Essential Performance of Mechanical Device?

[reyemka]

Looking for opinions on this question:

I have a prototype where all the intended use is provided via an approved mechanical device (no electronics). We've added electronics to the device to capture usage data for a clinical study. The electronics do not contribute to the intended use, and do not affect the clinical performance of the device.

We are reviewing 60601-1 to ensure the device is safe to use, and I'm wondering if, according to the standard, it would be considered to have essential performance?

I'm inclined to say no, but looking for your thoughts.

Thanks!

 

[Thukira]

Extract from IEC 60601-1, 3.1 edition (EP, cl. 3.27*) definition
* ESSENTIAL PERFORMANCE
performance of a clinical function, other than that related to BASIC SAFETY, where loss or degradation beyond the limits specified by the MANUFACTURER results in an unacceptable RISK .
NOTE ESSENTIAL PERFORMANCE is most easily understood by considering whether its absence or degradation would result in an unacceptable RISK.

EP process (Cl. 4.3*)
· During RISK ANALYSIS, the MANUFACTURER shall identify the EP of the MEE&S (1st para of 4.3)
· The MANUFACTURER shall specify performance limits between fully functional & total loss of the identified performance in both the NORMAL CONDITION & SINGLE FAULT CONDITION
· Follow full process of Cl. 4.3

And also;
· EP will impact test plan (Safety, EMC/I test etc)
· Changes in intended use͟ can change EP of device
· Particular Standards (60601-2-XX & 80601-2-XX) tend to have EP

RISK MANAGEMENT PROCESS (RMP) (4.2.2)
· RMP complying with ISO 14971 shall be performed & required
· Ubiquitous in standard.
· Therefore you can’t comply with IEC 60601-1 ed. 3.0 or 3.1 without complying with ISO 14971

 

[VinceTech]

can device lead to any harm and if any protection be implemented for it?

 

[Thukira]

can device lead to any harm and if any protection be implemented for it?

Can you elaborate your question ?

 

[Peter Selvey]

Based on the original description there is no essential performance. Someone could try to argue that the feedback data could lead to improvements in future device design hence they could be essential, but that's clearly a step too far with the interpretation. Essential performance should be limited to the actual device on the market (in use), not possible future devices.

The catch is design creep. I have seen cases where monitoring functions are deemed not essential, just diagnostic feedback for designers. Later someone says hey how about we do this, and it eventually evolves into a important clinical function. But, the designers continue to deem it non-essential based on the original decision.

Keep that in mind and you should be OK.

 

[VinceTech]

Based on the original description there is no essential performance. Someone could try to argue that the feedback data could lead to improvements in future device design hence they could be essential, but that's clearly a step too far with the interpretation. Essential performance should be limited to the actual device on the market (in use), not possible future devices.

The catch is design creep. I have seen cases where monitoring functions are deemed not essential, just diagnostic feedback for designers. Later someone says hey how about we do this, and it eventually evolves into a important clinical function. But, the designers continue to deem it non-essential based on the original decision.

Keep that in mind and you should be OK.

Further discussion. Assuming the electronics failure can lead to the mechanical device connects to supply mains, the protection for this failure mode is earthing the mechanical device. In this case, is the proper earthing of device is an essential performance? Thanks

Best regards,

 

[3dBUnderThe Limit]

No, protective earth should be considered as basic safety. Essential performance is related to a clinical function.