[gumby]

In the USA FDA would need to approve such a change for a device that could possibly kill the patient. And would be unlikely to say yes.

I once designed a hardware state machine out of TTL (no CPU, except a network interface that could only passively read and transmit the state) to ensure that a pressure vessel was safe (and this was ahead of the mechanical safety devices). Regularly someone would ask why we had this large device and didn't just replace it with a tiny MPU.

[SentinelLdnma]

This occurred before the device was submitted for its first 510(k) approval.

Also, companies have some discretion in what changes they re-submit to the FDA and what the decide to just document internally. There are guidelines, like if you change the OS you better resubmit, but there is a wide swath of gray area. The FDA is not looking at every code/hardware change request. They audit your process.

Edit: typos

[gumby]

Yeah, I'm on the small molecule side but did a combo device years ago and was shocked at how slack the device rules were compared to the drug side.

[SentinelLdnma]

Agreed. Class III hardware is well controlled (i.e., implants), but software (any class) and lower-class hardware is loco. My device was Class II.

[seehafer]

This change would have certainly increased overall risk so a new 510(k) would have been required if this device was already commercialized.

And had your management not backed down, and tried to push this through as a Letter to File, you'd have been well-within your rights to blow the whistle to FDA. There's not a FDA employee alive that wouldn't go "hold on there chief" to a device change of this magnitude.