Integrated steerable sheath ultrasound imaging system and method

Abstract

An ultrasound imaging system is disclosed. An ultrasound imaging system includes an intracardiac echocardiography (ICE) catheter and a transducer ring. The steerable sheath is integrated with a built-in forward looking transducer and a transducer ring located at a distal end of the steerable sheath. The transducer ring includes an array of MEMS-based pMUTs disposed over a substrate. A catheter shaft accommodates a lumen to allow passage of a puncture needle and an electronic flexible cable in communication with the at least one signal trace configured to: direct the MEMS-based pMUT array to transmit and receive an ultrasound beam via the at least one signal trace; receiving at least one signal from the MEMS-based pMUT array based on transmitting and receiving the at least one ultrasound beam; and construct at least one image of at least a portion of the heart based on the at least one signal.

Description

Technical Field

[0001] The present disclosure relates generally to the field of ultrasound imaging systems. More specifically, some embodiments relate to a steerable sheath with an integrated forward-looking intracardiac echocardiography (ICE) ultrasound catheter or a forward-looking intracardiac echocardiography (ICE) ultrasound catheter with a lumen to allow passage of a transseptal needle. The disclosed device improves the accuracy of transseptal puncture and also facilitates delivery of the device to the left atrium. Background Art

[0002] Atrial fibrillation is the most common type of cardiac arrhythmia, currently affecting approximately 2.2 million adults in the United States alone. Minimally invasive catheter-based electrophysiological (EP) interventions provide valuable information about the electrical behavior of the myocardium, which can help better diagnose and treat arrhythmias. Catheter-based radiofrequency (RF) ablation, the most common ablation therapy, is typically used to destroy a small amount of dysfunctional tissue that is causing the arrhythmia.

[0003] The use of catheter-based structural and electrophysiological procedures has recently expanded to more complex scenarios where accurate definition of variable individual cardiac anatomy is key to achieving optimal outcomes. Intracardiac echocardiography (ICE) is a unique imaging modality used for high-resolution, real-time visualization of cardiac structures, continuous monitoring of catheter position within the heart, and early identification of procedural complications such as pericardial effusion or thrombosis. ICE imaging modality also offers other benefits such as excellent patient tolerance, reduced fluoroscopy time, and the absence of general anesthesia or secondary procedures.

[0004] Since its introduction, transseptal catheterization has been used to provide left atrial access for a variety of conditions and is generally considered safe and effective. Over the past few years, an increasing number of different transcatheter interventions have required this approach. Precision in the puncture site is important not only to reduce the risk of complications but also to facilitate delivery of the device to the desired part of the left atrium and the entire procedure. To facilitate transseptal catheterization, intracardiac echocardiography and transesophageal echocardiography (TEE) have been widely used to monitor the procedure and improve the safety and accuracy of the puncture. Currently, the ICE imaging modality has largely replaced transesophageal echocardiography as the ideal imaging modality for guiding certain procedures (such as atrial septal defect closure and catheter ablation of arrhythmias) and has played a new role in other procedures, including mitral valvuloplasty, transcatheter aortic valve replacement, and left atrial appendage closure.

[0005] During electrophysiological procedures, the ICE imaging modality allows real-time images to be integrated with electroanatomical maps. The ICE imaging modality plays an important role in the assessment of arrhythmogenic substrates and is particularly suitable for mapping structures that are not visible on fluoroscopy, such as the atrial or ventricular septum, papillary muscles, and intracavitary muscle ridges. For these reasons, ICE has largely replaced transesophageal echocardiography (TEE). Furthermore, the introduction of ICE represents a major advancement in cardiac imaging and has become an integral part of various percutaneous interventional and electrophysiological procedures, with the potential to improve outcomes and reduce risks. ICE allows real-time assessment of cardiac anatomy during interventional procedures and guides catheter maneuvers related to different anatomical structures.

[0006] Compared with TEE, ICE is performed by the primary interventional operator under conscious sedation and does not require endotracheal intubation, thereby eliminating the risk of esophageal trauma and other postanesthesia consequences. Furthermore, ICE reduces fluoroscopic exposure for both the patient and the operator, which can improve outcomes, shorten procedure time, and facilitate early identification of complications such as thrombosis or pericardial effusion.

[0007] Therefore, there is a need for an improved ultrasound imaging system using a forward-looking ultrasound ICE catheter with new concepts related to improving the accuracy of transseptal puncture. Summary of the Invention

[0008] As an introduction, the preferred embodiments described below include an easy-to-use ultrasound imaging system. The ultrasound imaging system includes an intracardiac echocardiography (ICE) catheter having a longitudinal axis, a proximal end, and a distal end. In addition, a transducer ring is located at the distal end of the ICE catheter. The transducer ring includes a substrate and a micro-electromechanical (MEMS)-based piezoelectric micro-machined ultrasonic transducer (pMUT) array arranged above the substrate. The MEMS-based pMUT array is a forward accessory. The MEMS-based pMUT array includes a plurality of pMUT array elements mounted on the substrate in a circular or linear manner. In addition, the ultrasound imaging system includes a catheter shaft connected to a handle accessory at one end and to a MEMS-based pMUT array at the other end. The catheter shaft houses a lumen to allow passage of a puncture needle and an electronic flexible cable toward the proximal end of the ICE catheter. The electronic flexible cable is in communication with at least one signal trace and is configured to: direct each of the MEMS-based pMUT arrays via the at least one signal trace to transmit and receive an ultrasound beam relative to the heart, the ultrasound beam having a bandwidth that includes a predetermined fundamental mode vibration of each of the plurality of pMUT array elements, such that a single array element can simultaneously transmit and receive multiple fundamental mode vibrations; receive at least one signal from the MEMS-based pMUT array based on at least one of the transmitted and received ultrasound beams, and construct at least one image of at least a portion of the heart based on the at least one signal. Furthermore, the ultrasound imaging system includes a steerable sheath integrated with a built-in forward-looking transducer and a transducer ring located at a distal end of the steerable sheath or ICE catheter.

[0009] In addition, the ICE catheter includes a steering control unit located within the handle assembly for articulating the distal tip of the ICE catheter and aligning the face of the MEMS-based pMUT array toward an internal view including the fossa ovalis. The distal tip of the ICE catheter is coated with a material for providing electrical isolation and transmission of ultrasound signals. The ICE catheter corresponds to a mechanically flexible sheath with a marker band to allow passage into the heart and establish positioning on an X-ray image. In addition, a custom adapter is used to couple the ICE catheter to an imaging device. The custom adapter is coupled to the handle assembly using an inserter and a planar circuit board. The custom adapter is configured to transmit ultrasound transmit pulses and ultrasound receive waveforms between the ICE catheter and the imaging device. In addition, the catheter shaft encloses a plurality of separate electronic flexible cables connected between the handle assembly and the MEMS-based pMUT array. The bandwidth of the ultrasound beam includes a predetermined fundamental mode vibration of each of the plurality of pMUT array elements, such that a single array element simultaneously transmits and receives multiple fundamental mode vibrations.

[0010] In one embodiment, an intracardiac echocardiography (ICE) catheter is disclosed. The ICE catheter includes a body having a longitudinal axis and a distal end. Furthermore, a transducer ring is located at the distal end of the ICE catheter. The transducer ring includes a substrate and a microelectromechanical (MEMS)-based piezoelectric micromachined ultrasonic transducer (pMUT) array disposed above the substrate. The MEMS-based pMUT array is a forward-facing accessory. The MEMS-based pMUT array includes a plurality of transducer array elements disposed on the substrate. Furthermore, the ICE catheter includes a steerable sheath integrated with the built-in forward-looking transducer and the transducer ring located at the distal end of the ICE catheter. Furthermore, each of the plurality of transducer array elements includes individual elements of multiple diameters. Furthermore, the MEMS-based pMUT array is connected in series between at least one signal trace and a common ground. Furthermore, each transducer array element includes a plurality of transducers, wherein a first group of two or more transducers are in a first transducer array element, and a second group of two or more transducers are in the first transducer array element. Furthermore, each of the plurality of transducer array elements is connected in parallel. Furthermore, at least one first electrode is connected between the at least one piezoelectric layer and the signal conductor, and at least one second electrode is connected between the at least one piezoelectric layer and the ground conductor.

[0011] In one embodiment, an intracardiac echocardiography (ICE) imaging system is disclosed. The ICE imaging system includes an ICE catheter having a longitudinal axis, a proximal end, and a distal end. In addition, a microelectromechanical system (MEMS)-based piezoelectric micromachined ultrasonic transducer (pMUT) array is disposed within the distal end of the ICE catheter. The MEMS-based pMUT array is a forward-facing accessory and includes a plurality of MEMS-based pMUT array elements arranged on a substrate. In addition, the MEMS-based pMUT array includes pMUT cells of multiple diameters to achieve a bandwidth greater than 55%. In addition, the ICE imaging system includes a steerable sheath integrated with a built-in forward-looking transducer and a transducer ring located at the distal end of the ICE catheter. In addition, the ICE imaging system includes a catheter shaft connected to a handle accessory at one end and to the MEMS-based pMUT array at the other end, and the catheter shaft contains a lumen to allow passage of a puncture needle and an electronic flex cable toward the proximal end of the ICE catheter. The electronic flexible cable is in communication with at least one signal trace and is configured to: direct each of the plurality of MEMS-based pMUT array elements to transmit and receive ultrasound beams relative to the heart via the at least one signal trace; receive at least one signal from the plurality of MEMS-based pMUT array elements based on at least one of the transmitted and received ultrasound beams; and construct at least one image of at least a portion of the heart based on the at least one signal.

[0012] Other features and aspects of the present disclosure will become apparent from the following description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] The accompanying drawings illustrate various embodiments of systems, methods, and embodiments of various aspects of the present disclosure. It will be understood by those skilled in the art that the element boundaries (e.g., boxes, box groups, or other shapes) shown in the figures represent an example of the various boundaries of the disclosed invention. In some examples, an element can be designed as multiple elements, or multiple elements can be designed as one element. In other examples, an element shown as an internal component of an element can be implemented as an external component in another element, and vice versa. In addition, the elements may not be drawn to scale. The non-restrictive and non-exhaustive description of the present disclosure is described with reference to the following drawings. The components in the figures are not necessarily drawn to scale, on the contrary, emphasis is placed on the principles shown.

[0014] Various embodiments will be described below with reference to the accompanying drawings, which are provided to illustrate and not to limit the scope of the present disclosure in any way, wherein like names refer to like elements, and wherein:

[0015] Figure 1A is a schematic diagram of a forward-looking piezoelectric micromachined ultrasonic transducer (pMUT) circular array assembly according to an embodiment of the present disclosure;

[0016] Figure 1B is a schematic diagram of a forward-looking pMUT linear array assembly according to an embodiment of the present disclosure;

[0017] Figure 2 shows a cross-sectional view of the distal end of an ICE catheter having multiple transducer array elements according to an embodiment of the present disclosure;

[0018] Figure 3 A schematic diagram of an ultrasound imaging system according to an embodiment of the present disclosure is shown;

[0019] Figure 4A and 4B A prior art imaging system for acquiring two-dimensional image information is shown;

[0020] Figure 5 shows a perspective view of the distal end of an ICE catheter according to an embodiment of the present disclosure;

[0021] Figure 6 shows a cross-sectional view of a heart for placement of a forward-looking ICE catheter prior to transseptal puncture in accordance with an exemplary embodiment of the present disclosure;

[0022] Figure 7 shows another cross-sectional view of a heart for placement of a forward-looking ICE catheter during a transseptal puncture in accordance with an exemplary embodiment of the present disclosure;

[0023] Figure 8A schematic diagram illustrating an ICE catheter according to an embodiment of the present disclosure; and

[0024] Figure 9 Multi-channel electronic communication between an ultrasound imaging device and a MEMS-based pMUT array according to an embodiment of the present disclosure is shown.

[0025] Specific implementation mode

[0026] The components of the embodiments generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Therefore, the following more detailed description of various embodiments, as illustrated, is not intended to limit the scope of the present disclosure but is merely representative of various embodiments. Although various aspects of the embodiments are presented in the drawings, the drawings are not necessarily drawn to scale unless otherwise indicated.

[0027] Some embodiments of the present disclosure will now be discussed in detail, which illustrate all of the features of the present disclosure. The words "include," "have," "contain," and "comprise," and their alternative forms, are intended to be equivalent and open ended, in that one or more items listed in any of these words are not intended to be an exhaustive list of the one or more items, nor are they intended to be limited to the listed one or more items.

[0028] It must also be noted that as used herein and in the appended claims, the singular forms "a," "an," and "the" include plural references unless the context dictates otherwise. Although any systems and methods similar or equivalent to those described herein can be used in the practice or testing of embodiments of the present disclosure, the preferred systems and methods are now described. The terms "proximal" and "distal" are opposite terms. For example, the distal end of a device or component is the end of the component farthest from a physician during normal use. The proximal end refers to the opposite end, or the end closest to the physician during normal use.

[0029] Embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings, wherein like numerals represent like elements throughout the several figures, and wherein example embodiments are shown. However, embodiments of the present disclosure may be embodied in alternative forms and should not be construed as limited to the embodiments described herein. The examples described herein are non-limiting examples and are merely examples of other possible examples.

[0030] Reference Figure 1A , discloses a schematic diagram of a forward-looking piezoelectric micromachined ultrasonic transducer (pMUT) circular array assembly 100 according to an embodiment of the present disclosure.

[0031] The pMUT circular array assembly 100 can be coupled to an intracardiac echocardiography (ICE) catheter (not shown). The ICE catheter can have a longitudinal axis, a proximal end, and a distal end. The pMUT circular array assembly 100 can be positioned toward the distal end of the ICE catheter. The pMUT circular array assembly 100 can include a circular transducer ring 102. Furthermore, the circular transducer ring 102 can include a substrate 104 and a plurality of microelectromechanical (MEMS)-based pMUT array elements 106 mounted in a circular manner above the substrate 104. Furthermore, the MEMS-based pMUT array elements 106 are forward-facing accessories. Furthermore, the substrate 104 can include a first plurality of connections 108 positioned along the perimeter of the circular transducer ring 102. The first plurality of connections 108 can be configured to couple the MEMS-based pMUT array elements 106 in a plurality of connections. It can be noted that the plurality of connections can be series and / or parallel connections of the MEMS-based pMUT array elements 106 with the substrate 104. Furthermore, a first plurality of connections 108 are positioned along the perimeter of the circular transducer ring 102. Furthermore, the MEMS-based pMUT array element connections 108 are routed through the lumen 110 via an electronic flex cable 112. The circular transducer ring 102 can be positioned at the distal end of the ICE catheter. Furthermore, the circular transducer ring 102 can be configured to transmit an ultrasound beam forward of the distal end of the ICE catheter. Figure 8 Describe the ICE catheter.

[0032] Reference Figure 1B , discloses a schematic diagram of a forward-looking pMUT linear array assembly 114 according to an embodiment of the present disclosure.

[0033] The pMUT linear array assembly 114 may include a linear transducer ring 116. The linear transducer ring 114 may include MEMS-based pMUT array elements 118 mounted in a linear manner above the substrate 104. The MEMS-based pMUT array elements 118 may correspond to individual linear transducers. Furthermore, the linear transducer ring 116 may include a second plurality of connections 120. Furthermore, the MEMS-based pMUT array elements 118 are routed through the lumen 110 via the electronic flex cable 112. Furthermore, the linear transducer ring 116 may be located at the distal end of the ICE catheter and transmit an ultrasound beam in front of the distal end of the ICE catheter.

[0034] Figure 2 Shown is a cross-sectional view of the distal end of an ICE catheter having a MEMS-based pMUT array 202 with a plurality of transducer array elements 204 in accordance with an embodiment of the present disclosure.

[0035] The distal end of the ICE catheter can be provided with a MEMS-based pMUT array 202 having a plurality of transducer array elements 204. Furthermore, each of the plurality of transducer array elements 204 can have a plurality of individual transducer cells 206 arranged in a manner to provide a wide bandwidth of an individually focused beam. In one embodiment, the MEMS-based pMUT array 202 can be constructed from a pMUT array comprising individual elements of varying diameters. In one embodiment, to achieve a wider bandwidth of the pMUT array, pMUT cells of multiple diameters can be integrated into a single element. It can be noted that by arranging preformed pMUTs of varying diameters, a wider bandwidth can be achieved through complex interactions between the individual pMUT elements. In one embodiment, a bandwidth greater than 55% can be achieved with pMUT cells of multiple diameters. For example, in three elements, there are five different dome diameters, and each array has a different size, such as 300 μm.

[0036] Furthermore, the MEMS-based pMUT array 202 may correspond to a pMUT, and the plurality of transducer array elements 204 may correspond to a plurality of pMUT elements. In one embodiment, the plurality of pMUT elements may be directed to transmit and receive an ultrasonic beam having a bandwidth that includes a predetermined fundamental mode vibration of each of the plurality of pMUT elements, such that a single pMUT element may simultaneously transmit and receive a plurality of fundamental mode vibrations. In one embodiment, an electronic flexible cable within the catheter shaft of the ICE catheter receives at least one signal from the plurality of pMUT elements. It may be noted that the at least one signal may correspond to at least one ultrasonic beam. As Figure 3 As shown, at least one signal can be sent to an ultrasound imaging device 302 for further processing in an image processor. The image processor can construct at least one image of the heart. It can be noted that multiple pMUT elements can be used to create a single focused beam.

[0037] In an alternative embodiment, the MEMS-based pMUT array 202 may include a cover portion that presents a flat cross-section. It may be noted that the features of the MEMS-based pMUT array 202 are typical in ultrasound imaging catheters. Due to the severe space limitations imposed by the small diameter of the intracardiac catheter, the MEMS-based pMUT array 202 is typically limited to a circular phased array consisting of several individual transducer elements (such as 64 transducers or elements). The transducer has a flat surface from which sound can be ignored and echoes can be received. As is known in the art, the individual transducer elements are pulsed by the ultrasound control system so that the emitted sound waves are constructively combined into a main beam. By varying the time at which each transducer element is pulsed, as Figure 3As shown, the ultrasound imaging system 300 can render the individual beams into a focused image to obtain a 2D image. As a result, the MEMS-based pMUT array 202 transmits ultrasound waves along a plane perpendicular to the transducer array face. Therefore, the MEMS-based pMUT array 202 transmits sound along a plane perpendicular to the accessory.

[0038] Reference Figure 3 , discloses a schematic diagram of an ultrasound imaging system 300 according to an embodiment of the present disclosure.

[0039] The ultrasound imaging system 300 can be implemented for electrophysiology (EP). The ultrasound imaging system 300 can be combined with another imaging modality (such as x-ray, fluoroscopy, magnetic resonance imaging, computed tomography, or an optical system) for diagnosis and / or treatment. Both imaging modalities can scan the patient to generate images to assist the physician. By positioning markers with a known spatial relationship to the ultrasound scan in the image of the other modality, data from the different modalities can be aligned. In other embodiments, the ultrasound imaging system 300 can use a catheter without markers and / or without other imaging modalities. In one embodiment, the ultrasound imaging system 300 can utilize a microelectromechanical (MEMS) transducer array defined as a piezoelectric micromachined ultrasonic transducer (pMUT) or other types of MEMS transducers interconnected using matching flexible circuits. In one embodiment, the ultrasound imaging system 300 can correspond to an intracardiac echocardiography (ICE) imaging system. In one embodiment, the ultrasound imaging system 300 can correspond to an intravascular MEMS ultrasonic transducer that utilizes a high-density flexible circuit for all transmission and electrical interconnections. In one embodiment, ultrasound imaging system 300 can be used to treat patients with cystic fibrosis (CF). It is noted that the use of a high-density flexible circuit can achieve highly repeatable and stable transmission and return signals. Furthermore, the high-density flexible circuit transmission line can transmit power from one end of ultrasound imaging system 300 to the other, remote end.

[0040] Ultrasound imaging system 300 may include an imaging device 302 coupled to an ICE catheter 304 via a communication channel 306. In one embodiment, communication channel 306 may be a custom adapter having a cable and bus connection or multiple connections. Hereinafter, communication channel 306 may be referred to as custom adapter 306. In one embodiment, ICE catheter 304 may correspond to an ultrasound catheter.

[0041] ICE catheter 304 may be positioned within a chamber of the patient's heart, and imaging device 302 may receive at least one signal from ICE catheter 304. The at least one signal may be transmitted from ICE catheter 304 to imaging device 302 via custom adapter 306. Additionally, imaging device 302 may include an image processor 308, a transmit beamformer 310, a receive beamformer 312, and a display 314.

[0042] The image processor 308 can be configured to generate a two-dimensional (2D) image based on data received from the ICE catheter 304. In one embodiment, the image processor 308 can be configured to receive a focus signal from the receive beamformer 312. The image processor 308 can render the data to construct an image or image sequence. In one embodiment, the image can be a three-dimensional (3D) representation, such as a 2D image rendered from a viewing direction selected by a user or processor. In one embodiment, the image processor 308 can be a detector, a filter, a processor, an application specific integrated circuit, a field programmable gate array, a digital signal processor, a control processor, a scan converter, a three-dimensional image processor, a graphics processing unit, an analog circuit, a digital circuit, or a combination thereof. The image processor 308 can receive the beamformed data and generate an image for display on the display 314. It can be noted that the generated image is associated with a two-dimensional (2D) scan. Alternatively, the generated image can be a three-dimensional (3D) representation.

[0043] The image processor 308 can be programmed for hardware-accelerated two-dimensional reconstruction. The image processor 308 can store processed data and image sequences of at least one signal in a memory. In one embodiment, the memory can be a non-transitory computer-readable storage medium. Instructions for implementing the processes, methods and / or techniques discussed herein are provided on a computer-readable storage medium or memory (such as a cache, buffer, RAM, removable media, hard drive or other computer-readable storage medium). Non-transitory computer-readable storage media include various types of volatile and non-volatile storage media. The functions, actions or tasks shown in the figures or described herein are performed in response to one or more groups of instructions stored in or on a computer-readable storage medium. The functions, actions or tasks are independent of a particular type of instruction set, storage medium, processor or processing strategy and can be performed by software, hardware, integrated circuits, firmware, microcode, etc., operating alone or in combination.

[0044] Transmit beamformer 310 may be configured to transmit an electrical signal or electrical pulse in the form of at least one signal toward ICE catheter 304. Receive beamformer 312 may be configured to receive the electrical signal or electrical pulse from ICE catheter 304. In one embodiment, transmit beamformer 310 and receive beamformer 312 may facilitate transmit beamforming techniques to focus energy to a receiver, thereby improving a signal-to-noise ratio (SNR) of at least one signal, and then transmit the at least one signal to image processor 308.

[0045] The display 314 can be configured to display an image or sequence of images on the screen during or after the data is rendered by the image processor 308. The image can be a three-dimensional (3D) representation, such as a two-dimensional image rendered from a viewing direction selected by the user or processor. Alternatively, the image can be one or more two-dimensional images representing planes in the volume. In one embodiment, the display 314 can be part of the imaging device 302 or remote, such as a networked display. In one embodiment, the display 314 can be a cathode ray tube (CRT), liquid crystal display (LCD), projector, plasma, or other display device now known or later developed.

[0046] Reference Figure 4A and 4B , discloses a prior art imaging system 400. The imaging system 400 can be used for diagnosis and / or treatment in conjunction with another imaging modality, such as x-ray, fluoroscopy, magnetic resonance imaging, computed tomography, or an optical system. It can be noted that the imaging modality scans the patient to generate images to assist the physician. In addition, the imaging system 400 provides ultrasound transmit pulses 402 and an ultrasound receive path 404 for connection to an ultrasound transducer (not shown). The ultrasound transmit pulses 402 can send ultrasound signals from the imaging system 400 to an object, such as a patient's heart. In addition, the ultrasound receive path 404 can create a waveform based on at least one of the ultrasound signals. Thereafter, the imaging system 400 can convert the received ultrasound signals or ultrasound information into a two-dimensional (2D) image of the object or a portion of the object.

[0047] Reference Figure 5 , discloses a perspective view of the distal end of an ICE catheter 304 according to an embodiment of the present disclosure.

[0048] The ICE catheter 304 can include a catheter shaft 502 containing a lumen 110. The lumen 110 can allow passage of an introducer needle (not shown) and a flexible cable (not shown). It can be noted that the flexible cable transmits ultrasound signals between the transducer array 504 and the adapter 306. The transducer array 504 can include MEMS-based pMUT array elements 106 arranged along the periphery of the circular transducer ring 102.

[0049] Reference Figure 6 , a cross-sectional image of a heart 600 with a forward-looking ICE catheter 304 placed prior to transseptal puncture, according to an exemplary embodiment of the present disclosure.

[0050] ICE catheter 304 can be positioned within right atrium 602 of heart 600. Furthermore, ICE catheter 304 can include distal tip 604. Distal tip 604 of ICE catheter 304 can be inserted into right atrium 602 via the inferior vena cava (not shown). Movement of distal tip 604 of ICE catheter 304 within right atrium 602 can be controlled by a steering control unit (not shown) of ICE catheter 304 to position the distal tip 604 for imaging fossa ovalis 606.

[0051] Reference Figure 7 , discloses another cross-sectional view of a heart 600 for placement of a forward-looking ICE catheter 304 during a transseptal puncture, according to an exemplary embodiment of the present disclosure.

[0052] The distal tip 604 of the ICE catheter 304 can be positioned within the right atrium 602 of the heart 600. The steering control unit can be actuated to advance the distal tip 604 of the ICE catheter 304 to puncture the fossa ovalis 606.

[0053] Reference Figure 8 , discloses a schematic diagram of an ICE catheter 304 according to an embodiment of the present disclosure.

[0054] The ICE catheter 304 may include a flexible sheath 802 having a marker band 804 to allow positioning on an X-ray image (not shown). The flexible sheath 802 may have a marker band 804 toward the distal end 806 of the ICE catheter 304 to allow passage to the chambers of the patient's heart 600, thereby allowing positioning on the X-ray image. It may be noted that the distal end 806 of the ICE catheter 304 may be coated with a material to provide electrical isolation and transmission of the ultrasound signal generated by the ICE catheter 304. In one embodiment, the flexible sheath 802 may be inserted into the chamber of the heart 600, and the marker band 804 may allow positioning on the X-ray image. It may be noted that the image processor 308 of the ultrasound imaging device 302 may provide a real-time 2D image of the heart using the allowed positioning on the X-ray image. In one embodiment, the flexible sheath 802 may correspond to the catheter shaft 304 to allow passage into the heart, thereby achieving positioning on the X-ray image. In one embodiment, a patient with CF can be treated with an ICE catheter 304 that is coated with an electrical isolator to transmit the ultrasound signals generated by the ICE catheter 304. In one embodiment, the flexible sheath 802 can correspond to a steerable sheath integrated with a built-in forward looking transducer and a transducer ring 102 located at the distal end 806 of the steerable sheath or ICE catheter 304. It can be noted that the steerable sheath with an integrated forward looking ICE catheter 304 or with a forward looking ICE catheter with a lumen 110 can facilitate the passage of a puncture needle or a transseptal needle. The steerable sheath can facilitate maximum manipulation of the ICE catheter 304 to allow for deflection of the puncture needle. It can also be noted that the steerable sheath can facilitate access to hard to reach areas within the heart,

[0055] In addition, the ICE catheter 304 may include an electrically isolating shaft 808 toward the distal end 806 of the ICE catheter 304. The electrically isolating shaft 808 may be made of a copolymer material up to the distal end 806 of the ICE catheter 304. In one embodiment, the electrically isolating shaft 808 may be coated with Pebax material. An imaging window may allow ultrasound beams to pass back and forth to the MEMS-based pMUT array 202. In addition, the distal tip 806 of the ICE catheter 304 is coated with an electrically isolating material to provide isolation and transmission of ultrasound signals.

[0056] Furthermore, a MEMS-based pMUT array 202 may be disposed within the distal end 806 of the ICE catheter 304. The MEMS-based pMUT array 202 may include a plurality of transducer array elements 204 disposed on the substrate 104. Furthermore, the MEMS-based pMUT array 202 may be connected in series between at least one signal trace and a common ground. Furthermore, each of the plurality of transducer array elements 204 may include a plurality of transducers, wherein a first group of two or more transducers are in a first transducer array element and a second group of two or more transducers are in the first transducer array element. Furthermore, each of the plurality of transducer array elements 204 may be connected in parallel. Furthermore, each transducer array element may include at least one piezoelectric layer disposed on the substrate 104. It is noted that the at least one piezoelectric layer may include a pMUT array element. Furthermore, each transducer array element may include at least one first electrode connected between the at least one piezoelectric layer and the signal conductor. Furthermore, at least one second electrode may be connected between the at least one piezoelectric layer and the ground conductor. In one embodiment, each pMUT array element may have a predetermined geometry configured to accept a predetermined fundamental mode vibration.

[0057] In one embodiment, the MEMS-based pMUT array 202 may include a plurality of pMUTs coupled at the distal end 806 of the ICE catheter 304. It may be noted that the pMUT array is a circular phased array. In one embodiment, the two or more transducers of the first group and the two or more transducers of the second group may be connected in parallel. Furthermore, multiple transducer array elements in the plurality of transducer array elements may be grouped to function as a single array element.

[0058] Reference Figure 9 , according to an embodiment of the present disclosure, multi-channel electronic communication between the ultrasound imaging device 302 and the MEMS-based pMUT array 202.

[0059] The MEMS-based pMUT array 202 can include a plurality of transducer array elements 204 arranged on a substrate 104. In addition, each of the plurality of transducer array elements 204 can provide a wide bandwidth of a single focused beam. The MEMS-based pMUT array 202 can be coupled to the ultrasound imaging device 302 using an adapter cable. The MEMS-based pMUT array 202 disposed within the distal end 806 of the ICE catheter 304 can transmit at least one signal to the ultrasound imaging device 302 via the electronic flexible cable 902 within the catheter shaft 502. The at least one signal can be an acoustic echo emitted from the MEMS-based pMUT array 202. It can be noted that the acoustic echo of the acoustic energy can be received from the face of the MEMS-based pMUT array 202 and received at the image processor 308.

[0060] In addition, the bandwidth of the ultrasound beam can include predetermined fundamental mode vibrations of each of the plurality of transducer array elements 204, such that a single array element can simultaneously transmit and receive multiple fundamental mode vibrations. It can be noted that the plurality of transducer array elements 204 can transmit and receive ultrasound beams relative to the heart or at least a portion of the heart. In addition, the electronic flexible cable 902 within the catheter shaft 502 can be configured to receive at least one signal from the plurality of transducer array elements 204 based on at least one of the transmitted and received ultrasound beams. The ultrasound imaging device 302 can also be configured to construct at least one image of at least a portion of the heart based on the at least one signal. It can be noted that the electronic flexible cable can be configured as a transmit beamformer 310 and a receive beamformer 312 to display two-dimensional (2D) image information of the heart or at least a portion of the heart.

[0061] In one embodiment, the plurality of transducer array elements 204 may correspond to piezoelectric micromachined ultrasound transducers (pMUTs) based on microelectromechanical (MEMS). The catheter shaft 502 may be connected to a handle assembly (not shown) at one end and to the MEMS-based pMUT array 204 at the other end. An electronic flex cable 902 within the catheter shaft 502 may communicate with at least one signal trace. It may be noted that the electronic flex cable 902 may also communicate with a transmit beamformer 310 and a receive beamformer 312 via a custom adapter 306 to display two-dimensional (2D) image information of the heart to be scanned.

[0062] While certain particular structures embodying various embodiments of the invention have been shown and described herein, those skilled in the art will understand that various modifications and rearrangements of parts may be made without departing from the spirit and scope of the basic inventive concept and that such modifications and rearrangements are not limited to the particular forms shown or described herein, except as indicated by the scope of the appended claims.

Claims

1. An ultrasound imaging system, comprising: an intracardiac echocardiography (ICE) catheter having a longitudinal axis, a proximal end, and a distal end; a transducer ring positioned at the distal end of the ICE catheter, wherein the transducer ring comprises a substrate and a microelectromechanical (MEMS)-based piezoelectric micromachined ultrasonic transducer (pMUT) array disposed above the substrate, wherein the MEMS-based pMUT array is a forward-facing accessory and comprises a plurality of pMUT array elements mounted on the substrate in a circular or linear manner; a steerable sheath integrated with a built-in forward-looking transducer and the transducer ring located at the distal end of the ICE catheter; a catheter shaft connected at one end to a handle assembly and at another end to the MEMS-based pMUT array, wherein the catheter shaft houses a lumen to permit passage of an introducer needle and an electronic flex cable toward the proximal end of the ICE catheter, the electronic flex cable in communication with at least one signal trace and configured to: directing the MEMS-based pMUT array to transmit and receive ultrasound beams relative to a heart via the at least one signal trace; receiving at least one signal from the MEMS-based pMUT array based on transmitting and receiving at least one of the ultrasonic beams; and At least one image of at least a portion of the heart is constructed based on the at least one signal.

2. The ultrasound imaging system according to claim 1, wherein: Each of the plurality of pMUT array elements has transducer units of multiple diameters to achieve wide bandwidth.

3. The ultrasound imaging system according to claim 1, wherein: The transducer ring is configured to transmit an ultrasound beam forward of the distal end of the ICE catheter.

4. The ultrasound imaging system according to claim 1, wherein: The transducer ring corresponds to a circular transducer ring, wherein the MEMS-based pMUT array is mounted in a circular manner over the substrate.

5. The ultrasound imaging system according to claim 1, wherein: The transducer ring corresponds to a linear transducer ring, wherein the MEMS-based pMUT array is mounted in a linear manner above the substrate.

6. The ultrasound imaging system according to claim 1, wherein: The ICE catheter includes a steering control unit within the handle assembly for articulating a distal tip of the ICE catheter and aligning a face of the MEMS-based pMUT array toward an interior view including the fossa ovalis.

7. The ultrasound imaging system according to claim 6, wherein: The distal tip of the ICE catheter is coated with a material for providing electrical isolation and transmission of ultrasound signals.

8. The ultrasound imaging system according to claim 1, wherein: The ICE catheter corresponds to a mechanically flexible sheath with marker bands to allow passage into the heart and positioning on X-ray images.

9. The ultrasound imaging system according to claim 1, wherein: The ICE catheter is coupled to an imaging device using a custom adapter, and the custom adapter is configured to transmit ultrasound transmit pulses and ultrasound receive waveforms between the imaging device and the ICE catheter.

10. The ultrasound imaging system according to claim 1, wherein: The catheter shaft encloses a plurality of individual electronic flex cables connected between the handle assembly and the MEMS-based pMUT array.

11. The ultrasound imaging system according to claim 1, wherein: The bandwidth of the ultrasound beam includes a predetermined fundamental mode vibration of each of the plurality of pMUT array elements, such that a single array element transmits and receives the plurality of fundamental mode vibrations simultaneously.

12. An intracardiac echocardiography (ICE) catheter comprising: a body having a longitudinal axis and a distal end; a transducer ring positioned at the distal end of the ICE catheter, wherein the transducer ring comprises a substrate and a microelectromechanical (MEMS)-based piezoelectric micromachined ultrasonic transducer (pMUT) array disposed over the substrate, wherein the MEMS-based pMUT array is a forward-facing accessory and comprises a plurality of transducer array elements disposed on the substrate; a steerable sheath integrated with a built-in forward-looking transducer and the transducer ring located at the distal end of the ICE catheter, wherein each transducer array element comprises a plurality of transducers, wherein a first group of two or more transducers are in a first transducer array element and a second group of two or more transducers are in the first transducer array element, and each transducer array element is connected in parallel and comprises: at least one piezoelectric layer disposed on the substrate; at least one first electrode connected between the at least one piezoelectric layer and the signal conductor; and At least one second electrode is connected between the at least one piezoelectric layer and a ground conductor.

13. The ICE catheter of claim 12, wherein: Each of the plurality of transducer array elements is a linear phased array.

14. The ICE catheter of claim 12, wherein each of the plurality of transducer array elements is a circular phased array.

15. The ICE catheter of claim 12, wherein: The multiple transducer array elements create individual focused beams.

16. The ICE catheter of claim 12, further comprising an electrically isolating shaft covering the shaft up to an imaging window at the distal end of the body.

17. The ICE catheter of claim 16, wherein: The electrically isolated shaft uses Pebax material to cover the shaft up to the imaging accessory at the distal end of the body.

18. The ICE catheter of claim 12, wherein: The ICE catheter includes a steering control unit for articulating a distal tip of the ICE catheter and aligning a face of the MEMS-based pMUT array toward an interior view including the fossa ovalis.

19. The ICE catheter of claim 18, wherein: The distal tip of the ICE catheter is coated with a material for providing electrical isolation and transmission of ultrasound signals.

20. An intracardiac echocardiography (ICE) imaging system comprising: an ICE catheter having a longitudinal axis, a proximal end, and a distal end; a microelectromechanical (MEMS)-based piezoelectric micromachined ultrasonic transducer (pMUT) array disposed within the distal end of the ICE catheter, wherein the MEMS-based pMUT array is a forward fitting and includes a substrate and a plurality of MEMS-based pMUT array elements disposed on the substrate, and pMUT cells of multiple diameters to achieve a bandwidth greater than 55%; a steerable sheath integrated with a built-in forward-looking transducer and a transducer ring located at the distal end of the ICE catheter; as well as a catheter shaft connected at one end to a handle assembly and at another end to the MEMS-based pMUT array, the catheter shaft housing a lumen to permit passage of an introducer needle and an electronic flex cable toward the proximal end of the ICE catheter, wherein the electronic flex cable is in communication with at least one signal trace and is configured to: directing each of the plurality of MEMS-based pMUT array elements to transmit and receive ultrasound beams relative to a heart via the at least one signal trace; receiving at least one signal from the plurality of MEMS-based pMUT array elements based on transmitting and receiving at least one of the ultrasonic beams; as well as At least one image of at least a portion of the heart is constructed based on the at least one signal.

21. The ICE imaging system according to claim 20, wherein: Each of the plurality of MEMS-based pMUT array elements has transducer cells of multiple diameters to achieve wide bandwidth.

22. The ICE imaging system of claim 20, wherein the MEMS-based pMUT array corresponds to a transducer ring, wherein the plurality of MEMS-based pMUT array elements are configured to transmit an ultrasound beam forward of the distal end of the ICE catheter.

23. The ICE imaging system of claim 22, wherein: The transducer ring corresponds to a circular transducer ring, wherein the MEMS-based pMUT array is mounted in a circular manner over the substrate.

24. The ICE imaging system of claim 22, wherein: The transducer ring corresponds to a linear transducer ring, wherein the MEMS-based pMUT array is mounted in a linear manner above the substrate.

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