SBS - The best value in QMS software

SIP/SOP requirements for USB port used for charging

EMengineer

Involved In Discussions
#1
Hi everyone,

I have read many useful topics related to this question, but because of the large amount of information and opinions I got confused.
We have internally powered (3.7 VDC) body worn device with CF and BF applied parts and which is charged via USB. Data is send through BT thus the data pins are not used, thus when used on patient there is no connection to other devices.
The device is programmed that it could not be used while charging, thus the risk of mains on SIP/SOP is reduced. Is it possible to cover this with risk by not allowing charging while in use + warning + instructions (operator would be medical personel)?
Although there could be misuse - charging the device on the patient even if the device is not functioning. For example, the operator would charge the device enough to allow one measurement, thus it is not removed from the patient.
My question is about insulation between USB and applied part in such misuse case. Do I understood correctly that USB port shall galvanically be isolated from AP by 2 MOPP's for working voltage (5 VDC) and 1 MOPP for maximum mains voltage (according Fig J.4). In this case the largest a.c and c.d values 1 MOPP for 250 Vrms are - 4 mm c.d and 2,5 mm a.c (when 2 MOPP for 5 VDC are 3,4 mm c.d and 1,6mm a.c). Also dielectric strength test of 1500V should be applied. I hope I did get this part right.
But is it possible to use earlier mentioned risk mitigation measures reduce the potential for such misuse to an acceptable level? Or in any case the galvanic isolation should be used?

j4.png
 
Elsmar Forum Sponsor

Peter Selvey

Staff member
Moderator
#2
It's not required in the standard if the intended use, instructions and design are such that the device should be removed from the patient during charging. But it could be considered under general risk management.

It depends on the type of contact with the patient. Key point of concern would be electrodes or other low impedance patient contact, especially long duration, unconscious. In these cases, it can makes a lot of sense to have isolation between those parts and the USB supply as a risk control measure.

Since it is a risk control measure outside of the standard, it could be a little relaxed as well for the criteria (test voltage, creepage etc.). The 1 MOPP requirements in the standard are based on the insulation being continuously stressed with mains voltage for ~10 years, so 1.5kV/4mm is a huge overkill for this kind of situation. You might find an off the shelf USB isolator that has for example 1kV isolation, which is fine in my opinion.
 

EMengineer

Involved In Discussions
#3
Dear Peter, thank you for your answer ir really became clearer. There is one more question about separation of AP. Do I understood right that the only solid insulation is 1MOPP between patient circuit and Enclosure based on mains voltage and 2MOPP based on working voltage between internal circuit and enclosure. There are only the limiting resistors and buffers between AP and internal circuit. In this case the single fault condition during leakage current measurement would be short circuit of limiting resistor? Do you need additional ac/cd from battery operated internal circuit ant AP?
 

Peter Selvey

Staff member
Moderator
#4
That sounds like something we were discussing in another thread. The standard is written around insulation between circuits but does not fit for parts that are intended to limit currents arising from within a circuit.

In my opinion, it's OK to ignore the standard for ac/cd, dielectric strength within circuits as long as the voltages and currents are inherently low, which is usually the case for circuits that are used for monitoring and measurement such as ECG, EEG. The potential harm from these currents is is relatively low, compared to say contact with 230V mains.

However, if the circuit is high powered (higher voltage, higher currents) then use of properly approved safety components (capacitors, resistors) along with ac/cd is reasonable. Examples are high voltage simulators, electrosurgery. The limits in 601-1 might still be overkill, but some limits should still be applied, maybe based on IEC 60664-1 or some particulars which usually have more reasonable limits.
 
Thread starter Similar threads Forum Replies Date
B How to apply external voltage to SIP/SOP IEC 60601 - Medical Electrical Equipment Safety Standards Series 2
J Application of mains voltage on SIP/SOP connectors of medical device IEC 60601 - Medical Electrical Equipment Safety Standards Series 3
F SIP/SOP - Mains Power and Medical Device Ethernet Ports IEC 60601 - Medical Electrical Equipment Safety Standards Series 12
R Appearance of an External Voltage on SIP/SOP (Medical Devices) IEC 60601 - Medical Electrical Equipment Safety Standards Series 15
S High Voltage inside Ultrasonic Probes - Do SIP/SOP ports require isolation? IEC 60601 - Medical Electrical Equipment Safety Standards Series 2
A Unused SIP/SOPs - IEC 60601-1 and IEC 60601-1-2 IEC 60601 - Medical Electrical Equipment Safety Standards Series 1
O EMC - EFT (Electrical Fast Transients) on SIP couples erroneously with other cable CE Marking (Conformité Européene) / CB Scheme 1
G Metal Scale (SIP-Societe Genevoise) change in size over time? General Measurement Device and Calibration Topics 8
P How to add Voip features (ring group, virtual receptionist) into Cisco SIP PBX in C#? Medical Information Technology, Medical Software and Health Informatics 1
G SIP MU-214 Measuring Machine - Anyone modernize one? Capability, Accuracy and Stability - Processes, Machines, etc. 1
A IEC 60601-1 SIP/SIO Isolation and Touch current requirements IEC 60601 - Medical Electrical Equipment Safety Standards Series 1
E Procedure ( SOP) for Device Master Record ( DMR ) and for Device History Record (DHR)? 21 CFR Part 820 - US FDA Quality System Regulations (QSR) 1
M WI vs SOP - Shipping/Receiving Document Control Systems, Procedures, Forms and Templates 3
C Language of SOPs and SOP IDs Document Control Systems, Procedures, Forms and Templates 7
H SOP Template for seeking regulatory clearance - MDSAP Document Control Systems, Procedures, Forms and Templates 6
K Looking for guidance to write an SOP on Statistical Methodologies? Statistical Analysis Tools, Techniques and SPC 7
S Converting SOP MDD to MDR Noob ISO 13485:2016 - Medical Device Quality Management Systems 4
K What to include in SOP Definitions section Document Control Systems, Procedures, Forms and Templates 3
D ISO 13485 - 7.3.6 Design and development verification - Do most folks create a separate SOP? ISO 13485:2016 - Medical Device Quality Management Systems 4
D Naming of SOP doc's - Specific to Calibrations ISO 13485:2016 - Medical Device Quality Management Systems 2
Anonymous16-2 SOP (Standard Operating Procedure) Numbering Document Control Systems, Procedures, Forms and Templates 7
C SOP Template needed for ISO 13485 6.3 Infrastructure ISO 13485:2016 - Medical Device Quality Management Systems 9
C SOP unification. Revision No, Revision history Document Control Systems, Procedures, Forms and Templates 4
D Recent changes to ISO 14971 - SOP required for managing standard revisions ISO 13485:2016 - Medical Device Quality Management Systems 1
N Agile SOP for SaMD IEC 62304 - Medical Device Software Life Cycle Processes 3
S SOP for ISO 13485:2016 Quality related Software validation ISO 13485:2016 - Medical Device Quality Management Systems 9
R Is it required to have an SOP for external audits? Medical Device and FDA Regulations and Standards News 7
J Looking for a template SOP for UDI implementation for EU Medical Devices EU Medical Device Regulations 0
D Sample Calibration SOP for ISO 13485 General Measurement Device and Calibration Topics 4
Q Software SOP - Use and maintenance of an ERP system Software Quality Assurance 6
M What to do in SOP Phase of Head unit testing? IATF 16949 - Automotive Quality Systems Standard 0
H Should I mention machine/Equipment password In SOP? Qualification and Validation (including 21 CFR Part 11) 4
W SOP examples wanted - Soil, Concrete and Asphalt testing ISO 17025 related Discussions 3
F Linking an ISO 31000 Risk management SOP to ISO 17025 ISO 17025 related Discussions 2
pashah Looking for Clinical Evaluation SOP acc. MEDDEV and EU MDR Other Medical Device Related Standards 1
M SOP Sample for BC/ISO22301 (Business Continuity) wanted Business Continuity & Resiliency Planning (BCRP) 4
M Risk/Benefit vs. benefit-risk - Revising an SOP covering Risk Management with the MDR in mind EU Medical Device Regulations 10
A How to manage the QMS system and SOP during the transition from MDD to MDR EU Medical Device Regulations 4
V Protocol, report or SOP for threshold analysis? Human Factors and Ergonomics in Engineering 0
V Nature of references allowed to be cited in the SOP US Food and Drug Administration (FDA) 2
W SOP for Vigilance reporting covering multiple requirements Document Control Systems, Procedures, Forms and Templates 3
M Charging consulting fees for SOP development and guidance Document Control Systems, Procedures, Forms and Templates 14
J Just Venting - Do you refer directly to MDR or you just refer to SOP's? CE Marking (Conformité Européene) / CB Scheme 3
E CSR SHIPPING - Need suggestions for making SOP/WI for our shipping dept (automotive)... Customer and Company Specific Requirements 11
S Should there be a SOP on Cybersecurity? ISO 14971 - Medical Device Risk Management 1
T The difference between SOP and Kaizen Standardization Lean in Manufacturing and Service Industries 2
J Nonconforming product procedures SOP help :) Nonconformance and Corrective Action 2
G NIST SOP 29 - Assignment of Uncertainty - Question General Measurement Device and Calibration Topics 0
A SOP for software validation of software in medical device IEC 62304 IEC 62304 - Medical Device Software Life Cycle Processes 5
S SOP Training/Competence in 24/7 Operation contractor company ISO 9000, ISO 9001, and ISO 9004 Quality Management Systems Standards 7

Similar threads

Top Bottom