception signal received from a connection path of the substrate (e.g., connection path 216a) directly to another connection path of the substrate (e g., connection path 216b). Accordingly, the high-voltage chiplet may have a number of channels for passing the low-voltage reception signal that is equal to the number of transducer elements of the ultrasound transducer array (e.g.. eight).

[0085] The low-voltage reception signal can be transmitted to the substrate from the high-voltage chiplet (e.g., using electrical connections between the high-voltage chiplet and substrate). The substrate can pass the low-voltage reception signal to the low- voltage chiplet. The substrate can include a number of channels for passing the low-voltage reception signal that is equal to or greater than the number of transducer elements of the ultrasound transducer array (e.g., eight). In some embodiments, the substrate can include a high density routing die used to transmit the low-voltage reception signal. In some embodiments, the high density routing die can include multiple layers of channels. In one embodiment, the high density routing die includes four layers of channels, each layer capable of passing approximately 1250 signals. As such, the high density routing die is capable of transferring large amounts of information, quickly, which can be helpful for some ultrasound applications.

[0086] At block 458, the low-voltage chiplet generates a sensor signal. The low- voltage chiplet can process the low-voltage reception signal to generate the sensor signal.The low-voltage chiplet can include attenuators, amplifiers, filters, beamforms, and / or other ultrasound processing components to perform this processing.

[0087] The low-voltage chiplet can process the analog signals of the low- voltage reception signal and reduce the number of signals. For example, the low-voltage chiplet may include analog beamformers that can perform sub-array beamforming (also referred to as “sub-aperture beamforming,'’ or “front-end beamforming’') that combine multiple analog signals into a single analog signal. In one embodiment, the low-voltage chiplet includes analog beamformers that can combine eight analog signals into one analog signal. The low-voltage chiplet can include analog-to-digital converters (ADC) that convert the analog signals into digital signals. In one embodiment, the low-voltage chiplet includes an ADC for every element of the ultrasound transducer array. The low-voltage chiplet can include digital beamformers that can reduce the total number of digital signals received from the ADCs. For example, the low-voltage chiplet can include eight ADCs and digital beamformers that reduce the eight digital signals at the output of the ADCs to a single LVDS and / or a single digital signal. The low-voltage chiplet may process the analog signals in other ways. For example, attenuators on the low-voltage chiplet can reduce high amplitude signals (e.g., signals above a threshold voltage, such as 1.2 V), low noise amplifiers on the low-voltage chiplet can amplify signals below a threshold, and filters can filter out frequencies above and / or below a desired. However, the low-voltage chiplet is not limited by these examples and can otherwise process the analog signals.

[0088] At block 460, the ultrasound electronics assembly can transmit the sensor signal to a controller device. The sensor signal can be a result of the processing performed by the low-voltage chiplet. In some embodiments, the sensor signal can include filtered and beamformed analog signals. In some embodiments, the sensor signal can include digital signals from ADCs and / or digital beamformers of the low-voltage chiplet. The sensor signal can be transmitted to the substrate (e.g., through electrical connections between the low-voltage chiplet and the substrate). The substrate may provide electrical connection to a connection interface and / or a cable, such that the sensor signal is communicated from the ultrasound electronics assembly to the control device. In some embodiments, the control device is the control device 102 of FIGS. 1 A and IB. The control device can convert the sensor signal into a display signal.

[0089] FIG. 5A illustrates a perspective view of an alternative embodiment 500 of an ultrasound electronics assembly, such as ultrasound electronics assembly 204. In the embodimentOO, the ultrasound transducer array 206 and the high-voltage chiplet 210 arecoupled to a flexible printed circuit card (“FPC”) 501. In embodiment 500, the FPC 501 facilitates electrical connection between the ultrasound transducer array 206 the high- voltage chiplet 210. Embodiment 500 reduces the overall material of the substrate 214 but may increase the complexity of manufacture. According to various embodiments the FPC 501 may be approximately 25 microns thick. Acoustic matching material may be provided on a side of the FPC 501 opposite the transducer array 206. In some embodiments the acoustic matching may be approximately 200 microns thick.

[0090] FIG. 5B illustrates a perspective view of a second alternative embodiment 550 of an ultrasound electronics assembly, such as ultrasound electronics assembly 204. In the embodiment 550, a combined pulser and high-voltage chiplet 502 replaces the high-voltage chiplet 210 and low-voltage chiplet 212 of FIG. 2B. Embodiment 550 reduces the number of connection pathways and / or high density routing dies needed. However, embodiment 550 may have some drawbacks including increased cost of components, decreased thermal dissipation, increased noise interference, etc.

[0091] FIG. 6 illustrates an example ultrasound transducer array 600 that can be utilized in an ultrasound electronics assembly, such as ultrasound electronics assembly 204. The ultrasound transducer array 600 can be a ID transducer array of ultrasonic transducer elements 602. In some embodiments, the transducer array is a ID transducer array of eight ultrasonic transducer elements 602. The ultrasound transducer array 600 has a length (W3) and a height (W4). The length (W3) may be greater than the height (W4). In a non-limiting example, the length (W3) may be about 500 microns and / or the height (W4) may be about 200 microns. These number are merely examples, and other dimensions can also be used. For example, the length (W3) may be less than or greater than about 500 microns. Also, the height (W4) may be less than or greater than about 200 microns.

[0092] As previously described, each ultrasonic transducer elements 602 of the ultrasound transducer array 600 can receive an electrical signal (e.g., a high-voltage pulse) to produce an ultrasound signal. The ultrasound signals generated by the ultrasonic transducer elements 602 may interfere to produce ultrasound beams. By sending a high- voltage pulse to the ultrasound transducer array 600 the resulting ultrasound beam can be controlled. For example, variable high-voltage pulses to the ultrasound transducer array 600 may be used to form an ultrasound beam along a lateral direction. The depth of the ultrasound beam may also be controlled using high-voltage pulses. In various embodiments, the high-voltage pulse can in the range of 10-60 Volts peak-to-peak (VPP), orin some cases even a higher-voltage (e.g., in some applications the high-voltage signal may reach or exceed 200 VPP).

[0093] Each ultrasonic transducer elements 602 may generate an electrical signal (e.g., an analog signal) from reflected ultrasound signals. As such, the ultrasound transducer array 600 can generate ultrasound beams and sense the resulting reflected ultrasound signals to perform IVUS. The electrical signal the transducer array 600 produces when receiving ultrasound signals can have a significantly attenuated voltage compared to the high-voltage pulses used to generate ultrasound signals. In some instances, the electrical signal generated from reflected ultrasound signals may have voltages in the order of magnitude of mV or pV. For example, some of the returned ultrasound signals may be reflected from more distant target or from a target with a low reflectivity. In this example, the generated electrical signal associated with this target may be less than 10 pV. As such, multiple orders of magnitude may separate the voltages of the high-voltage pulses and the low-voltage signals generated by the ultrasound transducer array 600 when receiving ultrasound signals.

[0094] The ultrasound transducer array 600 may operate in concert with other ultrasound transducer arrays. For instance, a device (e.g., a catheter tip) may utilize multiple ultrasound transducer arrays 600, arrange radially outward, as shown in FIG. 2A. As such, the device may form multiple radially outward beams for increased sensor coverage of a lumen (e.g., a vascular vessel). Further, the multiple ultrasound transducer arrays 600 may form a single ultrasound beam, increasing the range of angles for the ultrasound beam.

[0095] FIG. 7 illustrates a perspective view of an example configuration 700 for a high density routing die 706. The high density routing die 706 may be utilized for the connection paths 216a-216c of FIGS. 2B, 3A. and 3B. In the illustrated example, the high density routing die 706 is connecting a first chiplet 702 and a second chiplet 704. In some embodiments, the first chiplet 702 and the second chiplet 704 may corresponds to the ultrasound transducer array 206, the high-voltage chiplet 210, the low-voltage chiplet 212, and / or the connection interface 218.

[0096] The first chiplet 702 may be connected to the high density routing die 706, for example, via bumps 708. Similarly, the second chiplet 704 may be connected to the high density routing die 706, for example, via bumps 710. The bumps 708 and the bumps 710 may be conductive bumps used in device packaging to connect and / or bond the device to another. For example, the bumps may be an array of solder balls used in ball grid array (BGA) packages. In some instances, the bumps 708 and the bumps 710 may otherwiseconnect the high density routing die 706 to the first chiplet 702 and second chiplet 704. For example, the bumps 708 and the bumps 710 may include, but are not limited to, solder pads, pin connectors, though-holes, surface mount leads, pin grid arras, land grid arrays, and / or leads In a non-limiting example, bumps 708 and bumps 710 may each be formed by a grid of 110x45 bumps. The number of the bumps is merely an example and other numbers can also be used. For example, less than 110x45 bumps or more than 110x45 bumps can be used. Each bump in the bumps 708 and bumps 710 may include or be formed of a conductive or semiconductive material. The high density routing die 706 may include a high density connection pathway 712. In some embodiments, the high density connection pathway 712 comprises 4 layers of connections, each layer that can transfer approximately 1250 signals. The high density connection pathway 712 may include control buses and power delivery connections.

[0097] In non-limiting embodiments the high density routing die 706 includes an overlap dimension W5 of 2mm, a bridge dimension W6 of 1mm, and a total width W7 of 5mm. Again, these numbers are merely examples and other numbers can also be used.

[0098] FIG. 8 schematically depicts a high-voltage chiplet 800 used in a system for intravascular ultrasound. The high-voltage chiplet 800 may include a pulse generator 802, a beamformer unit 804, transmit / receive (“T / R’’) switches 806, and communication interface 808. As previously described, a high-voltage chiplet 800 may send a high-voltage pulse to an ultrasound transducer array to produce an ultrasound beam in a desired direction and intensity. The pulse generator 802 can receive a low-voltage transmission signal with information associated with the high-voltage pulse (e.g. frequency information, directional information, duration information, and / or other information) and produce a corresponding high-voltage pulse. The high-voltage chiplet 800 shown in FIG. 8 is merely an example pulser, and certain elements may be modified or removed, two or more elements combined into a single element, and / or other elements or equipment may be added.

[0099] To generate the beamforming signal, the high-voltage chiplet 800 mayreceive one or more signals from the communications interface 808. the communication interface 808 may be a connection to a high density routing die or a substrate as previously describe. The signals received at the communication interface 08 can include analog signals (e.g., radio frequency signals) and digital signals that each can form a portion of the low- voltage transmission signal. The received signals can be utilized by the beamformer unit 804 to generate a signal used by the pulse generator 802. For example, the beamformer unit 804 may receive low-voltage transmission signals from the communication interface 808and generate a signal for use with the pulse generator 802. The pulse generator 802 may use the signal and generate a high-voltage pulse and transmit the high-voltage pulse to a transducer array.

[0100] As previously described, the high-voltage chiplet 800 may also receive a signal, such as a low-voltage reception signal, from an ultrasound transducer arraycorresponding to sensed ultrasound signals. The low-voltage reception signal may be sent directly to the communication interface 808. In some embodiments, the beamformer unit 804 may also convert the received signals into a beamform to be sent back through the communications interface 808. The received signals may be low-voltage signals(e.g., signals of less than 10 V, 1 V, 1 mV, or less than 10 pV).. The T / R switches 806 may be configured to switch a pathway from the high-voltage chiplet 800 to each element of the ultrasound transducer array to a transmission configuration or a reception configuration. For example, the T / R switches 806 may alternate a pathway from the high-voltage chiplet 800 from a configuration to transmit a high-voltage signal to a configuration to receive a low-voltage reception signal. The T / R switches 806 may also alter the connection pathways in the 800. For example, in some embodiments, the when the T / R switches 806 are in a reception configuration, low-voltage reception signals are directed directly from the transducer elements to the communication interface 808.

[0101] FIG. 9 schematically depicts a low-voltage chiplet 900 used in a system for intravascular ultrasound. The low-voltage chiplet 900 can include an attenuator 902. a low noise amplifier 904, a high pass filter 906, a low pass filter 908, a beamformer unit 910, thermal controls 912, and a communication interface 914. The low-voltage chiplet 900 shown in FIG. 9 is merely an example AFE, and certain elements may be modified or removed, two or more elements combined into a single element, and / or other elements or equipment may be added.

[0102] As previously described, the low-voltage chiplet 900 may work together with a high-voltage chiplet to generate a beamforming signal that is converted into a high- voltage pulse to direct an ultrasound beam. The low-voltage chiplet 900 may receive signals from the communication interface 914 that indicate a desired direction for an ultrasound beam. The low- voltage chiplet 900 may utilize the beamformer unit 910 to form at least a part of the signal used in beamforming the high-voltage pulse. For example, the beamformer unit 910 may receive analog signals, digital signals low voltage differential signaling C'LVDS”) signals, control signals, and / or power delivery from the communication interface 914 and generate at least a part of the signal used in beamformingthe high-voltage pulse. The low-voltage chiplet 900 may send a low-voltage signal along with other analog signals, digital signals, LVDS signals, control signals, and / or power delivery to a highOvoltage chiplet via the communication interface 914. In some embodiments, the received signals and or sent signals are further processed using at least some of the attenuator 902, the low noise amplifier 904, the high pass filter 906, and / or the low pass filter 908.

[0103] The thermal controls 912 may sense and / or control the thermal operation of the intravascular ultrasound device. For example, the thermal controls 912 may generate warning signals and / or otherwise to operate to reduce temperatures the exceed operating condition and / or can harm a patient. In some embodiments, the thermal operator will cause beamforming signals to halt if sensor temperatures exceed a threshold value.

[0104] The low-voltage chiplet 900 may also receive a portion of an output beamform corresponding to a received or return ultrasound signal from a high-voltage chiplet via the communication interface 914. For example, the high-voltage chiplet mayreceive a low-voltage ultrasound signal (e.g., a low-voltage reception signal) from a transducer array and pass the low-voltage ultrasound signal directly to the low-voltage chiplet 900 via the communication interface 914. In another example, a high-voltage chiplet may receive an ultrasound signal, form a portion of the output beamform, and send the portion of the output beamform to the low-voltage chiplet 900 via the communication interface 914. The low- voltage chiplet 900 may process the portion of the output beamform using the beamformer unit 910 to form a complete output beamform signal (also referred to herein as a “sensor signal”).. The low-voltage chiplet 900 may send the output beamform signal to an external device, such as the control device 102 described in FIGS. 1A and IB.

[0105] The beamformer unit 910 can process analog signals (e.g., low-voltage reception and reduce the number of signals. For example, the beamformer unit 910 may include analog beamformers that can perform sub-array beamforming (also referred to as “sub-aperture beamforming,” or “front-end beamforming”) that combines multiple analog signals into a single analog signal. In one embodiment, the beamformer unit 910 includes analog beamformers that can combine 48 analog signals into one analog signal. The beamformer unit 910 can include analog-to-digital converters (ADC) that convert the analog signals into digital signals. In one embodiment, the beamformer unit 910 includes an ADC for every element of the ultrasound transducer array. The beamformer unit 910 can include digital beamformers that can reduce the total number of digital signals received from the ADCs. For example, the beamformer unit 910 can include 4608 ADCs and digitalbeamformers that reduce the 4608 digital signals at the output of the ADCs to 96x2 digital signals. In some embodiments the portion of the output beamform and / or the complete output beamform signal may be further processed using at least some of the attenuator 902, the low noise amplifier 904, the high pass filter 906, and / or the low pass filter 908. In some embodiments, the sent output beamform signal may correspond to 10 low voltage signals sent to the device.FIG. 10 illustrates a flow diagram of a process 1000 for forming an ultrasonic transducer assembly. The steps of process 1000 described in association with FIG. 10 can be performed in a different sequence, can be added, merged, or left out altogether (e.g., not all described acts or events are necessary' for the process). Moreover, in certain embodiments, functions, acts or events can be performed concurrently. The steps of process 1000 can be performed utilizing known techniques in the art, such as semiconductor device fabrication techniques.

[0106] At block 1002, a substrate is fabricated. For example, a substrate, such as substrate 214 may be formed. In some embodiments the substrate is an FCBGA. In some embodiments, forming the substrate includes forming high density routing, such as a high density routing die, in the substrate. At block 1004, an high-voltage chiplet is assembled. For example, an high-voltage chiplet, such as low-voltage chiplet 212 may be formed. At block 1006, a high-voltage chiplet is assembled. For example, a high-voltage chiplet. such as high-voltage chiplet 210 may be formed. At block, 1008 a transducer array is assembled. For example, an ultrasound transducer array, such as the ultrasound transducer array 206 may be formed.

[0107] At block 1010, the elements are bonded to the substrate. For example, the high-voltage chiplet, the high-voltage chiplet and the ultrasound transducer array 206 may be bonded to the substrate. In some embodiments, die-to-die bonding techniques are utilized to bond the elements to the substrate.

[0108] The foregoing description details certain embodiments of the systems, devices, and methods disclosed herein. It will be appreciated, however, that no matter how detailed the foregoing appears in text, the sy stems, devices, and methods can be practiced in many ways. As is also stated above, it should be noted that the use of particular terminology7when describing certain features or aspects of the invention should not be taken to imply that the terminology' is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the technology with which that terminology is associated.

[0109] It will be appreciated by those skilled in the art that various modifications and changes may be made without departing from the scope of the described technology. Such modifications and changes are intended to fall within the scope of the embodiments. It will also be appreciated by those of skill in the art that parts included in one embodiment are interchangeable with other embodiments; one or more parts from a depicted embodiment can be included with other depicted embodiments in any combination. For example, any of the various components described herein and / or depicted in the figures may be combined, interchanged or excluded from other embodiments.

[0110] As is also stated above, it should be noted that the use of particular terminology when describing certain features or aspects should not be taken to imply that the terminology is being re-defined herein to be restricted to including any specific characteristics of the features or aspects of the technology with which that terminology is associated. Conditional language such as, among others, “can,” “could,” “might” or “may,” unless specifically stated otherwise, are otherwise understood within the context as used in general to convey that certain embodiments include, while other embodiments do not include, certain features, elements and / or steps. Thus, such conditional language is not generally intended to imply that features, elements and / or steps are in any w ay required for one or more embodiments or that one or more embodiments necessarily include logic for deciding, w ith or w ithout user input or prompting, whether these features, elements and / or steps are included or are to be performed in any particular embodiment.[Ol H] Headings are included herein for reference and to aid in locating various sections. These headings are not intended to limit the scope of the concepts described with respect thereto. Such concepts may have applicability throughout the entire specification.

[0112] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and / or position to indicate that the value and / or position described is within a reasonable expected range of values and / or positions. For example, a numeric value may have a value that is + / - 0. 1% of the stated value (or range of values), + / - 1% of the stated value (or range of values), + / - 2% of the stated value (or range of values), + / - 5% of the stated value (or range of values), + / - 10% of the stated value (or range of values), etc. Any numerical values given herein should also be understood to include about or approximately that value, unless the context indicates otherwise.

[0113] For example, if the value “10” is disclosed, then “about 10” is also disclosed. Any numerical range recited herein is intended to include all sub-ranges subsumed therein. It is also understood that when a value is disclosed that “less than or equal to” the value, “greater than or equal to the value” and possible ranges between values are also disclosed, as appropriately understood by the skilled artisan. For example, if the value “X” is disclosed the “less than or equal to X” as well as “greater than or equal to X” (e.g.. where X is a numerical value) is also disclosed. It is also understood that the throughout the application, data is provided in a number of different formats, and that this data, may represent endpoints or starting points, and ranges for any combination of the data points. For example, if a particular data point “10” and a particular data point “15” may be disclosed, it is understood that greater than, greater than or equal to, less than, less than or equal to, and equal to 10 and 15 may be considered disclosed as well as between 10 and 15. It is also understood that each unit between two particular units may be also disclosed. For example, if 10 and 15 may be disclosed, then 11, 12, 13, and 14 may be also disclosed.

[0114] Disjunctive language such as the phrase “at least one of X, Y. or Z,” unless specifically stated otherwise, is otherwise understood with the context as used in general to present that an item, term, etc., may be either X, Y, or Z, or any combination thereof (e.g., X, Y, and / or Z). Thus, such disjunctive language is not generally intended to, and should not. imply that certain embodiments require at least one of X, at least one of Y, or at least one of Z to each be present.

[0115] The phrase “based on” does not mean “based only on,” unless expressly specified otherwise. In other words, the phrase “based on” describes both “based only on” and “based at least on.” Unless otherwise explicitly stated, articles such as “a” or “an” should generally be interpreted to include one or more described items. Accordingly, phrases such as “a device configured to” are intended to include one or more recited devices.

[0116] It will be appreciated by those skilled in the art that various modifications and changes may be made without departing from the scope of the described technology. Such modifications and changes are intended to fall within the scope of the embodiments. It will also be appreciated by those of skill in the art that parts included in one embodiment are interchangeable with other embodiments; one or more parts from a depicted embodiment can be included with other depicted embodiments in any combination. For example, any of the various components described herein and / or depicted in the figures may be combined, interchanged or excluded from other embodiments.

[0117] The above description also discloses methods and materials of the present application. The IVUS catheter device described herein may be susceptible to modifications in the methods and materials, as well as alterations in the fabrication methods and equipment. Such modifications will become apparent to those skilled in the art from a consideration of this disclosure or practice of the invention disclosed herein. Consequently, it is not intended that this invention be limited to the specific embodiments disclosed herein, but that it cover all modifications and alternatives coming within the true scope and spirit of the invention as embodied in the attached claims. Applicant reserves the right to submit claims directed to combinations and sub-combinations of the disclosed inventions that are believed to be novel and non-obvious. Inventions embodied in other combinations and subcombinations of features, functions, elements and / or properties may be claimed through amendment of those claims or presentation of new claims in the present application or in a related application. Such amended or new claims, whether they are directed to the same invention or a different invention and whether they are different, broader, narrower or equal in scope to the original claims, are to be considered within the subject matter of the inventions described herein.Examples

[0118] Disclosed herein are additional examples of systems and methods described herein. Any of the examples in this disclosure may be combined in whole or in part. Any of the systems described in the examples may implement any of the methods, processes, and / or the like described herein and any of the methods described in the examples may be implemented by any of the systems described herein. Some aspects of the embodiments discussed above are disclosed in further detail in the additional examples, which are not in any way intended to limit the scope of the present disclosure. Those in the art will appreciate that many other embodiments also fall within the scope of the invention, as it is described herein above and in the claims. Any of the examples may include fewer or greater components or steps. Further, components and / or method steps described in the examples can be replaced with other components and / or method steps.

[0119] Example 1: An ultrasound catheter assembly comprising: a catheter adapted to be inserted into a body of a patient along a lumen, a proximal end of the catheter configured to be disposed outside the body of the patient, a distal end of catheter configured to be inserted into the body of the patient; a round face on the distal end. defining a radial center; and a plurality of ultrasound electronics assemblies positioned in the distal end ofthe catheter, the plurality of ultrasound electronics assemblies at least partially surrounding the radial center of the round face on the distal end. each of the plurality of ultrasound electronics assemblies comprising: an ultrasound transducer array configured to: generate an ultrasound signal based on at least one of a first voltage signal or a second voltage signal, the first signal and the second signal being different from each other, transmit the ultrasound signal to an internal vascular vessel of the patient while the ultrasound transducer array is disposed within the body of the patient, and receive a return ultrasound signal returned from the internal vascular vessel of the patient; a first chip configured to generate and provide the first voltage signal to the ultrasound transducer array; a second chip configured to generate and provide the second voltage signal to the first chip; and a substrate configured to: accommodate the ultrasound transducer array, the first chip and the second chip, and provide a signal path between the first chip and second chip to electrically connect the first chip and second chip.

[0120] Example 2: The ultrasound catheter assembly of Example 1, wherein the plurality of ultrasound electronics assemblies fully surround the radial center of the round face on the distal end.

[0121] Example 3: The ultrasound catheter assembly of Example 1, wherein the plurality7of ultrasound electronics assemblies comprise at least four ultrasound electronics assemblies.

[0122] Example 4: The ultrasound catheter assembly of Example 1, wherein the plurality of ultrasound electronics assemblies comprise at least six ultrasound electronics assemblies.

[0123] Example 5: The ultrasound catheter assembly of Example 1, wherein the plurality of ultrasound electronics assemblies comprise at least eight ultrasound electronics assemblies.

[0124] Example 6: The ultrasound catheter assembly of Example 5, wherein at least two of the at least eight ultrasound electronics assemblies contact each other.

[0125] Example 7: The ultrasound catheter assembly of Example 1, wherein the substrate comprises one or more high density routing dies.

[0126] Example 8: The ultrasound catheter assembly of Example 1, further comprising a cable extending from the plurality7of ultrasound electronics assemblies towards the proximal end of the catheter.

[0127] Example 9: The ultrasound catheter assembly of Example 8, wherein the cable is configured to electrically connect the plurality of ultrasound electronics assemblies to a controller configured to be disposed outside the body of the patient.

[0128] Example 10: The ultrasound catheter assembly of Example 1, wherein the first chip, second chip, and the ultrasound transducer array are bonded to the substrate.

[0129] Example 11: The ultrasound catheter assembly of Example 10, wherein the first chip, second chip, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding.

[0130] Example 12: The ultrasound catheter assembly of Example 11, wherein the die-to-die bonding includes a plurality of conductive bumps.

[0131] Example 13: The ultrasound catheter assembly of Example 1, wherein the substrate comprises an organic material.

[0132] Example 14: The ultrasound catheter assembly of Example 1, wherein the ultrasound transducer array comprises a one dimensional ("ID") array of ultrasonic transducer elements.

[0133] Example 15: An ultrasound transducer for use with a catheter, the ultrasound transducer comprising: a plurality of ultrasound electronics assemblies configured to be positioned in a distal end of a catheter and configured to be inserted into a body of a patient, each of the plurality of ultrasound electronics assemblies comprising: an ultrasound transducer array configured to: generate an ultrasound signal based on at least one of a first voltage signal or a second voltage signal, the first signal and the second signal being different from each other, the second voltage signal including at least a portion of a control signal received from a catheter controller, transmit the ultrasound signal to an internal vascular vessel of the patient while the ultrasound transducer array is disposed within the body of the patient, and receive a return ultrasound signal returned from the internal vascular vessel of the patient; a first chip configured to generate and provide the first voltage signal to the ultrasound transducer array; a second chip configured to generate and provide the second voltage signal to the first chip; and a substrate configured to: accommodate the ultrasound transducer array, the first chip and the second chip, and provide a signal path between the first chip and second chip to electrically connect the first chip and second chip.

[0134] Example 16: The ultrasound transducer of Example 15, wherein the plurality of ultrasound electronics assemblies comprise at least four ultrasound electronics assemblies.

[0135] Example 17: The ultrasound transducer of Example 15, wherein the plurality of ultrasound electronics assemblies comprise at least six ultrasound electronics assemblies.

[0136] Example 18: The ultrasound transducer of Example 15, wherein the plurality of ultrasound electronics assemblies comprise at least eight ultrasound electronics assemblies.

[0137] Example 19: The ultrasound transducer of Example 18, wherein at least two of the at least eight ultrasound electronics assemblies contact each other.

[0138] Example 20: The ultrasound transducer of Example 15, wherein the substrate comprises one or more high density routing dies.

[0139] Example 21: The ultrasound transducer of Example 15, wherein the first chip, second chip, and the ultrasound transducer array are bonded to the substrate.

[0140] Example 22: The ultrasound transducer of Example 21 , wherein the first chip, second chip, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding.

[0141] Example 23: The ultrasound transducer of Example 22, wherein the die- to-die bonding includes a plurality of conductive bumps.

[0142] Example 24: The ultrasound transducer of Example 15, wherein the substrate comprises organic material.

[0143] Example 25: The ultrasound transducer of Example 15. wherein the ultrasound transducer array comprises a one dimensional ("I D") array of ultrasonic transducer elements.

[0144] Example 26: The ultrasound transducer of Example 15, wherein the controller is configured to be disposed outside the body of the patient.

[0145] Example 27: A method of using an ultrasound catheter assembly, comprising: providing an ultrasound catheter assembly comprising: a catheter adapted to be inserted into a body of a patient along a lumen, a proximal end of the catheter configured to be disposed outside the body of the patient, a distal end of catheter configured to be inserted into the body of the patient; a round face on the distal end, defining a radial center; a plurality of ultrasound electronics assemblies positioned in the distal end of the catheter, the plurality of ultrasound electronics assemblies at least partially surrounding the radial center of the round face on the distal end, each of the plurality of ultrasound electronics assemblies comprising: an ultrasound transducer array configured to: generate an ultrasound signal based on at least one of a first voltage signal or a second voltage signal,the first signal and the second signal being different from each other, transmit the ultrasound signal to an internal vascular vessel of the patient while the ultrasound transducer array is disposed within the body of the patient, and receive a return ultrasound signal returned from the internal vascular vessel of the patient; a first chip configured to generate and provide the first voltage signal to the ultrasound transducer array; a second chip configured to generate and provide the second voltage signal to the first chip; and a substrate configured to: accommodate the ultrasound transducer array, the first chip and the second chip, and provide a signal path between the first chip and second chip to electrically connect the first chip and second chip; generating ultrasound signals using the plurality' of ultrasound electronics assemblies while the plurality of ultrasound electronics assemblies are disposed within the body of the patient; transmitting the ultrasound signals using the plurality ultrasound electronics assemblies toward the internal vascular vessel of the patient while the plurality of ultrasound electronics assemblies are disposed within the body of the patient; receiving ultrasound signals returned from the internal vascular vessel of the patient using the plurality ultrasound electronics assemblies while the plurality of ultrasound electronics assemblies are disposed within the body of the patient; and providing the returned ultrasound signals to a controller disposed outside the body of the patient.

[0146] Example 28: The method of Example 27, wherein the providing comprises: transmitting the returned ultrasound signals to the controller through one or more cables connected to the catheter.

[0147] Example 29: The method of Example 27, wherein the substrate comprises one or more high density routing dies.

[0148] Example 30: The method of Example 27, wherein the plurality of ultrasound electronics assemblies fully surround the radial center of the round face on the distal end.

[0149] Example 31: The method of Example 27, wherein the plurality' of ultrasound electronics assemblies comprise at least four ultrasound electronics assemblies.

[0150] Example 32: The method of Example 27, wherein in the plurality of ultrasound electronics assemblies comprise at least six ultrasound electronics assemblies.

[0151] Example 33: The method of Example 27, wherein the plurality’ of ultrasound electronics assemblies comprise at least eight ultrasound electronics assemblies.

[0152] Example 34: The method of Example 33, wherein at least two of the at least eight ultrasound electronics assemblies contact each other.

[0153] Example 35: The method of Example 27, wherein the first chip, second chip, and the ultrasound transducer array are bonded to the substrate.

[0154] Example 36: The method of Example 27, wherein the first chip, second chip, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding.

[0155] Example 37: The method of Example 36, wherein the die-to-die bonding includes a plurality of conductive bumps.

[0156] Example 38: The method of Example 27, wherein the substrate comprises an organic material.

[0157] Example 39: The method of Example 27, wherein the ultrasound transducer array comprises a one dimensional C I D ') array of ultrasonic transducer elements.

Claims

WHAT IS CLAIMED IS:

1. An intravascular ultrasound (IVUS) probe located on a distal end of a catheter and configured to generate and process ultrasound signals, the IVUS probe comprising: a plurality of IVUS electronic assemblies configured to at least partially surround a radial center at a distal end of the IVUS probe, each IVUS electronic assembly comprising: a first chiplet configured to generate a high-voltage pulse based on a low- voltage transmission signal; a second chiplet configured to generate the low-voltage transmission signal and to process a low-voltage reception signal to reduce a number of channels of the low-voltage reception signal: an ultrasound transducer array configured to: receive the high-voltage pulse from the first chiplet, generate an ultrasound signal based on the high-voltage pulse, and generate the low- voltage reception signal from ultrasound waves; and a substrate configured to: couple to the ultrasound transducer array, the first chiplet and the second chiplet, and provide a signal path between the first chiplet and the second chiplet.

2. The IVUS probe of Claim 1. wherein the first chiplet is configured to provide the low-voltage reception signal to the second chiplet without processing the low-voltage reception signal.

3. The IVUS probe of Claim 1, wherein the plurality of IVUS electronic assemblies fully surround the radial center at the distal end of the IVUS probe4. The IVUS probe of Claim 1, wherein the plurality of IVUS electronic assemblies comprise at least four ultrasound electronics assemblies.

5. The IVUS probe of Claim 1, wherein the plurality of IVUS electronic assemblies comprise at least six ultrasound electronics assemblies.

6. The IVUS probe of Claim 1. wherein the plurality of IVUS electronic assemblies comprise at least eight ultrasound electronics assemblies.

7. The IVUS probe of Claim 1, wherein the substrate comprises one or more high density routing dies.

8. The IVUS probe of Claim 1, wherein the first chiplet, second chiplet, and the ultrasound transducer array are bonded to the substrate.

9. The IVUS probe of Claim 8. wherein the first chiplet, the second chiplet, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding.

10. The IVUS probe of Claim 9, wherein the die-to-die bonding includes a plurality of conductive bumps.

11. The IVUS probe of Claim 1, wherein the substrate comprises an organic material.

12. The IVUS probe of Claim 1, wherein the ultrasound transducer array comprises a one dimensional array of ultrasonic transducer elements.

13. A system for intravascular ultrasound (IVUS), the system comprising: a catheter adapted to be inserted into a body of a patient along a lumen; and an IVUS probe position in a distal end of the catheter, the IVUS probe comprising: a plurality of IVUS electronic assemblies configured to at least partially surround a radial center of the IVUS probe, each IVUS electronic assembly comprising: a first chiplet configured to generate a high-voltage pulse based on a low-voltage transmission signal; a second chiplet configured to generate the low-voltage transmission signal and to process a low-voltage reception signal to reduce a number of channels of the low-voltage reception signal: an ultrasound transducer array configured to: receive the high-voltage pulse from the first chiplet, generate an ultrasound signal based on the high-voltage pulse, and generate the low-voltage reception signal from ultrasound waves; and a substrate configured to: couple to the ultrasound transducer array, the first chiplet and the second chiplet, and provide a signal path between the first chiplet and the second chiplet.

14. The system of Claim 13, wherein the first chiplet is configured to provide the low-voltage reception signal to the second chiplet without processing the low-voltage reception signal.

15. The system of Claim 13, wherein the plurality' of IVUS electronic assemblies fully surround the radial center at the distal end of the IVUS probe16. The system of Claim 13, wherein the plurality of IVUS electronic assemblies comprise at least four ultrasound electronics assemblies.

17. The system of Claim 13, wherein the plurality' of IVUS electronic assemblies comprise at least six ultrasound electronics assemblies.

18. The system of Claim 13. wherein the plurality of IVUS electronic assemblies comprise at least eight ultrasound electronics assemblies.

19. The system of Claim 13, yvherein the substrate comprises one or more high density routing dies.

20. The system of Claim 13, wherein the first chiplet, second chipl et, and the ultrasound transducer array are bonded to the substrate.

21. The system of Claim 20, yvherein the first chiplet, second chiplet, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding.

22. The system of Claim 21, wherein the die-to-die bonding includes a plurality’ of conductive bumps.

23. The system of Claim 13, wherein the substrate comprises organic material.

24. The system of Claim 13, wherein the ultrasound transducer array comprises a one dimensional array of ultrasonic transducer elements.

25. The system of Claim 13, further comprising a cable extending from the plurality of IVUS electronic assemblies towards a proximal end of the catheter.

26. The system of Claim 25, yvherein the cable is configured to electrically connect the plurality' of IVUS electronic assemblies to a controller configured to be disposed outside the body of the patient.

27. A method of performing intravascular ultrasound (IVUS), the method comprising: providing an IVUS probe located on a distal end of a catheter and configured to generate and process ultrasound signals, the IVUS probe comprising: a plurality of IVUS electronic assemblies configured to at least partially surround a radial center at the distal end of the IVUS probe, each IVUS electronic assembly comprising: a first chiplet configured to generate a high-voltage pulse based on a loyv-voltage transmission signal;a second chiplet configured to generate the low-voltage transmission signal and to process a low-voltage reception signal; an ultrasound transducer array configured to: receive the high-voltage pulse from the first chiplet, generate an ultrasound signal based on the high- voltage pulse, and generate the low-voltage reception signal from ultrasound waves; and a substrate configured to: couple to the ultrasound transducer array, the first chiplet and the second chiplet, and provide a signal path between the first chiplet and the second chiplet; generating the ultrasound signal while the IVUS probe is disposed within a body of a patient: generating the low-voltage reception signal; and processing the low-voltage reception signal.

28. The method of Claim 27, wherein the first chiplet is configured to provide the low-voltage reception signal to the second chiplet without processing the low-voltage reception signal.

29. The method of Claim 27, further comprising transmitting the processed low- voltage reception signals to a controller.

30. The method of Claim 27, wherein the substrate comprises one or more high density routing dies.

31. The method of Claim 27, wherein the plurality of IVUS electronic assemblies fully surround the radial center at the distal end of the IVUS probe.

32. The method of Claim 27, wherein the plurality of IVUS electronic assemblies comprise at least four ultrasound electronics assemblies.

33. The method of Claim 27, wherein the plurality of IVUS electronic assemblies comprise at least six ultrasound electronics assemblies.

34. The method of Claim 27, wherein the plurality of IVUS electronic assemblies comprise at least eight ultrasound electronics assemblies.

35. The method of Claim 27. wherein the first chiplet, second chiplet, and the ultrasound transducer array are bonded to the substrate.

36. The method of Claim 27, wherein the first chiplet, second chiplet, and the ultrasound transducer array are bonded to the substrate using die-to-die bonding.

37. The method of Claim 36, wherein the die-to-die bonding includes a plurality of conductive bumps.

38. The method of Claim 27, wherein the substrate comprises an organic material.

39. The method of Claim 27, wherein the ultrasound transducer array comprises a one dimensional array of ultrasonic transducer elements.

Images