Interventional variable-focus ultrasonic catheter

Abstract

The embodiment of the invention provides an intrusive variable-focus ultrasonic catheter. The intrusive variable-focus ultrasonic catheter comprises an inner tube and an outer tube, the inner pipe is sleeved with the outer pipe, the outer pipe comprises a first fixed section fixed relative to the inner pipe and a slidable section capable of sliding in the axial direction relative to the inner pipe, the slidable section comprises a bendable section, and when the bendable section slides towards the first fixed section, the bendable section is bent into a bent shape which is inwards sunken from the two ends to the middle on the whole; the ultrasonic transducer arrays are arranged on the bendable section and arranged at intervals in the circumferential direction, and each ultrasonic transducer array comprises a plurality of ultrasonic transducers arranged at intervals in the axial direction. According to the interventional variable-focus ultrasonic catheter, the local intensity of ultrasound can be enhanced, the local treatment effect of the ultrasound can be improved, the action range of the ultrasound in the circumferential direction and the radial direction can be enlarged, and the treatment range and treatment efficiency of the ultrasound are remarkably improved.

Description

Technical Field

[0001] The present application relates to the technical field of medical catheters, and in particular to an invasive variable-focus ultrasound catheter. Background Art

[0002] Intravascular nerve ablation is an interventional treatment method used to relieve the symptoms of certain neurological diseases, such as hypertension and pulmonary hypertension caused by overactivation of the sympathetic nerves. During the treatment, a catheter is inserted into the blood vessels corresponding to the nerves, and then the nerve tissue in the target area is destroyed through radiofrequency ablation, ultrasonic ablation, cryoablation, chemical ablation, etc. to achieve the treatment purpose. Taking renal sympathetic denervation to treat hypertension as an example, there are renal afferent and efferent sympathetic nerves distributed around the renal artery. The nerves are 2mm to 7mm away from the blood vessel wall and are distributed around the blood vessels.

[0003] In clinical practice, it is necessary to completely ablate the nerves around the blood vessels in a 360° direction to achieve the therapeutic effect. Compared with radiofrequency ablation, ultrasound has the advantage of a wide radiation range, so it is easier to achieve a deeper ablation depth. However, due to the small diameter of the interventional catheter, it is difficult for the ultrasound transducer to obtain higher radiation power by increasing its size. Although the local ultrasound intensity can be enhanced by focusing, it also limits the scope of treatment.

[0004] It should be noted that the above introduction to the background technology is only for the convenience of providing a clear and complete description of the technical solutions of the present application and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well known to those skilled in the art simply because they are described in the background technology section of the present application. Summary of the invention

[0005] The purpose of the present application is to provide an invasive variable-focus ultrasound catheter to solve the problems pointed out in the above background technology or other similar problems.

[0006] An embodiment of the present application provides an interventional variable-focus ultrasound catheter, comprising: an inner tube; an outer tube, which is sleeved outside the inner tube and comprises a first fixed section fixed relative to the inner tube, and a slidable section that can slide relative to the inner tube in an axial direction, the slidable section comprising a bendable section, and the bendable section is bent into a curved shape that is concave inward from both ends to the middle as a whole when the slidable section slides toward the first fixed section; a plurality of ultrasonic transducer arrays, which are arranged in the bendable section and spaced apart in the circumferential direction, each ultrasonic transducer array comprises a plurality of ultrasonic transducers spaced apart in the axial direction, the ultrasonic waves generated by the plurality of ultrasonic transducers of each ultrasonic transducer array are focused when the bendable section is in the curved shape, the change in the bending amplitude of the bendable section changes the focal length of the ultrasonic wave, and the focusing positions of the ultrasonic waves emitted by the ultrasonic transducers of the plurality of ultrasonic transducer arrays are distributed within the entire circumferential range outside the outer tube.

[0007] In some embodiments, the bendable segment comprises a plurality of bendable bands, the plurality of bendable bands are at least partially spaced apart in the circumferential direction, each of the bendable bands extends along the axial direction, each of the ultrasonic transducer arrays is respectively arranged on one of the bendable bands, and the plurality of ultrasonic transducers of each of the ultrasonic transducer arrays are spaced apart along the axial direction on the bendable band.

[0008] In some embodiments, the middle portions of the plurality of bendable bands are sequentially connected in a circumferential direction to form a first connecting ring, and the first connecting ring limits the bending of the middle portion of each bendable band when the bendable segment is bent.

[0009] In some embodiments, each of the flexible bands is provided with a plurality of folding grooves on its outer surface facing away from the inner tube, which cause the flexible segment to bend into the curved shape. The plurality of folding grooves are arranged at intervals along the length direction of the flexible band, and each of the folding grooves extends along the width direction of the flexible band.

[0010] In some embodiments, each of the bendable strips is provided with a metal foil for causing the bendable segment to bend into the bent shape, and the metal foil has a pre-deformed shape that is the same as the bent shape.

[0011] In some embodiments, the metal foil is electrically connected to the ultrasonic transducer as an electrode of the ultrasonic transducer.

[0012] In some embodiments, the metal foil is disposed on the outer surface of the bendable segment facing away from the inner tube; or, the metal foil is embedded in the side wall of the bendable segment; or, the metal foil is disposed on the inner surface of the bendable segment facing the inner tube.

[0013] In some embodiments, the ultrasonic transducer is disposed on the outer surface of the bendable segment facing away from the inner tube; or, the ultrasonic transducer is embedded in the side wall of the bendable segment; or, the ultrasonic transducer is disposed on the inner surface of the bendable segment facing the inner tube.

[0014] In some embodiments, the bendable segment is disposed proximate to the first fixed segment.

[0015] In some embodiments, the bendable segment is directly connected to the first fixed segment.

[0016] In some embodiments, the outer tube also includes a second fixed segment, and a bendable positioning segment connected between the second fixed segment and the first fixed segment; the catheter also includes a sliding member axially slidably arranged on the inner side of the inner tube, the sliding member is connected to the second fixed segment, and the second fixed segment is driven to move toward the first fixed segment by the sliding member, and the positioning segment bends when the second fixed segment moves toward the first fixed segment to form a curved shape that bulges outward from both ends to the middle as a whole.

[0017] In some embodiments, the sliding member includes a sliding tube and a sliding shaft, the sliding tube is located on the inner side of the positioning section, one end of the sliding tube is inserted into the inner tube and fixedly connected to one end of the sliding shaft, and the other end of the sliding tube extends out of the inner tube and fixedly connected to the second fixed section.

[0018] In some embodiments, the ultrasonic transducer is a focused ultrasonic transducer or an unfocused ultrasonic transducer.

[0019] In some embodiments, each of the multiple ultrasonic transducers of the ultrasonic transducer array transmits ultrasonic waves focused on a point or an area.

[0020] The interventional variable-focus ultrasound catheter of the embodiment of the present application can not only enhance the local intensity of ultrasound and improve the local therapeutic effect of ultrasound, but also expand the range of action of ultrasound in the circumferential and radial directions, significantly improving the therapeutic range and efficiency of ultrasound. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following briefly introduces the drawings required for use in the embodiments or the prior art description. Obviously, the drawings described below are only some embodiments recorded in this specification. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. In the drawings:

[0022] Figure 1is a cross-sectional view of an interventional variable-focus ultrasound catheter in an original state according to an embodiment of the present application;

[0023] Figure 2 is a cross-sectional view of an interventional variable-focus ultrasound catheter in a working state according to an embodiment of the present application;

[0024] Figure 3 is a cross-sectional view of an invasive variable-focus ultrasound catheter in a working state in a blood vessel according to an embodiment of the present application;

[0025] Figure 4 is a schematic diagram of a three-dimensional structure in which a bendable section is in a straightened state in another embodiment of the present application;

[0026] Figure 5 is a schematic diagram of a three-dimensional structure in which a bendable section is in a bent state in another embodiment of the present application;

[0027] Figure 6 It is a schematic diagram of the three-dimensional structure of a bendable section in a bent state in another embodiment of the present application. DETAILED DESCRIPTION

[0028] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below in conjunction with the drawings in the embodiments of this specification. Obviously, the described embodiments are only part of the embodiments of this specification, not all of the embodiments. Based on the embodiments in this specification, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of this specification.

[0029] In the embodiments of the present application, the terms "first", "second", etc. are used to distinguish different elements from the title, but do not represent the spatial arrangement or time sequence of these elements, etc., and these elements should not be limited by these terms. The term "and / or" includes any one and all combinations of one or more of the terms listed in association. The terms "comprising", "including", "having", etc. refer to the existence of the stated features, elements, components or components, but do not exclude the existence or addition of one or more other features, elements, components or components.

[0030] In the embodiments of the present application, the singular forms "a", "the", etc. may include plural forms and should be broadly understood as "a kind" or "a type" rather than being limited to the meaning of "one"; in addition, the term "said" should be understood to include both singular and plural forms, unless the context clearly indicates otherwise; in addition, the term "according to" should be understood as "at least partially based on...", and the term "based on" should be understood as "at least partially based on...", unless the context clearly indicates otherwise; in addition, the term "plurality" means two or more, unless otherwise specified.

[0031] The present application provides an interventional variable-focus ultrasound catheter for ultrasound treatment in human blood vessels. The interventional variable-focus ultrasound catheter of the present application includes an inner tube, an outer tube, and a plurality of ultrasonic transducer arrays. The outer tube is sleeved on the outer side of the inner tube. The outer tube includes a first fixed section fixed relative to the inner tube, and a slidable section that can slide relative to the inner tube in an axial direction, the slidable section includes a bendable section, and the bendable section bends to form a curved shape that is concave inward from both ends to the middle as a whole when the slidable section slides toward the first fixed section.

[0032] Multiple ultrasonic transducer arrays are all arranged in the bendable section and spaced apart in the circumferential direction. Each ultrasonic transducer array includes multiple ultrasonic transducers spaced apart in the axial direction. The ultrasonic waves generated by the multiple ultrasonic transducers of each ultrasonic transducer array are focused when the bendable section is in a bent shape. The change in the bending amplitude of the bendable section changes the focal length of the ultrasonic wave. The focusing positions of the ultrasonic waves emitted by the ultrasonic transducers of the multiple ultrasonic transducer arrays are distributed in the entire circumferential range of the outer side of the outer tube.

[0033] The interventional variable-focus ultrasound catheter of the present application can not only enhance the local intensity of ultrasound and improve the local therapeutic effect of ultrasound, but also expand the range of action of ultrasound in the circumferential and radial directions, significantly improving the therapeutic range and efficiency of ultrasound.

[0034] Specifically, the present application focuses ultrasound waves by setting a bendable segment and setting a plurality of ultrasonic transducers arranged at intervals along the axial direction on the bendable segment, thereby enhancing the local intensity of ultrasound waves, and by changing the number of ultrasonic transducers in each ultrasonic transducer array, the focusing intensity of ultrasound waves can be changed.

[0035] In addition, in the circumferential direction, the present application sets up multiple ultrasonic transducer arrays arranged at intervals along the circumferential direction, so that the focusing position of the ultrasonic wave is distributed in the entire circumferential range outside the outer tube, thereby improving the focusing range of the ultrasonic wave in the circumferential direction, achieving the effect of treating the tissue to be treated (such as nerves) around the blood vessels, making the treatment range of the ultrasonic wave in the circumferential direction larger and the treatment efficiency higher.

[0036] In the radial direction, the present application sets a slidable section with a bendable section. By adjusting the sliding distance of the slidable section, the bending amplitude of the bendable section can be adjusted, thereby adjusting the focal length of the ultrasound wave, that is, adjusting the focusing position of the ultrasound wave in the radial direction, thereby improving the focusing range of the ultrasound wave in the radial direction, achieving the effect of treating different depths of the tissue to be treated (such as nerves), making the treatment range of the ultrasound wave in the radial direction larger and the treatment efficiency higher.

[0037] It is worth mentioning that the continuous sliding of the slidable segment allows the bending amplitude of the bendable segment to be continuously adjusted, so that the focal length of the ultrasound wave can be continuously and steplessly adjusted in the radial direction, thereby achieving the effect of treating all different depths of the tissue to be treated (such as nerves).

[0038] The present application controls the ultrasonic focusing of multiple ultrasonic transducer arrays by sliding an outer tube, providing a new method of controlling ultrasonic focusing, which is very convenient to operate. There is no need to bend the entire interventional variable-focus ultrasonic catheter, and the position of the central axis of the interventional variable-focus ultrasonic catheter in the blood vessel is not changed. The central axis of the interventional variable-focus ultrasonic catheter is always roughly parallel to the blood vessel. In addition, the present application can simultaneously control the ultrasonic focusing of multiple ultrasonic transducer arrays by sliding an outer tube. The range of action of the ultrasonic wave is the entire circumferential range (the entire annular area) of the outside of the interventional variable-focus ultrasonic catheter, and there is no need to precisely control the position of a single focus point.

[0039] The interventional variable-focus ultrasound catheter of the present application can be inserted into the blood vessels corresponding to the nerves to be ablated, and ablate the nerves to be ablated around the blood vessels to achieve the therapeutic purpose of ultrasound ablation.

[0040] The implementation of the embodiments of the present application will be described below with reference to the accompanying drawings.

[0041] like Figure 1 As shown, the interventional variable-focus ultrasound catheter 100 of the present application is an elongated structure as a whole, so as to be able to intervene in human blood vessels. The interventional variable-focus ultrasound catheter 100 has a proximal end and a distal end, the distal end is the end away from the operator, and the distal end can be inserted into the patient's blood vessel; the proximal end is the end close to the operator, and the proximal end can be located outside the patient's body, and of course, can also be located inside the patient's body.

[0042] like Figure 1 As shown, the interventional variable-focus ultrasound catheter 100 of the present application includes an outer tube 1 and an inner tube 2. Both the inner tube 2 and the outer tube 1 are slender tubular structures extending along an axial direction. The axial direction mentioned herein may refer to the direction in which the inner tube 2 or the outer tube 1 extends, the circumferential direction mentioned herein may refer to the circumferential direction of the inner tube 2 or the outer tube 1, and the radial direction mentioned herein may refer to the radial direction of the inner tube 2 or the outer tube 1, which are explained together here.

[0043] The material of the inner tube 2 and the outer tube 1 can be PVC, PEBAX, PE, TPU, Teflon, polyimide and other commonly used interventional catheter materials. The inner tube 2 can be a one-piece structure or a split structure formed by connecting multiple tubes, which is not limited in this application. The outer tube 1 can be a one-piece structure or a split structure formed by connecting multiple tubes, which is not limited in this application.

[0044] like Figure 1 As shown, the outer tube 1 is sleeved on the outer side of the inner tube 2, and the outer tube 1 and the inner tube 2 can be clearance-fitted. The outer tube 1 includes a first fixed section 11 and a slidable section 12, and the first fixed section 11 is fixedly connected to the inner tube 2, so the first fixed section 11 is fixed relative to the inner tube 2, and the two cannot move relative to each other, for example, the first fixed section 11 and the inner tube 2 are fixed by welding.

[0045] The slidable section 12 is only sleeved on the outside of the inner tube 2 without being connected to the inner tube 2. The two can be clearance-fitted, and the two can slide relative to each other in the axial direction. The power to drive the two to slide relative to each other can be applied by the operator at the proximal end of the ultrasonic catheter, or by a driving device, and the present application does not limit this. The power can be applied to the outer tube 1 or to the inner tube 2, as long as relative sliding can occur between the two, and the present application does not limit this. When the power is applied to the outer tube 1, the power can be a thrust that pushes the outer tube 1 toward the distal end of the interventional variable-focus ultrasonic catheter 100; when the power is applied to the inner tube 2, the power can be a pulling force that pulls the inner tube 2 toward the proximal end of the interventional variable-focus ultrasonic catheter 100.

[0046] Unless otherwise specified, the sliding of the slidable section 12 mentioned in this article refers to the sliding of the slidable section 12 relative to the inner tube 2 in the axial direction, which is explained here together.

[0047] like Figure 1 and Figure 2 As shown, the slidable section 12 of the outer tube 1 includes a bendable section 121. When the slidable section 12 of the outer tube 1 slides toward the first fixed section 11, the bendable section 121 is squeezed and bends, so as to be deformed from a straight tubular shape to a curved shape that is concave inward from both ends to the middle as a whole (such as Figure 2 As shown), the curved shape is roughly an inwardly concave arc shape, and the arc shape refers to the overall contour being roughly a concave arc shape, and is not limited to a smooth concave arc shape, and can be a smooth or uneven concave arc shape.

[0048] like Figure 1 and 2 As shown, a plurality of ultrasonic transducer arrays 3 are arranged at intervals along the circumferential direction on the bendable section 121 of the outer tube 1, and each ultrasonic transducer array 3 includes a plurality of ultrasonic transducers 31 arranged at intervals along the axial direction. Figure 2 As shown in FIG. 1 , when the bendable section 121 of the outer tube 1 is in a curved shape that is concave inward from both ends to the middle, the ultrasonic waves 200 generated by the multiple ultrasonic transducers 31 of each ultrasonic transducer array 3 are focused. By adjusting the bending amplitude of the bendable section 121, the focal length of the focused ultrasonic waves 200 can be adjusted, thereby changing the radial direction (such as the radial direction) of the ultrasonic waves 200. Figure 2The focusing positions 300 of the ultrasonic waves 200 generated by the ultrasonic transducers 31 of the plurality of ultrasonic transducer arrays 3 are distributed in the entire circumferential range outside the outer tube 1 to expand the range of action of the focused ultrasonic waves 200 in the radial direction.

[0049] Specifically, the interventional variable-focus ultrasound catheter 100 has an initial state (eg Figure 1 as shown) and working status (as shown Figure 2 The original state refers to the state of the interventional variable-focus ultrasound catheter 100 when the entire outer tube 1 is straightened, and the working state refers to the state of the interventional variable-focus ultrasound catheter 100 when the bendable section 121 of the outer tube 1 is bent. The interventional variable-focus ultrasound catheter 100 is inserted into and withdrawn from a blood vessel in the original state. The overall outer diameter of the interventional variable-focus ultrasound catheter 100 in the original state is small, and it can be easily inserted into or withdrawn from a blood vessel without damaging the blood vessel wall.

[0050] When using, Figure 2 As shown, when the interventional variable-focus ultrasound catheter 100 is inserted into the blood vessel 400 in its original state and the bendable segment 121 reaches the nerve to be ablated, the outer tube 1 can be pushed toward the distal end of the interventional variable-focus ultrasound catheter 100 to make the slidable segment 12 of the outer tube 1 slide toward the first fixed segment 11. The sliding of the slidable segment 12 causes the bendable segment 121 to bend. At this time, the interventional variable-focus ultrasound catheter 100 is in a working state; as the sliding distance of the slidable segment 12 increases, the bending amplitude of the bendable segment 121 gradually increases, and the focal length of the ultrasonic transducer 31 on the bendable segment 121 gradually decreases, so that the focused ultrasound can act on different depth positions of the nerve to be ablated, thereby expanding the ablation range in the radial direction. During the treatment process, if it is necessary to repeatedly ablate different depths of the nerve to be ablated, the outer tube 1 can be repeatedly pushed forward and pulled backward to make the outer tube 1 slide back and forth. The reciprocating sliding of the outer tube 1 causes the bending amplitude of the bendable section 121 to increase and decrease repeatedly, and the focal length of the ultrasonic transducer 31 on the bendable section 121 to increase and decrease repeatedly, so that the focused ultrasonic waves repeatedly act on different depths of the nerve to be ablated. After the treatment is completed, the outer tube 1 can be pulled toward the proximal end of the interventional variable-focus ultrasound catheter 100 to flatten the outer tube 1. At this time, the interventional variable-focus ultrasound catheter 100 returns to its original state and can be easily withdrawn from the blood vessel.

[0051] To facilitate the bending of the bendable segment 121 , the bendable segment 121 may be configured as a discontinuous structure in the circumferential direction. For example, an opening may be provided on the bendable segment 121 to separate the bendable segment 121 into a discontinuous structure in the circumferential direction.

[0052] exist Figures 4 to 6 In the example of , the bendable section 121 is provided with openings 122 spaced apart in the circumferential direction to separate the bendable section 121 into a plurality of bendable strips 123, the plurality of bendable strips 123 are at least partially spaced apart in the circumferential direction, each bendable strip 123 extends in the axial direction, each ultrasonic transducer array 3 is respectively provided on a bendable strip 123, and a plurality of ultrasonic transducers 31 of each ultrasonic transducer array 3 are spaced apart in the axial direction on the bendable strip 123, therefore, when the slidable section 12 of the outer tube 1 slides toward the first fixed section 11, the plurality of bendable strips 123 are squeezed and bend respectively and simultaneously, from a straight strip (such as Figure 4 As shown in the figure, the shape of the arc is deformed into a concave arc shape that is concave from both ends to the middle (as shown in the figure). Figure 5 shown).

[0053] In order to enable the bendable section 121 to bend into a curved shape that is concave inward from both ends to the middle as a whole, the following two embodiments that can be implemented separately or in combination can be adopted.

[0054] In a first optional embodiment, if Figure 4 and Figure 5 As shown, the middle parts of the multiple flexible bands 123 are connected in sequence in the circumferential direction to form a first connecting ring 124, that is, the multiple flexible bands 123 are partially spaced apart in the circumferential direction, that is to say, the middle parts of the multiple flexible bands 123 are not spaced apart, but are connected in sequence to form the first connecting ring 124, and the rest of the multiple flexible bands 123 are spaced apart.

[0055] The first connecting ring 124 limits the bending of the middle part of each flexible band 123 when the flexible section 121 is bent. The first connecting ring 124 can be an annular structure that continuously extends along the circumferential direction. Since the first connecting ring 124 limits the bending deformation of the middle part of the flexible section 121, the bending of the two end parts of the flexible section 121 located on both sides of the middle part will make the flexible section 121 present a curved shape that is concave inward from the two ends to the middle.

[0056] Alternatively, if Figure 4 and Figure 5 As shown, on the outer surface of each bendable belt 123 facing away from the inner tube 2, a plurality of linear folding grooves 125 are provided to cause the bendable section 121 to be bent into a curved shape that is concave inward from both ends to the middle as a whole. The plurality of folding grooves 125 are arranged at intervals along the length direction of the bendable belt 123, and each folding groove 125 extends along the width direction of the bendable belt 123. Since the wall thickness of the folding grooves 125 is thinner than that of other parts of the bendable section 121, the bendable belt 123 will bend preferentially at each folding groove 125, so the provision of the folding grooves 125 can cause the bendable section 121 to bend.

[0057] The setting position of the folding groove 125 can be determined according to the required bending shape. For example, a folding groove 125 is provided at both ends of the first connecting ring 124, and a folding groove 125 is provided at both ends of each flexible band 123. At least one folding groove 125 can be provided in the part between the two ends of each flexible band 123.

[0058] Preferably, if Figure 4 and Figure 5 As shown, the folding groove 125 on the flexible band 123 is symmetrically distributed relative to the first connecting ring 124, and the ultrasonic transducers 31 on the flexible band 123 are symmetrically distributed relative to the first connecting ring 124. Therefore, when the flexible band 123 is bent along the folding groove 125, the ultrasonic transducers 31 located on both sides of the first connecting ring 124 also always remain symmetrical, so that the ultrasonic wave of the ultrasonic transducer 31 can be accurately focused.

[0059] Although the configuration of the folding groove 125 makes the bendable belt 123 not be a smooth arc, Figure 5 The zigzag arc shown is composed of multiple short planes inclined in sequence, but the flexible belt 123 as a whole is in a curved shape that is concave inward from both ends to the middle, so that the ultrasonic waves generated by the ultrasonic transducer 31 located on the same flexible belt 123 can be focused.

[0060] exist Figure 4 and Figure 5 In the example, each ultrasonic transducer array 3 includes four ultrasonic transducers 31, and the four ultrasonic transducers 31 are symmetrically distributed on both sides of the first connecting ring 124, wherein two ultrasonic transducers 31 are arranged on the bendable belt 123 on the left side of the first connecting ring 124 (referred to as the left side portion of the bendable belt), and the other two ultrasonic transducers 31 are arranged on the bendable belt 123 on the right side of the first connecting ring 124 (referred to as the right side portion of the bendable belt). Correspondingly, six folding grooves 125 are arranged on each bendable belt 123, and the six folding grooves 125 are symmetrically distributed on the left and right sides of the first connecting ring 124, wherein three folding grooves 125 are arranged on the left side portion of the bendable belt, and the other three folding grooves 125 are arranged on the right side portion of the bendable belt 123.

[0061] Taking the three folding grooves 125 on the left side of the bendable belt as an example, the first folding groove 125 is located between the left end of the left side of the bendable belt and the body of the slidable section 12, the second folding groove 125 is located between the right end of the left side of the bendable belt and the left end of the first connecting ring 124, and the third folding groove 125 is located at the middle left side of the left side of the bendable belt, so as to divide the left side of the bendable belt into a smaller area 1231 on the left side and a larger area 1232 on the right side. The larger area 1232 is used to install two ultrasonic transducers 31, and the smaller area 1231 may not be installed with the ultrasonic transducer 31, but serves as the part with the largest inclination angle of the bendable section 121, such as Figure 5 As shown, when the bendable section 121 bends, the smaller area 1231 is inclined outward relative to the inner tube 2 at a larger inclination angle than the larger area 1232. Under the support of the smaller area 1231, the larger area 1232 and the ultrasonic transducer 31 thereon are in an inclined state, so that the entire bendable section 121 is in a curved shape that is concave inward from both ends to the middle as a whole.

[0062] Figure 4 and Figure 5 It is shown for example only that the bendable section 121 includes four bendable bands 123, each of which is provided with four ultrasonic transducers 31 and six folding grooves 125. However, this is not a limitation to the present application, and the number of bendable bands 123, the number of ultrasonic transducers 31 and the number of folding grooves 125 can be determined according to actual needs.

[0063] In a second alternative embodiment, if Figure 1 and Figure 2 As shown, each bendable belt 123 is provided with a metal foil 126 that causes the bendable segment 121 to bend into a curved shape that is concave inward from both ends to the middle as a whole. The metal foil 126 has a pre-deformed shape that is the same as the curved shape, that is, the metal foil 126 has a pre-deformed shape that is concave inward from both ends to the middle as a whole. Therefore, the metal foil 126 can assist the bendable belt 123 to bend into the curved shape. Figure 1 and Figure 2 In the example of FIG. 1 , the pre-deformed shape of the metal foil 126 is a concave arc shape.

[0064] Optionally, the metal foil 126 is electrically connected to the ultrasonic transducer 31 as an electrode of the ultrasonic transducer 31, so the metal foil 126 can not only assist the bending of the flexible band 123, but also can be used as an electrode of the ultrasonic transducer 31 to transmit a driving signal thereto, thereby eliminating the need for additional electrodes and simplifying the structure of the ultrasonic catheter. The metal foil 126 can be disposed on the outer surface of the flexible section 121 facing away from the inner tube 2, or disposed in the side wall of the flexible section 121, or disposed on the inner surface of the flexible section 121 facing the inner tube 2. The material of the metal foil 126 can be a conductive metal such as copper, iron, or gold.

[0065] Of course, instead of using the metal foil 126 as the electrode of the ultrasonic transducer 31, an additional electrode may be provided, and the metal or non-metal sheet having the pre-deformed shape may be fixed on the electrode of the ultrasonic transducer 31 by gluing or the like. In this case, the metal or non-metal sheet only serves to assist the bending of the flexible band 123.

[0066] Optionally, the outer tube 1 can be manufactured by a flexible printed circuit board process, which can be used to conveniently manufacture electrodes and wires for the ultrasonic transducer 31 in the outer tube 1 .

[0067] The first and second embodiments described above can be implemented separately or in combination, that is, the first connecting ring 124 and the metal foil 126 are provided at the same time. The combined implementation can better assist the bending of the flexible belt 123.

[0068] Figure 6 Another embodiment of the bendable belt 123 in the present application is shown. Figure 4 and Figure 5 The difference of the illustrated embodiment is that the plurality of flexible bands 123 are completely spaced apart in the circumferential direction without being connected to form a Figure 4 and Figure 5 The first connecting ring 124 is shown.

[0069] In order to facilitate the bending of the bendable section 121, the bendable section 121 may be arranged close to the first fixed section 11. Figures 1 to 5 As shown, the bendable segment 121 is directly connected to the first fixed segment 11, that is, the bendable segment 121 is at the end of the slidable segment 12 and is directly connected to the first fixed segment 11 as an anchor point. Therefore, the force driving the slidable segment 12 to slide is ultimately concentrated on the bendable segment 121, causing the bendable segment 121 to bend quickly.

[0070] exist Figures 1 to 6 In the example of FIG. 1 , the ultrasonic transducer 31 is installed on the outer surface of the bendable section 121 facing away from the inner tube 2, which is not only convenient for installation but also conducive to the bending of the bendable section 121. In order to prevent the ultrasonic transducer 31 from scratching the inner wall of the blood vessel, a coating layer 6 (such as Figures 1 to 3 As shown in FIG. 1 , the coating layer 6 completely covers the ultrasonic transducer array 3, and its smooth outer surface facilitates the interventional variable-focus ultrasonic catheter 100 to smoothly and safely intervene in or withdraw from a blood vessel. However, the present application is not limited thereto, and the ultrasonic transducer 31 may also be embedded in the side wall of the bendable section 121, or installed on the inner surface of the bendable section 121 facing the inner tube 2.

[0071] The ultrasonic transducer 31 may be made of piezoelectric materials such as PZT5 and PZT8. Each ultrasonic transducer 31 may have one or more resonant frequencies. The frequency range of the ultrasonic wave generated by each ultrasonic transducer 31 may be 20 kHz to 20 MHz.

[0072] The shape of each ultrasonic transducer 31 can be a regular square or a curved sheet. The curved ultrasonic transducer 31 can better fit the curved outer surface of the outer catheter.

[0073] Optionally, each ultrasonic transducer 31 in the embodiment of the present application may be a focused ultrasonic transducer, and accordingly, the ultrasonic waves generated by the multiple ultrasonic transducers 31 of each ultrasonic transducer array 3 are focused on one point, so that a very high sound intensity can be obtained at the focus.

[0074] Optionally, each ultrasonic transducer 31 in the embodiment of the present application can be a non-focused ultrasonic transducer. Correspondingly, the ultrasonic waves generated by the multiple ultrasonic transducers 31 of each ultrasonic transducer array 3 are focused on an area, which means a focusing range that is larger than the focal area, so the ultrasonic action range of the focusing area is larger.

[0075] Optionally, the ultrasonic array of the embodiment of the present application includes both focused ultrasonic transducers and unfocused ultrasonic transducers. For example, the ultrasonic transducers 31 of some ultrasonic transducer arrays 3 are focused ultrasonic transducers, and the ultrasonic transducers 31 of other ultrasonic transducer arrays 3 are focused ultrasonic transducers, so that the focal point and the focal area can be obtained at the same time.

[0076] exist Figures 1 to 3 In the example, the outer tube 1 also includes a second fixed segment 13, and a bendable positioning segment 14 connected between the second fixed segment 13 and the first fixed segment 11; the interventional variable-focus ultrasound catheter 100 also includes a slidable member 4 axially slidably arranged on the inner side of the inner tube 2, the slidable member 4 is connected to the second fixed segment 13, and the second fixed segment 13 is driven to move toward the first fixed segment 11 by the slidable member 4. When the second fixed segment 13 moves toward the first fixed segment 11, the positioning segment 14 bends into a curved shape that bulges outward from both ends to the middle as a whole. The curved shape of the positioning segment 14 can be a convex arc.

[0077] The outward protrusion of the positioning section 14 is used to contact the inner wall of the blood vessel 400 (eg Figure 3 As shown), the interventional variable-focus ultrasound catheter 100 is positioned at the center of the blood vessel 400, thereby improving the circumferential uniformity and accuracy of ultrasound treatment.

[0078] By adjusting the distance that the second fixed section 13 slides toward the first fixed section 11, the curvature of the positioning section 14 can be adjusted, thereby changing the distance that the positioning section 14 protrudes outward to adapt to blood vessels of different diameters, and the interventional variable-focus ultrasound catheter 100 can be centrally positioned in blood vessels of different diameters.

[0079] When the invasive variable-focus ultrasound catheter 100 is in the original state, the positioning section 14 and the bendable section 121 of the outer tube 1 are both in the straight state. When the invasive variable-focus ultrasound catheter 100 is in the working state, the positioning section 14 and the bendable section 121 of the outer tube 1 are both in the bent state.

[0080] In this embodiment, the function of the slidable member 4 is to transmit power. The power for driving the second fixed segment 13 to move toward the first fixed segment 11 can be applied to the slidable member 4 at the proximal end of the interventional variable-focus ultrasound catheter 100. For example, the operator pulls the slidable member 4 toward the proximal end so that the slidable member 4 drives the second fixed segment 13 to move toward the first fixed segment 11. Of course, the slidable member 4 can also be pulled by a driving device (such as a linear driving device) to achieve automatic control.

[0081] In order to facilitate the bending of the positioning segment 14 , the positioning segment 14 may be configured as a discontinuous structure in the circumferential direction. For example, an opening may be provided on the positioning segment 14 to separate the positioning segment 14 into a discontinuous structure in the circumferential direction.

[0082] Exemplarily, the positioning segment 14 is provided with a plurality of openings spaced apart along the circumferential direction to separate the positioning segment 14 into a plurality of bendable strips spaced apart along the circumferential direction. Therefore, when the second fixed segment 13 moves toward the first fixed segment 11, the plurality of bendable strips are squeezed and bent separately and simultaneously, from a straight straight strip to form a convex arc that protrudes outward from both ends to the middle as a whole.

[0083] In order to cause the positioning segment 14 to bend into a curved shape that bulges outward from both ends to the middle as a whole, folding grooves 125 may be provided at both ends of the positioning segment 14. Since the wall thickness of the folding grooves 125 is thinner than other parts of the positioning segment 14, the positioning segment 14 will preferentially bend from these two folding grooves 125, thereby being easily bent into an arc shape that bulges outward.

[0084] For example, Figures 1 to 3 As shown, the sliding member 4 includes a sliding tube 41 and a sliding shaft 42. The sliding tube 41 is located on the inner side of the positioning section 14. One end of the sliding tube 41 is inserted into the inner tube 2 and fixedly connected to one end of the sliding shaft 42. The other end of the sliding tube 41 extends out of the inner tube 2 and is fixedly connected to the second fixed section 13.

[0085] Specifically, Figures 1 to 3 As shown, the sliding tube 41 is inserted into the inner tube 2, and the sliding tube 41 and the inner tube 2 can slide relative to each other, for example, the two are clearance-matched, and the inner tube 2 can guide the sliding tube 41 to slide smoothly in the axial direction. The other end of the sliding tube 41 has a convex ring structure 411 protruding radially outward, and the outer wall of the convex ring structure 411 is fixedly connected to the inner wall of the second fixed section 13, for example, the two can be fixedly connected by welding, and an annular gap 5 is formed between the sliding tube 41 and the positioning tube. In the axial direction, the annular gap 5 is located between the convex ring structure 411 and the left end face 21 of the inner tube 2, and the annular gap 5 provides a sliding space for the sliding tube 41. The convex ring structure 411 and the end face of the inner tube 2 serve as a limiting structure to limit the sliding limit position of the sliding tube 41.

[0086] like Figure 1 As shown, the two folded grooves 125 on the outer surface of the positioning segment 14 are respectively opposite to the right end surface 412 of the convex ring structure 411 and the left end surface 21 of the inner tube 2. Therefore, the entire part of the positioning segment 14 corresponding to the annular gap 5 can protrude outward in a convex arc shape.

[0087] One end of the sliding shaft 42 is fixedly connected to the end of the sliding tube 41 extending into the inner tube 2, and the other end of the sliding shaft 42 can extend to the proximal end of the interventional variable-focus ultrasound catheter 100. Therefore, the operator or the driving device can pull the other end of the sliding shaft 42 at the proximal end to drive the second fixed section 13 of the outer tube 1 toward the first fixed section 11 through the sliding shaft 42 and the sliding tube 41, which is very convenient to operate. When the pulling of the sliding shaft 42 is canceled, the positioning section 14 can automatically return to the straight state by its own restoring force.

[0088] The above description is only an embodiment of the present specification and is not intended to limit the present specification. For those skilled in the art, the present specification may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present specification shall be included in the scope of the claims of the present specification.

Claims

1. An interventional variable-focus ultrasound catheter, characterized in that: include: Inner tube; an outer tube, which is sleeved outside the inner tube and includes a first fixed section fixed relative to the inner tube, and a slidable section that can slide relative to the inner tube in an axial direction, wherein the slidable section includes a bendable section, and the bendable section is bent into a curved shape that is concave inward from both ends to the middle as a whole when the slidable section slides toward the first fixed section; A plurality of ultrasonic transducer arrays are arranged in the bendable section and spaced apart in the circumferential direction, each ultrasonic transducer array comprises a plurality of ultrasonic transducers spaced apart in the axial direction, the ultrasonic waves generated by the plurality of ultrasonic transducers of each ultrasonic transducer array are focused when the bendable section is in the bent shape, the change in the bending amplitude of the bendable section changes the focal length of the ultrasonic waves, and the focusing positions of the ultrasonic waves emitted by the ultrasonic transducers of the plurality of ultrasonic transducer arrays are distributed within the entire circumferential range of the outer side of the outer tube.

2. The invasive variable-focus ultrasound catheter according to claim 1, characterized in that: The bendable section comprises a plurality of bendable bands, the plurality of bendable bands are at least partially spaced apart in the circumferential direction, each of the bendable bands extends along the axial direction, each of the ultrasonic transducer arrays is respectively arranged on one of the bendable bands, and the plurality of ultrasonic transducers of each of the ultrasonic transducer arrays are spaced apart along the axial direction on the bendable band.

3. The invasive variable-focus ultrasound catheter according to claim 2, characterized in that: The middle portions of the plurality of bendable bands are sequentially connected in a circumferential direction to form a first connecting ring, and the first connecting ring limits the bending of the middle portion of each bendable band when the bendable segment is bent.

4. The invasive variable-focus ultrasound catheter according to claim 2, characterized in that: A plurality of folding grooves for causing the bendable section to bend into the curved shape are arranged on the outer surface of each bendable belt facing away from the inner tube. The plurality of folding grooves are arranged at intervals along the length direction of the bendable belt, and each folding groove extends along the width direction of the bendable belt.

5. The invasive variable-focus ultrasound catheter according to any one of claims 2 to 4, characterized in that: Each of the bendable strips is provided with a metal foil for causing the bendable segment to bend into the bent shape, and the metal foil has a pre-deformed shape that is the same as the bent shape.

6. The invasive variable-focus ultrasound catheter according to claim 5, characterized in that: The metal foil serves as an electrode of the ultrasonic transducer and is electrically connected to the ultrasonic transducer.

7. The invasive variable-focus ultrasound catheter according to claim 5, characterized in that: The metal foil is arranged on the outer surface of the bendable section facing away from the inner tube; or, The metal foil is embedded in the side wall of the bendable section; or, The metal foil is disposed on an inner surface of the bendable section facing the inner tube.

8. The invasive variable-focus ultrasound catheter according to claim 1, characterized in that: The ultrasonic transducer is disposed on the outer surface of the bendable section facing away from the inner tube; or, The ultrasonic transducer is embedded in the side wall of the bendable section; or, The ultrasonic transducer is disposed on the inner surface of the bendable section facing the inner tube.

9. The invasive variable-focus ultrasound catheter according to claim 1, characterized in that: The bendable section is disposed close to the first fixed section.

10. The invasive variable-focus ultrasound catheter according to claim 9, characterized in that: The bendable section is directly connected to the first fixed section.

11. The invasive variable-focus ultrasound catheter according to claim 1, characterized in that: The outer tube further comprises a second fixing section, and a bendable positioning section connected between the second fixing section and the first fixing section; The catheter also includes a slidable member axially slidably arranged on the inner side of the inner tube, the slidable member is connected to the second fixed section, and the second fixed section is driven to move toward the first fixed section by the slidable member. When the second fixed section moves toward the first fixed section, the positioning section bends to form a curved shape that bulges outward from both ends to the middle as a whole.

12. The invasive variable-focus ultrasound catheter according to claim 11, characterized in that: The slidable member includes a sliding tube and a sliding shaft. The sliding tube is located on the inner side of the positioning section. One end of the sliding tube is inserted into the inner tube and fixedly connected to one end of the sliding shaft. The other end of the sliding tube extends out of the inner tube and fixedly connected to the second fixed section.

13. The invasive variable-focus ultrasound catheter according to claim 1, characterized in that: The ultrasonic transducer is a focused ultrasonic transducer or a non-focused ultrasonic transducer.

14. The invasive variable-focus ultrasound catheter according to claim 13, characterized in that: The ultrasonic waves emitted by the multiple ultrasonic transducers of each ultrasonic transducer array are focused on a point or an area.

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