YY/T 0840-2011 PDF in English
YY/T 0840-2011 (YY/T0840-2011, YYT 0840-2011, YYT0840-2011)
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Medical electrical equipment. Radionuclide calibrators. Particular methods for describing performance
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Standards related to (historical): YY/T 0840-2011
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YY/T 0840-2011: PDF in English (YYT 0840-2011) YY/T 0840-2011
YY
PHARMACEUTICAL INDUSTRY STANDARD
OF THEPEOPLE’S REPUBLIC OF CHINA
ICS 11.040.50
C 43
Medical Electrical Equipment - Radionuclide
Calibrators - Particular Methods for Describing
Performance
(IEC 61303:1994, MOD)
ISSUED ON: DECEMBER 31, 2011
IMPLEMENTED ON: JUNE 01, 2013
Issued by: China Food and Drug Administration
Table of Contents
Foreword ... 3
1 Scope ... 4
2 Normative References ... 4
3 Terms and Definitions ... 4
4 Measurement of Instrument Accuracy ... 6
5 Measurement of System Linearity ... 8
6 Measurement of System Repeatability ... 10
7 Measurement of Air-Density Characteristic ... 11
8 Measurement of Sample Volume Characteristic ... 12
9 Measurement of Background Response ... 13
10 Measurement of Long-Term Repeatability ... 14
11 Measurement of Shielding Performance ... 14
12 Accompanying Document and Performance Statement... 15
Appendix A (Informative) Comparison of Clause No. between this Standard
and IEC 61303:1994 ... 16
Medical Electrical Equipment - Radionuclide
Calibrators - Particular Methods for Describing
Performance
1 Scope
This Standard is applicable to well-type radionuclide calibrators with gas-filled
ionization chambers used in nuclear medicine practice.
The purpose of this Standard is to determine the most important characteristics of the
radionuclide calibrator; and to specify the corresponding test methods; so that
manufacturers may declare the characteristics of their equipment in a standardized
way, and to facilitate the comparison between equipment.
2 Normative References
The following documents are essential to the application of this document. For the
dated documents, only the versions with the dates indicated are applicable to this
document; for the undated documents, only the latest version (including all the
amendments) is applicable to this document.
GB/T 17857-1999 Medical Radiology – Terminology (Equipment for Radiotherapy,
Nuclear Medicine and Radiation Dosimetry)
GB/T 24247-2009 Calibration and Usage of Ionization Chamber Systems for
Assay of Radionuclides (IEC 61145:1992, MOD)
3 Terms and Definitions
For the purpose of this document, the terms and definitions given in GB/T 17857-1999
apply.
3.1 Radioactive standard source
A general term that is used to refer to the following standard sources.
3.2 Certified radioactive standard source
Radioactive sources that are calibrated by the laboratory recognized by the national
radiological standard laboratory and have been qualified by the above-mentioned
3.12 Instrument accuracy
The ratio of the largest possible measured value to the true value.
4 Measurement of Instrument Accuracy
4.1 Overview
The instrument accuracy of the reference device is determined by the primary method.
The instrument accuracy of other devices is determined by secondary methods.
a) Primary test method
For each radionuclide, the reference device is calibrated with a standard source,
and the device has a specified radionuclide factor. If a radioactive standard
source is not available, the manufacturer may also use the calculation method
of the radionuclide factor. The calculated radionuclide factor shall be clearly
given.
b) Secondary test method
The calibration of other devices is performed by the method of comparative
measurement, and the selected radionuclide is compared with the reference
device of the same type and structure measured by the above-mentioned
primary method a). This method implies strict quality control procedures for the
reference device. Alternatively, the subsets of a series of radioactive standard
sources that are not compared with the reference device may also be used.
4.2 Primary test method
4.2.1 Test procedure
For devices with radionuclide factors, this test shall be repeated for each nuclide and
each sample container.
The radionuclide shall be placed in a container (e.g., ampoule, vial, syringe) in a certain
form (e.g., liquid); introduce to the measurement position of the device; and apply to
the appropriate radionuclide factors. For each container type, the volume of the
solution shall be equal to the reference volume of the container. The activity of the
radioactive standard source shall be known accuracy, and its accuracy may be traced
back to national standards. Suitable radionuclide factors shall be used. The activity
determined by the device shall be recorded; and the effects of background, radioactive
decay and radioactive contamination shall be corrected. The measurement shall be
repeated until the average standard deviation Sm of the measured value is less than
2/10 of the uncertainty S0 of the activity of radioactive standard source.
radionuclide between 0.74MBq and 37MBq (0.02mCi and 1mCi) to a straight line and
extrapolate it to the beginning of the measurement. The ratio, ER, between the
expected y-value and the measured y-value shall be calculated for each test point. A
curve graph showing the relationship between ER and the measured y-value shall be
drawn and provided. Where the difference between the observed value and the
expected value extrapolated from the low-value straight line is 1% and 5% of the
observed value, the observed activity value shall be marked and explained.
5.2.2 Sub-packaging source method
5.2.2.1 Test procedure
A series of sources shall be prepared, which are obtained by diluting the same raw
material solution of radionuclides with known activity and half-life. At this time, no decay
correction is required. The maximum activity of the source shall be at least the
maximum used activity specified by the equipment. The reading of the minimum
activity source is less than 10 times the background reading of the device. For each
source with an activity level difference of 10 times, their approximate activity ratio shall
be prepared to be 10:5:2:1. The volume, geometry, and sample container of each
source shall be the same and placed in the same measurement position of the device.
No correction factor is required when the measurement is recorded.
5.2.2.2 Evaluation
The measurement results shall be corrected for background and radioactive impurities,
and the expected activity value shall be calculated from the known activity and dilution
factor of the original solution. For each measurement, the ratio, ER, between the
corrected measured activity and the expected activity shall be calculated. The
observed activity value should be plotted relative to the expected activity value and ER.
From this figure, the different values as in 5.2.1.2 shall be found and expressed.
5.3 Secondary test method
5.3.1 Simplified decay source method
5.3.1.1 Test procedure
Except that only one measurement is required for every 10 times difference in the
activity level, the procedure used in 5.2.1.1 shall be followed.
5.3.1.2 Evaluation
The measurement shall be calibrated by 5.2.1.2. The measurement of 10 times and
100 times of the background level shall be used; so as to determine the extrapolation
to the measurement start time. For each of these two points, at least three readings
shall be averaged. For each decimal place of the activity reading, the ratio, ER, shall
be determined. It shall be compared with the corresponding ratio of the reference
mode. The subset of radionuclides shall include high, medium and low energy sources.
The manufacturer shall select a subset of radionuclides and product samples for test
under the premise of ensuring the volume characteristics of a single device.
8.2 Test methods
The radioactive solution shall be introduced into a sample container with a known
calibration value; and the volume of the solution shall be 1/10 of the maximum volume
that can be contained in the container. The container shall be introduced and measured
at the measuring position of the equipment. After correction for background and decay,
the average standard deviation of these measurements shall be specified after
correction for background and decay. The volume shall also be specified. The non-
radioactive solution volume shall be added to the sample container. The volume shall
be 1/10 of the maximum volume that can be contained in the container. The non-
radioactive solution shall have the same chemical form and density as the radioactive
solution. The measurement shall be performed at the same position as the above. This
process shall be repeated until the maximum range is reached.
8.3 Evaluation
The AV value (measured value at volume V) shall be plotted relative to V on the linear
graph; with AV as the Y-axis and V as the X-axis. From the fitted curve, the value
of the reference volume V0 shall be determined; V0 serves as the volume of the
determined system accuracy (see 4.2). The sample volume characteristics are
obtained by determining the ratio of AV to .
9 Measurement of Background Response
9.1 Overview
For each reference device, a test to determine the inherent background response and
response to a known radiation field shall be performed. As a secondary test process,
these tests shall be performed on periodic selection samples of each product drawn
from a given model. Sample selection shall be done in this way: the manufacturer can
guarantee the inherent background response and the response to the known field of
each other device.
9.2 Inherent background response - test method
The equipment shall be placed where the radiation level is lower than 0.2μSv/h. The
radionuclide factor of 137Cs shall be used. The background correction shall not be set.
A series of measurements shall be taken. The average value shall be recorded. The
average standard deviation of the measurement shall be stated.
9.3 Background response to known radiation field - test method
12 Accompanying Document and Performance
Statement
Each radionuclide calibrator shall carry a document containing the following
information:
a) The type and pressure of the gas filled in the ionization chamber;
b) The size of the ionization chamber well;
c) The size of the source support;
d) Type and thickness of shielding;
e) The maximum deviation of the test parameters between the reference device and
other devices shall be determined and explained;
f) The radionuclide factor and instrument accuracy obtained by the relevant test
method (Clauses 4 or 5) for each radionuclide and each sample container with a
suitable reference volume (with or without shielding is optional);
g) Under the reference volume, corresponding to 99mTc, the maximum activity of the
instrument being calibrated;
h) The system repeatability of the full-scale activity value available in the ionization
chamber;
i) The system linearity reported in unit of activity;
j) Air-density characteristics (only for unsealed ionization chamber);
k) For each sample container type and the sample volume characteristics for each
radionuclide;
l) Inherent background effects (with or without shielding is optional);
m) The background effect determined in 9.3 (with or without shielding is optional);
n) Long-term repeatability and its reference date of the radionuclide factor of the
ionization chamber test source (with or without shielding is optional);
o) The radionuclide content of the ionization chamber test source (including
pollutants and their half-lives);
p) A certificate describing the test results obtained by a specific device.
...... Source: Above contents are excerpted from the PDF -- translated/reviewed by: www.chinesestandard.net / Wayne Zheng et al.
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