Patent Application
20180221030
The present invention relates to methods and devices to treat endovascular and non-endovascular defects including but not limited to parent vessel occlusion, cerebral and endovascular aneurysms, arterial-venous malformations, embolism or prevention of blood flow to tumors or other portions of the body. Treatment of other medical conditions including congenital defects such as Atrial and Ventricular Septal Defects, Patent Ductus Arteriosus and Patent Foramen Ovale are also included. The devices made in accordance with the invention are particularly well suited for delivery through a catheter or the like to a remote location in a patient's body.
The devices described in this invention are intended, among other therapies, for treatment of defects in the arteries and veins. The defects include aneurysms, fusiform aneurysms. arteriovenous malformations, arteriovenous fistulas, cavernous fistulas and dissections, as well as other hyper-vascular lesions such as head and neck tumors, etc. These defects cause a variety of symptoms, ranging from pain, weakness, headache, vision loss, and stroke to death. Preferably, these defects would be treated with devices and methods of the present invention that leave the associated parent artery or vein intact and patent, so it may continue to supply blood and function normally. However, in many cases, a patient's condition may dictate that immediate cessation of blood flow is required.
When parent artery preservation is not advisable, the devices and methods of the present invention can be used for parent artery occlusion (PAO). Parent artery occlusion is accomplished by quickly and securely closing off a length of a blood vessel near the defect that preferably results in immediate and complete blockage of blood flow to the defect, and permanent isolation of the blood vessel segment near the defect. Parent artery occlusion is sometimes referred to more broadly as parent vessel occlusion to encompass occlusion of both arteries and veins.
Several endovascular devices and techniques have been developed to accomplish parent artery occlusion. Detachable balloons have previously been used for parent artery occlusion but were not successful because of leakage and unexpected deflation, leading to major complications. Occlusive coils have been used to pack fusiform aneurysms and cavernous fistulas, but often do not result in immediate occlusion. As a result, trickling blood flow which occurs for several minutes while the patient's blood is coagulating around the mass of coils may lead to creation and migration of thrombus from the mass of coils.
Vascular plugs have also been used to accomplish parent artery occlusion. Currently available plugs such as the Amplatzer vascular plug are difficult to deploy and are size-sensitive. Also, the open-mesh construction of these vascular plugs may result in dislodgement of thrombus as it is forming on the plug, leading to downstream embolization of the occluded artery.
Mechanical embolization devices such as filters and traps have been proposed in the past to achieve parent artery occlusion and are disclosed in U.S. Pat. Nos. 3,874,388; 5,334,217; 4,917,089 and 5,108,420 among others, however, deployment of these devices and/or recapture into the delivery catheter is difficult, further limiting the effectiveness of these devices.
An aneurysm is an abnormal bulge or ballooning of the wall of a blood vessel, which most commonly occurs in arterial blood vessels. Aneurysms typically form at a weakened point of a wall of a blood vessel. The force of the blood pressure against the weakened wall causes the wall to abnormally bulge or balloon outside. Aneurysms, particularly cranial aneurysms, are a serious medical condition because they can apply undesired pressure to areas within the brain. Additionally, there is always the possibility that the aneurysm may rupture or burst leading to serious medical complications including death.
More recently, less invasive intravascular catheter techniques have been used to treat endovascular and cranial aneurysms. Typically, these techniques involve use of a catheter to deliver platinum coils. currently the most popular embolic devices, to a treatment area within the vasculature. In the case of a cranial aneurysm, a delivery catheter is inserted through a guiding catheter to the site of the cranial aneurysm. A platinum coil attached to the pusher wire is pushed through the delivery catheter, and into the aneurysm. Once platinum coils have been deployed within the aneurysm, blood clots (thrombus) are formed. Formation of such blood clots will seal off the aneurysm preventing further ballooning or rupture. The coil deployment procedure is repeated until the packing density within the aneurysm reaches about 30% or more of the volume.
There are a variety of materials and devices which have been used for treatment of vascular aneurysms, including platinum and stainless-steel coils, polyvinyl alcohol sponges, and other mechanical devices. One type of widely-used occlusion implant is helical wire coils described in U.S. Pat. Nos. 4,994,069 and 6,299,627. Occlusion coils having attached fibrous elements are disclosed in U.S. Pat. Nos. 5,833,705; 5,304,194; 5,354,295; 5,122,136 and describe electrolytically detachable occlusion implants. Occlusion coils having little or no inherent secondary shape have been described in U.S. Pat. Nos. 5,690,666; 5,826,587; and 6,458,119 while U.S. Pat. No. 5,382,259 describes non-expanding braids covering a primary coil structure.
Occlusion implant compositions comprising one or more expandable hydrogels have also been described in U.S. Pat. No. 6,960,617; 6,113,629; 6,602,261 and 6,238,403 which disclose a plurality of expansible hydrogel elements disposed at spaced intervals along a filamentous carrier. Other U.S. Pat. Nos. 6,616,617; 6,475,169; 6,168,570 and 6,159,165 disclose multi-stranded micro-cable devices, where one or more of the strands may be an expandable material. Occlusion implants made of a combination of braid with underlining coils that should serve as a blood diverter when deployed inside the aneurysm are described in U.S. Pat. Nos. 9,011,482 and 9,060,777.
Despite the above, a need remains for occlusion implants having a better packing capability and filling density, and preferably made of a single occlusive device suitable for multiple clinical applications, either for parent vessel occlusion, neurological or other endovascular aneurysm occlusion, or other defects in the human body.
The devices and methods described in the present invention are suitable for parent artery occlusion within the human endovascular system, including cerebral arteries and veins, and may be used to treat aneurysms throughout the body.
The embolization devices of the present invention include detachable tandem embolization devices (TED), occlusion implants comprising at least one expandable braid and at least one coil, detachable mesh endo-frame devices (MEF), and occlusion implants comprising at least one expandable braid with a constraining member inside the braid.
The tandem embolization devices (TED) or occlusion implants of the present invention comprise at least one elongate expandable braid and at least one coil. The occlusion implants are attached to a pusher member with a detachable electro-mechanical attachment means and positioned inside the delivery catheter. When released/detached from the pusher member and outside of the delivery catheter, the occlusion implant expands to its unrestrained shape and/or to the extent allowed by the surrounding treatment area. In one primary embodiment, deployment of a distal expandable braid(s) from the delivery catheter forms a pre-shaped anchoring structure that results in larger space coverage, while the attached coil(s) provides a final packing of the treatment area and immediate occlusion of the artery or aneurysm. In another primary embodiment; deployment of a distal coil from the delivery catheter forms a pre-shaped anchoring structure around the treatment area, while the attached expandable braid provides a final packing of the treatment area and immediate occlusion of the artery or aneurysm.
The occlusion implants of the present invention include at least one elongate expandable braid attached to a pusher member with a detachable mechanical attachment means and positioned inside the delivery catheter.
One objective of the present invention is to provide an occlusion implant that at least partially expands to occupy a greater volume within the treatment area than conventional helical coils, thus providing an effective engaging/anchoring edifice combined with a large volumetric area to promote quick blood clotting.
In one embodiment of the present invention, an occlusion device or system for occluding endovascular defects comprises a delivery catheter having a distal end and a proximal end, an elongate occlusion implant extending longitudinally within the delivery catheter and configured to be pushed through and out of the delivery catheter and retrieved back into the distal end of the delivery catheter using a pushing member. The occlusion implant comprises at least two regions: a first distal region comprised of an expandable braid element and a second elongate region proximal to the first distal braid and comprised of a non-expandable helical coil. Such a hybrid structure or tandem structure of a braid and a coil at least partially expands to a larger volumetric area when pushed out of delivery catheter. The expanded braid is configured to have a pre-set expanded longitudinal shape when released from the delivery catheter. The expanded braid may also have a bulbous shape resembling a bulb in shape, or rounded or swollen, as well as, any shape suitable to fill out a treatment area. The occlusion implant traverses concomitant bends as the delivery catheter when delivered through the delivery catheter to the treatment location.
In another embodiment, the expandable braid has a collapsed configuration when held inside the delivery catheter and an expanded configuration that is radially larger than the second elongate helical coil region when in a released configuration outside the delivery catheter.
In another embodiment, the braid is connected to the helical coil, and such braid and helical coil connections may be formed by one or more of the following methods; directly connected, using an intermediate member, and a combination of both. Such connection may be achieved by bonding, fusing, welding, soldering, gluing or other mechanical or thermal means.
In another embodiment, the helical coil may be wound from an extension of one or more of the braid strands, thereby making the braid and coil a continuous mechanical structure and thus eliminating the need for any additional bonded connection between the two.
In yet another embodiment, the braid of the occlusion implant has a longer length when in the collapsed configuration inside the delivery catheter than its actual length when deployed outside the delivery catheter.
In another embodiment, the braid has a formed distal tip wherein the braid strands are prolapsed back into the distal inside diameter of the braid, thereby minimizing delivery friction through the catheter, yet enhancing anchoring of the implant in the patient while minimizing the potential for vessel trauma during deployment.
In yet another embodiment, the braid has a formed distal tip that prevents the very distal section of the braid from fully expanding when deployed from the delivery catheter. Such a distal tip may be made of one of the following materials: metal, polymer, rubber, adhesive or a combination of thereof.
In another embodiment, at least one radiopaque marker is positioned along the occlusion implant including at any of the following locations: the distal end, the proximal end, along the length of the implant, or any combination thereof. A radiopaque marker may be positioned inside the occlusion implant, on the outside surface thereof, or on both locations. A radiopaque marker may include a radiopaque solder.
In yet another embodiment, the helical coil is attached proximally to a pushing member (pusher) located at least partially within the delivery catheter. The pushing member is constructed to push the occlusion implant out of the delivery catheter, deploy and retrieve the occlusion implant from and into the delivery catheter when needed.
In another embodiment, at least one elongate constraining member is extended at least partially through the helical coil, and it is attached to or near the distal end of the helical coil and to or near to the proximal end of the helical coil. Alternatively, or in addition, at least one elongate constraining member is extended through the occlusion implant and it is attached distally to or near the distal end of the braid and proximally to or near the proximal end of the helical coil.
In yet another embodiment, the elongate constraining member has variable stiffness along its length, being stiffer distally and more flexible proximally. Alternatively, the elongate constraining member has a variable flexibility along its length, with more flexibility distally and less flexibility proximally. The elongate constraining member can also have a more flexible proximal end and less flexible distal end.
In another embodiment, the elongate constraining member may enhance the thrombogenicity of the implant when deployed in endovascular or non-endovascular defects.
In yet another embodiment, the elongate constraining member may enhance the radiopacity of the occlusion implant by virtue of its composition.
In another embodiment, the braid comprises a proximally tapered section to facilitate deployment and retrieval of the braid from the delivery catheter.
In yet another embodiment, the helical coil has variable flexibility, being stiffer distally and more flexible proximally. Alternatively, the helical coil may be more flexible distally and less flexible proximally.
In yet another embodiment, the first braided region is made of a braid that has a diameter that is at least 1.3 times larger than the diameter of the second region helical coil when the occlusion implant is released from the delivery catheter.
In yet another embodiment, the braid is formed from a plurality of strands of Nitinol wire having an outside diameter between 0.0003 inches and 0.010 inches. The braided material is formed from a plurality of strands having a pore size formed between strands in the expanded configuration of less than about 0.2 square mm. The braid may be formed from a plurality of strands of Nitinol wire having multiple wire strands of the same dimensions or of different dimensions braided into the shape using a circular wire, oval wire, flat wire and any other suitable wire configuration, or combinations thereof.
In another embodiment, the expanded braid may be configured to have a pre-set expanded diameter having a cross-sectional (transverse) shape in the following configurations: tubular, circular shape, bulbous shape, onion-shape resembling onion or any other shape including but not limited to non-circular, for example, oval, flat, rectangular, tear-shaped, twist-shape and other suitable shapes.
In another embodiment, the occlusion implant is at least partially configured to have pre-set longitudinal shapes including a curved shape, three-dimensional shape, helical shape, non-linear, random shape and any non-linear shape.
In yet another embodiment, the distal braid is configured to assume a radial configuration that opposes the inside wall of the defect after deployment from the delivery catheter, thereby creating a radial frame. Such a radial frame may anchor in the wail to prevent the occlusion implant from being repositioned by blood flow while the proximal helical coil fills the defect space upon deployment from the delivery catheter.
In another embodiment, the first region braid has an open braid on the distal end.
In yet another embodiment, at least one radial elongate constraining member is positioned at least one location around and along the braid region.
In another embodiment, an alternative or additional friction reduction means are located within the proximal end of the braid and the distal end of the helical coil to improve ease of deployment and retrieval of the occlusion implant into and out of the delivery catheter.
In another embodiment, the braided member is formed from a plurality of strands made of a monofilament wire having a closed pitch and braid angle of 35 degrees or less in the collapsed configuration inside the delivery catheter. Such braid may have between 8 and more than 200 strands.
The braided member may be configured to have an expanded braid angle between about 25-120 degrees and a diameter between about 0.5 mm to about 50 mm or more.
In another embodiment of the present invention, the occlusion implant includes bioactive coating.
In another embodiment of the present invention, an occlusion device or system for occluding endovascular defect comprises a delivery catheter having a distal end and a proximal end, an elongate occlusion implant extending longitudinally within the delivery catheter and configured to be pushed through and out of the delivery catheter and retrieved back into the distal end of the delivery catheter using a pushing member. The occlusion implant comprises a plurality of regions with at least the first distal region comprised of a non-expandable helical coil and the second elongate region proximal to the first distal region comprised of an expandable braid. The occlusion implant traverses concomitant bends as the delivery catheter when pushed through the delivery catheter to the treatment area.
In another embodiment, the plurality of radial elongate constraining members along the length of the occlusion implant may be comprised of a bioabsorbable material, such that the constraining members help to minimize friction during delivery, but then dissolve to allow full expansion and greater packing volume of the implant post deployment.
In yet another embodiment, the braid portion of the occlusion device or system comprises a tapering configuration formed during fabrication by the braid being woven over a tapered assembly mandrel. Such tapering configuration may taper down from proximal to distal, from distal to proximal, or have any suitable variations of tapering diameters.
In another embodiment of the present invention, an occlusion device or system for occluding endovascular defects comprises a delivery catheter having a distal end and a proximal end, an elongate occlusion implant extending longitudinally within the delivery catheter and configured to be pushed through and out of the delivery catheter and into the delivery catheter using a pushing member. The occlusion implant comprises an elongate expandable braid with a region having plurality of radial elongate constraining members along its length having different expanded diameters. The occlusion implant traverses concomitant bends as the delivery catheter when delivered through the delivery catheter to the treatment location.
In another embodiment, the occlusion implant is made of a braid and includes an elongate constraining member extending along the occlusion implant having a distal end attached to or near the distal end of the braid, and a proximal end attached to near the proximal end of the braid. Such elongate constraining member may have a relatively straight configuration when the occlusion implant is inside of the delivery catheter, and then assume a wavy configuration when the occlusion implant is outside of the delivery catheter.
In another embodiment, an occlusion device or system tar occluding endovascular defects comprises a delivery catheter having a distal end and a proximal end, an elongate occlusion implant extending longitudinally within the delivery catheter and configured to be pushed through and out of the delivery catheter and retrieved back into the delivery catheter using a pushing member. The occlusion implant comprises a plurality of expandable braids and helical coils having at least one elongate constraining member along its length. The occlusion implant and constraining member(s) traverse concomitant bends as the delivery catheter when delivered through the delivery catheter to the endovascular defect.
In another embodiment, at least one elongate constraining member may alternatively or in addition include thrombogenic polymer fibers.
In yet another embodiment, the occlusion implants of the present invention may include components and materials that promote thrombogenicity.
In another embodiment of the present invention, an occlusion device or system for occluding endovascular defects comprises a delivery catheter having a distal end and a proximal end, an elongate occlusion implant extending longitudinally within the delivery catheter and configured to be pushed through and out of the delivery catheter and retrieved back into the distal end of the delivery catheter using a pushing member. The occlusion implant comprises at least two expandable braids: a first distal expandable braid and a second expandable braid, wherein both expanded braids are configured to have a pre-set expanded longitudinal shape when released from the delivery catheter. The occlusion implant traverses concomitant bends as the delivery catheter when delivered through the delivery catheter to the treatment location.
In yet another embodiment, the occlusion implant has at least two braids connected together or one continuous braid with two different longitudinal diminutions that include the following dimensional options: the distal braid is larger than the proximal braid, the distal braid is smaller than the proximal braid, or the distal braid has the same dimension as the proximal braid.
In another embodiment, an occlusion device or system for occluding defects in humans comprises a delivery catheter having a distal end and a proximal end, an elongate occlusion implant extending longitudinally within the delivery catheter and configured to be pushed through and out of the delivery catheter and retrieved back into the distal end of the delivery catheter using a pushing member. The occlusion implant can partially expand having a larger volumetric area when pushed out of delivery catheter. The occlusion implant may have at least one expandable braid and at least one coil. The braid may have a primary outside diameter and a primary braid angle after being manufactured, and the braid may further be reconfigured to have a secondary braid configuration having a secondary outside diameter that has a smaller braid angle than the primary braid angle, and the expandable braid and coil may be attached together.
In yet another embodiment, there is an intermediate external tube member between the proximal end of the expandable braid and the distal end of the coil to connect the braid and the coil. The proximal end of the braid may be positioned inside the intermediate tube member on one end, and the distal end of the coil may be positioned inside the tube on the opposite end. The intermediate external tube may be made of one of the following materials: polymer, metal, metal alloy, rubber, ceramic or any combination thereof.
In another embodiment, the braid and coil may be in contact, or the braid and coil may be spaced apart.
In another embodiment, the secondary braid angle may be smaller than 60 degrees when in the expanded configuration, and preferably around 50 degrees. The braid may be made in one of the following patterns: 1 over-1 under wire, 2 over-2 under wires, 1 over-2 under wires, 2 over-2 under wires, 1 over-3 under wires; 2 over-3 under wires, 3 over-3 under wires, 1 over-4 under wire, 2 over-4 under wires, 3 over-4 under wires, 4 over-4 under wires and any combination thereof.
In yet another embodiment, an occlusion device or system for occluding defects in humans comprises a delivery catheter having a distal end and a proximal end, an elongate occlusion implant extending longitudinally within the delivery catheter and configured to be pushed through and out of the delivery catheter and retrieved back into the distal end of the delivery catheter using a pushing member. The occlusion implant at least partially expands having a larger volumetric area when pushed out of delivery catheter. The occlusion implant may be made of at least one expandable braid and one coil. The expandable braid(s) may be configured to have a pre-set expanded longitudinal shape when released from the delivery catheter, and the coil(s) may be at least partially extended inside the braid(s), and the braid(s) and coils) are connected together on the proximal end of the braid
In another embodiment, the coil is extended along the entire braid length. The braid and the coil traverse concomitant bends when pushed through and retrieved back into the delivery catheter.
In another embodiment, the proximal end of the braid is not affixed to the coil and can be re-positioned back and forth along the coil as needed while the distal end of the braid and the coil are affixed together.
In yet another embodiment, the occlusion device or system may be comprised of two separate coils: one proximal coil located proximal to the expandable braid, and one inside coil located inside the braid. The inside coil may be attached to the braid on the distal end and on the proximal end, while the proximal coil is attached to the proximal end of the braid. The inside coil and the proximal coil may have several configurations, including but not limited to, straight, not heat pre-shaped, heat pre-shaped, and combinations thereof.
In another embodiment, an occlusion device or system for occluding endovascular defects comprises a delivery catheter having a distal end and a proximal end, an elongate occlusion implant extending longitudinally within the delivery catheter and configured to be pushed through and out of the delivery catheter and retrieved back into the distal end of the delivery catheter using a pushing member. The occlusion implant may at least partially expand having a larger volumetric area when pushed out of delivery catheter. The occlusion implant may include at least one expandable braid having a distal end and a proximal end and at least one constraining member extended longitudinally. The braid may be configured to have a pre-set expanded shape when released from the delivery catheter. The constraining member may be attached to the distal end of the braid and to the proximal end of the braid and may assume a pre-set expanded shape of the braid when pushed outside the delivery catheter. The braid and the constraining member traverse concomitant bends as the delivery catheter when pushed through and retrieved back into the delivery catheter.
In another embodiment, an occlusion device or system for occluding endovascular defects comprises a delivery catheter having a distal end and a proximal end, an elongate occlusion implant extending longitudinally within the delivery catheter and configured to be pushed through and out of the delivery catheter and retrieved back into the distal end of the delivery catheter using a pushing member. The occlusion implant may at least partially expand having a larger volumetric area when pushed out of delivery catheter. The occlusion implant may have at least one expandable braid having a distal end and a proximal end and at least one constraining member extended longitudinally, the constraining member may be configured to have a pre-set expanded shape when released from the delivery catheter. The constraining member may be attached to the distal end of the braid and to the proximal end of the braid. The expandable braid may assume a pre-set expanded shape of the constraining member when pushed outside the delivery catheter, and the braid and constraining member may traverse concomitant bends as the deliver), catheter when pushed through and retrieved back into the delivery catheter.
The constraining member and the braid may also both have thermally pre-shaped configurations, and both assume a similar configuration after release from the delivery catheter.
In another embodiment, the occlusion implant comprises a plurality of braids with varied expanded dimensions.
In another embodiment, a method for occluding endovascular defects is provided that includes placing a delivery catheter having an occlusion device or system at the treatment site, wherein the occlusion device or system comprises an occlusion implant and an attached pusher member. Next, the occlusion implant is deployed into the endovascular defect using the pusher member, and then detached inside the endovascular defect. The occlusion device or system traverses concomitant bends as the delivery catheter before deployment.
In another embodiment, the occlusion implant including a expandable braid and/or a helical coil is pre-shaped into a three-dimensional configuration and, when deployed into the treatment area, anchors into surrounding tissue to fill the space and limit blood flow.
In another embodiment, a method for occluding endovascular defects is provided that includes placing a delivery catheter at the treatment site and introducing an occlusion device or system through the delivery catheter to the treatment site. The occlusion device or system comprises an occlusion implant and has an attached detachable pusher member. The occlusion implant comprises at least one expandable braid and one attached helical coil. The occlusion implant is deployed into the endovascular defect using the pusher member, and then detached inside the endovascular defect. The occlusion assembly traverses concomitant bends as the delivery catheter when introduced through the delivery catheter to the endovascular defect.
In another embodiment, a method for occluding endovascular defects comprises deploying the occlusion implant from the delivery catheter, and detaching the occlusion implant, wherein the occlusion implant at least partially expands creating a larger volumetric area than before deployment from the delivery catheter, and wherein the occlusion implant traverses concomitant bends as the delivery catheter while inside the delivery catheter.
In yet another embodiment, occlusion implants of the present invention are configured to resist unacceptable migration from the treatment site following implantation. Initially, device migration is inhibited by anchoring with tissues/vessel at the implantation site, and then by thrombus formation around the occlusion implant.
In another embodiment, an elongated radiopaque component is extended within the expandable braid that comprises one or more micro-coils placed on the core wire and within the braid structure.
In some embodiments, an occlusion implant is configured to cause an acceptable amount of trauma to tissues at the treatment site upon deployment, which can serve to initiate a localized healing to enhance the growth of new patient tissue at the treatment site.
In another embodiment, a method for occluding endovascular defects comprises deploying an occlusion implant from the delivery catheter and detaching the occlusion implant at the treatment area. The occlusion implant at least partially expands, creating a larger volumetric area than before deployment from the delivery catheter. The distal part of the occlusion implant expands upon release from the delivery catheter while the proximal part of the occlusion implant does not expand upon release from the delivery catheter, and the occlusion implant assumes a pre-set configuration upon release from the delivery catheter. The occlusion implant traverses concomitant bends as the delivery catheter before deployment from the delivery catheter.
In another embodiment, a method for occluding endovascular defects comprises deploying the occlusion implant from the delivery catheter and detaching the occlusion implant at the treatment area. The occlusion implant at least partially expands creating a larger volumetric area than before deployment from the delivery catheter, and the distal part of the occlusion implant has the same size before and after delivery from the delivery catheter while the proximal part of the occlusion implant expands upon release from the delivery catheter. The occlusion implant assumes a pre-set configuration upon release from the delivery catheter; and the occlusion implant traverses concomitant bends as the delivery catheter before deployment from the delivery catheter.
In another embodiment, a method for occluding endovascular defects comprises deploying the occlusion implant from the delivery catheter and detaching the occlusion implant at the treatment area. The occlusion implant at least partially expands creating a larger volumetric area than before deployment from the delivery catheter, the distal part of the occlusion implant is not expandable upon release from the delivery catheter, the mid-portion of the occlusion implant expands upon release from the delivery catheter, and the proximal part of the occlusion implant does not expand upon release from the delivery catheter. The occlusion implant assumes a pre-set configuration upon release from the delivery catheter, and the occlusion implant traverses concomitant bends as the delivery catheter before deployment from the delivery catheter.
The occlusion devices or systems of the present invention may be suitable for any one of the following defects: parent vessel occlusion, cerebral and endovascular aneurysms, arterial-venous malformations, embolism, occlusion of blood flow to tumors, Atrial and Ventricular Septal Detects, Patent Ductus Arteriosus and Patent Foramen Ovale.
The distal tip 110 may be made of one of the following materials: metal, polymer, rubber, adhesive or a combination thereof. One or more radiopaque markers may be positioned along the implant 101 for a better fluoroscopic visibility during deployment or retrieval of the implant 101 inside the delivery catheter 102 including; a radiopaque marker 111 located on the distal end 105 of the braid 104; and a radiopaque marker 112 located on the proximal end 109 of the helical coil 107. Optionally, another radiopaque marker may be located on the proximal end 106 of the braid 104 (not shown) to enhance fluoroscopic visibility of the proximal end 106 of the braid 104 and the distal end 108 of the helical coil 107. Optionally, a radiopaque solder may be used along the braid 104, including the distal end 105 and the proximal end 106, to enhance radiopacity. An elongate constraining member (see below) may enhance the radiopacity of the occlusion implant by virtue of its composition.
The helical coil 107 may be wound from an extension of one or more of the braid strands (not shown), thereby making the braid 104 and coil 107 a continuous mechanical structure and thus eliminating the need for any additional bond connection between the two.
The occlusion implant 101 may include a plurality of regions including braids 104 and helical coils 107 combined in any suitable order from the distal end to the proximal end (not shown).
The proximal end 109 of the helical coil 107 is attached to a pushing member 103 located at least partially within the delivery catheter 102 that functions to deliver the occlusion implant 101 to the treatment location. The pushing member 103 (pusher) is constructed to push the occlusion implant 101 out of, and to retrieve the occlusion implant 101 back into, the distal end 113 of the delivery catheter 102. The pushing member 103 may be made of one of the following materials: wire, tube, wire strand, metal, metal alloy, polymer, polymer knit or combination thereof. The distal end 114 of the pushing member 103 is attached to a detachment junction 115. The detachment junction 115 is configured for disconnection of the occlusion implant 101 from the pushing member 103 when the occlusion implant 101 is satisfactorily positioned and ready for deployment at the treatment area.
Detachment methods to disconnect the occlusion implant 101 from the pusher 103 may include but are not limited to electrolyte detachment (electrical current); mechanical detachment (movement, screw or pressure); thermal detachment (localized delivery of heat); and radiation detachment (electromagnetic radiation). The detachment junction 115 may be attached to the occlusion implant 101 directly or by using an intermediate member such as polymer or fiber material (not shown).
Alternatively, the detachment junction 115 may be positioned anywhere along the length of the occlusion implant 101 (not shown). The distal end 108 of the helical coil 107 is attached to the proximal end 106 of the braid as shown in detail in
The delivery catheter 102 having a distal end 113 provides a shield and serves as a delivery vehicle to deliver the occlusion implant 101 to the treatment location. The delivery catheter 102 may have an inner diameter between 0.015 inches and about 0.100 inches and its inside layer should preferably be made of a low friction polymer material to ease the delivery of the occlusion implant 101 to the treatment location. Polymer materials having a low friction coefficient may include but are not limited to Teflon, Polyamide, Low Density Polyethylene, Polytetratluoroethylene (PTFE), Polyoxymethylene (Delrin).
When the occlusion implant 101 is in a compressed configuration as shown in
The proximal end 106 of the expanded braid 200 is connected to the distal end 108 of the helical coil 107 via a connecting feature 201. The proximal end 106 of the braid 200 may be positioned either inside of the distal end 108 of the helical coil 107 or overlap the distal end 108 of the helical coil 107 (not shown). The connection feature 201 between both sections may be formed by one or more of the following methods; bonding, fusing, welding, soldering, gluing, other mechanical means or any combination of all.
The expandable braid 104 of the occlusion implant 101 has a greater length when at its collapsed configuration inside the delivery catheter 102 as shown on
At least one elongate constraining member 203 that prevents the helical coil 107 from stretching is extended through the helical coil 107 and it is attached to or near the distal end 108 of the helical coil 107 and to or near the proximal end 109 of the helical coil 107. Alternatively, or in addition, at least one elongate constraining member 204 may be extended through the occlusion implant 101 to prevent the whole implant from stretching and from damage. The constraining member 204 may be attached at one end to or near the distal tip 110 of the braid 104, and at other end proximally to or near the proximal end 109 of the helical coil 107. The elongate constraining members 203 and 204 may be made of a single wire, multiple wires, strands, coils, tubes, polymer rod, knit, woven, braid and have several configurations including but not limited to: straight, bent, coiled, helical, sinusoidal, wave or any combination thereof. Such elongate constraining members may be made of metal, metal alloy, polymer or a combination of the above.
The elongate constraining members 203 and 204 may have variable stiffness along their length, such as stiffer distally and more flexible proximally, stiffer proximally and more flexible distally, or a stiffness that constantly changes along its length. Alternatively, the elongate constraining members may comprise of a plurality of members made of wire, strands, coils, tubes, polymer rod, braid attached together, optionally including radiopaque members.
The open-ended braid 301 will enhance engagement of its distal end 302 into the tissue within the treatment area and serve as a distal anchor of the implant 300. There is no safety issue of perforating the treatment area with an open braid 302 because the opening or terminating strands of the occlusion implant 300 are made of a very fine wire.
The expandable braids of the present invention may be made of a plurality of wire strands having a thickness that is between about 0.0005 inches and about 0.010 and the same dimensions or different dimensions braided into the desirable shape. The expandable braids of the present invention may be constructed of wire strands made of the following materials: metals, alloys, polymers, a shape memory material (e.g., Nitinol), cobalt-chromium alloys, Platinum, Platinum-Iridium alloys, polymers (e.g., Nylon, Polyester, etc.) or combinations of any. The expandable braid may be formed from a plurality of wires having multiple wire strands of the same dimensions or different dimensions braided into the desirable shape using circular wire, oval wire, flat wire and any other suitable wire configuration. The helical coil may be formed from a single wire or a plurality of wires having the same dimensions or different dimensions using circular wire, oval wire, flat wire and any other suitable wire configuration.
The braids 104, 301 may be formed from a plurality of strands made of a monofilament wire having a closed pitch and braid angle of 35 degrees or less in the collapsed configuration when inside the delivery catheter. Braid angle XX as shown in
The overall radial diameters of the braid 301 of the occlusion implant 300 in the expanded position as shown in
The helical coils of the present invention may be wound from one or more wires made from one of the following materials: metals, alloys, polymers, shape memory materials (e.g., Nitinol), cobalt-chromium alloys, Platinum, Platinum-Iridium alloys, polymers (e.g., Nylon, Polyester, etc.) or combinations of any.
The helical coil may be prepared by wrapping a suitable wire about a cylindrical or conical mandrel. Any loose end of a helical wire coil may be placed axially through the core of the helix and bound to another part or coil using, e.g., by heat, adhesives, and/or mechanical means. Alternatively, or in addition, a thrombogenic element (e.g., particles, radial filaments, polymer fibers etc.) may be attached to portions of the coil 107 by typing/adhering them to the coil 107 (not shown). The elongate constraining member 306 is attached to or adjacent the distal end 302 of the open braid 301 at the attachment area 307 and to (or adjacent) the proximal end 109 of the helical coil 107 at the attachment point 308 using conventional attachment methods, including but not limited to bonding, welding, and heat fusing.
Additional thrombogenic elements (e.g., particles, radial filaments, polymer fibers etc. may he attached to at least a portion of the elongate constraining member 306 using any suitable binding technique; e.g., by tying or otherwise adhering them to the elongate constraining member 306 (not shown).
The delivery of the occlusion implant 400 to the treatment area and outside of the delivery catheter 102 becomes more difficult when friction between the outer surface of the braid 401 and the inner wall 408 of the delivery catheter 102 is high. The longer the occlusion implant 400 is, and the bigger the outer diameter of the braid 401 in the expanded configuration, the more challenging the delivery and retrieval of the occlusion implant 400 would be. Both these attributes (occlusion implant length and expanded braid size) play a very important role in clinical applications because a greater implant volumetric size will facilitate better occlusion implant engagement structure/edifice, and the larger surface area for promotion of blood clotting.
Use of a surface coating may be helpful to reduce friction between the braid 401 and the inner wall 408 of the delivery catheter 102. All or part of the outer surface of the occlusion implant 400 may be coated with Parylene (poly paraxylylene) or any other suitable polymers to reduce the friction coefficient when the occlusion implant 400 is deployed outside of the delivery catheter 102 or retrieved inside of the delivery catheter 102.
One or more radial constraining members 417, 418 are positioned along the braid 410 to restrain the outside dimensions of the braid 410, thereby facilitating and easing the deployment and retrieval of the braid 410 into and out from the delivery catheter 102. A smaller radial dimension of the braid 410 at radially constraining areas 417 and 418 will also reduce braid tension forces between the inner wall 408 of the delivery catheter 102 and the outer surface of each braid segments 411, 412 and 413. Radial constraining members 417 and 418 may also serve as radiopaque markers for a better visualization of the occlusion implant 410 during deployment and retrieval. A distal radiopaque marker 419 and a proximal radiopaque marker 420 provide complete visibility of the implant 410 along its length. Such a braid 410 may include helical coils attached either on the distal end, the proximal end, or on both ends (not shown).
The construing members 406 and 407 in
Occlusion implants of the present invention may be coated internally and/or externally with bioactive agents consisting of a growth factor, a protein, a proteoglycan, a glycosaminoglycan, a physiologically compatible mineral, an antibiotic, a chemotherapeutic agent, a pharmaceutical, an enzyme, a hormone, and genetic material. Alternatively, occlusion implants may include bioactive coatings immobilized on a surface of the occlusion implants. The coating material may include a biotropic ECM (extracellular matrix), with a network of self-assembled collagen fibrils and at least one bioactive agent retained in the ECM material. The coating material may coat the entire surface of the occlusion implant, or any portion thereof, and may comprise one or more individually formed ECM material layers.
Occlusion implants may include material that promotes thrombogenicity including, but not limited to, yarns, fibers, and/or resins, e.g., monofilament yarns, polyester, and the like, as well as other plastic, resin, polymer, woven, fabric surgical materials, shape-memory plastics, and combinations of such materials.
The occlusion implants of the present invention may be introduced into a patient via a catheter inserted into the treatment area to treat parent vessel occlusion or to occlude an aneurysm. At either treatment site, the occlusion implant may be pushed distally out of the catheter and delivered into the parent occlusion site or aneurysm. After being deployed from the catheter, the braided portion of the implant will self-expand into the expanded configuration and assume a pre-set configuration as described above. The deployment of the occlusion implant is always observed under fluoroscopy, and in case the occlusion implant deployment is not satisfactory, the occlusion implant may also be removed or withdrawn (collapsed back into the delivery catheter) and removed outside the body if necessary.
Any of the occlusion implants described in the present invention may be inserted into endovascular and non-endovascular defects, including arteries and veins for parent vessel occlusion or into an aneurysm in order to occlude the aneurysm. The occlusion implant having an expandable braid may have numerous advantages compared to existing therapies such as coils/stents/plugs for shutting the parent vessel or filling aneurysms. The expandable braid would provide many times greater volumetric filing, that may quickly and constantly occlude the artery or divert blood flow from the aneurysm entry, thus reducing the number of coils required per closing of the parent artery or filling of the aneurysm. It may also reduce the risk of aneurysm recanalization, which may allow a patient to avoid taking anti-platelet medications or blood thinners.
The occlusion implant 100 may also be withdrawn and collapsed back into the delivery catheter 700 in case the deployment of the implant 100 into the treatment area 702 is not satisfactory. The placement of the occlusion implant 100 inside the treatment area 702 may be repeated multiple times until the correct position is achieved. When the braid 104 expands inside the treatment area and reaches an expanded configuration 705 and pre-shaped contour, it begins to occupy a greater space within the treatment area 702, providing engagement structure for the helical coil 107 to further fill the treatment space and the promotion of blood clotting. Once the position of the occlusion implant 100 is satisfactory within the treatment location 702, the occlusion implant is disconnected (detached) from the proximal end 109 of the helical coil using the detachment junction 115 as shown in
The configuration of the braid 901 may be formed during fabrication by the braid being woven over a tapered assembly mandrel. Such tapering configuration may taper down from proximal to distal, from distal to proximal, or in any suitable combination of tapering diameters.
The radiopaque component 1007 comprises at least one or more radiopaque helical micro-coils 1009 positioned over a core wire 1010. The micro-coils 1009 may be made of any suitable radiopaque material including but not limited to platinum or gold. The core member 1010 may be made of polymer, metal or metal alloy, including but not limited to suture, SST or Nitinol as a single or multi member unit including wire strands. One or more micro-coils 1009 may be freely placed over the core wire 1010, so it can move along the core wire 1010. The micro-coils 1009 may also be attached to the core wire 1010 using any suitable means, such as glue, crimp, soldering or other means (not shown). In the collapsed position when the braid 1001 is inside the delivery catheter 102, the radiopaque component 1007 assumes a relatively straight configuration (not shown). When the braid 1001 is in the expanded configuration, the radiopaque component 1007 assumes a wavy configuration.
To further increase or improve radiopacity of the braids of the present invention, the Nitinol wires used to make the braids may be made as composite wires with 10-30% platinum.
The occlusion implant 1701 may include a plurality of braids with a variety of different dimensions, including smaller sizes, larger sizes, as well as a variety of cross-sectional configurations including but not limited to circular, non-circular and combination of both (not shown).
The occlusion implant shown and described in
Expandable braids used for the occlusion implants for treatment of defects in humans require several unique characteristics, including but not limited to softness and flexibility, low profile when in the collapsed configuration, and most importantly, ability to be delivered to the treatment locations through a small profile delivery catheter. The braid(s) when delivered through a delivery catheter is in a collapsed configuration that creates radial outward forces and causes a lot of friction between the outside surface of the braid and the inner lumen of the catheter, making such delivery difficult and often time-consuming. One of the known methods in the art to reduce such friction is by providing an inner lumen of the delivery catheter with a polymer having a low friction coefficient, such as Polytetrafluoroethylene (PTFE).
Another method to further reduce such friction is by providing a braid that has as small a braid angle as possible when in the expanded configuration. Such braid with a small expanded braid angle would create lower radial outward forces and consequently less friction when the braid is delivered through the delivery catheter. There are significant technical challenges/limitations to construct a braid made of a small NiTi wire between 0.0005″-0.0010″ at an angle of less than 60 degrees. Often, braids manufactured at angles below 60 degrees are unstable, inconsistent and frequently unreliable.
The present invention provides a braid that is initially made with a primary/first outside diameter and a primary/first braid angle, and then is re-configured to a smaller secondary braid configuration having a secondary outside diameter that is smaller than the original primary/first braid diameter and has a smaller braid angle than the primary braid angle. Such braid modification may be achieved by placing the primary braid over a smaller diameter mandrel and stretching the braid, or collapse-forcing the braid along that mandrel, and fixing both ends to prevent the braid from returning to the original configuration. Fixing the braid ends may be done using a small wire and tightly looping/squeezing both ends of the braid after stretching so the braid will not re-spring to its original configuration. Such prepared braid may then be thermally re-shaped to a new secondary configuration having a smaller outside diameter and smaller braid angle.
The secondary braid angle γ should preferably be less than 60 degrees when in the expanded configuration to further reduce friction within the delivery catheter. The braid 1807 may be made in one of the following patterns: 1 over-1 under wire, 2 over-2 under wires, 1 over-2 under wires, 2 over-2 under wires, and combinations thereof. These braid configurations are well known in the art and will not be described in detail herein. Each pattern has advantages or disadvantages to achieve the braid's ability to open to the expanded configuration when released from a small delivery catheter. However, the 1 over-1 under wire pattern appears to produce the lowest friction resistance when delivered through a delivery catheter while in a collapsed configuration.
The occlusion devices/system 1900 may be comprised of two separate coils: one coil located proximal to the braid, and one located inside the braid (not shown). Such coil(s) may have one of the following configurations: straight, not heat pre-shaped, heat pre-shaped and a combination thereof.
The constraining member 2006 may be pre-shaped by heat to any desired configuration/shape appropriate for treating endovascular and non-endovascular defects. The braid 2001 is suitable to assume a pre-set expanded shape/configuration of the constraining member 2006 when pushed outside the delivery catheter. The braid 2001 and constraining member 2006 may traverse concomitant bends when pushed through and retrieved back into the delivery catheter (not shown). The proximal end 2004 of the braid 2001 is connected to the distal end 2005 of the helical coil 2002 using an intermediate member 2008.
The constraining, member 2006 and the braid 2001 may also both have thermally pre-shaped configurations, and both may assume a similar configuration after release from the delivery catheter. The constraining member 2006 is made of a metal or metal alloy, preferably Nitinol.
While the expandable braid 2101 is anchoring the vessel 2107, deployment of the coil 2102 provides an additional barrier to mitigate forces from blood flow to further slow blood flow and occlude the vessel 2107.
The pusher member 2104 traverses concomitant bends as the delivery catheter 2106 during its delivery to the treatment location inside the vessel 2107. Upon deployment of the occlusion implant 2100 into the vessel 2107, the open-ended braid 2101 expands/opens into an expanded configuration assuming a pre-set shape and anchoring into the wall of the vessel 2107. The helical coil 2102 further fills the space behind the braid 2101.
The occlusion implant 2100 may also be Withdrawn and collapsed back into the delivery catheter 2106 in case the deployment of the implant 2100 into the vessel 2107 is not satisfactory or needs repositioning. The placement of the occlusion implant 2100 inside the vessel 2107 may be repeated multiple times until a correct deployment position is achieved. When the braid 2101 expands inside the vessel 2107 and reaches an expanded configuration and pre-shaped contour, it begins to occupy most of the space inside the vessel 2107, providing an engagement structure for the deployment of the helical coil 2102 and to further mitigate blood pressure on the braid 2101 and facilitating the clotting of blood. Once the occlusion implant 2100 is positioned in the desired location within the vessel 2107, the occlusion implant 2100 is disconnected (detached) from the pusher member 2103 and blood clotting of the vessel 2107 begins.
Alternatively, the occlusion implant 2100 in
Alternatively, the occlusion implant 2300 in
Alternatively, the occlusion implant 2300 in
While the braid shown in the
When the delivery catheter 2306 traverses bends and anatomical curves to access the aneurysm sac 2400, the occlusion implant 2300 in its collapsed configuration traverses concomitant bends as the delivery catheter 2306.
The combination of two dissimilar metals of the occlusion implant 2300, such as the coil 2301 made of Platinum and the braid 2302 made mostly of NiTi alloy, placed in an aqueous environment within the suck of the aneurysm 2400 will create a potential difference between the two metals. The greater the electrical potential between two metals, the more likely a current will be generated. Platinum is one of the lowest in the electro-potential series for metals and as such will be least likely to corrode relative to the other metal such for example NiTi.
The constraining member 2502 may be made of a single wire, multiple wires, strands, coils, tubes, polymer rod, knit, woven, braid and have several configurations suitable to internally support the braid 2501, including but not limited to: straight, tubular, bent, coiled, helical, sinusoidal, wave, closed basket, open basket shaped fingers, open mash, closed mesh or any combination thereof. Such elongate constraining member 2502 may be made of metals, alloys, shape memory material (e.g., Nitinol), cobalt-chromium alloys, Platinum, Platinum-Iridium alloys, polymers (e.g., Nylon, Polyester, etc.). Nitinol with platinum core, or combination thereof.
The constraining member 2502 is extended inside the braid 2501 and may be attached either to the distal attachment area 2503 or to the proximal attachment area 2504, or to both attachment areas 2503 and 2504 as shown in
The elongate constraining member 2502 may also enhance the radiopacity of the MEF device, by virtue of its composition. The constraining member 2502 may also comprise a bioabsorbable material and be dissolved after time.
The constraining member 2502 provides additional internal forces within the braid 2501 to prevent the expanded braid 2501 from squeezing, crushing, collapsing, folding after deployment at the treatment area as shown in
After deployment of the MEF device 2500 inside the sac 2601, blood flow dynamics within the vessel 2600 will cause a pressure from forces created by blood flow and pulsation at the neck of the sac 2601, thereby stressing the braid portions 2602 of the braid 2501 and potentially causing the braid 2501 to experience squeezing, crushing, collapsing or folding. The constraining member 2502 is constructed and designed to prevent, reduce or minimize such deformations by the braid 2501, thereby limiting blood flow from the vessel 2600 into the aneurysm sac 2602 (aneurysm recanalization) and consequently, preventing blood bleeding outside of the aneurysm sac 2601, and preventing aneurysm sac 2601 from rapture and hemorrhagic stroke.
The present invention includes detailed descriptions of braids, and the expandable braids of the present invention include tubular configurations, oval, bulbous, ball-shaped, onion-shaped resembling onion, square, rectangular, irregular/non-symmetrical shapes and any combination thereof. The expandable braid(s) structure may have at least a first braid portion and/or a second braid portion coupled together to helical coils located on the distal end of the braid, between braids or on the proximal end of the braid. The expandable braid of the present invention may also include at least one internal constraining member. The expandable braids may be linearly aligned along the entire implant or may also be out of linear alignment with the implant. The occlusion implants may include helical coils and braids having different outside dimensions and multiple configurations of the constraining member(s). While the present invention describes occlusion implants having one or more components or parts, any combination of these components an any order are incorporated in the present invention as well. Also, reducing some components or parts of the occlusion implants (i.e., removing the coil 2002 in
The number of constraining members in
The occlusion implant devices combining two different metals implanted in the sac of the aneurysm will be in an aqueous-like environment where the platinum component of the coil will be the cathode relative to the anodic NiTi braid/mesh. The electrical potential will generate a localized low current between the two metals. The charge generated will create a charged surface on the material, also known as galvanic corrosion. The presence of two dissimilar metals allows for a more permanent charge on the surface of the metal and would stimulate electro thrombosis long enough for the clot to form and mature. The longer-term dissolution of the anodic material would ultimately contribute to a reduction in mass effect and permit steady shrinkage of larger aneurysms with time.
Alternatively, the surface of the TED and the MEF may be at least partially covered with an external or internal coating to prevent blood from penetrating inside the braid when deployed at the treatment area. Such coating may include but is not limited to coatings previously described, and serve to limit the blood penetration inside the TED/MEF after deployment. Minimizing blood penetration inside the braid may prevent collapsing, deformation or relocation of the braid structure after blood inside the braid forms clots.
The present invention describes devices and methods for treatment of endovascular defects. However, it is intended that the scope of the present invention should not be limited by the particular disease but should include any and all of these devices and methods that are suitable to treat other non-endovascular defects.
Occlusion implants of the present invention are not limited to helically wound coils, and can include random wound coils, coils wound within coils, and braids.
While this specification includes detailed descriptions of expandable braids, the braids of the present invention include tubular configurations, oval, bulbous, ball-shaped, onion-shaped resembling onion, square, rectangular, irregular/non-symmetrical shapes and any combination thereof. The expandable braid(s) structure may have at least a first braid portion and a second braid portion coupled together or to helical coils located on the distal end of the braid, between braids or on the proximal end of the braid. The expandable braids may be linearly aligned along the entire implant or may also be out of linear alignment with the implant. The occlusion implants may include helical coils and braids having different outside dimensions.
Braids of the present invention may also include a woven mesh with variably sized apertures (openings or pores) with a particular porosity or pore density. The expandable braids of the present invention may have sections of mesh or braid having variations in density of the filaments and may include portions or hands of densely spaced filaments (i.e., lower porosity) spaced by portions or bands that are less dense (i.e., higher porosity). The less dense braid portion can have larger openings in the braid, while the denser braid portion can have smaller openings in the braid. The first and second portions of the expandable braid can be discrete structures or can be portion(s) of a unitary or monolithically constructed implant.
Although this invention has been disclosed in the context of certain preferred embodiments and examples, it will be understood by those skilled in the art that the present invention extends beyond the specifically disclosed embodiments to other alternative embodiments and/or uses of the invention and obvious modifications and equivalents thereof. Thus, it is intended that the scope of the present invention herein disclosed should not be limited by the particular disclosed embodiments described above but should be determined only by a fair reading of the claims that follow.
Elements or components shown with any embodiment herein are exemplary for the specific embodiment and may be used on or in combination with other embodiments disclosed herein. The invention is susceptible to various modifications and alternative forms and should not be limited to the particular forms or methods disclosed. To the contrary, the invention is to cover all modifications, equivalents and alternatives thereof.
Some scientific and theoretical considerations have been introduced for assessing how these therapeutic methods and devices are effective; these considerations have been provided for providing an understanding of the invention only and have no relevance to or bearing on claims made to this invention.
This application claims priority from: U.S. Provisional Patent Application No. 62/282,645, filed on Aug. 5, 2015; U.S. Provisional Patent Application No. 62/283,730 filled on Sep. 9, 2015; U.S. Provisional Patent Application No. 62/285,269 filled on Oct. 24, 2015; U.S. patent application Ser. No. 15/227.713 filed on Aug. 3, 2016; U.S. patent application Ser. No. 15/227,735 filed on Aug. 3, 2016 and US Provisional Patent Application No. 62/648,739 filed on Mar. 27, 2018.
| Number | Date | Country | |
|---|---|---|---|
| 62648739 | Mar 2018 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 15227713 | Aug 2016 | US |
| Child | 15947842 | US |
