Title of Invention

A DILATION DEVICE AND A METHOD OF CONSTRUCTING THE SAME

Abstract

A dilation device (1) to dilate the contracted biliary tract, ureter and blood vessel etc. made-up of a wire or a strip (2) primarily comprising set of segments (3) and two opposite atraumatic ends (4, 5), and each such segment (3) comprising set of loop structures (6, 11, 12), having one open end (7), another closed end (8) and two arms (9 and 10) is provided. A method of constructing the dilation device comprising steps of turning the wire or strip (2) to form loop structures (6, 11, 12) which form a segment (3) and continuous to form next segment (3) of such loop structures (6, 11, 12) by turning one of the two arms (10) of last loop structure (12) of previous segment (3) to opposite side and continuous as inter-connector part (14), which is turned back onto itself to form loop structures (6, 11, 12) of next segment (3) is also provided.

Full Text

NVENTORS: The present invention is by Dr. Bhupathi Raju Soma Raju, Chairman, CAR±, Hospital, The Heart Institute, Exhibition Road, Nampally, Hyderabad-5 00001; Dr. Aramadaka Venugopal Reddy, Scientist-F, Defence Matellurgical Research Laboratory (DMRL), Defence Research & Development Organisation (DRDO), Kanchanbagh PO, Hyderabad-500058; Arun Tiwari, Programme Manager, Society for Bio-medical Technology (SBMT), DEBEL Technology Cell, DRDL Campus, Kanchanbagh, Hyderabad-500268, presently Director, Cardiovascular Technology Institute, CARE Foundation, NIMS Lane, Road No. 1, Banjara Hills, Hyderabad-500034; and Dr. N. Krishna Reddy, CARE Hospital, The Heart Institute, Exhibition Road, Nampally, Hyderabad-500001, India, all Indian Nationals. FIELD OF THE INVENTION : The present invention relates to a dilation device, particularly to a wire form dilation device. The present invention relates to a dilation device for dilating the biliary tract, ureter and blood vessel etc. and to maintain the patency thereof, and of the method of constructing the same. BACKGROUND OF THE INVENTION : The body parts of the human beings, such as biliary tract, ureter, urethra, artery, gastrointestinal tract etc. on contraction due to medical disease, as known in the art, hinder the free flow of the liquid part through such body parts. Such defects in the said body parts demand the surgery, which in turn may necessitate the implantation of the device to expand the contracted part of the said body part. Such implanted device, as stated above, is required to provide the support to the expanded body wall of the said body part while maintaining the expansion of the said body part and to maintain the patency of the said body part. Such requirements of the dilation device for dilating and of maintaining the dilation of the said body part in addition to supporting the walls of the dilated part of the said defected body parts can be met only if the said dilation device meet the requirement of expansion, particularly uniform expansion, more particularly of radial uniform expansion at the targeted site and of the mechanical requirements, like the strength and balance between the rigidity and flexibility, in addition to other properties, like flexibility, non-thrombogenecity, radio-opacity. The more rigid structure of such dilation devices will effect the movement of the said device during implantation, particularly through the bend parts of the said body parts. On the other more flexible structure of such dilation devices will not be able to support the dilated part of the said body part. The non-uniform expansion of such dilation devices will result in non-uniform dilation of the contracted part of the said body part, and hence will not overcome the defect fully, and intum may not serve the basic purpose of implanted device, hence making the surgery a failure. To meet the requirement of dilating the body lumens, certain dilation devices are known in the prior art. The known dilation devices may have a compression spring structure or a mechanically rotating structure. The compression spring structured dilation devices as known in the prior art have major drawback of having the fixed expanded diameter, hence may not expand to the inner diameter of the body lumens/vessel wherein it is implanted, which inturn may result in the possibility of thrombosis. The mechanically rotating dilation devices, which can overcome the drawback of fixed and limited expansion and can achieve the maximum desired dimension on expansion, but may result in blood coagulation and possible thrombosis and still involve the complexity of the procedure. Another disadvantage of such known mechanically rotating dilation devices is that, the desired expansion/dilation of the known such devices is some times achieved after implantation by using the external heat source, the use of which it self is complex procedure and further complicates the post-operative/post-surgery procedure. Further major drawbacks of using the external heat source are the drawbacks of blood coagulation and possible thrombosis. The dilation devices, as known in the prior art may also cause the restenosis, which in turn may result in the need of second surgery. The dilation devices as known in the prior art generally may have poor, particularly nonuniform radial strength. Therefore, the known such devices collapse and return back to the unexpanded form and hence result in the recollapse of the expanded/dilated lumen or vessel wherein the said device has been implanted. Hence, such known dilation devices are unable to support, particularly are unable to provide the mechanical support to the expanded wall of the lumens vessel wherein the said device has been implanted. Other such known devices are of tubular shape which also suffer generally from the drawback of being stiff and stable enough radially, particularly being radially rigid. Still further known dilation devices of prior art are particularly pre-mounted on to the transportation device which is generally an expandable balloon made up of a polymeric material. Such known pre-mounted dilation devices have major drawback that they are made specific to the said transportation device, hence restricting their wider applications. Still another drawback of such known pre-mounted dilation devices is that, the wire form dilation device may be drawn directly on to the said transportation device, which further restrict their wider applications. Known such wire form dilation devices generally have open ended wire, which on expansion after implantation at the targeted site of the selected lumen or vessel may cause damage to the said lumen or vessel wall, like it may puncture the wall. Further such pre-mounted dialtion devices may suffer from coil disruption and separation drawbacks. The known wire-form dilation devices maintain their longitudinal flexibility through interconnectors between the two adjacent segments of the said dilation device, and the said interconnectors are generally welded. The major drawback of such known dilation devices having said interconnectors or welded parts is their higher rigidit structure, which inturn will result in various other disadvantages as described herein above, of rigid structure, particularly problems of increased restenosis at the implantation site. NEED OF THE INVENTION : Therefore, there is a need to have an improved dilation device, particularly an improved wire-form dialtion device, which can overcome the disadvantages of the prior art as described herein above. OBJECTS OF THE INVENTION : The main object of the present invention is to make a complete discloser of a dilation device for serving both the requirements of such device, that is, first to dilate the contracted lumen or vessel and then to maintain the dilation of the dilated lumen or vessel at the same time supporting the dilated walls of the said lumen or vessel. The another object of the presently disclosed invention is to propose for a dilation device which can be implanted at any desired target, particularly at the selected site, using any standard transportation device, that is, catheter and balloon assembly, and standard implantation procedure. Still another object of the presently disclosed invention is to propose for a dilation device which can be expanded only after it is implanted at the desired site of the selected lumen or vessel, and expands to the diameter just equal to the inner diameter of the fully dilated lumen or vessel, wherein said device has been implanted. Therefore, presently disclosed dilation device has advantages of dilating the collapsed part of the said lumen or vessel, and indefinitely supporting the dilated part to avoid the recollapse of the said lumen or vessel. Still further an object of this invention is to disclose a dilation device, which can be crimped on to the desired transportation device having any diameter, hence making it suitable for all types of transportation devices, which inturn makes the proposed device more widely acceptable. This is still further an object of this invention to propose for a dilation device having a structure, which has capability of uniform expansion, particularly capability of uniformly radial expansion. Yet another an object of this invention is to make a disclosure of a dilation device having atraumatic ends, which inturn do not cause any damage to the wall of the lumen or vessel wherein the said device has been implanted. This is yet another an object of the present invention to make a disclosure of a dilation device having no interconnectors or welded parts between the two adjacent segments of the said device. The absence of such interconnectors or welded parts makes the proposed device convenient to manufacture and at the same time results in the device having balance in the rigidity and flexibility characteristics. The presently disclosed dilation device has another advantages of having flexibility and better radial strength with no spring action and still being universal in application. Still further an advantage of presently disclosed device is that it does not has pre-mounting requirement. BRIEF OF THE INVENTION : Accordingly the present invention provides the complete disclosure of a dilation device, which can be implanted at any selected site of any selected lumen or vessel using any transportation means, that is balloon of any diameter. The proposed device is suitable for dilating and as well as for opening the obstructions, such as coronary obstruction, and has the resistance to collapse and can withstand the continous stresses of the beating heart. The presently disclosed dilation device is devoid of any spring action and capable of maintaining the cylindrical configuration before and after expansion, hence can serve as a ermanent prosthesis, the foremost requirement of any implant, particularly of any unresolvable implant, which is expected to stay in the body permanently. As the structure of the proposed dilation device is devoid of any fixed or welded interconnector and do not has the fixed diameter, therefore the proposed dilation device do not create a turbulant flow of fluid, particularly of blood. The presently disclosed invention also makes disclosure about the method of construction of the proposed dilation device, which inturn is economical and convenient to manufacture. In accordance to the presently disclosed invention the dilation device as disclosed herein, is made-up of a wire, primarily comprising of set of segments, interconnected through the continous wire, wherein each such segment comprises of hair pin type loop structures having one open end, another closed end and two arms, and one of two such arms of said loop structure of said segment is the extension of the previous such segment and another arm of said loop structure of said segment continous into the another loop structure of same said segment and so on till it forms the desired number of said loop structures of said segment, by turning the said wire in a manner to result in various loop structures, preferably three, having their open ends on the same side only, and then continous to form next segment of such loop structures. The continuity is maintained from one segment of set of hair pin type loop structures to another such segment without any interconnector, particularly without any welded part/interconnector. The opposite ends of the wire forming the dilation device in accordance to the preferred embodiments of the present invention are rounded onto themselves. The other preferred embodiments and the advantages of the presently disclosed dilation device will become more apparant, when this specification is read with the accompanying figures, which are not intended to limit the scope of this invention. DESCRIPTION OF THE FIGURES : Figure-1 shows a longitudinal side view of the unexpanded dilation device in accordance to one of the preferred embodiments of the present invention. Figure-2 shows a longitudinal side view of the semi-expanded dilation device in accordance to one of the preferred embodiments of the present invention. Figure-3 shows a longitudinal side view of the fully expanded dilation device in accordance to one of the preferred embodiments of the present invention. Figure-4 shows a schematic diagram of the construction of loop (figure 4A), of a segment (figure 4B) and of atraumatic ends (figure 4C) of the presently disclosed dilation device in accordance to the preferred embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION: Accordingly, the present invention makes a complete disclosure of a dilation device, particularly of a wire-form dilation device to dilate the biliary tract, ureter and blood vessel etc. and to maintain the patency thereof, and of the method of constructing the same. Now referring to the preferred embodiment of the presently disclosed invention and the enclosed figures, the dilation device (1) is essentially made-up of a wire or a strip (2), preferably of the metallic wire and primarily comprises of set of segments (3) and two opposite atraumatic ends (4 and 5), wherein each such segment (3) comprises of set of loop structures (6), preferably hair pin type loop structures, having one open end (7), another closed end (8) and two arms (9 and 10), which may also be referred as legs or sides of the said loop structure (6), and one arm (9) of two such arms (9 and 10) of said loop structure (6) of said segment (3) is the extension of the previous such segment (3) or of the end (4), as the case may be, and another arm (10) of said loop structure (6) of said segment (3) continous into arm (9) of the another loop structure (11) of same said segment (3). The arm (10) of this loop structure (11) continous into arm (9) of still another similar loop structure (12) and so on till it forms the desired number of said loop structures (6, 11 and 12) of said segment (3) by turning the said wire (2) in a manner to result in various such loop structures (6, 11, 12), then continous to form next segment (3) of such loop structures (6,11,12). The next segment (3) of such loop structures (6, 11, 12) of presently disclosed dilation device is formed by turning arm (10) of the last loop structure (12) of segment (3) at part 13 to the opposite side and continous as interconnector part 14 to form another similar segment (3) comprising preferably of the same number of loop structures (6, 11, 12), which in turn are constructed preferably in the similar fashion, as described herein above. The wire (2) coming from previous segment (3) or from the atraumatic end (4) is turned in the similar manner, that is turns back onto itself at part (15) every time on the same side only to result in various loop structures (6, 11, 12) in each segment structure (3). The number of such loop structures (6) in each segment (3) may varry from any number to any number, preferably there are three number of such loop structures (6, 11 and 12) in each segment (3). The ends (8) of each loop strocture (6, 11, 12) of each segment structure (3) are preferably of rounded shape. Further, in accordance to preferred embodiment of the present invention, the continuity of the presently disclosed dilation device (1) is maintained from one segment (3) of set of hair pin type loop structures (6, 11, 12) to another such segment (3) of similar loop structures (6, 11, 12) without tny welded part or welded interconnector and it is continuation of the same wire (2) througn *nterconnector part 14 of said wire (2), as described herein above. According to the preferred embodiment of the present invention the continous interconnected (14) are preferably constructed on the same side, which remain on the same side even when the device (1) is expanded, as shown in figure-3. However, such arrangement does not limit the scope of the present invention. In accordance to the preferred embodiment of the presently disclosed invention the open ends (7) of each loop structure (6, 11, 12) of same segment (3) are essentially on the same side, as indicated by arrows 17 and such indications are merely for understanding. The construction of the loop (6 or 11 or 12) is shown in figure 4A. Each loop comprises of one open end part 7, another closed end part 8 and two arms 9 and 10, as described herein above, and said arms 9 and 10 are constructed at certain distance 18, and part 19 connects said arms 9 and 10, and form said closed end 8. The distance 18 between arms 9 and 10 need not be same in each loop structure (6 or 11 or 12). The construction of a segment (3) is shown in figure 4B. This figure shows the segment (3) in its open state. The open ends (7) are on the same side, as shown by arrows 17. Similarly the closed ends (8) are on same side, as shown by arrows 20. The gap 21 between two adjacent segments (3) may varry. The opposite ends (4 and 5) of the wire (2) forming the dilation device (1), in accordance to the preferred embodiment of the present invention, are essentially rounded onto themselves and are preferably welded to avoid any free floating end of the wire (2), as shown in figure 4C, which in turn completely neglects the chances of any injury or damage to the wall of the body lumen or the vessel. The arrows (16) as shown in each figure (Figure-1, 2 and 3) are indicating the direction of movement of the wire (2) of the dilation device (1), while constructing the presently disclosed device (1). The number of segments (3) in each dilation device (1) may vary from any number to any number preferably there are three or more such segments in a device. The number of segments (3) is determined by the desired length of the dilation device (1). The present invention has been described with reference of a segment structure (3) having preferably three loop structures (6, 11, 12), however the number of loop structures can also vary to meet the requirement of the desired diameter of the body lumen or vessel, wherein the said dilation device is required to be implanted. In accordance to the preferred embodiment of the present invention the diameter of the presently disclosed dilation device (1) is controlled by number of such loop structures (6, 11, 12) and by distance (18) between the said arms (9 and 10) of such loop structures (6,11, 12). The present invention has been described with the help of accompanying drawings, whicn are not intended to limit the scope of the present invention. The number of loops per segment, number of segments per device, the length of arms of a loop, distance between arms of a loop, distance between adjacent segments and relationship between loop-to-loop of same segment may be altered to get desired dilation device without deviating from the scope of the present invention. In the foregoing description and accompanying figures the repetitive segments (3) and loop structures thereof (6, 11, 12) of said dilation device (1) have been given same numbers merely for better understanding. The loop structures (6,11 and 12) of one of the many segments (3) have been indicated by shading in accompanied figures merely for better understanding of constructional features of said loop structures (6,11,12). The direction (16) of turning of wire (2) is also merely as an indicator of manner of construction of said device. Such direction (16) indicator may start from another end (5) as well. Therefore such indicators, given for better understanding of the constructional features of the device of the present invention are not intended to limit the scope of the presently disclosed invention. Further, it is obvious to persons working in this area, that various modifications of the presently disclosed device are possible without deviating the scope of this invention. CLAIM: 1. A dilation device, particularly a wire-form dilation device to dilate the contracted biliary tract, ureter and blood vessel etc., to maintain the dilation and to support the dilated walls of the said dilated lumen or vessel, wherein said dilation device (1) made-up of a wire or a strip (2) primarily comprises of set of segments (3) and two opposite atraumatic ends (4 and 5), and each such segment (3) comprises of set of loop structures (6), having one open end (7), another closed end (8) and two arms (9 and 10), and method of constructing thereof. 2. A dilation device, as claimed in claim 1, wherein one arm (9) of said two arms (9 and 10) of said loop structure (6) of said segment (3) is the extension of the previous such segment (3) or of said end (4), and another arm (10) of said loop structure (6) of said segment (3) continous into arm (9) of the another loop structure (11) of said same segment (3). 3. A dilation device, as claimed in claims 1 and 2, wherein arm (10) of said another loop structure (11) continous into arm (9) of still another similar loop structure (12) and so on till it forms the desired number of said loop structures (6,11 and 12) of said segment (3). 4. A dilation device, as claimed in claims 1 to 3, wherein said loop structures (6, 11, 12) are constructed by turning said wire (2) in a manner to result in various such loop structures (6,11, 12), then continous to form next segment (3) of such loop structures (6,11,12). 5. A dilation device, as claimed in preceeding claims, wherein said various loop structures (6, 11, 12), may varry from two to any number, preferably three in number, in said each segment (3). 6. A dilation device, as claimed in claim 1, wherein said loop structures (6) are preferably of hair pin type structures. 7. A dilation device, as claimed in preceeding claims, wherein said closed ends (8) of said loop stroctures (6,11,12) of said segment structures (3) are preferably of rounded shape. 8. A dilation device, as claimed in preceeding claims, wherein said open ends (7) of said loop structures (6,11,12) of said same segments (3) are essentially on the same side, 9. A dilation device, as claimed in preceeding claims, wherein said arms 9 and 10 are constructed at certain distance 18, and part 19 connects said arms 9 and 10, and form said closed end 8. 10. A dilation device, as claimed in preceeding claims, wherein said segments (3) comprise preferably of same number of said loop structures (6, 11, 12) constructed preferably in similar fashion. 11. A dilation device, as claimed in preceeding claims, wherein said next segment (3) of said such loop structures (6, 11, 12) is formed by turning arm (10) of last loop structure (12) of previous segment (3) at part 13 to the opposite side and continous as interconnector part 14. 2. A dilation device, as claimed in preceeding claims, wherein said interconnector part (14) of said wire (2) coming from said previous segment (3) or from said atraumatic end (4) turns back onto itself at part (15) every time on the same side only to form said loop structures (6, 11 12) of said next segment (3). 13. A dilation device, as claimed in preceeding claims, wherein said continous interconnectors (14) are preferably constructed on the same side of said segments (3) of said dilation device (1). 14. A dilation device, as claimed in preceeding claims, wherein said continuity of said dilation device (1) is maintained from said one segment (3) of said set of said loop structures (6,11,12) to said next segment (3) of said similar loop structures (6, 11, 12) without any welded part or welded interconnector. 15. A dilation device, as claimed in preceeding claims, wherein said opposite ends (4 and 5) of said wire (2) forming said dilation device (1) are essentially rounded onto themselves and are preferably welded. 16. A dilation device, as claimed in preceeding claims, wherein said number of said segments (3) may vary from any number to any number, preferably three or more. 17. A dilation device and method of construction thereof, as claimed in preceeding claims and described herein above with accompanied figures.

Documents:

772-mas-1997-abstract.pdf

772-mas-1997-claims duplicate.pdf

772-mas-1997-claims original.pdf

772-mas-1997-correspondance others.pdf

772-mas-1997-correspondance po.pdf

772-mas-1997-description complete duplicate.pdf

772-mas-1997-description complete original.pdf

772-mas-1997-description provisional.pdf

772-mas-1997-drawings.pdf

772-mas-1997-form 1.pdf

772-mas-1997-form 13.pdf

772-mas-1997-form 26.pdf

772-mas-1997-form 3.pdf