YY 0068.1-2008Medical Endoscopes—Rigid Endoscope - Part 1: Optical properties and test methods (English PDF)

3.1 Endoscope

The endoscopes refer to the medical devices with the means of observation, which enter into the human body cavities via the natural orifices or the surgical incisions created for medical purposes.

3.2 Rigid endoscope

The rigid endoscopes refer to the endoscopes, of which the parts entering into the human bodies cannot curve along the natural orifices or along the created surgical incisions or along other instrument channels.

3.3 Rigid optical endoscope

Optical endoscope It refers to a rigid endoscope containing an optical transmission and illumination path as well as an optical imaging system. The external illumination light can be brought into the human body cavities via the optical illumination path. The human body cavities can conduct external imaging or direct visual observation via the imaging system.

3.4 Rigid optical observation endoscope

Optical observation endoscope The rigid optical observation endoscopes refer to the optical endoscopes whose imaging systems contain eyepieces. It is likely to conduct direct visual observation via the eyepieces.

3.5 Distal

It refers to the position on the endoscope - whose distance, relative to the user, is farther than that of other reference points.

SEE 3 in Figure 1.

3.6 Working length

It refers to the maximum length of the optical endoscope's part that is inserted into the human body.

4.1 General

The optical endoscopes used for medical purposes shall conform to the following requirements. Other rigid endoscopes can be selected and used according to the applicability.

4.2 Field of view and direction of view

4.2.1 Field angle, 2W

The manufacturer shall express the design value of the field angle of the endoscope in any possible forms. The permissible error of the design value of the field angle shall be ± 15%.

4.3 Image-quality

4.3.1 Angular resolution, ra (d)

4.3.1.1 The manufacturer shall give the nominal value of the angular resolution in the center of the field of view, and the corresponding design working distance d in the accompanying files.

4.3.1.2 The permissible error of the nominal value of the angular resolution in the center of the field of view shall be -10% (excluding upper limit).

4.3.2 Range of the effective depth of field

If the manufacturer claims that the optical endoscope has depth of field, the optical endoscope's range of the effective depth of field shall be given in the accompanying files. Otherwise, the fact that there is no depth of field shall be claimed in the accompanying files.

4.3.3 Field quality

The field of view shall have no effects, such as double image or ghost, flashing, etc. It shall also have no defects, such as visible impurities, bubbles, etc.

4.4 Color resolution and reducibility

The optical observation endoscopes shall have good color resolution and reducibility. When using the spectra of the A and D65 standard illuminants specified in the ISO 10526:1999 CIE S 005, and outputting after transmitting via the illumination light path and imaging system, the optical observation endoscope's output spectrum shall still be able to maintain good color rendering properties. The manufacturer shall give the nominal value of this output spectrum's color rendering index Ra in the accompanying files, and shall also explain its meanings. The optical observation endoscope's measured value of the color rendering index under standard illuminants shall not be less than the nominal value.

4.5 Illumination

4.5.1 Illumination change rate

After the sterilization or disinfection test, the integral light energy transmittance of the optical endoscope's illumination light path shall maintain steady. USE output luminous flux for measurement. The change rate of the luminous flux shall not be greater than 20%.

Note: This Clause does not apply to the disposable optical endoscopes.

4.6 Synthetical relative effect of light energy

The manufacturer shall give the nominal value of the synthetical relative self-effect of light energy at Wp's 90% of the field of view in the accompanying files, and shall also explain its meanings. The measured value of this effect of light energy shall not be less than the nominal value.

4.7 Light energy transfer efficiency - Effective luminosity rate

EXPRESS the light energy transfer efficiency of optical endoscopes as effective luminosity rate. For the optical observation endoscopes, USE the symbol DM to express this effective luminosity rate; DEFINE it as the ratio OF the average luminous exitance in object plane TO the average illuminance in fundus image plane. For the non-visual optical observation endoscopes, DEFINE this effective luminosity rate as the discernible minimum luminosity in object plane (Lmin) of the critical display grayscale in image plane.

5.1 Determination of the field of view and direction of view

SEE Appendix A (normative) of this Part.

5.2 Determination of the image-quality

5.2.1 Determination of the angular resolution

SEE Appendix B (normative) of this Part.

5.2.2 Determination of the effective depth of field

SELECT the worst working distance within the range of the effective depth of field for testing. TEST the angular resolution in the center of the field of view at this working distance according to the method specified in the Appendix B (normative) of this Part.

5.3 Determination of the color resolution and reducibility

SEE Appendix C (normative) of this Part.

5.4 Determination of the illumination property

5.4.1 Equipment

USE the following equipment.

5.4.3 Test for the illumination change rate

ADJUST the light intensity of the test light source to the intermediate value.

USE a light flux meter or other equivalent devices to measure the stable value of the luminous flux output by the test light resource via special optical fiber. DENOTE the stable value as the luminous flux Phi-i.

5.4.4 Illumination effectiveness test

USE the test light source to illuminate an integrating sphere. PASTE the cosine translucent material at the light inlet of the optical endoscope's illumination light path. ENTER the small hole on the integrating sphere. The diameter of this small hole shall not be greater than 10% of the diameter of the integrating sphere.

5.5 Determination of the synthetical relative effect of light energy

SEE Appendix D (normative) of this Part.

5.6.1 Equipment

USE the following equipment.

5.6.2 Environmental conditions

The environmental conditions are as follows. […]

5.6.3 Procedures

5.6.3.1 PLACE the cosine radiation screen perpendicular to the endoscope's axis of view. ADJUST the endoscope via axial movement so that the screen area is greater than the area of the observation field of view.

5.6.3.2 For non-visual optical observation endoscopes.

5.6.4 Calculation

CALCULATE according to the Equation (13).

5.7 Determination of the unit relative distortion

SEE Appendix E (normative) of this Part. […]