Baxter, Monk, Doughty, Dewsbury, - Standards and the Dependability of Electronic Assistive Technology

paper outlining the various standards that need to be recognised and considered when considering EAT and telecare for older people.
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  1 Standards and the Dependability of Electronic Assistive Technology Title: Standards and the dependability of electronic assistive technologyAuthors: Gordon Baxter, Andrew Monk, Kevin Doughty, Mark Blythe and Guy DewsburyAffiliation/address:Gordon Baxter, Andrew Monk, Kevin Doughty, Mark BlytheCUHTecDepartment of PsychologyUniversity of York HeslingtonYork YO10 5DDGuy DewsburyDepartment of Computer ScienceUniversity of Lancaster Lancaste r LA1 4YR  Phone: +44 (0)1904 433170Fax: +44 (0)1904 Submission type: Formal paper Filename: BaxterMonkDoughty.docVersion of Word used: vX.    Chapter 1Standards and the Dependability of Electronic AssistiveTechnology G.D. Baxter, A.F. Monk, K. Doughty, M. Blythe and G. Dewsbury 1.1 Electronic assistive technologies as critical systems Electronic Assistive Technology (AT) includes both technology to help people with their daily activities, suchas a door entry, and sensors that can raise alarms on detecting a fall or some other incident in the home i.e. hometelehealthcare (usually abbreviated to Telecare). Electronic AT is of great economic and social value as it allows people to remain in normal homes when otherwise they would be forced to move to some sort of institutionalsetting.Electronic ATs are critical systems in the sense that if they fail there may be resulting injury or distress. Adoor entry system that locks an older person into their home, or opens the door at random times when interferingradio signals are received will cause considerable distress. A social alarm system that leads someone who hashad a fall to believe help is on the way, when it is not, is a danger to life. Given the critical nature of thesesystems one would expect them to be covered by extensive legislation to enforce high standards of design andmanufacture. This paper examines the measures that can be taken in this respect. It can be viewed as preparatoryto a survey of current practice which has yet to be carried out and as the beginning of a campaign to encouragemore visible evaluation of the dependability of electronic ATs. 1.2 Legislation, standards, codes of conduct and guidelines It is well established practice in engineering to record guidelines and standard procedures to ensure good design practice and in most companies these are formalised as part of the quality assurance process for a product.Where this is true staff are expected to be able to demonstrate that they comply with these procedures. Acompany that invests significantly in developing the required knowledge and procedures to ensure dependabilityof their products will want to demonstrate this to their customers. It is thus in their interest to join with other companies and professional bodies to develop public standards that they can sign up to. Eventually, thesestandards may become legal requirements upon all manufacturers. EC directives, for example, are implementedas national legislation by individual member countries of the EC. Manufacturers can show compliance with thelegislation (where required) by conforming to the appropriate standards which have been developed as a way of  promoting perceived wisdom and best practice. Compliant equipment carries a CE marking.The process of developing and publishing a standard is the business of a standards agency. There arespecialist standards organisations, which are national or international such as the British Standards Institute(BSI), and the International Standards Organisation (ISO). Within individual industries, professionalorganisations also develop their own standards, such as the Institution of Electrical Engineers (IEE) in the UK and the Institute of Electrical and Electronic Engineers in the USA. Trade organisations also exist, such as theAssociation of Social Alarm Providers (ASAP), who have developed their own code of conduct for theoperation of a call centre, with which all of its members should comply. However, these codes of practice tendto be very much less formal in their definition and in measures of compliance. Also, membership of professionaland trade organisations is generally not mandatory.    Some standards have been very influential. The ISO 9000 series, for example, are very widely used todemonstrate a systematic quality assurance process. The US military standards (DEF STAN) set the goldstandard for risk analysisIn this paper we will examine two approaches to providing standards in the area of electronic AT. One is todevelop an overarching standard specifically for this purpose and the next section examines medical deviceslegislation as a way of doing this. The alternative is to use a variety of standards as they apply to differentcomponents of the system. This is examined in section 1.4. 1.3 Medical Devices Legislation and Electronic AT The Medical Devices Agency (MDA) in the UK was recently made part of the Medicines and HealthcareProducts Regulatory Agency. The MDA is largely responsible for implementing the three medical devicesdirectives (The Active Implantable Devices Directive (90/385/EEC), The Medical Devices Directive(93/42/EEC), and The In Vitro Diagnostic Medical Devices Directive (98/79/EC)) under the auspices of theSecretary of State for Health. These were recently implemented in the UK by the Medical Devices Regulations2002 (SI 2002 No. 618). One of the latest updates (EN60601-1-2:2002) provides an international standard for EMC testing of Medical Electrical Equipment. This is important both because medical devices need to operatecorrectly in hospital environments that can be quite hostile in terms of interference from other equipment, and because they need to provide very limited electronic ‘noise’ so that other sensitive equipment may not bedisturbed.If a manufacturer  , makes a medical device and intends  placing (it) on the market  , then the Medical DevicesRegulations apply. Each of the italicised terms are defined by the regulations. Manufacturers are defined in a fairly broad sense. The term includes people who build systems fromexisting components, with the intention of placing the resultant system on the market. There is one keyexception, which is the person who assembles or adapts devices already on the market to their intended purpose for an individual person.A Medical Device is defined as “an instrument, apparatus, appliance, material or other article, whether used alone or in combination, including software necessary for its proper application , which — a. is intended by the manufacturer to be used for human beings for the purpose of:i diagnosis, prevention, monitoring, treatment or alleviation of disease,ii diagnosis, monitoring, treatment, alleviation of or compensation for an injury or handicap,iii investigation, replacement or modification of the anatomy or of a physiological process, or  iv control of conception;   and does not achieve its principal intended action in or on the human body by pharmacological,immunological or metabolic means, even if it is assisted in its function by such means. ” This is a very broad based definition. In its literature the MDA provides an incomplete list of examples of medical devices that includes walking aids, prescribable footwear and equipment for disabled people . Thelatter term would seem to embody what many people would describe as assistive technology.Medical devices are divided into three classes by the Directive. These classes directly relate to the level of risk associated with the device, so Class I devices are those generally regarded as low risk, and Class III devicesare those generally regarded as high risk; medium risk devices are divided into two subclasses of Class II.Classification of the devices is determined using a set of rules that form part of the regulations, and there is a feefor obtaining compliance which is about £3,000 for a Class I device. Of course, this fee is but a small part of thecost of employing an engineer to perform a risk analysis, document the risk management applied and submit theapplication for compliance. There are interesting differences between Europe and the USA where the Food andDrug Administration (FDA) enforces the equivalent legislation, however, in both cases obtaining compliancewith this standard is expensive and can be a problem for small start-ups with a single product or large companieswith families of devices to register (Mackenzie, 2002). For these reasons companies will look for exceptionsthat allow them to bypass this legislation. There are also some problems with the associated standard, ISO14971 – Application of risk management to medical devices. These include a lack of definition of risk management as part of the system quality assurance process, and uncertainties in the ways that risk scoring is performed (MacKenzie, 2002).As noted above a person who assembles or adapts devices already on the market to their intended purposefor an individual person is exempt. This excludes individual installations that may differ from home to home.Devices that are developed within one organisation for use within that same organisation are considered to beexempt, because they are not placed on the market. This means, for example, that systems developed by themedical physics department in an NHS trust hospital for use on patients elsewhere in the hospital are exempt. Inaddition, to the explicit exemptions, there are grey areas in the regulations. If a person buys a device of their     own volition as an aid to daily living, for example, then it is not normally considered as a medical device.Similarly, there are some devices that can be considered as having a medical role when they are used bydisabled people, but can also be used by able bodied people. Such devices are not considered as medicaldevices. A door entry system, for example, which allows the person in the home to see who is at the door, andremotely open it is obviously very useful for someone with mobility problems. Such systems are also sold to people without mobility problems, so it would not normally be considered as a medical device. More generally,one can claim that if the technology is sometimes used by people without disease , injury or handicap thenit is not primarily for diagnosis, prevention, monitoring, treatment or alleviation of those afflictions and so theregulations do not apply.Given the major grey areas and exceptions that are embodied within the legislation, the meaning of a CEmarking on electronic AT is not at all clear. If the relevant legislation and standards are not easily defined whatdoes it mean to say that the device meets all relevant European legislation. It is thus very difficult for thestandards to do their job and demonstrate to customers that a product meets high standards of dependability. 1.4 Alternative Standards for electronic AT In trying to identify the current standards that apply to electronic AT, the MDA was contacted directly. Theyindicated that they do not keep a list of the relevant standards. A similar response was also received from theHealth and Safety Executive: they do not have any ongoing work relating to the use of electronic AT in thehome. There are, however a number of standards that could be applied to different system components.Figure 1 is a block diagram representation of a typical telecare system. The sensors and the client are shownin a box that represents the home. In addition to the client, the system will normally have at least one other typeof user: the person who monitors the client’s status through a computer system in a call centre, and may interactwith the carer network (social worker, informal carer, GP and so on). Figure 1.1. Typical telecare system, see text for explanation.Based on Figure 1, there are three obvious areas where standards exist that could be useful in assessing howgood an electronic AT system is: computer systems (the base station in the home and the computer system in thecall centre); people (operator, professional carers and emergency services), and infrastructure. There is a plethora of standards available that apply to systems development. The situation has been described as “TheFrameworks Quagmire” (Sheard, 1997), since there are at least seven identifiable frameworks, each of whichhas several associated standards. Fortunately, there does seem to be a gradual evolution towards newframeworks which encompass the best bits from the old frameworks. Sheard’s assessment of the situation onlyaddresses systems development in the most general sense. In other words, Sheard does not consider the particular standards associated with the development of safety critical systems.
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