1、BSI Standards Publication PD ISO/TR 16840-9:2015 Wheelchair seating Part 9: Clinical interface pressure mapping guidelines for seatingPD ISO/TR 16840-9:2015 PUBLISHED DOCUMENT National foreword This Published Document is the UK implementation of ISO/TR 16840-9:2015. The UK participation in its prepa
2、ration was entrusted to Technical Committee 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 responsible for its correct applica
3、tion. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 87406 2 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 Standards Policy and Strategy
4、Committee on 31 July 2015. Amendments issued since publication Date Text affectedPD ISO/TR 16840-9:2015 ISO 2015 Wheelchair seating Part 9: Clinical interface pressure mapping guidelines for seating Sieges de fauteuils roulants Partie 9: Lignes directrices pour lutilisation dun systme de mappage de
5、pression TECHNICAL REPORT ISO/TR 16840-9 Reference number ISO/TR 16840-9:2015(E) First edition 2015-07-01PD ISO/TR 16840-9:2015ISO/TR 16840-9:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no par
6、t 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 member bo
7、dy in the country of the requester. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgPD ISO/TR 16840-9:2015ISO/TR 16840-9:2015(E)Foreword v Introduction vi 1 Scope . 1 2 Definitions and g lossa
8、ry . 1 2.1 Calibration 1 2.2 Coefficient of Variation (CoV) . 1 2.3 Conformity 1 2.4 Contact area . 2 2.5 Creep 2 2.6 Dispersion Index (DI) 2 2.7 Envelopment . 2 2.8 Fomite . 2 2.9 Hysteresis error . 2 2.10 Immersion . 3 2.11 Pressure, stresses, and forces . 3 2.11.1 Axial strain () 4 2.11.2 Perpend
9、icular force (FP) . 4 2.11.3 Pressure (p) 4 2.11.4 Shear force (FS). 5 2.11.5 Shear stress () 5 2.11.6 Shear strain () 5 2.11.7 Friction force . 5 2.12 Sensor saturation 6 3 Applications . 6 3.1 Cushion comparison . 6 3.2 Wheelchair set-up 6 3.3 Client/caregiver education . 7 3.4 Dynamic activity 7
10、3.5 Relevance to activities of daily living . 7 4 Test protocol in a clinic 7 4.1 Infection control 8 4.1.1 Wash hands. 8 4.1.2 Avoid cross-infection 8 4.1.3 Protect the mat 8 4.2 Setting up . 8 4.2.1 Set up mat 8 4.2.2 Prepare test protocol 8 4.2.3 Prepare client file 8 4.2.4 Be consistent . 9 4.2.
11、5 Check mat orientation . 9 4.2.6 Check mat position. 9 4.2.7 Smooth mat into cushion 9 4.2.8 Acclimatize test cushions . 9 4.3 Transferring the client and getting the client into position . 9 4.3.1 Transfer boards . 9 4.3.2 Remove unnecessary items 9 4.3.3 Post-transfer checks.10 4.3.4 Consistency
12、between tests .10 4.3.5 Settling time 10 4.4 Introducing pressure mapping to the client .10 4.4.1 Position of the screen . .10 4.5 Capturing data 10 4.5.1 Identify position of bony prominences .10 ISO 2015 All rights reserved iii Contents PagePD ISO/TR 16840-9:2015ISO/TR 16840-9:2015(E)4.5.2 Record
13、one or more images .11 4.5.3 Repeat the process 11 4.5.4 Check the images 11 4.5.5 Validate the images .11 5 Documentation 11 5.1 File naming protocol .12 5.2 File location.12 5.3 Make notes immediately 12 5.4 Reporting 12 5.5 Photo documentation .12 5.6 Data back-up 12 6 Interpretation .12 6.1 An u
14、nexpected image .13 6.2 An image that is not ideal .13 6.3 The image shows nothing abnormal .13 6.4 IPM views and metrics 13 6.4.1 Isobar (2-D)/contour view 13 6.4.2 3-D/surface view 14 6.4.3 Centre of pressure (CoP) 15 6.4.4 Gradient 15 6.4.5 Asymmetry .15 6.4.6 Interpolation 16 6.4.7 Smoothing .16
15、 7 Limitations .16 7.1 Prediction of pressure injuries .16 7.2 Microclimate 17 7.3 Clothing 17 7.4 Repeatability and relative values .17 7.5 Influence of posture .17 7.6 Sampling frequency .17 Bibliogr aph y .18 iv ISO 2015 All rights reservedPD ISO/TR 16840-9:2015ISO/TR 16840-9:2015(E) Foreword ISO
16、 (the International 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 com
17、mittee has been established 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 electrot
18、echnical standardization. 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 draf
19、ted 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 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 ri
20、ghts. 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 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 const
21、itute an endorsement. 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 c
22、ommittee responsible 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, p
23、osture and postural 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 mot
24、or vehicles Part 6: Simulated use and determination of the changes in properties of seat cushions Part 9: Clinical interface pressure mapping guidelines for seating Technical Report Part 10: Resistance to ignition of non-integrated seat and back support cushions Requirements and test methods Part 11
25、: 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 ISO 2015 All rights reserved vPD ISO/TR 16840-9:2015ISO/TR 16840-9:2015(E) In
26、troduction The purpose of this Technical Report is to provide information as to where interface pressure mapping (IPM) can fit into a clinical assessment of an individual and their seating system, to highlight what can be achieved, and bring awareness of the limitations. The use of IPM in the clinic
27、 is increasingly used to support clinicians in the evaluation of individual seating systems for individual clients. To get the best value from IPM requires a knowledge of the basic concepts of the interface pressure distribution (see Clause 2), the ability to define and apply a correct protocol for
28、the application of IPM (see Clause 4), the ability to prepare correct documentation of the IPM (see Clause 5), and the skill in interpreting the collected data (see Clause 6). The aim of an IPM test session can be different in a clinical or rehabilitation environment. In some cases, it can be a tool
29、 to compare the behaviour of different pressure care or postural cushions. It can also be used to support the clinician in finding the best match between cushion and client. Various applications looking at the broader picture are covered in Clause 3. Whichever the application, the main objective beh
30、ind using an IPM needs to be clear from the beginning.vi ISO 2015 All rights reservedPD ISO/TR 16840-9:2015Wheelchair seating Part 9: Clinical interface pressure mapping guidelines for seating 1 Scope This Technical Report has been produced to guide users in the performance of the tasks that are dir
31、ectly involved in the clinical use of interface pressure mapping (IPM) or are synergistic with its use in a comprehensive wheelchair seating evaluation. This Technical Report does not cover other aspects of the clinical assessment process (e.g. taking a medical history), nor the prescription or trea
32、tment process which might arise from an assessment. These guidelines are not meant to be a substitute for clinical reasoning and judgement within the context of a complete assessment. This Technical Report refers to the state of the art of IPM experiences in a seating scenario. Most of the principle
33、s covered can be extrapolated to whole body (in bed) or to foot assessments, for example. 2 De finiti ons and g lossary 2.1 Calibration Calibration is a process wherein the sensing mat is subjected to known forces. The sensor responses are monitored and modelled in the software. NOTE A record is kep
34、t of the responses (called a calibration file) and whenever the sensors output a similar response, the result is related to the previously known forces. In most cases, this is done by placing the mat in a purpose-built chamber with an air-filled bladder. The bladder is inflated and the pressure in t
35、he bladder is measured. It is assumed to be evenly pressurized over the mat. Calibration allows for the software to accommodate changes with time (creep) or pressure (hysteresis) exhibited by the sensors. Recalibrate the mat whenever the readings look unreliable, after excessive use, or at the manuf
36、acturers recommended interval. Keep track of the uses of the mat and the date of the last calibration. Old calibration files should be retained (old calibration files can be loaded for comparison to determine change over a period). 2.2 C oefficient of V aria tion (C oV) The CoV is expressed as a per
37、centage: = (1) NOTE This is one of the statistical measures available to assess how evenly the pressure is distributed across a support surface. The lower the CoV, the lower the variability in the data set. 2.3 C onformity The ability of the IPM mat to adapt to irregular shapes without creasing. TEC
38、HNICAL REPORT ISO/TR 16840-9:2015(E) ISO 2015 All rights reserved 1PD ISO/TR 16840-9:2015ISO/TR 16840-9:2015(E) 2.4 Contact area Contact area is the area under load NOTE 1 The contact area is approximated by the total number of sensors under load. NOTE 2 Contact area is representative of the aim to
39、distribute the body weight over as large an area as possible. Given the defining equation of pressure (pressure = force/area) the larger the area, the lower the pressure given a constant load. Reference 8recommended that the minimum threshold to be used should be 5 mmHg to avoid inclusion of fluctua
40、ting non-zero values and minimize the effect of noise. 2.5 Creep There are three different manifestations of creep that are of concern: sensor creep, cushion creep, and tissue creep. Sensor creep, inherent in most IPM sensor technology, is the tendency for the sensors to change their reading (output
41、) over time given a constant load (input). NOTE Most IPM systems, for which this is a factor, have built-in software correction for sensor creep. Creep is normally only corrected for during the time the mat is reading. Stopping and starting the readings may interfere with the creep corrections. 2.6
42、Dispersion Index (DI) The DI is defined as the sum of pressure distributed over the ischial tuberosity (IT) and sacral-coccygeal region divided by the sum of pressure readings of loaded sensors over the entire sensor mat, expressed as a percentage. Dispersion Index = A/( A + B) (2) where A is the pr
43、essures of the IT and sacral-coccygeal area; B is the pressures outside the IT and sacral-coccygeal area. NOTE The DI represents the concentration of pressure in high risk areas versus low risk areas and can be indicative of a support surfaces ability to redistribute pressures. DI is also a metric r
44、eported to have good reliability in Reference. 7In Reference 4it was found that interface pressures were “unacceptable” when 55 % of the pressure was at the IT/sacral regions. DI, as compared with pure contact area, may be a more useful metric when performing relative comparisons between cushions. E
45、ffective pressure distribution can be achieved either via envelopment or off-loading of the high risk sites. If one cushion off-loads and the other envelops, DI may offer a better “apples to apples” method of comparison than contact area alone. 2.7 Envelopment The ability of a support surface to con
46、form so to fit or mould around the irregular shape of the body. 2.8 Fomite An inanimate object or substance (such as clothing, furniture, or soap) that is capable of transmitting infectious organisms from one individual to another. 2.9 Hy st er esis err or Hysteresis error is the difference in two m
47、easurements of the same quantity when the measurement is approached from opposite directions. NOTE 1 Hysteresis generally manifests itself in IPM applications as the difference in a given pressure reading depending on whether that pressure was reached by increasing from a lower pressure or decreasin
48、g from a higher pressure.2 ISO 2015 All rights reservedPD ISO/TR 16840-9:2015ISO/TR 16840-9:2015(E) NOTE 2 Hysteresis is a natural phenomenon which occurs in all types of electrical, magnetic, and mechanical devices. A hysteresis loop is generally used to characterize hysteresis. If a sensor is held
49、 at a constant pressure, there is a corresponding electrical output value for that pressure. It would be expected that if that applied pressure rose or fell, the corresponding electrical output value would rise or fall in synchronicity with the applied pressure. Sensor hysteresis is a dynamic effect where the sensor output “lags” behind the corresponding applied pressure as the applied pressure rises or falls (i.e. for a rising pressure, the displayed pres
