The impact of laser power on biocompatibility of the products

[Judy Abbott]

Good day,

To improve the bond strength of a welded joint between a Pt (90%)/Ir (10%) coil with 304 SS wire, the manufacturer increased the laser power. Now they are seeing discoloration and rust at the joint. What is this discoloration? How can it impact the biocompatibility of the guidewire? How can I mitigate the risk associated with this change? Thanks for sharing your ideas in advance!

 

[indubioush]

How could this be rust?
Is this device commercially distributed? If so, your change control process needs improvement.
Have you done testing to confirm that the bond strength in fact increases with this change?
What does your risk management documentation say about this risks associated with laser energy being to high?

 

[Judy Abbott]

Thanks! This change is not part of the manufacturing line yet. The impact of all the proposed changes has to be assessed before applying the change.R&D is testing the increase of the laser energy at this stage and they just wanted to know what is a good explanation of this discoloration and how it impacts the biocompatibility.

 

[indubioush]

Well that is a relief. This could be soot or discoloration due to heat. As for biocomp, I can't really answer that because I don't know much about those materials. Sorry.

 

[Judy Abbott]

Thank you!!

 

[planB]

Judy,

the discoloriosation could be attributed to physical and/or chemical modifications at the laser joint. EDX and SEM could provide you with a first clue what is happening at the welded joint. In case this is a pure surface phenomenon, an additional grinding/polishing step might address this issue.

In term of biocompatibility, you may want to re-investigate your inorganic leachables and extractables profile (e.g. via ICP) commensurate to nature of body contact of the affected component, and confirm that you do not introduce any new biological hazards. In case you introduce new manufacturing steps (grinding/polishing), you may want to consider the impact of these (new/changed) processes experimentally as well according to ISO 10993-18.

Hope this helps,

 

[Judy Abbott]

Judy,

the discoloriosation could be attributed to physical and/or chemical modifications at the laser joint. EDX and SEM could provide you with a first clue what is happening at the welded joint. In case this is a pure surface phenomenon, an additional grinding/polishing step might address this issue.

In term of biocompatibility, you may want to re-investigate your inorganic leachables and extractables profile (e.g. via ICP) commensurate to nature of body contact of the affected component, and confirm that you do not introduce any new biological hazards. In case you introduce new manufacturing steps (grinding/polishing), you may want to consider the impact of these (new/changed) processes experimentally as well according to ISO 10993-18.

Hope this helps,

Thanks a lot for your advice! That would be my starting point.