Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
Attention is drawn to the possibility that some of the elements of this standard may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by the China Food and Drug Administration.
This standard is under the jurisdiction of the Subcommittee on Medical Optics and Optic Instruments of National Technical Committee 103 on Optics & Optic Instruments of Standardization Administration of China (SAC/TC 103/SC 1).
Medical endoscopes - Endoscope supply units - Video camera system
1 Scope
This standard specifies the terms and definitions, requirements and test methods of the video camera system for medical endoscopes.
This standard is applicable to the video camera system for medical endoscopes (hereinafter referred to as “the video camera system”) as endoscope supply units in endoscopic examination and surgery.
This standard is not applicable to the video camera systems with special spectral effects and non-visible spectral imaging.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
GB 9706.19 Medical electrical equipment - Part 2: Particular requirements for the safety of endoscopic equipment
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1 Conversion function
3.1.1
opto-electronic conversion function (OECF)
an ideal relationship between the object space luminance of the video camera system and the corresponding output signal
3.1.2
electro-optical conversion function
the inverse function of OECF
3.2
noise
an internal disturbance arising from the video camera system response to a signal
3.2.1
total noise
the superposition of fixed pattern noise and temporarily varying noise
3.2.2
fixed pattern noise
differences in output signals between area sensor units
3.2.3
temporarily varying noise
differences in output signals between multiple exposures of a unit of an area sensor
3.3
signal-to-noise ratio (SNR)
the ratio of the root mean square value (rms) of the output signal to that of the noise signal at specific signal level, which is expressed as a logarithmic value. It is calculated using Equation (1):
(1)
Where,
S——the output signal;
N——the root mean square value of the noise signal.
3.4
saturation value
a value that the output signal remains constant after the luminance of the object plane is further increased
3.5
static image tolerance
the ratio of the maximum critical object plane luminance to the minimum critical object plane luminance that the video camera system can be distinguished in a single exposure
3.6
spatial frequency response (SFR)
a function between the ratio of the modulation of the output signal calculated by the OECF inverse function to that of the target object plane luminance, and the target spatial frequency
3.7
sine-based spatial frequency response (s-SFR)
SFR when the target is of a sine wave modulated pattern
3.8
modulation
the ratio of the difference between the maximum signal value and the minimum signal value to the sum of the minimum signal value and the maximum signal value plus the minimum signal value
3.9
spectrally neutral
a constant light reflection or transmission characteristic in a certain wave band
4 Requirements
4.1 Requirements for detachable lens
4.1.1 Modulation transfer function (MTF)
The manufacturer shall, in the accompanied document, give the nominal value of the spatial frequency of the detachable lens corresponding to MTF value of 50%, with a tolerance of -20% and with upper limit neglected.
4.1.2 Focal length
The manufacturer shall, in the accompanied document, give the focal length parameters of the detachable lens. For the lens with fixed focal distance, the tolerance for nominal value of the focal length is ±20%. For zoom lens, the tolerance for nominal value of the minimum focal length is +20% with lower limit neglected, and that for nominal value of the maximum focal length is -20% with upper limit neglected.
4.2 Luminance response characteristic
The manufacturer shall, in the technical document, give the electro-optical conversion function or data list of output luminance in relative values of the adaptive monitor. Quantity of sampling points in the data list shall not be less than 10 and they can cover the entire tolerance area.
The luminance calculated from the output signal of the video camera system based on the electro-optical characteristic shall be kept in good linearity with the measured luminance of each gray scale of the test target, and the linear fitting coefficient R2 shall not be less than 0.98.
If the manufacturer claims that the output luminance and object plane luminance of the adaptive monitor are designed based on non-linearity, the manufacturer shall give corresponding evaluation requirements and methods.
Note: OECF inverse function given in the existing standard is recommended for the electro-optical characteristics of the output luminance of the adaptive monitor.
4.3 Signal-to-noise ratio
The manufacturer shall, in the technical document, give the nominal value of the signal-to-noise ratio of the temporarily varying noise of the video camera system and the corresponding camera mode (if multiple camera modes are available for the video camera system).
The tolerance for the signal-to-noise ratio is -20% with upper limit neglected.
4.4 Spatial frequency response
The manufacturer shall, in the accompanied document, give the nominal values of the spatial frequency of the video camera system corresponding to SFR value of 50% and 30% under corresponding measurement conditions. For the video camera system that can be coordinated with various detachable lenses, the model of lens corresponding to the spatial frequency response shall be given. For the video camera system with multiple imaging modes, the video camera mode corresponding to the spatial frequency response shall be given.
The tolerances for the spatial frequency corresponding to a SFR value of 50% and 30% with upper limit neglected shall be given.
4.5 Static image tolerance
The manufacturer shall, in the accompanied document, give the nominal value of the static image tolerance of the video camera system and the corresponding video camera mode (if multiple camera modes are available for the video camera system).
The tolerance for the static image tolerance is -20% with upper limit neglected.
4.6 Electrical safety
It shall be in accordance with GB 9706.19.
Foreword i 1 Scope 2 Normative references 3 Terms and definitions 4 Requirements 5 Test methods Annex A (Normative) Test method for luminance response characteristics Annex B (Normative) Test method for signal-to-noise ratio Annex C (Normative) Test method for spatial frequency response Annex D (Normative) Test method for static image tolerance
Codeofchina.com is in charge of this English translation. In case of any doubt about the English translation, the Chinese original shall be considered authoritative.
This standard is developed in accordance with the rules given in GB/T 1.1-2009.
Attention is drawn to the possibility that some of the elements of this standard may be the subject of patent rights. The issuing body of this document shall not be held responsible for identifying any or all such patent rights.
This standard was proposed by the China Food and Drug Administration.
This standard is under the jurisdiction of the Subcommittee on Medical Optics and Optic Instruments of National Technical Committee 103 on Optics & Optic Instruments of Standardization Administration of China (SAC/TC 103/SC 1).
Medical endoscopes - Endoscope supply units - Video camera system
1 Scope
This standard specifies the terms and definitions, requirements and test methods of the video camera system for medical endoscopes.
This standard is applicable to the video camera system for medical endoscopes (hereinafter referred to as “the video camera system”) as endoscope supply units in endoscopic examination and surgery.
This standard is not applicable to the video camera systems with special spectral effects and non-visible spectral imaging.
2 Normative references
The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the normative document (including any amendments) applies.
GB 9706.19 Medical electrical equipment - Part 2: Particular requirements for the safety of endoscopic equipment
3 Terms and definitions
For the purposes of this standard, the following terms and definitions apply.
3.1 Conversion function
3.1.1
opto-electronic conversion function (OECF)
an ideal relationship between the object space luminance of the video camera system and the corresponding output signal
3.1.2
electro-optical conversion function
the inverse function of OECF
3.2
noise
an internal disturbance arising from the video camera system response to a signal
3.2.1
total noise
the superposition of fixed pattern noise and temporarily varying noise
3.2.2
fixed pattern noise
differences in output signals between area sensor units
3.2.3
temporarily varying noise
differences in output signals between multiple exposures of a unit of an area sensor
3.3
signal-to-noise ratio (SNR)
the ratio of the root mean square value (rms) of the output signal to that of the noise signal at specific signal level, which is expressed as a logarithmic value. It is calculated using Equation (1):
(1)
Where,
S——the output signal;
N——the root mean square value of the noise signal.
3.4
saturation value
a value that the output signal remains constant after the luminance of the object plane is further increased
3.5
static image tolerance
the ratio of the maximum critical object plane luminance to the minimum critical object plane luminance that the video camera system can be distinguished in a single exposure
3.6
spatial frequency response (SFR)
a function between the ratio of the modulation of the output signal calculated by the OECF inverse function to that of the target object plane luminance, and the target spatial frequency
3.7
sine-based spatial frequency response (s-SFR)
SFR when the target is of a sine wave modulated pattern
3.8
modulation
the ratio of the difference between the maximum signal value and the minimum signal value to the sum of the minimum signal value and the maximum signal value plus the minimum signal value
3.9
spectrally neutral
a constant light reflection or transmission characteristic in a certain wave band
4 Requirements
4.1 Requirements for detachable lens
4.1.1 Modulation transfer function (MTF)
The manufacturer shall, in the accompanied document, give the nominal value of the spatial frequency of the detachable lens corresponding to MTF value of 50%, with a tolerance of -20% and with upper limit neglected.
4.1.2 Focal length
The manufacturer shall, in the accompanied document, give the focal length parameters of the detachable lens. For the lens with fixed focal distance, the tolerance for nominal value of the focal length is ±20%. For zoom lens, the tolerance for nominal value of the minimum focal length is +20% with lower limit neglected, and that for nominal value of the maximum focal length is -20% with upper limit neglected.
4.2 Luminance response characteristic
The manufacturer shall, in the technical document, give the electro-optical conversion function or data list of output luminance in relative values of the adaptive monitor. Quantity of sampling points in the data list shall not be less than 10 and they can cover the entire tolerance area.
The luminance calculated from the output signal of the video camera system based on the electro-optical characteristic shall be kept in good linearity with the measured luminance of each gray scale of the test target, and the linear fitting coefficient R2 shall not be less than 0.98.
If the manufacturer claims that the output luminance and object plane luminance of the adaptive monitor are designed based on non-linearity, the manufacturer shall give corresponding evaluation requirements and methods.
Note: OECF inverse function given in the existing standard is recommended for the electro-optical characteristics of the output luminance of the adaptive monitor.
4.3 Signal-to-noise ratio
The manufacturer shall, in the technical document, give the nominal value of the signal-to-noise ratio of the temporarily varying noise of the video camera system and the corresponding camera mode (if multiple camera modes are available for the video camera system).
The tolerance for the signal-to-noise ratio is -20% with upper limit neglected.
4.4 Spatial frequency response
The manufacturer shall, in the accompanied document, give the nominal values of the spatial frequency of the video camera system corresponding to SFR value of 50% and 30% under corresponding measurement conditions. For the video camera system that can be coordinated with various detachable lenses, the model of lens corresponding to the spatial frequency response shall be given. For the video camera system with multiple imaging modes, the video camera mode corresponding to the spatial frequency response shall be given.
The tolerances for the spatial frequency corresponding to a SFR value of 50% and 30% with upper limit neglected shall be given.
4.5 Static image tolerance
The manufacturer shall, in the accompanied document, give the nominal value of the static image tolerance of the video camera system and the corresponding video camera mode (if multiple camera modes are available for the video camera system).
The tolerance for the static image tolerance is -20% with upper limit neglected.
4.6 Electrical safety
It shall be in accordance with GB 9706.19.
Contents of YY/T 1603-2018
Foreword i
1 Scope
2 Normative references
3 Terms and definitions
4 Requirements
5 Test methods
Annex A (Normative) Test method for luminance response characteristics
Annex B (Normative) Test method for signal-to-noise ratio
Annex C (Normative) Test method for spatial frequency response
Annex D (Normative) Test method for static image tolerance
