1、BSI Standards Publication Wheelchair seating Part 12: Apparatus and method for cushion envelopment testing PD ISO/TS 16840-12:2015National foreword This Published Document is the UK implementation of ISO/TS 16840-12:2015. The UK participation in its preparation was entrusted by Technical Committee C
2、H/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 the necessary provisions of a contract. Users are responsi
3、ble for its correct application. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 90009 9 ICS 11.180.10 Compliance with a British Standard cannot confer immunity from legal obligations. This Published Document was published under the authority of the Sta
4、ndards Policy and Strategy Committee on 31 March 2015. Amendments/corrigenda issued since publication Date Text affected PUBLISHED DOCUMENT PD ISO/TS 16840-12:2015 ISO 2015 Wheelchair seating Part 12: Apparatus and method for cushion envelopment testing Siges de fauteuils roulants Partie 12: Apparei
5、llage et mthode dessai de lenveloppement du coussin TECHNICAL SPECIFICATION ISO/TS 16840-12 Reference number ISO/TS 16840-12:2015(E) First edition 2015-03-01 ISO/TS 16840-12:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015 All rights reserved. Unless otherwise specified,
6、no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic 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 mem
7、ber body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 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 16840-12:2015 ISO/TS 16840-12:2015(E)Foreword iv Introduction v 1 Scope . 1 2 Norma
8、tive references 1 3 T erms and definitions . 1 4 Indenter construction . 2 4.1 Materials . 2 4.2 Tolerances and finishes . 2 4.3 Indenter elements 3 4.3.1 Trochanter bar . 3 4.3.2 Trochanter buttons 3 4.3.3 Bulbous indenter half 4 4.4 Indenter assembly 5 4.5 Sensor locations . 6 4.5.1 General 6 4.5.
9、2 Elevation 16 4.5.3 Elevation 27 4.5.4 Elevation 37 4.5.5 Elevation 47 5 Instrumentation hardware 8 5.1 Electronics 8 5.2 Loading equipment . 8 6 Preparation of test cushion . 8 6.1 Cushion adjustment 8 6.2 Preconditioning the cushion to the test environment 8 7 Envelopment test method . 8 7.1 Rati
10、onale. 8 7.2 Method . 8 7.2.1 Setting the datum height for the indenter . 8 7.2.2 Pre-conditioning the cushion 8 7.2.3 Measuring the seat cushion thickness 9 7.2.4 Load application and data collection . 9 7.3 Calculations .10 8 Test report 11 Annex A (normative) Method adaptions for cushions that ut
11、ilize offloading 13 Bibliography .14 ISO 2015 All rights reserved iii Contents Page PD ISO/TS 16840-12:2015 ISO/TS 16840-12:2015(E) Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing Inte
12、rnational Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison wi
13、th ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directive
14、s, 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 with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some o
15、f 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 any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declaratio
16、ns 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 endorsement. For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about
17、 ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information. The committee responsible for this document is ISO/TC 173, Assistive products for persons with disability, Subcommittee SC 1, Wheelchairs. ISO 16840 consists of
18、the following parts, under the general title Wheelchair seating: Part 1: Vocabulary, reference axis convention and measures for body segments, posture and postural support surfaces Part 2: Determination of physical and mechanical characteristics of devices intended to manage tissue integrity Seat cu
19、shions 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: Simulated use and determination of the changes in properties Seat cushions Part 10: Resistance to ignition of non-integrated seat and ba
20、ck support cushions Requirements and test methods Part 11: Determination of perspiration dissipation characteristics of seat cushions intended to manage tissue integrity Technical Specification Part 12: Apparatus and method for cushion envelopment testing Technical Specification The following parts
21、are under preparation: Part 9: Clinical interface pressure mapping guidelines for seating Technical Report Future parts dealing with methods for determining heat and water vapour characteristics and clinical guideline for the measurement of postural support surfaces and body segments are planned.iv
22、ISO 2015 All rights reserved PD ISO/TS 16840-12:2015 ISO/TS 16840-12:2015(E) Introduction This part of ISO 16840 provides details of test equipment and a method for the measurement of “performance” of a wheelchair cushion intended to use immersion and envelopment to reduce local areas of pressure (b
23、y effectively supporting more tissue). The primary elements that represent the basic cushioning effect of a cushion are immersion and envelopment. Immersion into the cushion (the depth that a body penetrates into the surface) and the envelopment of the body (the intimacy of the cushion to the body)
24、combine to define the potential cushioning performance of the cushion. In this test, the distribution of forces across the surface of the indenter is evaluated with multiple indenter sizes and masses. The accommodation of the cushion to the changes in indenter size and mass are representative of the
25、 changes in size and mass of the occupant that can occur in the life of a wheelchair user or between different users. Issues related to the use of devices that measure the forces between the body and a support surface (i.e. pressure mapping systems) have led to the use of an instrumented indenter, w
26、hich has fewer sensors, but sensors which are high quality and exhibit repeatability, accuracy, and thus reliability. ISO 2015 All rights reserved v PD ISO/TS 16840-12:2015 Wheelchair seating Part 12: Apparatus and method for cushion envelopment testing 1 Scope This part of ISO 16840 specifies appar
27、atus, test methods, and disclosure requirements for characterization of wheelchair seat cushion immersion and envelopment properties using instrumented indenters to characterize the interface pressure of each indenter and the test cushion by measuring the cushioning effects of immersion and envelopm
28、ent. This part of ISO 16840 can be considered to expand the characterization of products intended to manage tissue integrity (ISO 16840-2) and provide a standardized indenter for other wheelchair seating tests. It does not provide information specific to cushion performance for a particular individu
29、al user. This part of ISO 16840 includes a method that is specific to 220 mm and 255 mm indenters. Dimensions and loads are provided for the 380 mm indenter to allow for extension of the methods for bariatric applications. 2 Normative references The following documents, in whole or in part, are norm
30、atively 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/IEC Guide 98-3, Uncertainty of measurement Part 3: Guide
31、to the expression of uncertainty in measurement (GUM:1995) ISO 1302, Geometrical Product Specifications (GPS) Indication of surface texture in technical product documentation 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions apply. 3.1 adjustable cushi
32、on cushion in which adjustments can be made in a reversible fashion Note 1 to entry: See 3.2. 3.2 cushion adjustment modification to the volume, size, hardness, pressure, or other physical characteristics of the cushion surface to accommodate the applied load and the indenter size in accordance with
33、 the manufacturers instructions 3.3 base points lowest two points of indenter when ready for use Note 1 to entry: See Figures 6 and 7. Note 2 to entry: The base points correspond with the ischial tuberosities on the human pelvis. TECHNICAL SPECIFICATION ISO/TS 16840-12:2015(E) ISO 2015 All rights re
34、served 1 PD ISO/TS 16840-12:2015 ISO/TS 16840-12:2015(E) 3.4 elevation sensor locations relative to the base points of indenter when ready for use Note 1 to entry: See Figure 6. Note 2 to entry: Elevation 1 : Sensors at the base points of the indenter (a total of two sensors). Elevation 2 : All sens
35、ors 5 mm superior to the base points (a total of eight sensors). Elevation 3 : All sensors 20 mm superior to the base points (a total of six sensors). Elevation 4 : Sensors 40 mm superior to the base point (a total of two sensors). Note 3 to entry: When in use, the base points of the indenter (Eleva
36、tion 1) aim to represent the lowest points of the ischial tuberosities. 3.5 envelopment ability of a cushion to conform, so as to fit or mould around the irregular shape of the body 3.6 immersion depth to which a body penetrates into a cushion from an uppermost plane 3.7 instrumented indenter anatom
37、ical form that is loaded with a prescribed force and has embedded sensors that return pressure values 3.8 multiplexer electronics board that converts the signal from the sensors into pressure data 3.9 load distribution relative comparison of force or pressure values read by the sensors 3.10 of f lo
38、ad i n g clinical practice of reducing or removing pressure from one area of the body to another in an effort to reduce risk of injury EXAMPLE Reducing the pressure under the ischial tuberosities and increasing pressure on the thighs or other parts of the seated body. 4 Indenter construction 4.1 Mat
39、erials The indenter shall be constructed from hardwood or similar material that is sufficiently rigid to not deform when subjected to the forces required for simulating the application of human body mass to surfaces. The material shall be treated (if necessary) to minimize the effects of moisture, a
40、nd shall not be adversely affected by normal laboratory testing conditions (0 C to 35 C; 25 % to 75 % relative humidity). Surface finish to at least N7 (according to ISO 1302; approximate average surface roughness). 4.2 T oler anc es and finishes Unless otherwise stated, all dimensions in Clause 4 s
41、hall be 0,5 mm and all edges and corners shall be finished with a minimum 5 mm radius. Surface finish to at least N7 (according to ISO 1302; approximate average surface roughness).2 ISO 2015 All rights reserved PD ISO/TS 16840-12:2015 ISO/TS 16840-12:2015(E) 4.3 Indenter elements 4.3.1 Trochanter ba
42、r Use a 375 mm 50 mm 20 mm bar with a series of slots carved in the beam to allow for wire routing. The bulbous indenter halves and trochanter buttons are fixed to the trochanter bar. Refer to Figure 1. Dimensions in millimetres 20 375 375 50 80 155 220 295 R10 typ. THRU ALL 14 25 13 14 362 50 20 Fi
43、gure 1 Trochanter bar construction 4.3.2 Trochanter buttons 51 mm 25 mm 19 mm blocks emulate the trochanters. Each trochanter button shall have a flat section where the sensor is located. Refer to Figure 2. NOTE Trochanter buttons are not required on the 380 mm indenter. ISO 2015 All rights reserved
44、 3 PD ISO/TS 16840-12:2015 ISO/TS 16840-12:2015(E) Dimensions in millimetres 51 19 R22 29 25 29 51 19 6 14 THRU ALL 25 19 Figure 2 Trochanter button construction 4.3.3 Bulbous indenter half This is a disc with a convex curve outwards (see Figure 3). The outwards curve diameter defines the size of th
45、e indenter (e.g. a 220 mm indenter has a 220 mm diameter) as referenced in Table 1. The disc diameter is a function of the outward curve and the height of the curve. Each half has eight sensor locations, as described in 4.5.4 ISO 2015 All rights reserved PD ISO/TS 16840-12:2015 ISO/TS 16840-12:2015(
46、E) Dimensions in millimetres d 55 A A 2*d 19 a 5 20 c b 19 typ. 6 14 typ. 19 a SECTION A-A Figure 3 Bulbous indenter half Table 1 Bulbous Indenter dimensions INDENTER a b c d 220 mm 110 mm 35,0 17, 5 85,0 mm 255 mm 127,5 mm 32,5 16,0 92,5 mm 380 mm 190 mm 26,5 13,0 128,5 mm 4.4 Indenter assembly Ass
47、emble the indenter using appropriate fasteners that will maintain the structural integrity of the indenter in all aspects of testing. Assembly drawings are shown in Figure 3 for the 220 mm and 255 mm indenter and Figure 4 for the 380 mm indenter. ISO 2015 All rights reserved 5 PD ISO/TS 16840-12:201
48、5 ISO/TS 16840-12:2015(E) Dimensions in millimetres Figure 4 Indenter assembly for 220 mm and 255 mm indenters Dimensions in millimetres Figure 5 Indenter assembly for 380 mm indenter 4.5 Sensor locations 4.5.1 General The following is a list of sensor locations and abbreviations. All sensors are sy
49、mmetric about the midline of the instrumented indenter. For left and right sensor location configurations, refer to Figure 6. 4.5.2 Elevation 1 The left and right lowest points along the bulbous surface on the instrumented indenter.6 ISO 2015 All rights reserved PD ISO/TS 16840-12:2015 ISO/TS 16840-12:2015(E) 4.5.3 Elevation 2 The force sensor locations along the bulbous contour of the surface with a vertical height difference of 5 mm from the base
