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US 10,307,274 B2Granted
Methods for uniform crimping and deployment of a polymer scaffold
AssigneeAbbott Cardiovascular Systems Inc.
InventorsJohn Stankus, Benjamyn Serna
Life of this patent
Estimating the term…
Abstract
A medical device-includes a scaffold crimped to a catheter having an expansion balloon. The scaffold is crimped to the balloon by a process that includes one or more balloon pressurization steps. The balloon pressurization steps are selected to enhance scaffold retention to the balloon while retaining, at least partially, the original balloon folds as the balloon is pressurized and de-pressurized within a crimper head. By at least partially retaining the original balloon folds, a uniformity of scaffold expansion by the balloon is improved.
Claims11
A method of crimping, comprising:
- using a balloon having a nominal balloon diameter;
- using a scaffold having a pre-crimp diameter and a network of rings having struts and crowns, and the rings are connected by links, wherein
- the rings and links are made from a polymeric material, and
- the pre-crimp diameter is larger than the nominal balloon diameter;
- and
- crimping the scaffold to the balloon to produce a crimped scaffold having a minimum crimped diameter (Dmin), wherein
- the scaffold is plastically deformed onto a surface of the balloon to form a fit that resists dislodgment of the scaffold from the balloon surface, and
- Dmin is equal to or less than a value derived from equation 1 for struts having an essentially square cross-section or from equation 2 for struts having a trapezoidal cross-section:
- (ØSwi+ØCrj+ØLwk)*(1/π)+2*WT (equation 1)
- (ØSwi+ØCrj+ØLwk)*(1/π) (equation 2)
- wherein
- ØSwi (i=1 . . . n) is the sum of n ring struts having width Swi;
- ØCrj (j=1 . . . m) is the sum of m crown inner radii having radii Crj (times 2);
- ØLwk (k=1 . . . p) is the sum of p links having width Lwk;
- and
- WT is a ring wall thickness.
13 more elements
A method of crimping, comprising:
- using a balloon having N pre-set folds and a nominal balloon diameter;
- using a scaffold having a pre-crimp diameter and a plurality of rings, wherein adjacent ring pairs are connected by links, wherein
- the rings and links are made from a polymeric material, and
- each ring comprises a pair of struts connected at a crown
- using a crimping mechanism, plastically deforming the scaffold onto the balloon surface to form a fit that resists dislodgment of the scaffold from the balloon, the crimping including the steps of:
- reducing the scaffold diameter from the pre-crimp diameter to an intermediate diameter, wherein the intermediate diameter is less than or equal to 33% of the pre-crimp diameter,
- pressurizing the balloon while the scaffold diameter is equal to, or less than the intermediate diameter,
- reducing the scaffold diameter from the intermediate diameter to a final diameter, and
- after the scaffold has attained the final diameter, placing the scaffold and balloon within a restraining sheath,
- wherein the balloon's N pre-set folds are retained when the scaffold and balloon are within the restraining sheath.
7 more elements
A method of crimping, comprising:
- using a balloon having N pre-set folds and a nominal balloon diameter;
- using a scaffold having a pre-crimp diameter and a plurality of rings, wherein adjacent ring pairs are connected by links, wherein
- the rings and links are made from a polymeric material,
- each ring comprises a pair of struts connected at a crown, and
- the pre-crimp diameter is larger than the nominal balloon diameter;
- and
- using a crimping mechanism, plastically deforming the scaffold onto the balloon surface to from a fit that resists dislodgment of the scaffold from the balloon, the crimping including the steps of:
- reducing the scaffold diameter from the pre-crimp diameter to an intermediate diameter, wherein the intermediate diameter is less than or equal to 33% of the pre-crimp diameter,
- pressurizing the balloon while the scaffold diameter is equal to, or less than the intermediate diameter,
- reducing the scaffold diameter from the intermediate diameter to a final diameter, and
- after the scaffold has attained the final diameter, placing the scaffold and balloon within a restraining sheath,
- wherein the balloon's N pre-set folds are retained when the scaffold and balloon are within the restraining sheath.
9 more elements
Dependencies are inferred from the claim text.