YY/T 1587-2018Medical endoscopes—Video endoscopes (English PDF)

3.1 Conversion function

The conversion relationship between different variables.

3.2 Noise

The disturbance as generated inside the response signal of the video endoscope.

3.3 Signal-to-noise ratio

At a particular signal level, the ratio of the output signal to the root mean square value (rms) of the noise signal, which is represented by a logarithmic value. The representation is as shown in formula (1).

3.4 Saturation value

The output signal value which further increases the brightness of the object while the output signal remains constant.

3.5 Static image tolerance

The ratio of the maximum brightness of the critical object plane to the minimum brightness of the critical object plane that the video endoscope can distinguish in a single exposure.

3.6 Spatial frequency response; SFR

In a video endoscope, the function relationship between the ratio of the modulation of the output signal which is subjected to the calculated value of the reverse function of OECF to the modulation of the brightness of the object plane of the target, and the spatial frequency of the target.

4.1 Materials used in contact with the patient

4.1.1 Metal surface material

If the material used in contact with the patient is a metallic material, the exposed w or wp

4.1.3 Biocompatibility

Materials in contact with patients shall be evaluated for biosafety according to the principles and requirements of GB/T 16886.1, to demonstrate good biocompatibility.

4.2 Field angle

It shall meet the requirements of the field angle in 4.2.1 of YY 0068.1-2008.

4.3 Reflective self-effect of illumination light luminosity

The manufacturer shall give the nominal value of the reflective self-effect of illumination light luminosity ILeR at the 90% field angle of the wp as given in the accompanied documentation. The measured value of the reflective self-effect of illumination light luminosity shall be not less than the nominal value.

The manufacturer shall, in the technical data, give the nominal value of the signal-to-noise ratio of the temporally varying noise of the video endoscope, as well as the corresponding camera mode (if the video endoscope has multiple camera modes).

4.8 Mechanical properties

The mechanical properties of rigid video endoscopes shall comply with the requirements of YY 0068.2.

4.9 Electrical safety

It shall meet the requirements of GB 9706.19.

5.1 Test of material requirements

5.1.1 Surface material

Visual inspection. For products with a surface coating, follow the appropriate test methods as provided by the manufacturer.

5.1.3 Biocompatibility

All tests are preferred to use the relevant standards as described in GB/T 16886.1 and are carried out according to their methods.

5.2 Test of field angle

It shall be carried out according to the method of measuring the field angle as specified in 5.1 of YY 0068.1-2008.

5.3 Test of relative self-effect of illumination light luminosity

The video endoscope is connected to a light source as provided by the manufacturer.

5.5 Test method of signal-to-noise ratio

Check the technical data as provided by the manufacturer.

Use the method as specified in Appendix B to measure the signal-to-noise ratio of the video endoscope.

5.6 Test method of spatial frequency response

Check the contents of the accompanied data as provided by the manufacturer.

Use the method as specified in Appendix C to measure the spatial frequency response of the video endoscope.

5.7 Test method of static image tolerance

Check the contents of the accompanied data as provided by the manufacturer.

Use the method as specified in Appendix D to measure the static image tolerance of the video endoscope.