ISO 18562-3:2017 ヘルスケアアプリケーションにおける呼吸ガス経路の生体適合性評価 — Part 3: 揮発性有機化合物（VOC）の排出量のテスト | ページ 10

A.2 Rationale for particular clauses and subclauses

Clause 5 — Voc emissions

Volatile organic compounds should not outgas in excessive amounts from the gas pathways into the flow of gases intended to be delivered to the patient. The amount delivered to the patient should not create an unacceptable risk.

Vocs in the body are characterized by rapid uptake and equally rapid elimination. When the compound is absorbed into the blood stream, it is rapidly distributed throughout the body. The elimination half-lives for vocs from the blood are typically a few minutes to a few hours.

The most relevant parameter is the actual dose-to-patient — the concentration multiplied by the volume the patient inhales or ingests.

5.3 — Test method

d)

The sources of the test daily flow volumes in this document are described in ISO 18562-1:2017, 6.3 and the accompanying rationale for the subclause. The first usage is expected to yield the maximum extraction of vocs and therefore conveys the maximum dose of each substance to the patient.

e)

Common sampling durations range from 30 min to 180 min. The sampling duration chosen needs to allow averaging (e.g. of heater wire control algorithms) and smoothing of any transients in the measurement. The sampling duration might need to be longer to result in a large enough sample volume to allow quantification down to the required detection limit or reduced to prevent overloading of the sampling system. Additional sampling points are then advisable.

Annex B

Reference to the essential principles

This document has been prepared to support the essential principles of safety and performance of gas pathways as components of medical devices according to ISO 16142-1 ^[2]. This document is intended to be acceptable for conformity assessment purposes.

Compliance with this document provides one means of demonstrating conformance with the specific essential principles of ISO 16142-1. Other means are possible. Table B.1 maps the clauses and subclauses of this document with the essential principles of ISO 16142-1.

Annex C

Terminology — Alphabetized index of defined terms

Bibliography