Evaluation of MOP (Means of Protection)

F

fish71

#1
Dear All,

I hope you can help me regarding the evaluation of MOOP and MOPP of a medical device. The medical device is a class 1 device with metal enclosure connected to earth. The device has 1 applied part. The applied part, has a metal enclosure, is powered with 12 V and is not connected to earth. Beyond that the device has an earthed metal touch panel with plastic front powered with 12 V. The touch panel is accessible both to user and to the patient. The internal power supply board meets 2 MOPP regarding i/p to o/p (4 kV high voltage test and 8 mm creepage and 5 mm clearance) and 1 MOPP regarding i/p to earth (1.5 kV high voltage test and 4 mm creepage and 2.5 mm clearance). My question is how shall the number of MOP be defined in the insulation diagram?

- for power supply board i/p to o/p must be 2 MOPP this is clear.
- what about the MOP between mains and the touch panel? The power board provides only 1 MOPP (between i/p to earth).
- and how shall the MOP of the applied part be defined.

Thank you for your help!
 
Elsmar Forum Sponsor

Peter Selvey

Staff member
Super Moderator
#3
Maybe one point to clear up is that earthing also counts as 1 MOP (provided it passes all the tests in 8.6).

So if the PSU has 1 MOP mains to earth, and earthing is 1MOP, you have 2 MOP.

In a typical simple but solid construction, there will be a clear 2 MOPP barrier between mains and secondary (4kV / 8mm) , 1 MOPP to earth (1.5kV / 4mm), and 1 MOP for the the earth (0.1ohm/25A). With this simple construction we can forget about mains voltages whether we are talking secondary, user controls, touch panels, earth, patient etc etc.

IEC 60601-1 starts to get confusing after this point in how it deals with secondary voltages and also F-type insulation, especially in the case where the patient may be also the operator (touch panels etc). But that is another story.
 

occounty

Involved In Discussions
#5
Hi Peter,

I have a query regarding your reply.

You are stating that 'the PSU has 1 MOP mains to earth, and earthing is 1MOP, you have 2 MOP'

What do you mean by 1 MOP mains to earth?

I would say that generally speaking, there is galvanic isolation offered in PSU so that is 1 MOP there and I agree that earthing is another 1 MOP.


That is how I would justify the 2 MOP barrier. Would like to know your thoughts on that.:)
 

phase90

Starting to get Involved
#7
Hi Peter,
Yes it does get confusing. So, if the system is a class I, meeting mains to secondary MOP and mains to earth MOP requirements, then any SIP/SOPs or any applied parts only have to be concerned with MOPs to secondary voltages or to earth (in BF/CF cases)? Or does an insulation diagram still need to list MOPs to mains for those?
 

Peter Selvey

Staff member
Super Moderator
#8
The common mistake in insulation diagrams is to look at it as a black box from the outside. So for example, the diagram will show mains to secondary, mains to enclosure, mains to signal IO, mains to patient as separate paths to analyse. There is a rough overview of the internal part but it is usually far from accurate.

The correct way is a white box approach which identifies where the physical isolation is. I even go so far as to list all components forming a particular barrier, such as transformers, optocouplers, capacitors, and PCB spacing.

If the same insulation serves all three paths (operator, secondary, signal IO, patient) and meets the highest needs (2MOPP) then it only needs to be shown once.

A white box approach also highlights some unexpected parts, for example, a mains switch often provides mains-operator 2MOP that is unrelated to much inspected mains-secondary isolation. Or single insulated mains wiring routed such that it could contact secondary parts that are not protectively earth, or non-approved secondary wiring near a mains heatsink.
 

Marcelo

Inactive Registered Visitor
#9
So, if the system is a class I, meeting mains to secondary MOP and mains to earth MOP requirements, then any SIP/SOPs or any applied parts only have to be concerned with MOPs to secondary voltages or to earth (in BF/CF cases)? Or does an insulation diagram still need to list MOPs to mains for those?
If main to secondary provides only 1 MOPP or MOOP, you still would need to show where the other MOPP or MOOP is (to fulfill the requirement of two means of protection).

In the case of SIP/SOPs and applied parts, you should take care there may be some additional MOP requirements, such as the separation of F-type applied parts or for non-earthed type B applied parts, or
 
Thread starter Similar threads Forum Replies Date
shimonv Clinical evaluation report for class I device EU Medical Device Regulations 1
A Applicability of Photobiological Safety Evaluation for LED used in medical devices Reliability Analysis - Predictions, Testing and Standards 1
P GSPRs / Clinical Evaluation EU Medical Device Regulations 3
silentmonkey Overall Benefit/Risk Analysis - Risk Management VS Clinical Evaluation ISO 14971 - Medical Device Risk Management 3
M NICE Medical Technology Evaluation Programme - Recommendations Service Industry Specific Topics 0
Q Summative Usability Evaluation Testing: prior or during Clinical Investigation? Human Factors and Ergonomics in Engineering 6
S Regular updates of clinical evaluation report EU Medical Device Regulations 6
K Surface finish (Evaluation Length) Inspection, Prints (Drawings), Testing, Sampling and Related Topics 3
M Clinical Evaluation Benchmark vs. Equivalent EU Medical Device Regulations 2
M IVDR and Performance Evaluation Plan CE Marking (Conformité Européene) / CB Scheme 2
S User evaluation for self monitoring blood glucose test systems US Food and Drug Administration (FDA) 4
S Australia TGA Clinical Evaluation Report (CER) Other Medical Device Regulations World-Wide 0
S API Spec. Q1 clause 5.6.1.2 On site evaluation Oil and Gas Industry Standards and Regulations 10
B Biological evaluation plan and report Other Medical Device Related Standards 5
F Biocompatibility evaluation for Hardware/Interface Components? Other Medical Device Related Standards 12
B Clinical Evaluation Expert Panels - MDR EU Medical Device Regulations 1
T Clinical evaluation of a new medical device EU Medical Device Regulations 0
dgrainger Informational MDCG 2020:13 - Clinical evaluation assessment report template EU Medical Device Regulations 0
S A clinical performance evaluation study with an IVD product as Investagional Use product - Clinical Monitor requirements 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 4
B AS9100 8.4.1 Supplier Selection/Evaluation criteria and reevaluations AS9100, IAQG, NADCAP and Aerospace related Standards and Requirements 13
R Clinical evaluation without clinical data - MDR Article 61(10) EU Medical Device Regulations 8
M Clinical Evaluation Plan vs. PMCF Plan EU Medical Device Regulations 24
K Biocompatibility evaluation of gas pathways Medical Device and FDA Regulations and Standards News 5
T HF testing / Summative evaluation for MDDS class I necessary? Human Factors and Ergonomics in Engineering 2
N Evaluation of service providers Supplier Quality Assurance and other Supplier Issues 2
M Can someone share a scrubbed version of Clinical Evaluation Plan (CEP) EU Medical Device Regulations 8
S EU MDR Annex XIV - Clinical Evaluation Plan - What do these methods mean? EU Medical Device Regulations 16
C Material from outside CER evaluation period CE Marking (Conformité Européene) / CB Scheme 8
DitchDigger IEC 60601-1 subclause 5.1 - Adequate evaluation in lieu of testing IEC 60601 - Medical Electrical Equipment Safety Standards Series 2
S Clinical Evaluation - Is this an ISO 13485:2016 requirement? ISO 13485:2016 - Medical Device Quality Management Systems 4
P SOUP anomaly evaluation for MMA (Mobile Medical Application) IEC 62304 clause 7.1.3 IEC 62304 - Medical Device Software Life Cycle Processes 6
M Informational How to perform a clinical evaluation of medical devices – Part 2 – Level of clinical evidence and what sufficient clinical evidence means Medical Device and FDA Regulations and Standards News 9
P IEC 62304 - evaluation of integration and system testing IEC 62304 - Medical Device Software Life Cycle Processes 4
R Supplier evaluation and business needs in the context of ISO 13485 ISO 13485:2016 - Medical Device Quality Management Systems 2
U Changes to Internal Processes and Risk Evaluation - Mitigations Risk Management Principles and Generic Guidelines 10
M Informational Work in progress at the FDA for biological evaluation – Color Hazard and RISk calculator (CHRIS) Medical Device and FDA Regulations and Standards News 0
M Informational How to perform a clinical evaluation of medical devices – Part 1 – Overview and sample of activities Medical Device and FDA Regulations and Standards News 0
T EU MDR Article 61- Clinical Evaluation EU Medical Device Regulations 2
pashah Looking for Clinical Evaluation SOP acc. MEDDEV and EU MDR Other Medical Device Related Standards 1
K Supplier re-evaluation (API Q1) Manufacturing and Related Processes 8
B Evaluation of Basic Safety during EMC Immunity or Climate Testing IEC 60601 - Medical Electrical Equipment Safety Standards Series 0
S ISO 10993 Biocompatibility Evaluation - Electronic thermometer Other Medical Device Related Standards 3
D Clinical Evaluation Report - Consultant Recommendations Consultants and Consulting 9
qualprod ISO 9001 Clause 9.1 - Monitoring measurement analysis and evaluation ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 6
M CER (Clinical Evaluation Reports) updates - Product Codes EU Medical Device Regulations 2
A Medical device CER (clinical evaluation report) training/seminar services EU Medical Device Regulations 2
M Informational US – National Evaluation System for Health Technology Coordinating Center (NESTcc) Solicits Public Comments for Data Quality and Methods Frameworks Medical Device and FDA Regulations and Standards News 0
M Informational IMDRF – Proposed update to Clinical Evaluation documents Medical Device and FDA Regulations and Standards News 0
M Informational MDCG 2019-3 Interpretation of Article 54(2)b – Pre- market clinical evaluation consultation procedure with the involvement of expert panels Medical Device and FDA Regulations and Standards News 0
TheMightyWife Clinical Evaluation MEDDEV 2.7.1 Rev 4 demonstration of equivalence EU Medical Device Regulations 6

Similar threads

Top Bottom