Basic Safety, Essential Performance, and EMC

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Basic Safety, Essential Performance, and EMC

• Frank OBrien
• www.obcompman.com

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Topics

• IEC 60601-1, 3rd edition, pre-FDIS
  text2004-04Medical electrical equipment Part
  1 General requirements for basic safety and
  essential performance
• Background
• Basic Safety, Essential Performance
• Risk Management Process
• New Requirements of Interest
• Electrical, Mechanical, Thermal

3
Topics

• IEC  60601122001 A12004-09Medical
  electrical equipment Part 1-2 General
  requirements for safety Collateral standard
  Electromagnetic compatibility Requirements and
  tests
• Overview of changes
• EMC essential performance

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Jurisdictional Authority

• 2nd edition in use
• IEC 60601-11988 A11991 A21995
• Forms the basis for national/regional consensus
  standard in all major medical device markets
• Including US, Europe, Japan, Canada,
  Australia/New Zealand, South Korea, China, Brazil

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SC62A Working Groups

• WG 5 Ergonomics and graphical symbols
• WG 11 Medical electrical systems
• WG 14 Testing to General Safety Standard
• WG 15 Risk management
• WG 16 Electrical hazards
• WG 17 Mechanical hazards
• WG 18 Overheating, fire protection and other
• WG 22 Programmable electrical medical systems
  (PEMS)

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Release Schedule
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IEC 60601-1, Collaterals, Particulars
Collateral Standards
Requirements for specific technologies and/or
hazards
General Standard 60601-1
60601-1-2 EMC
60601-1-3 Radiation Protection
60601-1-6 Usability
60601-1-8 Alarms
Particular Standards
Requirements for specific equipment types
60601-2-2 High Frequency Surgical Equipment
60601-2-1 Medical Electron Accelerators
60601-2-38 Electrically Operated Hospital Beds
60601-2-50 Infant Phototherapy Equipment
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Collaterals Inserted into General Standard
IEC 60601-1-4, PEMS (software)
Clause 14
IEC 60601-1, 3rd Edition
IEC 60601-1-1, Systems
Clause 16
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Scope, Clause 1.1

• Applies to the BASIC SAFETY and ESSENTIAL
  PERFORMANCE of MEDICAL ELECTRICAL EQUIPMENT and
  MEDICAL ELECTRICAL SYSTEMS

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Terminology, Clauses 3.63, 3.64

• ME Equipment
• Having an APPLIED PART or detecting/transmitting
  energy with PATIENT and intended to
  diagnose, treat or monitor or to compensate or
  alleviate disease, injury or disability
• Includes necessary ACCESSORIES
• ME System
• Combination of equipment at least one of which
  is ME EQUIPMENT

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Terminology, Clauses 3.10, 3.27

• Basic Safety
• Freedom from unacceptable RISK directly caused
  by HAZARDS when ME EQUIPMENT is used in NORMAL
  and SINGLE FAULT CONDITION
• Essential Performance
• Performance necessary to achieve freedom from
  unacceptable RISK
• Would absence or degradation of function result
  in unacceptable risk?

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Terminology, Clauses 3.39, 3.102, 3.38

• Hazard potential source of harm
• Risk Probability Severity
• Harm physical injury or damage to health or
  property

ISO 14971
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Risk Management Process, Clause 4.1, 4.2, 4.7

• requirements shall apply in NORMAL USE and
  reasonably foreseeable misuse
• A RISK MANAGEMENT PROCESS complying with ISO
  14971 shall be performed
• Residual RISK must be acceptable
• ME Equipment shall be SINGLE FAULT SAFE (free
  of unacceptable RISK under SINGLE FAULT CONDITION)

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Risk Management Process, 4.3

• Manufacturer identifies which functions are
  Essential Performance
• Determined by manufacturers policy for Risk
  acceptability
• Collateral and Particular Standards aligned
  with 3rd edition are expected to identify
  specific Essential Performance, Annex A, 3.27

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Risk Management Process

• When desired, in many cases, still a test
  standard with pass/fail criteria
• Can presume acceptable risk with compliance with
  Clauses containing verifiable requirements
• Annex A, Guidance and Rationale, Clause 4.2
• 2nd Edition was foremost a test standard with
  pass/fail criteria
• When desired, allowed risk analysis to evaluate
  alternative constructions offering equivalent
  degree of safety, Clause 3.4

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Risk Management Process

• A formal Quality System is NOT required
• A quality system facilitates dealing with risk
  management in a systematic way
• PEMS requires a Development Life Cycle
• An explanatory note to Clause 14.4 references IEC
  62304, (under development), which requires
  q-system
• FDA QSR requires a q-system w/design controls
• Where a documented design/development process
  exists, it shall incorporate the risk mgt process
• ISO 14971, Clause 3.2

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Risk Management Process

• Risk analysis
• Intended use/intended purpose identification
• Hazard identification
• Risk estimation

Risk assessment

• Risk evaluation
• Risk acceptability decisions

Risk management

• Risk control
• Option analysis
• Implementation
• Residual risk evaluation/Overall risk acceptance

• Post-production information
• Post-production experience
• Review of risk management experience

ISO 14971 Figure 1
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Risk Regions
Frequent
Intolerable
Probable
Probability
ALARP As Low As Reasonably Practicable
Occasional
Remote
Broadly Acceptable
Improbable
Incredible
Negligible
Marginal
Critical
Catastrophic
Example based onISO 14971, Fig E.1
Severity
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Development Life Cycle Process(facilitates risk
mgt, not required)
Verification of Risk Controls
1.Requirements, Analysis, Specifications
7. Systems Test
Validation
Ongoing Risk Analysis
Verification
6. Integration Test
2. Top-Level Design, Specification
5. Module Test
3. Detailed Design, Specification
Verification
4. Implementation
Example based on Fig H.2 (PEMS)
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New Requirements of Interest

• Use of ITE (computer) Power Supplies acceptable
  with
• ME Systems, Clause 16, Annex I
• If ITE in patient environment, separation
  transformer is possible solution
• ME Equipment, Clause 8.5, 4.6
• Accessible surfaces are unlikely to contact
  PATIENT
• 2 MEANS OF OPERATOR PROTECTION (MOOP)
• Compliance with Leakage Current limits, Clause
  8.7
• 5/10 mA Earth, 100/500 uA Touch, (NC/SFC)

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New Requirements of Interest

• New TRAPPING ZONE mitigation options
• Gaps, 9.2.2.2, Table 20
• Safety Distances, 9.2.2.3, ISO 13852
• Guards, and Protective Measures, 9.2.2.4
• Includes collision detection systems
• Continuous Activation, 9.2.2.5

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New Requirements of Interest

• Reduced TENSILE SAFETY FACTORS, Clause 9.8, Table
  21
• Material TENSILE STRENGTH and all external forces
  are quantifiable and accurate
• Safety Factors reduced by 37.5 (e.g. from 4 to
  2.5)

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New Requirements of Interest

• Maximum allowable surface temperatures are time
  dependent, and increased, Clause 11.1, Tables 23
  and 24
• Example from Table 24
• Applied Parts gt 41 C need to be disclosed in IFU

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EMC, IEC 60601-1-22001

• Became effective in Europe in Nov 2004 (DOW)
• Many changes

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Major Changes to IEC 60601122001

• Emissions exemption deleted
• New requirements for Harmonic emissions and
  Flicker for class B
• Allowance for ITE
• Extensive disclosure documentation requirements
• Labeling

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Major Changes to IEC 60601122001

• New Immunity requirements
• Conducted 150 kHz to 80 MHz
• Radiated extended to 2.5 GHz
• ESD 6 kV contact
• EFT Burst 2 kV power lines 1 kV signal
  lines
• Surge 2 kV line to gnd 1 kV line to line
• Voltage dips and interruptions
• Magnetic Fields 3A/m.
• ESD exemption

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Major Changes to IEC 60601122001

• Performance and safety based Passing at reduced
  levels is no longer allowed if function is
  associated with Essential Performance
• Extensive compliance criteria
• Compliance required during and after a test
• Essential Performance determination
• Applies to Systems and may require risk analysis
• Non-medical electrical equipment may be exempt.

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IEC 60601-1-2, Amendment12004-09

• Removes Definition and Capitalization from
  Essential Performance term
• Allows the developing interpretation in IEC
  60601-1 to drive the application in 60601-1-2
  rather than the other way around
• essential performance is identified and
  disclosed by manufacturer, Clause 3.201.2
• Annex GGG, Guidance for identification of
  essential performance, refers to draft 3rd
  edition

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EMC Essential Performance

• IMMUNITY TEST LEVELS represent normal use
  environment, Clause 36.202.1.a
• During Immunity testing, each function
  associated with essential performance is tested,
  Clause 36.202.1.c
• During Immunity testing, compliance criteria for
  essential performance is specified in Clause
  36.202.1.j
• Shall be able to provide identified essential
  performance and remain safe

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Summary

• IEC 60601-1, 3rd Ed. expected in Dec 2005(?)
• National/regional versions mid-late 2006(?)
• Older versions withdrawn, mid-late 2009-2011(?)
• Risk Management Process Required
• Can presume acceptable risk with verifiable
  requirements
• Essential Performance Required
• No unacceptable risk from loss of function
• EMC essential performance is disclosed