Module 14: Design Development and Certification of Medical Devices
17/11/2023
GAMMA RAYS [ISO 11137: 1, 2, 3 ]
– Does not involve high temperatures / high humidity / high pressure
– Reasonably rapid
– Typically uses 60 Cobalt source to provide a specific “dose” – Placement near to the source
Masterclass: Lecture 11
The Organisation for Professionals in Regulatory Affairs
33
GAMMA STERILISATION
Ionizing radiation causes excitations, ionisations and, where water is present, free radical formation. Free radicals are powerful oxidising (OH, HO2) and reducing (H) agents, capable of damaging essential molecules in living cells. All three processes cause disintegration of essential cell constituents such as enzymes and the DNA. This results in cell death. The most biologically damaging forms of gamma radiation occur in the gamma ray window, between 3MeV and 10MeV. Cobalt-60 emits gamma radiation at the 1.17MeV and 1.33MeV level, - below the most effective range.
Masterclass: Lecture 11
The Organisation for Professionals in Regulatory Affairs
34
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