Claims:We claim:

1. A self-expandable implant (1) for retrieving thrombus from intracranial vessel of patient in need, comprising a plurality of interconnected cells arranged in peripheral rows and coaxially aligned about a longitudinal axis between a proximal (2) and distal (3) end of the implant forming a longitudinally tapered tear drop region (5) at the proximal end and a cylindrical main body (4) extending from the longitudinally tapered tear drop shaped proximal end to the distal end, wherein
said tear drop region consists of four different types of plurality of interconnected cells (5’, 5’’, 5’’’ and 7) arranged in peripheral rows and coaxially aligned around the longitudinal axis, and wherein
said main body (4) of the implant consists of giant (6) and baby cells (7) along the periphery.

2. The self-expandable implant as claimed in claim 1, wherein the tear drop region (5) comprises consecutively, from the proximal end (2), coaxially aligned peripheral rows of first, second, third and fourth plurality of cells (5’, 5’’, 5’’’ and 7) consisting of long leaf, lotus leaf, asymmetric and elliptical shaped cells respectively.

3. The self-expandable implant as claimed in claim 1 or 2, wherein the main body (4) of the implant consists of giant (6) and baby cells (7) along the periphery

4. The self-expandable implant as claimed in claim 1, wherein the giant cells are integrated between two rows of baby cells along the periphery of the main body area of the implant.

5. The self-expandable implant as claimed in claim 4, wherein the giant cells are integrated between two rows of baby cells along the periphery of the main body area (4) of the implant.

6. The self-expandable implant as claimed in claim 5, wherein the placement of giant cells (6) between the rows of baby cells (7) cause to form asymmetric cells (7’) adjacent to the giant cells and in between two consecutive rows of baby cells.

7. The self-expandable implant as claimed in any preceding claim, wherein the cells of the tear drop region have a gradually decreasing length between the said proximal end to the said main body.

8. The self-expandable implant as claimed in any preceding claim, wherein the said tear drop region has a stratified design.

9. The self-expandable implant as claimed in claim 1, wherein the said peripheral rows of plurality of cells are aligned at an angle in respect to the plane transverse to the longitudinal axis of the implant.

10. The self-expandable implant as claimed in claim 1, wherein the said angle at tear drop region is 25° to 30° and more preferably 26° to 28°on one side and 15°to 20° and more preferably 16° to 18° on another side.

11. The self-expandable implant as claimed in any preceding claim, wherein the different cells have the following range of parameters:

Plurality of Cells Length of Cells (mm) Width of Cells (mm) Strut Width (mm) Strut Thickness (mm)
1st Plurality (5’) 5.00-9.00 2.00-3.00 0.08-0.12 0.05-0.08
2nd Plurality (5’’) 4.00-8.00 3.00-4.00 0.08-0.12 0.05-0.08
3rd Plurality (5’’’) 3.00-6.00 2.50-4.50 0.07-0.09 0.05-0.08
4th Plurality or Baby cells (7) 2.50-4.00 2.00-3.50 0.05-0.08 0.05-0.08
Giant Cells (6) 4.00-8.00 5.00-8.00 0.05-0.08 0.05-0.08
Asymmetric Cells (7’) 2.50-5.50 2.00-3.50 0.05-0.08 0.05-0.08

12. The self-expandable implant as claimed in any preceding claim, wherein the different cells have the following parameters:

Plurality of Cells Length of Cells (mm) Width of Cells (mm) Strut Width (mm) Strut Thickness (mm)
1st Plurality (5’) 7.99 2.70 0.090 0.075
2nd Plurality (5’’) 7.11 3.70 0.090 0.075
3rd Plurality (5’’’) 4.65 2.96 0.085 0.075
4th Plurality or Baby cells (7) 3.69 2.94 0.075 0.075
Giant Cells (6) 6.31 6.11 0.075 0.075
Asymmetric Cells (7’) 4.05 2.97 0.075 0.075

13. The self-expandable implant as claimed in claim 1, wherein the said rows are interconnected by joints of different lengths and capable of uniformly transferring radial force to other rows of cells during expansion of the implant.

14. The self-expandable implant as claimed in claim 13, wherein the length of the joints is in the range of 0.07 mm to 0.25 mm.

15. The self-expandable implant as claimed in claim any preceding claim, wherein the tips of said tear drop region cells are provided with radio opaque marker for fluoroscopic vision.
16. The self-expandable implant as claimed in any preceding claim, wherein the tip of said baby cell is provided with radio opaque marker for fluoroscopic vision.

17. The self-expandable implant as claimed in claim 15 or 16, wherein the markers are evenly spaced on periphery of the device.

18. A revascularization device comprising a self-expandable implant as claimed in any preceding claim, the proximal end whereof being attached to a tapered end of a thrust wire.

19. The revascularization device as claimed in claim 17, wherein the said tapered region of wire is provided with radiopaque coil to avoid kinking and improving radiopacity.

20. The revascularization device as claimed in claim 18 or 19, wherein the tapered wire has hydrophilic coating.

21. The revascularization device as claimed in claim 18, wherein fluoroscopic marker is provided at the proximal side of the thrust wire.

22. A micro-catheter assembly for delivering a self-expandable implant for retrieving thrombus from intracranial vessel of patient in need, comprising a micro-catheter and a revascularization device including the self-expandable implant as claimed in any preceding claim.

23. The micro-catheter assembly as claimed in claim 22, wherein the micro-catheter is a tapered microcatheter.

24. A process for manufacturing a self-expandable implant for retrieving thrombus from intracranial vessel of patient in need, comprising the steps of:
- providing nitinol tube;
- laser cutting of nitinol tube;
- descaling;
- heat and shape setting of implant;
- sandblasting on implant;
- electro-polishing of implant; and
- marker attachment.

Dated this 29th day of January, 2019.

(SOUMEN MUKHERJEE)
IN/PA - 214
Applicants’ Agent
for seenergi IPR
, Description:SELF-EXPANDABLE IMPLANT AND REVASCULARIZATION DEVICE CONTAINING THE SAME FOR REMOVING BLOOD CLOT FROM ARTERIES

Field of Invention:
The present invention discloses a self-expandable implant, a revascularization device containing the same as well as a micro-catheter assembly for removing blood clot from the intracranial vessel of cerebral arteries.
The present invention also discloses a method for manufacturing such self-expandable implant and the revascularization device.

Background of the Invention:
Occlusion of the blood capillaries can be caused due to migration of thrombus with the blood circulation (i.e. embolus). The occlusion disrupts blood flow which makes insufficient supply of oxygen and nutrients to brain tissues that lays distally to blood clot which results in tissues death, and patient shows symptoms of stroke. Current invention is related to improve the blood flow by retrieving the thrombus from the intracranial vessel of patient suffered from ischemic stroke and have failed IV t-PA Plasminogen therapy.
Present treatment options available are self-expanding retrievable stents for revascularization of blood vessels.
US 7004954 discloses a device that removes an obstruction from vasculature, comprising an elongate element having a length sufficient to extend from exterior of a patient's body to a treatment site; and a capture device attached to the elongate element, the capture device being coated with a thrombogenic material. The capture device can assume an expanded condition and a contracted condition and is self deploying and wherein it includes knitted super-elastic wire and has a mesh-like structure.
US 20140371779 disclose a clot retrieval device including an elongate member and an expandable clot engaging element configured to extend across the clot in its expanded state. The expandable clot engaging element may include a first monolithic structure and a second monolithic structure. The first monolithic structure may encircle the second monolithic structure over at least a portion of its length. The second monolithic structure may include a proximal section, an intermediate section, and a distal section. The distal section may include an expansion.
US2011184456 discloses devices including a self-expandable member having a proximal end portion and a main body portion. The self-expandable member is movable from a first delivery position to a second placement position, in the first delivery position the expandable member being in an unexpanded position and having a nominal first diameter and in the second position the expandable member being in a radially expanded position and having a second nominal diameter greater than the first nominal diameter for deployment within a vessel or duct of a patient. The expandable member includes a plurality of cell structures with the cell structures in the main body portion extending circumferentially around a longitudinal axis of the expandable member and the cell structures in the proximal end portion extending less than circumferentially around the longitudinal axis of the expandable member to form first and second peripheral rails that vary in width along their lengths.
The devices are expanded across the thrombus which is then supposed to be entangled in the mesh of the stent and which is then removed in a manner similar to the prior system. Again, these devices are futile at treating hard thrombus. In fact, the thrombus is often compressed against the vessel wall by the stent which temporarily opens the vessel by outwardly pressing the clot against the vessel wall. Upon retrieval of the devices, the clot remains or is broken up into several pieces which may emboli to vessels further along the vessel. Thus, there is a requirement for new, easy-to-use, easy to-manufacture, safe surgical devices for removing obstructions such as blood clots from intracranial vessels and carotid arteries.

Objects of the Invention:
The principal object of the present invention is to provide a new, easy-to-use, easy-to-manufacture, safe surgical device for removing obstructions such as blood clots from intracranial vessels and carotid arteries.
It is another of the object of the invention is to provide a self-expandable implant consisting of different types of cells.
It is another object of the present invention is to provide a self-expandable implant consisting of giant and baby cell combinations for better removal of blood clots from intracranial vessels and carotid arteries.
It is yet another object of the present invention is to provide a self-expandable implant consisting of a tapered tear drop zone of different types of plurality of cells.
It is another object of the present invention to provide a revascularization device consisting of a self-expandable implant consisting of different types of cells.
It is a further object of the invention to provide a micro-catheter assembly for using the self-expandable implant and the revascularization device for removal of blood clots from intracranial vessels and carotid arteries.
It is another object of the invention is to provide a process for manufacturing the self-expandable implant as well as the revascularization device.

Summary of the Invention:
Accordingly, the present invention provides a self-expandable implant for retrieving thrombus from intracranial vessel of patient in need, comprising a plurality of interconnected cells arranged in peripheral rows and coaxially aligned about a longitudinal axis between a proximal and distal end of the implant forming a longitudinally tapered tear drop region at the proximal end and a cylindrical main body extending from the longitudinally tapered tear drop shaped proximal end to the distal end, wherein said tear drop region consists of four different types of plurality of interconnected cells arranged in peripheral rows and coaxially aligned around the longitudinal axis, and wherein said main body of the implant consists of giant and baby cells along the periphery.
The tear drop region comprises consecutively, from the proximal end, coaxially aligned peripheral rows of first, second, third and fourth plurality of cells consisting of long leaf, lotus leaf, asymmetric and elliptical shaped cells respectively.
The main body of the implant consists of giant and baby cells along the periphery.
The giant cells are integrated between two rows of baby cells along the periphery of the main body area of the implant. The giant cells are integrated between two rows of baby cells along the periphery of the main body area of the implant.
The placement of giant cells between the rows of baby cells cause to form asymmetric cells adjacent to the giant cells and in between two consecutive rows of baby cells.
The cells of the tear drop region preferably have a gradually decreasing length between the said proximal end to the said main body.
The said tear drop region has a stratified design.
The said peripheral rows of plurality of cells are aligned at an angle in respect to the plane transverse to the longitudinal axis of the implant. The said angle at tear drop region is 25° to 30° and more preferably 26° to 28°on one side and 15°to 20° and more preferably 16° to 18° on another side.
The said rows are interconnected by joints of different lengths and capable of uniformly transferring radial force to other rows of cells during expansion of the implant.
Preferably, the tips of said tear drop region cells are provided with radio opaque marker for fluoroscopic vision.
Preferably, the tip of said baby cell is provided with radio opaque marker for fluoroscopic vision.
The invention also discloses a revascularization device comprising a self-expandable implant as claimed in any preceding claim, the proximal end whereof being attached to a tapered end of a thrust wire.
Preferably the said tapered region of wire is provided with radiopaque coil to avoid kinking and improving radiopacity. Preferably, the tapered wire has hydrophilic coating.
The fluoroscopic marker is provided at the proximal side of the thrust wire.
The invention also provides a micro-catheter assembly for delivering a self-expandable implant for retrieving thrombus from intracranial vessel of patient in need, comprising a micro-catheter and a revascularization device including the self-expandable implant as claimed in any preceding claim. The micro-catheter is a tapered microcatheter.
The invention further provides a process for manufacturing a self-expandable implant for retrieving thrombus from intracranial vessel of patient in need, comprising the steps of: providing nitinol tube; laser cutting of nitinol tube; descaling; heat and shape setting of implant; sandblasting on implant; electro-polishing of implant and marker attachment.

Brief Description of Drawings:
Fig. 1, 1A, 1B, 1C, illustrates the major possibility where thrombus or blood clot can be formed in an artery.
Fig. 2 shows the complete profile of self-expandable implant of the present invention.
Fig. 2A shows the different shapes of the individual cells used in the implant of the present invention.
Fig. 3 shows the main body of the implant of the present invention with giant-baby cell structural design and working region of the implant.
Fig. 4 and 4A show the profile of intersection of adjacent rows connected with each other.
Fig. 5 shows the complete assembly of the delivery thrust wire as used in the present invention.
Fig. 6 and 6A show the connection of the coil marker at the distal end and body marker on the periphery of the self-expandable member.
Fig. 7, 7A and 7B show the possible markers which can be designed for radiopacity on the implant of the present invention,
Fig. 8 illustrates the attachment of the implant with the thrust wire.
Fig. 9 shows the marker which connects the implant with the thrust wire with the help of proximal marker.
Fig. 10 shows the complete assembly of the device with micro-catheter delivery wire, self-expandable implant attached on it. Complete system is introduced in the human to retrieve blood clot.
Fig. 11 is a schematic view of the self-expandable member deployed through the clot.
Fig. 12 illustrates the manufacturing flow chart of the implant of the present invention.

Detailed Description of the Invention:
The present invention discloses a self-expandable implant and revascularization device as well as the micro-catheter assembly capable of being used to remove blood clot from the intracranial vessel of cerebral arteries.
The revascularization device of the present invention comprises delivery thrust wire attached with self-expandable implant.
There are multiple possibilities of forming embolus in the intracranial vessel. Some of the possibilities of thrombus formation are illustrated in Fig. 1 - 1C. In intracranial vessel the maximum possibilities of the clot formation are on the bifurcation of the artery or in the narrower region of the artery.
The implant of the present invention comprises multiple regions like main body region (4), tear drop region (5) and each comprising different types of pluralities of cell (5’, 5’’ and 5’’’) as shown in Fig. 2.
As shown in Fig. 2, the self-expandable implant (1) of the present invention has a plurality of interconnected cells (5’, 5’’, 5’’’ and 7) arranged in peripheral rows and coaxially aligned about a longitudinal axis (A-A) between a proximal (2) and distal end (3) of the implant forming a cylindrical main body (4) structure extending from the distal end (3) up to longitudinally tapered tear drop (5) shaped proximal end (2).

The angle at the tear drop region is varies on both sides for better retrieval i.e. approximately 25° to 30° and more preferably 26° to 28°on one side and 15°to 20° and more preferably 16° to 18° on another side, it has open state stratified design leading to improved expansion of the device with less delivery force or thrust force.
The different shapes of the individual cells are shown in Fig. 2A. As shown in Figs. 2 and 2A, the first plurality of cells (5’) consists of long leaf shaped cell, second plurality of cells (5’’) consists of lotus leaf shaped cells, third plurality of cells (5’’’) consists of asymmetric cells and the fourth plurality of cells (7) consists of elliptical cells, which are also termed interchangeably as baby cells throughout the specification.
It is further shown in Fig. 2A there are one more type of cells called the giant cells (6) used in the implant.
In an embodiment, the tear drop region (5) comprises consecutively, from the proximal end (2), coaxially aligned peripheral rows of first, second, third and fourth plurality of cells (5’, 5’’, 5’’’ and 7) consisting of long leaf, lotus leaf, asymmetric and elliptical shaped cells respectively.
As shown in Fig. 2, the main body (4) of the implant consists of giant (6) and baby cells (7) along the periphery in such a manner that the giant cells are integrated between two rows of baby cells along the periphery of the main body area (4) of the implant. The length of giant cells is such that these can be accommodated in between the two consecutive rows of baby cells. It can also be seen that the placement of giant cells (6) between the rows of baby cells (7) also leads to formation of another set of asymmetric cells (7’) adjacent to the giant cells and in between two consecutive rows of baby cells.
Further as shown in Figs. 2 & 3, the peripheral rows of plurality of cells are aligned at an angle in respect to the plane transverse to the longitudinal axis of the implant.
In another embodiment, the cells may be quadrilateral also. The quadrilateral shaped cells of implant offer clot holding capacity as good as the elliptic or asymmetric shape. However, as the area covered by the elliptic cells is more compared to quadrilateral shape therefore implant with elliptic or asymmetric shape cells, they have more clot holding capacity and are preferred.
The working region of the implant i.e. the main body (4) is aligned with thrombus or clot as shown in Fig. 3. The implant comprises of giant (6) baby (7) cells combination on periphery, which provides better clot holding capacity while baby cells (7) provide better radial strength during expansion.
The implant preferably comprises two types of row joining links (9’, 9’’) as shown in Figs. 4 and 4A. Construction of self-expandable implant and links are such that it uniformly transfers radial force to other rows of cells during expansion.
In an embodiment, the thickness of strut at tear drop region is more than the main body region because it provides strength to expand the stent. The preferred strut thickness at tear drop region is ranges from 0.065mm to 0.090mm, while the thickness of strut at working length is ranges from 0.05mm to 0.08mm and more preferably ranges from 0.05mm to 0.07mm.
As discussed, the self-expandable implant has different pluralities of cells. Smaller cell area and high radial strength are applicable for softer clots while larger cell area and higher radial strength are better for firm white clots. Proximal region of self-expandable implant is longitudinally tapered forming tear drop region. Tear drop region comprises first, second, third and fourth plurality of cells (5’, 5’’, 5’’’ and 7). Tear drop region has the strut width in the ranges from 0.08mm to 0.12mm, more preferably from 0.06mm to 0.09mm and strut thickness ranges from 0.05mm to 0.08mm, more preferably from 0.065mm to 0.080mm. Additionally, thickness at tear drop region may increase to provide better ability of expansion with better radial force for capturing clot.
In a preferred embodiments the cells of the tear drop region has a gradually decreasing length between the said proximal end to the said main body i.e. the length of the cells of first plurality of cells is greater than cells of the second plurality which in turn has a greater length than cells of third plurality and the length of the cells of third plurality is greater than those of fourth plurality.

The various preferred parameter ranges of the cells, such length of the cells, width of the cells, strut width and strut thicknesses are provided in the tabular form in Table 1 below.

Plurality of Cells Length of Cells (mm) Width of Cells (mm) Strut Width (mm) Strut Thickness (mm)
1st Plurality (5’) 5.00-9.00 2.00-3.00 0.08-0.12 0.05-0.08
2nd Plurality (5’’) 4.00-8.00 3.00-4.00 0.08-0.12 0.05-0.08
3rd Plurality (5’’’) 3.00-6.00 2.50-4.50 0.07-0.09 0.05-0.08
4th Plurality or Baby cells (7) 2.50-4.00 2.00-3.50 0.05-0.08 0.05-0.08
Giant Cells (6) 4.00-8.00 5.00-8.00 0.05-0.08 0.05-0.08
Asymmetric Cells (7’) 2.50-5.50 2.00-3.50 0.05-0.08 0.05-0.08

Table: 1

The preferred range of different cell length, width, strut width and thickness of the implant of the present invention is provided in below Table 2.

Plurality of Cells Length of Cells (mm) Width of Cells (mm) Strut Width (mm) Strut Thickness (mm)
1st Plurality (5’) 7.99 2.70 0.090 0.075
2nd Plurality (5’’) 7.11 3.70 0.090 0.075
3rd Plurality (5’’’) 4.65 2.96 0.085 0.075
4th Plurality or Baby cells (7) 3.69 2.94 0.075 0.075
Giant Cells (6) 6.31 6.11 0.075 0.075
Asymmetric Cells (7’) 4.05 2.97 0.075 0.075

Table: 2

In an embodiment, the length and width of the cells of the implant may be kept 2.6mm and 1.8mm leading to high expansion or chronic outward force (COF) and radial outward force (ROF) which may have adverse effect on the vessel wall making the retrieval of the device difficult.
The self-expandable implant (1) of the present invention has larger cells size at the tear drop region compared to main body region. In present invention there are asymmetric cells formed between joining of regular cells which having length ranges from 2.00mm to 6.00mm, more preferably from 3.50mm to 5.50mm and width ranges from 1.80mm to 4.00mm, more preferably from 2.00mm to 3.50mm.
As shown in Fig. 4, 4A, the implant comprises two types of row joining; one is having larger length (9’) ranges from 0.10mm to 0.25mm and 0.15mm to 0.20mm. On the other hand, shorter length (9’’) ranges from 0.07mm to 0.20mm and preferably from 0.13mm to 0.16mm. The design and pattern of links is such that it provides adequate strength and uniform expansion of implant during deployment.
The proximal end (2) of the self-expandable implant has stratified design which leads tread style structure of cells in open state and implant cells mates each other in cylindrical state.
If vessel diameter is less than implant diameter after deployment, diameter of implant will be reduced by under-lapping/ over-lapping leading to increase clot holding capability and retrieval efficiency. If the diameter of vessel and implant is same or bit larger than implant then there is complete expansion of self-expandable implant through the clot and makes clot retrieval easy. At the time of expansion radial outward force and chronic outward force of implant are important.
The implant of the present invention is attached on delivery thrust wire and together they form the revascularization device. As shown in Fig. 5, the revascularization device (13) comprises a tapered delivery thrust wire (13’) which can be made up of stainless steel, nitinol, etc. The wire assembly has tapered region (13’) because implant has to be delivered in intracranial vessel. The tapered region being very thin increases chances of wire kinking, therefore, to avoid kinking radiopaque coil (13’’) is attached over tapered region to improve radiopacity. Preferably the coil is made up of radiopaque material like platinum, gold, tantalum, platinum-iridium, etc. Furthermore, tapered wire has hydrophilic coating which makes smooth and fast insertion of wire through micro-catheter or catheter which leads to reduction in time consumption for minimal invasive surgery.
In an embodiment, as shown in Fig. 9 fluoroscopic marker (14) is provided on proximal end of delivery thrust wire which helps in determining as to when the implant has reached the targeted cerebrovascular region.
In an embodiment, the self-expandable implant has radiopaque markers (10, 12) for visibility under fluoroscopic vision at implant distal end and on periphery of implant as shown in Figs. 6 and 6A. The markers attached are evenly spaced on the periphery of the device. Markers are preferably made up of material like platinum alloy, gold, tantalum, nitinol, platinum-iridium or any other radiopaque materials for better visibility of implant under fluoroscopic vision.
In another embodiment, the complete self-expandable implant is completely coated (10 µm-30µm thickness) with the noble material like gold, silver, etc. through electroplating or spray coating which increases radiopacity as complete implant can be visualized in the fluoroscopic view. Moreover, attachment on self-expandable implant helps in aligning, holding and retrieval of clot.
In another embodiment radiopaque markers are of platinum-iridium material. Diameter of clot can be known by the distance between two markers attached on the periphery of the self-expandable implant. If, clot is soft than the distance between marker remains more; in case of clot is hard than the distance between periphery markers become less.
In yet another embodiment, various kinds of radiopaque markers can be used for radiopacity purpose like coil, coil with tip, simple solid marker, etc. as shown in Figs. 7, 7A and 7B. In present invention coil with tip type radiopaque marker is preferably used as it reduces chance of detaching. All periphery markers are attached in such a way that during retrieval of implant, markers are aligned in one single line and retrieve one after another while crimping or re-sheathing in micro-catheter.
Various techniques can be utilized to attach implant with delivery system like laser welding or adhesive bonding as shown in Fig. 8. In current invention, biocompatible adhesive is preferably used to attach implant with delivery system as laser welding may produce irregular surface resulting in resistance during movement of device in micro-catheter or introducer sheath. Adhesive used to bond implant include any medical grade adhesive such as loctite 4014, dymax 213-CTH, etc. Radiopaque proximal marker is attached on the attachment point of delivery system and implant indicating starting point of implant as shown in Fig. 9. Preferably radiopaque proximal markers are of platinum-iridium material.
As implant is assembled with delivery system, device is ready to use for minimal invasive surgery. In current invention tapered micro-catheter (15) is used for cerebrovascular procedure as shown in Fig. 10. For effective clot trapping implant should be uniformly expand through thrombus or clot as shown in Fig. 11. Afterwards implant is re-sheathed in the catheter once the clot is tangled in implant.
Method of manufacturing of blood flow resurrection device of the present invention is shown in Fig. 12.
The self-expandable implant of the present invention is shown is made through laser cutting on the preformed metal tube by etching process. Metal tube can be made up of Stainless Steel (SS), Cobalt-Chromium (CoCr) or Nitinol (NiTi) alloy. Shape memory and strength of nitinol alloy make material of choice for present invention. The laser cut formed on the tube is in reticulated (mesh) structure as shown in Fig. 2. Alternatively, reticulation structure of present invention may also be manufactured by joining the multitude filament by laser welding process.

Laser Cutting Process:
Laser cutting uses a beam of laser to cut metal materials. Laser cutting works by emerging the output of a high-power laser most commonly through optics. Laser beam involves stimulating a lasing material by electrical discharges or lamps within a closed container. As the self-expandable implant material is stimulated, beam is reflected internally by means of a partial mirror until it achieves sufficient energy to escape as a stream of monochromatic coherent light. Mirrors or fiber optics are typically used to direct coherent light to a lens which focuses light at the work zone.
The implant cutting in the present invention is done on preformed tube and tube diameter ranges from 3.5mm to 6.5mm, more preferably 4.0mm & 6.0mm. Wall thickness of tube ranges from 90micron to 150micron, more preferably 100micron to 110micron. Major parameters which affect laser cutting are laser power, frequency, etc. Oxygen or argon can be used as gas for laser cutting however, oxygen is preferred in present invention as wall thickness is less and argon gas causes weld while cutting process. During laser cutting process oxygen gas pressure ranges from 6.5bar to 11.5bar and more preferably 8.0bar to 9.0bar. Frequency of laser beam ranges from 3.0KHz to 5.0KHz, more preferably 3.5KHz to 4.5KHz and pulse ranges from 0.008ms to 0.015ms. Power of laser may ranges from 58W to 75W, more preferably 60W to 65W. Average power of laser beam ranges from 2.0W to 3.5W, more preferably 2.3W to 2.8W.

Grinding or Descaling Process
After laser cutting process, there are burrs and welds produced on the laser cut tube. To remove welds and burrs either grinding process or descaling process is performed. In present invention, grinding and honing process is performed to make smooth surface finishes inside bores or to hold precise tolerances of bore diameter. Honing produces required surface finish by utilizing an abrasive stone which turns while being moved in and out of work piece. Fluids like glycol, and Alconox® detergent powder by Sigma-Aldrich containing compounds like sodium alkyl-benzene sulfonate, sodium tripolyphosphate and tetra-sodium pyrophosphate (Sigma-Aldrich) are used to provide smooth cutting action and to remove the cut material from bore. It is then cleaned with purified water. The process includes introducing mandrel (tool) into an ID or bore of nitinol tube to remove debris and to change internal surface of tube. A lubricant may be used for easy removal of debris. The material is abrasively removed by the shearing action of the grains contained in the honing tool. This allows inaccuracies of previous operations to be corrected. Roundness is generated by the tool rotation seeking the center line of the diameter of bore. The reciprocating motion of the tool generates straightness. Multiple grits and stages should be used in sizing, if the rough diameter is not within certain limits of the finished requirements. In the present invention, diamond file D-91, D-64 and D-54 are used for grinding purpose. Honing process is done with the help of applying clover gel on rough file with less grit size like D-30, so the implant is free from burrs and welds. Alternatively, descaling process can be used to remove burrs and welds. In descaling process, solution of strong acids such as hydrochloric acid, nitric acid and purified water are mixed in appropriate percentage i.e. 30% mixture of strong acids and 70% purified water and for specific time period. Here we require giving extensive water or detergent washing immediate after acidic descaling process so that the corrosion effect due to acidity gets nullified with water washings.

Shape Setting Process
The use of a nitinol metal for a particular application generally requires the shape setting of metal. The process required to set the shape is similar to beginning with nitinol which may be in the form of wire, strip, sheet, tubing, rod or bar. Shape setting is done by constraining the element on a stainless steel mandrel or fixture of desired shape and applying an appropriate heat treatment.
In general, temperatures range from 460°C to 540°C and more preferably 500°C to 520°C. Time interval for shape setting ranges from 01minute to 15minutes and more preferably from 03minutes to 06minutes. Rapid cooling of some form is preferred via a water, oil or inert gas quench or rapid air cool, in shape setting process. The aluminium oxide powder is allowed to sprinkle on nitinol metal for effective heat treatment during shape setting. The internal grains are improved during the heat-treatment and impart better hardness to internal grains. The stresses are generated in molecular structure during heat treatment which provides permanent required shape to the material. Higher heating will increase the actuation temperature of the part and often gives a sharp thermal response. However, there is usually a concurrent drop either in peak force produced in the shape memory of nitinol. Due to such increment, there is decrease in the ability of nitinol element to resist permanent deformation. Care should be taken for heat treatment fixtures that can be surprisingly sluggish in reaching the desired temperature in air or vacuum furnaces. To achieve desire shape, heating a metal to a specific temperature and cooling at a specified rate will produce a refined microstructure either fully or partially separating constituents. Therefore, for proper shape and stress relieving of implant is given for desired shape setting or stress relieving.
In present invention, set fluidized bath parameter such as temperature ranges from 460°C-540°C and more preferably 500°C-520°C according to ASTM F-2063. In preferred embodiment mandrels are placed in the fluidized bath for time period ranging from 5-10 minutes and further mandrels are immediately quenched in water tank to produce a martensite transformation of the implant structure. Martensitic transformation is the name for any transformation that takes place in diffusion-in fewer manners that is, these transformations take place through atomic movements which are less than an atomic spacing and in these transformations atoms change their positions in a coordinated manner. In shape memory alloys such as Ni-Ti (nitinol), it is the martensitic transformation that is responsible for the shape memory effect.

Sand Blasting Process
Sand blasting is performed to provide highly smooth surface. Devices such as stents, shunts and cages, etc. are commonly blasted to form smooth surface, remove oxide layers from surface, and remove pulse marks and striations left by laser machining. Further sand blasting cut or remove laser slag, decrease propensity for micro-cracking and lightly texture the surface for improving adhesion characteristics. Aluminium oxide powder is sprayed on the surface at certain velocity. The pressure exertion of the powder varies from 20psi to 90psi, preferably from 30psi to 60psi and more preferably 40psi to 50psi. Highly smooth and shiny surface with increase in surface texture of the nitinol is achieved after sandblasting process.

Electro-polishing Process
After sand blasting process, there is formation of oxides layer on surface, sharp edges and other impurity. For removal of micro burrs, welds and sharp edges electro-polishing process is performed. In electro-polishing process electrolyte are used which include acids with high viscosity, such as sulphuric acid and phosphoric acid. Mixture of electrolytes is perchlorates with acetic anhydride and methanolic solution of sulphuric acid. More preferably sulphuric acid and phosphoric acid are used as mixture. In a beaker mixture is added and copper plates are attached as cathode. Further, implant to be polished is attached as anode with appropriate voltage and current. Voltage ranges from 7-12Volts but more preferably 5-12Volts. The self-expandable implant is kept for specific time period and observed under microscope and same cycle is followed until implant is polished. Each cycle time ranges from 02minutes to 05minutes and number of cycle ranges from 02 to 06. In present invention, electro-polishing is performed as 03 cycles of 01minute at 9V and 0.9A.

Radiopaque Marker Attachment
Radiopaque markers are attached on implant by laser welding technique or bonding technique as shown in Fig. 7, 7A and 7B. Hollow cylindrical shape marker with close end with semi-circle as shown in Fig. 7A and marker with only coil can be attached by providing a hole at the end of the cells as shown in Fig. 7B. Generally, length and diameter of marker ranges between 0.8mm to 0.12mm and 0.3mm to 0.7mm respectively. Preferably, the markers utilized are coil-tip markers. The length and diameter of coil tip marker ranges from 0.50mm to 1.00mm and 0.25mm to 0.60mm respectively. Adhesive used to bond marker on implant include any medical grade adhesive like loctite 4014, dymax 213CTH, etc. The radiopaque proximal marker is attached on the attachment point of delivery system and implant which indicates starting point of implant. The attachment of marker is done by placing implant under the microscope and with the help of appropriate holding apparatus i.e. forceps for holding marker and attaching with the help of glue containing polyurethane that is a UV curing adhesive and attachment is accomplished by UV curing process.

Delivery System Attachment
In present invention delivery system is made of nitinol tapered wire and radiopaque coil which has been attached on tapered wire with the help of adhesive or laser welding as shown in Fig. 9. Heat shrink tube is shrunk at distal end of tapered wire. Length of heat shrink tube ranges from 430mm to 450mm. Purpose of heat shrink tube is to provide lubricity and strength to the tapered region. Heat shrink tube used can be PTFE, grilamid, etc. Self-expandable member is attached on the delivery system which is tapered wire and radiopaque coil is assembled on the tapered region of the delivery thrust wire by laser welding or with adhesives. The delivery thrust wire has provision of fluorosafe marker which is 100cm from the distal end of the delivery wire which is uncoated with hydrophilic coating. In one embodiment attachment is done by adhesive bonding. The attachment of implant on delivery system is done under the microscope. Same adhesive is used for attachment of the implant on the delivery system as done for the attachment of body and distal marker. Adhesive used is same as the substrate to be attached are same as the proximal marker is platinum-iridium to be attached on the connection of the delivery system of nitinol and implant which is also nitinol.

Sterilization & Packaging
After finished product is completed killing of micro-organism and making device free from impurities sterilization process is done. 100% ethylene oxide one time use cartridge is used for sterilization of the implant. Device is packed in vacuum sealed tyvek pouch as primary packaging. Temperature should be less than or equal to 24°C at work place. Relative humidity must be less than or equal to 55% at work place. The process is performed in surrounding area of class 1,00,000. Sterilization is performed at 42 ± 3°C temperature, relative humidity (%RH) less than or equal to 40%, Vacuum pressure set point less than 160mbar, aeration time 180minutes and exposure time 120minutes.
The present invention is described based on some preferred embodiment. Several modifications of the invention may be possible without departing from the scope of invention as described in the preceding description and the appended claims.