Intracardiac ultrasonic transducer array

Abstract

The utility model provides an intracardiac ultrasonic transducer array, and relates to the technical field of ultrasonic imaging equipment. The array comprises an outer matching layer, an inner matching layer, a piezoelectric material layer, a de-matching layer, a circuit layer and a backing layer which are sequentially stacked from top to bottom, the inner matching layer, the piezoelectric material layer and the de-matching layer are partially cut to form gaps and electrical partitions to form independent array elements, and each array element is electrically communicated with the circuit layer; a spatially adjacent independent array elements form a single equivalent sub-aperture. On the premise that the imaging requirement is met, the proper size can be ensured in a limited aperture, and complex functions are integrated.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of ultrasonic imaging equipment, more particularly to an intracardiac ultrasonic transducer array. BACKGROUND

[0002] With the increasing concern of society for health and the rapid development of clinical diagnosis and treatment technology, medical instruments represented by ultrasonic imaging have gradually become an indispensable tool for clinical treatment. Among them, intracardiac ultrasonic transducers, as a leading development direction of ultrasonic imaging technology, have shown great application potential. Intracardiac ultrasonic transducers can penetrate into the interior of the heart cavity and provide high-resolution image information, which is of great significance for the accurate diagnosis of cardiovascular diseases and the formulation of personalized treatment plans.

[0003] Intracardiac ultrasonic transducers enter the interior of the heart cavity through blood vessels, and their size is strictly limited. Too small a size of the ultrasonic transducer will result in significantly reduced intracardiac ultrasonic imaging performance, thereby blurring the imaging profile / volume and affecting the accuracy of diagnosis and treatment; and as the size increases, the operation and surgical difficulty and risk will significantly increase. Based on this, intracardiac ultrasonic transducers urgently need to achieve breakthroughs in miniaturization design and manufacturing process optimization to realize precise stacking and size optimization of the transducer, while taking into account the manufacturing cost and imaging performance. SUMMARY

[0004] The utility model aims at least to solve one of the technical problems existing in the prior art. To this end, the utility model provides an intracardiac ultrasonic transducer array, which ensures appropriate size and integrates complex functions within a limited aperture under the premise of meeting imaging requirements.

[0005] The application discloses an intracardiac ultrasonic transducer array, which comprises: an outer matching layer, an inner matching layer, a piezoelectric material layer, a de-matching layer, a circuit layer and a backing layer stacked in order from top to bottom, the inner matching layer, the piezoelectric material layer and the de-matching layer are partially cut to form gaps and electrical partitions, constituting independent elements, each element is in electrical communication with the circuit layer; A plurality of said independent elements that are spatially adjacent constitute a single equivalent sub-aperture.

[0006] In some embodiments, the size of the single equivalent sub-aperture is (M1, N1), and the A independent elements are spatially adjacent and have a length of M1 and a height of N1; M1 and N1 are both positive integers.

[0007] In some embodiments, the single equivalent sub-aperture is at least 2, and the elements with the same serial number in all equivalent sub-apertures have the same static time delay; each element in any equivalent sub-aperture has the same dynamic time delay.

[0008] In some embodiments, the number of the single equivalent sub-apertures is (M2, N2), and M2 and N2 are both positive integers.

[0009] In some embodiments, the A independent elements are two-dimensionally distributed along the length direction and the height direction of the transducer array, and the number of elements divided along the length direction and the height direction is equal or unequal.

[0010] Optionally, the length and the width of the single element are equal or unequal.

[0011] In some embodiments, the circuit layer comprises a flexible circuit layer and an application-specific integrated circuit layer stacked in sequence from top to bottom, and a de-matching layer is arranged between the piezoelectric material layer and the flexible circuit layer to absorb or scatter the backward acoustic wave of the piezoelectric material layer and connect the piezoelectric material layer and the flexible circuit layer.

[0012] In some embodiments, the ground and the input / output circuit in the flexible circuit layer are arranged at both ends of the length direction of the ultrasonic transducer array.

[0013] Optionally, the middle of the flexible circuit layer is provided with a switch board arranged in a two-dimensional array, and the switch board connects the application-specific integrated circuit pad and the ultrasonic transducer element.

[0014] In some embodiments, the application-specific integrated circuit layer comprises an excitation pulse circuit, a transmitting circuit, a receiving circuit and an analog front-end circuit, the excitation pulse circuit generates an electric pulse signal, the electric pulse signal is transmitted to the transmitting circuit for amplification and modulation; the amplified and modulated electric pulse signal drives the ultrasonic transducer array to emit ultrasonic waves, the ultrasonic waves are captured by the transducer array and converted into electric signals; the receiving circuit receives and processes the electric signals and transmits them into the analog front-end circuit for phase and amplitude control.

[0015] Optionally, the receiving circuit comprises a pre-signal amplification circuit, a gain compensation circuit and a delay circuit.

[0016] In some embodiments, the analog front-end circuit comprises a sub-aperture processor, the sub-aperture processor applies a separate static time delay to the received signals of all elements in a sub-aperture, adds the received signals to form a virtual element and realizes deflection in a specific direction.

[0017] In some embodiments, the application-specific integrated circuit comprises a circuit system same in number with the elements, and the circuit system is connected with the elements one by one through the solder joints; the size of the application-specific integrated circuit corresponding to each element is not more than the size of the element.

[0018] In some embodiments, the outer matching layer and the inner matching layer are used to couple the piezoelectric material layer and the biological tissue.

[0019] Optionally, the de-matching layer is used to decouple the piezoelectric material layer from the flexible circuit, the silicon-based application-specific integrated circuit, to simplify the thickness of the piezoelectric material and make it work under the quarter-wave mode.

[0020] The present application has the following advantages:

[0021] 1. Structural miniaturization advantage: the two-dimensional array transducer combined with the application-specific integrated circuit realizes high miniaturization, so that the multi-layer stacked transducer assembly can be installed in a small diameter catheter, and the integration of complex functions is realized in a limited space.

[0022] 2. Circuit design advantage: the design of the application-specific integrated circuit greatly simplifies the complexity of the circuit in the catheter, reduces the number of connection lines, and reduces signal loss. The sub-aperture beam forming of the analog front-end circuit makes a large number of transducer elements compatible with traditional systems and probe cables, reducing system complexity and cost. The application-specific integrated circuit is directly installed below the transducer array, significantly reducing the size, cost and parasitic capacitance of the interconnection, improving signal quality, and optimizing overall performance and cost-effectiveness.

[0023] 3. Imaging performance advantage: based on the two-dimensional array arrangement and circuit design, real-time, high-frame-rate three-dimensional imaging can be realized, taking into account imaging quality and circuit and structural optimization. The use of analog front-end and system back-end beam forming enables the array to realize large-range deflection, scanning and focusing in the length and height directions, and the beam sidelobes are significantly suppressed.

[0024] This technology has the potential to replace transesophageal echocardiography in some structural heart disease surgeries, avoiding the risks and costs associated with general anesthesia, and improving the safety and efficiency of the surgery. BRIEF DESCRIPTION OF DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained according to these drawings without creative labor for those skilled in the art.

[0026] Figure 1 is a lateral schematic view of the two-dimensional intracardiac ultrasound transducer array stack provided by the embodiment of the present application along the length and height directions;

[0027] Figure 2 is a schematic view of the ultrasound transducer array stack provided by the embodiment of the present application, wherein, Figure 2 (a) in the present application is a schematic view of the two-dimensional intracardiac ultrasound transducer array stack in planar form; Figure 2Fig. 2 is a lateral view of the transducer array stack along the width and height directions;

[0028] Figure 3 Fig. 1 is a schematic diagram of an ultrasonic transducer array provided by an embodiment of the present application, wherein, Figure 3 Fig. 2 is a lateral view of the transducer array stack along the width and height directions; Figure 3 Fig. 3 is a schematic diagram of the dynamic time delay distribution of each equivalent sub-aperture of the transducer; Figure 3 Fig. 4 is a schematic diagram of the beam profile of the transducer after two-stage time delay correction;

[0029] Figure 4 Fig. 5 is a schematic diagram of the echo receiving and imaging process of the planar two-dimensional intracardiac ultrasonic transducer provided by an embodiment of the present application, Figure 4 Fig. 6 is a schematic diagram of the analog front-end circuit, Figure 4 Fig. 7 is a flowchart of the system back-end processing;

[0030] In the figure, 1 is an outer matching layer; 2 is an inner matching layer; 3 is a piezoelectric material; 4 is a de-matching layer; 5 is a flexible circuit; 6 is an application-specific integrated circuit; 7 is a backing; S1 is an ultrasonic transducer element; S2 is a preamplifier circuit; S3 is a delay circuit; and S4 is a summing circuit. DETAILED DESCRIPTION

[0031] In order to enable personnel in the technical field to better understand the present application, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application.

[0032] In some of the processes described in the specification and the claims of the present application and the above drawings, a plurality of operations appear in a specific order, but it should be clearly understood that these operations can be executed or performed in parallel or in a sequence different from the order in which they appear in this text, and the serial numbers of the operations, such as 101, 102, etc., are only used to distinguish different operations, and the serial numbers themselves do not represent any execution order. In addition, these processes can include more or fewer operations, and the operations can be executed in sequence or in parallel. It should be noted that the "first", "second", etc. in this text are used to distinguish different messages, devices, modules, etc., and do not represent the order, nor do "first" and "second" represent different types.

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model.

[0034] like Figure 1 , 2 This is a geometric schematic diagram of a planar stack of two-dimensional intracardiac ultrasound transducer arrays. Specifically, Figure 1 This is a lateral schematic diagram of a planar two-dimensional intracardiac ultrasound transducer array stack along its length and height directions, provided in an embodiment of this utility model. Figure 2 This is a schematic diagram of the ultrasonic transducer array stack provided in an embodiment of the present invention, wherein, Figure 2 (a) is a schematic diagram of a stacked two-dimensional intracardiac ultrasound transducer array in planar form; Figure 2 (b) is a lateral view of the transducer array stack along the width and height directions; Figure 3 This is a schematic diagram of the grouping and sub-aperture division of a planar two-dimensional intracardiac ultrasound transducer array. According to the grouping scheme of the ultrasound transducer array, the two-dimensionally distributed array elements are divided into multiple independent equivalent sub-apertures. Specifically, the size of the equivalent sub-apertures is set, and the equivalent sub-apertures are formed by grouping multiple spatially adjacent array elements of the two-dimensional transducer array, such as... Figure 3 In (a), spatially adjacent array elements of the same color constitute an equivalent sub-aperture, and traversing the complete transducer array constitutes multiple independent equivalent sub-apertures. Further, the transducer grouping scheme can be one-dimensional or two-dimensional, and the number of grouped array elements along the length and height directions need not be equal. Specifically, the intracardiac ultrasound transducer array includes: an outer matching layer, an inner matching layer, a piezoelectric material layer, a dematching layer, a circuit layer, and a backing layer stacked sequentially from top to bottom. The inner matching layer, piezoelectric material layer, and dematching layer are partially cut to form gaps and electrical isolation, constituting independent array elements. Each array element is electrically connected to the circuit layer; A spatially adjacent independent array elements constitute a single equivalent sub-aperture.

[0035] In some embodiments, the size of the single equivalent sub-aperture is (M1, N1), and the A independent array elements are spatially adjacent array elements with length direction M1 and height direction N1; M1 and N1 are both positive integers.

[0036] In some embodiments, the single equivalent sub-aperture is at least 2, and the elements with the same serial number in all equivalent sub-apertures have the same static delay, for example, the first equivalent sub-aperture includes 4 elements with serial numbers 1, 2, 3, and 4, the second equivalent sub-aperture includes 4 elements with serial numbers 1, 2, 3, and 4, the third equivalent sub-aperture includes 4 elements with serial numbers 1, 2, 3, and 4, the elements with serial number 1 in the first, second, and third equivalent sub-apertures have the same static delay, the elements with serial number 2 in the first, second, and third equivalent sub-apertures have the same static delay, the elements with serial number 3 in the first, second, and third equivalent sub-apertures have the same static delay, and the elements with serial number 4 in the first, second, and third equivalent sub-apertures have the same static delay. The elements in any equivalent sub-aperture have the same dynamic delay.

[0037] In some embodiments, the number of single equivalent sub-apertures is (M2, N2), and M2 and N2 are positive integers. For example, M1, M2, N1, and N2 have no size relationship and are positive integers. For example, the total number of elements of the transducer array is 10*10=100. The equivalent sub-aperture size M1=5 and N1=5, so the total number of M2=2 and N2=2, i.e., M2*N2=4 sub-apertures.

[0038] In some embodiments, the A independent elements are two-dimensionally distributed along the length direction and the height direction of the transducer array, and the number of elements divided along the length and height directions is equal or unequal; A is a natural number greater than 0.

[0039] Optionally, the length and width of a single element are the same or different.

[0040] In some embodiments, the circuit layer includes a flexible circuit layer and an application-specific integrated circuit layer stacked in sequence from top to bottom, and a de-matching layer is interposed between the piezoelectric material layer and the flexible circuit layer to absorb or scatter the backward acoustic wave of the piezoelectric material layer and connect the piezoelectric material layer and the flexible circuit layer.

[0041] In some embodiments, the ground and input / output circuits in the flexible circuit layer are arranged at both ends of the length direction of the ultrasonic transducer array.

[0042] Optionally, the middle of the flexible circuit layer is provided with a switching board in a two-dimensional array, and the switching board connects the application-specific integrated circuit pad and the ultrasonic transducer element.

[0043] In some embodiments, the application specific integrated circuit layer comprises excitation pulse circuit, transmitting circuit, receiving circuit and analog front-end circuit, the excitation pulse circuit generates an electric pulse signal, the electric pulse signal is transmitted to the transmitting circuit for amplification and modulation; the amplified and modulated electric pulse signal drives the ultrasonic transducer array to transmit ultrasonic waves, the ultrasonic waves are captured by the transducer array and converted into electric signals (the ultrasonic waves are captured by the transducer array and converted into electric signals after being reflected from the target); the receiving circuit receives and processes (amplifies and pre-processes) the electric signals and transmits them to the analog front-end circuit for phase and amplitude regulation.

[0044] Optionally, the excitation pulse circuit comprises B-mode high-voltage pulse and Doppler-mode low-voltage pulse circuit.

[0045] Optionally, the receiving circuit comprises pre-signal amplification circuit, gain compensation circuit and delay circuit, the signals of the transmitting circuit and the receiving circuit are connected to the bottom of the piezoelectric material layer through the solder pad of the flexible circuit layer and the de-matching layer; when the transducer transmitting circuit works, the receiving circuit remains in the closed state; after the transmission is completed, the receiving circuit works to receive the ultrasonic echo and convert it into an analog electric signal.

[0046] In some embodiments, the analog front-end circuit comprises a sub-aperture processor, which applies a separate static time delay to the received signals of all elements in a sub-aperture, adds the received signals to form a virtual element and realizes deflection in a specific direction.

[0047] In some embodiments, the application specific integrated circuit comprises circuit systems with the same number of elements, which are connected to the elements one by one through the solder pad; the size of the application specific integrated circuit corresponding to each element does not exceed the size of the element.

[0048] In some embodiments, the outer surface of the piezoelectric material layer is connected to the ground electrode through the conductive inner matching layer.

[0049] In some embodiments, the outer matching layer and the inner matching layer are used to couple the piezoelectric material layer and the biological tissue.

[0050] Optionally, the de-matching layer is used to decouple the piezoelectric material layer and the flexible circuit and the silicon-based application specific integrated circuit, so as to simplify the thickness of the piezoelectric material and make it work under the quarter-wave mode.

[0051] Embodiment 1

[0052] As Figure 1 , 2 is a schematic diagram of the geometry of a two-dimensional intracardiac ultrasonic transducer array stack in a planar form, which specifically comprises the stacking of the outer matching layer, the inner matching layer, the piezoelectric material layer, the de-matching layer, the flexible circuit layer, the application specific integrated circuit layer and the backing layer from top to bottom. Figure 3Schematic diagram of the grouping and sub-aperture division of the planar form two-dimensional intracardiac ultrasound transducer array. According to the grouping scheme of the ultrasound transducer array, the elements obtained by cutting are divided into multiple independent equivalent sub-apertures in a two-dimensional distribution. Specifically, the size of the equivalent sub-aperture is set, and the equivalent sub-aperture is formed by grouping multiple spatially adjacent elements of the two-dimensional transducer array, such as Figure 3 In (a), spatially adjacent elements of the same color constitute an equivalent sub-aperture, and multiple independent equivalent sub-apertures are formed by traversing the entire transducer array. Further, the transducer grouping scheme can be one-dimensional or two-dimensional, and the number of grouped elements in the length direction and the height direction does not have to be equal. Specifically, the inner matching layer, the piezoelectric material, and the de-matching layer form independent and regularly arranged transducer elements by cutting to form gaps and electrical isolation. Each element is electrically connected through the ground layer and the flexible circuit; the outer surface of the piezoelectric material is connected to the ground electrode through the conductive inner matching layer; the de-matching layer of high acoustic impedance is interposed between the piezoelectric material and the flexible circuit, which absorbs or scatters the backward acoustic waves of the piezoelectric material and connects the piezoelectric material and the flexible circuit; the application-specific integrated circuit contains transmission, reception and signal processing circuits, and the circuit connects the piezoelectric material through the pads of the flexible circuit, the de-matching layer, and transmits and receives electrical signals.

[0053] Further, the matching layer is usually composed of multiple layers, including but not limited to the outer matching layer and the inner matching layer. The outer matching layer is generally made of materials with low acoustic impedance, such as epoxy resin or polyurethane, etc.; the inner matching layer is made of materials with high acoustic impedance, such as aluminum oxide ceramic or titanium alloy, etc. The thickness of the matching layer is usually one-quarter wavelength or its odd multiples to achieve the best acoustic energy transmission effect. The design goal of the matching layer is to gradually transition the acoustic impedance, thereby reducing the acoustic impedance mismatch between the transducer and the detection medium and improving the transmission efficiency of acoustic energy.

[0054] Further, the piezoelectric material is the core component of the ultrasonic transducer, and commonly used materials include piezoelectric ceramics, piezoelectric single crystals, and piezoelectric composites, etc. The selection of piezoelectric material depends on the application scenario and performance requirements of the transducer, such as frequency range, bandwidth, sensitivity, etc. The thickness of the piezoelectric material layer is usually half a wavelength to obtain the best resonance effect. On both main surfaces of the piezoelectric material, a conductive material (such as gold, silver or platinum) is coated as an electrode for applying excitation voltage or collecting electrical signals.

[0055] Further, the de-matching layer (or called sound isolation layer) is usually located on the back of the piezoelectric material, which is used to absorb or scatter the backward propagating acoustic waves to prevent them from reflecting back to the piezoelectric material and affecting the performance of the transducer. The de-matching layer can adopt various materials and structures, such as polymer-based composite materials, porous materials or gradient structure materials, etc. The design goal of the de-matching layer is to maximize the reduction of acoustic energy in the backward direction while ensuring the structural strength, thereby improving the bandwidth and sensitivity of the transducer.

[0056] Further, flexible circuits are mainly used in ultrasonic transducers to realize the transmission and processing of electrical signals. Flexible printed circuit boards (FPC) can be bent according to the geometry of the transducer to adapt to different spatial layout requirements. Application-specific integrated circuits can integrate signal amplification, filtering, analog-to-digital conversion and other functions to improve the efficiency and accuracy of signal processing. Reasonable design of flexible circuits and application-specific integrated circuits can significantly reduce electromagnetic interference, improve signal-to-noise ratio, and simplify the overall structure of the transducer.

[0057] Further, the backing material in the ultrasonic transducer plays a supporting and sound-absorbing role. Common backing materials include epoxy resin, polyurethane and various composite materials. The acoustic impedance and attenuation coefficient of the backing have a significant impact on the performance of the transducer. The ideal backing material should have a high acoustic attenuation coefficient and appropriate acoustic impedance to effectively absorb and scatter back sound waves. The thickness and shape of the backing need to be optimized according to the working frequency and application requirements of the transducer to achieve the best bandwidth and sensitivity.

[0058] Further, the design of the ultrasonic transducer should consider factors such as working frequency, bandwidth, sensitivity, acoustic beam characteristics, geometric size, etc. The geometric shape of the transducer (such as concave, flat or convex) also affects its focusing characteristics and sound field distribution. The appropriate transducer can be designed according to the working environment, application scenario and cost of the transducer, such as the curved structure and the transducer with holes.

[0059] The transducer array is formed by cutting the transducer material stack into a two-dimensional array. Specifically, according to the geometric parameters of the transducer array such as the outer diameter, length, height, element size and element gap, the voids and electrical partitions formed by cutting the inner matching layer, piezoelectric material and de-matching layer are distributed two-dimensionally along the length and height directions of the transducer array, and the formed transducer elements are arranged two-dimensionally.

[0060] Further, the element size includes the length and width of the element, which can be inconsistent, and the number of elements divided along the length and height directions does not have to be equal.

[0061] According to the grouping scheme of the ultrasonic transducer array, the two-dimensionally distributed elements obtained by cutting are divided into multiple independent equivalent sub-apertures. Specifically, the size of the equivalent sub-aperture is set, and the equivalent sub-aperture is formed by grouping multiple spatially adjacent elements of the two-dimensional transducer array, and multiple independent equivalent sub-apertures are formed by traversing the entire transducer array.

[0062] Further, the transducer grouping scheme can be one-dimensional or two-dimensional, and the number of grouped elements along the length and height directions does not have to be equal. The basis of the grouping scheme is the diameter of the catheter, the spatial size of the flexible circuit board and the application-specific integrated circuit;

[0063] The upper and lower surfaces of the transducer piezoelectric material are respectively coupled to two front matching layers and one back matching layer. Specifically, the two front matching layers are used to couple the piezoelectric material to the biological tissue; the back matching layer with high impedance is used to decouple the piezoelectric material from the flexible circuit and the silicon-based application-specific integrated circuit, so as to simplify the thickness of the piezoelectric material and make it work in the quarter-wave mode.

[0064] All the ground and input / output circuits in the transducer flexible circuit are arranged at both ends of the length direction of the ultrasonic transducer array. Specifically, the signals of the transmitting and receiving circuits in the application-specific integrated circuit are connected to the bottom of the piezoelectric material through the pads of the flexible circuit and the back matching layer; the ground connection is connected to the outer surface of the piezoelectric material through the conductive inner matching layer; the middle part of the flexible circuit is a switching board of the two-dimensional array, which is used to provide the connection between the pads of the application-specific integrated circuit and the elements of the ultrasonic transducer array.

[0065] The transducer application-specific integrated circuit contains the same number of circuit systems as the number of elements of the ultrasonic transducer array. Specifically, each circuit system is connected to an element of the ultrasonic transducer array through a solder joint; the size of the application-specific integrated circuit corresponding to each element should not be larger than the size of the element.

[0066] Further, the application-specific integrated circuit contains an excitation pulse circuit, a transmitting circuit, a receiving circuit and an analog front-end circuit. Specifically, the transmitting pulse circuit contains a B-mode high-voltage pulse and a Doppler-mode low-voltage pulse circuit; each element corresponding circuit system uses a single unipolar pulser, while the transmitting time delay state of the element is limited to simplify the transmitting circuit and realize a smaller circuit volume; the receiving circuit contains a pre-amplifier circuit, a gain compensation circuit and a delay circuit, which remains in a closed state when the transducer transmitting circuit is working; after the transmitting is completed, the receiving circuit works to receive the ultrasonic echo and convert it into an analog electrical signal.

[0067] The transducer array analog front-end circuit contains a sub-aperture processor. Specifically, according to the division of the sub-aperture, a separate static time delay is applied to the receiving signals of all the elements in the sub-aperture, then these signals are added to form a larger virtual element, and deflection is realized in a specific direction.

[0068] Further, after the echo signals of the analog front-ends of all the sub-apertures are digitized, delayed and combined, the beam forming is performed in the system back-end, and the final ultrasonic image is obtained. Specifically, the echo signals of the elements in each sub-aperture are delayed, superimposed to obtain an analog echo signal representing a virtual element, and are digitized and sampled; the sampled digital echo signals are transmitted to the system back-end through the flexible cable; the dynamic digital time delay necessary for dynamic focusing is applied to the digital echo signals transmitted back by all the sub-apertures and is superimposed to construct the ultrasonic image of the transducer scanning space.

[0069] Embodiment 2

[0070] This embodiment is based on an intracardiac ultrasound transducer array of the present disclosure, and illustrates the implementation process of its electronic scanning, focusing and imaging. As shown in Figure 1 is a side view of a planar ultrasound transducer, which is packaged in the distal part of a small-diameter intracardiac catheter, and each array element can independently transmit and receive ultrasound signals. The transducer array is arranged in a two-dimensional matrix to achieve large-angle and three-dimensional spatial imaging in the narrow space of the catheter.

[0071] In the implementation process, first, the intracardiac ultrasound transducer array is sent an excitation signal by an external control system, which causes the piezoelectric material of the array element to produce mechanical vibration by applying a specific drive voltage to the transducer array element, and then radiates ultrasound waves outward through the inner matching layer and the outer matching layer.

[0072] As shown in Figure 4 is a schematic diagram of the echo reception and imaging processing process of the transducer array. The transmitted ultrasound waves form ultrasound echoes through reflection and scattering when passing through the heart tissue. The ultrasound echoes are received by the transducer array element and converted into electrical signals over time through the inverse piezoelectric effect. As shown in Figure 4 (a), in the analog front-end circuit of each sub-aperture, the electrical signals generated by each array element are superimposed to form an analog echo signal representing a virtual array element after preamplification, time delay circuit and summation circuit.

[0073] Next, the signals after the analog front-end enter the system back-end, as shown in Figure 4 (b). Each analog signal is converted into a digital signal by an analog-to-digital converter. Then, according to the positions of the corresponding array element and the imaging focal point, the dynamic focusing time delay is calculated for each depth, and the time delay is applied to the digital echo signal to achieve in-phase of each signal. Finally, after digital beamforming and other ultrasound image processing, the final output ultrasound image is obtained.

[0074] It should be noted that the above basic processes of transmission, reception and imaging can be used for common imaging methods such as phased array scanning imaging and planar wave scanning imaging.

[0075] Compared with conventional two-dimensional transducer arrays, the ultrasound transducer array design of the present embodiment can significantly reduce the number of cable connections and the volume of circuit. In addition, since the present embodiment adopts the signal processing and imaging process of the analog front-end and the system back-end, it can further simplify the circuit structure while achieving large-angle three-dimensional spatial scanning and obtaining high-resolution and high-frame-rate ultrasound volume imaging.

[0076] It is worth mentioning that only the intracardiac ultrasound transducer array based on the micro beamformer and the design method are listed here; the application of the above array and design method is not limited to the intravascular, transesophageal and other micro ultrasound transducer array / catheter.

[0077] The following points need to be explained:

[0078] (1) The drawings of the embodiments of the present disclosure only relate to the structures involved in the embodiments of the present disclosure, and other structures can be referred to the general design.

[0079] (2) In the case of no conflict, the embodiments of the present disclosure and the features in the embodiments can be combined with each other to obtain new embodiments.

[0080] The above is only a specific implementation of the present disclosure, but the protection scope of the present disclosure is not limited thereto, and the protection scope of the present disclosure should be subject to the protection scope of the claims.

[0081] The above description of the embodiments is only for the understanding of the present utility model. It should be pointed out that for ordinary skilled persons in the art, without departing from the principles of the present utility model, the present utility model can be improved in several ways, and these improvements will also fall within the protection scope of the claims of the present utility model.

Claims

1. An intracardiac ultrasound transducer array, comprising: The array comprises: from top to bottom, an outer matching layer, an inner matching layer, a piezoelectric material layer, a de-matching layer, a circuit layer and a backing layer, the inner matching layer, the piezoelectric material layer and the de-matching layer are partially cut to form gaps and electrical partitions, thereby forming independent elements, each element is in electrical communication with the circuit layer; A plurality of adjacent elements form a single equivalent sub-aperture.

2. The intracardiac ultrasound transducer array of claim 1, wherein, The size of the single equivalent sub-aperture is (M1, N1), and the A independent elements are adjacent in space and have M1 elements in the length direction and N1 elements in the height direction; M1 and N1 are positive integers.

3. The intracardiac ultrasound transducer array of claim 1, wherein, The number of single equivalent sub-apertures is at least 2, and the elements with the same serial number in all equivalent sub-apertures have the same static time delay; each element in any equivalent sub-aperture has the same dynamic time delay.

4. The intracardiac ultrasound transducer array of claim 1, wherein, The number of single equivalent sub-apertures is (M2, N2), and M2 and N2 are positive integers.

5. The intracardiac ultrasound transducer array of claim 1, wherein, The A independent elements are two-dimensionally distributed along the length direction and the height direction of the transducer array, and the number of elements divided along the length and the height is equal or unequal; The length and the width of a single element are equal or unequal.

6. The intracardiac ultrasound transducer array of claim 1, wherein, The circuit layer comprises a flexible circuit layer and an application-specific integrated circuit layer stacked from top to bottom, and the de-matching layer is arranged between the piezoelectric material layer and the flexible circuit layer, thereby absorbing or scattering the backward acoustic wave of the piezoelectric material layer and connecting the piezoelectric material layer and the flexible circuit layer.

7. The intracardiac ultrasound transducer array of claim 6, wherein, The ground and input / output circuits in the flexible circuit layer are arranged at both ends of the length direction of the ultrasonic transducer array; The middle of the flexible circuit layer is provided with a two-dimensional array of adapter boards, and the adapter boards connect the application-specific integrated circuit pads and the ultrasonic transducer elements.

8. The intracardiac ultrasound transducer array of claim 6, wherein, The application-specific integrated circuit layer comprises an excitation pulse circuit, a transmitting circuit, a receiving circuit and an analog front-end circuit, the excitation pulse circuit generates an electric pulse signal, the electric pulse signal is transmitted to the transmitting circuit for amplification and modulation; the amplified and modulated electric pulse signal drives the ultrasonic transducer array to emit ultrasonic waves, the ultrasonic waves are captured by the transducer array and converted into electric signals; the receiving circuit receives and processes the electric signals and transmits them into the analog front-end circuit for phase and amplitude control. The receiving circuit comprises a pre-signal amplification circuit, a gain compensation circuit and a delay circuit. The analog front-end circuit comprises a sub-aperture processor, the sub-aperture processor applies a separate static time delay to the received signals of all elements in a sub-aperture, adds the received signals to form a virtual element and realizes deflection in the direction.

9. The intracardiac ultrasound transducer array of claim 6, wherein, The application-specific integrated circuit comprises a number of circuit systems equal to the number of elements, and the circuit systems are connected to the elements one by one through solder joints; the size of the application-specific integrated circuit corresponding to each element is not greater than the size of the element.

10. The intracardiac ultrasound transducer array of any of claims 1-9, wherein, The outer matching layer and the inner matching layer are used to couple the piezoelectric material layer and the biological tissue; The de-matching layer is used to decouple the piezoelectric material layer from the flexible circuit and the silicon-based application-specific integrated circuit, thereby simplifying the thickness of the piezoelectric material and enabling it to work under a quarter-wave mode.

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