IEC 60601-2-44:2009/AMD1:2012
(Amendment)Amendment 1 - Medical electrical equipment - Part 2-44: Particular requirements for the basic safety and essential performance of X-ray equipment for computed tomography
Amendment 1 - Medical electrical equipment - Part 2-44: Particular requirements for the basic safety and essential performance of X-ray equipment for computed tomography
Amendement 1 - Appareils électromédicaux - Partie 2-44: Exigences particulières pour la sécurité de base et les performances essentielles des équipements à rayonnement X de tomodensitométrie
S'applique aux résistances fixes de dissipation supérieure à 1 W et inférieure à 1 000 W, pourvues d'un revêtement protecteur. Prescrit les valeurs préférentielles de caractéristiques. Choisit, dans la CEI 115-1, les procédures d'assurance de la qualité et les méthodes d'essai et de mesure appropriées. Fixe les exigences générales.
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IEC 60601-2-44
®
Edition 3.0 2012-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
AMENDMENT 1
AMENDEMENT 1
Medical electrical equipment –
Part 2-44: Particular requirements for the basic safety and essential performance
of X-ray equipment for computed tomography
Appareils électromédicaux –
Partie 2-44: Exigences particulières pour la sécurité de base et les performances
essentielles des équipements à rayonnement X de tomodensitométrie
IEC 60601-2-44:2009/A1:2012
---------------------- Page: 1 ----------------------
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---------------------- Page: 2 ----------------------
IEC 60601-2-44
®
Edition 3.0 2012-08
INTERNATIONAL
STANDARD
NORME
INTERNATIONALE
colour
inside
AMENDMENT 1
AMENDEMENT 1
Medical electrical equipment –
Part 2-44: Particular requirements for the basic safety and essential performance
of X-ray equipment for computed tomography
Appareils électromédicaux –
Partie 2-44: Exigences particulières pour la sécurité de base et les performances
essentielles des équipements à rayonnement X de tomodensitométrie
INTERNATIONAL
ELECTROTECHNICAL
COMMISSION
COMMISSION
ELECTROTECHNIQUE
PRICE CODE
INTERNATIONALE
CODE PRIX U
ICS 11.040.50 ISBN 978-2-83220-304-0
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 – 60601-2-44 Amend.1 © IEC:2012
FOREWORD
This amendment has been prepared by subcommittee SC 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/879/FDIS 62B/890/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.
NOTE The attention of National Committees is drawn to the fact that equipment MANUFACTURERS and testing
organizations may need a transitional period following publication of a new, amended or revised IEC publication in
which to make products in accordance with the new requirements and to equip themselves for conducting new or
revised tests. It is the recommendation of the committee that the content of this publication be adopted for
implementation nationally not earlier than 3 years from the date of publication.
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.
_____________
---------------------- Page: 4 ----------------------
60601-2-44 Amend.1 © IEC:2012 – 3 –
Introduction to Amendment 1
The main topic addressed in this amendment is an extended concept of CTDI to
accommodate CT SCANNERS with very large z-coverage. The other principal subject areas
include:
1) a dose-check feature associated with a pre-scanning alert if expected values of dose
DOSE NOTIFICATION VALUES or DOSE ALERT VALUES and
indices exceed user-configurable
2) requirements covering the use of CT data in radiotherapy treatment planning (RTP).
The CT dose metric in use has been based on the CTDI , i.e. measurement of dose in
100
PHANTOMs and limited integration of scattered radiation, and it is used in many countries’
legislation to define "dose reference values" (also called "diagnostic reference levels") for CT
examinations. Many people use these indices, CTDI and DLP, to derive estimates for
vol
is also part of CT acceptance and constancy
effective dose via conversion factors. CTDI
100
testing. The introduction of a new dose index would change all CT SCANNERS’ CTDI values.
Therefore the intention is to stay with the CTDI , i.e. the integration of primary radiation and
100
scatter over 100 mm, but adapt the way of measuring and reporting the dose index to
incorporate large collimations and to rate all collimations the same way, i.e. to reflect
approximately the same percentage of CTDI for all collimations.
∞
As defined in the amendment, CTDI is to be measured only for collimations up to 40 mm
100
with the current equipment, i.e. the PMMA PHANTOMs and a 100-mm chamber, or other
suitable methods that use a RADIATION DETECTOR. For these collimations there is no significant
change of the ratio CTDI / CTDI according to published data. For larger collimations at
100 ∞
the same CT CONDITIONS OF OPERATION, the z-efficiency may be different and must be
evaluated in the dose measurement. This can be accomplished by the measurement of dose
and the CTDI have been refined. Both
‘free air’. Based on these considerations CTDI
100 free air
types of measurement are combined now to determine the CTDI values for larger collimations
and they are explained in detail in informative Annexes CC and DD.
Some additional requirements and refinements related to dose have been added: CTDI and
vol
DLP are defined for a new type of scan mode (‘shuttle mode’). In body CT EXAMINATION it is
clarified that the CTDI and DLP always be reported for the 32-cm diameter PHANTOM. In the
vol
SCANNERS support user-configurable DOSE NOTIFICATION
amendment it is now required that CT
VALUES and DOSE ALERT VALUES.
A new subject area in this Amendment 1 covers requirements for CT SCANNERS providing
images for radiotherapy treatment planning. With this amendment begins the implementation
of this important CT application into the CT safety standard with a set of requirements that is
considered to be safety relevant. It mainly covers scanner hardware adjustments, accuracy of
CT image data, and the conversion of HU to electron and mass density.
---------------------- Page: 5 ----------------------
– 4 – 60601-2-44 Amend.1 © IEC:2012
201.1.1 Scope
Add the following new sentence:
The scope of this International Standard excludes RADIOTHERAPY SIMULATORS and systems
where the image is created by a source other than an X-RAY TUBE.
201.1.3 Collateral standards
Replace the existing text of this subclause with the following:
Addition:
This particular standard refers to those applicable collateral standards that are listed in
Clause 2 of the general standard and Clause 201.2 of this particular standard.
IEC 60601-1-2 and IEC 60601-1-3 apply as modified in Clauses 202 and 203. IEC 60601-1-8,
1) 2) 3)
IEC 60601-1-9, IEC 60601-1-10 , IEC 60601-1-11 and IEC 60601-1-12 do not apply. All
other published collateral standards in the IEC 60601-1 series apply as published.
For collateral standards published after this particular standard, MANUFACTURERS need to
determine the applicability in accordance with the RISK MANAGEMENT PROCESS.
201.2 Normative references
Add, under "Replacement", the following new reference:
IEC 60601-1-2:2007, Medical electrical equipment – Part 1-2: General requirements for basic
safety and essential performance – Collateral standard: Electromagnetic compatibility –
Requirements and tests
Add, under "Addition", the following new reference:
IEC 60336 Medical electric equipment – X-Ray Tube assemblies for medical diagnosis –
Characteristics of focal spots
201.3 Terms and definitions
201.3.202
CT CONDITIONS OF OPERATION
Add a note 3 to this definition:
NOTE 3 CT CONDITIONS OF OPERATION include parameters that are derived by the system from the user-selectable
parameters.
___________
1)
IEC 60601-1-10, Medical electrical equipment – Part 1-10: General requirements for basic safety and essential
performance – Collateral Standard: Requirements for the development of physiologic closed-loop controllers
2)
IEC 60601-1-11, Medical electrical equipment – Part 1-11: General requirements for basic safety and essential
performance – Collateral Standard: Requirements for medical electrical equipment and medical electrical
systems used in the home healthcare environment
3)
IEC 60601-1-12, Medical electrical equipment – Part 1-12: General requirements for basic safety and essential
performance – Collateral Standard: Requirements for medical electrical equipment and medical electrical
systems intended to be used in the emergency medical services environment
---------------------- Page: 6 ----------------------
60601-2-44 Amend.1 © IEC:2012 – 5 –
201.3.203
COMPUTED TOMOGRAPHY DOSE INDEX 100
CTDI
100
Replace the existing text of the definition by the following:
integral of the DOSE PROFILE representative of a single axial scan along a line perpendicular to
the TOMOGRAPHIC PLANE divided by N x T according to the following:
for N × T less than or equal to 40 mm
+50 mm
D (z)
= dz
CTDI
100
∫
N × T
−50 mm
for N × T greater than 40 mm (all CT CONDITIONS OF OPERATION except collimation are kept the
same for these measurements)
+50 mm
CTDI
D (z)
Ref free air, N×T
= dz ×
CTDI100
∫
(N ×T) CTDI
Ref free air, Ref
−50 mm
where
D(z) is the DOSE PROFILE representative of a single axial scan along a line z
perpendicular to the TOMOGRAPHIC PLANE, where dose is reported as
ABSORBED DOSE in air and is evaluated within a polymethylmethacrylate
PHANTOM (see 203.108);
(PMMA) dosimetry
(N × T) is a specific N × T of 20 mm or the largest N × T available not greater than
Ref
20 mm;
D (z) is the DOSE PROFILE representative of a single axial scan along a line z
Ref
perpendicular to the TOMOGRAPHIC PLANE, where dose is reported as
ABSORBED DOSE in air and is evaluated within a polymethylmethacrylate
(PMMA) dosimetry PHANTOM (see 203.108) for (N × T) ;
Ref
CTDI is the CTDI (201.3.215) for a specific value of N × T;
free air, N × T free air
CTDI is the CTDI (201.3.215) for (N × T) ;
free air, Ref free air Ref
N is the number of TOMOGRAPHIC SECTIONS produced in a single axial scan of
the X-ray source;
T is the NOMINAL TOMOGRAPHIC SECTION THICKNESS.
NOTE 1 The dose is reported as ABSORBED DOSE to air, but for practical purposes the evaluation of ABSORBED
DOSE to air within a PMMA dosimetry PHANTOM is well approximated by measurement of the AIR KERMA.
NOTE 2 This definition assumes that the DOSE PROFILE is centred on z = 0.
NOTE 3 A single axial scan is typically a 360° rotation of the X-ray source.
NOTE 4 When the TOMOGRAPHIC SECTIONS overlap, e.g. in CT SCANNERS with a “z-flying FOCAL SPOT”, the
denominator of the integral needs to be replaced by the total nominal width along z of overlapping tomographic
sections. For example, if the percentage of overlap is 50%, then the denominator would be replaced by 0,5 × N × T.
NOTE 5 Typically the z-axis is the axis of rotation.
NOTE 6 The CTDI is designed to include most of the scattered radiation.
100
NOTE 7 See Annex CC for explanation.
201.3.204
CT PITCH FACTOR
Replace, in Note 3, the text “or N × T are” by the word “is”.
---------------------- Page: 7 ----------------------
– 6 – 60601-2-44 Amend.1 © IEC:2012
201.3.212
VOLUME CTDI
w
CTDI
vol
a) for axial scanning
Replace Notes 1 and 2 by the following:
NOTE 1 For the selected CT CONDITIONS OF OPERATION, but irrespective of any scanning length that may be used
clinically, the VOLUME CTDI (CTDI ) is an index of dose based on a convention of 100 mm range of integration
w vol
along the z-axis. For axial scanning, CTDI corresponds to the average dose that would accrue in the PHANTOM
vol
central section of volume equal to the cross sectional area × ∆d.
NOTE 2 For axial scanning with a total table travel much less than N × T, CTDI as defined overestimates the
vol
average dose that would accrue in the PHANTOM central section of volume equal to the cross sectional area ×Δd.
b) for helical scanning
In Note 1 replace the text “or N × T are” by the text “is”.
Replace Notes 2 and 3 by the following:
NOTE 2 For the selected CT CONDITIONS OF OPERATION, but irrespective of any scanning length that may be used
clinically, the VOLUME CTDI (CTDI ) is an index of dose based on a convention of 100 mm range of integration
w vol
along the z-axis. For helical scanning, CTDI corresponds to the average dose that would accrue in the centre of
vol
a 100 mm scan length.
NOTE 3 For helical scanning, when the product of a small number of rotations times the table travel per rotation
is much less than N × T, CTDI as defined overestimates the average dose that would accrue in the centre of a
vol
100-mm scan length.
Add the following new item:
d) for axial scanning without gaps and helical scanning, both involving back-and-forth
PATIENT SUPPORT movement between two positions (shuttle mode)
N ×T
CTDI = n CTDI
vol w
(N ×T ) + R
where
N is the number of TOMOGRAPHIC SECTIONS produced in a single axial scan of the X-ray
source;
T is the NOMINAL TOMOGRAPHIC SECTION THICKNESS;
n is equal to the total number of rotations for the entire scan series;
R is the distance between the two positions;
CTDI is the WEIGHTED CTDI .
W 100
NOTE 1 Seen Figure 201.102.
NOTE 2 CTDI is evaluated as the time weighed CTDI reflecting the varying CT CONDITIONS OF OPERATION.
w w
---------------------- Page: 8 ----------------------
60601-2-44 Amend.1 © IEC:2012 – 7 –
Z
F F
R
I I
N × T
(N × T) + R
IEC 1615/12
F FOCAL SPOT
I ISOCENTRE
Z z-direction
Figure 201.102 – Illustration of N × T,R and (N × T) + R
201.3.214
DOSE-LENGTH PRODUCT
DLP
b) For helical scanning
Replace the existing text:
L is the table travel during the entire LOADING.
by the following new text:
L is the table travel during the entire LOADING, adjusted for dynamic collimation modes if
applicable.
Add the following new note:
NOTE 3 A way for obtaining L could be to use the FWHM along a line perpendicular to the TOMOGRAPHIC PLANE at
isocenter of the free-in-air DOSE PROFILE for the entire scan. In the absence of dynamic collimation this is
approximately equivalent to table travel during the entire LOADING.
Add the following new item:
d) for axial scanning without gaps and helical scanning, both involving back-and-forth
PATIENT SUPPORT movement between two positions (shuttle mode)
DLP = CTDI × ((N ×T) + R)
vol
where
N is the number of TOMOGRAPHIC SECTIONS produced in a single axial scan of the X-ray
source;
T is the NOMINAL TOMOGRAPHIC SECTION THICKNESS;
R is the distance between the two positions.
201.3.215
COMPUTED TOMOGRAPHY DOSE INDEX FREE-IN-AIR
CTDI
FREE AIR
Replace the existing symbol by the following:
CTDI
free air
---------------------- Page: 9 ----------------------
– 8 – 60601-2-44 Amend.1 © IEC:2012
Replace the existing text of the definition by the following:
integral of the DOSE PROFILE representative of a single axial scan along a line through the
ISOCENTRE and perpendicular to the TOMOGRAPHIC PLANE divided by N × T according to the
following
+L/2
D (z)
= dz
CTDIfree air
∫
N × T
−L/2
where
D(z) is the DOSE PROFILE representative of a single axial scan along a line z through
ISOCENTRE and perpendicular to the TOMOGRAPHIC PLANE, where dose is reported as
ABSORBED DOSE in air and is evaluated free-in-air in the absence of a PHANTOM and the
PATIENT SUPPORT;
N is the number of TOMOGRAPHIC SECTIONS produced in a single axial scan of the X-ray
source;
T is the NOMINAL TOMOGRAPHIC SECTION THICKNESS;
L is at least (N × T) +40 mm, but not less than 100 mm.
NOTE 1 This definition assumes that the DOSE PROFILE is centred on z = 0.
NOTE 2 When the TOMOGRAPHIC SECTIONS overlap, e.g. in CT SCANNERS with a “z-flying FOCAL SPOT”, the
denominator of the integral needs to be replaced by the total nominal width along z of overlapping tomographic
sections. For example, if the percentage of overlap is 50 %, then the denominator would be replaced by
0,5 × N × T.
NOTE 3 Typically a RADIATION DETECTOR of length L or longer is used. Annex DD provides an example for
alternate measurements.
Add the following new terms and definitions:
201.3.216
PROTOCOL ELEMENT
set of the particular CT CONDITIONS OF OPERATION necessary to perform a scan
NOTE 1 The following modes are examples of different types of scan: helical, axial, axial series, scanning without
movement of the patient support and shuttle mode.
NOTE 2 To maintain consistency with their respective user interfaces and documentation, various CT SCANNERS
might use terminology different from “PROTOCOL ELEMENT”, e.g., “scan”, “scan group”, “scan series”, etc., which
actually means “PROTOCOL ELEMENT”
NOTE 3 A PROTOCOL ELEMENT is typically associated with a defined clinical task, clinical context, anatomical
region, and/or age or size group. It corresponds to one sequence of scanning in a CT EXAMINATION.
201.3.217
CT EXAMINATION
group of PROTOCOL ELEMENTS used for the entire COMPUTED TOMOGRAPHY PROCEDURE for a
particular PATIENT
201.3.218
DOSE NOTIFICATION VALUE
value of CTDI , CTDI per second, or DLP used to trigger a notification on the control
vol vol
panel
NOTE A DOSE NOTIFICATION VALUE could represent a level of concern associated with a dose index value that
would exceed a value normally expected for the PROTOCOL ELEMENT (e.g. a diagnostic reference level or similar
value determined by the RESPONSIBLE ORGANIZATION).
---------------------- Page: 10 ----------------------
60601-2-44 Amend.1 © IEC:2012 – 9 –
201.3.219
DOSE ALERT VALUE
value of CTDI or DLP used to trigger an alert on the control panel
vol
NOTE A DOSE ALERT VALUE could represent a level of concern (e.g. avoidance of deterministic effects) higher than
that of a DOSE NOTIFICATION VALUE, and it would therefore warrant more stringent review and consideration before
proceeding.”
201.4 General requirements
201.4.3 ESSENTIAL PERFORMANCE
Replace the existing text of this subclause with the following:
Addition:
For CT SCANNERS for which the INTENDED USE includes COMPUTED TOMOGRAPHY as the
principal means of guidance in invasive procedures (e.g., involving the introduction of a
device, such as a needle or a catheter into the body of the PATIENT), any ESSENTIAL
aspects related to such use shall be identified in the ACCOMPANYING DOCUMENTS
PERFORMANCE
and in the RISK MANAGEMENT FILE.
NOTE An example of what would not be considered ESSENTIAL PERFORMANCE is the extraction of needles where
images are not required for guidance.
Compliance is checked by inspection of the ACCOMPANYING DOCUMENTS and the RISK
MANAGEMENT FILE.
201.7.9.101 Reference to ACCOMPANYING DOCUMENTS
Replace the following line:
– LIGHT FIELD 203.115
by the following new line:
– Light marker 203.115 c)
Add the following new lines:
– ESSENTIAL PERFORMANCE 201.4.3
– Alignment of the top of the PATIENT SUPPORT 201.101.2
– Top of the PATIENT SUPPORT 201.101.3
– Table sag (stiffness of the PATIENT SUPPORT) 201.101.4
– Integral light markers for PATIENT marking 201.101.5
– Typical scan mode to provide images for RTP 201.101.6
– HU-value conversion 201.101.7
– Geometric accuracy of image data 201.101.8
– Information in the ACCOMPANYING DOCUMENTS 203.10.2
– Display and recording of CTDI and DLP 203.112
vol
201.8.8.3 Dielectric strength
Replace the existing third paragraph with the following:
---------------------- Page: 11 ----------------------
– 10 – 60601-2-44 Amend.1 © IEC:2012
If the HIGH-VOLTAGE GENERATOR can only be tested with the X-RAY TUBE connected, the test
voltage may be lower but shall not be less than 1,1 times the NOMINAL X-RAY TUBE VOLTAGE of
the HIGH-VOLTAGE GENERATOR or X-RAY TUBE ASSEMBLY ( whichever is lower).
NOTE 101 For the NOMINAL X-RAY TUBE VOLTAGE of the HIGH-VOLTAGE GENERATOR, see also subclause 201.8.4.101,
Limitation of high voltage to the NOMINAL X-RAY TUBE VOLTAGE.
201.9.2.4.101.3 Linear movements of the PATIENT SUPPORT and gantry
In the last sentence of the first paragraph replace "25 mm after actuation" with "50 mm after
actuation".
Add the following two new paragraphs after the existing first paragraph:
If a scan mode is selected in which the PATIENT SUPPORT cannot stop within 25 mm after
actuation of the emergency stop, before the scan is initiated the CT SCANNER shall display an
alert on the CONTROL PANEL regarding this situation and instruct the OPERATOR to ensure the
PATIENT area of travel is free from obstruction.
The ACCOMPANYING DOCUMENTS shall identify the scan modes that cannot meet the 25 mm
emergency stop distance.
Replace the existing compliance statement by:
Compliance is checked by functional test and inspection of the ACCOMPANYING DOCUMENTS.
201.12.1.102 Accuracy of recorded CT EXAMINATION data
Replace existing item a)by the following:
a) When a RADIOGRAM for preview (as described in 203.115 of this particular standard) is
provided, the position of the TOMOGRAPHIC SECTIONS shall be clearly indicated on the
RADIOGRAM.
The indication of the position of the TOMOGRAPHIC SECTIONS shall be accurate within
± 2 mm.
Add the following additional clauses:
201.101 Requirements for CT SCANNERS providing images for RADIOTHERAPY
TREATMENT PLANNING (RTP)
201.101.1 General
Clause 201.101 applies only to CT SCANNERS whose INTENDED USE includes providing image
data for RADIOTHERAPY TREATMENT PLANNING (RTP).
Requirements related to the CT SCANNER (gantry, PATIENT SUPPORT, light markers) and
conversion of Hounsfield Units to electron and mass density are addressed.
201.101.2 Alignment of the top of the PATIENT SUPPORT
201.101.2.1 General
The ACCOMPANYING DOCUMENTS shall describe the procedures for aligning the top of the
PATIENT SUPPORT with respect to the TOMOGRAPHIC PLANE such that the long axis of the top of
the PATIENT SUPPORT is aligned vertically and horizontally over the maximum scan range along
the z direction.
---------------------- Page: 12 ----------------------
60601-2-44 Amend.1 © IEC:2012 – 11 –
Compliance of the alignment requirements in subclauses 201.101.2.2 and 201.101.2.3 is
checked by inspection of the ACCOMPANYING DOCUMENTS.
201.101.2.2 Alignment of the PATIENT SUPPORT in the vertical plane (tilt)
The alignment procedure shall require the accuracy of the alignment to be ±0,5º or less with
respect to the horizontal plane (Figure 201.103).
The alignment procedure shall require this measurement to be taken on the retracted top of
the PATIENT SUPPORT, without load, after installation.
Y
Z′
t
Z
1 2
IEC 1616/12
Z Z-axis
Z’ Axis of the top of the PATIENT SUPPORT
t Tilt angle
1 Gantry
2 PATIENT SUPPORT
Figure 201.103 – Vertical alignment of the PATIENT SUPPORT
201.101.2.3 Alignment of the PATIENT SUPPORT in the horizontal plane
a) The alignment procedure shall require the axis of the horizontal movement of the top of
the PATIENT SUPPORT to be perpendicular to the x-axis of the TOMOGRAPHIC PLANE within
± 1º.
b) The alignment procedure shall require the centerline of the top of the PATIENT SUPPORT to
be marked at the front end (M1) and at a distance of 1 m from the front end (M2). The
difference between the centerline and the z-axis indicated by the sagittal light marker shall
be measured at the position of the scan plane for both M1 and M2. Neither d1 nor d2 shall
exceed 2 mm (see Figure 201.104). If the sagittal light marker does not extend to the scan
plane, the measurement shall be taken at the external light marker position.
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– 12 – 60601-2-44 Amend.1 © IEC:2012
X
M1
d1
Z
Z′
M2
1 IEC 1617/12
Figure 201.104a
---------------------- Page: 14 ----------------------
60601-2-44 Amend.1 © IEC:2012 – 13 –
X
M1
Z
d2
Z′
M2
1
IEC 1618/12
Figure 201.104b
Z Z-axis
Z’ Axis of the top of the PATIENT SUPPORT
1 Gantry
M1, M2 Markings on the top of the PATIENT SUPPORT
d1, d2 distance of Markings from Z-axis
Figure 201.104 – Z-axis alignment of the
PATIENT SUPPORT in the horizontal plane
201.101.3 Top of the PATIENT SUPPORT
The surface of the PATIENT SUPPORT shall be flat or an ACCESSORY to make it flat shall be
specified in the ACCOMPANYING DOCUMENTS and shall be made available.
The PATIENT SUPPORT should allow use of the positioning aids of the therapy system.
201.101.4 Table sag (stiffness of the PATIENT SUPPORT)
Table sag shall be specified for ranges of 40 cm (typical scan length plus shift to reach the
scan plane).
NOTE Corrections for table sag might be needed in the process of RTP.
The sag of the PATIENT SUPPORT in the scan plane shall be evaluated according to the
following test specification:
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– 14 – 60601-2-44 Amend.1 © IEC:2012
– Starting at the gantry-side end of the top of the PATIENT SUPPORT, distribute a load of
135 kg evenly over a length of 1,9 m (or maximum length of the top of the PATIENT
SUPPORT whichever is less);
– position the gantry-side end of the top of the PATIENT SUPPORT in the scan plane
(position 1);
– measure the vertical position of the top of the PATIENT SUPPORT in the scan
...
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