Patent Description:
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.

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

<CIT> discloses a joint assembly for an endovascular device. <CIT> discloses a connection structure. <CIT> discloses a device for intravascular intervention comprising an intervention element, an elongate manipulation member, and a joining element. <CIT> discloses A mechanical locking assembly for an endovascular device. <CIT> discloses a thrombectomy system. <CIT> discloses a method for thrombectomy.

The invention is defined by independent claim <NUM>, with further embodiments defined by the dependent claims.

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 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 interventional element. The positively charged interventional element attracts 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. In some aspects of the present technology, the treatment system includes an elongate manipulation member extending between the current generator and the interventional element. A positive (e.g., delivery) electrode may be integrated into the manipulation member and/or interventional element, and the treatment system further includes a return electrode that may be disposed at a number of different locations. For example, the return electrode can be a wire coupled to the manipulation member. Additionally or alternatively, a return electrode can take the form of a needle, a grounding pad, a conductive element carried by a one or more catheters of the treatment system, a separate guide wire, and/or any other suitable conductive element configured to complete an electrical circuit with the delivery electrode and the 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 core member to the interventional element, through the blood, and to the return electrode, thereby positively charging at least a portion of the interventional element and adhering clot material thereto.

One approach to delivering current to an interventional element is to conduct current along an elongate manipulation member coupled to a proximal end of the interventional element at a connection. The connection can be configured to both mechanically and electrically couple the interventional element and the manipulation member. For example, the manipulation member can comprise a distally located joining element including an aperture extending therethrough. The interventional element can comprise a proximally located attachment portion configured to be inserted into the aperture of the joining element while positioned in a first orientation. The attachment portion can be configured to mechanically interlock with the joining element to prevent and/or limit motion of the interventional element relative to the joining element and to form an electrical connection between the interventional element and the joining element. For example, the attachment portion can be movable between the first orientation and a second orientation in which the attachment portion is mechanically interlocked with the joining element. In some cases, a locking element can be employed to limit motion of the attachment portion with respect to the joining element. The joining element can be electrically coupled to the manipulation member so that current can pass from the manipulation member to the interventional element via the joining element. In some embodiments, the return electrode comprises a core member configured to be positioned within a lumen of the manipulation member and the aperture of the joining element such that a proximal end of the core member extends proximally of the manipulation member and a distal end of the core member extends distally of the joining element. An electrically insulating material can be disposed between at least a portion of the core member and the joining element, the manipulation member, and/or the attachment portion.

Many aspects of the present disclosure 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 104a configured to be coupled to the current generator <NUM> and a distal portion 104b configured to be intravascularly positioned within a blood vessel (such as an intracranial blood vessel). The distal portion 104b can be positioned within the blood vessel at a treatment site at or proximate a thrombus. The treatment device <NUM> includes an interventional element <NUM> at the distal portion 104b, a handle <NUM> at the proximal portion 104a, 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 guide catheter or 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>, a manipulation member <NUM> configured to be slidably disposed within a lumen of the third catheter <NUM>, and a control member <NUM> configured to be disposed within a lumen of the manipulation member <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 manipulation member <NUM> and control member <NUM>. The current generator <NUM> may be coupled to a proximal portion of the manipulation member <NUM>, and/or elsewhere on the proximal portion of the treatment device <NUM>, to deliver electrical current to the interventional element <NUM> and thereby provide an electrically charged environment at the distal portion 104b of the treatment device <NUM>, as described in more detail below. Further, the current generator <NUM> may be coupled to a proximal portion of the control member <NUM> to return electrical current from the electrically charged environment to the current generator <NUM>.

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 blood vessel.

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 blood vessel. 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 guide catheter or balloon guide catheter having an inflatable balloon or other expandable member surrounding the catheter shaft at or near its distal end. 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 blood vessel (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> via the manipulation member <NUM> for delivery to the blood vessel.

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. The current generator <NUM> can include a power source, a first terminal, a second terminal, and a controller. The controller includes a processor coupled to a memory 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 to deliver electric current according to certain parameters provided by the software, code, etc. The power source 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.

In some embodiments, instead of or in addition to a controller, the current generator <NUM> can include drive circuitry. In such embodiments, the current generator <NUM> can include hardwired circuit elements to provide the desired waveform delivery rather than a software-based generator. The drive circuitry can include, for example, analog circuit elements (e.g., resistors, diodes, switches, etc.) that are configured to cause the power source to deliver electric current via the first and second terminals according to the desired parameters. For example, the drive circuitry can be configured to cause the power source to deliver periodic waveforms via the first and second terminals.

The current generator <NUM> may be coupled to a proximal portion of the manipulation member <NUM>, and/or a proximal portion of the third catheter <NUM>, the second catheter <NUM>, and/or first catheter <NUM> to provide an electric current to the interventional element <NUM>. For example, as shown in <FIG>, the current generator <NUM> can be coupled to a proximal portion of the manipulation member <NUM> such that the manipulation member <NUM> functions as a delivery (e.g., positive) electrode or conductive path (i.e., transmitting current from the current generator to the blood vessel and/or treatment site). As shown in <FIG>, the current generator <NUM> can be coupled to a proximal portion of the control member <NUM> such that the control member <NUM> functions as a return (e.g., negative) electrode or conductive path (i.e., transmitting current from the blood vessel and/or treatment site to the current generator <NUM>). In other embodiments, the return electrode can be separate from the control member. For example, the return electrode can be carried by one or more of the third catheter <NUM>, the second catheter <NUM>, and/or first catheter <NUM>. In some embodiments, the return electrode can be provided via one or more external electrodes, such as a needle puncturing the patient, or a grounding pad applied to the patient's skin.

The system can include multiple (e.g., two or more), distinct conductive paths or channels for passing electrical current along the system. The interventional element <NUM> can serve as one electrode (e.g., the positive or delivery electrode) in electrical communication with a conductive path via the manipulation member <NUM>. Another of the conductive paths of the system can be in electrical communication with another electrode (e.g., a negative or return electrode). For example, the control member <NUM> can serve as the negative or return electrode. The various embodiments of the manipulation member <NUM> can be configured to push and pull a device such as the interventional element <NUM> along the bodily lumen.

As noted above, the first terminal of the current generator <NUM> can be connected to a delivery electrode and the second terminal of the current generator <NUM> can be connected to a return electrode. For example, as shown in <FIG>, the manipulation member <NUM> can be connected to a positive terminal of the current generator <NUM> and the control member <NUM> can be connected to a negative terminal of the current generator <NUM>. As shown in <FIG>, the manipulation member <NUM> and the interventional element <NUM> can be joined at a connection <NUM> to secure the interventional element <NUM> relative to the manipulation member <NUM> and to complete an electrical pathway between the elongate manipulation member <NUM> to the interventional element <NUM>. The interventional element <NUM> can be metallic or electrically conductive so that 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 positive terminal of the current generator <NUM>, distally along the manipulation member <NUM> to the interventional element <NUM> and through the surrounding media (e.g., blood, tissue, thrombus, etc.) before returning proximally along the control member <NUM> to the negative terminal of the current generator <NUM>, thereby positively charging at least a portion of the interventional element <NUM> and promoting clot adhesion.

The current generator <NUM> can include a power source and either a processor coupled to a memory that stores instructions for causing the power source to deliver electric current according to certain parameters, or hardwired circuit elements configured to deliver electric current according to the desired parameters. The current generator <NUM> may be integrated into the manipulation member <NUM> and/or control member <NUM> or may be removably coupled to the manipulation member <NUM> and/or control member <NUM>, for example via clips, wires, plugs or other suitable connectors.

In certain embodiments, the polarities of the current generator <NUM> can be switched, so that the negative terminal is electrically coupled to the manipulation member <NUM> and the positive terminal is electrically coupled to the control member <NUM>. This can be advantageous when, for example, attempting to attract predominantly positively charged material to the interventional element <NUM>, or when attempting to break up a clot rather than grasp it with an interventional element <NUM>. In some embodiments alternating current (AC) signals may be used rather than DC. In certain instances, AC signals may advantageously help break apart a thrombus or other material.

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 interventional element <NUM> can have a low-profile, constrained or compressed configuration for intravascular delivery to the blood vessel within the third catheter <NUM>, and an expanded configuration for securing and/or engaging clot material and/or for restoring blood flow in the blood vessel, for example at the treatment site. The interventional element <NUM> has a proximal portion including an attachment portion 106a that may be coupled to the manipulation member <NUM> and a distal portion comprising an open cell framework or body 106b. In some embodiments, the body 106b of the interventional element <NUM> can be generally tubular (e.g., cylindrical), and the proximal portion of the interventional element <NUM> can taper proximally to the attachment portion 106a.

The interventional element <NUM> can be a metallic and/or electrically conductive thrombectomy device. For example, the interventional element can include or be made of stainless steel, nitinol, cobalt-chromium, platinum, tantalum, alloys thereof, or any other suitable material. In some embodiments, the interventional element can have at least an outer surface of a highly conductive metal such as gold or copper; in some such embodiments, the entire interventional element is formed of gold or copper, and in other such embodiments the interventional element is formed from a first metal or alloy such as stainless steel, nitinol, etc. which is completely or partially plated or coated with a second metal or alloy such as gold or copper. 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 mesh structure may include a plurality of struts and open spaces or cells formed by or located between the struts. In some embodiments, the struts and spaces may be situated along the longitudinal direction of the interventional element <NUM>, the radial direction, or both.

The manipulation member <NUM> can be any suitable elongate member configured to advance the interventional element <NUM> to a treatment site within a blood vessel. For example, the manipulation member <NUM> can be or include a wire, tube (e.g., a hypotube), coil, or any combination thereof. According to some embodiments, the manipulation member <NUM> comprises an elongate tubular member defining a lumen therethrough. In some embodiments, the manipulation member <NUM> can comprise a distally located aperture configured to receive the attachment portion of the interventional element. In some embodiments, the manipulation member <NUM> comprises a distally located joining element comprising the aperture configured to receive the attachment portion. The manipulation member <NUM> can have a length sufficient to extend from a location outside the patient's body through the vasculature to a treatment site within the patient's body. The manipulation member <NUM> can be a monolithic structure or formed of multiple joined segments. In some embodiments, the manipulation member <NUM> can comprise a laser-cut hypotube having a spiral cut pattern (or other pattern of cut voids) formed in its sidewall along at least a portion of its length. The manipulation member <NUM> can be metallic and/or electrically conductive to deliver current from the current generator <NUM> to the interventional element <NUM>. For example, the manipulation member <NUM> can comprise or consist of nickel titanium alloy, stainless steel, or other metals or alloys. In embodiments that comprise multiple joined segments, the segments may be of the same or different materials. For example, some or all of the manipulation member <NUM> can be formed of stainless steel, or other suitable materials known to those skilled in the art. Nickel titanium alloy may be preferable for kink resistance and reduction of imaging artifacts.

As described herein, the control member <NUM> can be configured to secure or retain a position of the interventional element <NUM> relative to the manipulation member. Additionally or alternatively, the control member <NUM> can be configured to function as a negative (e.g., return) electrode. The control member <NUM> can be any suitable elongate member configured to extend through a lumen of the manipulation member <NUM>. For example, the control member <NUM> can be or include a wire, tube (e.g., a hypotube), coil, or any combination thereof. The control member <NUM> can have a length sufficient to extend from a location outside the patient's body through the vasculature to a treatment site within the patient's body. The control member <NUM> can be a monolithic structure or formed of multiple joined segments. The control member <NUM> can be metallic or electrically conductive to deliver current from the surrounding media (e.g., blood, tissue, thrombus, etc.) to the current generator <NUM>. For example, the control member <NUM> can comprise or consist of nickel titanium alloy, stainless steel, or other metals or alloys. In embodiments that comprise multiple joined segments, the segments may be of the same or different materials. For example, some or all of the control member <NUM> can be formed of stainless steel, or other suitable materials known to those skilled in the art. Nickel titanium alloy may be preferable for kink resistance and reduction of imaging artifacts. The control member <NUM> can be electrically insulated along some or all of its length. In some embodiments, the control member <NUM> comprises an insulated wire or guide wire having one or more exposed, electrically conductive portions. For example, a distal end portion of the control member <NUM> can be exposed to conduct current from surrounding media (e.g., blood, tissue, thrombus, etc.) at a treatment site. In some such embodiments, the conductive element of the control member <NUM> can have at least an outer surface of a highly conductive metal such as gold or copper, so as to form gold or copper electrodes where insulation is removed or omitted. When implementing this, the entire conductive element of the control member can be formed of gold or copper, or it can be formed from a first metal or alloy such as stainless steel, nitinol, etc. which is completely or partially plated, coated or surrounded (e.g. in the form of a drawn-filled tube) with a second metal or alloy such as gold or copper. This can be done in combination with a gold or copper outer surface of the interventional element <NUM> such that all electrode surfaces are of a single metal or alloy such as gold, or copper, or other desired conductive metal or alloy.

In some embodiments, the treatment device <NUM> can comprise one or more electrically insulating materials. For example, an insulating material can be disposed on one or more portions of the control member <NUM> to electrically isolate the control member <NUM> from the manipulation member <NUM>, the connection <NUM>, and/or the interventional element <NUM>. Additionally or alternatively, an insulating material can be disposed within a lumen of the manipulation member <NUM> to electrically isolate the manipulation member <NUM> from the control member <NUM> and/or the attachment portion of the interventional element <NUM>. In some embodiments, an insulating material is disposed over an outer surface of the manipulation member <NUM> along at least a portion of a length of the manipulation member <NUM> to direct current through the manipulation member <NUM> and prevent and/or limit current loss from the manipulation member <NUM> to the surrounding environment. As shown in <FIG>, in some embodiments, an insulating material <NUM> can be disposed adjacent to a proximal end portion 116a and/or a distal end portion 116b of the manipulation member <NUM>. The insulating material may be disposed along an entire length of the manipulation member <NUM> and/or the control member <NUM> or the insulating material may be disposed along select portions of the manipulation member <NUM> and/or the control member <NUM>. The insulating material may comprise polyimide, parylene, PTFE, or another suitable electrically insulating material.

As shown in <FIG> and <FIG>, the interventional element <NUM> and the manipulation member <NUM> can be coupled at a connection <NUM>. According to some embodiments, the interventional element <NUM> and the manipulation member <NUM> can be substantially permanently attached together at the connection <NUM>. That is, the interventional element <NUM> and the manipulation member <NUM> can be attached together in a manner that, under the expected use conditions of the device, the interventional element <NUM> and the manipulation member <NUM> would not become unintentionally separated from one another. In some embodiments, the treatment device <NUM> can comprise a portion, located proximally or distally of the connection <NUM>, that is configured for selective detachment of the interventional element <NUM> from the manipulation member <NUM>. For example, such a portion can comprise an electrolytically severable segment of the manipulation member <NUM>. In some embodiments, the device can be devoid of any feature that would permit selective detachment of the interventional element <NUM> from the manipulation member <NUM>. As described in more detail elsewhere herein, the connection <NUM> can provide a mechanical interlock between the interventional element <NUM> and the manipulation member <NUM>. Moreover, the connection <NUM> can be configured to complete an electrically conductive path between the interventional element <NUM> and the elongate manipulation member <NUM>.

<FIG> illustrates an enlarged perspective view of the connection <NUM>, according to some embodiments, between the manipulation member <NUM> and the interventional element <NUM>. In some embodiments, for example as shown in <FIG>, the manipulation member <NUM> comprises a distally located joining element <NUM> including an aperture <NUM> configured to receive a proximally located attachment portion 106a of the interventional element and/or at least a portion of the control member <NUM>. As shown in <FIG>, the attachment portion 106a of the interventional element <NUM> is configured to mechanically interlock with a joining element <NUM> to secure the interventional element <NUM> to the manipulation member <NUM>. According to some embodiments, the control member <NUM> can be disposed within the aperture at a radially adjacent position relative to the attachment portion 106a to facilitate such securement. Further, the control member <NUM> may be affixed to the joining element <NUM> via an adhesive.

In some embodiments, the connection <NUM> can comprise a bonding agent in addition or alternative to the joining element <NUM> and/or control member <NUM>. The bonding agent can comprise adhesive, solder, welding flux, brazing filler, etc. In some embodiments, the bonding agent can bond to the connection <NUM> without applying heat. For example, the bonding agent can comprise a UV-curable adhesive. In embodiments that comprise a polymer coating of the wire or polymer tubing, use of a bonding agent that avoids application of heat that would damage the polymer may be preferred.

<FIG> is a plan view of the interventional element <NUM>, depicted in an unfurled or flattened configuration for ease of understanding, and <FIG> are enlarged detail views of the attachment portion 106a of the interventional element <NUM>. As previously described, the interventional element <NUM> has a proximal portion that may be coupled to the manipulation member <NUM> and a distal portion. The interventional element <NUM> has a proximal portion including an attachment portion 106a that may be coupled to the manipulation member <NUM> and a distal portion comprising an open cell framework or body 106b. The attachment portion 106a of the interventional element <NUM> can have a substantially constant thickness, such as would result from the interventional element <NUM> being cut from a tube or sheet of material, for example. In other embodiments, the thickness of the attachment portion 106a can vary across its length, width, or both.

The attachment portion 106a can comprise a retention region <NUM> and one or more engagement features <NUM> (e.g., proximal engagement feature 132a, distal engagement feature 132b). The retention region <NUM> can comprise a projection or arm extending proximally of the body 106b of the interventional element <NUM>. Each of the one or more engagement features <NUM> can comprise a protrusion, flange, bump, ridge, shoulder, barb, or other suitable structural feature. In some embodiments, one or more engagement features <NUM> extend radially or laterally outwardly away from the retention region <NUM> and/or away from a central longitudinal axis L of the device. The attachment portion 106a can comprise any suitable number of engagement features <NUM> at any suitable location with respect to the retention region <NUM>. For example, although <FIG> depict the proximal engagement feature 132a disposed at a proximal terminus of the retention region <NUM>, each of the one or more engagement features <NUM> can be positioned at any suitable location with respect to the retention region <NUM>. In some embodiments, the attachment portion 106a comprises more than one retention region <NUM>.

The retention region <NUM> can optionally be configured to be radially or laterally biased such that the retention region <NUM> maintains a residual spring tension or outward preload or bias when engaged with the joining element <NUM>. This is because the joining element <NUM> can prevent and/or limit the retention region <NUM> from moving laterally outward to the rest or unbiased position that the retention region <NUM> would otherwise occupy. The resulting residual tension can increase the stability of the connection <NUM>.

The proximal engagement feature 132a and/or the distal engagement feature 132b can have a greatest cross-sectional dimension that is larger than a greatest cross-sectional dimension of the retention region <NUM>. In some embodiments, the greatest cross-sectional dimension is a maximum lateral dimension that is measured in a direction perpendicular to a longitudinal axis L, extending in a proximal-distal direction, of the device. Accordingly, as shown in <FIG>, the proximal engagement feature 132a can comprise a distal-facing surface 134a and the distal engagement feature 132b can comprise a proximal-facing surface 134b. The distal-facing surface 134a and/or the proximal-facing surface 134b distal-facing surface can form a shoulder, planar surface, flange, or other suitable engagement surface that is configured to abut or otherwise engage with a corresponding engagement surface of the joining element <NUM>. For example, the distal-facing surface 134a can be positioned to abut a proximal-facing surface (e.g., a proximal end surface) of the joining element <NUM> and the proximal-facing surface 134b can be positioned to abut a distal-facing surface (e.g., a distal end surface) of the joining element <NUM>. In some embodiments, the distal-facing surface 134a and/or the proximal-facing surface 134b extends outwardly (e.g., radially, laterally, and/or circumferentially outwardly) from the retention region <NUM>. In some embodiments, the distal-facing surface 134a and/or the proximal-facing surface 134b forms an oblique angle with the longitudinal axis L of the device, for example being substantially orthogonal to the longitudinal axis L of the device.

<FIG> illustrate an embodiment of the joining element <NUM> in accordance with the present technology. As shown in <FIG>, the joining element <NUM> can comprise a first end surface <NUM>, a second end surface <NUM> opposite the first end surface along a length of the joining element, a sidewall <NUM> therebetween, and an aperture <NUM> extending from the first end surface <NUM> to the second end surface <NUM>. The sidewall <NUM> can be generally annular and/or the first and second end surfaces <NUM>, <NUM> can have a generally circular cross-sectional shape such that the joining element <NUM> has an overall generally cylindrical shape. The joining element <NUM> can comprise a circumferential element such as a band, collar, coil, etc. The joining element <NUM> can be configured to surround all or a portion of the length of the retention region <NUM>. In some embodiments, the joining element <NUM> is circumferentially discontinuous. As shown in <FIG>, the aperture <NUM> can have a first cross-sectional dimension d1 along a first direction A1 that is greater than a second cross-sectional dimension d2 along a second direction A2 orthogonal to the first direction A1. For example, the aperture <NUM> can have a generally oblong cross-sectional shape (e.g., ovular, rectangular, etc.). In some embodiments, the first and second directions A1, A2 are radial or lateral directions.

The joining element <NUM> can be positioned at the distal end portion 116b of the manipulation member <NUM>. As described herein, the joining element <NUM> can be configured to be coupled to the manipulation member <NUM>. In some embodiments, the joining element <NUM> is configured such that the first end surface <NUM> is proximal-facing and the second end surface <NUM> is distal-facing. The first end surface <NUM> can be configured to be coupled to the distal end portion 116b of the manipulation member <NUM>. The joining element <NUM> can be coupled to the manipulation member via welding, adhesive, crimping, insertion, interference fit, or another suitable process or technique. In some embodiments, the joining element <NUM> is electrically coupled to the manipulation member <NUM>. Accordingly, the joining element <NUM> can comprise an electrically conductive material. In some embodiments, the joining element <NUM> is configured to serve as a radiopaque marker and can be formed of a radiopaque material such as, for example, platinum or platinum alloys, including platinum-iridium. Additionally or alternatively, the joining element <NUM> can comprise a material such steel or steel alloys, including stainless steel, or aluminum or aluminum alloys. In some embodiments, the joining element <NUM> and manipulation member <NUM> comprise a monolithic structure.

The joining element <NUM> can have a greatest radial dimension (e.g., an outer diameter) that is substantially similar to a greatest radial dimension (e.g., an outer diameter) of the manipulation member <NUM>. In some embodiments, the first cross-sectional dimension d1 and/or the second cross-sectional dimension d2 of the aperture <NUM> of the joining element <NUM> are less than a cross-sectional dimension of the lumen 116c of the manipulation member <NUM> such that, when the joining element <NUM> is coupled to the manipulation member <NUM>, the first end surface <NUM> of the joining element <NUM> obstructs a portion of the lumen 116c of the manipulation member <NUM> and provides an engagement surface for the attachment portion 106a of the interventional element <NUM> to engage with.

The retention region <NUM> of the attachment portion 106a of the interventional element <NUM> can have a greatest cross-sectional dimension that is less than a smallest cross-sectional dimension of the aperture (e.g., the second cross-sectional dimension d2). The proximal engagement feature 132a and/or the distal engagement feature 132b can have a greatest cross-sectional dimension that is less than the first cross-sectional dimension d1 of the aperture <NUM> and greater than the second cross-sectional dimension d2 of the aperture <NUM>. Accordingly, as shown in <FIG>, the attachment portion 106a can be configured to be inserted into the aperture of the joining element <NUM> when the attachment portion 106a is positioned in a first orientation in which the greatest cross-sectional dimension of the proximal engagement feature 132a and/or the distal engagement feature 132b is aligned with the first cross-sectional dimension d1 of the aperture <NUM>. In such embodiments, the attachment portion 106a may be slidably passed into the aperture <NUM> such that the retention region <NUM> is positioned at least partially within the aperture <NUM> and the proximal engagement feature 132a is positioned proximal of the joining element <NUM> within the lumen 116c of the manipulation member <NUM> (again, as depicted in <FIG>).

To mechanically interlock the attachment portion 106a of the interventional element <NUM> with the joining element <NUM>, the attachment portion 106a can be moved from the first orientation to a second orientation (see <FIG>). For example, the attachment portion 106a can be rotated in a circumferential direction approximately about the longitudinal axis of the manipulation member <NUM>, such that the greatest cross-sectional dimension of the proximal engagement feature 132a and/or the distal engagement feature 132b is aligned with the second (smaller) cross-sectional dimension d2 of the aperture <NUM>. In embodiments in which the greatest cross-sectional dimension of the proximal engagement feature 132a is greater than the second cross-sectional dimension d2 of the aperture <NUM>, for example as shown in <FIG>, the proximal engagement feature 132a can be configured to engage the first end surface <NUM> of the joining element <NUM>. Similarly, in embodiments in which the greatest cross-sectional dimension of the distal engagement feature 132b is greater than the second cross-sectional dimension d2 of the aperture <NUM>, for example as shown in <FIG>, the distal engagement feature 132b can be configured to engage the second end surface <NUM> of the joining element <NUM>. Additionally or alternatively, the proximal engagement feature 132a and/or the distal engagement feature 132b may be configured to engage the aperture <NUM> of the joining element <NUM>. The proximal engagement feature 132a may be configured to avoid contact with a wall of the lumen 116c of the manipulation member <NUM> or to contact a wall of the lumen 116c of the manipulation member <NUM>. The engagement features <NUM> can be configured to prevent and/or limit motion (e.g., longitudinal movement) of the interventional element <NUM> relative to the joining element <NUM> and thereby the manipulation member <NUM>. For example, as shown in <FIG>, the proximal engagement feature 132a can be configured to abut the first end surface <NUM> (i.e., the proximal-facing surface) of the joining element <NUM> when the retention region <NUM> is positioned within the aperture <NUM> to thereby prevent and/or limit distal translation of the interventional element <NUM> with respect to the joining element <NUM>. Similarly, the distal engagement feature 132b can be configured to abut the second end surface <NUM> (i.e., the distal-facing surface) of the joining element <NUM> when the retention region <NUM> is positioned within the aperture <NUM> to thereby prevent and/or limit proximal translation of the interventional element <NUM> with respect to the joining element <NUM>. Additionally or alternatively, each of the engagement features <NUM> can be configured to prevent and/or limit distal translation, proximal translation, and/or rotation of the interventional element <NUM> with respect to the joining element <NUM>. In addition to securing the interventional element <NUM> to the manipulation member <NUM>, the mechanical interlock and contact between the attachment portion 106a and the joining element <NUM> is configured to electrically couple the attachment portion 106a to the joining element <NUM> such that current supplied to the manipulation member <NUM> may pass to the interventional element <NUM> via the joining element <NUM>.

In some embodiments, a control member (e.g., control member <NUM> as shown in <FIG>) can be inserted through the aperture <NUM> after the attachment portion 106a of the interventional element <NUM> has been moved to the second orientation. For example, the attachment portion 106a can be rotated with respect to the joining element <NUM> (as shown in <FIG>), and then an elongate control member can be slidably inserted through the aperture <NUM> at a position radially adjacent the attachment portion 106a. By occupying this space within the aperture, the control member can inhibit the attachment portion 106a from reverting to the first orientation (e.g., precluding the attachment portion 106a from rotating with respect to the joining element <NUM>). As noted previously, in some embodiments the control member can also serve as a negative (e.g., return) electrode, for example taking the form of an elongated wire that is insulated along at least a portion of its length, with one or more exposed portions of the wire that are configured to contact electrolytic media, such as blood, while positioned at the treatment site. In some embodiments, a bonding agent (e.g., weld, adhesive, solder, etc.) can be applied to some or all of the control member, joining element <NUM>, and/or attachment portion 106a after they have been moved into position such that the joining element <NUM>, attachment portion 106a, and control member are substantially permanently connected. In some embodiments, the control member <NUM> may be omitted from the aperture <NUM>, and a filler material such as solder, adhesive, epoxy, etc., or some other element, may be placed in the portion(s) of the aperture <NUM> not occupied by the retention region <NUM> in order to prevent the retention region <NUM> from exiting the aperture <NUM>.

According to some embodiments, for example as shown in <FIG>, a manipulation member <NUM> is comprises an aperture <NUM> configured to receive an attachment portion 606a of an interventional element <NUM>. The aperture <NUM> may be positioned at or near a distal end portion 616b of the manipulation member <NUM>. In such embodiments, the manipulation member <NUM> may not comprise a distally located joining element. As described herein, the attachment portion 606a can comprise a retention region <NUM> and an engagement feature <NUM>. In some embodiments, the attachment portion 606a is configured to be slidably inserted into the aperture <NUM> along a first direction. Once inserted, the engagement feature <NUM> can be configured to engage with the manipulation member <NUM> such the attachment portion 606a and the manipulation member <NUM> are mechanically interlocked. The mechanical interlock between attachment portion 606a and the manipulation member <NUM> can be configured to limit motion of the interventional element <NUM> with respect to the manipulation member <NUM> along a second direction. For example, the attachment portion 606a can be configured to be inserted into the aperture <NUM> along a radial dimension of the manipulation member <NUM> such that motion of the interventional element <NUM> is limited with respect to the manipulation member <NUM> along a longitudinal axis of the manipulation member <NUM> (e.g., in a proximal direction or in a distal direction). In some embodiments, the second direction can be the same as the first direction. Additionally or alternatively, the attachment portion 606a can be configured to be rotated in a radial direction once inserted into the aperture <NUM> to engage the manipulation member <NUM>, as described herein. As with the embodiments described previously with respect to <FIG>, an elongated control member (e.g., control member <NUM>) can be slidably inserted through the lumen of the manipulation member <NUM> and configured to retain the attachment portion 606a of the interventional element <NUM> in place with respect to the manipulation member <NUM>.

<FIG> illustrate a joining element <NUM> configured in accordance with several embodiments of the present technology. In some embodiments, the joining element <NUM> can be similar to any of the embodiments of the joining element <NUM> disclosed herein, except as further described. As with the embodiments described previously with respect to <FIG>, the joining element <NUM> can be configured to be positioned at and/or coupled to a distal end portion of a manipulation member (e.g., distal end portion 116b of manipulation member <NUM>) and can be configured to retain an attachment portion of an interventional element (e.g., attachment portion 106a of interventional element <NUM>) in place with respect to the manipulation member. As shown in <FIG>, the joining element <NUM> can comprise a first end surface <NUM>, a second end surface <NUM> opposite the first end surface along a length of the joining element, a sidewall <NUM> therebetween, and an aperture <NUM> extending from the first end surface <NUM> to the second end surface <NUM>. The sidewall <NUM> can be generally annular and/or the first and second end surfaces <NUM>, <NUM> can have a generally circular cross-sectional shape such that the joining element <NUM> has an overall generally cylindrical shape. The joining element <NUM> can comprise a circumferential element such as a band, collar, coil, etc. The joining element <NUM> can be configured to surround all or a portion of the length of a retention region of an attachment portion of an interventional element (e.g., retention region <NUM>). In some embodiments, the joining element <NUM> is circumferentially discontinuous. The joining element <NUM> can comprise a radiopaque material such as, for example, platinum or platinum alloys, including platinum-iridium. Additionally or alternatively, the joining element <NUM> can comprise a material such steel or steel alloys, including stainless steel, or aluminum or aluminum alloys, or titanium, or nickel-titanium alloy such as nitinol.

The aperture <NUM> can comprise a first portion 730a with a first cross-sectional shape and a second portion 730b with a second cross-sectional shape. For example, as shown in <FIG> the first portion 730a can have a generally circular first cross-sectional shape and the second portion 730b can have a generally rectangular second cross-sectional shape. The first and second cross-sectional shapes can be different from one another in shape (e.g., as shown in <FIG>, etc.) or similar to one another in shape (e.g., both the first and second cross-sectional shapes can be generally rectangular, etc.).

The aperture <NUM> can have a first cross-sectional dimension d1 along a first direction A1 and a second cross-sectional dimension d2 along a second direction A2 orthogonal to the first direction A1. In some embodiments, the first and second directions A1, A2 are radial or lateral directions. In some embodiments, the second cross-sectional dimension d2 varies along the second direction A2. For example, as shown in <FIG>, the second cross-sectional dimension d2 can be greater at the first portion 730a of the aperture <NUM> than the second cross-sectional dimension d2 at the second portion 730b of the aperture <NUM>. In some embodiments, the first cross-sectional dimension d1 is greater than the second cross-sectional dimension d2 at one or more locations along the first direction A1.

In some embodiments, the aperture <NUM> of the joining element <NUM> can be configured to receive a locking element therein to facilitate mechanical interlocking of the joining element <NUM> with an attachment portion of an interventional element. <FIG> illustrate a locking element <NUM> configured in accordance with several embodiments of the present technology. The locking element <NUM> can comprise a first end surface <NUM>, a second end surface <NUM> opposite the first end surface <NUM> along a length of the locking element <NUM>, a sidewall <NUM> therebetween, and an aperture <NUM> extending from the first end surface <NUM> to the second end surface <NUM>. As described in greater detail herein, in some embodiments the sidewall <NUM> is generally annular.

The locking element <NUM> can comprise a radiopaque material such as, for example, platinum or platinum alloys, including platinum-iridium. Additionally or alternatively, the locking element <NUM> can comprise a material such as steel or steel alloys, including stainless steel, or aluminum or aluminum alloys, or titanium, or nickel-titanium alloy such as nitinol. In some embodiments, the locking element <NUM> comprises a polymeric material or a ceramic material. The locking element <NUM> can comprise a mesh, a wire, a coil, or another suitable structure configured to inhibit motion of the attachment portion with respect to the joining element.

<FIG> depict the locking element <NUM> assembled with the joining element <NUM>. As shown in <FIG>, the locking element <NUM> can be configured to be inserted into the aperture <NUM> of the joining element <NUM>. The locking element <NUM> and the aperture <NUM> can be sized such that there is an interference fit, a transition fit, or a clearance fit (see <FIG>) between the locking element <NUM> and the joining element <NUM>. In some embodiments, the locking element <NUM> has a cross-sectional shape generally corresponding to a cross-sectional shape of at least a portion of the aperture <NUM> of the joining element <NUM>. In some embodiments, the locking element <NUM> is configured to be positioned within the first portion 730a of the aperture <NUM> of the joining element <NUM> and the locking element <NUM> has a cross-sectional shape generally corresponding to the cross-sectional shape of the first portion 730a of the aperture <NUM> of the joining element <NUM>. For example, as shown in <FIG>, the locking element <NUM> can have a generally circular cross-sectional shape (e.g., the sidewall <NUM> is generally annular) corresponding to the generally circular cross-sectional shape of the first portion 730a of the aperture <NUM>. The locking element <NUM> can be configured to be positioned within the aperture <NUM> such that the first end surface <NUM> of the locking element <NUM> is generally flush with the first end surface <NUM> of the joining element <NUM> and/or the second end surface <NUM> of the locking element <NUM> is generally flush with the second end surface <NUM> of the joining element <NUM>. In some embodiments, a length of the locking element <NUM> is the same as a length of the joining element <NUM>.

<FIG> illustrates an interventional element <NUM>, a joining element <NUM>, and a locking element <NUM> assembled in accordance with several embodiments of the present technology. <FIG> illustrate a connection <NUM> between a manipulation member <NUM> and the assembled interventional element <NUM>, joining element <NUM>, and locking element <NUM>. <FIG> illustrates the connection <NUM> with an elongate control member <NUM> inserted through the locking element <NUM>. In some embodiments, the manipulation member <NUM> can be similar to any of the embodiments of the manipulation member disclosed herein (e.g., manipulation member <NUM>), except as further described, and the control member <NUM> can be similar to any of the embodiments of the control member disclosed herein (e.g., control member <NUM>), except as further described. The assembled interventional element <NUM>, joining element <NUM>, and locking element <NUM> can be secured to a distal end portion 1016b of the manipulation member <NUM>. In some embodiments, the interventional element <NUM> can be similar to any of the embodiments of the interventional element disclosed herein (e.g., interventional element <NUM>), except as further described. For example, the interventional element <NUM> can include an attachment portion 1006a comprising a retention region <NUM>, a proximal engagement feature 1032a and a distal engagement feature 1032b. In some embodiments, the joining element <NUM> can be similar to any of the embodiments of the joining element disclosed herein (e.g., joining element <NUM>, joining element <NUM>, etc.). For example, the joining element <NUM> can have an aperture <NUM> extending therethrough. The aperture <NUM> can have a first portion 1030a with a first cross-sectional shape and a second portion 1030b with a second cross-sectional shape. As described herein, the aperture <NUM> can have a second dimension (e.g., second dimension d2) along a second direction (e.g., second direction A2) that is greater at the first portion 1030a of the aperture <NUM> than the second dimension at the second portion 1030b of the aperture <NUM>. In some embodiments, the locking element <NUM> can be similar to any of the embodiments of the locking element disclosed herein (e.g., locking element <NUM>).

To secure the interventional element <NUM> to the manipulation member <NUM>, the retention region <NUM> of the attachment portion 1060a can be inserted into the aperture <NUM> of the joining element <NUM>. As previously described with reference to <FIG>, the retention region <NUM> can have a greatest cross-sectional dimension that is no greater than a smallest cross-sectional dimension of the aperture <NUM> of the joining element <NUM>. The proximal engagement feature 1032a and/or the distal engagement feature 1032b can have a greatest cross-sectional dimension that is less than the first cross-sectional dimension of the aperture <NUM> along a first direction (e.g., first direction A1) and greater than the second cross-sectional dimension of the aperture along a second direction (e.g., second direction A2) in at least one location (e.g., at the second portion 1030b of the aperture <NUM>).

In some embodiments, the proximal engagement feature 1032a and the distal engagement feature 1032b each have a greatest cross-sectional dimension that is less than the second cross-sectional dimension at the first portion 1030a of the aperture <NUM>. In such embodiments, the attachment portion 1006a can be configured to be inserted into the first portion 1030a of the aperture <NUM> when the attachment portion 1006a is positioned such that the greatest cross-sectional dimension of the proximal engagement feature 1032a and/or the distal engagement feature 1032b is generally aligned with the second cross-sectional dimension of the aperture <NUM>. The attachment portion 1006a may be slidably passed into the first portion 1030a of the aperture <NUM> such that the retention region <NUM> is positioned at least partially within the first portion 1030a of the aperture <NUM> and the proximal engagement feature 1032a is positioned proximal of the joining element <NUM>. To mechanically interlock the attachment portion 1006a with the joining element <NUM>, the attachment portion 1006a can be radially displaced within the aperture <NUM> until the retention region <NUM> is positioned at least partially within the second portion 1030b of the aperture <NUM>. In such a configuration, the proximal engagement feature 1032a can engage a first end surface <NUM> of the joining element <NUM> and/or the distal engagement feature 1032b can engage a second end surface <NUM> of the joining element <NUM>. Additionally or alternatively, the proximal engagement feature 1032a and/or the distal engagement feature 1032b may be configured to engage the aperture <NUM> of the joining element <NUM>.

In some embodiments, the attachment portion 1006a can be positioned such that the greatest cross-sectional dimension of the proximal engagement feature 1032a and/or the distal engagement feature 1032b is generally aligned with the first (e.g., larger) cross-sectional dimension of the aperture <NUM>. In such an orientation relative to the aperture <NUM>, the attachment portion 1006a may be slidably passed into the aperture <NUM> such that the retention region <NUM> is positioned at least partially within the aperture <NUM> and the proximal engagement feature 1032a is positioned proximal of the joining element <NUM>. As previously described with reference to <FIG>, the attachment portion 1006a can then be rotated in a circumferential direction approximately about the longitudinal axis of the joining element <NUM> such that the greatest cross-sectional dimension of the proximal engagement feature 1032a and/or the distal engagement feature 1032b is aligned with the second (e.g., smaller) cross-sectional dimension of the aperture <NUM>. Additionally or alternatively, the attachment portion 1006a can be radially displaced within the aperture <NUM> to position the attachment portion 1006a in a desired portion of the aperture <NUM> (e.g., the second portion 1030b as described above).

The engagement features 1032a, 1032b can be configured to prevent and/or limit motion (e.g., longitudinal movement) of the interventional element <NUM> relative to the joining element <NUM> and thereby the manipulation member <NUM>. For example, as shown in <FIG>, the proximal engagement feature 1032a can be configured to abut the first end surface <NUM> (i.e., the proximal-facing surface) of the joining element <NUM> when the retention region <NUM> is positioned within the aperture <NUM> to prevent distal translation of the interventional element <NUM> with respect to the joining element <NUM>. Similarly, the distal engagement feature 1032b can be configured to abut the second end surface <NUM> (i.e., the distal-facing surface) of the joining element <NUM> when the retention region <NUM> is positioned within the aperture <NUM> to prevent proximal translation of the interventional element <NUM> with respect to the joining element <NUM>. Each of the engagement features <NUM> can be configured to prevent distal translation, proximal translation, and/or rotation of the interventional element <NUM> with respect to the joining element <NUM>. In addition to securing the interventional element <NUM> to the manipulation member <NUM>, the mechanical interlock and contact between the attachment portion 1006a and the joining element <NUM> can be configured to electrically couple the attachment portion 1006a to the joining element <NUM> such that current supplied to the manipulation member <NUM> may pass to the interventional element <NUM> via the joining element <NUM>.

As shown in <FIG>, the locking element <NUM> can be inserted into the aperture <NUM> of the joining element <NUM>. For example, the locking element <NUM> can be slidably inserted into the aperture <NUM> of the joining element <NUM>. In some embodiments, the locking element <NUM> is configured to be inserted into the aperture <NUM> of the joining element <NUM> after the attachment portion 1006a has been inserted into the aperture <NUM> of the joining element <NUM>. The locking element <NUM> can be inserted into the aperture <NUM> of the joining element <NUM> at a position that is radially adjacent to the attachment portion 1006a. For example, as shown in <FIG>, the locking element <NUM> can be inserted into the first portion 1030a of the aperture <NUM> of the joining element <NUM> so that the locking element <NUM> is radially adjacent to the attachment portion 1006a. As described herein with reference to <FIG>, the locking element <NUM> and the portion of the aperture <NUM> of the joining element <NUM> configured to receive the locking element <NUM> can be sized so that there is an interference fit, a transition fit, or a clearance fit between the locking element <NUM> and the joining element <NUM>. In various embodiments, the connection <NUM> can comprise a bonding agent in addition or alternative to the joining element <NUM>, the locking element <NUM>, and/or a control member. The bonding agent can comprise adhesive, solder, welding flux, brazing filler, etc. In some embodiments, the bonding agent can bond to the connection <NUM> without applying heat. For example, the bonding agent can comprise a UV-curable adhesive. In embodiments that comprise a polymer coating of the wire or employ polymer tubing as the locking element <NUM>, use of a bonding agent that avoids application of heat that would damage the polymer may be preferred.

The locking element <NUM> can be configured to prevent and/or limit motion of the attachment portion 1006a with respect to the joining element <NUM>. In some embodiments, the locking element <NUM> can be configured to prevent and/or limit radial translation and/or rotation of the attachment portion 1006a with respect to the joining element <NUM>. Such constraint of the attachment portion 1006a can prevent the attachment portion 1006a from reverting to a position and/or orientation in which the attachment portion 1006a can slidably pass through the aperture <NUM> of the joining element <NUM> and/or move proximally and/or distally relative to the joining element <NUM>.

In some embodiments, the joining element <NUM> is configured to be secured to the manipulation member <NUM> once the joining element <NUM>, the locking element <NUM>, and the interventional element <NUM> have been assembled. As described herein, the joining element <NUM> can be secured to the manipulation member <NUM> via welding, adhesive, helical threaded engagement, interference fit or another suitable process. As the proximal engagement feature 1032a can be positioned proximal of the joining element <NUM> in the assembled configuration, the proximal engagement feature 1032a can be positioned within a lumen 1016c of the manipulation member <NUM> once the joining element <NUM> is secured to the manipulation member <NUM>. The proximal engagement feature 1032a may be configured to avoid contact with a wall of the lumen 1016c of the manipulation member <NUM> or to contact the wall of the lumen 1016c of the manipulation member <NUM>. In some embodiments, the joining element <NUM> is configured to be secured to the manipulation member <NUM> prior to assembly of the joining element <NUM> with the locking element <NUM> and/or the interventional element <NUM>.

In some embodiments, for example as shown in <FIG>, the control member <NUM> can be inserted through the aperture <NUM> of the locking element <NUM>. The elongate control member <NUM> can be slidably inserted through the aperture <NUM> of the locking element <NUM>. As noted previously, in some embodiments the control member <NUM> can also serve as a negative (e.g., return) electrode, or as a second electrode, for example taking the form of an elongated wire that is insulated along at least a portion of its length, with one or more exposed portions of the wire that are configured to electrically contact electrolytic media, such as blood, thrombus, saline, etc. while positioned at the treatment site. In such embodiments the interventional element <NUM> can take the form of a positive (e.g., delivery) electrode, or as a first electrode, with one or more exposed portions that are configured to electrically contact electrolytic media such as thrombus, blood, saline, etc..

In some embodiments, a bonding agent (e.g., weld, adhesive, solder, etc.) can be applied to some or all of the control member <NUM>, the locking element <NUM>, the joining element <NUM>, and/or the attachment portion 1006a before, during, or after assembly of the connection <NUM>. In some embodiments, the control member <NUM> may be omitted from the aperture <NUM> of the locking element <NUM>, and a filler material such as solder, adhesive, epoxy, etc., or some other element, may be placed in the aperture <NUM>.

Although many of the embodiments are described above with respect to systems, devices, and methods for electrically enhanced retrieval of material from vessel lumens, the technology is applicable to other applications and/or other approaches, such as mechanical thrombectomy. Moreover, other embodiments in addition to those described herein are within the scope of the technology. Additionally, several other embodiments of the technology can have different configurations, components, or procedures than those described herein. A person of ordinary skill in the art, therefore, will accordingly understand that the technology can have other embodiments with additional elements, or the technology can have other embodiments without several of the features shown and described above with reference to <FIG>.

The descriptions of embodiments of the technology are not intended to be exhaustive or to limit the technology to the precise form disclosed above. Where the context permits, singular or plural terms may also include the plural or singular term, respectively. Although specific embodiments of, and examples for, the technology are described above for illustrative purposes, various equivalent modifications are possible within the scope of the technology, as those skilled in the relevant art will recognize. For example, while steps are presented in a given order, alternative embodiments may perform steps in a different order. The various embodiments described herein may also be combined to provide further embodiments.

Claim 1:
A medical device comprising:
a manipulation assembly having a distal portion configured to be intravascularly positioned within a blood vessel lumen, the manipulation assembly comprising:
an elongate tubular member, the tubular member having a proximal portion, a distal portion, and a lumen extending therein; and
a joining element (<NUM>,<NUM>,<NUM>) located at the distal portion of the elongate tubular member, the joining element (<NUM>,<NUM>,<NUM>) having a proximal-end surface (<NUM>,<NUM>,<NUM>), a distal end surface (<NUM>,<NUM>,<NUM>) opposite the proximal end surface (<NUM>,<NUM>,<NUM>), and a lumen extending from the proximal end surface (<NUM>,<NUM>,<NUM>) to the distal end surface (<NUM>,<NUM>,<NUM>) of the joining element (<NUM>,<NUM>,<NUM>); and
an interventional element (<NUM>,<NUM>,<NUM>) comprising a proximally located attachment portion having a distal engagement feature (132b, 1032b) comprising a proximal-facing surface (134b), a proximal engagement feature (132a, 1032a) comprising a distal-facing surface (134a), and a retention region (<NUM>,<NUM>) therebetween, wherein the distal and proximal engagement features (132a,1032a,132b,1032b) each protrude outwardly with respect to the retention region (<NUM>,<NUM>),
characterized in that
the retention region (<NUM>,<NUM>) is positioned within the lumen of the joining element (<NUM>,<NUM>,<NUM>) such that the distal-facing surface (134a) of the proximal engagement feature (132a, 1032a) is positioned to abut the proximal end surface (<NUM>,<NUM>,<NUM>) of the joining element (<NUM>,<NUM>,<NUM>) and thereby limit distal translation of the interventional element (<NUM>,<NUM>,<NUM>) relative to the joining element (<NUM>,<NUM>,<NUM>) and the proximal-facing surface (134b) of the distal engagement feature (132b, 1032b) is positioned to abut the distal end surface (<NUM>,<NUM>,<NUM>) of the joining element (<NUM>,<NUM>,<NUM>) and thereby limit proximal translation of the interventional element (<NUM>,<NUM>,<NUM>) relative to the joining element (<NUM>,<NUM>,<NUM>).