Radiation sterilization of implantable medical devices

摘要

A system and method for sterilization of medical devices includes methods for reducing the variance in dose levels over the medical device by either varying the dose levels for each pass before a radiation source, such as an electron beam, or by increasing the number of passes before a radiation source.

主权项

1. A method for sterilizing medical devices by irradiation, comprising:
determining radiation dose levels to apply to each of the medical devices, including
providing at least a first dose map and a second dose map for one of the medical devices, the first and second dose maps representing a distribution of received radiation over the medical device when the medical device is orientated in at least a first direction and a second direction, respectively, relative to a radiation source, wherein the first and second directions are determined from a density profile of the medical device, andcomputing a first dose level and a second dose level from the first and second dose maps and satisfying (a), (b) and (c):(a) the sum total of the computed first and second dose levels achieves a sterility assurance level (SAL) for the medical device,(b) the sum total of the computed first and second dose levels is less than a dose level causing damage to the medical device, and(c) when the medical device is irradiated using the first and second dose levels, the difference in the sum total of radiation received at a first location and a second location on the medical device is a minimum for the medical device orientated in the respective first direction and second direction relative to the radiation source; and exposing each of the medical devices to the first dose level when oriented in the first direction and the second dose level when oriented in the second direction; wherein the first dose level is different from the second dose level.