System for preventing or treating thrombosis associated with a vascular access device

Abstract

A system for preventing or treating thrombosis associated with a vascular access device (VAD) may include an ultrasound transducer configured to emit thrombus-disrupting ultrasound waves into a patient's body around the VAD. The ultrasound transducer may include a fixation means for fixing the ultrasound transducer to the patient on the VAD. A method of such a system may include an ultrasound-emitting step. The ultrasound-emitting step may include emitting the thrombus-disrupting ultrasound waves from the ultrasound transducer into the patient's body around the VAD.

Description

[Background technology]

[0001] Maintaining patency of a vascular access device (VAD), such as a central venous catheter, can be challenging due to a variety of patient-, VAD-, and treatment-related factors. Indeed, thrombi, including intraluminal clots, can easily form within the VAD, such as within the ends or tip of the VAD, or thrombi, including mural or occlusive thrombi, can easily form around the VAD, such as around the ends or tip of the VAD, or a combination of these, necessitating intervention. For this reason, blood thinners are often recommended during VAD use. Summary of the Invention [Problem to be solved by the invention]

[0002] However, blood thinners may be contraindicated in some patients, and blood thinners are generally prophylactic in that they do not disrupt thrombi that persist despite the presence of blood thinners. Clearly, maintaining VAD patency is important to minimize interruptions in therapeutic intervention, particularly those associated with replacing even partially occluded VADs, which increase the cost of care. Thus, there is a need for systems and methods for extending VAD life and enhancing therapeutic efficacy.

[0003] Disclosed herein are systems and methods for preventing or treating thrombosis associated with a VAD. [Means for solving the problem]

[0004] Disclosed herein is a system for preventing or treating thrombosis associated with a VAD. In some embodiments, the system includes an ultrasound transducer configured to emit thrombus-disrupting ultrasound waves into a patient's body surrounding the VAD. The ultrasound transducer includes a fixation means for fixating the ultrasound transducer on the VAD to the patient.

[0005] In some embodiments, the fastening means is an adhesive configured to adhere the ultrasound transducer to the patient's skin, thereby holding the ultrasound transducer in place on the VAD.

[0006] In some embodiments, the fixation means comprises a strap configured to be wrapped around the patient's torso, limb, or neck to hold the ultrasound transducer in position on the VAD.

[0007] In some embodiments, the fixation means comprises a clip configured to be clipped around the patient's torso, limb, or neck to hold the ultrasound transducer in position on the VAD.

[0008] In some embodiments, the system further includes a console operatively coupled to the ultrasound transducer, the console including one or more processors and a memory including instructions configured, when executed by the one or more processors, to instantiate one or more processes, the one or more processes configured to implement i) a pre-programmed ultrasound emission profile or ii) a custom ultrasound emission profile based on diagnostic data for the prevention or treatment of thrombosis associated with the VAD.

[0009] In some embodiments, the pre-programmed or custom ultrasound emission profile includes one or more periods of continuous ultrasound emissions, one or more periods of pulsed ultrasound emissions, a constant ultrasound power level, one or more different ultrasound power levels, a constant ultrasound frequency, one or more different ultrasound frequencies, or a combination thereof.

[0010] In some embodiments, the diagnostic data includes ultrasound imaging data. In some embodiments, the ultrasound transducer doubles as an ultrasound probe. In some embodiments, the system further includes a display screen, optionally integrated with the console, configured to display an ultrasound image, including at least a blood vessel, of a patient in which the VAD is to be placed.

[0011] In some embodiments, the VAD is a catheter. In some embodiments, the VAD is a port. In some embodiments, the VAD is an arteriovenous graft.

[0012] Also disclosed herein is a system method for preventing or treating thrombosis associated with a VAD. In some embodiments, the method includes an ultrasound emission step. The ultrasound emission step includes emitting thrombus-disrupting ultrasound waves from an ultrasound transducer into the patient's body around the VAD. The ultrasound transducer includes a fixation means for fixing the ultrasound transducer to the patient on the VAD.

[0013] In some embodiments, the fastening means is an adhesive that holds the ultrasound transducer in place on the VAD by adhering it to the patient's skin. In some embodiments, the fixation means comprises a strap that is wrapped around the patient's torso, limb, or neck to hold the ultrasound transducer in position on the VAD.

[0014] In some embodiments, the fixation means comprises a clip that clips around the patient's torso, limb, or neck to hold the ultrasound transducer in place on the VAD.

[0015] In some embodiments, the method further includes an instantiation step and an emission profile implementation step. The instantiation step includes instantiating one or more processes when instructions stored in a memory of the console are executed by one or more processors of the console. The console is operably coupled to the ultrasound transducer. The emission profile implementation step includes implementing, according to the one or more processes, i) a pre-programmed ultrasound emission profile or ii) a custom ultrasound emission profile based on diagnostic data for preventing or treating thrombosis associated with the VAD.

[0016] In some embodiments, the pre-programmed or custom ultrasound emission profile includes one or more periods of continuous ultrasound emissions, one or more periods of pulsed ultrasound emissions, a constant ultrasound power level, one or more different ultrasound power levels, a constant ultrasound frequency, one or more different ultrasound frequencies, or a combination thereof.

[0017] In some embodiments, the diagnostic data includes ultrasound imaging data. In some embodiments, the method further includes a scanning step, which includes transmitting emitted ultrasound signals into the patient's body around the VAD, receiving echoed ultrasound signals from the patient, and processing the echoed ultrasound signals into ultrasound imaging data. The ultrasound transducer doubles as an ultrasound probe.

[0018] In some embodiments, the method further includes a displaying step, which includes displaying an ultrasound image, optionally on a display screen integral with the console, the ultrasound image including at least a blood vessel of the patient in which the VAD is positioned.

[0019] In some embodiments, the VAD is a catheter. In some embodiments, the VAD is a port. In some embodiments, the VAD is an arteriovenous graft.

[0020] These and other features of the concepts provided herein will become more apparent to those skilled in the art upon consideration of the accompanying drawings and the following description, which describe in more detail certain embodiments of such concepts. [Brief explanation of the drawings]

[0021] [Figure 1] 1 illustrates a system for preventing or treating VAD-associated thrombosis, according to some embodiments. [Figure 2] 10 illustrates disruption of a mural thrombus using thrombus-disrupting ultrasound waves from an ultrasound transducer of the system, according to some embodiments. [Figure 3] 10 illustrates disruption of an intraluminal thrombus using thrombus-disrupting ultrasound waves from an ultrasound transducer of the system, according to some embodiments. [Figure 4] FIG. 1 illustrates a side view of an ultrasound transducer having a clip for clipping the ultrasound transducer to a patient, according to some embodiments. [Figure 5] 1 illustrates a side view of an ultrasound transducer having a strap for securing the ultrasound transducer to a patient, according to some embodiments. [Figure 6] 1 shows a block diagram of a system for preventing or treating VAD-associated thrombosis, according to some embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0022] Before disclosing some specific embodiments in more detail, it should be understood that the specific embodiments disclosed herein do not limit the scope of the concepts provided herein. It should also be understood that a specific embodiment disclosed herein may have features that are readily separable from the specific embodiment and that can be combined or substituted in any way with features of any of the other embodiments disclosed herein.

[0023] Regarding the terms used herein, it should also be understood that these terms are intended to describe certain specific embodiments and are not intended to limit the scope of the concepts provided herein. Ordinal numbers (e.g., first, second, third, etc.) are generally used to distinguish or identify different features or steps within a group of features or steps and do not provide sequential or numerical limitations. For example, "first," "second," and "third" features or steps do not necessarily have to appear in that order, and a particular embodiment including such features or steps is not necessarily limited to three features or steps. In addition, any of the aforementioned features or steps may similarly include one or more further features or steps unless otherwise indicated. Designations such as "left," "right," "top," "bottom," "front," and "back" are used for convenience and do not imply, for example, a specific fixed position, orientation, or direction. Instead, such designations are used to reflect, for example, a relative position, orientation, or direction. The singular forms "a," "an," and "the" include plural references unless the context clearly dictates otherwise.

[0024] With respect to "proximal," for example, a "proximal portion" or "proximal section" of a medical device, such as catheter 106, includes the portion or section of the medical device intended to be near the clinician when the medical device is used on a patient. Similarly, a "proximal length" of a medical device includes the length of the medical device intended to be near the clinician when the medical device is used on a patient. A "proximal end" of a medical device is the end of the medical device intended to be near the clinician when the medical device is used on a patient. The proximal portion, section, or length of a medical device may include the proximal end of the medical device, and in such cases, the proximal portion, section, or length of the medical device may be further designated as the "proximal end portion," "proximal end section," or "proximal end length" of the medical device. That is, the proximal portion, section, or length of a medical device need not include the proximal end of the medical device. Indeed, unless the context suggests otherwise, a proximal portion, section, or length of a medical device is not a terminal portion, section, or length of the medical device.

[0025] With respect to "distal," for example, a "distal portion" or "distal section" of a medical device, such as catheter 106, includes the portion or section of the medical device intended to be near or within a patient when the medical device is used with the patient. Similarly, for example, a "distal length" of a catheter includes the length of the catheter intended to be near or within a patient when the catheter is used with the patient. A "distal end" of a medical device is the end of the medical device intended to be near or within a patient when the medical device is used with the patient. A distal portion, section, or length of a medical device may include the distal end of the medical device, and in such cases, the distal portion, section, or length of the medical device may be further designated as a "distal end portion," "distal end section," or "distal end length" of the medical device. That is, a distal portion, section, or length of a medical device need not include the distal end of the medical device. Indeed, unless the context suggests otherwise, a distal portion, section, or length of a medical device is not the terminal portion, section, or length of the medical device.

[0026] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art. Maintaining the patency of a vascular access device (VAD), such as a central venous catheter, can be challenging due to a variety of factors related to the patient, the VAD, and the treatment. Indeed, thrombi, including intraluminal clots, can easily form within the VAD, such as within the end or tip of the VAD; thrombi, including mural or occlusive thrombi, can easily form around the VAD, such as around the end or tip of the VAD, or a combination of these, necessitating treatment. For this reason, blood thinners are often recommended during VAD use. However, blood thinners may be contraindicated in some patients, and blood thinners are generally prophylactic in that they do not disrupt stubbornly forming clots despite the presence of blood thinners. Clearly, maintaining VAD patency is important to minimize interruptions in treatment, particularly those associated with replacing a partially occluded VAD, which increases the cost of care. Therefore, there is a need for systems and methods for extending VAD life and improving treatment outcomes.

[0027] system FIG. 1 illustrates a system 100 for preventing or treating VAD-associated thrombosis, according to some embodiments.

[0028] As shown, the system 100 may include an ultrasound transducer 102 configured to emit thrombus-disrupting ultrasound waves into the patient's body around a VAD 104, such as a catheter 106.

[0029] Figure 2 illustrates disruption of a mural thrombus 108 using thrombus-disrupting ultrasound from the ultrasound transducer 102 of the system 100, according to some embodiments. Figure 3 illustrates disruption of an intraluminal thrombus 110 using thrombus-disrupting ultrasound from the ultrasound transducer 102 of the system 100, according to some embodiments.

[0030] As shown, when the ultrasound transducer 102 is secured to a patient, for example, on a VAD 104, the ultrasound transducer 102 can emit thrombus-fragmenting ultrasound waves into the patient's body around the VAD 104 to prevent thrombus formation or to fragment existing thrombi through fibrinolysis. Indeed, the latter is shown in Figure 2 as ultrasound-induced fibrinolysis of a mural thrombus 108 occluding the tip 107 of the catheter 106. The latter is alternatively shown in Figure 3 as ultrasound-induced fibrinolysis of an intraluminal thrombus 110 occluding the tip 107 of the catheter 106.

[0031] 1-3 , it should be understood that system 100 is not limited to preventing or treating VAD-associated thrombosis within a catheter. Indeed, VAD 104 may alternatively be a port, an arteriovenous graft, or some other VAD. If VAD 104 is a port, prevention or treatment of VAD-associated thrombosis typically occurs within the stem of the port. Also, if VAD 104 is an arteriovenous graft, prevention or treatment of VAD-associated thrombosis may occur anywhere along the length of the arteriovenous graft, especially in any length of an arteriovenous graft having a relatively narrow radius.

[0032] Figure 4 shows a side view of an ultrasound transducer 102 having a clip 112 for clipping the ultrasound transducer 102 to a patient, according to some embodiments. Figure 5 shows a side view of an ultrasound transducer 102 having a strap 114 for securing the ultrasound transducer 102 to a patient, according to some embodiments.

[0033] As shown, the ultrasound transducer 102 may include a securing means for securing the ultrasound transducer 102 to the patient on the VAD 104. Such securing means may include, but are not limited to, an adhesive, the clip 112 of FIG. 4 , the strap 114 of FIG. 5 , or the like. In one example, the securing means may be the adhesive described above, which may be configured to adhere the head 142 of the ultrasound transducer 102 to the patient's skin to hold the ultrasound transducer 102 in position on the VAD 104. In another example, the securing means may be the clip 112 of FIG. 4 , which may be configured to clip around the patient's torso, limb, or neck to hold the ultrasound transducer 102 in position on the VAD 104. In yet another example, the securing means may be the strap 114 of FIG. 5 , which may be configured to be wrapped around the patient's torso, limb, or neck to hold the ultrasound transducer 102 in position on the VAD 104. Such a strap 114 may be fastened around the patient to hold the ultrasound transducer 102 in position on the VAD 104. Alternatively, the strap 114 may include a buckle 116 for fastening the strap 114 around the patient to hold the ultrasound transducer 102 in position on the VAD 104.

[0034] FIG. 6 shows a block diagram of a system 100 for preventing or treating VAD-associated thrombosis, according to some embodiments. As shown, the system 100 may further include a console 118 operably coupled to the ultrasound transducer 102 .

[0035] The console 118 may include one or more processors 120 and a memory 122 having stored thereon instructions 124 configured to instantiate one or more processes when executed by the one or more processors 120 to control various functions of the system 100. In one example, the one or more processes may include scanning with the ultrasound transducer 102 when the ultrasound transducer 102 is configured to double as an ultrasound probe. Such scanning may include transmitting emitted ultrasound signals into the patient's body around the VAD 104, receiving reflected ultrasound signals from the patient, and processing the reflected ultrasound signals into ultrasound imaging data. In another example, the one or more processes may include automatically identifying any thrombus occluding the VAD 104 using logic 126, such as thrombus identification logic. In another example, the one or more processes may include disrupting any thrombus within the VAD 104 according to an ultrasound emission profile 128, such as a preprogrammed or custom ultrasound emission profile, based on any diagnostic data, including, but not limited to, ultrasound imaging data. In particular, the ultrasound emission profile 128 may include one or more periods of continuous ultrasound emission, one or more periods of pulsed ultrasound emission, a constant ultrasound power level, one or more different ultrasound power levels, a constant ultrasound frequency, one or more different ultrasound frequencies, or combinations thereof, as needed to disrupt any thrombus within the VAD 104. (See the example ultrasound emission profile 128 in FIG. 1 , which includes a short period of ultrasound emission comprising three different pulses over a time t, each pulse at a different power level P and at either frequency fa or fb, where fa > fb.)

[0036] The console 118 may further include a display screen 130 integrated therewith. Alternatively, the display screen 130 may be separate from and communicatively coupled to the console 118. The display screen 130 may be configured to provide a graphical user interface ("GUI") and to display information thereon, such as an ultrasound image including at least the blood vessels of the patient in which the VAD 104 is placed, optionally along with any thrombus. Additionally, such information may include an ultrasound emission profile 128 as shown in FIG. 1.

[0037] The console 118 may further include a console button interface 131 with one or more buttons configured to immediately invoke one or more desired system modes on the display screen 130, such as a scan mode for collecting ultrasound imaging data to display an ultrasound image on the display screen 130, an identification mode for automatically identifying any thrombus within the VAD 104 from the ultrasound image, or a fragmentation mode for fragmenting any thrombus within the VAD 104 according to an ultrasound emission profile 128 (e.g., a pre-programmed or custom ultrasound emission profile).

[0038] The console 118 may further include a digital controller / analog interface 132 configured to communicate with one or more processors 120, other components of the console 118, and other components of the system 100, such as the ultrasound transducer 102, and to manage the interfaces between the aforementioned components.

[0039] The console 118 may further include a power connection 134 configured to allow operable connection to an external power source 136. Additionally or alternatively, the console 118 may include an internal power source 138 (e.g., a battery). Whether or not the console 118 includes an internal power source 138, the console 118 includes a power management circuit 140 with a digital controller / analog interface 132 for regulating and distributing power.

[0040] When the ultrasound transducer 102 is configured to double as an ultrasound probe, the system 100 is configured to scan for thrombus within the VAD 104 and, optionally, to automatically identify the thrombus using thrombus identification logic. Advantageously, such a system 100 may be useful for verifying the patency of the VAD 104 after disrupting the thrombus within the VAD 104.

[0041] Whether or not the ultrasound transducer 102 is configured to double as an ultrasound probe, the ultrasound transducer 102 includes a head 142 housing an array of ultrasound transducers 144, which may include piezoelectric transducers or capacitive micromachined ultrasound transducers (CMUTs). As described above, the head 142 of the ultrasound transducer 102 is configured to be placed in contact with the patient's skin and held in position on the VAD 104 by a fixation means of the ultrasound transducer 102. In this manner, the system 100 can emit thrombus-disrupting ultrasound waves via the ultrasound transducer 102 into the patient's body around the VAD 104 to prevent thrombus formation or disrupt existing thrombi through fibrinolysis. Additionally, if the ultrasound transducer 102 doubles as an ultrasound probe, the system 100 can further scan for thrombi within the VAD 104 and, optionally, automatically identify thrombi using logic 126, such as thrombus identification logic, as described above. In particular, once any thrombi are identified, the system 100 can automatically activate the array of ultrasound transducers 144 to disrupt one or more thrombi by fibrinolysis.

[0042] The ultrasound transducer 102 may further include a button and memory controller 146 for managing button operations and for managing the operation of the ultrasound transducer 102 itself, particularly when the ultrasound transducer 102 doubles as an ultrasound probe operatively connected to the console 118. If present, the button and memory controller 146 is in operative communication with a probe interface 148 of the console 118. The probe interface 148 includes an input / output ("I / O") component 150 for interfacing with the array of ultrasound transducers 144 and a button and memory I / O component 152 for interfacing with the button and memory controller 146.

[0043] Additionally or alternatively, the system 100 may be configured to maintain or even promote vascular health, such as to maintain adequate blood flow, reduce vascular irritation, etc. For example, if a vessel in which a VAD, such as a PICC, is placed is no longer viable (not necessarily due to thrombosis) and needs to be removed, the system may optionally be used to maintain and promote vascular health of the remaining vessel for replacement of the PICC at a later date.

[0044] method Methods include those of system 100, including methods for preventing or treating thrombosis associated with a VAD. Such methods may include one or more steps selected from an instantiation step, a scanning step, a display step, or an identification step in the case where the ultrasound transducer 102 doubles as an ultrasound probe, an emission profile execution step, and an ultrasound emission step.

[0045] The instantiating step may include instantiating one or more of the processes described above upon execution of instructions 124 stored in memory 122 of console 118 by one or more processors 120 of console 118.

[0046] The scanning step may include sending emitted ultrasound signals into the patient's body around the VAD 104, receiving echoed ultrasound signals from the patient, and processing the echoed ultrasound signals into ultrasound imaging data.

[0047] The displaying step may include displaying the ultrasound image on a display screen 130, optionally integrated with the console 118. The ultrasound image may include at least the patient's blood vessel in which the VAD 104 is positioned.

[0048] The identifying step may include automatically identifying any thrombus within the VAD 104 using logic 126, such as thrombus identification logic. The ultrasound emission step may include emitting thrombus-disrupting ultrasound from the ultrasound transducer 102 into the patient's body around the VAD 104 .

[0049] The emission profile implementing step may include implementing an ultrasound emission profile 128 for preventing or treating thrombosis associated with the VAD. Again, the ultrasound emission profile 128 may include a preprogrammed ultrasound emission profile or a custom ultrasound emission profile based on diagnostic data, such as ultrasound imaging data. As described above, the ultrasound emission profile 128 may include one or more periods of continuous ultrasound emission, one or more periods of pulsed ultrasound emission, a constant ultrasound power level, one or more different ultrasound power levels, a constant ultrasound frequency, one or more different ultrasound frequencies, or a combination thereof.

[0050] Although some specific embodiments are disclosed herein, and the specific embodiments are disclosed in some detail, the specific embodiments are not intended to limit the scope of the concepts provided herein. Additional adaptations and / or modifications may be apparent to those skilled in the art, and the broader aspects also encompass these adaptations and / or modifications. Thus, one can deviate from the specific embodiments disclosed herein without departing from the scope of the concepts provided herein.

Claims

1. 1. A system for preventing or treating thrombosis associated with a vascular access device (VAD), comprising: A system comprising an ultrasound transducer configured to emit thrombus-disrupting ultrasound into a patient's body around a thrombus associated with a VAD, or a thrombus formed within, around, or both within and around the VAD, the ultrasound transducer including a fixation means for fixing the ultrasound transducer to the patient on the VAD.

2. The system of claim 1 , wherein the fastening means is an adhesive configured to adhere the ultrasound transducer to the patient's skin, thereby holding the ultrasound transducer in place on the VAD.

3. The system of claim 1 , wherein the fixation means comprises a strap configured to be wrapped around the patient's torso, limb, or neck to hold the ultrasound transducer in position on the VAD.

4. 2. The system of claim 1, wherein the fixation means comprises a clip configured to clip around the patient's torso, limb, or neck to hold the ultrasound transducer in position on the VAD.

5. The system according to any one of claims 1 to 4, a console operably coupled to the ultrasonic transducer, the console comprising: one or more processors; and a memory containing instructions configured, when executed by the one or more processors, to instantiate one or more processes, the one or more processes being configured to implement i) a pre-programmed ultrasound emission profile or ii) a custom ultrasound emission profile based on diagnostic data for the prevention or treatment of thrombosis associated with a VAD.

6. 6. The system of claim 5, wherein the pre-programmed or custom ultrasound emission profile comprises one or more periods of continuous ultrasound emissions, one or more periods of pulsed ultrasound emissions, a constant ultrasound power level, one or more different ultrasound power levels, a constant ultrasound frequency, one or more different ultrasound frequencies, or a combination thereof.

7. The system of claim 5 or 6, wherein the diagnostic data includes ultrasound imaging data.

8. The system of claim 7 , wherein the ultrasonic transducer doubles as an ultrasonic probe.

9. The system of claim 7 or 8, further comprising a display screen optionally integrated with the console, the display screen configured to display an ultrasound image including at least a blood vessel of the patient in which the VAD is placed.

10. The system of any one of claims 1 to 9, wherein the VAD is a catheter.

11. The system of any one of claims 1 to 9, wherein the VAD is a port.

12. The system of any one of claims 1 to 9, wherein the VAD is an arteriovenous graft.

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