Method for manufacturing an ultrasonic catheter, ultrasonic catheter and forming mold therefor

Abstract

The application discloses a manufacturing method of an ultrasonic catheter, the ultrasonic catheter and a forming die thereof. The manufacturing method of the ultrasonic catheter comprises the following steps: preparing an array stack; selecting a lead-out wire; coating a polymer material at a preset distance from one end of the lead-out wire to form a preformed tube; electrically connecting one end of the lead-out wire close to the preformed tube to the array stack; adopting split pouring to manufacture a sound-transparent protective layer coated on the periphery of the array stack and one end of the preformed tube close to the array stack; electrically connecting the other end of the lead-out wire away from the preformed tube to a circuit connector; and forming a Parylene coating layer on the outer surface of the sound-transparent protective layer. The Parylene coating layer enables the sound-transparent protective layer to better adapt to the vascular environment of the human body and meet the requirements for use in blood vessels. Therefore, the selection range of the manufacturing material of the sound-transparent protective layer is wider, and a material with a lower pouring temperature can be selected to manufacture the sound-transparent protective layer, so that the array stack is prevented from being separated due to heat, and the acoustic performance, consistency and qualification rate of the ultrasonic catheter are improved.

Description

Technical Field

[0001] This invention relates to the field of ultrasonic catheter manufacturing technology, and more particularly to a method for manufacturing an ultrasonic catheter, an ultrasonic catheter and its molding die. Background Technology

[0002] Ultrasonic catheters are used to push their ultrasonic transducers through the vascular cavity to the detection site (coronary artery or heart chamber), offering the advantage of higher imaging resolution compared to transducers used for external imaging. Due to the limitations of the vascular lumen size, ultrasonic catheters are typically less than 3 mm in diameter. Taking an intracardiac ultrasonic catheter as an example, the ultrasonic transducer on the catheter consists of a sound-absorbing layer, lead wires, a circuit board, piezoelectric material, and a matching layer, and is covered with a sound-transmitting protective layer. Currently, the sound-transmitting protective layer is often made of block polyetheramide resin, commonly known commercially as Pebax, which offers advantages such as low attenuation of sound signal intensity and easy connection to the sheath.

[0003] There are generally two methods for manufacturing this protective layer. One method is to first pre-form the Pebax material, and then use UV adhesive to bond the Pebax to the matching layer, taking advantage of the transparency of the Pebax material, to form a protective layer. If pigments are added to the Pebax material, epoxy adhesive or quick-drying adhesive is used to bond the ultrasonic transducer to the Pebax. The other method is to melt the Pebax at a high temperature (usually above 200°C) and then wrap it around the ultrasonic transducer.

[0004] For the first production method, please refer to Figure 1 and Figure 2 Since the protective layer is a cylindrical structure with one end closed, when using UV glue or epoxy glue to bond Pebax to the ultrasonic transducer, there is a problem that the thickness and uniformity of the glue layer are not easy to control. Once the thickness of the glue layer exceeds 10 micrometers, it will inevitably have an adverse effect on the acoustic performance and performance consistency of the transducer, such as sensitivity and bandwidth.

[0005] The second manufacturing method, which involves melting Pebax at temperatures above 200°C, causes the piezoelectric material to depolarize, meaning it loses its piezoelectric properties. The adhesive layers between the material layers also melt, causing the acoustic materials to separate and become unable to transmit or receive ultrasonic waves.

[0006] In addition, when the transducer is fitted with a cylindrical Pebax protective layer, because the speed of sound of Pebax (1520 m / s) is close to that of water, the transducer array elements are almost unable to focus on the short axis when emitting ultrasonic waves, resulting in a large slice thickness throughout the imaging depth and affecting the quality of the ultrasonic image.

[0007] Therefore, commercially available array-type ultrasound catheter products generally have poor acoustic performance and low imaging quality. How to improve the technical defects in the existing technology has always been a problem that ordinary technicians in this field urgently need to solve. Summary of the Invention

[0008] The purpose of this invention is to provide a method for manufacturing an ultrasonic catheter, an ultrasonic catheter and its molding mold, which can form a sound-transmitting protective tube at a lower casting temperature, thereby improving the acoustic performance, performance consistency and pass rate of the ultrasonic catheter. At the same time, it also provides a focusable sound-transmitting protective layer to improve the quality of ultrasonic imaging.

[0009] The technical solution provided by this invention is as follows:

[0010] A method for fabricating an ultrasonic catheter, comprising the following steps:

[0011] Prefabricated array stack;

[0012] Select the lead wire;

[0013] A pre-formed tube is made by covering a polymer material at a predetermined distance from one end of the lead wire.

[0014] Electrically connect the end of the lead wire closest to the preformed tube to the array stack;

[0015] A sound-permeable protective layer is created by using a split casting process to cover the outer periphery of the array stack and the preformed tube near the array stack.

[0016] Electrically connect the end of the lead wire away from the preformed tube to the line connector;

[0017] A Parylene coating is formed on the outer surface of the acoustic protective layer.

[0018] In some embodiments, the outer wall of the preformed tube is provided with a groove;

[0019] During the casting process, the groove allows the liquid material to flow in; the liquid material to be cast solidifies, and the groove is tightly bonded to the sound-permeable protective layer formed after solidification, so as to strengthen the connection strength between the preformed tube and the sound-permeable protective layer.

[0020] The liquid material is poured at room temperature and the curing temperature does not exceed 110℃.

[0021] In some embodiments, the prefabricated array stack includes the steps of:

[0022] The circuit board, sound-absorbing layer, piezoelectric material and matching layer are bonded together in a stacked manner;

[0023] Depending on the number of array elements, cut and bond the piezoelectric material and matching layer together, or, depending on the number of array elements, cut and bond the sound-absorbing layer, piezoelectric material and matching layer together.

[0024] In some embodiments, the circuit board protrudes beyond the side edges of the sound-absorbing layer, the piezoelectric material, and the matching layer to allow the lead wires to connect to the circuit board.

[0025] In some embodiments, after pre-forming a pre-formed tube by covering one end of the lead wire with polymer material at a predetermined distance, the method further includes the following steps:

[0026] A sheath made of the same material as the preformed tube is installed around the lead wire, and the sheath and the preformed tube are fixedly connected by high-temperature melting or laser welding.

[0027] In some embodiments, the method of using separate casting to create a sound-permeable protective layer covering the outer periphery of the array stack and the preformed tube near the array stack includes the following steps:

[0028] At one end of the array stack and the preformed tube near the array stack, the first component of the sound-permeable protective layer is cast and molded.

[0029] After the first component has solidified, the second component of the sound-permeable protective layer is poured and formed. During pouring, the edge of the first component combines with the liquid material injected during the pouring of the second component.

[0030] The second component is solidified to form a complete sound-permeable protective layer;

[0031] The sound-permeable protective layer is made of silicone rubber or PDMS;

[0032] or

[0033] The first component of the cast-molded sound-permeable protective layer;

[0034] The second component of the cast-molded sound-permeable protective layer;

[0035] Solidify the first and second parts;

[0036] The cured first and second parts are placed on the outer periphery of the array stack and the preformed tube near the array stack, and the first and second parts are bonded together to form a complete sound-permeable protective layer.

[0037] The sound-permeable protective layer is made of TPX, Rexolite, or Pebax.

[0038] The present invention also provides an ultrasonic catheter, which is manufactured using the ultrasonic catheter manufacturing method provided in any of the above claims.

[0039] In some embodiments, the array stack includes stacked circuit boards, sound-absorbing layers, piezoelectric material layers, and matching layers;

[0040] The circuit board, the sound-absorbing layer, the piezoelectric material layer, and the matching layer are stacked sequentially, or the sound-absorbing layer, the circuit board, the piezoelectric material layer, and the matching layer are stacked sequentially.

[0041] The sound-permeable protective layer has an emitting surface on the side away from the preformed tube, and the emitting surface is located on the outer wall of the sound-permeable protective layer opposite to the matching layer.

[0042] The present invention also provides a molding die for molding the ultrasonic catheter provided in any of the preceding claims, comprising:

[0043] First molding module, second molding module, and support block;

[0044] The support block has a first groove and a second groove that are connected to each other. The first groove is adapted to the shape and contour of the array stack, and the second groove has a semi-circular cross-section adapted to the maximum outer diameter of the preformed tube.

[0045] The first molding module is provided with a third groove and a first pouring channel, the first pouring channel being connected to the third groove;

[0046] When the first molding module and the support block are engaged, the first groove, the second groove, and the third groove together form a first molding cavity. An integrated array of layers, lead wires, and pre-formed tubes are placed within the first and second grooves. The poured liquid material enters the first molding cavity through the first pouring channel to form the first component of the sound-permeable protective layer.

[0047] The second molding module is provided with a fourth groove and a second pouring channel, the second pouring channel being connected to the fourth groove;

[0048] When the first molding module and the second molding module are engaged, the fourth groove, together with the integrated first split, array stack, lead wire and pre-formed tube, forms the second molding cavity. The poured liquid material enters the second molding cavity through the second pouring channel to form the second split of the sound-permeable protective layer.

[0049] The first and second components are tightly combined to form the sound-permeable protective layer.

[0050] In some embodiments, the sound-permeable protective layer has an emitting surface on the side away from the preformed tube, and the emitting surface is located on the outer wall of the sound-permeable protective layer;

[0051] The first molding module includes a first mold parting and a second mold parting;

[0052] The first mold has a first slot and a second slot. The first slot is adapted to the shape and contour of the outer wall of the sound-permeable protective layer, and the second slot is adapted to the shape and contour of the emitting surface of the sound-permeable protective layer. The first casting channel is connected to the first slot.

[0053] The second mold is provided with a third groove, which is adapted to the shape and contour of the end of the sound-permeable protective layer away from the preformed tube;

[0054] After the first and second molds are combined, the first groove, the second groove, and the third groove together form the third groove.

[0055] The technical advantages of this invention are as follows:

[0056] 1. In this patent, by coating the outer surface of the acoustic protective layer with a Parylene coating, the acoustic protective layer can better adapt to the vascular environment of the human body and meet the requirements for intravascular use. Conversely, because the Parylene coating on the outside of the acoustic protective layer enables it to meet the requirements for intravascular use, a wider range of materials can be selected for its fabrication. Considering that in existing protective layer molding methods, the array stack often detaches due to excessively high melting temperatures, preventing the ultrasonic catheter from transmitting or receiving ultrasound waves and affecting its acoustic performance, this patent allows the use of materials with lower casting temperatures to fabricate the acoustic protective layer. This avoids the array stack detaching due to heat, thereby improving the acoustic performance of the ultrasonic catheter. Furthermore, casting molding allows for better control of the uniformity of the acoustic protective layer, thus improving the performance consistency and yield rate of the ultrasonic catheter.

[0057] 2. This patent features a groove on the outer wall of the preformed tube. In this way, during the casting process, the molten material can flow into the groove. After the molten material solidifies, the groove and the sound-permeable protective layer formed after solidification can be tightly bonded together, resulting in high connection strength and preventing loosening.

[0058] 3. In this patent, the side of the acoustic protective layer away from the preformed tube is provided with an emitting surface, and this emitting surface is located on the outer wall of the acoustic protective layer directly opposite the matching layer. This facilitates the focusing of sound waves in the short axis direction, reduces the thickness of the imaging slice, and improves the image resolution. Furthermore, to prevent sound waves from rapidly diverging outside the focal point, the emitting surface in this patent can also be set as a convex or concave arc surface, ensuring that the focal length formed by the acoustic protective layer is greater than or equal to the natural focal length of the array element without the acoustic protective layer. Attached Figure Description

[0059] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0060] Figure 1 It is the outer contour of the protective layer in the prior art;

[0061] Figure 2 This is a cross-sectional view of the protective layer and array stack in the prior art;

[0062] Figure 3 This is a partial structural disassembly diagram of the ultrasonic catheter provided by the present invention;

[0063] Figure 4 This is a partially enlarged schematic diagram of the preformed tube provided by the present invention facing one end of the array stack;

[0064] Figure 5 This is a schematic diagram of the three-dimensional structure of the stacked layer provided in one embodiment of the present invention;

[0065] Figure 6 This is a schematic diagram of the three-dimensional structure of the stacked layer provided in another embodiment of the present invention;

[0066] Figure 7 This is a three-dimensional structural diagram of one end of the ultrasonic catheter provided by the present invention, which has an acoustic protective layer.

[0067] Figure 8 This is a three-dimensional structural diagram of the sound-permeable protective layer provided in one embodiment of the present invention;

[0068] Figure 9 This is a three-dimensional structural diagram of the sound-permeable protective layer provided in another embodiment of the present invention;

[0069] Figure 10 This is a three-dimensional structural schematic diagram of the sound-permeable protective layer provided in yet another embodiment of the present invention;

[0070] Figure 11 This is a three-dimensional structural schematic diagram of the ultrasonic catheter provided by the present invention;

[0071] Figure 12 This is a disassembly diagram of the first component of the sound-permeable protective layer made from the first molding module and support block provided by the present invention;

[0072] Figure 13 This is a cross-sectional schematic diagram of the first component of the sound-permeable protective layer made by the first molding module and support block provided by the present invention;

[0073] Figure 14 This is a disassembly diagram of the second component of the sound-permeable protective layer fabricated by the first molding module and the second molding module provided by the present invention;

[0074] Figure 15 This is a cross-sectional schematic diagram of the second component of the sound-permeable protective layer fabricated by the first molding module and the second molding module provided by the present invention.

[0075] Explanation of icon numbers:

[0076] 100. Array stack; 110. Circuit board; 120. Sound-absorbing layer; 130. Piezoelectric material; 140. Matching layer; 150. Backing;

[0077] 200. Lead wire;

[0078] 300. Preformed tube; 310. Grooved;

[0079] 400. Sound-transmitting protective layer; 410. Emitting surface; 420. Slope; 430. First component; 440. Second component;

[0080] 500. Line connector;

[0081] 600. Sheath;

[0082] 700. Control handle;

[0083] 810. First molding module; 811. First mold parting; 8111. First slot; 8112. Second slot; 812. Second mold parting; 8121. Third slot; 813. First gating channel; 820. Second molding module; 821. Fourth groove; 822. Second gating channel; 830. Support block; 831. First groove; 832. Second groove;

[0084] 400', protective layer. Detailed Implementation

[0085] In the following description, specific details such as particular system architectures and techniques are set forth for illustrative purposes and not for limitation, in order to provide a thorough understanding of the embodiments of this application. However, those skilled in the art will understand that this application can also be implemented in other embodiments without these specific details. In other instances, detailed descriptions of well-known systems, apparatuses, circuits, and methods have been omitted so as not to obscure the description of this application with unnecessary detail.

[0086] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the specific implementation methods of the present invention will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of the present invention. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0087] To keep the drawings concise, each figure only schematically shows the parts relevant to the invention, and these do not represent the actual structure of the product. Furthermore, to facilitate understanding, in some figures, only one of components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0088] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0089] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0090] In the embodiments shown in the accompanying drawings, the directional indications (such as up, down, left, right, front, and back) used to explain the structure and movement of the various components of the invention are relative rather than absolute. These descriptions are appropriate when these components are in the positions shown in the drawings. If the descriptions of the positions of these components change, these directional indications also change accordingly.

[0091] Furthermore, in the description of this application, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0092] According to a specific embodiment of the present invention, a method for manufacturing an ultrasonic catheter is provided. The specific structure of the ultrasonic catheter can be found in [reference needed]. Figure 3 and Figure 11 .

[0093] The specific steps involved in this production method are as follows:

[0094] 100 prefabricated array stacks;

[0095] The lead wire 200 is selected. The lead wire 200 can be a coaxial cable, a flexible circuit board, or a combination of the two. That is, part of the lead wire 200 is a coaxial cable and part is a flexible circuit board. There are no restrictions here, and all are within the protection scope of the present invention.

[0096] A certain distance is preset at one end of the lead wire 200, and a polymer material is wrapped around it to form a preformed tube 300. The polymer material includes, but is not limited to, Pebax, PEEK (Poly ether ether ketone), TPE (Thermoplastic rubber), etc.

[0097] One end of the lead wire 200 near the preformed tube 300 is electrically connected to the array stack 100;

[0098] A sound-permeable protective layer 400 is made by separate casting, which covers the outer periphery of the array stack 100 and the preformed tube 300 near the array stack 100.

[0099] One end of the lead wire 200 away from the preformed tube 300 is electrically connected to the line connector 500, wherein the line connector 500 is used to interface with various image diagnostic systems;

[0100] A Parylene coating is formed on the outer surface of the sound-permeable protective layer 400. Depending on the actual needs of different product specifications, the thickness of the Parylene coating is generally controlled between 1 micrometer and 20 micrometers.

[0101] This embodiment employs a split-cast acoustic protective tube and adds a process to the production of the ultrasonic catheter by depositing a Parylene coating on the outer surface of the acoustic protective layer 400. Parylene is a protective polymer material, also known as poly(p-xylene). The Parylene coating not only possesses excellent electrical and protective properties but also good biocompatibility. It has been approved by the US FDA and meets the US Pharmacopeia Class VI standard for biomedical materials, classifying it as a biomedical material suitable for long-term implantation in the body. Therefore, the Parylene coating allows the acoustic protective layer 400 to adapt well to the vascular environment of the human body, meeting the requirements for intravascular use.

[0102] In contrast, because the Parylene coating on the outside of the acoustic protective layer 400 enables the acoustic protective layer 400 to meet the requirements for intravascular use, a wider variety of materials can be selected when manufacturing the acoustic protective layer 400, which can reduce material costs to some extent.

[0103] Considering the existing molding method of coating the array stack 100 with molten material and solidifying it to form a protective layer 400', the material often melts at too high a temperature, causing the layers of the array stack 100 to separate, preventing the ultrasonic conduit from transmitting or receiving ultrasonic waves and affecting its acoustic performance. In this embodiment, a material with a lower casting temperature can be used to make the sound-transmitting protective layer 400 to prevent the layers of the array stack 100 from separating due to heat, thereby improving the acoustic performance of the ultrasonic conduit.

[0104] Specifically, the sound-permeable protective layer 400 is cast from silicone rubber or PDMS (Polydimethylsiloxane, such as RTV615) at room temperature. That is, when using split casting, the first segment 430 of the sound-permeable protective layer 400 is first cast at one end of the array stack 100 and the preformed tube 300 near the array stack 100. After the first segment 430 cures, the second segment 440 of the sound-permeable protective layer 400 is then cast. At this point, the edge of the first segment 430 bonds with the liquid material injected during the casting of the second segment 440. After the newly cast second segment 440 cures, a complete sound-permeable protective layer 400 is formed.

[0105] The first and second components 430 and 440, when cast, can be placed in an oven for curing, with the curing temperature not exceeding 110°C. In the prior art, to prevent the materials of each layer of the array stack 100 from separating due to excessively high temperatures of the cast molten material, another method for forming the protective layer 400' is available; see [link to relevant documentation]. Figure 1 and Figure 2 First, a protective layer 400' is pre-formed using Pebax material. Then, UV adhesive is applied to the outer surface of the array stack 100 and / or the inner surface of the protective layer 400'. Taking advantage of the transparency of Pebax material, the UV adhesive is used to bond the Pebax protective layer 400' to the array stack 100 by applying a UV lamp.

[0106] Since the protective layer 400' is a structure that covers the outer periphery of the array stack 100 and the preformed tube 300 near the array stack 100, and one end of it is closed, when using UV adhesive or epoxy adhesive to bond the preformed protective layer 400' to the array stack 100 and the preformed tube 300 near the array stack 100, there will be problems with the thickness and uniformity of the adhesive layer. Once the thickness of the adhesive layer exceeds 10 micrometers, it will inevitably have an adverse effect on the acoustic performance (such as sensitivity, bandwidth, etc.), performance consistency (i.e., the consistency of the performance of the array elements on the array stack 100 and the consistency of the performance of different ultrasonic catheters produced), and pass rate of the array stack 100 and the entire ultrasonic catheter.

[0107] The ultrasonic conduit manufacturing method provided in this embodiment is less prone to this problem. It can effectively control the shape and thickness of the sound-transmitting protective layer 400 by using split casting, producing a sound-transmitting protective layer 400 with uniform thickness and close fit to the array stack 100. It can also select materials with casting temperature and curing temperature not exceeding 110°C to manufacture the sound-transmitting protective layer 400, avoiding the separation of the materials of each layer of the array stack 100 due to heat. This results in the manufacture of an ultrasonic conduit with good acoustic performance and ensures that the ultrasonic conduit has good performance consistency and a high pass rate.

[0108] Of course, for materials with a melting temperature exceeding 110°C, such as TPX (a polymer of 4-methylpentene), Rexolite (a unique cross-linked polystyrene microwave plastic), Pebax, or RTV615 (polydimethylsiloxane, also known as PDMS, a low-viscosity, high-strength, heat-curing medical liquid), the first component 430 and the second component 440 of the sound-permeable protective layer 400 can be pre-formed, and then the first component 430 and the second component 440 can be bonded together to form a complete sound-permeable protective layer.

[0109] It is worth noting that the order of steps in the method for manufacturing the ultrasonic catheter provided in this embodiment can be adjusted according to actual conditions. For example, after fabricating the acoustically transparent protective layer 400 covering the outer periphery of the array stack 100 and the preformed tube 300 near the array stack 100 using separate casting, a Parylene coating can be formed on the outer surface of the acoustically transparent protective layer 400 first, and then the end of the lead wire 200 away from the preformed tube 300 can be electrically connected to the line connector 500. Alternatively, after electrically connecting the end of the lead wire 200 near the preformed tube 300 to the array stack 100, the end of the lead wire 200 away from the preformed tube 300 can be electrically connected to the line connector 500 first, and then the acoustically transparent protective layer 400 covering the outer periphery of the array stack 100 and the preformed tube 300 near the array stack 100 can be fabricated using separate casting. These methods are also feasible and are not limited here, and are all within the protection scope of this invention.

[0110] In a preferred embodiment, see Figure 4 , Figure 13 and Figure 15 The outer wall of the preformed tube 300 is provided with a groove 310. In this way, during the casting process, the groove 310 can be used to allow the liquid material to flow in; when the liquid material to be cast solidifies, the groove 310 and the sound-permeable protective layer 400 formed after solidification are tightly bonded to strengthen the connection between the preformed tube 300 and the sound-permeable protective layer 400.

[0111] In the production process, the groove 310 can be formed by processing the outer wall of the preformed tube 300 after it has been made into a preformed tube 300 using external tools; or it can be formed together with the preformed tube 300, such as by setting up a corresponding mold and directly forming the preformed tube 300 with grooves by casting. Further details are omitted here, and all of these are within the protection scope of this invention.

[0112] Specifically, the slot 310 can be a concave structure, with multiple slots 310 evenly spaced on the outer wall of the preformed tube 300; or, the slot 310 can be a ring structure, arranged around the outer wall of the preformed tube 300, with multiple slots 310 forming a wavy structure on the outer wall of the preformed tube 300; or, there can be only one slot 310, arranged around the outer wall of the preformed tube 300, so that the end of the preformed tube 300 facing the array stack 100 forms a frustum structure, with the large end of the frustum facing the array stack 100 and the small end of the frustum away from the array stack 100.

[0113] Of course, in actual production, the slot 310 can also adopt other structural settings, which will not be elaborated here. As long as it can strengthen the connection between the preformed tube 300 and the sound-permeable protective layer 400, it is within the protection scope of this invention.

[0114] Specifically, see Figure 13 and Figure 15 The lead wire 200 has a pre-set distance of 0.5mm to 20mm at one end, that is, a length of 0.5mm to 20mm is reserved at one end of the lead wire 200, and then a portion of polymer conduit material is melted or bonded on it. The reserved length is used for electrical connection with the array stack 100 in subsequent steps.

[0115] Specifically, the prefabricated array stack 100 includes the following steps:

[0116] See Figure 5 and Figure 6 First, the circuit board 110, the sound-absorbing layer 120, the piezoelectric material 130, and the matching layer 140 are bonded together in a stacked manner; then, according to the number of array elements, the bonded piezoelectric material 130 and the matching layer 140 are cut, or, according to the number of array elements, the bonded sound-absorbing layer 120, the piezoelectric material 130, and the matching layer 140 are cut.

[0117] In this embodiment, the piezoelectric material 130 can be a piezoelectric composite material, a piezoelectric single crystal, a piezoelectric ceramic, or other materials with piezoelectric properties, or materials using microelectromechanical processing technology such as CMUT or PMUT. The matching layer 140 is a sound-transmitting material with an acoustic impedance between 1.5 MRayl and 40 MRayl, and can consist of zero to five layers. The matching layer 140 is located at the front end of the piezoelectric material 130, close to the object being ultrasonically inspected, while the sound-absorbing layer 120 is located at the rear end of the piezoelectric material 130, used to support the piezoelectric material 130 and absorb the back-propagating ultrasonic signal, reducing the tail oscillation of the front-emitted ultrasonic signal. Typically, the acoustic impedance of the sound-absorbing layer 120 is between 1.5 MRayl and 150 MRayl. The circuit board 110 is located between the piezoelectric material 130 and the sound-absorbing layer 120 or on the other side of the sound-absorbing layer 120, serving to extract the array element signal.

[0118] It is worth noting that the number of array elements can range from 1 to 10,000, and their arrangement can be as follows: Figure 5 The one-dimensional array arrangement shown can also be as follows: Figure 6 The two-dimensional array arrangement shown is not limited here and is within the protection scope of this invention.

[0119] Specifically, see Figure 5 , Figure 6 , Figure 13 and Figure 15 When fabricating the array stack 100, the circuit board 110 should protrude beyond the side edges of the sound-absorbing layer 120, the piezoelectric material 130, and the matching layer 140. The protruding portion is used for the lead wire 200 to be connected to the circuit board 110. In this embodiment, the width of the circuit board 110 is the same as the width of the sound-absorbing layer 120, the piezoelectric material 130, and the matching layer 140, while the length of the circuit board 110 is greater than the length of the sound-absorbing layer 120, the piezoelectric material 130, and the matching layer 140, to form the protruding portion.

[0120] Subsequently, the lead wire 200 is connected to the connecting plate of the protruding part of the circuit board 110 by welding or bonding, so as to conduct the array element signal path on the circuit board 110 to the line connector 500, and then to the channel and the line connector 500 to connect to various image diagnostic systems.

[0121] See Figure 3 , Figure 7 and Figures 11 to 15 In one specific embodiment, after the step of covering one end of the lead wire 200 with polymer material at a predetermined distance to form a pre-formed tube 300, the following step is also included:

[0122] A sheath 600 made of the same material as the preformed tube 300 is installed over the lead wire 200, and the sheath 600 and the preformed tube 300 are fixedly connected by high-temperature melting or laser welding.

[0123] Among them, see Figure 4 , Figure 13 and Figure 15 On the outer wall of the preformed tube 300, a ring-shaped boss is provided on the side of the slot 310 away from the array stack 100. The outer diameter of this ring-shaped boss is the maximum outer diameter of the preformed tube 300. When the sheath 600 is integrated into the outer wall of the lead wire and fixedly connected to the preformed tube 300, the end of the sheath 600 fits against the ring-shaped boss, and the outer diameter of the ring-shaped boss is the same as the outer diameter of the sheath 600. Correspondingly, the cast protective layer 400 also abuts against the ring-shaped boss of the preformed tube 300, and the outer surface contour of the protective layer 400 is cylindrical, and its outer diameter is also the same as the outer diameter of the ring-shaped boss. In this way, it can be ensured that the outer surface of the manufactured ultrasonic catheter is free of protrusions, making it easier to enter and exit human blood vessels and less likely to cause damage to human blood vessels, reducing patient discomfort.

[0124] As a preferred option, see Figure 7 The protective layer 400 has a spherical end away from the preformed tube 300, which can further improve the surface smoothness of the ultrasound catheter and reduce patient discomfort during the operation.

[0125] It is worth noting that the step of fixing the sheath 600 and the preformed tube 300 does not necessarily have to be completed after the preformed tube 300 is formed. It can be done after the sound-permeable protective layer 400 is formed or after the Parylene coating is formed on the outer surface of the sound-permeable protective layer 400. There is no limitation here. The order of production steps can be flexibly adjusted according to the actual situation, and all of them are within the protection scope of this invention.

[0126] The present invention also provides an ultrasonic catheter, see below. Figures 3 to 11 The ultrasonic catheter is manufactured using the ultrasonic catheter manufacturing method provided in any of the above embodiments.

[0127] Specifically, see Figures 5 to 7 The sound-transmitting protective layer 400 has an emitting surface 410 at one end away from the preformed tube 300. This emitting surface 410 is located on the outer wall of the sound-transmitting protective layer 400, directly opposite the matching layer 140. This facilitates the focusing of sound waves in the short axis direction, i.e., the width direction of the circuit board 110, reducing the thickness of the imaging slice and improving the image resolution. See also... Figures 8 to 10 The emitting surface 410 can be a plane, a convex arc surface, or a concave arc surface. These can be described in detail here, and all are within the protection scope of this invention.

[0128] It is worth noting that the emitting surface 410 is a convex arc surface or a concave arc surface, which provides a better focusing effect compared to a flat surface 410.

[0129] As a preferred option, see Figures 7 to 10 The emitting surface 410 on the acoustic protective layer 400 and the outer wall of the acoustic protective layer 400 are connected by a slope 420, which can improve the surface smoothness of the ultrasound catheter to a certain extent and reduce the patient's discomfort during the operation.

[0130] Of course, in actual production, the emitting surface 410 on the sound-transmitting protective layer 400 and the outer wall of the sound-transmitting protective layer 400 can also be connected by an arc transition. This is not a limitation and is within the protection scope of the present invention.

[0131] In one specific embodiment, see Figure 11 The sheath is also equipped with a control handle 700, which is electrically connected to the circuit board 110 on the array stack 100, for medical staff to control the operation of the ultrasound catheter during the operation.

[0132] This invention also provides a molding die, see [link to related document]. Figures 12 to 15 This molding die is used to form the ultrasonic conduit provided in any of the above embodiments. Specifically, the molding die includes a first molding module 810, a second molding module 820, and a support block 830. The support block 830 has a first groove 831 and a second groove 832 that are connected. The first groove 831 is adapted to the shape and contour of the array stack 100, and the second groove 832 has a semi-circular cross-section adapted to the maximum outer diameter of the preformed tube 300. The first molding module 810 has a third groove and a first casting channel 813, which is connected to the third groove. When the first molding module 810 and the support block 830 are engaged, the first groove 831, the second groove 832, and the third groove together form a first molding cavity. The integrated array stack 100, lead wire 200, and preformed tube 300 are placed in the first groove 831 and the second groove 832. The poured molten material enters the first molding cavity through the first casting channel 813 to form the first component 430 of the sound-permeable protective layer 400. The second molding module 820 is provided with a fourth groove 821 and a second pouring channel 822, the second pouring channel 822 being connected to the fourth groove 821. When the first molding module 810 and the second molding module 820 are engaged, the fourth groove 821, together with the integrated first sub-unit 430, array stack 100, lead wire 200 and pre-formed tube 300, form a second molding cavity. The poured molten material enters the second molding cavity through the second pouring channel 822 to form the second sub-unit 440 of the sound-permeable protective layer 400.

[0133] In the second part 440, since the material being poured is a liquid material and the molding material used for the first part 430 is the same material, the liquid material can be tightly bonded to the first part 430 after solidification, thereby forming a complete sound-permeable protective layer 400.

[0134] In this embodiment, the first groove 831 and the second groove 832 on the support block 830 are mainly used to position the integrated array stack 100, lead wire 200 and preformed tube 300 to ensure accurate casting position.

[0135] The third and fourth grooves 821 are adapted to the outer surface contour of the protective layer 400 of the ultrasonic conduit provided by the present invention, so as to ensure that the protective layer 400 formed after casting meets the actual needs.

[0136] Specifically, see Figures 12 to 15 The first molding module 810 includes a first parting mold 811 and a second parting mold 812. The first parting mold 811 has a first groove 8111 and a second groove 8112. The first groove 8111 is adapted to the shape and contour of the outer wall of the sound-permeable protective layer 400, and the second groove 8112 is adapted to the shape and contour of the emitting surface 410 of the sound-permeable protective layer 400. A first casting channel 813 is connected to the first groove 8111. The second parting mold 812 has a third groove 8121, adapted to the shape and contour of the end of the sound-permeable protective layer 400 away from the preformed tube 300. After the first parting mold 811 and the second parting mold 812 are combined, the first groove 8111, the second groove 8112, and the third groove 8121 together form a third groove.

[0137] Of course, in actual production, the first mold 811 and the second mold 812 can be fixedly connected by screws or can be set up as an integrally formed structure. There are no restrictions here, and both are within the protection scope of the present invention.

[0138] Specifically, see Figure 5 , Figure 6 and Figures 12 to 15 Taking the use of silicone rubber casting protective layer 400 as an example, a backing 150 is first fixed in the first groove 831 of the support block 830, and then the array stack 100 is fixed by the backing 150. The preformed tube 300 connected to the array stack 100 is placed in the second groove 832, thereby controlling the position of the array stack 100 and the preformed tube 300.

[0139] Next, the first molding module 810 is installed, and the support block 830 and the first molding module 810 are fixed with screws. After fixing, glue is injected into the first molding cavity through the first pouring channel 813. After the glue is injected, it is cured at a temperature below 110°C. At this time, the glue seals the first pouring channel 813, forming the first split part 430.

[0140] After the adhesive cures, remove the support block 830. If the circuit board 110 extends beyond the backing material 150, fold the circuit board 110 according to the width of the sound-absorbing layer 120, piezoelectric material 130, and matching layer 140, and fix it to the backing 150. At this time, the first molding module 810 remains stationary. After fixing the circuit board 110, remove the support block 830 and fix the second molding module 820 in the original position of the support block 830. Inject adhesive into the second molding cavity through the second pouring channel 822. After the adhesive is injected, cure it at a temperature below 110°C to finally form the entire protective layer 400.

[0141] By employing the two-stage injection molding method mentioned above, it is possible to position the array stack 100, control the thickness and shape of the sound-transmitting protective layer 400, and combine the sound-transmitting protective layer 400 with the lead wire 200, which is highly practical.

[0142] In actual production, the replacement and assembly of components involved in the two pouring processes can be carried out manually or automatically. This will not be elaborated on here, as all of these processes are within the scope of protection of this invention.

[0143] In contrast, besides the casting method provided in the above embodiments, in actual production, the first component 430 and the second component 440 can also be pre-formed using a casting molding method, and then assembled using a mold to form a complete protective layer 400. In this case, the pressure generated by the mold assembly can be used to control the uniformity of the adhesive layer and ensure the acoustic performance of the ultrasonic conduit.

[0144] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0145] It should be noted that the above embodiments can be freely combined as needed. The above are merely preferred embodiments of the present invention. It should be pointed out that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for manufacturing an ultrasonic catheter, characterized in that, Including the following steps: Prefabricated array stack; Select the lead wire; A pre-formed tube is made by covering a polymer material at a predetermined distance from one end of the lead wire. Electrically connect the end of the lead wire closest to the preformed tube to the array stack; A sound-permeable protective layer is created by using a split casting process to cover the outer periphery of the array stack and the preformed tube near the array stack. Electrically connect the end of the lead wire away from the preformed tube to the line connector; A Parylene coating is formed on the outer surface of the acoustically permeable protective layer; The method of using split casting to create a sound-permeable protective layer covering the outer periphery of the array stack and the preformed tube near the array stack includes the following steps: At one end of the array stack and the preformed tube near the array stack, the first component of the sound-permeable protective layer is cast and molded. After the first component has solidified, the second component of the sound-permeable protective layer is poured and formed. During pouring, the edge of the first component combines with the liquid material injected during the pouring of the second component. The second component is cured to form a complete sound-permeable protective layer, which is made of silicone rubber or PDMS. or The first component of the cast-molded sound-permeable protective layer; The second component of the cast-molded sound-permeable protective layer; Solidify the first and second parts; The cured first and second parts are placed on the outer periphery of the array stack and the preformed tube near one end of the array stack, and the first and second parts are bonded together to form a complete sound-permeable protective layer, which is made of TPX, Rexolite or Pebax.

2. The method for manufacturing an ultrasonic catheter according to claim 1, characterized in that... , The outer wall of the preformed tube is provided with a groove; During the casting process, the groove allows the liquid material to flow in; the liquid material to be cast solidifies, and the groove is tightly bonded to the sound-permeable protective layer formed after solidification, so as to strengthen the connection strength between the preformed tube and the sound-permeable protective layer. The liquid material is poured at room temperature and the curing temperature does not exceed 110℃.

3. The method for manufacturing an ultrasonic catheter according to claim 1 or 2, characterized in that, The aforementioned prefabricated array stack includes the following steps: The circuit board, sound-absorbing layer, piezoelectric material and matching layer are bonded together in a stacked manner; Depending on the number of array elements, cut and bond the piezoelectric material and matching layer together, or, depending on the number of array elements, cut and bond the sound-absorbing layer, piezoelectric material and matching layer together.

4. The method for manufacturing an ultrasonic catheter according to claim 3, characterized in that, The circuit board protrudes from the side edges of the sound-absorbing layer, the piezoelectric material, and the matching layer, so that the lead wires can be connected to the circuit board.

5. The method for manufacturing an ultrasonic catheter according to claim 1 or 2, characterized in that, After preforming a pre-formed tube by covering one end of the lead wire with polymer material at a predetermined distance, the process further includes the following steps: A sheath made of the same material as the preformed tube is installed around the lead wire, and the sheath and the preformed tube are fixedly connected by high-temperature melting or laser welding.

6. An ultrasonic catheter, characterized in that, It is manufactured using the method described in any one of claims 1-5 for the fabrication of an ultrasonic catheter.

7. The ultrasonic catheter according to claim 6, characterized in that, The array stack includes stacked circuit boards, sound-absorbing layers, piezoelectric material layers, and matching layers; The circuit board, the sound-absorbing layer, the piezoelectric material layer, and the matching layer are stacked sequentially, or the sound-absorbing layer, the circuit board, the piezoelectric material layer, and the matching layer are stacked sequentially. The sound-permeable protective layer has an emitting surface on the side away from the preformed tube, and the emitting surface is located on the outer wall of the sound-permeable protective layer opposite to the matching layer.

8. A molding die, characterized in that, For forming the ultrasonic catheter of claim 6 or 7, comprising: First molding module, second molding module, and support block; The support block has a first groove and a second groove that are connected to each other. The first groove is adapted to the shape and contour of the array stack, and the second groove has a semi-circular cross-section adapted to the maximum outer diameter of the preformed tube. The first molding module is provided with a third groove and a first pouring channel, the first pouring channel being connected to the third groove; When the first molding module and the support block are engaged, the first groove, the second groove, and the third groove together form a first molding cavity. An integrated array of layers, lead wires, and pre-formed tubes are placed within the first and second grooves. The poured liquid material enters the first molding cavity through the first pouring channel to form the first component of the sound-permeable protective layer. The second molding module is provided with a fourth groove and a second pouring channel, the second pouring channel being connected to the fourth groove; When the first molding module and the second molding module are engaged, the fourth groove, together with the integrated first split, array stack, lead wire and pre-formed tube, forms the second molding cavity. The poured liquid material enters the second molding cavity through the second pouring channel to form the second split of the sound-permeable protective layer. The first and second components are tightly combined to form the sound-permeable protective layer.

9. The molding die according to claim 8, characterized in that, The sound-permeable protective layer has an emitting surface on the side away from the preformed tube, and the emitting surface is located on the outer wall of the sound-permeable protective layer; The first molding module includes a first mold parting and a second mold parting; The first mold has a first slot and a second slot. The first slot is adapted to the shape and contour of the outer wall of the sound-permeable protective layer, and the second slot is adapted to the shape and contour of the emitting surface of the sound-permeable protective layer. The first casting channel is connected to the first slot. The second mold is provided with a third groove, which is adapted to the shape and contour of the end of the sound-permeable protective layer away from the preformed tube; After the first and second molds are combined, the first groove, the second groove, and the third groove together form the third groove.

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