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US-20260124052-A1 - DEVICE AND METHOD OF RADIALLY COLLAPSING MEDICAL DEVICES

US20260124052A1US 20260124052 A1US20260124052 A1US 20260124052A1US-20260124052-A1

Abstract

A device and method of radially collapsing a medical device is disclosed. The device is in the form of an improved crimper which is capable of crimping a medical device. The crimper includes without limitation one or more of, a base plate, a stopper, two side plates, two housing plates with a handle, a plurality of jaws, two guide plates, at least one gear ring and a plurality of gear pins. The jaws, when assembled, collectively form an iris opening. The assembly of the crimper has a central opening through which the iris opening can be accessed. The device to be crimped is introduced in the central opening and held within the iris opening. The crimping is achieved by reducing the size of the iris opening (by moving the jaws simultaneously with respect to each other in synchronized manner) which in turn reduces the diameter of the prosthetic device.

Inventors

  • Harshad Amrutlal PARMAR
  • CHIRAG VINODBHAI PATEL

Assignees

  • MERIL LIFE SCIENCES PVT LTD.

Dates

Publication Date
20260507
Application Date
20251222
Priority Date
20211112

Claims (13)

  1. 1 . A crimping device ( 100 ) for crimping a prosthetic device, the crimping device ( 100 ) comprising: a handle ( 109 ) configured to move upwards and downwards; at least one gear ring ( 115 ) and configured to rotate in response to the movement of the handle ( 109 ), the at least one gear ring ( 115 ) comprising threads ( 115 a ); a guide housing disposed within an inner circumference of the at least one gear ring ( 115 ); a plurality of jaws ( 111 ) disposed within the guide housing and movable linearly in a radial direction within the guide housing, each jaw ( 111 ) comprising: a top surface ( 111 e ); a tapered surface ( 111 d ); and a hole ( 111 c ) provided in the top surface ( 111 e ) of the jaw ( 111 ), the hole ( 111 c ) having internal threads; wherein the tapered surfaces ( 111 d ) of the plurality of jaws ( 111 ) when assembled form an iris opening ( 111 a ) configured to receive a prosthetic device; and a plurality of gear pins ( 117 ), each gear pin ( 117 ) comprising a head portion ( 117 a ) having external threads configured to mate with the threads ( 115 a ) of the gear ring ( 115 ), and a threaded pin portion ( 117 b ) having threads ( 117 c ) configured to mate with the threads in the hole ( 111 c ) of a corresponding jaw ( 111 ); wherein in response to the movement of the handle ( 109 ), the at least one gear ring ( 115 ) and the plurality of gear pins ( 117 ) rotate, causing the plurality of jaws ( 111 ) to move linearly in a radial direction, thereby changing the size of the iris opening ( 111 a ).
  2. 2 . The crimping device ( 100 ) as claimed in claim 1 , wherein the crimping device ( 100 ) further comprises two housing plates ( 107 , 107 ′), each housing plate ( 107 , 107 ′) having a handle portion ( 107 b ) and a tray portion with a central housing opening ( 107 c ), wherein when the two housing plates ( 107 , 107 ′) are assembled, the tray portions of the housing plates ( 107 , 107 ′) form a housing ( 107 A) to accommodate the at least one gear ring ( 115 ), the guide plates ( 113 , 113 ′), the plurality of jaws ( 111 ) and the plurality of gear pins ( 117 ) and the handle portions ( 107 b ) form the handle ( 109 ).
  3. 3 . The crimping device ( 100 ) as claimed in claim 2 , wherein each housing plate ( 107 , 107 ′) has a raised edge (e 1 ), wherein the at least one gear ring ( 115 ) has an outer diameter that is smaller than the internal diameter of the raised edge (e 1 ) of the housing plates ( 107 , 107 ′).
  4. 4 . The crimping device ( 100 ) as claimed in claim 2 , wherein one of: the at least one gear ring ( 115 ) comprises one gear ring ( 115 ) fixed into one of the housing plates ( 107 , 107 ′) such that the gear ring ( 115 ) is free to rotate relative to the housing plate ( 107 , 107 ′) while the other housing plate ( 107 , 107 ′) does not have a gear ring ( 115 ), or the at least one gear ring ( 115 ) comprises one gear ring ( 115 ) firmly fixed into one of the housing plates ( 107 , 107 ′) while the other housing plate ( 107 , 107 ′) does not have a gear ring ( 115 ), or the at least one gear ring ( 115 ) comprises two gear rings ( 115 ), wherein one of the two gear rings ( 115 ) is fixed in one of the housing plates ( 107 , 107 ′) such that the gear ring ( 115 ) is free to rotate relative to the housing plate ( 107 , 107 ′) while the other gear ring ( 115 ) is firmly fixed in the other housing plate ( 107 , 107 ′), or the at least one gear ring ( 115 ) comprises two gear rings ( 115 ), wherein one gear ring ( 115 ) is firmly fixed in each of the housing plates ( 107 , 107 ′).
  5. 5 . The crimping device ( 100 ) as claimed in any of the above claims , wherein the crimping device ( 100 ) comprises two side plates ( 105 , 105 ′), each side plate ( 105 , 105 ′) coupled with a corresponding housing plate ( 107 , 107 ′) such that the two housing plates ( 107 , 107 ′) are free to rotate relative to the side plates ( 105 , 105 ′).
  6. 6 . The crimping device ( 100 ) as claimed in claim 5 , wherein the crimping device ( 100 ) comprises a base plate ( 101 ) coupled with the side plates ( 105 , 105 ′).
  7. 7 . The crimping device ( 100 ) as claimed in any of the above claims , wherein the crimping device ( 100 ) comprises two guide plates ( 113 , 113 ′) forming the guiding housing, each guide plate ( 113 , 113 ′) comprising a central guide opening ( 113 b ) and a plurality of linear guides ( 113 a ) extending away from a central portion of the guide plate ( 113 , 113 ′) in a radial direction; wherein a groove ( 111 b , 111 b ′) is provided on each of two sides of the jaw ( 111 ), each groove ( 111 b , 111 b ′) engaging with a corresponding linear guide ( 113 a ) of the guide plates ( 113 , 113 ′), wherein the rotation of the plurality of gear pins ( 117 ) causes the plurality of jaws ( 111 ) slide over the linear guides ( 113 a ).
  8. 8 . The crimping device ( 100 ) as claimed in claim 7 , wherein one of: the guide plates ( 113 , 113 ′) include a raised guide edge ( 113 d ) having a circular round shape outer periphery with an outer diameter that is smaller than an internal diameter of the gear ring ( 115 ), or the guide plates ( 113 , 113 ′) include a raised guide edge ( 113 d ) having a polygonal shape outer periphery with an outer dimension smaller than an internal diameter of the gear ring ( 115 ).
  9. 9 . The crimping device ( 100 ) as claimed in any of the above claims , wherein the head portion ( 117 a ) of each gear pin ( 117 ) has a diameter that is larger than a diameter of the pin portion ( 117 b ) of the gear pin ( 117 ).
  10. 10 . The crimping device ( 100 ) as claimed in any of the above claims , wherein the crimping device ( 100 ) comprises one or more stoppers ( 103 ) configured to restrict the downward movement of the handle ( 109 ) to prevent the size of the iris opening ( 111 a ) from reducing further.
  11. 11 . The crimping device ( 100 ) as claimed in claim 10 , wherein the one or more stoppers ( 103 ) are removably coupled to a base plate ( 101 ).
  12. 12 . The crimping device ( 100 ) as claimed in any of the above claims , wherein the prosthetic device is one of a balloon-expandable prosthetic device or a self-expandable prosthetic device.
  13. 13 . The crimping device ( 100 ) as claimed in any of the above claims , wherein the prosthetic device is one of a vascular stent or a trans-catheter prosthetic heart valve.

Description

FIELD OF INVENTION The present invention relates to an apparatus and a method of radially collapsing a prosthetic device that has a support structure i.e. a frame which is radially collapsible and expandable such as a stent/scaffold. Specifically, the invention relates to reducing diameter of trans-catheter prosthetic heart valves (THV) including a support structure (stent/scaffold/frame) and leaflets made of biological tissue material or a synthetic material which are radially collapsible. BACKGROUND Generally, prosthetic devices that are targeted for implantation within a lumen of a body vessel include a support structure or a frame that is radially collapsible and expandable. The support structure/frame of the prosthetic device is cylindrical in shape and may include a uniform diameter or a tapered shape or may include varying diameter across its axial length. Such a prosthetic device is implanted by introducing it into a lumen of a body vessel by a known catheterization technique which includes radially collapsing (also referred to as ‘crimping’) the prosthetic device on the delivery catheter. It is known to a skilled person that crimping of a prosthetic device is necessary to make it possible to reduce the entry profile and thus introduce it into and advance it through a patient's vasculature to the implantation site where the prosthetic device is implanted by radially expanding the frame. The frames of these devices may be self-expanding or balloon expandable. Balloon-expandable prosthetic devices are generally crimped from an initial large diameter to a reduced diameter on the balloon of a balloon catheter. The prosthetic device is radially expanded at the implantation site by expanding the balloon by pressurizing it with a fluid, generally saline. A skilled person is familiar with structure and functioning of a balloon catheter. The prosthetic device, crimped on the balloon of a delivery balloon catheter, must be firmly secured onto the balloon. If the device is loose on the balloon, it may change its position on the balloon and even may get dislodged from the balloon during its introduction into and subsequent maneuvering through the patient's vasculature. Prosthetic devices that are not properly secured to the balloon may slip/dislodge and either be lost or potentially get embolized. In addition, crimping should be done in such a way as to minimize or prevent distortion of the prosthetic device and damage to the components of the prosthetic device. At the same time, the crimping process should not cause any damage to the balloon which may lead to leakage of blood into the balloon or leakage of inflation fluid out from the balloon. Such damage may weaken the balloon causing its bursting. The process of crimping includes positioning the prosthetic device (also referred to as ‘prosthesis’) with at least partially expanded diameter over the collapsed or partially expanded balloon of the balloon catheter and then crimping the prosthesis over the balloon using a crimping device, also referred to as a ‘crimper’. Classically, crimpers are provided with movable elements referred to as “jaws” which have inclined surfaces. The jaws when assembled, collectively form an aperture (also referred to as an opening) similar to an iris aperture of a camera. This opening has a depth enough to at least partially accommodate a prosthesis that is at least partially in a radially expanded form. The shape of the opening is a uniform polygon which may be described as nearly circular. These jaws move in a synchronous manner to reduce or increase the size/diameter of the aperture. The crimper includes a mechanism for such movement of the jaws. As mentioned above, the iris opening formed by the inclined surfaces of the jaws is a regular polygon with nearly circular shape. It is obvious to a skilled person that increasing the number of jaws will result in more number of sides of the polygon formed by them. The shape of the opening formed by more number of jaws will form a smoother circle than less number of jaws. This is because the length of sides of the polygon will be shorter as the number of jaws increases. The crimpers available in market generally incorporate twelve jaws which are found adequate and optimal. It is advisable that the minimum size of the iris opening may be controlled so as to avoid over-crimping which may cause possible damage to the frame structure and also to the soft elements within the device such as soft biological tissue, polymeric components etc. Traditionally, the replacement of a defective heart valve of a patient has been carried out by open heart surgery which has a higher risk as the patients requiring heart valve replacement are of old age, generally more than 70 years with concomitant comorbidities. Many patients are not clinically fit enough to undergo such surgery and hence cannot be treated. In recent years, trans-catheter prosthetic heart valves (THV) have become more popular as this tec