Patent Description:
The present technology relates generally to devices and methods for removing obstructions from body lumens. Some embodiments of the present technology relate to devices and methods for electrically enhanced removal of clot material from blood vessels.

Many medical procedures use medical device(s) to remove an obstruction (such as clot material) from a body lumen, vessel, or other organ. An inherent risk in such procedures is that mobilizing or otherwise disturbing the obstruction can potentially create further harm if the obstruction or a fragment thereof dislodges from the retrieval device. If all or a portion of the obstruction breaks free from the device and flows downstream, it is highly likely that the free material will become trapped in smaller and more tortuous anatomy. In many cases, the physician will no longer be able to use the same retrieval device to again remove the obstruction because the device may be too large and/or immobile to move the device to the site of the new obstruction.

Procedures for treating ischemic stroke by restoring flow within the cerebral vasculature are subject to the above concerns. The brain relies on its arteries and veins to supply oxygenated blood from the heart and lungs and to remove carbon dioxide and cellular waste from brain tissue. Blockages that interfere with this blood supply eventually cause the brain tissue to stop functioning. If the disruption in blood occurs for a sufficient amount of time, the continued lack of nutrients and oxygen causes irreversible cell death. Accordingly, it is desirable to provide immediate medical treatment of an ischemic stroke.

To access the cerebral vasculature, a physician typically advances a catheter from a remote part of the body (typically a leg) through the abdominal vasculature and into the cerebral region of the vasculature. Once within the cerebral vasculature, the physician deploys a device for retrieval of the obstruction causing the blockage. Concerns about dislodged obstructions or the migration of dislodged fragments increases the duration of the procedure at a time when restoration of blood flow is paramount. Furthermore, a physician might be unaware of one or more fragments that dislodge from the initial obstruction and cause blockage of smaller more distal vessels.

Many physicians currently perform thrombectomies (i.e. clot removal) with stents to resolve ischemic stroke. Typically, the physician deploys a stent into the clot in an attempt to push the clot to the side of the vessel and re-establish blood flow. Tissue plasminogen activator ("tPA") is often injected into the bloodstream through an intravenous line to break down a clot. However, it takes time for the tPA to reach the clot because the tPA must travel through the vasculature and only begins to break up the clot once it reaches the clot material. tPA is also often administered to supplement the effectiveness of the stent. Yet, if attempts at clot dissolution are ineffective or incomplete, the physician can attempt to remove the stent while it is expanded against or enmeshed within the clot. In doing so, the physician must effectively drag the clot through the vasculature, in a proximal direction, into a guide catheter located within vessels in the patient's neck (typically the carotid artery). While this procedure has been shown to be effective in the clinic and easy for the physician to perform, there remain some distinct disadvantages to using this approach.

For example, one disadvantage is that the stent may not sufficiently retain the clot as it pulls the clot to the catheter. In such a case, some or all of the clot might remain in the vasculature. Another risk is that, as the stent mobilizes the clot from the original blockage site, the clot might not adhere to the stent as the stent is withdrawn toward the catheter. This is a particular risk when passing through bifurcations and tortuous anatomy. Furthermore, blood flow can carry the clot (or fragments of the clot) into a branching vessel at a bifurcation. If the clot is successfully brought to the end of the guide catheter in the carotid artery, yet another risk is that the clot may be "stripped" or "sheared" from the stent as the stent enters the guide catheter.

<CIT> relates to a system for delivering energy-based treatment for in-stent restenosis and other stenosis of the vasculature. This system comprises an elongate flexible catheter body,a radially expandable structure near the distal end of the catheter body, a plurality of electrodes positioned on the radially expandable structure so as to engage tissue upon expansion of the radially expandable structure, a power source coupled with the electrodes, and a processor coupled with the power source.

In view of the above, there remains a need for improved devices and methods that can remove occlusions from body lumens and/or vessels.

According to the invention, there is provided a thrombectomy device according to any one of claims <NUM> to <NUM>. No methods of treatment or surgery are claimed.

Mechanical thrombectomy (i.e., clot-grabbing and removal) has been effectively used for treatment of ischemic stroke. Although most clots can be retrieved in a single pass attempt, there are instances in which multiple attempts are needed to fully retrieve the clot and restore blood flow through the vessel. Additionally, there exist complications due to detachment of the clot from the interventional element during the retrieval process as the interventional element and clot traverse through tortuous intracranial vascular anatomy. For example, the detached clot or clot fragments can obstruct other arteries leading to secondary strokes. The failure modes that contribute to clot release during retrieval are: (a) boundary conditions at bifurcations; (b) changes in vessel diameter; and (c) vessel tortuosity, amongst others.

Certain blood components, such as platelets and coagulation proteins, display negative electrical charges. The treatment systems of the present technology provide an interventional element carrying one or more electrodes and a current generator configured to positively charge the interventional element during one or more stages of a thrombectomy procedure. For example, the current generator may apply a constant or pulsatile direct current (DC) to the electrodes. The positively charged electrodes and/or interventional element attract negatively charged blood components, thereby improving attachment of the thrombus to the interventional element and reducing the number of device passes or attempts necessary to fully retrieve the clot.

One approach to delivering current to an interventional element is to conduct current along a core wire coupled to a proximal end of the interventional element. However, the inventors have discovered that this approach can lead to disadvantageous concentration of electrical charge along a proximal portion of the interventional element, with insufficient charge density in more distal portions of the interventional element (e.g., along some or all of the working length of the interventional element). This is particularly true of interventional elements having a proximal portion that tapers to a connection point with the core wire. This concentration of current in the proximal portion can reduce the efficacy of electrostatic enhancement of clot adhesion, as the mechanical clot engagement occurs primarily at a location distal to the region at which the charge density is greatest. Additionally, delivery of current in this manner may require a hypotube or other additional structural element to be coupled to the core wire, thereby stiffening the core assembly and rendering navigability of torturous vasculature more difficult.

To overcome these and other problems, in some aspects of the present technology a treatment system includes one or more electrodes carried by or otherwise coupled to the interventional element. The electrodes can take the form of radiopaque markers affixed to a portion of the interventional element, and can be arranged so as to improve charge distribution over the surface of the interventional element during treatment. For example, by delivering current to electrodes affixed to the interventional element, electrical charge can be concentrated in select regions of the interventional element (e.g., regions adjacent to the delivery electrodes).

Current can flow to the delivery electrodes over a plurality of electrical leads extending between the current generator (which may be positioned extracorporeally) and the electrodes. One or more return electrodes can likewise be coupled to the interventional element, and optionally may also double as radiopaque marker(s). Additionally or alternatively, the return electrode(s) may be positioned elsewhere (e.g., a needle, a grounding pad, a conductive element carried by a one or more catheters of the treatment system, a guide wire, and/or any other suitable conductive element configured to complete an electrical circuit with the delivery electrodes and an extracorporeally positioned current generator). When the interventional element is placed in the presence of blood (or any other electrolytic medium) and voltage is applied at the terminals of the current generator, current flows along the leads to the delivery electrodes and to the interventional element, through the blood, and to the return electrode(s), thereby positively charging at least a portion of the interventional element and adhering clot material thereto.

The treatment systems of the present technology can further improve adhesion of the clot to the interventional element by positioning the delivery electrodes with respect to the interventional element in a manner that improves charge distribution, and/or by modifying characteristics of the interventional element. For example, in some embodiments, some or all of the interventional element can be coated with one or more highly conductive materials, such as gold, to improve clot adhesion. In some aspects of the present technology, a working length of the interventional element may be coated with the conductive material while a non-working length of the interventional element may be coated with an insulative material. Additional features and advantages of the present technology are described below, and in part will be apparent from the description, or may be learned by practice of the present technology. The advantages of the present technology will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

In this specification the non-SI unit 'inch' or (") is used, which may be converted to the SI or metric unit according to the following conversion: <NUM> inch ≊ <NUM>.

Many aspects of the present technology can be better understood with reference to the following drawings. The components in the drawings are not necessarily to scale. Instead, emphasis is placed on illustrating clearly the principles of the present disclosure.

The present technology provides devices, systems, and methods for removing clot material from a blood vessel lumen. Although many of the embodiments are described below with respect to devices, systems, and methods for treating a cerebral or intracranial embolism, other applications and other embodiments in addition to those described herein are within the scope of the technology. For example, the treatment systems and methods of the present technology may be used to remove emboli from body lumens other than blood vessels (e.g., the digestive tract, etc.) and/or may be used to remove emboli from blood vessels outside of the brain (e.g., pulmonary, abdominal, cervical, or thoracic blood vessels, or peripheral blood vessels including those within the legs or arms, etc.). In addition, the treatment systems and methods of the present technology may be used to remove luminal obstructions other than clot material (e.g., plaque, resected tissue, foreign material, etc.).

<FIG> illustrates a view of an electrically enhanced treatment system <NUM> according to one or more embodiments of the present technology. As shown in <FIG>, the treatment system <NUM> can include a current generator <NUM> and a treatment device <NUM> having a proximal portion 40a configured to be coupled to the current generator <NUM> and a distal portion 40b configured to be intravascularly positioned within a blood vessel (such as an intracranial blood vessel) at a treatment site at or proximate a thrombus. The treatment device <NUM> includes an interventional element <NUM> at the distal portion 10b, a handle <NUM> at the proximal portion 10a, and a plurality of elongated shafts or members extending therebetween. For example, in some embodiments, such as that shown in <FIG>, the treatment device <NUM> includes a first catheter <NUM> (such as a balloon guide catheter), a second catheter <NUM> (such as a distal access catheter or aspiration catheter) configured to be slidably disposed within a lumen of the first catheter <NUM>, a third catheter <NUM> (such as a microcatheter) configured to be slidably disposed within a lumen of the second catheter <NUM>, and a core member <NUM> configured to be slidably disposed within a lumen of the third catheter <NUM>. In some embodiments, the treatment device <NUM> does not include the second catheter <NUM>. The first catheter <NUM> can be coupled to the handle <NUM>, which provides proximal access to the core member <NUM> that engages the interventional element <NUM> at a distal end thereof. The current generator <NUM> may be coupled to a proximal portion of one or more leads (not shown) to deliver electrical current to the interventional element <NUM> and thereby provide an electrically charged environment at the distal portion 40b of the treatment device <NUM>, as described in more detail below.

In some embodiments, the treatment system <NUM> includes a suction source <NUM> (e.g., a syringe, a pump, etc.) configured to be fluidically coupled (e.g., via a connector <NUM>) to a proximal portion of one or more of the first catheter <NUM>, the second catheter <NUM>, and/or the third catheter <NUM> to apply negative pressure therethrough. In some embodiments, the treatment system <NUM> includes a fluid source <NUM> (e.g., a fluid reservoir, a syringe, pump, etc.) configured to be fluidically coupled (e.g., via the connector <NUM>) to a proximal portion of one or more of the first catheter <NUM>, the second catheter <NUM>, and/or the third catheter <NUM> to supply fluid (e.g., saline, contrast agents, a drug such as a thrombolytic agent, etc.) to the treatment site.

According to some embodiments, the catheters <NUM>, <NUM>, and <NUM> can each be formed as a generally tubular member extending along and about a central axis. According to some embodiments, the third catheter <NUM> is generally constructed to track over a conventional guidewire in the cervical anatomy and into the cerebral vessels associated with the brain and may also be chosen according to several standard designs that are generally available. Accordingly, the third catheter <NUM> can have a length that is at least <NUM> long, and more particularly may be between about <NUM> and about <NUM> long. Other designs and dimensions are contemplated.

The second catheter <NUM> can be sized and configured to slidably receive the third catheter <NUM> therethrough. As noted above, the second catheter <NUM> can be coupled at a proximal portion to a suction source <NUM> (<FIG>) such as a pump or syringe in order to supply negative pressure to a treatment site. The first catheter <NUM> can be sized and configured to slidably receive both the second catheter <NUM> and the third catheter <NUM> therethrough. In some embodiments, the first catheter <NUM> is a balloonguide catheter having an inflatable balloon or other expandable member surrounding the catheter shaft at or near its distal end. As described in more detail below with respect to <FIG>, in operation the first catheter <NUM> can first be advanced through a vessel and then its balloon can be expanded to anchor the first catheter <NUM> in place and/or arrest blood flow from areas proximal of the balloon, e.g. to enhance the effectiveness of aspiration performed via the first catheter <NUM> and/or other catheter(s). Next, the second catheter <NUM> can be advanced through the first catheter <NUM> until its distal end extends distally beyond the distal end of the first catheter <NUM>. The second catheter <NUM> can be positioned such that its distal end is adjacent a treatment site (e.g., a site of a blood clot within the vessel). The third catheter <NUM> may then be advanced through the second catheter <NUM> until its distal end extends distally beyond the distal end of the second catheter <NUM>. The interventional element <NUM> may then be advanced through the third catheter <NUM> for delivery to the treatment site.

According to some embodiments, the bodies of the catheters <NUM>, <NUM>, and <NUM> can be made from various thermoplastics, e.g., polytetrafluoroethylene (PTFE or TEFLON®), fluorinated ethylene propylene (FEP), high-density polyethylene (HDPE), polyether ether ketone (PEEK), etc., which can optionally be lined on the inner surface of the catheters or an adjacent surface with a hydrophilic material such as polyvinylpyrrolidone (PVP) or some other plastic coating. Additionally, either surface can be coated with various combinations of different materials, depending upon the desired results.

According to some embodiments, the current generator <NUM> can include an electrical generator configured to output medically useful electric current. <FIG> are schematic views of different embodiments of the current generator <NUM>. With reference to <FIG>, the current generator <NUM> can include a power source <NUM>, a first terminal <NUM>, a second terminal <NUM>, and a controller <NUM>. The controller <NUM> includes a processor <NUM> coupled to a memory <NUM> that stores instructions (e.g., in the form of software, code or program instructions executable by the processor or controller) for causing the power source <NUM> to deliver electric current according to certain parameters provided by the software, code, etc. The power source <NUM> of the current generator <NUM> may include a direct current power supply, an alternating current power supply, and/or a power supply switchable between a direct current and an alternating current. The current generator <NUM> can include a suitable controller that can be used to control various parameters of the energy output by the power source or generator, such as intensity, amplitude, duration, frequency, duty cycle, and polarity. For example, the current generator <NUM> can provide a voltage of about <NUM> volts to about <NUM> volts and a current of about <NUM> mA to about <NUM> mA.

<FIG> illustrates another embodiment of the current generator <NUM>, in which the controller <NUM> of <FIG> is replaced with drive circuitry <NUM>. In this embodiment, the current generator <NUM> can include hardwired circuit elements to provide the desired waveform delivery rather than a software-based generator of <FIG>. The drive circuitry <NUM> can include, for example, analog circuit elements (e.g., resistors, diodes, switches, etc.) that are configured to cause the power source <NUM> to deliver electric current via the first and second terminals <NUM>, <NUM> according to the desired parameters. For example, the drive circuitry <NUM> can be configured to cause the power source <NUM> to deliver periodic waveforms via the first and second terminals <NUM>, <NUM>. Particular parameters of the energy provided by the current generator <NUM> are described in more detail below with respect to <FIG>.

In some embodiments, one or more electrodes can be carried by, coupled to or mounted on the interventional element <NUM> (or the electrodes can comprise conductive elements or surfaces other than radiopaque elements/markers (if any)). The electrodes can optionally take the form of radiopaque elements or markers affixed to a portion of the interventional element <NUM>, and can be arranged so as to provide and/or improve electrical charge distribution over the surface of the interventional element <NUM> during treatment. Current can be delivered to the electrodes over a plurality of corresponding electrical leads extending between the current generator <NUM> and the electrodes affixed to the interventional element <NUM>. The electrodes can comprise delivery electrodes as well as one or more return electrodes, which can likewise be coupled to or formed on the interventional element <NUM>, or may be positioned elsewhere (e.g., as an external electrode <NUM>, or otherwise, as will be explained in greater detail below). When the interventional element <NUM> is placed in the presence of blood (or thrombus, and/or any other electrolytic medium which may be present, such as saline) and voltage is applied at the terminals of the current generator <NUM>, current flows from the generator along the leads to the delivery electrodes (and, optionally, to the interventional element <NUM> itself), through the blood (and/or other medium), and to the return electrode(s), thereby positively charging at least a portion of the interventional element <NUM> and promoting clot adhesion.

<FIG> is a side schematic view of the distal portion 40b of the treatment device <NUM> shown in <FIG>. As illustrated, the interventional element <NUM> can include a plurality of electrodes <NUM> disposed thereon. The electrodes <NUM> can take the form of electrically conductive members or surfaces coupled to or incorporated in the body of the interventional element <NUM> at various locations. For example, each electrode <NUM> can be coupled to a strut, to a projection extending away from a strut, to a distally extending tip, or any other suitable portion of the interventional element <NUM>. In some embodiments, the electrodes <NUM> can be radiopaque so as to be visible under fluoroscopy. (Generally, "radiopaque" as used herein refers to an element or component which is more visible under fluoroscopy than an adjacent portion of the interventional element <NUM> itself. ) In such configurations, the electrodes <NUM> can function as both radiopaque markers and electrodes. According to some embodiments, some or all of the electrodes <NUM> can take the form of coils, tubes, bands, plates, traces, or any other suitable structure that is electrically conductive, or both electrically conductive and radiopaque. Exemplary materials for the electrodes include copper, stainless steel, nitinol, platinum, gold, iridium, tantalum, alloys thereof, or any other suitable materials that are electrically conductive, or both electrically conductive and radiopaque. In some embodiments, the electrodes <NUM> are not radiopaque, and separate radiopaque markers may or may not be used in conjunction with such non-radiopaque electrodes <NUM>.

The electrodes <NUM> can each be coupled to a respective electrical lead <NUM> that may extend alongside the core member <NUM>, and/or be coupled to, wound around or incorporated into the core member <NUM>. When the thrombectomy device is in use with the catheter <NUM>, therefore, the lead(s) may extend through the lumen of the catheter <NUM>. The electrical leads <NUM> can be bundled together or otherwise grouped together in a lead bundle assembly <NUM> that extends proximally adjacent the core member <NUM> through the catheter <NUM>. The bundle assembly <NUM> can couple at a proximal end portion to the current generator (e.g., current generator <NUM>; <FIG>), with each individual lead <NUM> being electrically coupled to the current generator to carry current to a respective electrode <NUM>. Although <FIG> illustrates a separate electrical lead <NUM> coupled to each individual electrode <NUM>, in some embodiments any subset of electrodes <NUM> may share electrical connection via one or more leads <NUM>. For example, a lead may extend between two electrodes <NUM>, thereby placing those two electrodes in electrical communication with one another as well as the generator or other current source, when coupled thereto.

In some embodiments, a first subset of the electrodes <NUM> can be electrically coupled to the positive terminal of the current generator <NUM> via their respective leads <NUM>, and accordingly serve as delivery electrodes. Meanwhile, a second subset of the electrodes <NUM> can be electrically coupled to the negative terminal of the current generator <NUM> via their respective leads <NUM> and accordingly serve as return electrodes. In some embodiments, some or all of the delivery electrodes <NUM> can be in electrical communication with the body of the interventional element <NUM> (or electrically insulated therefrom), which may itself be electrically conductive. When some or all of the delivery electrodes <NUM> are in electrical communication with the (electrically conductive) body of the interventional element <NUM>, the positive/delivery lead <NUM> (e.g., a single such lead) can be electrically coupled to the body of the interventional element <NUM>, e.g., at or near the proximal end thereof, and thereby in electrical communication with some or all of the delivery electrodes <NUM>. As such, current carried by the delivery electrodes <NUM> can flow into the interventional element <NUM>, thereby generating a positive charge along at least a portion of the interventional element <NUM> (as well as any delivery electrodes <NUM> coupled to the body of the interventional element; in some embodiments, separate delivery electrodes <NUM> can be omitted and the body of the interventional element (or exposed portion(s) thereof) can serve as the delivery electrode(s)). In some embodiments, one or more regions of the interventional element <NUM> can be coated with an insulative material such that current carried from the delivery electrodes <NUM> to the interventional element <NUM> will not be carried by the surface of the interventional element <NUM> in the coated regions. As a result, the distribution of charge over the surface or along the length of the interventional element <NUM> can be located in the region(s) of the interventional element <NUM> that are not coated with an insulative material.

In some embodiments, the return electrodes <NUM> can be carried by the interventional element <NUM> but be electrically insulated from the body of the interventional element <NUM>. For example, the return electrodes <NUM> can be mounted over a portion of the interventional element <NUM> with an electrically insulating material disposed therebetween such that current carried by a return electrode <NUM> does not pass to the body of the interventional element <NUM>, but instead passes through the corresponding lead <NUM> coupled to the return electrode <NUM>. In some embodiments, the return electrodes <NUM> can be in electrical communication with at least a portion of the interventional element <NUM>.

During operation, the treatment system <NUM> can provide an electrical circuit in which current flows from the positive terminal of the current generator <NUM>, distally through the delivery leads <NUM> to delivery electrodes <NUM> and (optionally) to the interventional element <NUM>. Current then passes from the surface of the interventional element <NUM> (when suitably configured) and to the surrounding media (e.g., blood, tissue, thrombus, etc.) before returning via the return electrodes <NUM> carried by the interventional element <NUM>, proximally through the return leads <NUM>, and to the negative terminal of the current generator.

Instead of or in addition to the return electrodes <NUM> carried by the interventional element <NUM>, the return electrode(s) can assume a variety of different configurations. For example, in some embodiments, the return electrode is an external electrode <NUM> (<FIG>), such as a needle or grounding pad that is applied to a patient's skin. The needle or grounding pad can be coupled via one or more leads to the current generator <NUM> to complete the electrical circuit. In some embodiments, the return electrode is carried by a surrounding catheter (e.g., third catheter <NUM>, second catheter <NUM>, and/or first catheter <NUM>). In some embodiments, the return electrode can be an insulated guide wire having an exposed, electrically conductive portion at its distal end, or an exposed, electrically conductive portion of the core member <NUM> near its distal end.

Referring still to <FIG>, in some embodiments the interventional element <NUM> can be a metallic or electrically conductive thrombectomy device. For example, the interventional element <NUM> can include or be made of stainless steel, nitinol, cobalt-chromium, platinum, tantalum, alloys thereof, or any other suitable material. The interventional element <NUM> can have a low-profile, constrained or compressed configuration (not shown) for intravascular delivery to the treatment site within the third catheter <NUM>, and an expanded configuration for securing and/or engaging clot material and/or for restoring blood flow at the treatment site.

In some embodiments, the interventional element <NUM> is a mesh structure (e.g., a braid, a stent, etc.) formed of a superelastic material (e.g., Nitinol) or other resilient or self-expanding material configured to self-expand when released from the third catheter <NUM>. The interventional element <NUM> has a proximal portion 100a that may be coupled to the core member <NUM> and a distal portion 100b. The interventional element <NUM> further includes an open cell framework or body <NUM> and a coupling region <NUM> extending proximally from the body <NUM>. In some embodiments, the body <NUM> of the interventional element <NUM> can be generally tubular (e.g., cylindrical), and the proximal portion 100a of the interventional element <NUM> can be tapered proximally within the coupling region <NUM>.

In various embodiments, the interventional element <NUM> can take any number of forms, for example a removal device, a thrombectomy device, or other suitable medical device. For example, in some embodiments the interventional element <NUM> may be a stent and/or stent retriever, such as Medtronic's Solitaire™ Revascularization Device, Stryker Neurovascular's Trevo® ProVue™ Stentriever, or other suitable devices. In some embodiments, the interventional element <NUM> may be a coiled wire, a weave, and/or a braid formed of a plurality of braided filaments. Examples of suitable interventional elements <NUM> include any of those disclosed in <CIT>, <CIT>, <CIT>, and <CIT>.

The core member <NUM> can comprise a shaft, e.g., having sufficient column strength and tensile strength to facilitate moving the thrombectomy device through a catheter. The core member <NUM> can comprise a wire, which can if desired be tapered to a take on a smaller diameter as it extends distally. Such a taper can be implemented as a gradual or continuous taper, or in a plurality of discrete tapered sections separated by constant-diameter sections. The core member <NUM> can alternatively comprise a tube, such as a hypotube, and the tube/hypotube can be laser-cut with a spiral or slotted pattern, or otherwise, to impart added flexibility where desired. The core member can also comprise a combination of wires, tubes, braided shafts etc..

<FIG> illustrates an example interventional element <NUM> carrying a plurality of electrodes <NUM> thereon in a "flat" view for ease of understanding. The interventional element <NUM> illustrated in <FIG> includes a working length WL and a non-working length NWL located proximal of the working length WL. As illustrated in <FIG>, for example, the non-working length NWL is disposed between the working length WL and the connection to the core member <NUM>. In some embodiments, the interventional element <NUM> can comprise a frame or body having a plurality of struts <NUM> and a plurality of cells <NUM> located between the struts, forming a mesh. Groups of longitudinally and serially interconnected struts <NUM> can form undulating members <NUM> that extend in a generally longitudinal direction. The struts <NUM> can be connected to each other by joints <NUM>. While the struts are shown having a particular undulating or sinuous configurations, in some embodiments the struts can have other configurations. In the rolled configuration, the frame of the interventional element <NUM> can have a generally tubular or generally cylindrical shape in some embodiments, while in others the frame can have a shape that is neither tubular nor cylindrical.

The working length WL of the interventional element illustrated in <FIG> comprises some of the cells <NUM>. In embodiments wherein the interventional element <NUM> comprises cells, the cells <NUM> in the working length and the portion of the interventional element that form them can be sized and shaped such that they penetrate into a thrombus, capture a thrombus, or both upon expansion of the working length into a thrombus. In some embodiments, the portion of the interventional element <NUM> in the working length can capture the thrombus with the individual cells <NUM> and/or with an exterior, or radial exterior, of the expanded interventional element <NUM>. Additionally or alternatively, in some embodiments, the portion of the interventional element <NUM> in the working length may contact, interlock, capture or engage with a portion of the thrombus with individual cells <NUM> and/or an interior, or radial interior, of the expanded interventional element <NUM>.

As illustrated in <FIG>, for example, the non-working length NWL comprises a tapered proximal portion <NUM> of the interventional element <NUM>. The proximal portion <NUM> of the interventional element <NUM> can be tapered toward a proximal end of the interventional element <NUM>. In some embodiments, the taper of the proximal, non-working portion <NUM> can advantageously facilitate retraction and repositioning of the treatment device <NUM> and interventional element <NUM>. For example, in some embodiments, the non-working length NWL facilitates a retraction of the interventional element <NUM> into the catheter <NUM>.

The interventional element <NUM> can comprise a first edge <NUM> and a second edge <NUM>. The first edge <NUM> and second edge <NUM> can be formed, for example, from cutting a sheet or a tube. While the first and second edges are shown as having an undulating, or sinuous configuration, in some embodiments the first and second edges can have a straight, or linear configuration, or other configuration. In some embodiments, the edges <NUM>, <NUM> can be curved, straight, or a combination thereof along the tapered proximal portion <NUM>.

<FIG> also illustrates a plurality of projections <NUM>, on which an electrode <NUM> or radiopaque marker can be mounted. Each projection <NUM> can be attached to a portion of the interventional element <NUM> that may contact thrombus during use of the interventional element. In some embodiments, the projections <NUM> can be attached to portions of the interventional element <NUM> in the working length WL. In embodiments wherein the interventional element comprises struts <NUM>, the projection(s) <NUM> can be attached to strut(s) <NUM>. The projection <NUM> can be disposed within a cell <NUM>, if present, or on another surface of the interventional element <NUM>. In some embodiments, a plurality of projections <NUM> can be attached respectively to a plurality of struts <NUM>. In some embodiments, some or all of the projections <NUM> can each be attached to and/or at only a single strut <NUM>. In some embodiments, the projection <NUM> can be attached to and/or at a joint <NUM>. In some embodiments, the projections <NUM> can be separated from all other projections <NUM> by a distance, for example at least <NUM> or at least <NUM>, in a fully expanded configuration of the interventional element <NUM>. In some embodiments, the projections <NUM> can be separated from all other projections <NUM> by one cell width or one strut length (e.g., an entire length of a strut separates the adjacent projections). One or more projections <NUM> can be located at some or all of a proximal end <NUM> of the working length WL, a distal end <NUM> of the working length WL, or an intermediate area of the working length WL between the proximal end <NUM> and the distal end <NUM>. The working length WL can extend continuously or intermittently between the proximal end <NUM> and the distal end <NUM>.

In some embodiments, the interventional element <NUM> can comprise one or more distally extending tips <NUM> extending from a distal end of the interventional element <NUM>. For example, the device illustrated in <FIG> is shown comprising five elongate, distally extending tips <NUM> extending from a distal end of the interventional element <NUM>. In some embodiments wherein the interventional element comprises struts, these distal tips <NUM> can extend from a distalmost row of struts, for example as illustrated in <FIG>. In some embodiments, one or more electrodes <NUM> and/or one or more radiopaque markers can be attached to the distal tips <NUM>, if present. In some embodiments wherein one or more markers or electrodes are attached to the distal tips, the marker(s) or electrodes <NUM> on the distal tips <NUM> can be positioned at the distal end <NUM> of the working length WL, for example as illustrated in <FIG>.

As shown in <FIG>, a plurality of electrodes <NUM> can be coupled to the body of the interventional element <NUM>. Each of the electrodes <NUM> can be coupled to an electrical lead <NUM> which in turn can be coupled to the current generator (e.g., current generator <NUM>; <FIG>), or other suitable current source. Some or all of the electrodes <NUM> can take the form of electrically conductive elements affixed to portions of the interventional element <NUM>. For example, some or all of the electrodes <NUM> can be metallic, electrically conductive, and optionally radiopaque (e.g., including copper, platinum, gold, alloys thereof, or any other suitable material). In some embodiments, some or all of the electrodes <NUM> take the form of coils, bands, tubes, caps, or any other suitable structural element that can be mounted to the interventional element <NUM> and placed in electrical communication with a corresponding lead <NUM>. In some embodiments, the electrodes <NUM> can be soldered, welded, crimped, adhesively mounted or otherwise adhered to the interventional element <NUM>. As described in more detail elsewhere herein, in some embodiments at least some (or all) of the electrodes <NUM> can be in electrical communication with the body of the interventional element <NUM>, which may itself comprise an electrically conductive material (e.g., nitinol, stainless steel, etc.), such that current flows through the electrodes <NUM> and into the interventional element <NUM>. In some embodiments, at least some (or all) of the electrodes <NUM> can be carried by the interventional element <NUM> yet remain electrically insulated from the interventional element, for example by disposing an electrically insulative material between the electrode <NUM> and the body of the interventional element <NUM>. In such configurations, current flowing through such an insulated electrode <NUM> does not pass to the underlying interventional element <NUM> on which the electrode <NUM> is mounted or otherwise coupled.

As noted, each of the electrodes <NUM> can be in electrical communication with an electrical lead <NUM>. Some or all of the leads <NUM> can take the form of an elongate conductive member that is insulated along some or all of its length. For example, some or all of the leads <NUM> can take the form of conductive wires having an insulative coating along at least a portion of their lengths. Some or all of the leads can comprise other conductive structures such as traces (e.g. printed or deposited traces), tubes, buses, bars, coils, doped polymeric strands, etc. As one example, a lead <NUM> can take the form of a metallic wire (e.g., nitinol, copper, stainless steel, etc.). In some embodiments, the wire can have a thickness or diameter of between about <NUM> to about <NUM>, or between about <NUM> to about <NUM> (e.g., a <NUM> AWG wire). Such a wire may have a substantially uniform thickness along its length or may be tapered distally or proximally. The leads <NUM> can have a length of greater than about <NUM>, about <NUM>, about <NUM>, or about <NUM>. An insulative coating surrounding the wire can include any suitable electrically insulative material (e.g., polyimide, Parylene, PTFE, etc.). The leads <NUM> can be soldered, welded, or otherwise adhered to their respective electrodes <NUM>. Although some of the leads <NUM> are shown schematically in <FIG> as extending outside the body or inner lumen of the interventional element <NUM>, in various embodiments some or all of the leads <NUM> may be routed along a radially inward or radially outward surface of the interventional element <NUM>, or optionally may be routed through one or more cells <NUM>, for example in an undulating fashion such that a lead <NUM> is woven through alternating cells <NUM> in an over-under pattern. In some embodiments, a lead <NUM> may be wound (once, or multiple times) around each of one or more struts <NUM> positioned proximal of the electrode(s) coupled to the lead to more securely fasten the lead <NUM> to the body of the interventional element <NUM>.

The individual leads 204a-d can be coupled together at a proximal junction and meet in a lead bundle assembly (not shown) as described in more detail elsewhere here (e.g., with respect to <FIG>). Whether arranged in a lead bundle assembly or as discrete and separate elements, the leads 204a-d may extend proximally through a surrounding catheter (and/or be coupled to or integrated into the core member <NUM>) to be electrically coupled to the current generator or other current source.

In the illustrated embodiment of <FIG>, first and second electrodes 202a and 202b are coupled to distally extending tips <NUM>, and the first and second electrodes 202a and 202b are electrically coupled to a first electrical lead 204a, which extends proximally along the length of the interventional element <NUM>. A detailed view of the first electrode 202a mounted over a distally extending tip <NUM> is shown in <FIG>. The electrode 202a can take the form of a coil, band, cap, or tube that fits over the distally extending tip <NUM>. In various embodiments, the electrode 202a can extend around some or all of a circumference of the distally extending tip <NUM>. In some embodiments, the electrode 202a can have a length of between about <NUM> and <NUM>, or about <NUM>. In some embodiments, the electrode 202a can have a width of between about <NUM> and <NUM>, or about <NUM>. The first lead 204a can be electrically coupled to the electrode 202a. For example, the first lead 204a can be soldered, welded, or otherwise adhered to and in electrical communication with the electrode 202a. In some embodiments, a distal end portion of the lead 204a extends into the space between the electrode 202a and the distally extending tip <NUM>. According to some embodiments, the electrode 202a and/or the lead 204a may be in electrical communication with the material of the distally extending tip <NUM>. In other embodiments, an insulative material may be disposed between the electrode 202a and the distally extending tip <NUM> (and/or an insulating material may be disposed between the lead 204a and the distally extending tip <NUM>) such that current flowing through the electrode 202a and/or the lead 204a is inhibited from passing to the underlying distally extending tip <NUM> of the interventional element <NUM>.

Referring back to <FIG>, third and fourth electrodes 202c and 202d can similarly take the form of conductive (and optionally radiopaque) elements coupled to distally extending tips <NUM>. In the illustrated embodiment, the third and fourth electrodes 202c and 202d are electrically coupled to a second electrical lead 204b that extends proximally along the length of the interventional element <NUM>.

With continued reference to <FIG>, fifth and sixth electrodes 202e and 202f take the form of conductive members mounted on projections <NUM> that extend away from (and/or alongside) struts <NUM> (and/or within cells <NUM>) of the interventional element <NUM>, and a third electrical lead 204c is electrically coupled to the fifth and sixth electrodes 202e and 202f. A detailed view of the fifth electrode 202e mounted over a projection <NUM> is shown in <FIG>. The electrode 202e can take the form of a coil or band that fits over the projection <NUM>. In various embodiments, the electrode 202e can extend around some or all of a circumference of the projection <NUM>. In some embodiments, the electrode 202e can have a length of between about <NUM> and about <NUM>, for example about <NUM>. In some embodiments, the electrode 202e can have a width of between about <NUM> and <NUM>, or about <NUM>. The third lead 204c can be electrically coupled to the electrode 202e. For example, the lead 204c can be soldered, welded, or otherwise adhered to and in electrical communication with the electrode 202e. In some embodiments, a distal end portion of the lead 204c extends into the space between the electrode 202e and the projection <NUM>. According to some embodiments, the electrode 202e and/or the lead 204c may be in electrical communication with the material of the projection <NUM>. In other embodiments, an insulative material may be disposed between the electrode 202e and the projection <NUM> (and/or an insulating material may be disposed between the lead 204c and the projection <NUM>) such that current flowing through the electrode 202e and/or the lead 204c is inhibited from passing to the underlying projection <NUM> of the interventional element <NUM>.

Referring back to <FIG>, seventh and eighth electrodes <NUM> and <NUM> can similarly take the form of conductive (and optionally radiopaque) elements coupled to projections <NUM>. In the illustrated embodiment, the seventh and eighth electrodes <NUM> and <NUM> are electrically coupled to a fourth electrical lead 204d that extends proximally along the length of the interventional element <NUM>.

In the example shown in <FIG>, there are four discrete electrical leads <NUM> each coupled to two electrodes <NUM>, for a total of eight addressable electrodes <NUM>. This configuration is only exemplary; in other embodiments there may be fewer or more electrodes (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or more electrodes carried by the interventional element <NUM>). Similarly, there may be fewer or more leads <NUM>.

By selecting the positioning of the individual electrodes <NUM>, the electrical charge distribution over the interventional element <NUM> can be tailored to achieve the desired results during treatment. For example, by coupling electrodes 202e, 202f, <NUM>, and <NUM> to the positive terminal of a current generator (e.g., by coupling leads 204c and 204d to the positive terminal of a current generator), these electrodes 202e, 202f, <NUM>, and <NUM> can deliver positive electrical charge to respective portions of the interventional element <NUM>. As such, these may serve as delivery electrodes. If any of these electrodes are in electrical communication with the interventional element <NUM>, this positive current may flow into the interventional element <NUM>, thereby positively charging a greater portion of the surface of the interventional element <NUM>. In some embodiments, a portion of the interventional element <NUM> can be coated with an electrically insulative material so as to selectively concentrate electrical charge in certain regions (e.g., within the working length WL). In accordance with some embodiments, some or all of the delivery electrodes 202e, 202f, <NUM>, and <NUM> are not in electrical communication with the interventional element <NUM> (e.g., due to the presence of an insulative material disposed between the delivery electrodes and their respective projections <NUM>).

In some embodiments, an electrode <NUM> coupled to a projection <NUM> located at the proximal end <NUM> of the working length WL can be disposed within <NUM>, within <NUM>, within <NUM>, within <NUM>, or within <NUM>, proximally or distally, of the proximal end <NUM>. In some embodiments, an electrode <NUM> coupled to a projection <NUM> located at the proximal end <NUM> can be disposed within the length of one cell or one strut, proximally or distally, of the proximal end <NUM>.

In some embodiments, an electrode <NUM> coupled to a projection <NUM> located at the distal end <NUM> of the working length WL can be disposed within <NUM>, within <NUM>, within <NUM>, within <NUM>, or within <NUM>, proximally or distally, of the distal end <NUM>. In some embodiments, an electrode coupled to a projection <NUM> located at the distal end <NUM> can be disposed within the length of one cell or one strut, proximally or distally, of the distal end <NUM>.

In addition to electrode positioning, the charge distribution is affected by the configuration of the delivery electrodes (e.g., material, size, surface area), the delivery leads (e.g., material, cross-sectional size) and the amount of current delivered. For example, a decreased number or surface area of the electrodes results in increased charge density at the electrodes. If the charge density is too high, it may present health risks when used in the body. However, at certain thresholds of charge density, hydrogen gas can be generated at the electrodes <NUM> or on other portions of the interventional element <NUM>. In some instances, hydrogen gas can be neuroprotective, and accordingly it can be advantageous to provide a selective high enough charge density to generate hydrogen gas within the patient's neurovasculature.

In the illustrated embodiment, the distally positioned electrodes 202a, 202b, 202c, and 202d are coupled to the negative terminal of a current generator (e.g., by coupling leads 204a and 204b to the negative terminal of a current generator) and accordingly these electrodes serve as return electrodes. In some embodiments, the return electrodes may be electrically insulated from the interventional element <NUM>, for example by disposing an insulative material between the distally extending tips <NUM> and the respective electrodes 202a, 202b, 202c, and/or 202d.

In operation, an electrical circuit is provided in which current flows from the positive terminal of the current generator, distally through the delivery leads 204c and 204d to delivery electrodes 202e, 202f, <NUM>, and <NUM>, and to the interventional element <NUM> (if one or more of the delivery electrodes are in electrical communication with the interventional element <NUM>). Current then passes from the surface of the interventional element <NUM> and/or from the delivery electrodes and to the surrounding media (e.g., blood, tissue, thrombus, etc.) before returning back to the return electrodes 202a, 202b, 202c, and 202d. The current then flows proximally through the return leads 204a and 204b, and back to the negative terminal of the current generator. Alternatively, the return electrode(s) can be provided elsewhere, for example via an external needle or grounding pad, via an insulated guidewire with an exposed distal portion or an exposed electrode portion of the core member <NUM>, coupled to a distal portion of a catheter, etc. In such cases, the return electrode(s) may optionally be omitted from the interventional element <NUM>.

In some embodiments, the non-working length NWL portion of the interventional element <NUM> can be coated with a non-conductive or insulative material (e.g., Parylene, PTFE, or other suitable non-conductive coating) such that the coated region is not in electrical contact with the surrounding media (e.g., blood). As a result, the current carried by the delivery electrodes <NUM> to the interventional element <NUM> is only exposed to the surrounding media along the working length WL portion of the interventional element <NUM>. This can advantageously concentrate the electrically enhanced attachment effect along the working length WL of the interventional element <NUM>, where it is most useful, and thereby combine both the mechanical interlocking provided by the working length WL and the electrical enhancement provided by the delivered electrical signal. In some embodiments, a distal region of the interventional element <NUM> (e.g. distal of the working length WL) may likewise be coated with a non-conductive material (e.g., Parylene, PTFE, or other suitable non-conductive coating), leaving only a central portion or the working length WL of the interventional element <NUM> having an exposed conductive surface.

In some embodiments, the proximal end of the working length can be at a proximalmost location where the interventional element forms a complete circumference. In some embodiments, the proximal end of the working length can be at a proximalmost location where the interventional element has its greatest transverse dimension in a fully expanded state. In some embodiments, the proximal end of the working length can be at a proximalmost location where the interventional element has a peak, crown, or crest in transverse dimension in a fully expanded state.

In some embodiments, the distal end of the working length can be at a distalmost location where the interventional element forms a complete circumference. In some embodiments, the distal end of the working length can be at a distalmost location where the interventional element has its greatest transverse dimension in a fully expanded state. In some embodiments, the distal end of the working length can be at a distalmost location where the interventional element has a peak, crown, or crest in transverse dimension in a fully expanded state.

In some embodiments, the interventional element <NUM> may include a conductive material positioned on some or all of its outer surface. The conductive material, for example, can be gold and/or another suitable conductor that has a conductivity greater than (or a resistivity less than) that of the material comprising the interventional element <NUM>. The conductive material may be applied to the interventional element <NUM> via electrochemical deposition, sputtering, vapor deposition, dip-coating, and/or other suitable means. In some aspects of the present technology, a conductive material is disposed only on the working length WL portion of the interventional element <NUM>, e.g., such that the proximal and distal end portions of the interventional element <NUM> are exposed or not covered in the conductive material. In such configurations, because the conductive material has a much lower resistance than the underlying material comprising the interventional element <NUM>, current delivered to the interventional element <NUM> is concentrated along the working length WL portion. In several of such embodiments, the conductive material may be disposed on only a radially outwardly facing strut surface along the working length WL portion. In other embodiments, the conductive material may be disposed on all or a portion of the strut surface along all or a portion of the length of the interventional element <NUM>.

In some embodiments, a first portion of the interventional element <NUM> is covered by a conductive material and a second portion of the interventional element <NUM> is covered by an insulative or dielectric material (e.g., Parylene). For example, in some embodiments a radially outwardly facing surface of the strut surface is covered by a conductive material while a radially inwardly facing surface of the strut surface is covered by an insulative material. In some embodiments, the working length WL portion of the interventional element <NUM> may be covered by a conductive material while the non-working length NWL portion is covered by an insulative material. In some embodiments, the conductive material may be disposed on all or a portion of the strut surface along all or a portion of the length of the interventional element <NUM>, and the insulative material may be disposed on those portions of the strut surface and/or working length not covered by the conductive material.

<FIG> illustrates another example interventional element <NUM> carrying a plurality of electrodes <NUM> thereon in a "flat" view for ease of understanding. The configuration shown in <FIG> can be similar to that described previously with respect to <FIG>, except that, as shown in <FIG>, there are four leads 204a-d coupled respectively to four electrodes 202a-d. The first electrode 202a and the fourth electrode 202d take the form of conductive members coupled to a strut <NUM> of the interventional element <NUM>, whereas the second electrode 202b and the third electrode 202c take the form of conductive members coupled to projections <NUM>, similar to those described above with respect to <FIG>.

A detailed view of the fourth electrode 202d mounted over the strut <NUM> is shown in <FIG>. The electrode 202d can take the form of a coil, band, cap, or tube that fits over the strut <NUM>. In various embodiments, the electrode 202d can extend around some or all of a circumference of the strut <NUM>. The fourth lead 204d can be electrically coupled to the fourth electrode 202d. For example, the lead 204d can be soldered, welded, or otherwise adhered to and in electrical communication with the electrode 202d. In some embodiments, a distal end portion of the lead 204d extends into the space between the electrode 202d and the strut <NUM>. According to some embodiments, the electrode 202d and/or the lead 204d may be in electrical communication with the material of the strut <NUM>. In other embodiments, an insulative material may be disposed between the electrode 202e and the strut <NUM> (and/or an insulating material may be disposed between the lead 204d and the strut <NUM>) such that current flowing through the electrode 202d and/or the lead 204d is inhibited from passing to the underlying strut <NUM> of the interventional element <NUM>.

Referring back to <FIG>, the electrodes <NUM> can be coupled to terminals of a current generator via their respective leads <NUM> such that the second electrode 202b and the fourth electrode 202d serve as delivery electrodes (e.g., coupled to the positive terminal) and the first electrode 202a and the third electrode 202c serve as return electrodes (e.g., coupled to the negative terminal). In contrast to the configuration of <FIG>, in which delivery electrodes were disposed over a central portion of the interventional element <NUM> and return electrodes were positioned along distal tips, in the embodiment shown in <FIG> the return and delivery electrodes are both positioned over central portions (e.g., within the working length WL) of the interventional element <NUM>. This configuration can provide a different charge distribution over the surface of the interventional element <NUM>, for example by providing a shorter path between the delivery and return electrodes. Additionally, as shown in <FIG>, at least one delivery electrode 202d is positioned distally of at least one return electrode 202c, while at least one delivery electrode 202b is also positioned proximally of at least one return electrode 202a.

The embodiments shown in <FIG> and <FIG> illustrate exemplary configurations of electrodes <NUM> and leads <NUM>, however various other configurations are possible. For example, some or all of the electrodes can be mounted to the interventional element <NUM> at any suitable location, for example along a strut <NUM>, a projection <NUM>, a distally extending tip <NUM>, or any other suitable position. Similarly, the number of electrodes <NUM>, their respective polarities, and their relative positioning can be selected to achieve the desired charge distribution and other operating parameters.

<FIG> illustrate cross-sectional views of electrodes <NUM> mounted on interventional elements <NUM> with an intervening insulative material <NUM> disposed between the electrode <NUM> and the underlying portion of the interventional element in each instance. In the embodiment of <FIG>, the portion of the interventional element <NUM> underlying the electrode <NUM> has a rectangular cross-section (for example, the strut <NUM>), whereas in the embodiment of <FIG>, the portion of the interventional element <NUM> underlying the electrode <NUM> has a circular cross-section (for example, the distally extending tip <NUM>). These shapes are only exemplary, and in various embodiments the interventional element <NUM> can assume any suitable cross-sectional shape. In both <FIG>, the electrode <NUM> surrounds the segment of the interventional element <NUM>, with an insulative material <NUM> disposed therebetween. The insulative material <NUM> can be, for example, Parylene, PTFE, polyimide, or any suitable electrically insulative material. As a result, current carried by the electrode <NUM> is not passed to the strut <NUM> or distally extending tip <NUM>. Such insulated configurations may be employed for either delivery or return electrodes, as desired.

<FIG> illustrates cross-sectional views of electrodes <NUM> mounted on interventional elements <NUM> so as to be in electrical communication with the interventional elements <NUM>. Here there is no intervening insulative material, such that the electrode <NUM> is in direct contact and therefore in electrical communication with the underlying strut <NUM> or the distally extending tip <NUM> of the interventional element <NUM>. In some embodiments one or more non-insulative (e.g., conductive) coatings can be disposed between the electrode <NUM> and the strut <NUM> or the distally extending tip <NUM> of the interventional element <NUM>. In this configuration, current delivered to the electrode <NUM> passes to the underlying strut <NUM> or distally extending tip <NUM> of the interventional element <NUM>, particularly if the interventional element <NUM> is made of an electrically conductive material such as stainless steel or nitinol. Such electrically coupled configurations may be employed for either delivery or return electrodes, as desired.

<FIG> illustrate additional embodiments of interventional elements <NUM>, <NUM>, <NUM> carrying a plurality of electrodes <NUM> thereon, which interventional elements and electrode arrangements can be similar to the various embodiments of the interventional element <NUM> and associated electrode arrangements described herein, except as otherwise specified. A plurality of leads (not shown) can be electrically coupled to the electrodes <NUM> to provide an electrical connection between a current generator and the individual electrodes <NUM> as described elsewhere herein. As shown in <FIG>, the interventional elements can take a number of different forms while benefiting from the electrically enhanced adhesion to clot material provided by the electrodes <NUM>. For example, with respect to <FIG>, the interventional element <NUM> is a clot retrieval device with an inner tubular member and an outer expandable member having a greater diameter than the inner tubular member. The outer member can have radially outwardly extending struts defining inlet mouths configured to receive clot material therein. With respect to <FIG>, the interventional element <NUM> is another example of a clot retrieval device, in this instance comprising a plurality of interlinked cages having atraumatic leading surfaces and configured to expand radially outwardly to engage a thrombus. <FIG> illustrates another example interventional element <NUM> in the form of a clot retrieval device, here comprising a coiled or helical member configured to be expanded into or distal to a thrombus, thereby engaging the thrombus between turns of the coil and facilitating removal from the body. In addition to these illustrative examples, the interventional element <NUM> can take other forms, for example a removal device, a thrombectomy device, a retrieval device, a braid, a mesh, a laser-cut stent, or any suitable structure.

As noted above, electrodes <NUM> carried by the interventional element <NUM> can be electrically coupled to an extracorporeal current generator <NUM> via longitudinally extending leads <NUM>, which can be coupled or joined together via a proximally extending lead bundle assembly <NUM>. In various embodiments, the lead bundle assembly <NUM> can extend parallel to but separate from the core member <NUM>, or in some embodiments the lead bundle assembly can be coupled to or integrated with the core member <NUM>. The leads <NUM> can be configured to be electrically coupled at their respective proximal end portions to a current generator (e.g., current generator <NUM>; <FIG>) or other current source and to couple at their respective distal ends to one or more of the electrodes <NUM> coupled to the interventional element <NUM> as described elsewhere herein. In some embodiments, the leads <NUM> include both delivery electrode leads and return electrode leads, while in other embodiments the leads <NUM> include only delivery electrode leads, in which case one or more return electrodes can be separately coupled to a current generator (for example via an external needle or grounding pad, by being coupled to a catheter, or any other suitable configuration). Similarly, in some embodiments the leads <NUM> include only return electrode leads, with only return electrodes <NUM> carried by the interventional element <NUM>. In such configurations, the delivery electrode may be provided elsewhere, for example coupled to a distal portion of a catheter, carried by another portion of the interventional element, or any other suitable arrangement.

<FIG> is a side cross-sectional view of a lead bundle assembly <NUM> in accordance with some embodiments, and <FIG> is a cross-sectional view of the assembly <NUM> shown in <FIG>. As shown in <FIG>, the lead bundle assembly <NUM> includes four leads 204a-d extending longitudinally along the assembly <NUM>. Although four leads are shown, in various embodiments there may be more or fewer leads, for example <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or more leads. The lead bundle assembly <NUM> can have a length sufficient to extend between an extracorporeal current generator at a proximal end and an intravascular treatment site at the distal end. For example, the lead bundle assembly <NUM> can have a length of at least about <NUM>, at least about <NUM>, at least about <NUM>, or at least about <NUM>, or a length of between about <NUM> and <NUM>, or between about <NUM> and about <NUM>.

The leads <NUM> can each be exposed (e.g., not covered with insulative material) at a proximal end portion of the assembly <NUM> for coupling to a current generator (e.g., current generator <NUM>; <FIG>). At a distal end portion of the lead bundle assembly <NUM>, the leads <NUM> can extend distally away from the bundle assembly <NUM> separately, with each lead <NUM> extending towards a different electrode. This distally extending portion of the leads <NUM> (not shown here) can include an insulative material disposed over the individual leads <NUM>, with an exposed distal end portion (e.g., leaving approximately <NUM>-<NUM> exposed) to facilitate coupling individual leads <NUM> to individual electrodes, as described above with respect to <FIG>.

In at least some embodiments, the lead bundle assembly <NUM> includes a first insulating layer or material <NUM> extending around each of the leads <NUM>. The first insulating material <NUM> can be, for example, polyimide any other suitable electrically insulating coating (e.g., PTFE, oxide, ETFE-based coatings, or any suitable dielectric polymer). The first insulating material <NUM> can circumferentially surround each lead <NUM>, for example having a thickness of between about <NUM>" and about <NUM>", or about <NUM>". In some embodiments, the first insulating material <NUM> extends along substantially the entire length of the leads <NUM> and the assembly <NUM>. In some embodiments, the first insulating material <NUM> separates and electrically insulates leads <NUM> from one another along substantially the entire length of the assembly <NUM>. In some embodiments, the first insulating material <NUM> does not cover the proximal-most portion of the leads <NUM>, providing an exposed region of the leads <NUM> to which the current generator <NUM> (<FIG>) can be electrically coupled. In some embodiments, the first insulating material <NUM> does not cover the distal-most portion of the leads <NUM>, providing an exposed region of the leads <NUM> to which an electrode <NUM> (<FIG>) can be electrically coupled.

The lead bundle assembly <NUM> can additionally include a second insulating layer or material <NUM> surrounding some or all of the leads <NUM> along at least a portion of their respective lengths. The second insulating material <NUM> can be, for example, polyimide, or any other suitable electrically insulative coating (e.g., PTFE, oxide, ETFE based coatings or any suitable dielectric polymer). The insulating material <NUM> can take the form of a substantially tubular member having a wall thickness of between about <NUM>" and about <NUM>", or about <NUM>". In some embodiments, the second insulating material <NUM> does not cover the proximal-most portion of leads <NUM>, providing an exposed region of the leads <NUM> to which the current generator <NUM> (<FIG>) can be electrically coupled. Distal to a distal end of the second insulating material <NUM>, the individual leads <NUM> (and optionally the surrounding first insulative material <NUM>) can extend distally towards individual electrodes <NUM>, as noted previously.

In the embodiment of <FIG>, the second insulating material <NUM> defines an outer surface of the bundle assembly <NUM>, which can be substantially cylindrical. In use, the bundle assembly <NUM> can be slidably advanced through a catheter (e.g., third catheter <NUM>; <FIG>) alongside the core member <NUM>. In some embodiments, the bundle assembly <NUM> can be coupled to the core member <NUM>, for example being adhered together at one or more positions to prevent relative slidable movement. In other embodiments, the bundle assembly <NUM> and the core member <NUM> can remain separate and slidable and/or rotatable with respect to one another.

<FIG> is a side cross-sectional view of a lead bundle assembly <NUM> in accordance with another embodiment, and <FIG> is a cross-sectional view of the assembly <NUM> shown in <FIG>. In this embodiment, two leads 204a and 204b are embedded within an insulative ribbon <NUM>. The ribbon can be made of an electrically insulative material, for example, polyimide, Parylene, PTFE, or any other suitable electrically insulative material, and can leave proximal and distal portions of the leads 204a and 204b exposed as described previously. As shown in <FIG>, the ribbon can have a substantially rectangular cross-section. The ribbon can have a thickness of between about <NUM>" to about <NUM>" and a width of less than about <NUM>".

Generally, the lead bundle assemblies depicted in <FIG> can serve as the core member <NUM> without any additional structures or components, or with added structures such as a non-conducting core wire or shaft, a braided shaft or a surrounding (or central) tube, coil or braid. Such a tube can be laser-cut with a spiral or slotted pattern, or otherwise, to impart added flexibility where desired.

<FIG> is a side cross-sectional view of a lead bundle assembly <NUM> in accordance with another embodiment, and <FIG> is a cross-sectional view of the assembly <NUM> shown in <FIG>. This embodiment can be similar to that of <FIG>, except that the assembly <NUM> is coaxially arranged around the core member <NUM> (which can comprise a wire, tube, braided shaft, etc. as described above). For example, each lead 204a-d can be coated with a first insulative material <NUM> as described above with respect to <FIG>. However, in this embodiment, the leads <NUM> are disposed radially around the core member <NUM>, and the surrounding second insulative material <NUM> envelops both the leads <NUM> and the core member <NUM>. As a result, the core member <NUM> and the leads <NUM> can be fixedly secured with respect to one another, and they can be slidably advanced through a surrounding catheter as a single unit.

Figures 17A to <NUM> illustrate a method of removing clot material CM from the lumen of a blood vessel V using the treatment system <NUM> of the present technology. As shown in <FIG>, the first catheter <NUM> can be advanced through the vasculature and positioned within the blood vessel such that a distal portion of the first catheter <NUM> is proximal of the clot material CM. As shown in <FIG>, the second catheter <NUM> may be advanced through the first catheter <NUM> until a distal portion of the second catheter <NUM> is at or proximal to the clot material CM. Next, the third catheter <NUM> may be advanced through the second catheter <NUM> so that a distal portion of the third catheter <NUM> is positioned at or near the clot material CM. In some embodiments, the third catheter <NUM> may be positioned such that a distal terminus of the third catheter <NUM> is distal of the clot material CM. The interventional element <NUM> may then be advanced through the third catheter <NUM> in a low-profile configuration until a distal terminus of the interventional element <NUM> is at or adjacent the distal terminus of the third catheter <NUM>.

As shown in <FIG>, the third catheter <NUM> may be withdrawn proximally relative to the interventional element <NUM> to release the interventional element <NUM>, thereby allowing the interventional element <NUM> to self-expand within the clot material CM. As the interventional element <NUM> expands, the interventional element <NUM> engages and/or secures the surrounding clot material CM, and in some embodiments may restore or improve blood flow through the clot material CM by pushing open a blood flow path therethrough. In some embodiments, the interventional element <NUM> may be expanded distal of the clot material CM such that no portion of the interventional element <NUM> is engaging the clot material CM while the interventional element <NUM> is in the process of expanding toward the vessel wall. In some embodiments, the interventional element <NUM> is configured to expand into contact with the wall of the vessel V, or the interventional element <NUM> may expand to a diameter that is less than that of the blood vessel lumen such that the interventional element <NUM> does not engage the entire circumference of the blood vessel wall.

Once the interventional element <NUM> has been expanded into engagement with the clot material CM, the interventional element <NUM> may grip the clot material CM by virtue of its ability to mechanically interlock with the clot material CM. The current generator <NUM>, which is electrically coupled to the proximal end of the leads <NUM>, can deliver a current to electrodes <NUM> carried by the interventional element <NUM> before or after the interventional element <NUM> has been released from the third catheter <NUM> into the blood vessel and/or expanded into the clot material CM. The interventional element <NUM> can be left in place or manipulated within the vessel V for a desired time period while the electrical signal is being delivered. Positive current delivered to the interventional element <NUM> via the electrodes <NUM> can attract negatively charged constituents of the clot material CM, thereby enhancing the grip of the interventional element <NUM> on the clot material CM. This allows the interventional element <NUM> to be used to retrieve the clot material CM with reduced risk of losing grip on the thrombus or a piece thereof, which can migrate downstream and cause additional vessel blockages in areas of the brain that are more difficult to reach.

In some methods of the present technology, a guidewire (not shown) may be advanced to the treatment site and pushed through the clot material CM until a distal portion of the guidewire is distal of the clot material CM. The guidewire may be advanced through one or more of the catheters <NUM>-<NUM> and/or one or more of the catheters <NUM>-<NUM> may be advanced over the guidewire. The guidewire may be insulated along at least a portion of its length (e.g., with Parylene, PTFE, etc.), with exposed portions permitting electrical communication with the current generator <NUM> and the interventional element <NUM>. For example, in some embodiments a distal portion of the guidewire may be exposed, and the guidewire may be positioned at the treatment site such that the exposed portion of the guidewire is distal of the clot material CM. A proximal end of the guidewire may be coupled to the current generator such that the exposed portion of the guidewire functions as a return electrode. In some embodiments, the guidewire may be coupled to the positive terminal of the power source and the exposed portion functions as a delivery electrode. The guidewire may be used as a delivery or return electrode with any delivery or return electrode carried by any component of the treatment system (e.g., one or more of the first-third catheters <NUM>, <NUM>, <NUM>, the interventional element <NUM>, etc.).

In some methods, fluid may be delivered to the treatment site via the second catheter <NUM> and/or third catheter <NUM> while current is being delivered to the interventional element <NUM>. Fluid delivery may occur before or while the interventional element <NUM> is engaging the thrombus, and may coincide with the entire duration of current delivery or just a portion thereof. In some instances, aspiration may be applied to the treatment site via the second catheter <NUM>. For example, following deployment of the interventional element <NUM>, the third catheter <NUM> can be retracted and removed from the lumen of the second catheter <NUM>. The treatment site can then be aspirated via the second catheter <NUM>, for example via a suction source such as a pump or syringe coupled to a proximal portion of the second catheter <NUM>. In some embodiments, following expansion of the interventional element <NUM>, the treatment site is aspirated concurrently with supplying electrical energy to the interventional element <NUM> via the current generator <NUM>. By combining aspiration with the application of electrical energy, any newly formed clots (e.g., any clots formed that are attributable at least in part to the application of electrical energy), or any clot pieces that are broken loose during the procedure, can be pulled into the second catheter <NUM>, thereby preventing any such clots from being released downstream of the treatment site. As a result, concurrent aspiration may permit the use of higher power or current levels delivered to the interventional element <NUM> without risking deleterious effects of new clot formation. Additionally, aspiration can capture any gas bubbles formed along the interventional element <NUM> during application of electrical energy to the interventional element <NUM>, which can improve patient safety during the procedure.

In some embodiments, aspiration is applied while the interventional element <NUM> is retracted into the second catheter <NUM>. Aspiration at this stage can help secure the clot material CM within the second catheter <NUM> and prevent any dislodged portion of the clot material CM from escaping the second catheter <NUM> and being released back into the vessel V. In various embodiments, the treatment site can be aspirated continuously before, during, or after delivering electrical signals to the interventional element <NUM> as well as before, during, or after retraction of the interventional element <NUM> into the second catheter <NUM>.

At any time before, during, and/or after deployment of the interventional element <NUM>, a flow arrest element (e.g., a balloon of a balloon-guide catheter or other suitable flow arrest element) may be deployed within the blood vessel proximal of the clot material CM to partially or completely arrest blood flow to the treatment site. In some methods, the flow arrest element may be deployed at a location along the blood vessel proximal of the clot material CM (for example, at a proximal portion of the internal carotid artery) and may remain inflated as the interventional element <NUM> is deployed and eventually withdrawn to remove the thrombus.

At least while the interventional element <NUM> is deployed and engaging the thrombus CM, electric current may be delivered to the interventional element <NUM> (e.g., via leads <NUM> and electrodes <NUM>) to positively charge the interventional element <NUM>, thereby enhancing clot adhesion to the interventional element <NUM>. With reference to <FIG>, while the interventional element <NUM> is engaged with the clot material CM, the clot material CM can be removed. For example, the interventional element <NUM>, with the clot material CM gripped thereby, can be retracted proximally (for example, along with the second catheter <NUM> and, optionally, the third catheter <NUM>). The second catheter <NUM>, interventional element <NUM>, and associated clot material CM may then be withdrawn from the patient, optionally through one or more larger surrounding catheters. During this retraction, the interventional element <NUM> can grip the clot material CM electrically and/or electrostatically, e.g., via the application of current from a current generator as discussed herein. (As used herein with reference to gripping or retrieving thrombus or other vascular/luminal material, or to apparatus for this purpose, "electrical" and its derivatives will be understood to include "electrostatic" and its derivatives. ) Accordingly, the interventional element <NUM> can maintain an enhanced or electrically and/or electrostatically enhanced grip on the clot material CM during retraction. In other embodiments, the current generator <NUM> may cease delivery of electrical signals to the electrodes <NUM> carried by the interventional element <NUM> prior to retraction of the interventional element <NUM> with respect to the vessel V. In some embodiments, the interventional element <NUM> and clot material CM form a removable, integrated thrombus-device mass wherein the connection of the thrombus to the device is electrically enhanced, e.g. via the application of current as discussed herein.

<FIG> show various electrical waveforms for use with the treatment systems of the present technology. Although the waveforms and other power delivery parameters disclosed herein can be used with the devices and methods described above with respect to <FIG>, the waveforms and other parameters are also applicable to other device configurations and techniques. For example, the return electrode can be provided along the catheter wall, as a separate conductive member extending within the catheter lumen, as a needle electrode provided elsewhere in the body, etc. In each of these device configurations, the power delivery parameters and waveforms can be beneficially employed to promote clot adhesion without damaging surrounding tissue. Additionally, although the waveforms and other power delivery parameters disclosed herein may be used for treating a cerebral or intracranial embolism, other applications and other embodiments in addition to those described herein are within the scope of the technology. For example, the waveforms and power delivery parameters disclosed herein may be used to electrically enhance removal of emboli from body lumens other than blood vessels (e.g., the digestive tract, etc.) and/or may be used to electrically enhance removal of emboli from blood vessels outside of the brain (e.g., pulmonary blood vessels, blood vessels within the legs, etc.).

As noted above, the treatment system can include a plurality of delivery electrodes and/or a plurality of return electrodes carried by an interventional element. In some embodiments, two or more delivery electrodes can be driven with the same waveforms. However, in some embodiments, two or more delivery electrodes can be driven with different waveforms to achieve the desired charge distribution characteristics at the interventional element <NUM>.

While applying a continuous uniform direct current (DC) electrical signal (as shown in <FIG>) to positively charge the interventional element can improve attachment to the thrombus, this can risk damage to surrounding tissue (e.g., ablation), and sustained current at a relatively high level may also be thrombogenic (i.e., may generate new clots). For achieving effective clot-grabbing without ablating tissue or generating substantial new clots at the treatment site, periodic waveforms have been found to be particularly useful. Without wishing to be bound by theory, the clot-adhesion effect appears to be most closely related to the peak current of the delivered electrical signal. Periodic waveforms can advantageously provide the desired peak current without delivering excessive total energy or total electrical charge. Periodic, non-square waveforms in particular are well suited to deliver a desired peak current while reducing the amount of overall delivered energy or charge as compared to either uniform applied current or square waveforms.

<FIG> illustrate various periodic waveforms that can be used with the devices and methods described above with respect to <FIG>, as well as with other devices and techniques. <FIG> illustrates a continuous uniform DC electrical signal which can also be used in some embodiments. Referring to <FIG>, electrical power can be delivered according to these waveforms as pulsed direct current. <FIG> illustrate periodic square and triangular waveforms, respectively. These two waveforms have the same amplitude, but the triangular waveform is able to deliver the same peak current as the square waveform, with only half of the total charge delivered, and less total energy delivered. <FIG> illustrates another pulsed-DC or periodic waveform which is a composite of a square waveform and a triangular waveform. This superposition of a triangular waveform and a square waveform shown in <FIG> delivers additional efficacy compared to the triangular waveform of <FIG> while nonetheless delivering less overall energy than the square waveform of <FIG>. This is because the delivered energy is proportional to the square of current and the brief high peak in the composite waveform of <FIG> ensures that current is supplied without dispensing excessive energy. <FIG> illustrates yet another non-square waveform, in this case a trapezoidal waveform in which "ramp-up" and "ramp-down" portions at the beginning and end of each pulse provide periods of reduced current compared to square waveforms. In other embodiments, different non-square waveforms can be used, including a superposition of a square waveform with any non-square waveform, depending on the desired power delivery characteristics.

The waveform shape (e.g., pulse width, duty cycle, amplitude) and length of time can each be selected to achieve desired power delivery parameters, such as overall electrical charge, total energy, and peak current delivered to the interventional element and/or catheter. In some embodiments, the overall electrical charge delivered to the interventional element and/or catheter can be between about <NUM>-<NUM> mC, or between about <NUM>-<NUM> mC. According to some embodiments, the total electrical charge delivered to the interventional element and/or catheter may be less than <NUM> mC, less than <NUM> mC, less than <NUM> mC, less than <NUM> mC, less than <NUM> mC, or less than <NUM> mC.

In some embodiments, the total energy delivered to the interventional element and/or aspiration catheter can be between about <NUM>-<NUM>,<NUM> mJ, or between about <NUM>-<NUM>,<NUM> mJ, or between about <NUM>-<NUM> mJ. According to some embodiments, the total energy delivered to the interventional element and/or aspiration catheter may be less than <NUM>,<NUM> mJ, less than <NUM>,<NUM> mJ, less than <NUM>,<NUM> mJ, less than <NUM>,<NUM> mJ, less than <NUM>,<NUM> mJ, less than <NUM>,<NUM> mJ, less than <NUM>,<NUM> mJ, less than <NUM> mJ, less than <NUM>,<NUM> mJ, less than <NUM> mJ, less than <NUM> mJ, less than <NUM> mJ, less than <NUM> mJ, less than <NUM> mJ, less than <NUM> mJ, less than <NUM> mJ, or less than <NUM> mJ, or less than <NUM> mJ, or less than <NUM> mJ, or less than <NUM> mJ, or less than <NUM> mJ, or less than <NUM> mJ, or less than <NUM> mJ, or less than <NUM> mJ.

In some embodiments, the peak current delivered can be between about <NUM>-<NUM> mA, or between about <NUM>-<NUM> mA. According to some embodiments, the peak current delivered may be greater than <NUM> mA, greater than <NUM> mA, greater than <NUM> mA, greater than <NUM> mA, greater than <NUM> mA, or greater than <NUM> mA.

The duration of power delivery is another important parameter that can be controlled to achieve the desired clot-adhesion effects without damaging tissue at the treatment site or generating new clots. In at least some embodiments, the total energy delivery time can be no more than <NUM> minute, no more than <NUM> minutes, no more than <NUM> minutes, no more than <NUM> minutes, or no more than <NUM> minutes. According to some embodiments, the total energy delivery time may be less about <NUM> seconds, less than about <NUM> minute, less than about <NUM> seconds, or less than about <NUM> minutes. As used herein, the "total energy delivery time" refers to the time period during which the waveform is supplied to the interventional element and/or catheter (including those periods of time between pulses of current).

The duty cycle of the applied electrical signal can also be selected to achieve the desired clot-adhesion characteristics without ablating tissue or promoting new clot formation. In some embodiments, the duty cycle can be between about <NUM>% about <NUM>% or between about <NUM>% to about <NUM>%. According to some embodiments, the duty cycle may be about <NUM>%, about <NUM>%, about <NUM>%, about <NUM>%, or about <NUM>%. In yet other embodiments, a constant current may be used, in which the duty cycle is <NUM>%. For <NUM>% duty cycle embodiments, a lower time or current may be used to avoid delivering excess total energy to the treatment site.

Table <NUM> presents a range of values for power delivery parameters of different waveforms. For each of the conditions set forth in Table <NUM>, a resistance of <NUM> kohm and a frequency of <NUM> (for the Square, Triangle, and Composite conditions) was used. The Constant conditions represent a continuous and steady current applied for the duration, i.e. <NUM>% duty cycle. The Peak Current <NUM> column represents the peak current for the corresponding waveform. For the Composite conditions, the Peak Current <NUM> column indicates the peak current of the second portion of the waveform. For example, referring back to <FIG>, Peak Current <NUM> would correspond to the current at the top of the triangular portion of the waveform, while Peak Current <NUM> would correspond to the current at the top of the square portion of the waveform.

As seen in Table <NUM>, the periodic waveforms (Square, Triangle, and Composite conditions) achieve higher peak currents with lower overall charge delivered than the corresponding Constant conditions. For example, in condition Constant <NUM>, a peak current of <NUM> mA corresponds to a total energy delivered of <NUM>,<NUM> mJ, while condition Square <NUM> delivers a peak current of <NUM> mA with a total energy of only <NUM>,<NUM> mJ. Conditions Triangle <NUM> and Composite <NUM> similarly deliver lower total energy while maintaining a peak current of <NUM> mA. Since clot-adhesion appears to be driven by peak current, these periodic waveforms can therefore offer improved clot adhesion while reducing the risk of damaging tissue at the treatment site or promoting new clot formation. Table <NUM> also indicates that the Triangle and Composite conditions achieve higher peak currents with lower overall charge delivered than the corresponding Square conditions. For example, condition Square <NUM> has a peak current of <NUM> mA and a total charge delivered of <NUM> mC, while condition Triangle <NUM> has a peak current of <NUM> mA but a total charge delivered of only <NUM> mC, and condition Composite <NUM> has a peak current of <NUM> mA and a total charge delivered of only WL mC. As such, these non-square waveforms provide additional benefits by delivering desirable peak current while reducing the overall charge delivered to the treatment site.

Although Table <NUM> represents a series of waveforms with a single frequency (<NUM>), in some embodiments the frequency of the pulsed-DC waveforms can be controlled to achieve the desired effects. For example, in some embodiments the frequency of the waveform can be between <NUM> and <NUM>, between <NUM> and <NUM>, or between <NUM> to <NUM>.

This disclosure is not intended to be exhaustive or to limit the present technology to the precise forms disclosed herein. Although specific embodiments are disclosed herein for illustrative purposes, various equivalent modifications are possible without deviating from the present technology, as those of ordinary skill in the relevant art will recognize. In some cases, well-known structures and functions have not been shown and/or described in detail to avoid unnecessarily obscuring the description of the embodiments of the present technology. Although steps of methods may be presented herein in a particular order, in alternative embodiments the steps may have another suitable order. Similarly, certain aspects of the present technology disclosed in the context of particular embodiments can be combined or eliminated in other embodiments. Furthermore, while advantages associated with certain embodiments may have been disclosed in the context of those embodiments, other embodiments can also exhibit such advantages, and not all embodiments need necessarily exhibit such advantages or other advantages disclosed herein to fall within the scope of the present technology. Accordingly, this disclosure and associated technology can encompass other embodiments not expressly shown and/or described herein.

Unless otherwise indicated, all numerical values used in the specification and claims, are to be understood as being modified in all instances by the term "about. " Accordingly, unless indicated to the contrary, the numerical parameters set forth in the following specification and attached claims are approximations that may vary depending upon the desired properties sought to be obtained by the present technology. At the very least, and not as an attempt to limit the application of the doctrine of equivalents to the scope of the claims, each numerical parameter should at least be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Additionally, all ranges disclosed herein are to be understood to encompass any and all subranges subsumed therein. For example, a range of "<NUM> to <NUM>" includes any and all subranges between (and including) the minimum value of <NUM> and the maximum value of <NUM>, i.e., any and all subranges having a minimum value of equal to or greater than <NUM> and a maximum value of equal to or less than <NUM>, e.g., <NUM> to <NUM>.

Claim 1:
A thrombectomy device comprising:
a body (<NUM>) having a plurality of struts (<NUM>) defining a plurality of cells (<NUM>) and forming a mesh, the body (<NUM>) being expandable from a first configuration to a second configuration, the body (<NUM>) having a working length portion (WL) in which the plurality of cells (<NUM>) are configured to penetrate into and/or capture a thrombus when the body (<NUM>) is expanded to the second configuration, and a proximally tapering non-working length portion (NWL) disposed proximal of the working length portion (WL);
one or more electrodes (<NUM>) each coupled to a projection (<NUM>) extending from one of the struts (<NUM>) of the body (<NUM>) within the working length portion (WL);
one or more conductive leads (<NUM>) electrically coupled to the one or more electrodes (<NUM>), the conductive lead(s) (<NUM>) configured to be electrically coupled to a current source (<NUM>),
wherein the electrode(s) (<NUM>) are configured such that, when current is supplied to the conductive lead(s) (<NUM>) via the current source (<NUM>), an electrical charge density is greater in the working length portion (WL) than in the non-working length portion (NWL).