Patent Application
20240156459
Delivery of implantable intravascular therapeutic devices to occlude or treat target sites throughout the body has become an increasingly popular and less invasive method of therapy. For example, implantable therapeutic devices have been used to control vascular bleeding, to occlude the blood supply to tumors, to occlude fallopian tubes, and to occlude vascular aneurysms (e.g., intracranial aneurysms). Some implantable occlusion devices include microcoils, expandable mesh devices, filters, stents, and similar devices that can be delivered to a target site and released by a delivery system. A detachment mechanism may be used to separate the treatment device or occlusion device from the delivery system at the target site.
An implant delivery system is described having a first detachment mechanism and a second detachment mechanism. Either the first detachment system or the second detachment system, or both, can be used to detach and release an implant.
In some examples, the first detachment mechanism is a primary detachment mechanism that is configured and intended to be activated first, while the second detachment mechanism is a secondary detachment mechanism that is intended to be activated second if the first detachment system fails to detach the implant. Alternatively, either the first detachment mechanism or the second detachment mechanism may be configured and intended to be used first. In another alternative, the first detachment mechanism and second detachment mechanism may be used simultaneously.
Put another way, in some examples the delivery system comprises a first detachment mechanism having a first attached configuration where the implant is releasably secured to the elongated pusher, and having a first detached configuration where the implant is released from the elongated pusher; and a second detachment mechanism having a second attached configuration where the implant is releasably secured to the elongated pusher, and having a second detached configuration where the implant is released from the elongated pusher.
In one example, any of the detachment mechanisms may comprise a thermal detachment mechanism, a mechanical detachment mechanism, an electrolytic detachment mechanism, or a thermal-mechanical detachment mechanism.
One of the detachment mechanisms may be configured to mechanically break a heat-severable tether. The primary detachment mechanism may be a thermal detachment mechanism to separate or break a heat-severable tether. The secondary detachment mechanism may be a mechanical detachment mechanism and may further include a fixed member (e.g., a disc) and a movable member (e.g., a disc) within a pusher of the detachment system. Both members may include a passage longitudinally positioned therethrough and which the heat-severable tether is positioned through. The pusher further comprises a fixed sharpened edge positioned between the two members. When the movable member is in a first position, its position and the position of the passages in both members are such that the heat-severable tether does not contact the sharpened edge and thereby remains unbroken. However, when the movable member is longitudinally or axially moved within the pusher (e.g., via a control wire), the angle or position of the heat-severable tether is changed such that it contacts the sharpened edge, thereby breaking tether. Hence, if the heater of the primary detachment mechanism fails to activate or upon activation fails to fully separate the implant from the delivery device, the heat-severable tether can be mechanically moved against the sharpened edge and broken via the secondary detachment mechanism.
Also described is a method for detaching an implant. The method comprises advancing an implant out of a catheter to a target delivery site or area where the occlusion device is attached to a distal end of a pusher via a detachment system. Next, a primary detachment mechanism is activated or actuated to attempt detachment and release of the implant. If the primary detachment system fails to cause complete detachment of the occlusion implant, a secondary detachment system is activated or actuated to cause detachment and fully release of the implant. Activating or actuating the primary detachment mechanism may further include activating or actuating a heater in proximity to a heat-severable tether. Activating or actuating the secondary detachment mechanism may further include mechanically positioning the heat-severable tether against a sharpened edge within the pusher so as to break the heat-severable tether.
Also described is a detachment system for a medical implant with a single, mechanical detachment mechanism. Specifically, the detachment system may solely include the “secondary” detachment mechanism described above, including the tether, fixed member, movable member, and sharpened edge. In another example, the detachment system may include two detachment mechanisms, both of which are mechanical (as described herein), both of which are thermal (as described herein), both of which are electrolytic (as described herein), or both of which are thermal-mechanical (as described herein).
These and other aspects, features and advantages of which embodiments of the invention are capable of will be apparent and elucidated from the following description of embodiments of the present invention, reference being made to the accompanying drawings, in which:
Specific embodiments of the invention will now be described with reference to the accompanying drawings. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of the embodiments illustrated in the accompanying drawings is not intended to be limiting of the invention. In the drawings, like numbers refer to like elements. While different embodiments are described, features of each embodiment can be used interchangeably with other described embodiments. In other words, any of the features of each of the embodiments can be mixed and matched with each other, and embodiments should not necessarily be rigidly interpreted to only include the features shown or described.
The terms distal and proximal are used within this specification. Unless defined otherwise, distal and proximal are used in reference to the physician during a procedure. Hence, proximal tends to be closer to the physician while distal tends to be closer to a target location within a patient. However, this terminology is applicable whether the device is inside or outside of a patient.
This specification is generally directed to a detachment system for medical implants or devices. These implants specifically include microcoils, expandable occlusion devices (e.g., expandable mesh occlusion devices), filters, stents, and similar devices that can be delivered to a target site and released by a delivery system. However, use with other types of implants may also be possible.
These delivery systems may include an elongated pusher that is attached at its distal end to the occlusion device via a detachment mechanism. The detachment mechanism allows the physician to detach the occlusion device once it has been deployed into the patient at a desired location. In the case of aneurysm or other vascular malformation, the occlusion device restricts or blocks the flow of blood, eventually causing thrombosis and tissue growth tissue growth.
Several different types of detachment mechanisms may be used to retain and release occlusion devices. For example, mechanical detachment mechanisms, electrolytic detachment mechanisms, thermal detachment mechanisms, and thermal-mechanical detachment mechanisms can be used to deploy occlusion devices and other medical treatments. Some of these detachment mechanisms may include some drawbacks or possible points of detachment failure. If detachment fails to occur, procedural complications can result if there is not an alternative way to detach the implant (e.g., restraints on cross-sectional space and volume may prohibit the operator from inserting a second detachment device into the delivery system). In one example of a procedural complication, the operator (e.g., physician) may attempt to retract the implant into the delivery device, thereby dislodging the implant from the target site, increasing procedure time if the device is later redeployed, or resulting in a procedure failure if the device cannot be redeployed. Dislodging the implant may also result in damage to surrounding tissue. In another example, after a detachment failure, the operator may retract the implant into the delivery device and further retract the implant proximally to remove it from the delivery system, then later attempt to deploy and detach a second implant at the target site, thereby increasing overall procedure time.
A detachment system may utilize a mechanical grasping mechanism at the end of a pusher that engages a ball shape on the end of a microcoil. The grasping mechanism requires relatively exact sizing and tolerances, otherwise the ball shape may be allowed to slip out of the grasping mechanism and premature detachment may occur, or if oversized, the ball shape may not slip out of the grasping mechanism when detachment is attempted. Mechanical grasping mechanisms may rely on a pull wire that disengages the grasping mechanism from the ball. The pull wire may be difficult to actuate if it is tightly wedged against the ball shape or grasping mechanism, especially if the pusher is positioned in a curved region of a vessel.
A detachment system may utilize electrolytic detachment, which involves conducting electrical current through a patient's blood to an attachment wire of the microcoil, causing corrosion of the attachment wire. The attachment wire eventually severs and detaches the microcoil to deploy it to the target site. However, when an aneurysm site is filled with a relatively large mass of one or more microcoils, less blood is available at the site to conduct current and corrode the attachment wire, thereby making the electrolytic detachment of the microcoil difficult to achieve in some instances, and possibly resulting in detachment failure.
A thermal detachment mechanism may rely on a tether positioned in proximity to a heater. When activated, the heater melts or breaks the tether to release the microcoil. These thermal detachment systems also may rely on an electrical circuit within the delivery device (e.g., within a pusher) to supply electrical current to the heater. Typically, pushers have a relatively small diameter, a relatively long length, and are subject to significant bending as they are advanced through vessels of a patient to a target site. This may result in an interruption of (or disruption within) the electrical circuit or breakage of the electrical circuit during delivery, thereby preventing the heater from being activated by a physician.
An implant detachment system that can recover or otherwise detach its implant after a detachment system's primary detachment mechanism has failed or otherwise encountered difficulty detaching may avoid or minimize procedural complications and procedural failures, for example, by allowing the operator to fully detach the implant from the delivery system without dislodging the implant from the target site, without inserting additional components into the delivery system, and/or without retracting the implant into the delivery device.
A detachment system for an implant is described having a first detachment mechanism and a second detachment mechanism. Either the first detachment mechanism or the second detachment mechanism may be activated or actuated or activated to cause the release of an attached implant. While two detachment mechanisms are primarily described in this specification, embodiments with three, four, or even more of the detachment mechanisms described herein are also possible.
There may be several reasons that two detachment mechanisms may be helpful to a physician during a delivery procedure. For example, one of the detachment mechanisms may fail to detach the implant after the physician has attempted to activate or actuate it. Hence, the other detachment mechanism may provide a backup detachment mechanism that may then release the implant. In another example, the location and/or vessel path to a target location may render one of the detachment mechanisms less desirable (e.g., providing unwanted heat to a sensitive area of a vessel or a particularly tortuous vessel path that may impinge on laterally moveable control wires).
The first and second detachment mechanisms can be any combinations of mechanical detachment mechanisms, electrolytic detachment mechanisms, thermal detachment mechanisms, and thermal-mechanical detachment mechanisms.
In one specific example, a detachment system may comprise a thermal detachment mechanism and a mechanical detachment mechanism. The thermal detachment mechanism may comprise a heater coil, heater loop, heater sleeve, or similar device configured to increase in temperature to break a tether connected to an implant. The mechanical detachment mechanism may comprise a sharp edge that is configured to selectively contact and cut or break the tether connected to the implant.
In another specific example, a detachment system may comprise a thermal detachment mechanism and an electrolytic detachment mechanism. The thermal detachment mechanism may comprise a heater coil, heater loop, heater sleeve, or similar device configured to increase in temperature to break a tether connected to an implant. The electrolytic detachment mechanism may include an electrolytically degradable member that is either the tether or connected to the tether, and which degrades when exposed to certain electrical current.
In another specific example, a detachment mechanism may comprise an electrolytic detachment mechanism and a mechanical detachment mechanism. The electrolytic detachment mechanism may include an electrolytically degradable member that is either the tether or connected to the tether, and which degrades when exposed to certain electrical current. The mechanical detachment mechanism may comprise a sharp edge that is configured to selectively contact and cut or break the tether connected to the implant.
In another specific example, a detachment system may comprise two independent thermal detachment mechanisms. The thermal detachment mechanisms may comprise a heater coil, heater loop, heater sleeve, or similar device configured to increase in temperature to break a tether connected to an implant.
In another specific example, a detachment mechanism may comprise two independent electrolytic detachment mechanisms. The electrolytic detachment mechanism may include an electrolytically degradable member that is either the tether or connected to the tether, and which degrades when exposed to certain electrical current.
In another specific example, a detachment mechanism may comprise two mechanical detachment mechanisms. The mechanical detachment mechanisms may comprise a sharp edge that is configured to selectively contact and cut or break the tether connected to the implant.
Any of the embodiments described in the specification may include a pusher that is moved axially or longitudinally within a tubular catheter or sheath. Generally, a pusher is an elongated member or body that is attached to an implant device and may include other components necessary for delivery and detachment of the implant. The pusher may or may not include a passage opening at its proximal and distal portions for a guidewire or other devices. In that respect, while the term pusher is used throughout this specification, the term may also encompass catheters or any elongated body that is sized and shaped for passage within a patient's vasculature.
The pusher may include two or more detachment mechanisms and is further moved via a proximal end of the pusher (e.g., via the pusher itself or a handle attached to the pusher).
Each of the attachment mechanisms may be considered to have an attached configuration and a detached configuration. In the attached configuration, the attachment mechanism is in a physical position, energized state (e.g., current delivery), temperature, or similar physical state that would otherwise prevent that attachment mechanism from releasing the implant attached to the pusher. For example, a thermal detachment system may not have current flowing through its components (e.g., a heater coil) and may be of an ambient temperature of the pusher. In another example, an electrolytic mechanism may be substantially non-degraded or non-corroded. In another example, a mechanical mechanism may have a shape or position of one or more of its parts that prevent release of the implant.
In the detached configuration, the attachment mechanism is in (or previously was in) a physical position, energized state (e.g., current delivery), temperature, or similar physical state that would, under normal operation, cause the implant to be released from the pusher. For example, a thermal detachment system may have (or previously had) current flowing through one or more of its components (e.g., a heater coil) and may be above an ambient temperature of the pusher (or previously was above an ambient temperature of the pusher). Thus, under normal conditions, after current flows through the components (e.g., heater coil) and the implant is released from the pusher, the attachment/detachment mechanism and components thereof may return to ambient temperature with the implant and pusher in the detached configuration. In another example, one or more components of an electrolytic mechanism (e.g., an electrolytic tether) may be partially or fully degraded or corroded. Under normal conditions, after the electrolytic mechanism degrades or corrodes the relevant component(s) (e.g., electrolytic tether) and the implant is released from the pusher, the attachment/detachment mechanism and components thereof may return to a neutral electrolytic state with the implant and pusher in the detached configuration. In another example, one or more components of a mechanical mechanism (e.g., sharp edge or blade) may change shape, position, or orientation to a detached configuration having a shape, position, or orientation of one or more of its parts that releases of the implant from the pusher.
While the attachment mechanism may be in a detached configuration and/or such a configuration may be initiated by a user (e.g., via a button or wire at a proximal portion of the pusher), failure of the detachment mechanism (or components related to it) may prevent the implant from being detached from the pusher. Hence, while under normal or intended circumstances the activation (or actuation or initiation) of one of the detachment mechanisms will result in the implant being detached from the pusher in the detached configuration, it is possible for the detachment mechanism to fail, and as a result, the implant would not be released or detached from the pusher despite activation (or actuation or initiation) of the detachment mechanism.
The detachment mechanisms of this specification discuss that the implant may be detached, released, and/or separated from the pusher. These terms may include complete detachment, release, and/or separation from the pusher. In the event of partial detachment, release, and/or separation (e.g., detachment failure or partial failure), the implant may still have a partial or residual connection or attachment to the pusher, and thus, a second detachment mechanism may be activated, actuated, or initiated to achieve full or complete detachment, release, and/or separation.
As previously discussed, one advantage of multiple detachment systems is that if one detachment system fails, a second can be actuated or activated. This failure to detach and subsequent actuation and activation may be performed solely by the user. For example, a user may use visual imaging (e.g., fluoroscopy) to determine if detachment has occurred and then manually actuate or activate a second detachment mechanism. This may allow the user to have control regarding whether use of the second detachment system is needed.
In another example, the detachment system may have a sensor that monitors and signals if the implant has detached from the pusher (e.g., by sensing inductance at a distal portion of the pusher). The detachment system may also, for example, have a mechanism that automatically activates the second detachment system after its sensor has determined that the implant has not detached after activation of the initially-activated first detachment system. In other words, the second detachment system can be an automatically actuated backup if the first detachment system fail to detach the implant. This may be advantageous in some situations if it is difficult to determine if detachment has occurred via imaging alone (e.g., fluoroscopy).
While a first and second detachment mechanism may be activated or actuated (or at least attempted to be activated or actuated) in a sequential manner, it may also be desirable for two detachment mechanisms to be activated or actuated simultaneously. For example, a single interface element (e.g., a button) may activate or actuate at least two detachment mechanisms at the same time. This may provide the user additional reassurance that implant detachment has occurred, especially in when imaging of the pusher and implant is difficult to view. In the case of detachment mechanisms that include a tether, it may be desirable to include mechanisms that break the tether close to or at the same location to prevent portions of the tether from separating from both the pusher and the implant.
Generally, a guidewire is initially advanced so that the distal end is located at a target location, then a catheter or sheath is advanced over the guide so that its distal end is located at the target location. The guidewire may be removed from the catheter, and the delivery system is advanced through the catheter so that its distal end is located near the target location.
A pusher of the delivery system may be distally advanced to push an implant (e.g., a microcoil) out of an outer sleeve or sheath. A first detachment mechanism within the pusher of the delivery system may be actuated or activated to attempt to detach the implant from the pusher, which preferably results in a complete or full detachment and separation of the implant from the pusher, but in some cases may only result in partial or incomplete detachment and separation, or possibly no detachment and no separation (e.g., if there is a break or interruption in the thermal or electrolytic detachment mechanism). In the event that activation of the first detachment mechanism results in anything less than a complete or full detachment and separation of the implant from the pusher, a second detachment system within the pusher of the delivery system may be actuated or activated to ultimately cause detachment and separation of the implant from the pusher and to deploy the implant at the target location of the patient.
While not required, the delivery system 100 may include a pusher 102, an outer sheath 103, and a handle 104. The pusher 102 is an elongated embodiment that is attached to an implant 126 at its distal end and attached to the handle 104 at its proximal end. The pusher 102 may be distally advanced relative to the tubular outer sheath 103 so as to push the implant 126 out of a distal end of the outer sheath 103 to a target location within a patient.
In an embodiment where electrical detachment mechanism is included, such as a heater, the handle 104 may include or be attached to a power supply (e.g., a battery) and include an actuation mechanism such as a button 104A to cause electrical current to pass into an electrical pathway of the pusher 102 to activate one of the detachment mechanisms.
In an embodiment where a mechanical detachment mechanism is included, a control wire 128 may pass through the handle 104 (if present) or out a distal end of the pusher 102. This allows a physician to push or pull the control wire 128 to actuate the mechanical detachment mechanism.
Generally, the pusher 102 includes a proximal portion 102B that extends much of its length, as well as a distal portion 102A. Both the distal portion 102A and the proximal portion 102B typically include an outer tubular layer 115 that may be comprised of a polymer or similar material. Typically, the proximal portion may also include other structural elements such as a structural coil 116 to provide some rigidity and pushability of the pusher 102.
In the present example, the distal portion 102A includes a first detachment mechanism 105 and a second detachment mechanism 106, either of which can be actuated or activated to release an implant 126 that is attached to the pusher 102.
The first detachment mechanism 105 is an electrically actuated or activated heater mechanism configured to break a tether 119 that is configured to secure the implant 126 to the pusher 102 and break the tether via application of heat. In that respect, a distal portion of the tether 119 is connected to the implant 126, such as via an adhesive 127. A proximal portion of the tether 119 may be connected to a proximal area of the pusher 102. This may be the structural coil 116, an internal core wire 114, components of the second detachment mechanism, or other proximal pusher components.
The tether 119 may be positioned through or near a heater coil 108 located in the distal portion 102A of the pusher 102 that is configured to selectively generate sufficient heat to cause breakage of the tether 119. In one example, the heater coil may have a helical shape that is connected to a first electrical wire 110 near its distal end and a second electrical wire 112 near its proximal end. The wires 110 and 112 extend and/or are in communication with a proximal end of the pusher 102 and may connect to a power source. For example, the handle 104 may include a battery power source that may selectively supply power to the wires 110 and 112 when the button 104A is actuated or activated, thereby creating heat in the heater coil 108. Optionally, the heater coil 108 may include a smaller diameter distal portion and a larger diameter proximal portion.
The second detachment mechanism 106 may provide an alternate mechanism for detachment of the implant 126. In the present example, both the first detachment mechanism 105 and the second detachment mechanism 106 are configured to break the tether 119, though this may not necessarily be required with other types of mechanism.
Specifically, the second detachment mechanism 105 is configured to move the tether 119 against a relatively sharp edge or blade 124 to cause breakage of the tether 119 and thereby release the implant 126. In one embodiment, moving the tether 119 against the blade edge 124 may generally include a mechanism having a control wire 128 that extends between the distal portion 102A and a proximal end of the pusher 102, such that when the user pulls the control wire 128, it causes breakage of the tether 119. Put another way, the sharp edge or blade 124 of the second detachment mechanism 105 is positioned near the tether 119 such that when in its detached configuration, the tether 119 is at least briefly positioned against the sharp edge or blade 124 to sever the tether 119.
Such a mechanical detachment mechanism may take many forms. For example, in
In one embodiment, the tether 119 may be positioned through two passages 118A and 120A within the pusher 102 to allow its position or angle within the pusher 102 to change. This angle or position change can be achieved by allowing one or both of the passages 118A and 120A to move relative to each other.
In the present example of
The movable member 120 includes the previously discussed passage 120A through which the tether 119 is positioned into and/or through. Depending on the configuration, the passage 120A may be offset from the center or axis of the pusher 102 so that when the passage 120A and moveable member 120 are moved longitudinally, they create a change in the position or angle of the tether 119.
In a first position configured not to break the tether and detach the implant 126, seen in
The angle of the tether 119 can be optionally increased to allow the tether 119 to have greater movement within the pusher 102 and against the blade edge 124. For example, a second, fixed member 118 with a tether passage 118A may be included distal of the movable member 120. The second fixed member 118 may be a circular disc or any other shape, such as a tube fixed to a side of the inside of the pusher. The passage 118A may be in a radial location different than, and optionally opposite of, the radial position of passage 120A so as to create a relatively large angle of the tether 119 within the pusher 102.
In operation, a distal end of the delivery system 100 is advanced distally to or near a target location within a patient. For example, in
When the operator (e.g., physician) determines that the implant 126 should be detached, one of the detachment mechanisms 105, 106 are activated. Again, the operator may select the detachment mechanism 105, 106 based on multiple factors or may default to a first detachment mechanism and then use the second detachment mechanism for backup purposes if the first detachment mechanism should fail. Alternatively, in some embodiments, the operator may select and activate both detachment mechanisms 105 and 106 simultaneously.
For example, the heater coil 108 is activated by pressing button 104A on the handle 104, causing electrical current to flow through the heater coil 108. As the heater coil 108 increases in temperature, it causes the tether 119 to break.
If, for some reason, the tether 119 does not break when the detachment mechanism 105 is actuated or activated, the detachment mechanism 106 can be actuated or activated. For example, the control wire 128 can be pulled from a proximal portion of the pusher 102 and/or handle 104. As the control wire 128 is pulled, it changes a position and/or angle of the tether 119 in the distal portion 102A of the pusher 102 so that the tether 119 moves against the blade edge 124 to cut or break the tether 119. Whether the first detachment mechanism 105 or the second detachment mechanism 106 breaks the tether 119, the implant 126 is ultimately detached and the delivery system 100 can be removed from the patient.
As previously discussed, other combinations of detachment mechanism are also possible.
For example,
In another example,
A tether 119 has been described in this specification. This term may also be considered a monofilament, thread, wire, or strand.
A heater or heater coil is described in this specification. This term may also be considered a heater tube, a heater loop, a heater wire, or any resistive element in any shape within a pusher that is capable of generating heat when supplied with electrical current.
A pusher is described in this specification. This term may also be considered any elongated body composed of any material, including polymer, metal, structural coils, electrical wires, or similar components. While the disclosed embodiments generally refer to the implant as being attached to the pusher, the implant could be attached to another component of the delivery device without changing the operation of the detachment mechanisms described herein. Within this context, other components of the delivery device may effectively act as a pusher as described in this specification.
While the present specification has generally discussed implant detachment systems with two or more detachment mechanisms, it is also contemplated that a single detachment system may also be included. For example,
Additional uses and descriptions of the embodiments and examples described herein are provided below.
The delivery system for a medical implant may comprise: an elongated pusher; an implant positioned near a distal end of the elongated pusher; a first detachment mechanism configured to release the implant from the elongated pusher; and, a second detachment mechanism configured to release the implant from the elongated pusher.
The delivery system for a medical implant may comprise: an elongated pusher having a first detachment mechanism and a second detachment mechanism; and, an implant positioned near a distal end of the elongated pusher; wherein the implant has a detached state from the elongated pusher initiated by the second detachment mechanism when the first detachment mechanism fails to initiate the detached state.
A method of delivering a medical implant may comprise: advancing a distal end of a delivery system to a target area of a patient; actuating a first implant detachment mechanism within a pusher of the delivery system; and, actuating a second implant detachment mechanism within the pusher of the delivery system. The method may further comprise: wherein the actuating the first implant detachment mechanism comprises actuating or activating a heater. The method may further comprise: wherein the actuating the second implant detachment mechanism comprises actuating or activating a mechanical detachment system.
Although the invention has been described in terms of particular embodiments and applications, one of ordinary skill in the art, in light of this teaching, can generate additional embodiments and modifications without departing from the spirit of or exceeding the scope of the claimed invention. Accordingly, it is to be understood that the drawings and descriptions herein are proffered by way of example to facilitate comprehension of the invention and should not be construed to limit the scope thereof.
This application claims benefit of and priority to U.S. Provisional Application Ser. No. 63/163,610 filed Mar. 19, 2021 entitled Recoverable Electro Thermal Detachment Systems, which is hereby incorporated herein by reference in its entirety.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2022/071230 | 3/18/2022 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 63163610 | Mar 2021 | US |
