Uniform crimping and deployment methods for polymer scaffold

摘要

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 and maintain a relatively uniform arrangement of balloon folds about the inner surface of the crimped scaffold so that the scaffold expands in a uniform manner when the balloon is inflated.

主权项

1. A method for securing a scaffold to a balloon using a crimping device, the scaffold comprising a polymer and the balloon having pre-arranged folds, comprising the steps of:
crimping the scaffold to the balloon while the scaffold has a temperature of between a glass transition temperature (TG) of the polymer and 15 Deg. Celsius below the TG of the polymer, including the steps of
(a) disposing the scaffold on the balloon,(b) reducing the scaffold diameter from a starting size to a first size,(c) maintaining the first size for a first dwell period to allow for stress relaxation,(d) reducing the scaffold diameter from the first size to a second size,(e) maintaining the second size for a second dwell period, and(f) reducing the scaffold diameter from the second size to a third size;wherein the balloon has an inflated state for steps (a), (b), (c), (d) and (e), andwherein after step (f) substantially none of the pre-arranged folds are present in the balloon.