1、BSI Standards Publication Wheelchair seating Part 11: Determination of perspiration dissipation characteristics of seat cushions intended to manage tissue integrity PD ISO/TS 16840-11:2014National foreword This Published Document is the UK implementation of ISO/TS 16840-11:2014. The UK participation
2、 in its preparation was entrusted by Technical Committee CH/173, Assistive products for persons with disability, to Subcommittee CH/173/1, Wheelchairs. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all
3、the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2014. Published by BSI Standards Limited 2014 ISBN 978 0 580 83023 5 ICS 11.180.10 Compliance with a British Standard cannot confer immunity from legal obligations. This Publi
4、shed Document was published under the authority of the Standards Policy and Strategy Committee on 30 June 2014. Amendments/corrigenda issued since publication Date Text affected PUBLISHED DOCUMENT PD ISO/TS 16840-11:2014 ISO 2014 Wheelchair seating Part 11: Determination of perspiration dissipation
5、characteristics of seat cushions intended to manage tissue integrity Siges de fauteuils roulants Partie 11: Dtermination des caractristiques de dissipation de la transpiration des coussins de sige censs grer lintgrit du tissu TECHNICAL SPECIFICATION ISO/TS 16840-11 First edition 2014-02-01 Reference
6、 number ISO/TS 16840-11:2014(E) PD ISO/TS 16840-11:2014 ISO/TS 16840-11:2014(E)ii ISO 2014 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2014 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, elect
7、ronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel.
8、+ 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Switzerland PD ISO/TS 16840-11:2014 ISO/TS 16840-11:2014(E) ISO 2014 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Princ
9、iple 2 5 Test apparatus . 2 5.1 Perspiration rigid cushion loading indenter (PRCLI) 2 5.2 Electrical impedance measurement system 3 5.3 Test environment 3 6 Preparation for testing . 3 7 Test method . 3 8 Test report . 4 PD ISO/TS 16840-11:2014 ISO/TS 16840-11:2014(E) Foreword ISO (the International
10、 Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been est
11、ablished has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardiz
12、ation. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance w
13、ith the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of an
14、y patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constitute an endorsemen
15、t. For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary information The committee responsibl
16、e for this document is ISO/TC 173, Assistive products for persons with disability, Subcommittee SC 1, Wheelchairs. ISO 16840 consists of the following parts, under the general title Wheelchair seating: Part 1: Vocabulary, reference axis convention and measures for body segments, posture and postural
17、 support surfaces Part 2: Determination of physical and mechanical characteristics of devices intended to manage tissue integrity Seat cushions Part 3: Determination of static, impact and repetitive load strengths for postural support devices Part 4: Seating systems for use in motor vehicles Part 6:
18、 Simulated use and determination of the changes in properties Seat cushions Part 10: Resistance to ignition of non-integrated seat and back support cushions Requirements and test methods Part 11: Determination of perspiration dissipation characteristics of seat cushions intended to manage tissue int
19、egrity Technical Specificationiv ISO 2014 All rights reserved PD ISO/TS 16840-11:2014 ISO/TS 16840-11:2014(E) Introduction Dissipating perspiration and moisture on seat cushions is important to prevent pressure ulcers, tissue maceration and for comfortable sitting. This part of ISO 16840 specifies a
20、 test method for the measurement of the perspiration dissipating characteristics of wheelchair cushions under test conditions that simulate body loading on support surfaces with flat and contoured profiles. The test method is intended to be applicable to a wide variety of seat cushions that are used
21、 across the world. This part of ISO 16840 specifies apparatus to measure dissipation characteristics (of perspiration) of seat cushions and the approach to be employed in measuring these characteristics. It is the intention of ISO/TC 173/SC 1 to further evaluate the outcomes of this test method and
22、their clinical implications with the aim of developing an International Standard on this topic. ISO 2014 All rights reserved v PD ISO/TS 16840-11:2014 Wheelchair seating Part 11: Determination of perspiration dissipation characteristics of seat cushions intended to manage tissue integrity 1 Scope Th
23、is part of ISO 16840 specifies a method for determining the dissipation characteristics of simulated perspiration exposure on wheelchair seat cushions. This part of ISO 16840 is applicable to wheelchair seat cushions that include a cushion cover. 2 Normative references The following documents, in wh
24、ole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 16840-2:2007, Wheelchair seating
25、Part 2: Determination of physical and mechanical characteristics of devices intended to manage tissue integrity Seat cushions ISO 554, Standard atmospheres for conditioning and/or testing Specifications 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions
26、 apply. 3.1 ischial tuberosity IT one of two locations on the inferior surface of the RCLI or PRCLI that corresponds in position to the location of a human ischial tuberosity 3.2 rigid cushion loading indenter RCLI cushion loading indenter with a rigid exterior surface contour Note 1 to entry: Examp
27、le details of the RCLI are provided in Annex A of ISO 16840-2:2007. 3.3 electrical impedance complex number ratio of the voltage to the current in an alternating current circuit. Note 1 to entry: Impedance extends the concept of electrical resistance to the alternating current circuit. 3.4 perspirat
28、ion rigid cushion loading indenter PRCLI rigid cushion loading indenter modified to the specifications of 5.1 TECHNICAL SPECIFICATION ISO/TS 16840-11:2014(E) ISO 2014 All rights reserved 1 PD ISO/TS 16840-11:2014 ISO/TS 16840-11:2014(E) 4 Principle Human sensible perspiration in the area between the
29、 cushion and buttocks have four possible states: a) existing between a cushion and the buttock (such as with a sealed vinyl cover); b) dissipated into the cushion cover but not into the cushion; c) dissipated more generally into both the cover and cushion; d) drawn away from the cover (which becomes
30、 dry) and into the cushion. We can evaluate the dissipation behaviour of the cover/cushion system by measuring the changing impedance at a location of interest over time following a discharge of simulated perspiration into the area between the rigid cushion loading indenter and the cushion. The test
31、ing system has four elements: a) an RCLI simulating temperature, weight, and shape of a loading buttock; b) a discharge system that releases a discrete amount of solution that simulates perspiration; c) a measurement system of the changing impedance associated with changing solution concentration ne
32、ar the electrodes (indirectly indicating the absorption of the cover/cushion); d) a test environment of temperature and humidity. 5 Test apparatus The following test apparatus is necessary to complete the test method of this part of ISO 16840. 5.1 Perspiration rigid cushion loading indenter (PRCLI)
33、5.1.1 Shape of PRCLI The PRCLI is formed from 4 mm 1 mm polycarbonate sheet formed according to the specifications for a rigid cushion loading indenter (RCLI) with the inner surface of the shell formed to match the contour specified in ISO 16840-2:2007 Annex A (Figure A.1). 5.1.2 Temperature control
34、 on the PRCLI The PRCLI shall include a means of maintaining the temperature at 27 C 2 C at the inferior surface of PRCLI. 5.1.3 Loading mechanism A means to load the cushion through the PRCLI with a vertical force of 500 N 10 N as in ISO 16840-2. 5.1.4 Discharge mechanism A system to discharge 10 m
35、l 1 ml of 0,01 % sodium chloride (NaCl) solution within 1 s from a hole 0,2 mm in diameter (see Figure 2) located at the ischial tuberosity of the PRCLI (see Figure 1). Figure 1 Drawing of the PRCLI2 ISO 2014 All rights reserved PD ISO/TS 16840-11:2014 ISO/TS 16840-11:2014(E) Dimensions in millimetr
36、es Key 1 round electrode (see 5.1.5) 2 hole for the discharge Figure 2 A-B Cross section 5.1.5 Sensing system (see Figure 2) The sensing system shall have a pair of equally sized round stainless steel electrodes. The electrode shall be a thin plate with diameter of 10 mm 1 mm and thickness of 0,1 mm
37、, preserving smoothness of the buttock surface. The centre of each electrode shall be 15 mm 1 mm from the centre of the hole as shown in the cross sectional diagram of the PRCLI. 5.2 Electrical impedance measurement system An electrical impedance measurement system able to measure electrical impedan
38、ce between the two electrodes, ranging from 0,001 M to 1,0 M, at a sampling rate of 1 Hz. The electrodes shall be connected to the impedance measurement box external to the PRCLI by appropriately shielded electrical wires to minimize electrical noise from the test environment. NOTE Alternating curre
39、nt should be selected as the applying current for measurement to prevent electrolysis of the electrodes when in contact with the solution. 5.3 Test environment A test environment maintained at 23 C 2 C and 50 % 5 % relative humidity as specified in ISO 554 and which includes the means to measure and
40、 record its temperature and humidity during the test period. 6 Preparation for testing Precondition the cushion to be tested by holding it in the test environment of 23 C 2 C, and 50 % 5 % relative humidity for 24 h prior to initiating the test. 7 Test method 7.1 Commence measurement of the impedanc
41、e with a sampling rate of 1 Hz, with the PRCLI not in contact with the cushion/cover surface. ISO 2014 All rights reserved 3 PD ISO/TS 16840-11:2014 ISO/TS 16840-11:2014(E) 7.2 After 1 min 5 s, apply the PRCLI with 500 N load to the cushion and allow 1 min 5 s for settling. 7.3 Between the PRCLI and
42、 the cushion discharge 10 ml 1 ml of the NaCl solution from the tube within 1 s. 7.4 Continue to record the impedance until at least 1 h 1 min has elapsed from the commencement of the test. In some cases, change can be very slow and extended testing will be required. 8 Test report The test report sh
43、all contain the following: a) a reference to this part of ISO 16840 (i.e. ISO/TS 16840-11); b) the name, address, and accreditation status of the testing institution; c) the name and address of the manufacturer of the cushion; d) the date of issue of the test report; e) the test environmental condit
44、ions as specified; f) the model type and nominal size that uniquely describes the test cushion and any cover that is used; g) a photograph of the test cushion with the cover prior to and following the test; h) the preparation of the test cushion; i) a graph of impedance values versus time for the pe
45、riod of the whole test as per 7.4; EXAMPLE See Figure 3 for an example of the type of graph that can result. j) a table of the values of impedance at 1) the commencement of the test, 2) immediately prior to the injection of the NaCl solution, and 3) 12 min 20s intervals (from commencement of test) u
46、ntil the conclusion of the test.4 ISO 2014 All rights reserved PD ISO/TS 16840-11:2014 ISO/TS 16840-11:2014(E) Key (1) start to measure impedance (2) start to load 500N (3) start to pour the liquid a perspiration rigid cushion loading indenter b cushion c discharge mechanism NOTE The dotted graph re
47、presents outstanding moisture dissipation, and the solid line, a cover that does not dissipate the moisture. Figure 3 An example of two possible graphs of the impedance against time when testing according to Clause 7 ISO 2014 All rights reserved 5 PD ISO/TS 16840-11:2014This page deliberately left b
48、lankBSI is the national body responsible for preparing British Standards and other standards-related publications, information and services. BSI is incorporated by Royal Charter. British Standards and other standardization products are published by BSI Standards Limited. British Standards Institutio
49、n (BSI) BSI Group Headquarters 389 Chiswick High Road London W4 4AL UK About us We bring together business, industry, government, consumers, innovators and others to shape their combined experience and expertise into standards -based solutions. The knowledge embodied in our standards has been carefully assembled in a dependable format and refined through our open consultation process. Organizations of all sizes and across all sectors choose standards to help the
