IEC TS 60601-4-6:2024

IEC TS 60601-4-6 ®
Edition 1.0 2024-04
TECHNICAL
SPECIFICATION
Medical electrical equipment –
Part 4-6: Guidance and interpretation – Voluntary guidance to help achieve basic
safety and essential performance with regard to the possible effects of
electromagnetic disturbances
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IEC TS 60601-4-6 ®
Edition 1.0 2024-04
TECHNICAL
SPECIFICATION
Medical electrical equipment –

Part 4-6: Guidance and interpretation – Voluntary guidance to help achieve

basic safety and essential performance with regard to the possible effects of

electromagnetic disturbances
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
ICS 11.040.01; 33.100.20 ISBN 978-2-8322-8809-2

– 2 – IEC TS 60601-4-6:2024 © IEC 2024
CONTENTS
FOREWORD . 5
INTRODUCTION . 7
1 Scope . 8
2 Normative references . 8
3 Terms, definitions and abbreviated terms . 8
3.1 Terms and definitions. 8
3.2 Abbreviated terms . 9
4 How to use this document . 9
5 General . 10
5.1 Mitigation of effects caused by EM DISTURBANCES . 10
5.2 Implementing well-proven techniques and measures for mitigating the
effects that can be caused by EM DISTURBANCES . 10
5.2.1 General principles . 10
5.2.2 Choosing design techniques and measures from Annex A . 10
5.3 Documenting the well-proven techniques and measures used for mitigating
the effects that can be caused by EM DISTURBANCES . 13
5.3.1 ME EQUIPMENT or ME SYSTEM . 13
5.3.2 Non-ME EQUIPMENT . 14
Annex A (informative) Detailed guidance on the techniques and measures for
mitigating the effects that can be caused by EM DISTURBANCES . 15
A.1 Techniques and measures that might be helpful in project management,
planning and specification . 15
A.1.1 Techniques and measures for project management and planning . 15
A.1.2 Techniques and measures for use when creating a design specification . 15
A.1.3 Specifying EMC test standards to help ensure availability . 16
A.1.4 Protecting against high impact, unusual and malicious EM DISTURBANCES . 19
A.2 Techniques and measures that might be helpful in system design . 20
A.2.1 General . 20
A.2.2 Separating system parts necessary for achieving BASIC SAFETY or
ESSENTIAL PERFORMANCE from system parts that are not important for
BASIC SAFETY or ESSENTIAL PERFORMANCE . 20
A.2.3 Recording how the design specifications are achieved through design
choices . 21
A.2.4 Co-design electromagnetically diverse hardware/software in redundant
channels . 21
A.2.5 System integration, installation, and commissioning . 24
A.2.6 Fault detection and event data recording for later diagnosis . 25
A.2.7 Improving mitigation of the effects that can be caused by EM
DISTURBANCES in communication links . 26
A.2.8 Synchronization and resynchronization techniques . 28
A.2.9 Protection from persistent interference by monitoring retry counts . 28
A.2.10 Independent detection of EM DISTURBANCES and/or EMI . 29
A.2.11 Protection of systems from tampering via communication links to
external systems . 30
A.2.12 Robust, high-specification electromagnetic mitigation . 31
A.2.13 Techniques and measures to prevent RISKS being increased by
virtualization of memory and PROCESS resources (e.g. a "digital twin") . 31
A.2.14 Usability Engineering (Human Factors) . 32
A.3 Techniques and measures that might be helpful in operational design . 32

A.3.1 General . 32
A.3.2 Developing appropriate operation and maintenance instructions . 33
A.3.3 Designing appropriate maintenance techniques . 33
A.3.4 Limiting the possibilities for operation and hence mis-operation . 34
A.3.5 Protecting against operation errors . 34
A.3.6 Protecting against hardware or software modifications or manipulations . 35
A.3.7 Defensive programming techniques . 35
A.3.8 Limited use of interrupts . 38
A.3.9 Limited use of memory address pointer variables . 39
A.3.10 Avoiding recursion . 39
A.3.11 Error detection and correction for invariable memory . 40
A.3.12 Error detection and correction techniques in redundant designs . 41
A.3.13 Time-based error detection/correction in buses and interfaces . 42
A.3.14 Error detection and correction for variable memory . 43
A.3.15 Error detecting/correcting coding for ROM, RAM, buses, and interfaces . 45
A.3.16 Error detection and correction for logic and data processing . 45
A.3.17 Error detection and correction for electrical and electromechanical

components . 47
A.3.18 Caution when using hardware or software libraries . 48
A.3.19 Error detection and correction for electronic components . 48
A.3.20 Error detection/correction by monitoring program sequence (i.e.
watchdogs) . 51
A.3.21 Error detection and correction using multi-channel input/output

interfaces . 53
A.3.22 Using test patterns: static and dynamic. 53
A.3.23 Using fiber-optic cables for signals and data communications . 54
A.3.24 Techniques and measures for AC and DC power supplies/power
converters . 54
A.3.25 Monitoring of ventilation, cooling, and heating . 56
A.3.26 Careful use of wireless (radio) data communications . 57
A.3.27 Good electromagnetic engineering at every level of design . 58
A.3.28 Design to comply with EMC test specifications as set out in A.1.3 and
A.1.4 . 58
A.3.29 De-rating of hardware components, where appropriate . 59
A.3.30 Improve robustness of interrupts. 59
A.4 Techniques and measures that might be helpful in implementation,
integration, installation, and commissioning . 60
A.4.1 Providing information on constraints and additional measures . 60
A.4.2 Procuring materials, components, and products . 61
A.4.3 Assemble/integrate according to the design for adequate mitigation of
the effects that can be caused by EM DISTURBANCES . 62
A.4.4 Install/commission according to the design for achieving adequate
mitigation of the effects that can be caused by EM DISTURBANCES . 62
A.5 Techniques and measures that might be helpful in VERIFICATION and
validation (including testing) . 62
A.5.1 Applying VERIFICATION and/or validation techniques and measures . 62
A.5.2 VERIFICATION testing to the EMC test plan from A.1.3 and A.1.4 . 64
A.5.3 Using non-standardized ad hoc checks or tests . 65
A.5.4 Verifying correct installation and commissioning . 66
A.5.5 EMC tests before and after accelerated life tests . 67

– 4 – IEC TS 60601-4-6:2024 © IEC 2024
A.6 Techniques and measures that might be helpful in operation, maintenance,
repair, overhaul, refurbishment, and upgrade . 67
A.6.1 Assessment of changes in the ELECTROMAGNETIC ENVIRONMENT . 67
A.6.2 Assessment of continuing correct installation . 68
A.6.3 Maintaining adequate mitigation of the effects that can be caused by EM
, despite modifications or changes . 69
DISTURBANCES
A.6.4 Batch (lot) traceability . 70
A.6.5 Component changes, new supplier, dual / alternate source . 70
A.7 Techniques and measures that might be helpful in decommissioning . 71
A.8 Integrating third-party items into ME EQUIPMENT or ME SYSTEMS . 71
A.8.1 The general iterative approach . 71
A.8.2 Suppliers' certifications and electromagnetic assessments . 73
A.8.3 Custom-manufactured component parts . 73
...