BS ISO 8600-3:2019 pdf download – Endoscopes — Medical endoscopes and endotherapy devices Part 3: Determination of field of view and direction of view of endoscopes with optics
This document applies to endoscopes designed for use in the practice of medicine. It specifies measurement requirements and describes two test methods for measuring the field of view and direction of view of endoscopes. Method A uses the distance from the distal window to calculate the field of view. Method B uses the distance from the entrance pupil. Other test methods can be used if they obtain equivalent results.
2 Normative references
The following documents are referred to in the text in such a way that some or all of their content constitutes requirements of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 8600‑1, Endoscopes — Medical endoscopes and endotherapy devices — Part 1: General requirements
ISO 8600‑6, Optics and photonics — Medical endoscopes and endotherapy devices — Part 6: Vocabulary
3 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO 8600‑1 and ISO 8600‑6 apply.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
— ISO Online browsing platform: available at http://www.iso.org/obp
— IEC Electropedia: available at http://www.electropedia.org/
Method A applies only if the measuring distance is at least 30 times larger than the distance between the distal end and the entrance pupil  and the accuracy requirement in ISO 8600‑1 is satisfied. Otherwise, the error caused by the distance between the distal end and the entrance pupil in Method A will lead to a systematic measurement error. Method B may be used at any distance. In general, any method is allowed which has the entrance pupil as reference.
Details about test Method A and Method B for measuring endoscope field of view and direction of view, including their shortcomings, accuracies, application prerequisites (e.g. endoscopes with a close focus distance and capsule endoscopes should only use Method B), etc., can be found in the reference  .each of the concentric circles on the target can be coincident with the maximum diagonal field of view. See Figure 1. 5.2.3 Target holder and protractor graduated in degrees. See Figure 1.
5.2.4 Target for field of view and direction of view tests, (see Figure 3) round shape, with two concentric circles of known size (radii of r 1 and r 2 ) and a crosshair at the centre of the circles. It is recommended that r 1 = 18 mm and r 2 = 9 mm, however other sizes are acceptable if the depth of field or field of view does not allow the endoscope to be properly focused on the specified target sizes when used according to the procedure.
5.2.5 Illumination source. white light target-illumination shall be provided with intensity sufficient to visually identify the target structure throughout the endoscope field of view. The illumination can be delivered using either the endoscope illumination or an external source.
6 Test methods
6.1 Method A
a) Mount the target into the target holder. Adjust target in such a way that its perpendicular line through its centre intersects the centre of rotation stage.
b) Mount the endoscope to be tested in the endoscope holder in such a manner that the centre of the distal window is 50 mm ± 0,2 mm from the target centre. Adjust the endoscope in a way that its entrance pupil (if unknown, distal window) is at the centre of the rotation stage.
c) If the depth of field of the endoscope does not include 50 mm, then the endoscope should be mounted at the measuring distance specified by the manufacturer ± 1 % from a target designed to measure the field of view at that measuring distance. Record the measuring distance.
d) Adjust the endoscope holder by looking through the endoscope so that the circles marked on the target and the circumference of the field of view is centred.
e) Determine the largest viewed circle and record it as the field of view, in degrees. For a non-circular image, only segments of the largest circle may be visible.
f) Read and record as the direction of view the angular position, in degrees, of the protractor relative to the long axis of the insertion portion of the endoscope.