IEC 60601-2-33:2010/AMD2:2015

Amendment 2 - Medical electrical equipment - Part 2-33: Particular requirements for the basic safety and essential performance of magnetic resonance equipment for medical diagnosis

Amendement 2 - Appareils électromédicaux - Partie 2-33: Exigences particulières pour la sécurité de base et les performances essentielles des appareils à résonance magnétique utilisés pour le diagnostic médical

General Information

• Status: Published
• Publication Date: 17-Jun-2015
• ICS: 01 - GENERALITIES. TERMINOLOGY. STANDARDIZATION. DOCUMENTATION
• ICS: 11.040.55 - Diagnostic equipment
• Technical Committee: SC 62B - Diagnostic imaging equipment
• Current Stage: PPUB - Publication issued
• Start Date: 18-Jun-2015
• Completion Date: 18-Jun-2015

Standards Content (sample)

IEC 60601-2-33
Edition 3.0 2015-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
AM ENDMENT 2
AM ENDEMENT 2
Medical electrical equipment –

Part 2-33: Particular requirements for the basic safety and essential performance

of magnetic resonance equipment for medical diagnosis
Appareils électromédicaux –

Partie 2-33: Exigences particulières pour la sécurité de base et les performances

essentielles des appareils à résonance magnétique utilisés pour le diagnostic
médical
IEC 60601-2-33:2010-03/AMD2:2015-06(en-fr)
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 60601-2-33
Edition 3.0 2015-06
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
AM ENDMENT 2
AM ENDEMENT 2
Medical electrical equipment –

Part 2-33: Particular requirements for the basic safety and essential performance

of magnetic resonance equipment for medical diagnosis
Appareils électromédicaux –

Partie 2-33: Exigences particulières pour la sécurité de base et les performances

essentielles des appareils à résonance magnétique utilisés pour le diagnostic
médical
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
INTERNATIONALE
ICS 11.040.55 ISBN 978-2-8322-2700-8

Warning! Make sure that you obtained this publication from an authorized distributor.

Attention! Veuillez vous assurer que vous avez obtenu cette publication via un distributeur agréé.

® Registered trademark of the International Electrotechnical Commission
Marque déposée de la Commission Electrotechnique Internationale
---------------------- Page: 3 ----------------------
– 2 – IEC 60601-2-33:2010/AMD2:2015
© IEC 2015
FOREWORD

This amendment has been prepared by subcommittee 62B: Diagnostic imaging equipment, of

IEC technical committee 62: Electrical equipment in medical practice.
The text of this amendment is based on the following documents:
FDIS Report on voting
62B/977/FDIS 62B/987/RVD

Full information on the voting for the approval of this amendment can be found in the report

on voting indicated in the above table.

The committee has decided that the contents of this amendment and the base publication will

remain unchanged until the stability date indicated on the IEC web site under

"http://webstore.iec.ch" in the data related to the specific publication. At this date, the

publication will be
• reconfirmed,
• withdrawn,
• replaced by a revised edition, or
• amended.

IMPORTANT – The 'colour inside' logo on the cover page of this publication indicates

that it contains colours which are considered to be useful for the correct

understanding of its contents. Users should therefore print this document using a

colour printer.
_____________
INTRODUCTION TO AMENDMENT 2

This Amendment 2 has been developed to increase the FIRST LEVEL CONTROLLED OPERATING

MODE limit for the static field from 4 T to 8 T taking into account FDA, ICNIRP and other peer

reviewed scientific literature. In addition, a non-compulsory option, FIXED PARAMETER

OPTION:BASIC (FPO:B), is introduced to limit RF and gradient field outputs (peak and RMS) for

scanning PATIENTS with MR conditional implants. Consequently, text is proposed for the

Instructions for use to guide users in scanning PATIENTS with MR conditional implants.

Furthermore, references to newly published collateral standards have been updated.

201.1.3 Collateral standards

Replace, in the first sentence of the second paragraph, the reference to "IEC 60601-1-2:2007"

with "IEC 60601-1-2:2014”.
201.2 Normative references

Replace, under “Replacement”, the reference to "IEC 60601-1-2:2007" with the following:

---------------------- Page: 4 ----------------------
IEC 60601-2-33:2010/AMD2:2015 – 3 –
© IEC 2015

IEC 60601-1-2:2014, Medical electrical equipment – Part 1-2: General requirements for basic

safety and essential performance – Collateral standard: Electromagnetic disturbances –

Requirements and tests
Add, under “Replacement”, the following new references:

IEC 60601-1-6:2010, Medical electrical equipment – Part 1-6: General requirements for basic

safety and essential performance – Collateral standard: Usability
IEC 60601-1-6:2010/AMD1:2013

IEC 60601-1-8:2006, Medical electrical equipment – Part 1-8: General requirements for basic

safety and essential performance – Collateral standard: General requirements, tests and

guidance for alarm systems in medical electrical equipment and medical electrical systems

IEC 60601-1-8:2006/AMD1:2012
201.3 Terms and definitions
* 201.3.201
B rms

Delete, in the first line of the definition, “the MR relevant radiofrequency magnetic induction”.

Replace, in the last line of the definition, “evaluation time” with “integration time”.

Replace, in the last line of the definition “, and is estimated at the RF transmit coil centre”

with “, which shall be any 10 s period over the duration of the entire sequence”
Add the following new note to entry:

Note 1 to entry: B is derived from the flip angle averaged over an adjustment volume, which is typically

represented by the axial central slab wherein MR signal is generated.
201.3.203
CONTROLLED ACCESS AREA
Replace the existing text of the definition with the following:

area around the MR SYSTEM, to which access is controlled to prevent HARM from the magnetic

field

Note 1 to entry: The CONTROLLED ACCESS AREA is not identical to the SPECIAL ENVIRONMENT or SPECIAL LOCATION

as defined in IEC 60601-1-2:2014.
201.3.234
TIME RATE OF CHANGE OF THE MAGNETIC FIELD
dB/dt
Add, at the end of the definition, the following note to entry:

Note 1 to entry: The time rate of change of the magnetic field dB/dt is assumed to be evaluated in a suitably low

frequency range (e.g. < 5 kHz) to disregard effects of switching amplifier ripple.

Add the following new terms:
201.3.242
FIXED PARAMETER OPTION
FPO

option within existing modes (i.e. NORMAL OPERATING MODE or FIRST LEVEL CONTROLLED

OPERATING MODE), which specifies a set of operational limit values for the allowable RF field

and GRADIENT OUTPUT and the specified B of the MR EQUIPMENT in a MR EXAMINATION
---------------------- Page: 5 ----------------------
– 4 – IEC 60601-2-33:2010/AMD2:2015
© IEC 2015
201.3.243
FIXED PARAMETER OPTION:BASIC
FPO:B

“basic” denotes a specific implementation of FPO, exclusively for 1,5 T MR SYSTEMS

Note 1 to entry: The note to entry in French concerning the source of the abbreviation “FPO:B” concerns the French

text only.
201.3.244

component of the RF field in the rotating frame that is effective for tilting of the nuclear

magnetization
201.3.245
B PEAK
peak amplitude of B
* 201.3.246
(|dB/dt| PEAK)
FPO
maximum time rate of change of the magnitude of the magnetic field during the MR

EXAMINATION, evaluated at the location defined for FPO, i.e. a surface providing 5 cm clearance

to the outline of the PATIENT accessible volume
* 201.3.247
(|dB/dt| RMS)
FPO

root mean square (rms) of the magnitude of the time rate of change of the magnetic field for

FPO
x dB
FPO
| |
( )
(| | RMS) =
FPO
dt t

Where t is time, and t is the integration time. dB /dt is a conservative model estimate of

x FPO
the magnetic field associated with the switching gradients
201.3.248
SLEW PERCENTAGE
fraction of time that any gradient is slewing at any rate
201.3.249
CIRCULARLY POLARIZED RF

RF excitation where the two principal electromagnetic modes of the VOLUME RF TRANSMIT COIL

are driven with equal amplitude and 90° phase difference

Note 1 to entry: This drive operation is denoted as “CP” on user interfaces and in ACCOMPANYING DOCUMENTS.

Note 2 to entry: Circularly polarized RF is also commonly referred to as quadrature drive

* 201.3.250
SPATIAL FIELD GRADIENT
SFG
spatial rate of change of the main magnetic field , expressed in [T/m]

Note 1 to entry: Attractive magnetic forces on magnetisable or saturated ferromagnetic objects scale linearly with

SFG.
---------------------- Page: 6 ----------------------
IEC 60601-2-33:2010/AMD2:2015 – 5 –
© IEC 2015

Note 2 to entry: The note to entry in French concerning the source of the abbreviation “SFG” concerns the French

text only.
Table 201.101 – List of symbols
Replace the existing title with the following:
Table 201.101 – List of symbols and abbreviations
201.7 ME EQUIPMENT identification, marking and documents
201.7.2 Marking on the outside of ME EQUIPMENT or ME EQUIPMENT parts
201.7.2.13 Physiological effects (safety signs and warning statements)

Replace, in the first sentence of the first paragraph, ”ISO 7010-W005 and ISO 7010-W006”

with ”ISO 7010-W005 (see Table 201.D.101, safety sign 1) and ISO 7010-W006 (see Table

201.D.101, safety sign 2)”
201.7.9 ACCOMPANYING DOCUMENTS
201.7.9.2 Instructions for use
* 201.7.9.2.101 Instructions for use for MR EQUIPMENT
* d) Exposure of the PATIENT and MR WORKER to excessive acoustic noise

Add, at the end of the only sentence in Note 1, ”(see Table 201.D.101, safety sign 6)”

* f) Liquid and gaseous cryogens

Add, between the first and second bullet points under the last dash, the following new note:

NOTE Applicable safety signs ISO 7010-M004 (see Table 201.D.101, safety sign 7) and ISO 7010-M009 (see

Table 201.D.101, safety sign 8) are appropriate for placement near the location where the cryogen refill is

performed.
* h) Exposure of the PATIENT and MR WORKER to the static magnetic field
Replace, in the 4th dash, “4 T” with “8 T”.
Replace, in the 8th dash, “4 T” with “8 T”.
* t) Scanning of PATIENTs with active or passive implants.
Replace the entire text of this item with the following:

The instructions for use shall declare that MR scanning is contra-indicated for PATIENTS with

implants, the exception being PATIENTS with known MR safe or MR conditional implants that

can be scanned according to the conditions specified in the implant labelling. The instructions

for use shall describe the following RISKS associated with the scanning of PATIENTS with active

or passive implants containing metal or other magnetic and/or electrically conductive

materials:
– the electromagnetic fields might exert strong forces on such implants;

– the electromagnetic fields might interfere with the operation of active devices;

– the implants might cause significant artefacts in the MR image;
---------------------- Page: 7 ----------------------
– 6 – IEC 60601-2-33:2010/AMD2:2015
© IEC 2015

– MR scanning when an implant is present might cause HARM such as internal heating that

results in tissue damage, loss of physiologic function and serious injury.

The instructions for use shall also address the following related to MR scanning of PATIENTS

with MR conditional implants:

– the MR scan should only be conducted based on the result of a risk versus benefit

assessment by the RESPONSIBLE ORGANIZATION;

– the MR OPERATOR shall adhere to the conditions of use defined in the MR conditional

implant labelling as described in the ACCOMPANYING DOCUMENTS of the implant
MANUFACTURER;

– the instructions for use shall include a statement to explain the roles and responsibilities

of the MR MANUFACTURER, the implant MANUFACTURER and the MR OPERATOR in scanning of

PATIENTS with MR conditional implants.
NOTE 8 Sample text is provided in Annex AA
w) About function
Replace the existing text of the second dash by the following:

– Maximum SPATIAL FIELD GRADIENT of the static magnetic field [T/m] outside the FIXED

magnet covers

NOTE Historical labeling practice for MR conditional devices uses G/cm where 1 T/m is equivalent to 100 G/cm.

Providing the conversion factor and/or the quantities in both units may be appropriate.

Add, after the second dash, the following new dash:

– Maximum spatial encoding gradient amplitude [mT/m] and maximum slew rate [T/m/s],

both specified on a per axis basis
Replace the final dash with the following:

– Maximum combined GRADIENT OUTPUT [T/s] on a cylinder with a diameter of 0,2 m, 0,4 m

and bore-diameter minus 0,1 m
Add, at the end of subclause 201.7.9.2.101, the following new item:
x) FPO (FIXED PARAMETER OPTION)
If the system has FPO capabilities, the following information shall be given:

– a statement that FPO limits the gradient and RF output in terms of dB/dt and B ;

– a statement that FPO requires OPERATOR activation;
– instructions on how to activate FPO;

– a statement that FPO limits may be part of MR conditional medical device labelling and that

other scanning limits and/or PATIENT preparation may be required in addition to FPO to fully

comply with the implant device MR conditional labelling;

– a statement that FPO does not alter previously established operating modes, i.e. FPO can

work in NORMAL OPERATING MODE and FIRST LEVEL CONTROLLED OPERATING MODE;

– a statement indicating that FPO is for use with devices that have MR conditional labelling

that specifies FPO and the use of FPO when scanning PATIENTS with medical devices that

do not have FPO labelling is potentially hazardous and may cause serious injury or death.

201.7.9.3 Technical description
201.7.9.3.101 Technical description of MR EQUIPMENT
a) CONTROLLED ACCESS AREA
Replace this subtitle as follows:
---------------------- Page: 8 ----------------------
IEC 60601-2-33:2010/AMD2:2015 – 7 –
© IEC 2015
a) CONTROLLED ACCESS AREA and SPECIAL ENVIRONMENT
Replace, in the first paragraph, “permanently attached” with “FIXED magnet”.

Delete, in the same paragraph, “and/or an electromagnetic interference level that does not

comply with IEC 60601-1-2, “.

Add, at the end of the first dash, “ the static magnetic fringe field strength shall not exceed

0,5 mT;”
Delete existing items 1) and 2).
Add, in the third dash, before the words “magnetic fields”, the word “static”.
Add, after the third dash, the following new paragraph:

For those parts of the MR EQUIPMENT that require installation in a SPECIAL ENVIRONMENT, to

ensure compliance with IEC 60601-1-2:2014, the technical description shall describe the need

for adequate RF shielding, including the presence of an RF door switch and interlock

mechanism preventing undue RF emissions and immunity.
Add, after the new paragraph, the following new note:
NOTE 5 See also 202.5.2.2.2
* b) Compatibility technical specification sheet

Replace, in the third bullet under the first dash, the existing text of the first sentence with the

following:

“The position in locations outside the FIXED magnet covers where SPATIAL FIELD GRADIENT

(SFG) is maximum, and the values of B and the SFG at that location.”

Replace, in the fourth bullet under the first dash, the existing text of the first sentence with the

following:

“The position in locations outside the FIXED magnet covers where the product of the

magnitude of the static magnetic field B and the SFG is maximum and the value of B and

0 0
SFG at that location.”
201.9 Protection against MECHANICAL HAZARDS of ME EQUIPMENT and ME SYSTEMS
201.9.8 HAZARDS associated with support systems
Replace the existing title of this subclause with the following:
201.9.8 MECHANICAL HAZARDS associated with support systems
Add the following new subclause:
201.9.8.3 Strength of PATIENT or OPERATOR support or suspension systems
201.9.8.3.3 Dynamic forces due to loading from persons
Addition:

Where it is determined that the dynamic loading test of the general standard applies, the

following provides an alternative means of compliance.
---------------------- Page: 9 ----------------------
– 8 – IEC 60601-2-33:2010/AMD2:2015
© IEC 2015

NOTE 1 The mass is accelerated for 150 mm, and then decelerates during compression of the 60 mm of foam,

resulting in a force equivalent from 2 to 3 times the SAFE WORKING LOAD.

Where mechanical analysis proves that the following static load test is more severe than the

dynamic load test specified in the general standard, it is possible to waive the dynamic load

test based on RISK MANAGEMENT.
Compliance is checked by the following test:

Prior to performing this test, a PATIENT support/suspension system is positioned horizontally in

its most disadvantageous position in NORMAL USE WHERE PATIENT loading and unloading takes

place.

A mass which results in a force calculated to be greater than the dynamic load shall be placed

on the PATIENT support. The contact area of this mass is equivalent to that defined in

Figure 33 of the general standard and is applied for at least one minute. Any loss of function

or structural damage that could result in unacceptable RISK constitutes a failure.

NOTE 2 The foam described in Figure 33 of the general standard is not required for this test.

201.12 Accuracy of controls and instruments and protection against hazardous
outputs
* 201.12.4 Protection against hazardous output
201.12.4.101 Operating modes
201.12.4.101.2 All operating modes
Add, at the end of this subclause:

d) The MR EQUIPMENT shall, on request, display “CP” on the CONTROL PANEL if CIRCULARLY

POLARIZED RF is used for the scan. For systems capable of other types of driving the

VOLUME RF TRANSMIT COIL, means shall be provided to the MR OPERATOR to select

CIRCULARLY POLARIZED RF. If selected, CIRCULARLY POLARIZED RF shall be active over the

entire examination.
* 201.12.4.103 Protection against excessive radio frequency energy
* 201.12.4.103.2 Limits for SAR
Table 201.105 – SAR limits for volume transmit coils

Replace, in the 8th row, 1st column “Long MR EXAMINATION specific absorbed energy” with “MR

EXAMINATION specific absorbed energy”
Replace, in the 8th row, 2nd column, the entire text with:

“The max. energy dose (SAR × examination time) shall be limited, subject to the RISK

MANAGEMENT.”
Replace Note 3 with:

NOTE 3 The MR EXAMINATION specific absorbed energy limitation has been introduced because very long duration

PATIENT studies have become more common. It limits either the MR EXAMINATION duration or the SAR level of the

individual scans of this MR EXAMINATION and is applicable to all SAR limits and all operating modes. If there are

multiple, separate studies on a given day where the PATIENT has been given a reasonable rest, each study is

considered to be independent from a MR EXAMINATION specific absorbed energy perspective.

* 201.12.4.104 Protection against exposure to static magnetic fields
Replace, in the first paragraph of item b), “4 T” with “8 T”.
---------------------- Page: 10 ----------------------
IEC 60601-2-33:2010/AMD2:2015 – 9 –
© IEC 2015
Delete the second paragraph of item b).
Replace, in item c, “4 T” with “8 T”.

Replace, in the paragraph after item c) starting with “Physiological effects”, both instances of

“shall” with “should”.
Add the following new subclause:
* 201.12.4.106 Fixed limits to physical outputs of MR EQUIPMENT
201.12.4.106.1 General

Scanning of a PATIENT with a device which is labelled MR conditional could require controlled

outputs of the MR EQUIPMENT to less than the system capabilities. The MANUFACTURER of the

MR EQUIPMENT may implement a FIXED PARAMETER OPTION (FPO) for this purpose. If

implemented, FPO shall be designed to comply with all requirements of 201.12.4.106. FPO

shall not interfere with proper application of the evaluation and reporting of the operating

modes (see 201.12.4.101).

A system that has implemented FPO guarantees that the controlled outputs will not exceed the

specified values. The safety of an MR conditional implant labelled for FPO cannot be assessed

in a system running FPO.
201.12.4.106.2 Limit values

The following limits shall be applied to RF field and GRADIENT OUTPUT when the MR EQUIPMENT

is operated in the FPO. The set of values provided in Table 201.107 shall be called FPO:B.

NOTE 1 B denotes “basic”. This reflects the possibility to add another FPO at a later point in time with other limit

values than those defined in 201.107
Table 201.107 – FPO limits applicable for cylindrical MR SYSTEMS
Physical Parameter FPO:B
Nominal static magnetic field strength 1,5 T
Applicable coils Birdcage WHOLE BODY RF TRANSMIT COIL
Birdcage HEAD RF TRANSMIT COIL
CIRCULARLY POLARIZED RF shall be applied.
B PEAK
<= 30 µT
B RMS <= 3,2 µT
(|dB/dt| PEAK)
<= 100 T/s
FPO
(|dB/dt| RMS)
<= 56 T/s
FPO

NOTE 2 Cylindrical MR systems with elliptical PATIENT apertures can meet requirements for FPO:B.

201.12.4.106.3 User interface

The MR EQUIPMENT shall provide a means on the CONTROL PANEL to activate FPO during

PATIENT registration. While active, the user interface shall indicate that FPO is enabled and

give the FPO version (e.g. FPO:B). FPO:B will remain active for the remainder of the

examination until the next PATIENT registration.
---------------------- Page: 11 ----------------------
– 10 – IEC 60601-2-33:2010/AMD2:2015
© IEC 2015
*201.12.4.106.4 Implementation and demonstrating compliance for B PEAK

The MR EQUIPMENT shall control the value of B PEAK for each RF pulse in every sequence,

including adjustment sequences (prescan), not to exceed the values specified in Table

201.107.

Compliance is demonstrated by design review of the applied limits in the sequence pre-

calculation software, or by evaluation of pre-calculated B PEAK values for all RF pulses in

sequences developed under FPO restrictions. Compliance shall be evaluated for all adjustment

sequences intended to be used with FPO enabled. In addition, run-time hardware and/or

software checks may be used in the MR EQUIPMENT to ensure that the actual B PEAK never

exceeds the B PEAK values as specified in Table 201.107. A possible method to control

B PEAK is described in the rationale.

NOTE The spatially-localized amplitude of total B vector, especially in the off-centre position, may exceed the

nominal value of B PEAK by up to an order of magnitude.
201.12.4.106.5 Implementation and demonstrating compliance for B RMS

The MR EQUIPMENT shall control the value of B RMS for every sequence, including adjustment

sequences (e.g. prescan), not to exceed the values specified in Table 201.107.
Compliance shall be demonstrated by design review.

NOTE The spatially-localized amplitude of total B RMS vector, especially in the off-centre position, may exceed

the nominal value of B RMS by up to an order of magnitude.
201.12.4.106.6 Implementation and demonstrating compliance for (|dB/dt| PEAK)
FPO

The MR EQUIPMENT shall control the value of (|dB/dt| PEAK) whenever the gradient is

FPO

slewing, in every sequence, including adjustment sequences, not to exceed the values

specified in Table 201.107.

The values for (|dB/dt| PEAK) shall be controlled at a surface providing 5 cm clearance to

FPO
the outline of the PATIENT accessible volume.
The (|dB/dt| PEAK) value shall be calculated per sequence.
FPO
Compliance is demonstrated by application of calculation methods specified in

201.12.4.105.2.2 at the surface providing 5 cm clearance to the outline of the PATIENT

accessible volume. Based on symmetries, calculation in one octant of the gradient coil may be

sufficient to demonstrate compliance. Software validation for representative sequences shall

prove that calculated values do not exceed the value defined in Table 201.107. This can be a

measurement with a pick up coil at representative locations.
201.12.4.106.7 Implementation and demonstrating compliance for (|dB/dt| RMS)
FPO

The MR EQUIPMENT shall control the value of (|dB/dt| RMS) for every sequence, including

FPO
adjustment sequences, not to exceed the values specified in Table 201.107.The

MANUFACTURER shall select one of the following five tiers based on numerical evaluation of the

GRADIENT OUTPUT to implement control of (|dB/dt| RMS) .
FPO
a) Calculate maximum allowed SLEW PERCENTAGE using (|dB/dt| RMS) and (|dB/dt|
FPO
PEAK) from Table 201.107 where the relationship is (|dB/dt| RMS) = (|dB/dt|
FPO FPO
PEAK) *SQRT(SLEW PERCENTAGE). The MR EQUIPMENT shall ensure by evaluation of the
FPO

gradient waveforms that the actual SLEW PERCENTAGE in the sequence will not exceed the

maximum allowed SLEW PERCENTAGE.

b) Calculate peak |dB/dt| for each gradient slew using the method of 201.12.4.106.6,

determine the global maximum (|dB/dt| PEAK) of all gradient
...