# US 10,307,274 B2 · Methods for uniform crimping and deployment of a polymer scaffold > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,307,274 B2 - Document ID: US10307274B2 - Status: Granted - Kind: B2 - Application number: 15/383,821 - Filed: 2016-12-19 - Published: 2017-04-06 - Granted: 2019-06-04 - Earliest claimed: 2011-07-29 - Assignees: Abbott Cardiovascular Systems Inc. - Applicants: Abbott Cardiovascular Systems Inc. - Inventors: John Stankus; Benjamyn Serna - Web page: https://patentgrep.com/patent/US10307274B2 ## CPC - A61F 2/915: with bands having a meander structure, adjacent bands being connected to each other - A61F 2/958: Inflatable balloons for placing stents or stent-grafts - A61F 2/9522: {Means for mounting a stent or stent-graft onto or into a placement instrument} - A61F 2002/91566: {connected trough to trough} - A61F 2240/001: Designing or manufacturing processes - Y10T 29/49908: Joining by deforming - Y10T 29/49925: Inward deformation of aperture or hollow body wall - Y10T 29/49936: Surface interlocking - A61F: FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS (dental prosthetics A61C) - Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION ## 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. ## Claims ### Claim 1 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. ### Claim 2 (depends on 1) The method of claim 1, wherein the scaffold has a temperature close to, but below a glass transition temperature (TG) of poly(L-lactide) during the plastically deforming the scaffold onto the balloon surface. ### Claim 3 (depends on 1) The method of claim 1, wherein the balloon has N pre-set folds, and when the scaffold has Dmin the N pre-set folds are at least partially retained. ### Claim 4 (depends on 3) The method of claim 3, wherein the crimping includes the step of pressurizing the balloon while the scaffold has an intermediate diameter between the pre-crimp diameter and Dmin. ### Claim 5 (depends on 3) The method of claim 3, wherein the N pre-set folds are fully retained when the scaffold has Dmin. ### Claim 6 (depends on 1) The method of claim 1, wherein the crimped diameter is less than a value derived from equation 1 or equation 2. ### Claim 7 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. ### Claim 8 (depends on 7) The method of claim 7, wherein the scaffold has a temperature close to, but below a glass transition temperature (TG) of poly(L-lactide) during the plastically deforming the scaffold onto the balloon surface. ### Claim 9 (depends on 7) The method of claim 7, wherein a first and second ring of the plurality of rings are adjacent each other and adjoined by no more than four links, and wherein one of the no more than four links is connected to the first ring at a Y-crown and the second ring at a W-crown. ### Claim 10 (depends on 7) The method of claim 7, wherein the scaffold is cut from a tube having a diameter larger than the nominal inflation diameter. ### Claim 11 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.