IEC 60601-2-37:2007

IEC 60601-2-37
Edition 2.0 2007-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Medical electrical equipment –
Part 2-37: Particular requirements for the basic safety and essential performance
of ultrasonic medical diagnostic and monitoring equipment

Appareils électromédicaux –
Partie 2-37: Exigences particulières pour la sécurité de base et les performances
essentielles des appareils de diagnostic et de surveillance médicaux à ultrasons
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IEC 60601-2-37
Edition 2.0 2007-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
Medical electrical equipment –
Part 2-37: Particular requirements for the basic safety and essential performance
of ultrasonic medical diagnostic and monitoring equipment

Appareils électromédicaux –
Partie 2-37: Exigences particulières pour la sécurité de base et les performances
essentielles des appareils de diagnostic et de surveillance médicaux à ultrasons

INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
X
CODE PRIX
ICS 11.040.55; 17.140.50 ISBN 2-8318-9266-X

– 2 – 60601-2-37 © IEC:2007
CONTENTS
FOREWORD.4
INTRODUCTION.6

201.1 Scope, object and related standards .7
201.2 Normative references.8
201.3 Terminology and definitions .8
201.4 General requirements.11
201.5 General requirements for testing ME EQUIPMENT .12
201.6 Classification of ME EQUIPMENT and ME SYSTEMS .12
201.7 ME EQUIPMENT identification, marking and documents .12
201.8 Protection against electrical HAZARDS from ME EQUIPMENT .15
201.9 Protection against MECHANICAL HAZARDS of ME EQUIPMENT and ME SYSTEMS.16
201.10 Protection against unwanted and excessive radiation HAZARDS .16
201.11 Protection against excessive temperatures and other HAZARDS .17
201.12 Accuracy of controls and instruments and protection against hazardous
outputs .21
201.13 Hazardous situations and fault conditions .22
201.14 PROGRAMMABLE ELECTRICAL MEDICAL SYSTEMS (PEMS) .23
201.15 Construction of ME EQUIPMENT .23
201.16 ME SYSTEMS.23
201.17 *Electromagnetic compatibility of ME EQUIPMENT and ME SYSTEMS .23
202.6 ELECTROMAGNETIC COMPATIBILITY .23

Annex AA (informative) Guidance and rationale for particular subclauses .26
Annex BB (informative) Guidance in classification according to CISPR 11 .31
Annex CC (informative) Guidance to the MANUFACTURER on the interpretation of TI and
MI to be used to inform the OPERATOR.32
Annex DD (informative) Example set-up to measure surface temperature of externally
applied TRANSDUCER ASSEMBLIES .35

Bibliography.38

Index of defined terms .41

Figure DD.1 – Set-up of an example test object to measure the surface temperature of
externally applied transducers .37

Table 201.101 – List of symbols.11
Table 201.102 – Distributed essential performance requirements .12
Table 201.103 –Acoustic output reporting table .15
Table 201.104 – Overview of the tests noted under 201.11.1.3 .20
Table CC.1 – Relative importance of maintaining low exposure indices in various
scanning situations .34

60601-2-37 © IEC:2007 – 3 –
Table DD.1 – Acoustic and thermal properties of tissues & materials .35
Table DD.2 – Weight % pure components .36

– 4 – 60601-2-37 © IEC:2007
INTERNATIONAL ELECTROTECHNICAL COMMISSION
______________
MEDICAL ELECTRICAL EQUIPMENT –

Part 2-37: Particular requirements for the basic safety
and essential performance of ultrasonic medical
diagnostic and monitoring equipment

FOREWORD
1) The International Electrotechnical Commission (IEC) is a worldwide organization for standardization comprising
all national electrotechnical committees (IEC National Committees). The object of IEC is to promote
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5) IEC provides no marking procedure to indicate its approval and cannot be rendered responsible for any
equipment declared to be in conformity with an IEC Publication.
6) All users should ensure that they have the latest edition of this publication.
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8) Attention is drawn to the Normative references cited in this publication. Use of the referenced publications is
indispensable for the correct application of this publication.
9) Attention is drawn to the possibility that some of the elements of this IEC Publication may be the subject of
patent rights. IEC shall not be held responsible for identifying any or all such patent rights.
International standard IEC 60601-2-37 has been prepared by IEC subcommittee 62B:
Diagnostic imaging equipment, of IEC technical committee 62: Electrical equipment in medical
practice.
This second edition cancels and replaces the first edition published in 2001 and its
Amendment 1 (2004) and Amendment 2 (2005). This edition combines the previous edition
and its amendments into a form compatible with the parent IEC 60601-1:2005.
The text of this particular standard is based on the following documents:
Enquiry draft Report on voting
62B/624/CDV 62B/657/RVC
Full information on the voting for the approval of this particular standard can be found in the
report on voting indicated in the above table.

60601-2-37 © IEC:2007 – 5 –
This publication has been drafted in accordance with the ISO/IEC Directives, Part 2.
In this standard, the following print types are used:
– Requirements and definitions: roman type.
– Test specifications: italic type.
– Informative material appearing outside of tables, such as notes, examples and references: in smaller type.
Normative text of tables is also in a smaller type.
ERMS DEFINED IN CLAUSE 3 OF THE GENERAL STANDARD, IN THIS PARTICULAR STANDARD OR AS
– T
NOTED: SMALL CAPITALS.
In referring to the structure of this standard, the term
– “clause” means one of the seventeen numbered divisions within the table of contents,
inclusive of all subdivisions (e.g. Clause 7 includes subclauses 7.1, 7.2, etc.);
– “subclause” means a numbered subdivision of a clause (e.g. 7.1, 7.2 and 7.2.1 are all
subclauses of Clause 7).
References to clauses within this standard are preceded by the term “Clause” followed by the
clause number. References to subclauses within this particular standard are by number only.
In this standard, the conjunctive “or” is used as an “inclusive or” so a statement is true if any
combination of the conditions is true.
The verbal forms used in this standard conform to usage described in Annex H of the ISO/IEC
Directives, Part 2. For the purposes of this standard, the auxiliary verb:
– “shall” means that compliance with a requirement or a test is mandatory for compliance
with this standard;
– “should” means that compliance with a requirement or a test is recommended but is not
mandatory for compliance with this standard;
– “may” is used to describe a permissible way to achieve compliance with a requirement or
test.
An asterisk (*) as the first character of a title or at the beginning of a paragraph or table title
indicates that there is guidance or rationale related to that item in Annex AA.
A list of all parts of the IEC 60601 series, published under the general title: Medical electrical
equipment, can be found on the IEC website
The committee has decided that the contents of this publication will remain unchanged until
the maintenance result 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.
– 6 – 60601-2-37 © IEC:2007
INTRODUCTION
In this particular standard, safety requirements additional to those in the general standard are
specified for ULTRASONIC DIAGNOSTIC EQUIPMENT.
A general guidance and rationale for the requirements of this particular standard are given in
Annex AA.
Knowledge of the reasons for these requirements will not only facilitate the proper application
of this particular standard but will, in due course, expedite any revision necessitated by
changes in clinical practice or as a result of developments in technology.
The approach and philosophy used in drafting this particular standard for safety of
ULTRASONIC DIAGNOSTIC EQUIPMENT are consistent with those in standards of the
IEC 60601-2-xx series that apply to other diagnostic modalities, such as X-ray equipment and
magnetic resonance systems.
In each case, the safety standard is intended to require increasing sophistication of output
display indicators and/or controls with increasing energy levels in the interrogating field of
diagnosis. Thus, for all such diagnostic modalities, it is the responsibility of the OPERATOR to
understand the risk of the output of the ULTRASONIC DIAGNOSTIC EQUIPMENT, and to act
appropriately in order to obtain the needed diagnostic information with the minimum risk to the
PATIENT.
60601-2-37 © IEC:2007 – 7 –
MEDICAL ELECTRICAL EQUIPMENT –

Part 2-37: Particular requirements for the basic safety
and essential performance of ultrasonic medical
diagnostic and monitoring equipment

The clauses and subclauses of the general standard apply except as follows:
201.1 Scope, object and related standards
Clause 1 of the general standard applies, except as follows:
201.1.1 *Scope
Addition:
This International Standard applies to the BASIC SAFETY and ESSENTIAL PERFORMANCE of
ULTRASONIC DIAGNOSTIC EQUIPMENT as defined in 201.3.217, hereinafter referred to as ME
EQUIPMENT.
If a clause or subclause is specifically intended to be applicable to ME EQUIPMENT only, or to
ME SYSTEMS only, the title and content of that clause or subclause will say so. If that is not the
case, the clause or subclause applies both to ME EQUIPMENT and to ME SYSTEMS, as relevant.
HAZARDS inherent in the intended physiological function of ME EQUIPMENT or ME SYSTEMS
within the scope of this standard are not covered by specific requirements in this standard
except in 7.2.13 and 8.4.1 of this standard.
NOTE See also subclause 4.2 of this standard.
This particular standard does not cover ultrasonic therapeutic equipment. Equipment used for
the imaging or diagnosis of body structures by ultrasound in conjunction with other medical
procedures is covered.
201.1.2 Object
Replacement:
The object of this particular standard is to establish particular BASIC SAFETY and ESSENTIAL
PERFORMANCE requirements for ULTRASONIC DIAGNOSTIC EQUIPMENT as defined in 201.3.217.
201.1.4 Particular standards
Replacement:
In the IEC 60601 series, particular standards may modify, replace or delete requirements
contained in the general standard as appropriate for the particular ME EQUIPMENT under
consideration, and may add other BASIC SAFETY and ESSENTIAL PERFORMANCE requirements.
A requirement of a particular standard takes priority over the general standard.

– 8 – 60601-2-37 © IEC:2007
For brevity, IEC 60601-1 is referred to in this particular standard as the general standard.
Collateral standards are referred to by their document number.
The numbering of sections, clauses and subclauses of this particular standard corresponds to
that of the general standard with the prefix “201” (e.g. 201.1 in this particular standard
addresses the content of Clause 1 of the general standard) or applicable collateral standard
with the prefix “20x” where x is the final digit(s) of the collateral standard document number
(e.g. 202.6 in this particular standard addresses the content of Clause 6 of the 60601-1-2
collateral standard, 203.4 in this particular standard addresses the content of Clause 4 of the
60601-1-3 collateral standard, etc.). The changes to the text of the general standard are
specified by the use of the following words:
"Replacement" means that the clause or subclause of the general standard or applicable
collateral standard is replaced completely by the text of this particular standard.
"Addition" means that the text of this particular standard is additional to the requirements of
the general standard or applicable collateral standard.
"Amendment" means that the clause or subclause of the general standard or applicable
collateral standard is amended as indicated by the text of this particular standard.
Subclauses, figures or tables which are additional to those of the general standard are
numbered starting from 201.101, additional annexes are lettered AA, BB, etc., and additional
items aa), bb), etc.
Subclauses or figures which are additional to those of a collateral standard are numbered
starting from 20x, where “x” is the number of the collateral standard, e.g. 202 for IEC 60601-
1-2, 203 for IEC 60601-1-3, etc.
The term "this standard" is used to make reference to the general standard, any applicable
collateral standards and this particular standard taken together.
Where there is no corresponding section, clause or subclause in this particular standard, the
section, clause or subclause of the general standard or applicable collateral standard,
although possibly not relevant, applies without modification; where it is intended that any part
of the general standard or applicable collateral standard, although possibly relevant, is not to
be applied, a statement to that effect is given in this particular standard.
201.2 Normative references
Clause 2 of the general standard applies except as follows:
Addition:
IEC 62359, Ultrasonics – Field characterization – Test methods for the determination of
thermal and mechanical indices related to medical diagnostic ultrasonic fields
201.3 Terminology and definitions
For the purposes of this document, the terms and definitions given in the general standard
and in IEC 62359, as well as the following additions apply:
NOTE 1 An index of defined terms is given after the Bibliography.
NOTE 2 A list of symbols used in this particular standard is found in Table 201.101.

60601-2-37 © IEC:2007 – 9 –
201.3.201
BONE THERMAL INDEX
THERMAL INDEX for applications, such as foetal (second and third trimester) or neonatal
cephalic (through the fontanelle) applications, in which the ultrasound beam passes through
soft tissue and there is bone close to a focal region
Symbol: TIB
Unit: None
NOTE See IEC 62359 for methods of determining the BONE THERMAL INDEX.
201.3.202
COMBINED-OPERATING MODE
mode of operation of ULTRASONIC DIAGNOSTIC EQUIPMENT that combines more than one

DISCRETE-OPERATING MODE
201.3.203
CRANIAL-BONE THERMAL INDEX
THERMAL INDEX for applications, such as paediatric and adult cranial applications, in which the
ultrasound beam passes through bone near the beam entrance into the body
Symbol: TIC
Unit: None
NOTE See IEC 62359 for methods of determining the CRANIAL-BONE THERMAL INDEX
201.3.204
DEFAULT SETTING
specific state of control the ULTRASONIC DIAGNOSTIC EQUIPMENT will enter upon power-up, new
PATIENT select, or change from non-foetal to foetal applications
201.3.205
DISCRETE-OPERATING MODE
mode of operation of ULTRASONIC DIAGNOSTIC EQUIPMENT in which the purpose of the excitation
of the ULTRASONIC TRANSDUCER or ULTRASONIC TRANSDUCER element group is to utilise only
one diagnostic methodology
201.3.206
FULL SOFTWARE CONTROL OF ACOUSTIC OUTPUT
means by which the ULTRASONIC DIAGNOSTIC EQUIPMENT manages the acoustic output
independent of direct OPERATOR control
201.3.207
INVASIVE TRANSDUCER ASSEMBLY
a transducer which, in whole or in part, penetrates inside the body, either through a body
orifice or through the surface of the body
201.3.208
MECHANICAL INDEX
the displayed parameter representing potential cavitation bioeffects
Symbol: MI
Unit: None
NOTE See IEC 62359 for methods of determining the MECHANICAL INDEX.
201.3.209
MULTI-PURPOSE ULTRASONIC DIAGNOSTIC EQUIPMENT
ULTRASONIC DIAGNOSTIC EQUIPMENT that is intended for more than one clinical application

– 10 – 60601-2-37 © IEC:2007
201.3.210
NON-SCANNING MODE
mode of operation of ULTRASONIC DIAGNOSTIC EQUIPMENT that involves a sequence of
ultrasonic pulses that give rise to ultrasonic scan lines that follow the same acoustic path
201.3.211
PRUDENT USE STATEMENT
affirmation of the principle advising avoidance of high exposure levels and long exposure
times while acquiring only information which is clinically required
201.3.212
SCANNING MODE
mode of operation of ULTRASONIC DIAGNOSTIC EQUIPMENT that involves a sequence of
ultrasonic pulses that give rise to scan lines that do not follow the same acoustic path
201.3.213
SOFT TISSUE THERMAL INDEX
THERMAL INDEX related to soft tissues
Symbol: TIS
Unit: None
NOTE 1 See IEC 62359 for methods of determination of the SOFT-TISSUE THERMAL INDEX.
NOTE 2 For the purposes of this document, “soft tissue“ includes all body tissues and fluids but excludes skeletal
tissues.
201.3.214
THERMAL INDEX
ratio of attenuated acoustic power at a specified point to the attenuated acoustic power
required to raise the temperature at that point in a specific tissue model by 1 °C.
Symbol: TI
Unit: None
NOTE See IEC 62359 for methods of determining the THERMAL INDEX
201.3.215
TRANSDUCER ASSEMBLY
the transducer housing (probe), any associated electronic circuitry, the active ultrasonic
transducer module, and any liquids contained in the housing and the integral cable that
connects the transducer probe to an ultrasound console
201.3.216
TRANSMIT PATTERN
combination of a specific set of transducer beam-forming characteristics (determined by the
transmit aperture size, apodisation shape, and relative timing/phase delay pattern across the
aperture, resulting in a specific focal length and direction), and an electrical drive waveform of
a specific fixed shape but variable amplitude
201.3.217
ULTRASONIC DIAGNOSTIC EQUIPMENT
MEDICAL ELECTRICAL EQUIPMENT that is intended for ultrasonic medical examination
201.3.218
ULTRASONIC TRANSDUCER
device capable of converting electrical energy to mechanical energy and/or mechanical
energy to electrical energy, both within the ultrasonic frequency range

60601-2-37 © IEC:2007 – 11 –
Table 201.101 – List of symbols
Symbol Term Reference
A = -12dB OUTPUT BEAM AREA IEC 62359, 3.25
aprt
d = EQUIVALENT BEAM DIAMETER IEC 62359, 3.22
eq
f = ACOUSTIC WORKING FREQUENCY IEC 62359, 3.2
awf
I = ATTENUATED PULSE-AVERAGE INTENSITY IEC 62359, 3.5
pa,α
I = PULSE-INTENSITY INTEGRAL IEC 62359, 3.32
pi
I = ATTENUATED PULSE-INTENSITY INTEGRAL IEC 62359, 3.6
pi,α
I = SPATIAL-PEAK TEMPORAL-AVERAGE INTENSITY IEC 62359, 3.38
spta
I (z) = ATTENUATED TEMPORAL-AVERAGE INTENSITY IEC 62359, 3.8
ta, α
MI = MECHANICAL INDEX IEC 62359, 3.23
P = OUTPUT POWER IEC 62359, 3.27
P = ATTENUATED OUTPUT POWER IEC 62359, 3.3
α
P = ATTENUATED PEAK-RAREFACTIONAL ACOUSTIC PRESSURE IEC 62359, 3.4
r,α
P = PEAK-RAREFACTIONAL ACOUSTIC PRESSURE IEC 62359, 3.28
r
prr = PULSE REPETITION RATE IEC 62359, 3.34
TI = THERMAL INDEX IEC 62359, 3.41
TIB = BONE THERMAL INDEX IEC 62359, 3.11
TIC = CRANIAL-BONE THERMAL INDEX IEC 62359, 3.15
TIS = SOFT-TISSUE THERMAL INDEX IEC 62359, 3.37
t = PULSE DURATION IEC 62359, 3.31
d
X, Y = -12dB OUTPUT BEAM DIMENSIONS IEC 62359, 3.26
z = DEPTH FOR BONE THERMAL INDEX IEC 62359, 3.17
b
z = BREAK-POINT DEPTH IEC 62359, 3.13
bp
z = DEPTH FOR SOFT-TISSUE THERMAL INDEX IEC 62359, 3.18
s
201.4 General requirements
Clause 4 of the general standard applies except as follows:
201.4.3 ESSENTIAL PERFORMANCE
Addition:
201.4.3.101 Additional ESSENTIAL PERFORMANCE requirements
Table 201.102 lists the potential sources of unacceptable risk identified to characterize the
ESSENTIAL PERFORMANCE of ULTRASONIC DIAGNOSTIC EQUIPMENT and the subclauses in which
the requirements are found.
– 12 – 60601-2-37 © IEC:2007
Table 201.102 – Distributed essential performance requirements
Requirement Subclause
Free from noise on a waveform or artefacts or distortion in an image or error of a displayed
numerical value which cannot be attributed to a physiological effect and which may alter the 202.6.2.1.10
diagnosis.
Free from the display of incorrect numerical values associated with the diagnosis to be
202.6.2.1.10
a
performed .
201.12.4.2
a
Free from the display of incorrect safety-related indications.
202.6.2.1.10
201.10.101
Free from the production of unintended or excessive ultrasound output.
202.6.2.1.10
Free from the production of unintended or excessive TRANSDUCER ASSEMBLY surface
202.6.2.1.10
temperature.
Free from the production of unintended or uncontrolled motion of TRANSDUCER ASSEMBLIES
202.6.2.1.10
intended for intra-corporeal use.
a
“incorrect” in the sense that the displayed value differs from what is calculated (having been altered during data
transfer), or the calculation itself is not correct.

NOTE In some circumstances the need for the repetition of an ultrasound examination should be evaluated as a
potential hazard, for example, intra-corporeal investigation and stress testing for cardiopathic PATIENTS.
201.5 General requirements for testing ME EQUIPMENT
Clause 5 of the general standard applies.
201.6 Classification of ME EQUIPMENT and ME SYSTEMS
Clause 6 of the general standard applies.
201.7 ME EQUIPMENT identification, marking and documents
Clause 7 of the general standard applies, except as follows:
201.7.2.9 IP classification
Addition:
If the specified IPX classification is applicable for only part of the TRANSDUCER ASSEMBLY, the
marking of the IPX code on the TRANSDUCER ASSEMBLY is not required.
201.7.2.13 *Physiological effects (safety signs and warning statements)
Addition:
A description of the means used to limit the surface heating of INVASIVE TRANSDUCER
ASSEMBLIES to no more than 43 °C in the event of a SINGLE FAULT CONDITION shall be provided
in accordance with the requirements of Clause 12.
201.7.2.101 *Acoustic output
For ULTRASONIC DIAGNOSTIC EQUIPMENT capable of generating output levels subject to
201.12.4.2 and which allows the OPERATOR to directly vary the output levels, the effect of

60601-2-37 © IEC:2007 – 13 –
adjusting the control which varies the output level shall be clear. The marking shall be of the
nature of an active display.
A display of THERMAL INDEX and MECHANICAL INDEX shall be provided in accordance with the
requirements of Clause 201.12, together with the declaration of accuracy described in 201.7.9
and Clause 201.12.
A display relevant to ultrasound output levels (Clause 201.12) shall be clearly visible from the
OPERATOR’S position, with the full name(s) or abbreviation(s) of the index (indices) displayed.
201.7.9.2.2 *Warning and safety notices
Addition:
For ULTRASONIC DIAGNOSTIC EQUIPMENT capable of generating output levels subject to Clause
201.12, information shall be provided to the OPERATOR on how to interpret the displayed
ultrasonic exposure parameters, THERMAL INDEX (TI) and MECHANICAL INDEX (MI) according to
the guidance given in Annex CC.
The procedures necessary for safe operation shall be provided, drawing attention to the
safety hazards that may occur as a result of an inadequate electrical installation when the
APPLIED PART of the ULTRASONIC DIAGNOSTIC EQUIPMENT is a TYPE B APPLIED PART.
Instruction on the safe use of TRANSDUCER ASSEMBLIES shall be provided, and, in particular,
instructions to ensure that the ULTRASONIC DIAGNOSTIC EQUIPMENT is of the correct type for its
intended application; for TRANSDUCER ASSEMBLIES intended for intra-corporeal use, a warning
in the instructions not to activate the TRANSDUCER ASSEMBLY outside the PATIENT’S body if the
TRANSDUCER ASSEMBLY, when so activated, would not comply with electromagnetic compliance
requirements and may cause harmful interference with other equipment in the environment.
The identification of interference with other equipment and mitigation techniques shall be
included in the ACCOMPANYING DOCUMENTS if the MANUFACTURER claims a reduction in test
levels.
A notice shall be provided if the ULTRASONIC DIAGNOSTIC EQUIPMENT or parts thereof are
provided with protective means against burns to the PATIENT when used with high frequency
(HF) surgical equipment. If no such means are incorporated, notice shall be given in the
ACCOMPANYING DOCUMENTS and advice shall be given regarding the location and use of the
TRANSDUCER ASSEMBLY to reduce the hazard of burns in the event of a defect in the HF
surgical neutral electrode connection.
A PRUDENT USE STATEMENT shall be provided for ULTRASONIC DIAGNOSTIC EQUIPMENT capable of
generating output levels subject to 201.12.4.2.
Descriptions shall be provided of any display or means relevant to ultrasound output by which
the OPERATOR may modify the operation of the ULTRASONIC DIAGNOSTIC EQUIPMENT. These
descriptions shall be in a separate section.
A description of any display or means by which the OPERATOR may modify the operation of the
ULTRASONIC DIAGNOSTIC EQUIPMENT relevant to surface temperature for INVASIVE TRANSDUCER
ASSEMBLIES intended for trans-oesophageal use shall be provided.
A description of those parts of the TRANSDUCER ASSEMBLY that are permitted to be immersed in
water or other liquids either for NORMAL USE or performance assessment purposes shall be
provided.
A recommendation calling the OPERATOR’S attention to the need for regular testing and
periodic maintenance including inspection of the TRANSDUCER ASSEMBLY for cracks that allow
the ingress of conductive fluid shall be provided.

– 14 – 60601-2-37 © IEC:2007
Instructions shall be provided regarding the avoidance of unintended control settings and
acoustic output levels.
Output limits selected according to 201.12.4.5.1 shall be declared in the ACCOMPANYING
DOCUMENTS. For MULTI-PURPOSE ULTRASONIC DIAGNOSTIC EQUIPMENT the output limits shall be
declared for each application.
201.7.9.2.10 Messages
Replacement of the first paragraph:
The instructions for use shall list all system messages, error messages and fault messages
that are generated and are visible to the OPERATOR, unless these messages are self-
explanatory.
201.7.9.2.12 Cleaning, disinfection and sterilization
Addition:
After first dashed item, add:
NOTE This list of parameters is neither exhaustive nor mandatory.
After second dashed item, add:
− a list of the pertinent parts, components and/or functions that should be checked after
each cleaning, disinfection or sterilization cycle, and method(s) of inspection.
201.7.9.3 Technical description
Addition:
201.7.9.3.101 Technical data regarding acoustic output levels (see also Table 201.103)
For each mode, provide the maximum value of each THERMAL and MECHANICAL INDEX (as well
as the associated parameters listed for the operating condition resulting in the maximum
index value), for which the operating mode in question is the largest (or sole) contributor.
For a TRANSDUCER ASSEMBLY and ultrasound instrument console that satisfies all of the
exemption conditions cited in 201.12.4.2 a) and b), information declared in the ACCOMPANYING
DOCUMENTS shall state that the THERMAL INDICES and the MECHANICAL INDEX are below 1,0 for
all device settings.
60601-2-37 © IEC:2007 – 15 –
Table 201.103 –Acoustic output reporting table
TIS TIB
Index label MI Non-scan Non- TIC
Scan
A > 1 cm scan
A ≤ 1 cm aprt
aprt
Maximum index value
9 9 9 9 9 9
p
r,α
P
9 9 9 9
min of [P (z ),I (z )]
α s ta,α s
z
s
zbp
Associated
acoustic para-
z
b 9
meters
z at max I
pi α
d (z )
eq b
f
awf
9 9 9 9 9 9
Dim of A X
aprt
9 9 9 9 9
Y
9 9 9 9 9
t
d 9
prr
p at max I
r pi
Other
d at max I
eq pi
information
I at max MI
pi α
FL
x 9 9
Focal
Length
FL
y
9 9
Control 1
9 9 9 9 9 9
Operating
Control 2
9 9 9 9 9 9
control
conditions
Control 3
9 9 9 9 9 9
… … … … … … …
NOTE 1 Data should only be entered in one of the columns related to TIS
NOTE 2 Information need not be provided regarding TIC for any TRANSDUCER ASSEMBLY not intended for transcranial
or neonatal cephalic uses
NOTE 3 If the requirements of 201.12.4.2a) are met, it is not required to enter any data in the columns related to TIS,
TIB or TIC.
NOTE 4 If the requirements of 201.12.4.2b) are met, it is not required to enter any data in the column related to MI.
NOTE 5 Focal Length is a NOMINAL value
NOTE 6 “9” indicates cells where a numerical value should be entered

201.8 Protection against electrical HAZARDS from ME EQUIPMENT
Clause 8 of the general standard applies except as follows:

– 16 – 60601-2-37 © IEC:2007
201.8.7.4.7 Measurement of the PATIENT LEAKAGE CURRENT
Addition:
aa) For testing the TRANSDUCER ASSEMBLIES, the APPLIED PART shall be immersed in a 0,9 %
saline solution.
201.8.7.4.8 Measurement of the PATIENT AUXILIARY CURRENT
Addition:
For testing the TRANSDUCER ASSEMBLIES, the APPLIED PART shall be immersed in a 0,9 % saline
solution.
201.8.8.3 Dielectric strength
Addition:
aa) For testing the TRANSDUCER ASSEMBLIES, the APPLIED PART shall be immersed in a 0,9 %
saline solution.
201.8.9.3.4 Thermal cycling
Addition, at the end of the first paragraph::
and, for ultrasonic transducer assemblies only, where T is
– 10 °C above the maximum allowable temperature specified in the ACCOMPANYING
DOCUMENTS for cleaning, disinfection, sterilization, normal use or storage.
201.8.10.4 Cord-connected HAND-HELD parts and cord-connected foot-operated control
devices
Addition:
This subclause does not apply to ULTRASONIC TRANSDUCER ASSEMBLIES.
201.9 Protection against MECHANICAL HAZARDS of ME EQUIPMENT and ME SYSTEMS
Clause 9 of the general standard applies.
201.10 Protection against unwanted and excessive radiation HAZARDS
Clause 10 of the general standard applies except as follows:
Additional subclause:
201.10.101 *Ultrasonic energy
The MANUFACTURER shall address the RISKS associated with ultrasonic energy in the RISK
MANAGEMENT PROCESS as described in the text of this standard.
Compliance is checked by inspection of the RISK MANAGEMENT FILE.

60601-2-37 © IEC:2007 – 17 –
Acoustic output shall be switched off when the signal acquisition is stopped (i.e.: the "freeze"
feature is enabled).
201.11 Protection against excessive temperatures and other HAZARDS
Clause 11 of the general standard applies, except as follows:
201.11.1.2.2 *APPLIED PARTS not intended to supply heat to the PATIENT
Addition:
TRANSDUCER ASSEMBLIES applied to the PATIENT shall have a PATIENT contact surface
temperature not exceeding 43 °C in NORMAL CONDITIONS when measured under test conditions
201.11.1.3.1.1.
TRANSDUCER ASSEMBLIES applied to the PATIENT shall have a PATIENT contact surface
temperature not exceeding 50 °C when measured under test conditions 201.11.1.3.1.2.
Compliance is checked by operation of the ULTRASONIC DIAGNOSTIC EQUIPMENT and
temperature tests as described in 201.11.1.3.
NOTE PATIENT contact surface includes any part of the APPLIED PART, not just the radiating surface.
201.11.1.3 *Measurements
Amendment:
Replace the third paragraph and the remaining text of the subclause with the following:
Compliance with the requirements of 11.1.1 and 11.1.2 is checked by inspection of the RISK
MANAGEMENT FILE.
201.11.1.3.1 Test conditions
The TRANSDUCER ASSEMBLY shall be tested under the following conditions:
201.11.1.3.1.1 Simulated use
The APPLIED PART of the TRANSDUCER ASSEMBLY shall be coupled acoustically to, and be
initially in thermal equilibrium with, a test object such that the ultrasound emitted from the
active surface of the TRANSDUCER ASSEMBLY enters the test object.
The positioning, and heating or cooling of the TRANSDUCER ASSEMBLY shall resemble those
corresponding to the intended application of that TRANSDUCER ASSEMBLY. This includes using a
typical amount of ultrasound coupling medium appropriate to the intended application.
The temperature shall be measured at the point on the APPLIED PART of the ULTRASONIC
TRANSDUCER ASSEMBLY that contacts the PATIENT during NORMAL USE and where the
temperature is a maximum.
The test object shall have thermal and acoustical properties mimicking those of an
appropriate tissue. In the case where the TRANSDUCER ASSEMBLY is intended for external use
this test object shall account for a skin layer.
For soft tissue, the material of the test object shall have the following properties:

– 18 – 60601-2-37 © IEC:2007
• specific heat capacity: (3 500 ± 500) J/(kg⋅K);
;
• thermal conductivity: (0,5 ± 0,1) W/(m⋅K)
• attenuation at 5 MHz: (2,5 ± 1,0) dB/cm.
NOTE 1 A general guidance for the acoustic properties of appropriate tissue is given in ICRU report 61[26] .
NOTE 2 As heat develops differently in tissue surfaces containing skin, bone or soft tissue, careful consideration
should be given to the choice of the model in relation to the intended use of the APPLIED PART. Additional guidance
can be found in Annex DD and ref [32].
The test object shall be designed (for example, using acoustic absorbers) to reduce heating
the surface of the TRANSDUCER ASSEMBLY by minimizing ultrasound reflections.
201.11.1.3.1.1.1 Test methods
Test method a) or b) specified below shall be selected.
Test method a) shall be used where the ULTRASOUND DIAGNOSTIC EQUIPMENT uses a closed
loop temperature monitoring system, as the use of test method b) could result in inappropriate
results.
a) Test criteria based on test object near human temperatures.
For TRANSDUCER ASSEMBLIES intended for external use, the initial temperature of the
surface of the test object at the object-transducer interface shall be not less than
33 °C and the ambient temperature shall be 23 °C ± 3 °C.
For INVASIVE TRANSDUCER ASSEMBLIES, the initial temperature of the surface of the test
object material at the object-transducer interface shall be not less than 37 °C and the
ambient temperature shall be 23 °C ± 3 °C.
To meet the requirements of this test, the temperature of the surface of the APPLIED PART
shall not exceed 43 °C.
b) Test criteria based upon temperature rise measurements
The ambient temperature shall be 23 °C ± 3 °C. For TRANSDUCER ASSEMBLIES intended for
external use, the initial temperature of the surface of the test object at the object-
transducer interface shall be between 20°C and 33°C, and the surface temperature rise of
the APPLIED PART shall not exceed 10 °C. For INVASIVE TRANSDUCER ASSEMBLIES, the initial
temperature of the surface of the test object at the object-transducer interface shall be
between 20°C and 37°C, and the surface temperature rise shall not exceed 6 °C.
For TRANSDUCER ASSEMBLIES intended for external use, the temperature measured under the
test conditions of 201.11.1.3.1.1 shall be equal to the sum of 33 °C plus the measured
temperature rise.
For INVASIVE TRANSDUCER ASSEMBLIES, the temperature measured under th
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