Patent Application
20200109994
The present disclosure relates generally to an ultrasonic catheter and more specifically to an ultrasonic catheter configured to deliver ultrasonic energy and a therapeutic compound to a treatment site.
Several medical applications use ultrasonic energy. For example, U.S. Pat. Nos. 4,821,740, 4,953,565 and 5,007,438 disclose the use of ultrasonic energy to enhance the effect of various therapeutic compounds. An ultrasonic catheter can be used to deliver ultrasonic energy and a therapeutic compound to a treatment site within a patient's body. Such an ultrasonic catheter typically includes an ultrasound assembly configured to generate ultrasonic energy and a fluid delivery lumen for delivering the therapeutic compound to the treatment site.
As taught in U.S. Pat. No. 6,001,069, ultrasonic catheters can be used to treat human blood vessels that have become partially or completely occluded by plaque, thrombi, emboli or other substances that reduce the blood carrying capacity of the vessel. To remove or reduce the occlusion, the ultrasonic catheter is used to deliver solutions containing therapeutic compounds directly to the occlusion site. Ultrasonic energy generated by the ultrasound assembly enhances the effect of the therapeutic compounds. Such a device can be used in the treatment of diseases such as peripheral arterial occlusion, deep vein thrombosis or acute ischemic stroke. In such applications, the ultrasonic energy enhances treatment of the occlusion with therapeutic compounds such as urokinase, tissue plasminogen activator (“tPA”), recombinant tissue plasminogen activator (“rtPA”) and the like. Further information on enhancing the effect of a therapeutic compound using ultrasonic energy is provided in U.S. Pat. Nos. 5,318,014, 5,362,309, 5,474,531, 5,628,728, 6,001,069, 6,210,356 and 7,341,569.
Another use for ultrasonic catheters is in the treatment of pulmonary embolisms. Pulmonary embolisms (“PE”) are caused when a large blood clot obstructs the major blood vessels leading from the heart to the lungs. The victim's heart can be suddenly overwhelmed with the task of pushing blood past this obstruction. About 5% of PEs are classified as massive and can result in rapid heart failure, shock and death without immediate therapy. Such massive PEs have traditionally been treated by a large dose of clot-dissolving drug (i.e., a thrombolytic). However, such treatment can result in unintended bleeding and even fatalities. Up to 40% of PEs are less critical obstructions, often called sub-massive PE. Current treatment protocols include treatment with anti-coagulant medication. Such treatments do not remove the clot but simply prevent the clot from growing larger. Recent studies suggest that failure to remove these sub-massive clots may have long-term adverse consequences including recurrent PE, chronic pulmonary hypertension and death.
In some embodiments, disclosed is an ultrasound catheter that includes a first tubular body having a first longitudinal axis extending centrally through the tubular body, the first tubular body including at least one delivery port extending through a wall of the first tubular body. In some embodiments, the ultrasound catheter includes a second tubular body having a second longitudinal axis extending centrally through the second tubular body, the first and second longitudinal axes being displaced from each other such that an asymmetrical longitudinally extending gap is formed between an outer surface of the second tubular body and an interior surface of the first tubular body. In some embodiments, the ultrasound catheter includes a temperature sensor forming a thermocouple extending longitudinally within the gap between the first tubular body and the second tubular body. In some embodiments, the disclosure includes an inner core positioned within the second tubular body, the inner core comprising at least one ultrasound element. In certain embodiments, the temperature sensor comprises a flexible circuit. In certain embodiments, the temperature sensor comprises a plurality of filament pairs wherein each of the filaments is insulated; and a plurality of thermocouples wherein each of the plurality of thermocouples are formed between each of the plurality of filament pairs.
In some embodiments, disclosed is a method of manufacturing a catheter. In some embodiments, the method includes inserting an inner tubular body into an outer tubular body. In some embodiments, the method includes placing a temperature sensor between the outer and inner tubular body, wherein the temperature sensor is adjacent to an outer surface of the inner tubular body such that the inner tubular body does not extend along the same longitudinal axis a the outer tubular body. In certain embodiments, the temperature sensor comprises a flexible circuit. In certain embodiments, the temperature sensor comprises a plurality of filament pairs wherein each of the filaments is insulated; and a plurality of thermocouples wherein each of the plurality of thermocouples are formed between each of the plurality of filament pairs.
In some embodiments, disclosed is an ultrasound catheter including an elongate inner tubular body. In some embodiments, the ultrasound catheter includes an elongate outer tubular wherein the elongate inner tubular body is positioned within the elongate outer tubular body to form an asymmetrical gap between an outer surface of the inner tubular body and an interior surface of the elongate outer tubular body to form a fluid delivery lumen. In some embodiments, the ultrasound catheter includes a temperature sensor extending along the outer surface of the inner tubular body within the gap. In some embodiments, the ultrasound catheter includes an inner core positioned within the inner tubular body and comprising at least one ultrasound element. In certain embodiments, the temperature sensor comprises a flexible circuit. In certain embodiments, the temperature sensor comprises a plurality of filament pairs wherein each of the filaments is insulated; and a plurality of thermocouples wherein each of the plurality of thermocouples are formed between each of the plurality of filament pairs.
In some embodiments, disclosed is a method of manufacturing a catheter including inserting an inner tubular body into an outer tubular body. In some embodiments, the method of manufacturing includes placing a temperature sensor between the outer and inner tubular body, wherein the temperature sensor is adjacent to an outer surface of the inner tubular body such that the inner tubular body does not extend along the same longitudinal axis a the outer tubular body. In certain embodiments, the temperature sensor comprises a flexible circuit. In certain embodiments, the temperature sensor comprises a plurality of filament pairs wherein each of the filaments is insulated; and a plurality of thermocouples wherein each of the plurality of thermocouples are formed between each of the plurality of filament pairs.
In some embodiments, disclosed is an ultrasound catheter including an elongate inner tubular body. In some embodiments, the ultrasound catheter includes an elongate outer tubular wherein the elongate inner tubular body is positioned within the elongate outer tubular body to form an asymmetrical gap between an outer surface of the inner tubular body and an interior surface of the elongate outer tubular body to form a fluid delivery lumen. In some embodiments, the ultrasound catheter includes a temperature sensor extending along the outer surface of the inner tubular body within the gap. In some embodiments, the ultrasound catheter includes an inner core positioned within the inner tubular body and comprising at least one ultrasound element.
In some embodiments, disclosed is a flexible circuit for a catheter. In some embodiments, the flexible circuit includes a plurality of traces formed on the flexible circuit separated by insulating material. In some embodiments, the plurality of traces includes at least two traces of a first material connected to a single trace of second dissimilar material at different points along a length of the flexible circuit. In some embodiments, a temperature sensor for a catheter comprises a plurality of filament pairs wherein each of the filaments is insulated; and a plurality of thermocouples wherein each of the plurality of thermocouples are formed between each of the plurality of filament pairs.
For purposes of summarizing the invention and the advantages achieved over the prior art, certain objects and advantages of the invention have been described in this application. It is to be understood that not necessarily all such objects or advantages may be achieved in accordance with any particular embodiment of the invention. Thus, for example, those skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught herein without necessarily achieving other objects or advantages as may be taught or suggested herein.
All of these embodiments are intended to be within the scope of the invention herein disclosed. These and other embodiments of the present invention will become readily apparent to those skilled in the art from the following detailed description of the embodiments having reference to the attached figures, the invention not being limited to any particular embodiment(s) disclosed.
Exemplary embodiments of the vascular occlusion treatment system are illustrated in the accompanying drawings, which are for illustrative purposes only. The drawings comprise the following figures, in which like numerals indicate like parts.
As described above, it is desired to provide an ultrasonic catheter also referred to herein as “ultrasound catheter(s)” having various features and advantages. Examples of such features and advantages include the ability to apply ultrasonic energy to a treatment site. In other embodiments, the catheter has the ability to deliver a therapeutic compound to the treatment site. Embodiments of an ultrasonic catheter having certain of these features and advantages are described herein. Methods of using such an ultrasonic catheter are also described herein.
The ultrasonic catheters also referred to herein as “ultrasound catheter(s)” described herein can be used to enhance the therapeutic effects of therapeutic compounds at a treatment site within a patient's body. As used herein, the term “therapeutic compound” refers broadly, without limitation, to a drug, medicament, dissolution compound, genetic material, anti-cancer drug, or any other substance capable of effecting physiological functions. Additionally, any mixture comprising any such substances is encompassed within this definition of “therapeutic compound”, as well as any substance falling within the ordinary meaning of these terms. The enhancement of the effects of therapeutic compounds using ultrasonic energy is described in U.S. Pat. Nos. 5,318,014, 5,362,309, 5,474,531, 5,628,728, 6,001,069 and 6,210,356, the entire disclosures of which are hereby incorporated by herein by reference. Specifically, for applications that treat human blood vessels that have become partially or completely occluded by plaque, thrombi, emboli or other substances that reduce the blood carrying capacity of a vessel, suitable therapeutic compounds include, but are not limited to, an aqueous solution containing Heparin, Uronkinase, Streptokinase, TPA and BB-10153 (manufactured by British Biotech, Oxford, UK).
Certain features and aspects of the ultrasonic catheters disclosed herein may also find utility in applications where the ultrasonic energy itself provides a therapeutic effect. Examples of such therapeutic effects include preventing or reducing stenosis and/or restenosis; tissue ablation, abrasion or disruption; promoting temporary or permanent physiological changes in intracellular or intercellular structures; and rupturing micro-balloons or micro-bubbles for therapeutic compound delivery. Further information about such methods can be found in U.S. Pat. Nos. 5,261,291 and 5,431,663, the entire disclosures of which are hereby incorporated by herein by reference.
The ultrasonic catheters described herein can be configured for applying ultrasonic energy over a substantial length of a body lumen, such as, for example, the larger vessels located in the leg. In other embodiments, the catheter can be configured for treatment of pulmonary embolisms, (“PE”), which can be caused when a large blood clot obstructs the major blood vessels leading from the heart to the lungs. However, it should be appreciated that certain features and aspects of the present disclosure may be applied to catheters configured to be inserted into other vessels or cavities such as the small cerebral vessels, in solid tissues, in duct systems and in body cavities. Additional embodiments that may be combined with certain features and aspects of the embodiments described herein are described in U.S. Patent Publication US2004/0019318, entitled “Ultrasound Assembly For Use With A Catheter” and filed Nov. 7, 2002, the entire disclosure of which is hereby incorporated herein by reference.
As illustrated in
For example, in some embodiments, the proximal region 14 of the exterior tubular body 12 can comprise a material that has sufficient flexibility, kink resistance, rigidity and structural support to push the energy delivery section 18 through the patient's vasculature to a treatment site. Examples of such materials include, but are not limited to, extruded polytetrafluoroethylene (“PTFE”), polyethylenes (“PE”), polyamides and other similar materials. In certain embodiments, the proximal region 14 of the exterior tubular body 12 is reinforced by braiding, mesh or other constructions to provide increased kink resistance and pushability. For example, nickel titanium or stainless steel wires can be placed along or incorporated into the exterior tubular body 12 to reduce kinking.
In some embodiments configured for treating thrombus in the arteries of the leg, the exterior tubular body 12 has an outside diameter between about 0.060 inches and about 0.075 inches (between about 0.15 cm and about 0.19 cm). In another embodiment, the exterior tubular body 12 has an outside diameter of about 0.071 inches (about 0.18 cm). In certain embodiments, the exterior tubular body 12 has an axial length of approximately 106 to 135 centimeters, although other lengths may by appropriate for other applications.
The energy delivery section 18 of the exterior tubular body 12 can include a material that is thinner than the material comprising the proximal region 14 of the exterior tubular body 12 or a material that has a greater acoustic transparency. Thinner materials generally have greater acoustic transparency than thicker materials. Suitable materials for the energy delivery section 18 can include, but are not limited to, high or low density polyethylenes, urethanes, nylons, and the like. In certain modified embodiments, the energy delivery section 18 may be formed from the same material or a material of the same thickness as the proximal region 14.
In certain embodiments, the exterior tubular body 12 can be divided into three sections of varying stiffness. In some embodiments, the first section, can include the proximal region 14, which can have a relatively higher stiffness. The second section, which can be located in an intermediate region between the proximal region 14 and the distal region 15 of the exterior tubular body 12, can have a relatively lower stiffness. This configuration further facilitates movement and placement of the catheter 10. The third section, which can include the energy delivery section 18, can be generally lower in stiffness than the second section in spite of the presence of the ultrasound radiating members 40.
To provide access to the interior of the exterior tubular body 12, a plurality of inlets can be fluidly connected to the proximal region 14 of catheter 10. In some examples, the proximal region 14 of the catheter 10 can include a cooling inlet port 46, a drug inlet port 32, and/or a proximal access port 31. In some embodiments, to provide an electrical connection to the energy delivery section 18, the catheter 10 can further include a cable 45 that can include a connector 101 to the control system 100 (shown in
With continued reference to
In some embodiments, the interior tubular body 13 can include an uneven exterior and/or interior surface that can, as will be discussed in more detail, additional cooling within the device. In some embodiments, the interior tubular body 13 can have a non-circular cross-section. In some embodiments, the interior tubular body 13 can include a plurality of indentations 786 and/or protrusions 787 such that the interior tubular body 13 does not have a circular interior surface and/or exterior surface. Because the diameter of the inner core 706 is less than the diameter of the interior tubular body, in an interior tubular body with a circular interior surface, the inner core 706 could be placed against the interior tubular body 13 such that there could be a relatively large portion with no or minimal gap between the exterior surface of the inner core 706 and the interior surface of the interior tubular body 13 and/or a relatively large portion with no or minimal gap between the exterior of the interior tubular body 13 and the interior of the exterior tubular body 12. This can potentially cause uneven over-heating of the inner core 706. The indentations 786 can therefore ensure that cooling fluid will have room to flow past the inner core 706 and contact more external surfaces of the inner core 706. In a similar manner, drug flowing between the interior tubular body 13 and the exterior tubular body 12 can be more uniformly distributed between the two tubular components as a result of an uneven surface about the exterior of the interior tubular body 13. In some embodiments, the exterior of the interior tubular body 13 can include indentations 788 and/or protrusions 789. In some embodiments, the plurality of indentations 788 and/or protrusions 789 can ensure that the inner core 706 does not cause overheating within the exterior tubular body 12. In some examples, as the indentations 786, 788 and/or protrusions 787, 789 can be of any shape or size, this can reduce manufacturing costs as any imperfection on the inner and/or outer surface of the tubular body 13 would provide additional cooling benefits to the inserted inner core 706. The indentations 786, 788 and/or protrusions 787, 789 can extend longitudinally along the length of the interior tubular body 13. In certain embodiments, the indentations 786, 788 and/or protrusions 787, 789 can extend longitudinally along at least 50% of the length of the interior tubular body 13 and along at least 75% of the length of the interior tubular body 13 and in certain embodiments along at least 90% of the length of the interior tubular body 13. The embodiment of the interior tubular body 13 with indentations 786, 788 and/or protrusions 787, 789 can be used in combination with the temperature sensors described herein and/or used independently to promote uniform cooling.
Turning first to the flexcircuits illustrated in
To form the thermocouple, the flexcircuit 220 includes a plurality of second traces formed of a material different than the first trace 207. Each individual trace of this plurality of second traces extends from the proximal end 230 to a different point along the length of the flexcircuit 220. In some examples, the individual traces of this plurality of second traces are made of copper overlaid on the flexcircuit 220. In the illustrated embodiment, the first trace is Constantan and the plurality of second traces are formed from copper. In other embodiments, the first and second materials can be a different combination of materials. For example, the first material can be Alumel (consisting of approximately 95% nickel, 2% manganese, 2% aluminum and 1% silicon) and the second material can be Chromel (90% nickel and 10% chromium) as can be found in a Type K thermocouple or other combinations of dissimilar materials. In one example, the flexcircuit 220 can include a trace 201 that extends from the proximal end 230 of the flexcircuit 220 to a joint 211 at the distal end 240 of the flexcircuit 220. Similarly, the flexcircuit 220 can include one or more of any of the following traces: trace 201 that extends from the proximal end 230 to a joint 211 close to a distal end of the flexcircuit 220, trace 202 that extends from the proximal end 230 to a joint 212, trace 203 that extends from the proximal end 230 to a joint 213, trace 204 that extends from the proximal end 230 to a joint 214, trace 205 that extends from the proximal end 230 to a joint 215, and trace 206 that extends from the proximal end 230 to a joint 216 closer to a proximal end of the flexcircuit 220. In some examples, the plurality of joints (e.g. joint 211, joint 212, joint 213, joint 214, joint 215, and joint 216) allows the temperature to be taken along several points along the length of the flexcircuit 220. In some variants, this can help to measure the temperature of the ultrasonic catheter along the entire length of the device or a portion of the device (e.g., a portion of the device that includes the ultrasound elements described below). In modified embodiments, the traces 201-206 and joints 211-216 can be arranged in different orders or configurations.
When temperature differential is experienced by the different conductors (e.g., between one of the traces 201-206 and the first trace 207), it produces a voltage when the temperature of one of the spots differs from the reference temperature at other parts of the circuit. In this manner, temperatures along the flexcircuit 220 can be measured by measuring the voltages between one of the traces 201-206 and the first trace 207. The illustrated preferred embodiment of
In some embodiments, the flexcircuit 220 can be of variable length and can be configured to run the entire length or a portion of the catheter 10. Similarly, to measure temperature along the length of the flexcircuit 220, the distance between the joints 211-216 can be varied for the catheter 10. In the one embodiment, the flexcircuit 220 can have a length l1 from proximal end 230 to distal end 240 of about 115 cm. In some embodiments, the distance between each of the joints 211-216 (e.g. length l2, length l3, length l4, length l5, length l6) can be approximately 10 cm. In additional embodiments, the distance between each of the joints 211-216 can be between 1.0 cm and 50.0 cm depending upon the number of joints and the desired overall length of the flexcircuit 220. The distance between the joints 211-216 need not be uniform in certain embodiments. As mentioned above, in one arrangement, the joints are positioned generally along the length of the catheter in which the ultrasound elements are positioned such that the temperature of the catheter around the ultrasound elements can be monitored. Accordingly, in the illustrated embodiment the joints 211, 212, 213, 214, 215, 216 are positioned in the energy delivery section 18 of the exterior tubular body 12.
The flexcircuit 320 can include a first material trace 307 that runs parallel to the length of the flexcircuit 320. In order to measure temperature at a specific point along the flexcircuit 320, each of the traces (e.g. trace 301, trace 302, trace 303, trace 304, trace 305, and trace 306) runs a varied distance along the flexcircuit 320. Traces (e.g. trace 301, trace 302, trace 303, trace 304, trace 305, and trace 306) can be made of a second material different from the first material. As with the embodiment of
In certain embodiments, the temperature sensor 20 can be a ribbon thermocouple composed of a plurality of wires or that are coupled together. For example,
As shown in
In some examples, the ribbon thermocouple 500 can be configured to form a plurality of thermocouples along the length of the ribbon thermocouple 500 from the proximal end 550 to the distal end 560. In some embodiments, each of the thermocouples can be formed by stripping adjacent filaments of insulation and soldering the exposed conductor 520 together to form a thermocouple joint. As illustrated in
In some examples, the two filaments of the thermocouple junction are formed of different materials. In some embodiments, one of the two filaments of the thermocouple junction is formed of copper and one of the two filaments of the thermocouple junction is formed of constantan.
As shown in
As shown in
In some examples, the ribbon thermocouple 600 can be configured to form a plurality of thermocouples along the length of the temperature sensor 600 from the proximal end 650 to the distal end 660. In some embodiments, each of the thermocouples can be formed by stripping adjacent filaments of insulation and soldering the exposed conductor 520 together to form a thermocouple joint. As illustrated in
In some examples, the two filaments of the thermocouple junction are formed of different materials. In some embodiments, one of the two filaments of the thermocouple junction is formed of copper and one of the two filaments of the thermocouple junction is formed of constantan.
As shown in
The illustrated embodiments of
In some embodiments, the ribbon thermocouple design of
Turning back to
For example,
Unlike the hub described in
The proximal hub 60′ also includes a plurality of inlets to provide fluid communication with the interior of the catheter 10. The proximal hub 60′ can have a proximal access port 31′. In some examples, the proximal hub 60′ can include a second barb inlet 75′ which can provide fluid communication to the gap 52 and a third barb inlet 63′ that can provide access to the central lumen 51. In the embodiment illustrated in
The proximal hub 60′ can be secured to the nosecone 70′ through a plurality of components. As illustrated in
With continued reference to
As discussed above, a plurality of components may be attached to the inlets of the distal hub 65 and proximal hub 60 to be in fluid communication with the interior of the exterior tubular body 12. As illustrated in
In order to secure the aforementioned components in the proximal region 14 of the catheter 10, the catheter 10 can include a housing structure to secure the fluid line 91 and cooling fluid line 92 to the inlets of the distal hub 65 and proximal hub 60. In some examples, as illustrated in
As noted above, in some embodiments, the arrangement of the exterior tubular body 12 and the interior tubular body 13 can be configured into an asymmetrical arrangement so as to accommodate the temperature sensor 20. As illustrated in
In some embodiments, the central lumen 51 has a minimum diameter greater than about 0.030 inches (greater than about 0.076 cm). In other embodiments, the central lumen 51 has a minimum diameter greater than about 0.037 inches (greater than about 0.094 cm), although other dimensions may be used in other applications. As described above, the central lumen 51 can extend through the length of the exterior tubular body 12. As illustrated in
The central lumen 51 can be configured to receive an inner core 34 comprising a plurality of ultrasound radiating members extending along a length of the ultrasound catheter.
In some embodiments, the hub 745 of the ultrasonic catheter 700 can be composed of a plurality of nested components that are sealed together. As illustrated in
Turning first to
In some embodiments, the cap 710 can include an internal taper 714 that reduces in diameter. As shown in
In some examples, as shown in
Turning next to
In some embodiments, the manifold body 730 can include an internal taper 733 that reduces in diameter. As shown in
As noted above, the hub 745 can include a number of openings to allow access to the interior of the exterior tubular body 12 and the interior tubular body 13 as shown in
In some examples, as illustrated in
In some embodiments, as illustrated in
In some embodiments, the hub 845 of the ultrasonic catheter 800 can be composed of a plurality of nested components that are secured together. In some examples, the various components of the hub 845 can be composed of a polycarbonate. As will be discussed in more detail below, the hub 845 can include an external overmold that provides an easy and secure way of attaching the various components of the hub 845. As illustrated in
Turning first to
In some embodiments, the manifold cap 810 can include an internal taper 812 that reduces in diameter. As shown in
In some examples, as shown in
Turning next to
In some embodiments, the proximal end 828 of the distal manifold 820 can be configured to engage with and secure the interior tubular body 13. In some embodiments, the distal manifold 820 can include an internal taper 823 that reduces in diameter. As shown in
As noted above, the hub 845 can include a number of openings to allow access to the interior of the exterior tubular body 12 and the interior tubular body 13 as shown in
In some examples, as illustrated in
In some embodiments, as illustrated in
As discussed above, in some embodiments, the hub 845 can include an overmold 860. In some examples, the overmold 860 can be composed of a co-polyester. In some embodiments, the overmold 860 can be composed of a polyamide. The overmold 860 can be configured to seal and secure the various components of the hub 845.
Details and various embodiments of the inner core 34 and its operation of can be found in several patents and patent applications filed by EKOS Corporation of Bothell, Wash. including U.S. Pat. No. 7,220,239 and U.S. Patent Publication No. 2008/0171965, which are hereby incorporated by reference in their entirety.
As shown in the cross-section illustrated in
Still referring to
In some embodiments, the ultrasound assembly 42 comprises a plurality of ultrasound radiating members 40 that are divided into one or more groups. For example,
In some embodiments, the ultrasound assembly 42 comprises five or less (i.e., one, two, three, four, or five) ultrasound radiating members 40. The ultrasound radiating members 40 may be divided into one or more groups as described above. The reduced or limited number of ultrasound radiating members 40 can allow the ultrasound assembly 42 to be driven at a higher power.
As used herein, the terms “ultrasonic energy”, “ultrasound” and “ultrasonic” are broad terms, having their ordinary meanings, and further refer to, without limitation, mechanical energy transferred through longitudinal pressure or compression waves. Ultrasonic energy can be emitted as continuous or pulsed waves, depending on the requirements of a particular application. Additionally, ultrasonic energy can be emitted in waveforms having various shapes, such as sinusoidal waves, triangle waves, square waves, or other wave forms. Ultrasonic energy includes sound waves. In certain embodiments, the ultrasonic energy has a frequency between about 20 kHz and about 20 MHz. For example, in one embodiment, the waves have a frequency between about 500 kHz and about 20 MHz. In another embodiment, the waves have a frequency between about 1 MHz and about 3 MHz. In yet another embodiment, the waves have a frequency of about 2 MHz. The average acoustic power is between about 0.01 watts and 300 watts. In one embodiment, the average acoustic power is about 16 watts.
As used herein, the term “ultrasound radiating member” refers to any apparatus capable of producing ultrasonic energy. For example, in one embodiment, an ultrasound radiating member comprises an ultrasonic transducer, which converts electrical energy into ultrasonic energy. A suitable example of an ultrasonic transducer for generating ultrasonic energy from electrical energy includes, but is not limited to, piezoelectric ceramic oscillators. Piezoelectric ceramics typically comprise a crystalline material, such as quartz, that changes shape when an electrical current is applied to the material. This change in shape, made oscillatory by an oscillating driving signal, creates ultrasonic sound waves. In other embodiments, ultrasonic energy can be generated by an ultrasonic transducer that is remote from the ultrasound radiating member, and the ultrasonic energy can be transmitted, via, for example, vibration through a wire that is coupled to the ultrasound radiating member.
Still referring to
Referring now to
Referring still to
In a modified embodiment, such as illustrated in
One of ordinary skill in the art will recognize that the wiring arrangement described above can be modified to allow each group G1, G2, G3, G4, G5 to be independently powered. Specifically, by providing a separate power source within the control system 100 for each group, each group can be individually turned on or off, or can be driven with an individualized power. This provides the advantage of allowing the delivery of ultrasonic energy to be “turned off” in regions of the treatment site where treatment is complete, thus preventing deleterious or unnecessary ultrasonic energy to be applied to the patient.
The embodiments described above, and illustrated in
In some embodiments, the ultrasound radiating members 40 comprise rectangular lead zirconate titanate (“PZT”) ultrasound transducers. In some embodiments, the ultrasound transducer may have dimensions of about 0.017 inches by about 0.010 inches by about 0.080 inches (about 0.043 cm by about 0.025 cm by about 0.20 cm). In other embodiments, other configuration may be used. For example, disc-shaped ultrasound radiating members 40 can be used in other embodiments. In an embodiment, the common wire 108 comprises copper, and is about 0.005 inches (about 0.01 cm) thick, although other electrically conductive materials and other dimensions can be used in other embodiments. Lead wires 110 can comprise 36 gauge electrical conductors, while positive contact wires 112 can be 42 gauge electrical conductors. However, one of ordinary skill in the art will recognize that other wire gauges can be used in other embodiments.
As described above, suitable frequencies for the ultrasound radiating member 40 include, but are not limited to, from about 20 kHz to about 20 MHz. In one embodiment, the frequency is between about 500 kHz and 20 MHz, and in another embodiment 1 MHz and 3 MHz. In yet another embodiment, the ultrasound radiating members 40 are operated with a frequency of about 2 MHz.
In some embodiments, as illustrated in
In some examples, the configuration of the interior tubular body 13 and temperature sensor 20 can provide a manufacturing benefit as it allows for the construction of the catheter 10 by simply inserting the interior tubular body 13 and temperature sensor 20 into the exterior tubular body 12. This can allow the gap 52 to form between the exterior surface of the interior tubular body 13 and the interior surface of the exterior tubular body 12. In some embodiments, the size, location, and geometry of the fluid delivery ports 58 can be selected to provide uniform fluid flow from the fluid delivery ports 58 to the treatment site. For example, in one embodiment, the fluid delivery ports 58 closer to the proximal region of the energy delivery section 18 have smaller diameters than fluid delivery ports 58 closer to the distal region of the energy delivery section 18, thereby allowing uniform delivery of fluid across the entire energy delivery section 18. The configuration of the interior tubular body 13 can also provide better kink resistance and can potentially reduce the ultrasound attenuation. In some embodiments where the fluid delivery ports 58 have similar sizes along the length of the exterior tubular body 12, the fluid delivery ports 58 have a diameter between about 0.0005 inches to about 0.0050 inches (between about 0.001 cm to about 0.013 cm). In another embodiment in which the size of the fluid delivery ports 58 changes along the length of the exterior tubular body 12, the fluid delivery ports 58 have a diameter between about 0.001 inches to about 0.005 inches (between about 0.002 to about 0.01 cm) in the proximal region of the energy delivery section 18, and between about 0.0020 inches to about 0.005 inches (between about 0.005 cm to 0.01 about cm) in the distal region of the energy delivery section 18. The increase in size between fluid delivery ports 58 depends on the material composition of the exterior tubular body 12, and on the gap 52. In some embodiments, the fluid delivery ports 58 can be created in the exterior tubular body 12 by punching, drilling, burning, or ablating (e.g. with a laser), or by any other suitable methods. The drug or therapeutic compound flowing along the length of the exterior tubular body 12 can be increased by increasing the density of the number of fluid delivery ports 58 toward the distal region 15 of the exterior tubular body 12.
It should be appreciated that it may be desirable to provide non-uniform fluid flow from the fluid delivery ports 58 to the treatment site. In such embodiment, the size, location and geometry of the fluid delivery ports 58 can be selected to provide such non-uniform fluid flow.
Referring still to
In some embodiments, the inner core 34 can be rotated or moved within the interior tubular body 13. Specifically, movement of the inner core 34 can be accomplished by maneuvering the proximal hub 37 while holding the backend hub 33 stationary. The inner core outer body 35 is at least partially constructed from a material that provides enough structural support to permit movement of the inner core 34 within the interior tubular body 13 without kinking of the interior tubular body 13 without kinking of the interior tubular body 13. Additionally, the inner core outer body 35 can include a material having the ability to transmit torque. Suitable materials for the outer body 35 can include, but are not limited to, polymides, polyesters, polyurethanes, thermoplastic elastomers and braided polyimides.
In one embodiment, the fluid delivery lumen 30 and the cooling fluid lumen 44 are open at the distal end of the exterior tubular body 12, thereby allowing the drug or therapeutic compound and the cooling fluid to pass into the patients' vasculature at the distal exit port. Or, if desired, the fluid delivery lumen 30 can be selectively occluded at the distal end of the exterior tubular body 12, thereby providing additional hydraulic pressure to drive the therapeutic compound out of the fluid delivery ports 58. In either configuration, the inner core 34 can prevented from passing through the distal exit port by providing the inner core 34 with a length that is less than the length of the tubular body. In other embodiments, a protrusion is formed on the internal side of the tubular body in the distal region 15, thereby preventing the inner core 34 from passing through the distal exit port.
In still other embodiments, the catheter 10 further includes an occlusion device (not shown) positioned at the distal exit port 29. The occlusion device can have a reduced inner diameter that can accommodate a guidewire, but that is less than the inner diameter of the central lumen 51. Thus the inner core 34 is prevented from extending through the occlusion device and out the distal exit port 29. For example, suitable inner diameters for the occlusion device include, but are not limited to, about 0.005 inches to about 0.050 inches (about 0.01 cm to about 0.13 cm). In other embodiments, the occlusion device has a closed end, thus preventing cooling fluid from leaving the catheter 10, and instead recirculating to the proximal region 14 of the exterior tubular body 12. These and other cooling fluid flow configurations permit the power provided to the ultrasound assembly 42 to be increased in proportion to the cooling fluid flow rate. Additionally, certain cooling fluid flow configurations can reduce exposure of the patient's body to cooling fluids.
In certain embodiments, as illustrated in
In other embodiments, each temperature sensor 20 is independently wired. In such embodiments, 2n wires run through the exterior tubular body 12 to independently sense the temperature at n independent temperature sensor 20.
The feedback control system 68 can include an energy source 70, power circuits 72 and a power calculation device 74 that is coupled to the ultrasound radiating members 40. A temperature measurement device 76 can coupled to the temperature sensor 20 in the exterior tubular body 12. A processing unit 78 can be coupled to the power calculation device 74, the power circuits 72 and a user interface and display 80.
In operation, the temperature at each temperature sensor 20 can be determined by the temperature measurement device 76. The processing unit 78 receives each determined temperature from the temperature measurement device 76. The determined temperature can then be displayed to the user at the user interface and display 80.
The processing unit 78 comprises logic for generating a temperature control signal. The temperature control signal can be proportional to the difference between the measured temperature and a desired temperature. The desired temperature can be determined by the user (at set at the user interface and display 80) or can be preset within the processing unit 78.
The temperature control signal can be received by the power circuits 72. In some embodiments, the power circuits 72 can be configured to adjust the power level, voltage, phase and/or current of the electrical energy supplied to the ultrasound radiating members 40 from the energy source 70. For example, when the temperature control signal is above a particular level, the power supplied to a particular group of ultrasound radiating members 40 can be reduced in response to that temperature control signal. Similarly, when the temperature control signal is below a particular level, the power supplied to a particular group of ultrasound radiating members 40 can be increased in response to that temperature control signal. After each power adjustment, the processing unit 78 can be configured to monitor the temperature sensor 20 and produces another temperature control signal which is received by the power circuits 72.
The processing unit 78 can further include safety control logic. The safety control logic detects when the temperature at a temperature sensor 20 has exceeded a safety threshold. The processing unit 78 can then provide a temperature control signal which causes the power circuits 72 to stop the delivery of energy from the energy source 70 to that particular group of ultrasound radiating members 40.
Because, in certain embodiments, the ultrasound radiating members 40 are mobile relative to the temperature sensor 20, it can be unclear which group of ultrasound radiating members 40 should have a power, voltage, phase and/or current level adjustment. Consequently, each group of ultrasound radiating member 40 can be identically adjusted in certain embodiments. In a modified embodiment, the power, voltage, phase, and/or current supplied to each group of ultrasound radiating members 40 is adjusted in response to the temperature sensor 20 which indicates the highest temperature. Making voltage, phase and/or current adjustments in response to the temperature sensed by the temperature sensor 20 indicating the highest temperature can reduce overheating of the treatment site.
The processing unit 78 can also receive a power signal from a power calculation device 74. The power signal can be used to determine the power being received by each group of ultrasound radiating members 40. The determined power can then be displayed to the user on the user interface and display 80.
As described above, the feedback control system 68 can be configured to maintain tissue adjacent to the energy delivery section 18 below a desired temperature. For example, it can be generally desirable to prevent tissue at a treatment site from increasing more than 6° C. As described above, the ultrasound radiating members 40 can be electrically connected such that each group of ultrasound radiating members 40 generates an independent output. In certain embodiments, the output from the power circuit maintains a selected energy for each group of ultrasound radiating members 40 for a selected length of time.
The processing unit 78 can comprise a digital or analog controller, such as a computer with software. When the processing unit 78 is a computer it can include a central processing unit (“CPU”) coupled through a system bus. As is well known in the art, the user interface and display 80 can comprise a mouse, a keyboard, a disk drive, a display monitor, a nonvolatile memory system, or any another. In some embodiments, the bus can be coupled to a program memory and a data memory.
In lieu of the series of power adjustments described above, a profile of the power to be delivered to each group of ultrasound radiating members 40 can be incorporated into the processing unit 78, such that a preset amount of ultrasonic energy to be delivered is pre-profiled. In such embodiments, the power delivered to each group of ultrasound radiating members 40 can then be adjusted according to the preset profiles.
The ultrasound radiating members can be operated in a pulsed mode. For example, in one embodiment, the time average electrical power supplied to the ultrasound radiating members can be between about 0.1 watts and 2 watts and can be between about 0.5 watts and 1.5 watts. In other embodiments, the time average electrical power supplied to the ultrasound radiating members is between about 0.001 watts and about 5 watts and can be between about 0.05 watts and about 3 watts. In some embodiments, the time average electrical power can be approximately 0.6 watts or 1.2 watts to a pair of ultrasound radiating members. In other embodiments, the time average electrical power over treatment time can be approximately 0.45 watts or 1.2 watts to a pair of ultrasound radiating members.
The duty cycle can be between about 1% and 50%. In some embodiments, the duty cycle can be between about 5% and 25%. In certain embodiments, the duty ratio can be approximately 7.5% or 15%. In other embodiments, the duty cycle can be between about 0.01% and about 90% and can be between about 0.1% and about 50%. In certain embodiments, the duty ratio can be approximately 7.5%, 15% or a variation between 1% and 30%. In some embodiments, the pulse averaged power to a pair of ultrasound radiating members can be between about 0.1 watts and 20 watts and can further be between approximately 5 watts and 20 watts. In certain embodiments, the pulse averaged power to a pair of ultrasound radiating members can be approximately 8 watts and 16 watts. In some embodiments, the pulse averaged electrical power to a pair of ultrasound radiating members can be between about 0.01 watts and about 20 watts and can be between approximately 0.1 watts and 20 watts. In other embodiments, the pulse averaged electrical power to a pair of ultrasound radiating members is approximately 4 watts, 8 watts, 16 watts, or a variation of 1 to 8 watts. The amplitude during each pulse can be constant or varied.
As described above, the amplitude, pulse width, pulse repetition frequency, average acoustic pressure or any combination of these parameters can be constant or varied during each pulse or over a set of portions. In a non-linear application of acoustic parameters the above ranges can change significantly. Accordingly, the overall time average electrical power over treatment time may stay the same but not real-time average power.
In some embodiments, the pulse repetition rate can be between about 5 Hz and 150 Hz and can further be between about 10 Hz and 50 Hz. In some embodiments, the pulse repetition rate is approximately 30 Hz. In other embodiments, the pulse repetition can be between about 1 Hz and about 2 kHz and more can be between about 1 Hz and about 50 Hz. In certain embodiments, the pulse repetition rate can be approximately 30 Hz, or a variation of about 10 to about 40 Hz. The pulse duration can be between about 1 millisecond and 50 milliseconds and can be between about 1 millisecond and 25 milliseconds. In certain embodiments, the pulse duration can be approximately 2.5 milliseconds or 5 milliseconds. In other embodiments, the pulse duration or width can be between about 0. 5 millisecond and about 50 milliseconds and can be between about 0.1 millisecond and about 25 milliseconds. In certain embodiments, the pulse duration can be approximately 2.5 milliseconds, 5 or a variation of 1 to 8 milliseconds. In certain embodiments, the average acoustic pressure can be between about 0.1 to about 20 MPa or in another embodiment between about 0.5 or about 0.74 to about 1.7 MPa. In one particular embodiment, the transducers can be operated at an average power of approximately 0.6 watts, a duty cycle of approximately 7.5%, a pulse repetition rate of 30 Hz, a pulse average electrical power of approximately 8 watts and a pulse duration of approximately 2.5 milliseconds. In one particular embodiment, the transducers can be operated at an average power of approximately 0.45 watts, a duty cycle of approximately 7.5%, a pulse repetition rate of 30 Hz, a pulse average electrical power of approximately 6 watts and a pulse duration of approximately 2.5 milliseconds. The ultrasound radiating member used with the electrical parameters described herein can have an acoustic efficiency greater than 50%. In some embodiments, the acoustic efficiency can be greater than 75%. The ultrasound radiating member can be formed a variety of shapes, such as, cylindrical (solid or hollow), flat, bar, triangular, and the like. The length of the ultrasound radiating member can be between about 0.1 cm and about 0.5 cm. The thickness or diameter of the ultrasound radiating members can be between about 0.02 cm and about 0.2 cm.
As illustrated in
As illustrated in
As illustrated in
In a certain embodiment, the ultrasound assembly 42 comprises sixty ultrasound radiating members 40 spaced over a length of approximately 30 to 50 cm. In such embodiments, the catheter 10 can be used to treat an elongate clot 90 without requiring movement of or repositioning of the catheter 10 during the treatment. However, in some embodiments, the inner core 34 can be moved or rotated within the catheter 10 during the treatment. Such movement can be accomplished by maneuvering the proximal hub 37 of the inner core 34 while holding the backend hub 33 stationary.
Referring again to
The cooling fluid can be delivered before, after, during or intermittently with the delivery of ultrasonic energy. Similarly, the therapeutic compound can be delivered before, after, during or intermittently with the delivery of ultrasonic energy. Consequently, the steps illustrated in
In some embodiments, the ultrasonic catheter 10 can be configured to be introduced into the major blood vessels leading from the heart to the lungs (e.g., the pulmonary artery). In one embodiment of use, femoral venous access may be used to place the ultrasonic catheter 10 into such vessels. In such embodiments, the ultrasonic catheter 10 can be advanced through femoral access site, through the heart and into the pulmonary artery. The dimensions of the ultrasonic catheter 10 are adjusted based on the particular application for which the ultrasonic catheter 10 is to be used.
As noted above, the ultrasound catheter 10 can also be used for treating PE. The ultrasound catheter 10 can be introduced into a patient's pulmonary artery over a guidewire. The distal region 15 of the ultrasound catheter 10 is then advanced to the treatment site within the pulmonary artery. The ultrasound energy delivery section 18 of the ultrasound catheter can be positioned across the treatment site using fluoroscopic guidance via radiopaque marker located near the proximal end and the distal end of the ultrasound energy delivery section 18. Once the ultrasound catheter 10 is successfully placed, the guidewire may be removed from the ultrasound catheter 10. In the embodiments depicted in
The thrombolytic drug can then be delivered to the treatment site through at least one fluid delivery lumen 30. In some embodiments, a plurality of fluid delivery ports 58 is in fluid communication with the fluid delivery lumen 30 can be located on the ultrasound catheter at the ultrasound energy delivery section 18. The drug can be infused through the fluid delivery ports 58 to the treatment site.
The ultrasound energy may be delivered to the treatment site simultaneously or intermittently with the infusion of the thrombolytic drug. In some embodiments, the ultrasound energy is emitted to the treatment site prior to the thrombolytic drug being delivered. In some embodiments, the thrombolytic drug is delivered to the treatment site prior to the ultrasound energy being emitted. The ultrasound energy may be emitted according to the manner described above. In some embodiment, the power parameter and the physiological parameter of at least one ultrasound radiating member 40 may be varied as described above.
In some embodiments, the elongate inner core 34 may comprise five or less (i.e., one, two, three, four, or five) ultrasound radiating members 40. In some variants, by limiting the number of the ultrasound radiating members 40, it is can be possible to drive the ultrasound radiating members at a higher power for PE treatments.
High intensity ultrasound catheter may also be especially effective in treating pulmonary embolism. In some embodiments, the size of one or more ultrasound radiating members 40 positioned in the elongate inner core 34 can be increased to generate high intensity ultrasound. In other words, larger ultrasound radiating members can be used for this purpose. In some embodiments, positioning the ultrasound radiating members less than 1 cm apart can result in higher intensity ultrasound output.
Without being bound to the theory, the ultrasound can prepare the clot by unwinding the fibrin strands and increasing the permeability of the clot. Acoustic pressure waves and micro-streaming force the delivered drug into the clot, quickly permeating the clot with drug. As the drug is absorbed into the clot it binds with exposed plasminogen receptor sites. Once bound in the clot, the drug is no longer in free circulation, does not pass through the liver and is not metabolized.
In some embodiments, recombinant tissue plasminogen activator (rt-PA or Actilyse®) can be used with the ultrasound catheter 10 for the treatment of pulmonary embolism. The effective infusion dosage may range from about 0.12 mg/hr to about 2 mg/hr, from about 0.2 mg/hr to about 1.5 mg/hr, from about 0. 5 mg/hr to about 1.5 mg/hr, or from about 1 mg/hr to about 2 mg/hr. The rt-PA maximum total infusion dose may be from about 10 mg to about 30 mg, from about 10 mg to about 20 mg, or about 25 mg. In some embodiment, as rt-PA is infused at a rate of about 1 mg/hr to about 2 mg/hr for about 3 to about 5 hours, then the infusion rate is decreased to about 0.5 mg/hr for 10 hours. In some embodiments, rt-PA is infused at a rate of about 1 mg/hr to about 2 mg/hr for about 5 hours, and then the infusion rate is decreased to about 0.5 mg/hr for 10 hours.
Other potential drugs that may be used with the ultrasound catheter for treating pulmonary embolism may include fibrinolytic compounds such as urokinase (Abbokinase®, Abbott laboratories, USA), streptokinase (Streptase®, Behringwerke AG), and reteplase (Retavase™, Centocor, Inc.). The enzymatic activity and stability of these fibrinolytics (including rt-PA) are not changed after exposure to therapeutic ultrasound.
In general, digital angiographic equipment is used to aid the performance of the ultrasound catheter treatment procedure. Continuous invasive pressure monitoring and ECG-monitoring can be used for obtaining baseline hemodynamic parameters, including heart rate, right atrial, right ventricular, and pulmonary artery pressures, as well as the mixed-venous oxygen saturation from the pulmonary artery. A systemic arterial blood pressure and a systemic oxygen saturation can also be measured if an arterial line is in place. Otherwise, the systemic cuff blood pressure is measured and the oxygen saturation is obtained by pulse oximetry. In one embodiment, a blood pressure sensor is integrated into the ultrasound catheter.
In some embodiments, a feedback control loop configured to monitor the baseline hemodynamic parameters and/or mixed-venous oxygen saturation can be integrated into the control system 100. The output power of the energy source can then be adjusted according to the readings. A physician can override the closed or open loop system if so desired.
In some embodiments, an unilateral filling defect in one main or proximal lower lobe pulmonary artery by contrast-enhanced chest CT indicates that only one ultrasound catheter is to be placed into the pulmonary artery. In case of bilateral filling defect is detected in both main or proximal lower lobe pulmonary arteries by contrast-enhancing chest CT, two ultrasound catheters may be placed.
As noted above, in some embodiments, femoral venous access may be used for placing the ultrasound catheter in the pulmonary arteries. For example, a 6F introducer sheath is inserted in the common femoral vein. An exchange-length 0.035-inch (0.089-cm) angled guidewire, for example the Terumo soft wire, may be used for probing the embolic occlusion under fluoroscopy. A 5F standard angiographic catheter, such as a multipurpose catheter or pigtail catheter or any other pulmonary angiographic catheter may be used with small manual contrast injections for localizing the embolic occlusion and for positioning the catheter such that the energy delivery section 18 of the ultrasound catheter spans the thrombus. If the distal extent of the embolus is not visible angiographically or if it is difficult to probe the embolic occlusion, a 4F Terumo glide catheter may be used for obtaining very small selective contrast injections beyond the presumed thrombotic occlusion after transiently removing the 0.035 wire. After the wire is successfully placed beyond the thrombotic occlusion in a lower lobe segmental branch, the angiographic catheter is exchanged for the ultrasound catheter.
Finally, in embodiments wherein the ultrasound catheter including elongate inner core with ultrasound catheter (as shown in
After about 12 to about 15 hours of drug infusion, the rt-PA infusion can be replaced with heparinized saline infusion (about 1 μg/ml) at an infusion rate of 5 ml/hr. Sometime between about 16 and about 24 hours after the start of the rt-PA infusion, follow-up hemodynamic measurements (heart rate, systemic arterial pressure, right atrial, right ventricular and pulmonary artery pressures, mixed venous and pulse oximetric oxygen saturations, cardiac output, pulmonary vascular resistance) and controlled removal of the ultrasound catheter can be performed. The decision on the exact duration of the ultrasound-assisted thrombolysis infusion is at the discretion of the physician, but in one embodiment it is recommended to continue the treatment for 15 hours (or until 20 mg of rt-PA has been delivered) if well tolerated by the patient.
In certain embodiments, it can be beneficial to keep the catheter centered in the pulmonary artery during the treatment process. For example, centering the ultrasound radiating member 40 in the pulmonary artery may improve the uniform exposure at the treatment site. In some embodiments, the ultrasound catheter 10 also includes a centering mechanism for keeping the catheter centered during the treatment. In some embodiments, the centering mechanism of the catheter 10 can be provided with one or more balloons disposed around the catheter 10 toward the distal region 15.
As described above, in some embodiments, the ultrasound assembly 42 comprises a plurality of ultrasound radiating members 40 that are divided into one or more groups. For example,
In the embodiment of
The wiring arrangement described above can be modified to allow each group G1, G2, G3, G4, G5 to be independently powered. Specifically, by providing a separate power source within the control system 100 for each group, each group can be individually turned on or off, or can be driven with an individualized power. This provides the advantage of allowing the delivery of ultrasonic energy to be “turned off” in regions of the treatment site where treatment is complete, thus preventing deleterious or unnecessary ultrasonic energy to be applied to the patient.
The embodiments described above, and illustrated in
Method for Assembling a Catheter with a Temperature Sensor
As discussed above, the configuration of the temperature sensor 20 in the exterior tubular body 12 can provide for ease of assembly and manufacturability. In one aspect, the disclosure resides in a method of manufacturing a catheter comprising a flexible circuit and/or a ribbon thermocouple according to any of the embodiments described herein. In a particular embodiment of the disclosure, the flexible circuit is configured to form a thermocouple. In a particular embodiment of the disclosure, the thermocouple ribbon is configured to form a thermocouple.
The method for assembling a catheter with flex circuit thermocouple and/or thermocouple ribbon can first include block 410 which describes first inserting the interior tubular body 13 into the exterior tubular body 12. In some embodiments, the interior tubular body 13 can be inserted into the exterior tubular body 12 such that the outside surface of the interior tubular body 13 contacts the inside surface of the exterior tubular body 12. This can form an asymmetrical space within the exterior tubular body 12 to accommodate a temperature sensor 20.
Next, the method can include block 420 which describes inserting the flexcircuit temperature sensor 20 or and/or thermocouple ribbon 500, 600 through the first barb inlet 69 of the distal hub 65. As described above, the temperature sensor 20 can be the flexcircuit 220 of
Once inserted, the temperature sensor 20 can be attached to the proximal and distal ends of the interior tubular body 13 as discussed in block 430 and block 440. The attachment of the temperature sensor 20 to the interior tubular body 13 can be done using an adhesive or a heat shrink.
At block 450, the remaining components of the catheter 10 are assembled. For example, in the catheter 10 described above,
Once the catheter 10 has been assembled, the method can include block 460 which describes attaching the fluid lines (e.g. fluid line 91 and cooling fluid line 92) to the catheter. As shown above, the fluid line 91 can be attached to the second barb inlet 75 while the cooling fluid line 92 is attached to the barb inlet 63.
To attach the temperature sensor 20 to an electrical source, block 470 describes connecting the temperature sensor 20 to a cable assembly. As illustrated in
The disclosure includes the following additional embodiments:
Embodiment 1. An ultrasound catheter comprising:
a first tubular body having a first longitudinal axis extending centrally through the tubular body, the first tubular body including at least one delivery port extending through a wall of the first tubular body;
a second tubular body having a second longitudinal axis extending centrally through the second tubular body, the first and second longitudinal axes being displaced from each other such that an asymmetrical longitudinally extending gap is formed between an outer surface of the second tubular body and an interior surface of the first tubular body;
a flexible circuit forming a thermocouple extending longitudinally within the gap between the first tubular body and the second tubular body; and
an inner core positioned within the second tubular body, the inner core comprising at least one ultrasound element.
Embodiment 2: The ultrasound catheter of Embodiment 1, wherein the flexible circuit positioned in the widest portion of the asymmetrical gap.
Embodiment 3: The ultrasound catheter of any one of Embodiments 1-2, wherein the flexible circuit extends along the length of the first tubular body.
Embodiment 4: The ultrasound catheter of any one of Embodiments 1-3, wherein the flexible circuit is adjacent to an outer surface of the second tubular body.
Embodiment 5: The ultrasound catheter of any one of Embodiments 1-4, wherein the ultrasound catheter comprises a first fluid injection port in fluid communication with the gap.
Embodiment 6: The ultrasound catheter of any one of Embodiments 1-5, wherein the apparatus further comprises a second fluid injection port in fluid communication with an interior of the second tubular body.
Embodiment 7: The ultrasound catheter of any one of Embodiments 1-6, wherein the flexible circuit is configured to measure temperature at different points along the length of ultrasound catheter.
Embodiment 8: The ultrasound catheter of any one of Embodiments 1-7, wherein the inner core comprises a plurality of ultrasound radiating members extending along a length of the ultrasound catheter.
Embodiment 9: The ultrasound catheter of Embodiment 8, wherein the flexible circuit comprises a plurality of joints between traces of dissimilar materials.
Embodiment 10: The ultrasound catheter of Embodiment 9, wherein the plurality of joints between traces of dissimilar materials extend along the length of the ultrasound catheter in which the plurality of ultrasound radiating members is positioned.
Embodiment 11: The ultrasound catheter of Embodiment 10, wherein the joints between traces of dissimilar materials are formed by a plurality traces of a first material connected to a single trace of second dissimilar material.
Embodiment 12: The ultrasound catheter of Embodiment 1, wherein the flexible circuit comprises a plurality of traces formed on the flexible circuit separated by insulating material, the plurality of traces comprising at least two traces of a first material connected to a single trace of second dissimilar material at different points along a length of the flexible circuit.
Embodiment 13: A method of manufacturing a catheter comprising:
Embodiment 14: The method of manufacturing of Embodiment 13, wherein the flexible circuit is configured to form a thermocouple.
Embodiment 15: The method of manufacturing of Embodiment 13, further comprising: forming an inner core, wherein the inner core is configured to be insertable into the inner tubular body.
Embodiment 16: The method of manufacturing of Embodiment 13, wherein inserting the elongate fluid delivery body and inserting the temperature sensor forms an asymmetrical cross-section in the catheter.
Embodiment 17: An ultrasound catheter comprising:
Embodiment 18: The ultrasound catheter of Embodiment 17, wherein the temperature sensor is formed by a flexible circuit.
Embodiment 19: An ultrasound catheter of Embodiment 18, wherein the temperature sensor is located in the widest portion of the asymmetrical gap.
Embodiment 20: A flexible circuit for a catheter, the flex circuit comprising a plurality of traces formed on the flexible circuit separated by insulating material, the plurality of traces comprising at least two traces of a first material connected to a single trace of second dissimilar material at different points along a length of the flexible circuit.
Embodiment 22: The flexible circuit of Embodiment 20, wherein the second dissimilar material is Constantan and the first material is copper.
Furthermore, the skilled artisan will recognize the interchangeability of various features from different embodiments disclosed herein. Similarly, the various features and steps discussed above, as well as other known equivalents for each such feature or step, can be mixed and matched by one of ordinary skill in this art to perform methods in accordance with principles described herein. Additionally, the methods which is described and illustrated herein is not limited to the exact sequence of acts described, nor is it necessarily limited to the practice of all of the acts set forth. Other sequences of events or acts, or less than all of the events, or simultaneous occurrence of the events, may be utilized in practicing the embodiments of the invention.
Although the invention has been disclosed in the context of certain embodiments and examples, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses and obvious modifications and equivalents thereof. Accordingly, the invention is not intended to be limited by the specific disclosures of embodiments herein.
This application is a continuation of U.S. application Ser. No. 15/178,398 filed Jun. 9, 2016, now U.S. Pat. No. 10,495,520; which claims the benefit of priority to U.S. Provisional Application No. 62/173,863, filed Jun. 10, 2015, the entirety of which are herein incorporated by reference.
| Number | Date | Country | |
|---|---|---|---|
| 62173863 | Jun 2015 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15178398 | Jun 2016 | US |
| Child | 16702520 | US |
