Double-frequency intravascular ultrasonic catheter and ultrasonic imaging system

Abstract

The invention relates to a double-frequency intravascular ultrasonic catheter and an ultrasonic imaging system.The catheter comprises a double-frequency probe, a catheter tip, an ultrasonic probe, a developing marker, a connector and a sliding ring, the double-frequency probe is arranged in the catheter, the ultrasonic probe is composed of an ultrasonic transducer and an ultrasonic transducer backing layer and used for transmitting and receiving ultrasonic signals, and the developing marker is arranged on the developing marker; the connector is used for connecting the catheter to an imaging system of the dual-frequency intravascular ultrasound catheter, the dual-frequency intravascular ultrasound imaging system comprises a first function generator, a second function generator, a low-frequency pulse generator / receiver, a high-frequency pulse generator / receiver and an image processing instrument, low-frequency and high-frequency signals can be used at the same time, and the multi-frequency imaging capability is achieved.

Description

Technical Field

[0001] The present application belongs to the field of medical devices, and specifically relates to a dual-frequency intravascular ultrasound catheter and an ultrasound imaging system. Background Art

[0002] Tumor interventional therapy is a method of treating tumors through local treatment methods such as catheters and intravascular operations. Interventional therapy includes transcatheter interventional vascular therapy, tumor ablation, embolization therapy, etc. Intravascular ultrasound imaging technology (IVUS) uses a special catheter with an ultrasonic transducer connected to the end for medical imaging technology, which can provide real-time images and positioning information, display the wall of the lesion, and improve the accuracy of diagnosis. Traditional intravascular ultrasound catheters are generally mechanical catheters with single-element transducers and electronic phased array catheters with linear array transducers. The higher the transducer frequency in the intravascular ultrasound catheter, the better the resolution of the ultrasound image. The transducer frequency of traditional electronic phased array catheters is generally around 20MHz, and the transducer frequency of mechanical catheters is generally around 40MHz. The frequencies are relatively low, and it is impossible to accurately detect tiny tissue lesions and early atherosclerotic plaques on the vascular wall. By combining dual-frequency intravascular ultrasound catheters, tumor interventional therapy can be more accurate and real-time, and more comprehensive monitoring can be performed during the treatment process to improve the safety and effectiveness of treatment. Summary of the invention

[0003] The present application provides a dual-frequency intravascular ultrasound catheter and imaging system for coronary artery imaging, which provides complementary images of deep and shallow features of the vascular wall. The high-frequency function significantly improves the resolution, solving the problem of insufficient spatial resolution of traditional intravascular ultrasound imaging.

[0004] A dual-frequency intravascular ultrasound catheter, comprising:

[0005] A dual-frequency probe is disposed inside the catheter and directly contacts the wall of the blood vessel to be imaged;

[0006] The catheter tip is arranged at the distal end of the catheter and is tapered;

[0007] An ultrasonic probe, composed of an ultrasonic transducer and an ultrasonic transducer backing layer, for transmitting and receiving ultrasonic signals;

[0008] As well as housings, visible and invisible markers, connectors and slip rings.

[0009] The above-mentioned catheter is also provided with visible and invisible markers for determining the position and direction of the catheter. The proximal end of the catheter is also provided with a connector for connecting the catheter to the imaging system of the dual-frequency intravascular ultrasound catheter. The slip ring is arranged on the connector to allow the rotating part of the catheter to rotate around the axis of the catheter without affecting its external cables and connecting lines.

[0010] According to one embodiment of the present application, the size of the ultrasonic transducer is set to 0.5mm*0.5mm, and the thickness is set to 0.3mm.

[0011] According to one embodiment of the present application, the material of the ultrasonic transducer is piezoelectric material.

[0012] According to one embodiment of the present application, the alignment of the ultrasonic transducer is set to a front-to-back configuration.

[0013] According to one embodiment of the present application, the alignment of the ultrasonic transducer is set to a left-right configuration.

[0014] According to one embodiment of the present application, the alignment of the ultrasonic transducers can also be set to a back-to-back configuration.

[0015] The present application also provides a dual-frequency intravascular ultrasound imaging system, which includes a first function generator, a second function generator, a low-frequency pulse generator / receiver, a high-frequency pulse generator / receiver, an image processing instrument, and the dual-frequency intravascular ultrasound catheter described in any of the above embodiments, wherein:

[0016] The first function generator is used to generate a low-frequency ultrasonic signal;

[0017] The second function generator is used to generate a high-frequency ultrasonic signal;

[0018] The image processing instrument is used to combine and process the low-frequency ultrasonic signal and the high-frequency ultrasonic signal to generate an image;

[0019] The dual-frequency intravascular ultrasound imaging system performs data processing to correct the position and direction of the catheter;

[0020] According to one embodiment of the present application, the ultrasonic imaging system can use low-frequency and high-frequency signals simultaneously and has multi-frequency imaging capabilities.

[0021] The beneficial effect of the present application is that the dual-frequency intravascular ultrasound catheter and ultrasound imaging system provided by the present application can use low-frequency and high-frequency signals simultaneously to obtain multi-level, detailed and high-quality images of the blood vessels. This helps doctors to understand the condition more comprehensively and provide more accurate diagnosis and treatment for patients. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments are briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative work, among which:

[0023] Figure 1 It is a schematic diagram of the interaction of components of a dual-frequency intravascular ultrasound catheter of the present application;

[0024] Figure 2 It is a schematic diagram of an alignment method of an ultrasonic transducer in an ultrasonic probe of a dual-frequency intravascular ultrasonic catheter of the present application;

[0025] Figure 3 It is a diagram of an imaging system of a dual-frequency intravascular ultrasound catheter of the present application;

[0026] in:

[0027] 100. catheter; 110. dual-frequency probe; 120. catheter tip; 130. ultrasound probe; 131. ultrasound transducer; 132. ultrasound transducer backing layer; 140. sheath; 150. visible and invisible marker; 160. connector; 200. slip ring. DETAILED DESCRIPTION

[0028] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below in conjunction with the accompanying drawings. It is to be understood that the specific embodiments described herein are only used to explain the present application, rather than to limit the present application. It should also be noted that, for ease of description, only some structures related to the present application are shown in the accompanying drawings, rather than all structures. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0029] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0030] In this application, unless otherwise clearly specified and limited, if the terms "installed", "connected", "connected", "fixed" and the like appear, these terms should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integrated connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0031] See also Figure 1 and Figure 2An embodiment of the present application provides a dual-frequency intravascular ultrasound catheter 100, including a dual-frequency probe 110, a catheter tip 120, an ultrasound probe 130, a sheath 140, a visible and invisible marker 150, a connector 160, and a slip ring 200.

[0032] The catheter tip 120 is arranged at the distal end of the catheter 100, and is specifically conical, which helps the catheter 100 to pass through the narrow or curved part of the blood vessel, and is easier to guide the catheter 100 into the vascular system to reduce damage to the inner wall of the blood vessel. The dual-frequency probe 110 is arranged inside the catheter, directly in contact with the wall of the blood vessel to be imaged, and can fuse ultrasonic signals of different frequencies. At the same time, it can be used to collect ultrasonic signals reflected in the patient's body, provide more comprehensive and detailed images of the blood vessels, and identify the pathological structure. The ultrasonic probe 130 is arranged at a position close to the catheter tip 120 to ensure that it is as close as possible to the blood vessel area to be imaged. The ultrasonic probe 130 is composed of an ultrasonic transducer 131 and an ultrasonic transducer backing layer 132, which is used to transmit and receive ultrasonic signals. The ultrasonic transducer backing layer 132 supports the structure of the ultrasonic probe 130 and reduces ultrasonic reflection to prevent the generation of callback, improves the propagation path of ultrasonic waves, and is used to obtain high-resolution images of the internal tissues of the blood vessels, which is convenient for diagnosis and treatment navigation. The design of the sheath 140 enables the catheter 100 to have good tactile feedback and visibility. The catheter 100 is also provided with a visible and invisible marker 150, which is clearly visible in the ultrasound image and can help the doctor determine the position and direction of the catheter 100. The proximal end of the catheter 100 is provided with a connector 160 for connecting the catheter to the imaging system of the dual-frequency intravascular ultrasound catheter so that the doctor can observe and record the ultrasound image. The slip ring 200 is provided on the connector 160, allowing the rotating part of the catheter 100 to rotate around the axis of the catheter 100 without affecting its external cables and connecting wires, and is used to maintain the flexibility of the catheter 100, which helps the catheter 100 maintain flexibility when passing through a curved position in the vascular system. The slip ring 200 can ensure that electrical signals and data can be smoothly transmitted from the rotating part to the fixed part of the catheter 100 to achieve effective data transmission and obtain images and real-time information.

[0033] In order to better convert the electrical signal into ultrasonic waves, after being reflected from the human body, it is converted back into electrical signals and sent back to the system to form an image. The present application selects two independent ultrasonic transducers 131, and adopts a stack configuration to achieve dual-frequency performance. The ultrasonic transducer backing layer 132 is set to a shape similar to a rectangular prism, and the axial dimension is limited to 0.6mm*0.6mm. The sheath wall thickness is set to 0.1mm, so as to better transport the catheter 100 to the target position, and at the same time ensure that the ultrasonic transducer 131 will not hit the inner wall of the catheter 100 during the rotation process.

[0034] See also Figure 2(a) The alignment of the two ultrasonic transducers 131 of the present application on the ultrasonic transducer backing layer 132 is a front-to-back configuration alignment, which increases the rigid length, resulting in reduced flexibility of the catheter 100 when passing through a curved or sharp turn of the cardiovascular system, which will impose certain restrictions on the maneuverability of the catheter 100. In addition, image registration must be performed through pull-back scanning, which means that the ultrasonic probe 130 needs to be pulled back during scanning to ensure that the data of the two imaging sources configured front and back can be registered and merged into one image. The advantage of this front-to-back configuration is that it ensures that the size of the ultrasonic transducer 131 is compatible with the outer diameter of the catheter 100, and the two ultrasonic transducers 131 can be optimized independently.

[0035] See also Figure 2 (b), the alignment of the two ultrasonic transducers 131 can also be a left-right configuration, emitting ultrasonic waves from the same horizontal plane to obtain cross-sectional images. This registration process allows the information of the two to be merged to generate a more comprehensive and accurate image, providing more anatomical information and details. However, this left-right configuration of ultrasonic transducers 131 will increase the outer diameter of the catheter 100 by two times. This is because it is necessary to place two ultrasonic transducers 131 and related hardware in the transverse direction, thereby increasing the overall transverse size of the catheter 100. Therefore, when designing this configuration, it is necessary to balance the image quality and the physical properties of the catheter 100 to ensure that while providing high-quality images, the outer diameter of the catheter 100 is not excessively increased so that it can be effectively used in clinical applications. The component materials and thicknesses of the two ultrasonic transducers 131 can be flexibly selected during the process.

[0036] It should be noted that the ultrasonic transducer 131 of the present application adopts Figure 2 (c) Alignment: back-to-back configuration, aligned in the thickness direction, most effectively utilizing the internal space of the cylindrical shell of the catheter 100, providing a smaller outer diameter and a shorter front rigid length, the two ultrasonic transducers 131 generate images in the same cross-section, and real-time image registration of the two frequencies can be completed by rotating one of the images 180 degrees. The two coplanar images generated when the catheter 100 is rotated and scanned can complement each other.

[0037] In the specific setting, the material of the ultrasonic transducer 131 can be specifically piezoelectric ceramics, piezoelectric polymers and ferroelectric single crystals. Since the dielectric constant and the surface area of ​​the piezoelectric material jointly determine the electrical impedance of the ultrasonic transducer 131, the influence caused by the dielectric constant should be considered when selecting the material. Specifically, PMN-PT crystal is selected. The single crystal has excellent piezoelectric properties, nonlinear optical properties and pyroelectric properties to meet the application and be made into a new generation of high-performance piezoelectric transducers. In order to manufacture a transducer with a center frequency exceeding 100MHz, a material with a lower dielectric constant is required. This application uses lithium niobate material, which is suitable for sensor elements of large aperture and high-frequency units.

[0038] For further information, see Figure 3 , is a diagram of a dual-frequency intravascular ultrasound imaging system. The first function generator generates a low-frequency ultrasonic signal for deep imaging, observing deep structures and blood flow, and penetrating tissues to obtain deeper image information. The second function generator generates a high-frequency pulse ultrasonic signal for providing higher-resolution images and more delicate anatomical structures to provide more comprehensive information. The high-frequency pulse receiver receives the high-frequency pulse ultrasonic signal, and the low-frequency pulse receiver receives the low-frequency pulse ultrasonic signal. Through the Labview GUI graphical user interface and DAQ data acquisition, the high-frequency and low-frequency pulse ultrasonic signal data are combined to perform image processing to generate high-resolution, deep information-rich intravascular images. The processed data passes through the motion stage to correct the position and direction of the catheter 100. The slip ring 200 connects the dual-frequency probe 110 with the high-frequency and low-frequency pulse generator / receiver, sends the high-frequency and low-frequency signals into the patient's body through the dual-frequency probe 110, and receives the reflected signal to ensure two-way signal transmission. The dual-frequency probe 110 enters the patient's vascular system and scans inside the blood vessels. The system simultaneously generates high-frequency and low-frequency pulse ultrasonic waves to make the image details richer.

[0039] The above description is only an implementation method of the present application, and does not limit the patent scope of the present application. Any equivalent structure or equivalent process transformation made using the contents of the present application specification and drawings, or directly or indirectly used in other related technical fields, are also included in the patent protection scope of the present application.

Claims

1. A dual-frequency intravascular ultrasound catheter, characterized in that: The catheter comprises: A dual-frequency probe is disposed inside the catheter and directly contacts the wall of the blood vessel to be imaged; The catheter tip is arranged at the distal end of the catheter and is tapered; An ultrasonic probe, composed of an ultrasonic transducer and an ultrasonic transducer backing layer, for transmitting and receiving ultrasonic signals, wherein the ultrasonic transducer is aligned in a back-to-back configuration; As well as housings, visible and invisible markers, connectors and slip rings.

2. The dual-frequency intravascular ultrasound catheter according to claim 1, characterized in that: The visible and invisible marker is arranged on the outer surface of the catheter and is used to determine the position and direction of the catheter.

3. The dual-frequency intravascular ultrasound catheter according to claim 1, characterized in that: The connector is used to connect the catheter to an imaging system of a dual-frequency intravascular ultrasound catheter.

4. The dual-frequency intravascular ultrasound catheter according to claim 3, characterized in that: The slip ring is arranged on the connector, allowing the catheter rotating part to rotate around the catheter axis without affecting its external cables and connecting lines.

5. The dual-frequency intravascular ultrasound catheter according to claim 1, characterized in that: The size of the ultrasonic transducer is set to 0.5mm*0.5mm, and the thickness is set to 0.3mm.

6. The dual-frequency intravascular ultrasound catheter according to claim 1, characterized in that: The material of the ultrasonic transducer is piezoelectric material.

7. The dual-frequency intravascular ultrasound catheter according to claim 3, characterized in that: The alignment of the ultrasonic transducer may also be arranged in a front-to-back configuration.

8. The dual-frequency intravascular ultrasound catheter according to claim 1, characterized in that: The alignment of the ultrasonic transducer is arranged in a left-right configuration.

9. A dual-frequency intravascular ultrasound imaging system for real-time imaging and evaluation of the internal structure of a blood vessel, characterized in that: The dual-frequency intravascular ultrasound imaging system comprises a first function generator, a second function generator, a low-frequency pulse generator / receiver, a high-frequency pulse generator / receiver, an image processing instrument, and a dual-frequency intravascular ultrasound catheter as claimed in any one of claims 1 to 8, wherein: The first function generator is used to generate a low-frequency ultrasonic signal; The second function generator is used to generate a high-frequency ultrasonic signal; The image processing instrument is used to combine and process the low-frequency ultrasonic signal and the high-frequency ultrasonic signal to generate an image; The dual-frequency intravascular ultrasound imaging system performs data processing to correct the position and direction of the catheter.

10. The dual-frequency intravascular ultrasound imaging system according to claim 9, characterized in that: The ultrasonic imaging system can use low-frequency and high-frequency signals simultaneously and has multi-frequency imaging capability.

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