Tonia,
Assuming you are talking about F-Type applied parts, the relevant clause would be 8.5.2.1. The first paragraph sets the requirement which is seemingly contradicted by the third and fourth paragraphs but the subclause sheds more light on this. Basically, it is up to the manufacturer to determine, using their risk assessment, if multiple functions can be considered as multiple applied parts (thus requiring separation from one another in the case of an F-Type) or if multiple functions are to be treated as one applied part.
The need for separation between applied parts is driven by the single fault condition of applying mains voltage on the F-Type applied part while another patient connection is intentionally earthed. If leakage current limits would be exceeded, then you need separation. In the case of an SpO2 sensor, you may have enough solid insulation and creepage/clearance distances to prevent it from becoming electrically connected to earth (or supply mains), thus the circuit would not be completed (no current flow) and you would not need separation between the two parts.
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Wade Munsch
Regulatory Affairs Manager
Biotex, Inc.
Houston TX
United States
Website:
www.biotexmedical.com------------------------------
Original Message:
Sent: 19-Sep-2022 08:27
From: Tonia E. Bryant
Subject: Isolation Requirements
Greetings,
I have a question pertaining to isolation requirements for electronic medical devices.
We have a device that has optional temperature probe and SpO2 sensor that can be attached to a BP monitor. The temperature probe and SpO2 sensor electronics are electronically isolated from the rest of the electronics, but they are not electronically isolated from each other. IEC 60601-1 sheds some light on the subject, but I'm unsure of how to interpret.
My understanding is that any applied part has to be isolated from any other applied part (as well as being isolated from the rest of the instrumentation and the mains supply). Is this correct? Am I missing something?
Best, Tonia
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Tonia E. Bryant
Manager, Regulatory Affairs
Morrisville NC
United States
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