Medical device for ultrasound-assisted drug delivery

Abstract

This invention discloses systems and methods for treating vascular regions. An example system for treating a vascular region may include an elongated catheter shaft having a distal region. A central lumen may be formed in the elongated catheter shaft. A treatment core may be disposed within the central lumen. The treatment core may include a plurality of ultrasonic transducers disposed near the distal region of the elongated catheter shaft. The catheter shaft may include a fluid delivery chamber disposed near the central lumen, the fluid delivery chamber being configured to deliver microbubbles and / or fluid therein. At least a portion of the fluid delivery chamber may be arranged relative to the central lumen such that the microbubbles and / or fluid disposed within the fluid delivery chamber are protected from ultrasonic energy emitted from the plurality of ultrasonic transducers.

Description

Cross-references to related applications

[0001] This application claims the benefit of priority to U.S. Provisional Application No. 63 / 547,197, filed November 3, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0002] This invention relates to medical devices and methods for manufacturing medical devices. More particularly, this invention relates to medical devices for ultrasound-assisted drug delivery. Background Technology

[0003] Various intravascular medical devices have been developed for medical applications, such as intravascular use. Some of these devices include guidewires, catheters, etc. These devices are manufactured using a wide variety of different methods and can be used according to a wide variety of methods. Each of these medical devices and methods is known to have certain advantages and disadvantages. There is currently a need to provide alternative medical devices and alternative methods for manufacturing and using these medical devices. Summary of the Invention

[0004] This invention provides designs, materials, manufacturing methods, and alternatives for using medical devices. The invention discloses a system for treating a vascular region. The system includes: an elongated catheter shaft having a distal region; wherein a central lumen is formed within the elongated catheter shaft; a treatment core disposed within the central lumen, the treatment core including a plurality of ultrasonic transducers disposed near the distal region of the elongated catheter shaft; wherein the catheter shaft includes a fluid delivery chamber disposed near the central lumen, the fluid delivery chamber being configured to deliver microbubbles and / or fluid therein; and wherein at least a portion of the fluid delivery chamber is arranged relative to the central lumen such that the microbubbles and / or fluid disposed within the fluid delivery chamber are protected from ultrasonic energy emitted from the plurality of ultrasonic transducers.

[0005] Alternatively or additionally, in any of the above embodiments, the fluid delivery cavity is formed in the conduit shaft.

[0006] Alternatively or additionally, in any of the above embodiments, each of the plurality of ultrasonic transducers is configured to emit ultrasonic energy in a first direction, wherein the fluid delivery cavity is offset from the first direction.

[0007] Alternatively or additionally, in any of the above embodiments, each of the plurality of ultrasonic transducers is configured to emit ultrasonic energy in a first direction and a second direction, wherein the fluid delivery cavity is offset from the first direction and offset from the second direction.

[0008] Alternatively or additionally, in any of the above embodiments, the fluid delivery cavity is formed in the wall of the conduit shaft.

[0009] Alternatively or additionally, in any of the above embodiments, the fluid delivery cavity includes one or more side holes formed therein, the side holes extending through the wall of the conduit shaft.

[0010] Alternatively or additionally, in any of the above embodiments, the fluid delivery cavity is defined by a tubular member disposed near the conduit axis.

[0011] Alternatively or additionally, in any of the above embodiments, the tubular member is configured to protect the microbubbles and / or fluid disposed within the fluid delivery cavity from the ultrasonic energy emitted from a plurality of ultrasonic transducers.

[0012] Alternatively or additionally, in any of the above embodiments, the fluid delivery cavity includes a cavitation.

[0013] Alternatively or additionally in any of the above embodiments, cavitation is configured to protect microbubbles and / or fluid disposed within the fluid delivery cavity from ultrasonic energy emitted from a plurality of ultrasonic transducers.

[0014] Alternatively or additionally, any of the above embodiments may also include one or more additional fluid delivery chambers disposed near the central cavity.

[0015] This invention discloses a system for treating a vascular region. The system includes: an elongated catheter shaft having a distal region; wherein a central lumen is formed within the elongated catheter shaft; an ultrasonic treatment core disposed within the central lumen, the ultrasonic treatment core including a plurality of axially spaced ultrasonic transducers; wherein the catheter shaft includes a plurality of shielded delivery cavities disposed near the central lumen, the plurality of shielded delivery cavities being configured to deliver microbubbles and / or fluid to a target region; and wherein at least a portion of each of the shielded delivery cavities is configured to protect the microbubbles and / or fluid disposed within the shielded delivery cavity from the influence of the plurality of axially spaced ultrasonic transducers.

[0016] Alternatively or additionally, in any of the above embodiments, a shielded delivery cavity is formed in the conduit shaft.

[0017] Alternatively or additionally, in any of the above embodiments, each of the plurality of axially spaced ultrasonic transducers is configured to emit ultrasonic energy in a first direction, wherein the shielded delivery cavity is offset from the first direction.

[0018] Alternatively or additionally, for any of the above embodiments, each of the plurality of axially spaced ultrasonic transducers includes one or more side holes formed therein, the side holes extending through the wall of the conduit shaft.

[0019] Alternatively or additionally, in any of the above embodiments, each of the plurality of axially spaced ultrasonic transducers is defined by a tubular member disposed near the duct axis.

[0020] Alternatively or additionally, in any of the above embodiments, the tubular member is configured to protect the microbubbles and / or fluid disposed within the fluid delivery chamber from ultrasonic energy emitted from a plurality of axially spaced ultrasonic transducers.

[0021] Alternatively or additionally, in any of the above embodiments, each of the shielded delivery cavities includes a cavitation.

[0022] Alternatively or additionally in any of the above embodiments, cavitation is configured to protect microbubbles and / or fluid disposed within a shielded delivery cavity from ultrasonic energy emitted from a plurality of axially spaced ultrasonic transducers.

[0023] This invention discloses a method for delivering a drug to a vascular region. The method includes: advancing a catheter system to a treatment site, the catheter system comprising: an elongated catheter shaft having a distal region; wherein a central lumen is formed within the elongated catheter shaft; a treatment core disposed within the central lumen, the treatment core including a plurality of ultrasonic transducers disposed near the distal region of the elongated catheter shaft; wherein the catheter shaft includes a fluid delivery chamber disposed near the central lumen, the fluid delivery chamber being configured to deliver microbubbles and / or fluid therein; and wherein at least a portion of the fluid delivery chamber is arranged relative to the central lumen such that the microbubbles and / or fluid disposed within the fluid delivery chamber are protected from ultrasonic energy emitted from the plurality of ultrasonic transducers; advancing the treatment core through the central lumen such that the plurality of ultrasonic transducers are disposed near the distal region of the elongated catheter shaft; passing therapeutic fluid through the fluid delivery chamber; and activating at least some of the plurality of ultrasonic transducers.

[0024] The above overview of some embodiments is not intended to describe every disclosed embodiment or implementation of the invention. These embodiments are illustrated more specifically by way of example in the following figures and detailed descriptions. Attached Figure Description

[0025] The invention can be more fully understood by considering the following detailed description taken in conjunction with the accompanying drawings, in which:

[0026] Figure 1 This is a schematic diagram illustrating certain features of an illustrative ultrasound catheter.

[0027] Figure 2 It is along Figure 1 The cross-sectional view taken from line 2-2.

[0028] Figure 3 It is configured to be located in Figure 2A schematic diagram illustrating the slender inner core within the central lumen of the catheter.

[0029] Figure 4 It is along Figure 3 The cross-sectional view taken by line 4-4.

[0030] Figure 5 This is a schematic wiring diagram illustrating a technique for electrically connecting five sets of ultrasonic radiating components to form an ultrasonic assembly.

[0031] Figure 6 This is a schematic wiring diagram that shows an electrical connection. Figure 5 The technology of one group in each group.

[0032] Figure 7A It is contained in Figure 4 The inner core Figure 5 A schematic diagram of the ultrasound component.

[0033] Figure 7B It is along Figure 7A The cross-sectional view taken from line 7B-7B.

[0034] Figure 7C It is along Figure 7A A cross-sectional view taken from line 7C-7C.

[0035] Figure 7D This is a side view of the central wire of the ultrasonic component, twisted into a spiral shape.

[0036] Figure 8 It shows the location at Figure 1 The energy transmission section of the tubular main body Figure 4 The energy transmission section of the inner core.

[0037] Figure 9 A portion of the example system is shown.

[0038] Figure 10 A portion of the example system is shown.

[0039] Figure 11 Through Figure 10 The line 11-11 in the middle is cut off Figure 10 The example system shown is a cross-sectional view.

[0040] Figure 12 A portion of the example system is shown.

[0041] While the invention is adaptable to various modifications and alternatives, its specific details have been shown by way of example in the accompanying drawings and will be described in more detail. However, it should be understood that the invention is not intended to limit its aspects to the specific embodiments described. Rather, it is intended to cover all modifications, equivalents, and alternatives that fall within the spirit and scope of the invention. Detailed Implementation

[0042] For the purposes of the following definitions, unless otherwise specified in the claims of this specification or elsewhere, these definitions shall apply.

[0043] All numerical values ​​herein are assumed to be modified by the term "about," whether or not explicitly stated otherwise. The term "about" generally refers to a range of numbers that a person skilled in the art would consider equivalent to (e.g., having the same function or result) the referenced number. In many cases, the term "about" may include numbers rounded to the nearest significant figure.

[0044] A description of a range of numbers represented by endpoints includes all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0045] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural indicators unless otherwise expressly indicated. As used in this specification and the appended claims, the term “or” is generally used in the sense of including “and / or” unless otherwise expressly indicated.

[0046] It should be noted that references to "one embodiment," "some embodiments," "other embodiments," etc., in this specification indicate that the described embodiments may include one or more specific features, structures, and / or characteristics. However, these descriptions do not necessarily mean that all embodiments include the specific features, structures, and / or characteristics. Furthermore, when a specific feature, structure, and / or characteristic is described in connection with an embodiment, it should be understood that, whether explicitly described or not, such feature, structure, and / or characteristic may also be used in conjunction with other embodiments, unless expressly stated otherwise.

[0047] The following detailed description should be read with reference to the accompanying drawings, in which similar elements in different drawings have the same reference numerals. The drawings, which are not necessarily drawn to scale, depict illustrative embodiments and are not intended to limit the scope of the invention.

[0048] As used herein, the term “ultrasound energy” is used broadly, including in its general sense, and also includes mechanical energy transferred by pressure or compression waves with a frequency greater than about 20 kHz. The frequency of the ultrasound energy wave is between about 500 kHz and about 20 MHz in one example embodiment, between about 1 MHz and about 3 MHz in another example embodiment, about 3 MHz in yet another example embodiment, and about 2 MHz in yet another example embodiment. As used herein, the term “catheter” is used broadly, including in its general sense, and also includes a long, flexible tube configured for insertion into a patient’s body, such as a body part, cavity, catheter, or blood vessel. As used herein, the term “therapeutic compound” is used broadly, including in its general sense, and includes drugs, pharmaceuticals, dissolving compounds, genetic material, and other substances capable of affecting physiological function. Mixtures of such substances are included in this definition of “therapeutic compound.” As used herein, the term “terminal” is used broadly, including in its general sense, and generally also includes a region, such that “proximal” includes “proximal region” and “distal” includes “distal region.”

[0049] As detailed herein, ultrasound energy can be used to enhance the delivery and / or efficacy of therapeutic compounds. For example, in the context of treating vascular occlusion, ultrasound energy has been shown to increase enzyme-mediated thrombolysis by enhancing the delivery of thrombolytic agents into the bloodstream, where these agents lyse thrombi by degrading fibrin that forms the thrombus. The thrombolytic activity of the agent is enhanced in the presence of ultrasound energy within the thrombus. In other applications, ultrasound energy has also been shown to enhance the transfection of gene-based drugs into cells and to enhance the metastasis of chemotherapeutic drugs into tumor cells. Ultrasound energy delivered from patients has been found to produce non-thermal effects that increase the permeability of biological tissues to therapeutic compounds by up to or more than an order of magnitude.

[0050] Using ultrasound catheters to deliver ultrasound energy and therapeutic compounds directly to the treatment site can alleviate or overcome many of the drawbacks associated with systemic drug delivery, such as inefficiency, high utilization rates of therapeutic compounds, and significant side effects due to high doses. Local delivery of therapeutic compounds has been found advantageous in the context of thrombolytic therapy, chemotherapy, radiotherapy, and gene therapy, as well as in applications requiring the delivery of proteins and / or therapeutic humanized antibodies. However, it should be understood that in some arrangements, ultrasound catheters can also be used in conjunction with systemic drug delivery, either as an alternative to or as a supplement to local drug delivery. Alternatively, local drug delivery can be accomplished using a separate device, such as a catheter.

[0051] As will be described below, an ultrasonic conduit may include one or more ultrasonic radiating elements positioned therein. Such ultrasonic radiating elements may include a transducer (e.g., a PZT transducer) configured to convert electrical energy into ultrasonic energy. In such embodiments, the PZT transducer is excited by specific electrical parameters (referred herein as "power parameters" that cause it to vibrate in a manner that generates ultrasonic energy).

[0052] Referring to the illustrated embodiment, Figure 1 An ultrasound catheter 10 configured for use in a patient's vascular system is shown. For example, in some applications, the ultrasound catheter 10 is used to treat long-segment peripheral artery occlusions, such as those in the vascular system of the leg, while in other applications, the ultrasound catheter 10 is used to treat occlusions in small vessels of the neurovascular system or other parts of the body (e.g., other parts of the vascular system). Therefore, the size of the catheter 10 can be adjusted based on the specific application for which it is intended.

[0053] An ultrasound catheter or catheter system 10 typically comprises a multi-part, elongated, flexible tubular body or catheter shaft 12 having a proximal region 14 and a distal region 15. The catheter shaft 12 includes a flexible energy delivery segment 18 located in the distal region 15 of the catheter 10. The catheter shaft 12 and other components of the catheter 10 are manufactured according to various technologies. Appropriate materials and sizes are selected based on the natural and anatomical dimensions of the treatment site and the desired percutaneous entry point.

[0054] For example, in one embodiment, the proximal region 14 of the catheter shaft 12 may include a material with sufficient flexibility, kink resistance, rigidity, and structural support to propel the energy delivery segment 18 through the patient's vascular system to the treatment site. Examples of such materials include, but are not limited to, extruded polytetrafluoroethylene (PTFE), polyethylene (PE), polyamide, and other similar materials. In some embodiments, the proximal region 14 of the catheter shaft 12 may be reinforced by a braided mesh or other construction to provide increased kink resistance and maneuverability. For example, in some embodiments, nickel-titanium or stainless steel wire may be placed along or incorporated into the catheter shaft 12 to reduce kinking.

[0055] In some cases, the energy delivery segment 18 of the conduit shaft 12 may be formed of a material that is (a) thinner than the material forming the proximal region 14 of the conduit shaft 12, or (b) has greater acoustic transparency than the material forming the proximal region 14 of the conduit shaft 12. Thinner materials generally have greater acoustic transparency than thicker materials. Suitable materials for the energy delivery segment 18 include, but are not limited to, high-density or low-density polyethylene, polyurethane, nylon, etc. In some embodiments, the energy delivery segment 18 is formed of the same material or the same thickness as the proximal region 14.

[0056] One or more fluid delivery cavities may be incorporated into the catheter shaft 12. For example, in one embodiment, a central lumen extends through the catheter shaft 12. The central lumen extends the length of the catheter shaft 12 and is coupled to a distal outlet port 29 and a proximal inlet port 31. The proximal inlet port 31 forms part of a hub 33, which is attached to the proximal region 14 of the catheter 10. In some cases, the hub 33 may include a cooling fluid fitting 46 hydraulically connected to a cavity within the catheter shaft 12. In some cases, the hub 33 may also include a therapeutic compound inlet port 32 hydraulically connected to a cavity within the catheter shaft 12. In some cases, the therapeutic compound inlet port 32 may also be hydraulically coupled to a source of therapeutic compound via the hub, such as a Luer connector.

[0057] The conduit 10 is configured to have one or more ultrasonic radiating components positioned therein. For example, in some embodiments, the ultrasonic radiating components may be fixed within the tubular body energy delivery section 18, while in other embodiments, multiple ultrasonic radiating components are fixed to an assembly passing through a central cavity. In either case, one or more ultrasonic radiating components are electrically connected to the control system 100 via cable 45. In one embodiment, the outer surface of the energy delivery section 18 may include a cavitation-enhancing surface configured to enhance / promote cavitation at the treatment site. In some cases, the cavitation-enhancing surface is a textured surface that can retain small air pockets upon immersion. Small cavitation pockets can serve as a source of microbubbles or nanobubbles, thereby lowering the cavitation threshold in the ultrasonic field. In some cases, the outer surface of the energy delivery section 18 may be coated with a coating comprising components that will lower the cavitation threshold. As an example, the surface may be hydrophobic and textured in such a way that the textured surface exhibits a lower cavitation threshold than the surrounding bulk fluid. This can enhance the therapeutic effect of the ultrasound.

[0058] refer to Figures 2 to 8 An exemplary arrangement of the energy delivery section 18 and other portions of the catheter 10 described above is shown. This arrangement may be well-suited for treating peripheral vascular occlusion.

[0059] Figure 2 It shows along Figure 1 The cross-section of the conduit shaft 12 is taken from line 2-2. For example... Figure 2 As shown, three fluid delivery chambers 30 can be incorporated into the catheter shaft 12. In other embodiments, more or fewer fluid delivery chambers can be incorporated into the catheter shaft 12. The catheter shaft 12 may include a hollow central cavity 51 passing through the catheter shaft 12. Figure 2As shown, the cross-section of the conduit shaft 12 can be substantially constant along most of the length of the conduit 10. Therefore, in such an embodiment, substantially the same cross-section exists in both the proximal region 14 and the distal region 15 of the conduit 10. In some cases, the cross-section can vary within the energy delivery section 18, as will be discussed later.

[0060] In some embodiments, the minimum diameter of the central cavity 51 is greater than about 0.030 inches (about 0.0762 cm). In another embodiment, the minimum diameter of the central cavity 51 is greater than about 0.037 inches (about 0.09398 cm). In one example embodiment, the fluid delivery cavity 30 has dimensions of about 0.026 inches (about 0.06604 cm) wide × about 0.0075 inches (about 0.01905 cm) high; however, other dimensions may be used in other applications.

[0061] As described above, the central lumen 51 can extend through the length of the catheter shaft 12. Figure 1 As shown, the central cavity 51 includes a distal outlet port 29 and a proximal inlet port 31. The proximal inlet port 31 forms part of a hub 33, which is attached to the proximal region 14 of the catheter 10. The central cavity 51 can be configured to receive an elongated inner core 34, in Figure 3 An embodiment of an elongated inner core 34 is shown. In some cases, the elongated inner core 34 includes a proximal region 36 and a distal region 38. A proximal hub 37 is fitted onto the inner core 34 at one end of the proximal region 36. One or more ultrasonic radiating members are positioned within an inner core energy delivery section 41 located within the distal region 38. The ultrasonic radiating members 40 form an ultrasonic assembly 42, which will be described in detail below.

[0062] As along Figure 3 The line 4-4 was cut Figure 4 As shown in the cross-section, the inner core 34 may be cylindrical, with an outer diameter that allows it to be inserted into the central lumen 51 of the catheter shaft 12 via the proximal inlet port 31. Suitable outer diameters of the inner core 34 include, but are not limited to, from about 0.010 inches (about 0.0254 cm) to about 0.100 inches (about 0.254 cm). In another embodiment, the outer diameter of the inner core 34 is between about 0.020 inches (about 0.0508 cm) and about 0.080 inches (about 0.2032 cm). In yet another embodiment, the outer diameter of the inner core 34 is about 0.035 inches (about 0.0889 cm).

[0063] Still referencing Figure 4 The inner core 34 may include a cylindrical outer body 35 that houses the ultrasonic component 42. The ultrasonic component 42 includes... Figures 5 to 7DThe wiring and ultrasonic radiating components are described in more detail below, enabling the ultrasonic assembly 42 to radiate ultrasonic energy from the energy delivery section 41 of the inner core 34. The ultrasonic assembly 42 is electrically connected to the hub 33, where the inner core 34 can be connected via cable 45 to the control system 100 (e.g., [missing information]). Figure 1 (As shown). In some cases, an electrically insulating potting material 43 fills the inner core 34 surrounding the ultrasonic component 42, thereby preventing movement of the ultrasonic component 42 relative to the outer body 35. In one embodiment, the thickness of the outer body 35 is between about 0.0002 inches (about 0.000508 cm) and 0.010 inches (0.0254 cm). In another embodiment, the thickness of the outer body 35 is between about 0.0002 inches (about 0.000508 cm) and 0.005 inches (0.0127 cm). In yet another embodiment, the thickness of the outer body 35 is about 0.0005 inches (about 0.00127 cm).

[0064] In some embodiments, the ultrasonic component 42 includes a plurality of ultrasonic radiating members 40, which are divided into one or more groups. For example, Figures 5 to 6 This is a schematic wiring diagram illustrating a technique for connecting five groups of ultrasonic radiating elements 40 to form an ultrasonic assembly 42. The ultrasonic assembly 42 includes a set of transducer drivers 109, each comprising a transducer driver that drives each of the five groups of ultrasonic radiating elements 40 (G1, G2, G3, G4, G5) via electrical connections 110a, 110b, 110c, 110d, and 110e. The five groups of ultrasonic radiating elements 40 (G1, G2, G3, G4, G5) are also electrically connected to a control system 100. In some cases, a single amplifier is used, for example, which has a MUX for driving each of the groups.

[0065] As used herein, the terms “ultrasonic energy,” “ultrasonic,” and “ultrasonic” are broad terms with their common meanings and further refer to, but are not limited to, mechanical energy transferred by longitudinal pressure or compression waves. Ultrasonic energy can be emitted as continuous waves or pulsed waves, depending on the requirements of a particular application. Additionally, ultrasonic energy can be emitted as waveforms of various shapes, such as sine waves, triangle waves, square waves, or other waveforms. Ultrasonic energy includes sound waves. In some embodiments, the frequency of the ultrasonic energy is between about 20 kHz and about 20 MHz. For example, in one embodiment, the frequency of the wave is between about 500 kHz and about 20 MHz. In another embodiment, the frequency of the wave is between about 1 MHz and about 3 MHz. In yet another embodiment, the frequency of the wave is about 2 MHz. The average acoustic power of each ultrasonic radiating element 40 is between about 0.01 watts and 300 watts. In some embodiments, the average acoustic power of each ultrasonic radiating element 40 is between about 0.2 watts and about 2.5 watts. In one embodiment, the average acoustic power of each ultrasonic radiating element 40 is about 0.27 watts.

[0066] As used herein, the term "ultrasonic radiating element" refers to any device capable of generating ultrasonic energy. For example, in one embodiment, an ultrasonic radiating element includes an ultrasonic transducer that converts electrical energy into ultrasonic energy. Suitable examples of ultrasonic transducers for generating ultrasonic energy from electrical energy include, but are not limited to, piezoelectric ceramic oscillators. Piezoelectric ceramics can comprise crystalline materials, such as quartz, which change shape when an electric current is applied to the material. This change in shape, caused by an oscillating driving signal, creates ultrasonic waves. In other embodiments, ultrasonic energy may be generated by an ultrasonic transducer located away from the ultrasonic radiating element, and the ultrasonic energy may be transmitted via, for example, a wire coupled to the ultrasonic radiating element.

[0067] Still referencing Figure 5 The control circuit 100 may include a voltage source 102, etc. The voltage source 102 includes a positive terminal 104 and a negative terminal 106. The negative terminal 106 is connected to a common line 108 that connects five sets of G1-G5 ultrasonic radiating components 40 in series. The positive terminal 104 is connected to multiple wires 110a, 110b, 110c, 110d, and 110e, which are respectively connected to one of the five sets of G1-G5 ultrasonic radiating components 40. Therefore, in this configuration, each of the five sets of G1-G5 ( Figure 6 One set of wires (shown in the diagram) is connected to the positive terminal 104 via one of wires 110a, 110b, 110c, 110d, and 110e, and to the negative terminal 106 via a common line 108. The control circuitry can be configured as part of the control system 100 and can include circuitry, control routines, controllers, etc., configured to change one or more power parameters used to drive the ultrasonic radiation member 40.

[0068] Now for reference Figure 6 Each group G1-G5 includes multiple ultrasonic radiating elements 40. Each of the ultrasonic radiating elements 40 is electrically connected to a common line 108 and a conductor 110 via one of two positive contact wires 112. Therefore, when wired as shown, a constant voltage difference is applied to each ultrasonic radiating element 40 in the group. Although Figure 6 The illustrated group includes 12 ultrasonic radiating elements 40, but those skilled in the art will recognize that the group may include more or fewer ultrasonic radiating elements 40. Similarly, in Figure 5 The ultrasound assembly 42 shown may include more or fewer than five groups.

[0069] Figure 7A An ultrasound component 42 (such as...) is shown. Figure 5 The components (illustrated in the diagram) are arranged into the inner core 34 (e.g. Figure 4An example technique is shown schematically in the diagram. Figure 7A yes Figure 5 A cross-sectional view of the ultrasound component 42 taken within group G1, as indicated by the presence of the four guide wires 110. For example, if in Figure 5 If a cross-sectional view of the ultrasound component 42 is taken from group G4, then only one wire 110 will exist (i.e., the wire connecting group G5).

[0070] Still referencing Figure 7A The common line 108 comprises an elongated, flat piece of conductive material that makes electrical contact with a pair of ultrasonic radiating elements 40. Each of the ultrasonic radiating elements 40 also makes electrical contact with a positive contact line 112. Because the common line 108 is connected to the negative terminal 106 and the positive contact line 112 is connected to the positive terminal 104, a voltage difference can be created across each ultrasonic radiating element 40. The conductor 110 can be separated from other components of the ultrasonic assembly 42 to prevent interference with the operation of the ultrasonic radiating elements 40 as described above. For example, in one embodiment, the inner core 34 can be filled with an insulating potting material 43 to prevent unwanted electrical contacts between the various components of the ultrasonic assembly 42.

[0071] Figure 7B and Figure 7C The cuts along lines 7B-7B and 7C-7C are shown respectively. Figure 7A A cross-sectional view of the inner core 34. (See image.) Figure 7B As shown, ultrasonic radiating components 40 are mounted in pairs along a common line 108. The ultrasonic radiating components 40 are connected by a positive contact line 112, such that substantially the same voltage is applied to each ultrasonic radiating component 40. Figure 7C As shown, the common line 108 may include a wide region 108W on which the ultrasonic radiating components 40 may be mounted, thereby reducing the likelihood that pairs of ultrasonic radiating components 40 will short-circuit together. In some embodiments, outside the wide region 108W, the common line 108 may have a more conventional, circular shape.

[0072] In one embodiment, such as, Figure 7D As shown, the common line 108 can be twisted to form a spiral shape before being fixed within the inner core 34. In such an embodiment, the ultrasonic radiating member 40 is oriented in multiple radial directions, thereby enhancing the radial uniformity of the generated ultrasonic field.

[0073] Those skilled in the art will recognize that the above wiring arrangement can be modified to allow each group of G1, G2, G3, G4, G5 to be powered independently. Specifically, by providing a separate power supply to each group within the control system 100, each group can be individually turned on or off, or driven with a personalized power. This provides the ability to “turn off” the delivery of ultrasound energy in the area of ​​the treatment site where treatment has been completed, thereby preventing the application of harmful or unnecessary ultrasound energy to the patient.

[0074] The above and Figure 5 The embodiment shown in Figure 7 illustrates multiple ultrasonic radiating elements grouped in space. That is, in such an embodiment, all ultrasonic radiating elements within a group are positioned adjacent to each other, such that when a single group is activated, ultrasonic energy is delivered along a specific length of the ultrasonic assembly. However, in some embodiments, the ultrasonic radiating elements within a group may be spaced apart from each other, such that the ultrasonic radiating elements within a group are not positioned adjacent to each other. In such an embodiment, when a single group is activated, ultrasonic energy can be delivered from a larger, spaced-apart portion of the energy delivery section. This modified embodiment may be advantageous in applications where it is desired to deliver a less focused, more diffuse ultrasonic energy field to a treatment site.

[0075] In some embodiments, the ultrasonic radiating member 40 may include a rectangular lead zirconate titanate ("PZT") ultrasonic transducer with dimensions of approximately 0.017 inches (approximately 0.04318 cm) × approximately 0.010 inches (approximately 0.0254 cm) × approximately 0.080 inches (0.2032 cm). In other embodiments, other configurations may be used. For example, a disc-shaped ultrasonic radiating member 40 may be used in other embodiments. In one embodiment, the common wire 108 comprises copper and is approximately 0.005 inches (approximately 0.0127 cm) thick; however, other conductive materials and other dimensions may be used in other embodiments. For example, the conductor 110 may be a 36 gauge conductor, while the positive contact wire 112 may be a 42 gauge conductor. However, those skilled in the art will recognize that other wire gauges may be used in other embodiments.

[0076] As described above, suitable frequencies for the ultrasonic radiating element 40 include, but are not limited to, about 20 kHz to about 20 MHz. In one embodiment, the frequency is between about 500 kHz and 20 MHz, and in another embodiment, between 1 MHz and 3 MHz. In yet another embodiment, the ultrasonic radiating element 40 operates at a frequency of about 2 MHz.

[0077] Figure 8 The inner core 34, positioned within the catheter shaft 12, is shown. For clarity, details are omitted. Figure 7ADetails regarding the ultrasound component 42 are provided below. As described above, the inner core 34 can slide within the central cavity 51 of the catheter shaft 12, thereby allowing the inner core energy delivery section 41 to be positioned within the tubular body energy delivery section 18. For example, in one embodiment, the materials comprising the inner core energy delivery section 41, the tubular body energy delivery section 18, and the potting material 43 can all be materials with similar acoustic impedance, thereby minimizing ultrasound energy loss across material interfaces.

[0078] Figure 8 The placement of the fluid delivery port 58 within the tubular body energy delivery section 18 is further illustrated. As shown, an orifice or slit is formed by a fluid delivery chamber 30 via the conduit shaft 12, thereby allowing fluid flow from the fluid delivery chamber 30 to the treatment site. Therefore, a source of therapeutic compound coupled to the inlet port 32 provides hydraulic pressure, which drives the therapeutic compound through the fluid delivery chamber 30 and out of the fluid delivery port 58.

[0079] like Figure 8 As shown, by uniformly spacing the fluid delivery cavities 30 around the circumference of the catheter shaft 12, substantially uniform flow of the therapeutic compound around the circumference of the catheter shaft 12 can be achieved. Additionally, the size, location, and geometry of the fluid delivery ports 58 can be selected to provide uniform fluid flow from the fluid delivery ports 30 to the treatment site. For example, in one embodiment, the fluid delivery ports closer to the proximal region of the energy delivery segment 18 have a smaller diameter than the fluid delivery ports closer to the distal region of the energy delivery segment 18, thereby allowing uniform fluid delivery across the entire energy delivery segment.

[0080] For example, in one embodiment where the fluid delivery port 58 has a similar size along the length of the conduit shaft 12, the fluid delivery port 58 has a diameter between about 0.0005 inches (about 0.00127 cm) and about 0.0050 inches (about 0.0127 cm). In another embodiment where the size of the fluid delivery port 58 varies along the length of the conduit shaft 12, the fluid delivery port 58 has a diameter between about 0.001 inches (about 0.00254 cm) and about 0.005 inches (about 0.0127 cm) in the proximal region of the energy delivery section 18 (see example). Figure 1The fluid delivery port 58 has a diameter between approximately 0.005 inches (approximately 0.0127 cm) and 0.020 inches (0.0508 cm) in the distal region of the energy delivery section 18. The dimensional increase between adjacent fluid delivery ports 58 depends on the material comprising the conduit shaft 12 and the size of the fluid delivery cavity 30. The fluid delivery ports 58 can be created in the conduit shaft 12 by punching, drilling, burning or ablation (e.g., with a laser), or by any other suitable method. The flow of therapeutic compounds along the length of the conduit shaft 12 can also be increased by increasing the density of the fluid delivery ports 58 toward the distal region 15 of the conduit shaft 12.

[0081] In the case of delivering cavitation nuclei, such as microbubbles, nanobubbles, microdroplets, or nanodroplets, it may be advantageous to make the fluid delivery port 58 large enough that the cavitation nuclei are not subjected to excessive pressure or shear stress as they pass through the fluid delivery cavity 30 and exit the fluid delivery port 58. It should be understood that a non-uniform fluid flow from the fluid delivery port 58 to the treatment site may be required. In such embodiments, the size, location, and geometry of the fluid delivery port 58 can be selected to provide this non-uniform fluid flow.

[0082] Still referencing Figure 8 The placement of the inner core 34 within the conduit shaft 12 also defines a cooling fluid cavity 44. The cooling fluid cavity 44 is formed between the outer surface 39 of the inner core 34 and the inner surface 16 of the conduit shaft 12. In some embodiments, cooling fluid can be introduced through the proximal inlet port 31, such that cooling fluid flow is generated through the cooling fluid cavity 44 and flows out from the distal outlet port 29 (see...). Figure 1 In some cases, the cooling fluid cavities 44 may be uniformly spaced around the circumference of the catheter axis 12 (i.e., in increments of approximately 120° for a three-cavity configuration), thereby providing uniform cooling fluid flow over the inner core 34. This configuration is useful for removing unwanted heat energy at the treatment site. The flow rate of the cooling fluid and the power of the ultrasound assembly 42 can be adjusted to maintain the temperature of the distal region 15 of the catheter 10 within a desired range. In some cases, the desired temperature range may be between 28°C and 52°C. In some cases, the desired temperature range may be between 28°C and 45°C. In some cases, the desired temperature range may be between 28°C and 43°C.

[0083] In one embodiment, the inner core 34 can rotate or move within the conduit shaft 12. Specifically, movement of the inner core 34 can be achieved by manipulating the proximal hub 37 while keeping the hub 33 stationary. The inner core outer body 35 is at least partially constructed of a material that provides sufficient structural support to allow the inner core 34 to move within the conduit shaft 12 without kinking the conduit shaft 12. Additionally, the inner core outer body 35 may include a material capable of transmitting torque. Suitable materials for the inner core outer body 35 include, but are not limited to, polyimide, polyester, polyurethane, thermoplastic elastomers, and braided polyimide.

[0084] In one embodiment, the fluid delivery chamber 30 and the cooling fluid chamber 44 are open at the distal end of the catheter shaft 12, allowing the therapeutic compound and cooling fluid to enter the patient's vascular system at the distal outlet port. Alternatively, if necessary, the fluid delivery chamber 30 can be selectively occluded at the distal end of the catheter shaft 12, providing additional hydraulic pressure to drive the therapeutic compound out of the fluid delivery port 58. In either configuration, the inner core 34 can be prevented from passing through the distal outlet port by making its length less than the length of the tubular body. In other embodiments, a protrusion is formed on the inside of the tubular body in the distal region 15 to prevent the inner core 34 from passing through the distal outlet port.

[0085] In other embodiments, catheter 10 may also include an occlusion device (not shown) positioned at the distal outlet port 29. The occlusion device may have a reduced inner diameter that can accommodate the guidewire but is smaller than the inner diameter of the central lumen 51. This prevents the inner core 34 from extending through the occlusion device and exiting the distal outlet port 29. Suitable inner diameters for the occlusion device include, but are not limited to, approximately 0.005 inches (approximately 0.0127 cm) to approximately 0.050 inches (approximately 0.127 cm). In other embodiments, the occlusion device has a closed end, thereby preventing cooling fluid from leaving catheter 10 and instead recirculating it to the proximal region 14 of catheter shaft 12. These and other cooling fluid flow configurations allow the power supplied to the ultrasound assembly 42 to be increased proportionally to the flow rate of the cooling fluid. Additionally, certain cooling fluid flow configurations can reduce the patient's exposure to the cooling fluid.

[0086] In some embodiments, such as Figure 8 As shown, the conduit shaft 12 may also include one or more temperature sensors 20, which may be located within the energy delivery section 18. In such an embodiment, the proximal region 14 of the conduit shaft 12 includes temperature sensor leads, which may be incorporated into the cable 45 (e.g., Figure 1(As shown). Suitable temperature sensors include, but are not limited to, temperature sensing diodes, thermistors, thermocouples, resistance temperature detectors ("RTDs"), and fiber optic temperature sensors using thermochromic liquid crystals. The geometry of a suitable temperature sensor 20 includes, but is not limited to, dots, patches, or stripes. The temperature sensor 20 may be located within one or more fluid delivery chambers 30 (as shown), and / or within one or more cooling fluid chambers 44.

[0087] The ultrasonic radiating element can operate in a pulsed mode. For example, in one embodiment, the time-averaged electrical power supplied to the ultrasonic radiating element 40 is between about 0.001 watts and 5 watts, and can be between about 0.05 watts and about 3 watts. In some embodiments, the time-averaged electrical power over the processing time is about 0.45 watts or 1.2 watts. The duty cycle is between about 0.01% and about 90%, and can be between 0.1% and about 50%. In some embodiments, the duty cycle varies between about 7.5%, 15%, or 1% and 30%. The pulse-averaged electrical power of each ultrasonic radiating element 40 can be between about 0.01 watts and about 20 watts, and can be between about 0.1 watts and 20 watts. In some embodiments, the pulse-averaged electrical power varies between about 4 watts, 8 watts, 16 watts, or 0.5 to 8 watts. As described above, the amplitude, pulse width, pulse repetition frequency, peak negative sound pressure level, or any combination of these parameters can be constant or variable during each pulse or a set of pulses. In nonlinear applications of acoustic parameters, the above ranges can vary significantly. Therefore, the total time-averaged electrical power over the treatment period may remain constant, but it is not the real-time average power.

[0088] In one embodiment, the pulse repetition rate can be between about 1 Hz and about 2 kHz, and more commonly between about 1 Hz and about 50 Hz. In another embodiment, the pulse repetition rate varies from about 30 Hz or about 10 Hz to about 40 Hz. The pulse duration or width can be between about 0.5 ms and about 50 ms, and more commonly between about 0.1 ms and about 25 ms. In some embodiments, the pulse duration varies from about 2.5 ms, 5, or 1 to 8 ms. Additionally, the peak negative sound pressure level can be between about 0.1 and about 50 MPa, or in another embodiment between about 0.5 and about 2.0 MPa.

[0089] In one embodiment, the transducer operates with an average power of about 0.6 watts, a duty cycle of about 7.5%, a pulse repetition rate of about 30 Hz, an average pulse power of about 8 watts, and a pulse duration of about 2.5 milliseconds.

[0090] The acoustic efficiency of the ultrasonic radiating element used with the electrical parameters described herein may be greater than about 50% and may be greater than about 75%. The ultrasonic radiating element can be formed in various shapes, such as cylindrical (solid or hollow), flat, strip-shaped, triangular, etc. The length of the ultrasonic radiating element can be between about 0.1 cm and about 0.7 cm. The thickness of the ultrasonic radiating element can be between about 0.02 cm and about 0.5 cm.

[0091] In some embodiments, the therapeutic crop delivered to the treatment site comprises multiple bubbles, such as microbubbles, having, for example, a gas formed therein. Example gases that can be used to form microbubbles include, but are not limited to, air, oxygen, carbon dioxide, perfluorocarbon gas, and inert gases.

[0092] In some embodiments, the microbubble therapeutic compound may include approximately 10 μL per milliliter of liquid. 4 Approximately 10 microbubbles per millimeter of liquid. 10 Microbubbles, or about 10 per milliliter of liquid 6 To about 10 9 Microbubbles. In some embodiments, the diameter of the microbubbles in the microbubble therapeutic compound is between about 0.1 μm and about 30 μm. In some embodiments, the diameter of the microbubbles is about 0.1 to about 10 μm, about 0.2 to about 10 μm, about 0.5 to about 10 μm, about 0.5 to about 5 μm, or about 1 μm. In some embodiments, the diameter of the microbubbles is less than or equal to about 10 μm, about 5 μm, or about 2.5 μm. In other embodiments, other parameters may be used.

[0093] In some embodiments, the efficacy of the therapeutic compound is enhanced by the presence of microbubbles contained therein. In some embodiments, the microbubbles can act as nuclei for cavitation, and thus allow cavitation to be induced at lower levels of peak rarefaction sound pressure. Therefore, a reduced amount of peak rarefaction sound pressure can be delivered to the treatment site without diminishing the therapeutic efficacy. Reducing the amount of ultrasonic pressure delivered to the treatment site lowers the risk associated with overheating the treatment site, and in some embodiments, also reduces the time required to treat the blood vessel. In some embodiments, cavitation also facilitates more efficient diffusion and penetration of the therapeutic compound into surrounding tissues, such as the vessel wall and / or clot material. Furthermore, in some embodiments, the mechanical agitation caused by the cavitation of microbubbles is effective in the mechanical breakdown of clot material.

[0094] It should be understood that interactions between a fluid (e.g., a therapeutic material) and / or microbubbles delivered via a fluid delivery cavity, achieved using ultrasonic energy emitted by an ultrasonic transmitter, can lead to microbubble rupture and / or other bursting. Microbubble bursting at or near the target site can help improve the effectiveness / efficacy of the therapeutic material. It should also be understood that if microbubbles burst before the therapeutic material reaches the target site, the benefits of the microbubbles may be reduced or lost. In other words, premature bursting of microbubbles may reduce the effectiveness of the fluid / therapeutic material and / or the overall treatment. This document discloses a system comprising structures configured to shield and / or protect microbubbles delivered via a fluid delivery cavity from the ultrasonic energy emitted by an ultrasonic transmitter. This can help reduce or prevent microbubble bursting before reaching the target site and / or otherwise maximize the therapeutic benefits of the microbubbles.

[0095] Figure 9 A portion of an example system 210 disposed within a blood vessel 259 is depicted. This system 210 may be similar in form and function to other systems disclosed herein. System 210 may include a catheter shaft 212 and a treatment core 234 disposed therein (e.g., within a central lumen 251 of the catheter shaft 212). The treatment core 234 may include a plurality of ultrasound transducers 240. The ultrasound transducers 240 may be configured to emit ultrasound energy and are generally indicated by reference numeral 260. System 210 may be advanced through the blood vessel to a location adjacent to a target region. This may include advancing system 210 through a guide catheter or inserter 253.

[0096] In this example, the fluid delivery cavity is formed in and / or otherwise defined by one or more tubular members 262. In at least some cases, the one or more tubular members 262 may be formed as separate structures positioned near the catheter axis 212. Typically, the tubular members 262 are configured to deliver fluid (e.g., therapeutic substances and / or microbubbles) to a target area. Figure 9 In this drawing, microbubbles are schematically depicted and identified by reference numeral 266. The structure of the tubular member 262 can also provide a degree of shielding and / or protection. For example, the walls of the tubular member 262 can help block or reduce the amount of ultrasound energy 260 that may engage with the microbubbles 266. This is desirable for a variety of reasons. For example, by shielding / protecting the microbubbles 266 from the ultrasound energy 260 (e.g., before reaching the target site), the microbubbles 266 are less likely to burst or otherwise rupture before reaching the target area. Because the microbubbles 266 remain largely intact, they are more likely to have the desired effect on the therapeutic efficacy of the target area.

[0097] The tubular member 262 may have an opening 264 therein. The opening 264 is configured to allow fluid (e.g., therapeutic fluid, material, and / or substance) and / or microbubbles 266 to flow out of the tubular member 262. For example, microbubbles 266 may flow toward a target within the tubular member 262. In this process, the structure and / or configuration of the tubular member 262 may shield / protect the microbubbles 266. Upon reaching the target area, the microbubbles 266 may exit the tubular member 262. This allows the desired amount of fluid (e.g., therapeutic fluid, material, and / or substance) and / or microbubbles 266 (e.g., intact microbubbles 266) to be present at the target area. The fluid and microbubbles 266 may interact with ultrasound energy 260 at the target area to treat blood vessels.

[0098] Figures 10 to 11 A portion of an example system 310 disposed within a blood vessel 359 is depicted. This system 310 may be similar in form and function to other systems disclosed herein. System 310 may include a catheter shaft 312 and a treatment core 334 disposed therein (e.g., within a central lumen 351 of the catheter shaft 312). The treatment core 334 may include a plurality of ultrasound transducers 340. The ultrasound transducers 340 may be configured to emit ultrasound energy and are generally indicated by reference numeral 360. System 310 may be advanced through the blood vessel to a location adjacent to a target region. This may include advancing system 310 through a guide catheter or inserter 353.

[0099] In this example, the fluid delivery cavity 362 is formed and / or otherwise defined in, such as Figure 11 The catheter shaft 312 is shown. For example, a fluid delivery cavity 362 may be formed in the wall of the catheter shaft 312. Typically, the fluid delivery cavity 362 is configured to deliver fluid (e.g., therapeutic substances and / or microbubbles) to a target area. The fluid delivery cavity 362 may also include providing a degree of shielding and / or protection. For example, the fluid delivery cavity 362 may include a fluid delivery area or tube 368. The fluid delivery tube 368 may be shielded / protected. For example, a cavitation 370 may be disposed within the fluid delivery cavity 362 and positioned near the fluid delivery tube 368. Since air may not be an ideal medium for delivering ultrasound energy, the cavitation 370 may help block or reduce the amount of ultrasound energy 360 that may engage with the microbubbles 366. This may help shield / protect the microbubbles 366 from the ultrasound energy 360 (e.g., before reaching the target site). Therefore, the microbubbles 366 are less likely to burst or otherwise rupture before reaching the target area, which may have the desired effect on the therapeutic efficacy of the target area.

[0100] The fluid delivery chamber 362 and / or fluid delivery tube 368 may have an opening 364 therein. The opening 364 is configured to allow fluid (e.g., therapeutic fluid, material, and / or substance) and / or microbubbles 366 to flow out from the fluid delivery tube 368 (and / or fluid delivery chamber 362). For example, microbubbles 366 may flow toward a target within the fluid delivery tube 368 (and / or fluid delivery chamber 362). During this process, cavitation 370 may shield / protect the microbubbles 366. Upon reaching the target area, the microbubbles 366 may exit the fluid delivery tube 368 (and / or fluid delivery chamber 362). This allows the desired amount of fluid (e.g., therapeutic fluid, material, and / or substance) and / or microbubbles 366 (e.g., intact microbubbles 366) to be present at the target area. The fluid and microbubbles 366 may interact with ultrasound energy 360 at the target area to treat blood vessels.

[0101] Figure 12 A portion of an example system 410 is depicted, which may be similar in form and function to other systems disclosed herein. In this example, a fluid delivery cavity 462 is formed and / or otherwise defined within a catheter shaft 412. For example, the fluid delivery cavity 462 may be formed within the wall of the catheter shaft 412. Typically, the fluid delivery cavity 462 is configured to deliver fluid (e.g., therapeutic material and / or microbubbles) to a target area. The fluid delivery cavity 462 is arranged to provide a degree of shielding and / or protection. For example, the fluid delivery cavity 462 may be arranged within the catheter shaft 412 to deflect the ultrasonic energy 460a, 460b delivered by an ultrasonic transducer 440 (e.g., which may be part of a treatment core 434 similar to other treatment cores), which may help block or reduce the amount of ultrasonic energy 460a, 460b that may engage with microbubbles. For example, the ultrasonic transducer 440 may emit ultrasonic energy 460a, 460b in one or more generally directional directions. For example, ultrasound energy 460a can be projected in a first direction, and ultrasound energy 460b can be projected in a second direction. This can create regions (e.g., quieter regions or dead zones) where the relative amount of ultrasound energy is reduced. A fluid delivery cavity 462 can be arranged along the catheter axis 412 such that the fluid delivery cavity 462 is positioned in such a quieter / dead zone, offset from the ultrasound energies 460a and 460b. Therefore, microbubbles are less likely to burst or otherwise rupture before reaching the target area, which may have the desired effect on the therapeutic efficacy of the target area.

[0102] The fluid delivery cavity 462 may have an opening 464 therein. The opening 464 is configured to allow fluid (e.g., therapeutic fluid, material, and / or substance) and / or microbubbles to flow out therefrom. For example, microbubbles may flow toward a target within the fluid delivery cavity 462. The arrangement of the fluid delivery cavity 462, for example, relative to the ultrasonic energy 460a, 460b emitted from the ultrasonic transducer 440, may shield / protect the microbubbles. Upon reaching the target area, the microbubbles may exit the fluid delivery cavity 462. This allows the desired amount of fluid (e.g., therapeutic fluid, material, and / or substance) and / or microbubbles (e.g., intact microbubbles) to be present at the target area. The fluid and microbubbles may interact with the ultrasonic energy 460a, 460b at the target area to treat the blood vessel.

[0103] Materials that can be used for various components of the devices described herein may include those commonly associated with medical devices. The devices and their components described herein may be made of metals, metal alloys, polymers (some examples of which are disclosed below), metal-polymer composites, ceramics, combinations thereof, or other suitable materials. Some examples of suitable polymers may include polytetrafluoroethylene (PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene propylene (FEP), polyoxyethylene (POM, e.g., DELRIN®, available from DuPont), polyether block copolymers, polyurethanes (e.g., polyurethane 85A), polypropylene (PP), polyvinyl chloride (PVC), polyether copolymers (e.g., ARNITEL®, available from DSM Engineering Plastics), ether- or ester-based copolymers (e.g., phthalate / poly(hydrocarbon ether) and / or other polyester elastomers, such as HYTREL®, available from DuPont), polyamides (e.g., DURETHAN®, available from Bayer, or CRISTAMID®, available from Elf Atochem), elastomeric polyamides, block polyamides / ethers, polyether block amides (PEBA, e.g., available under the trade name PEBAX®), ethylene-vinyl acetate copolymers (EVA), silicone resins, polyethylene (PE), high-density polyethylene, low-density polyethylene, etc. Linear low-density polyethylene (e.g., REXELL®), polyester, polybutylene terephthalate (PBT), polyethylene terephthalate (PET), polypropylene terephthalate, polyethylene naphthalate (PEN), polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI), polyphenylene sulfide (PPS), polyphenylene ether (PPO), poly(p-phenylene terephthalamide) (e.g., KEVLAR®), polysulfone, nylon, nylon-12 (such as GRILAMID®, commercially available from EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene-vinyl alcohol, polyolefins, polystyrene, epoxy resins, polyvinylidene chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (e.g., SIBS and / or SIBS) 50A), polycarbonate, ionomer, biocompatible polymer, other suitable materials or mixtures, combinations, copolymers, polymer / metal composites, etc. In some embodiments, the sheath may be mixed with a liquid crystal polymer (LCP). For example, the mixture may contain up to about 6 percent LCP.

[0104] Some examples of suitable metals and metal alloys include stainless steels such as 304V, 304L, and 316LV stainless steels; low-carbon steels; nickel-titanium alloys such as linear elastic and / or hyperelastic nickel-titanium; other nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS: N06625, such as INCONEL® 625; UNS: N06022, such as HASTELLOY® C-22®; UNS: N10276, such as HASTELLOY® C276®, other HASTELLOY® alloys, etc.), nickel-copper alloys (e.g., UNS: N04400, such as MONEL® 400, NICKELVAC® 400, NICORROS® 400, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, such as MP35-N®, etc.), and nickel-molybdenum alloys (e.g., UNS: N10665, such as HASTELLOY® ALLOY). B2®), other nickel-chromium alloys, other nickel-molybdenum alloys, other nickel-cobalt alloys, other nickel-iron alloys, other nickel-copper alloys, other nickel-tungsten or tungsten alloys, etc.; cobalt-chromium alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as ELGILOY®, PHYNOX®, etc.); platinum-rich stainless steel; titanium; combinations thereof; etc.; or any other suitable material.

[0105] In at least some embodiments, part or all of the device described herein may also be doped with, made of, or otherwise comprised of a radiopaque material. A radiopaque material should be understood as one capable of producing a relatively bright image on a fluorescent screen or using another imaging technique during medical procedures. This relatively bright image helps the user of the device described herein to determine its location. Some examples of radiopaque materials may include, but are not limited to, gold, platinum, palladium, tantalum, tungsten alloys, polymeric materials loaded with radiopaque fillers, etc. Additionally, other radiopaque marking strips and / or coils may also be incorporated into the design of the device described herein to achieve the same result.

[0106] In some embodiments, a degree of magnetic resonance imaging (MRI) compatibility is imparted to the device described herein. For example, the device or portions thereof described herein may be made of materials that substantially do not distort images and create a large number of artifacts (e.g., gaps in the image). For example, certain ferromagnetic materials may not be suitable because they may produce artifacts in MRI images. The device or portions thereof described herein may also be made of materials that an MRI machine can image. Some materials exhibiting these properties include, for example, tungsten, cobalt-chromium-molybdenum alloys (e.g., UNS: R30003, such as ELGILOY®, PHYNOX®, etc.), nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R30035, such as MP35-N®, etc.), nickel-titanium, etc.

[0107] It should be understood that the present invention is illustrative in many respects only. Changes may be made in details, particularly in terms of shape, size, and arrangement of steps, without departing from the scope of the invention. To the appropriate extent, this may include the use of any of the features of an exemplary embodiment used in other embodiments. Of course, the scope of the invention is defined by the language of the appended claims.

Claims

1. A system for treating a vascular region, the system comprising: A slender duct shaft with a distal region; The central cavity is formed within the slender conduit shaft; The treatment core disposed within the central cavity includes a plurality of ultrasonic transducers disposed near the distal region of the elongated catheter shaft. The catheter shaft includes a fluid delivery chamber disposed near the central cavity, the fluid delivery chamber being configured to deliver microbubbles and / or fluid therein; and Wherein, at least a portion of the fluid delivery cavity is arranged relative to the central cavity, such that the microbubbles and / or fluid disposed within the fluid delivery cavity are protected from the ultrasonic energy emitted from the plurality of ultrasonic transducers.

2. The system of claim 1, wherein the fluid delivery cavity is formed in the conduit shaft.

3. The system according to any one of claims 1 to 2, wherein each of the plurality of ultrasonic transducers is configured to emit ultrasonic energy in a first direction, and wherein, The fluid delivery cavity is offset from the first direction.

4. The system according to any one of claims 1 to 3, wherein each of the plurality of ultrasonic transducers is configured to emit ultrasonic energy in a first direction and a second direction, and wherein, The fluid delivery cavity is deviated from the first direction and deviated from the second direction.

5. The system according to any one of claims 1 to 4, wherein the fluid delivery cavity is formed in the wall of the conduit shaft.

6. The system according to any one of claims 1 to 5, wherein the fluid delivery chamber includes one or more side holes formed therein, the side holes extending through the wall of the conduit shaft.

7. The system according to any one of claims 1 to 6, wherein the fluid delivery chamber is defined by a tubular member disposed near the conduit shaft.

8. The system of claim 7, wherein the tubular member is configured to protect the microbubbles and / or fluid disposed within the fluid delivery chamber from ultrasonic energy emitted from the plurality of ultrasonic transducers.

9. The system according to any one of claims 1 to 8, wherein the fluid delivery chamber comprises a cavitation cavity.

10. The system of claim 9, wherein the cavitation is configured to protect the microbubbles and / or fluid disposed within the fluid delivery chamber from ultrasonic energy emitted from the plurality of ultrasonic transducers.

11. The system according to any one of claims 1 to 10, further comprising one or more additional fluid delivery chambers disposed near the central cavity.

12. A system for treating a vascular region, the system comprising: A slender duct shaft with a distal region; The central cavity is formed within the slender conduit shaft; An ultrasonic therapy core disposed within the central cavity, the ultrasonic therapy core comprising a plurality of axially spaced ultrasonic transducers; The catheter shaft includes a plurality of shielded delivery chambers disposed near the central lumen, the plurality of shielded delivery chambers being configured to deliver microbubbles and / or fluid to a target region; and At least a portion of each of the shielded delivery cavities is configured to protect microbubbles and / or fluid disposed within the shielded delivery cavity from the influence of the plurality of axially spaced ultrasonic transducers.

13. The system of claim 12, wherein the shielded delivery cavity is formed in the conduit shaft.

14. The system according to any one of claims 12 to 13, wherein each of the plurality of axially spaced ultrasonic transducers is defined by a tubular member disposed near the duct axis.

15. The system according to any one of claims 12 to 14, wherein each of the shielded delivery cavities comprises a cavitation.

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