Improving Mobility and Independence for
Elderly, Blind and Visually Impaired People
Julian Hine
Amir Nooralahiyan
Transport Research Institute and Dept. of Electronic and Electrical Engineering
Napier University, Edinburgh, EH10 5BR, U.K.
tel: +44 131 4555141
fax: +44 131 4555138
E-mail: J.Hine@napier.ac.uk
1. Summary
Improvements in confidence and perceived safety have been shown to be major determinants of levels of personal mobility and independence. Enhanced personal mobility and increased personal independence are significant determinants of the quality of life amongst elderly and visually impaired groups while poor mobility is often associated with an inadequate level of control over daily needs. The role of new technology in improving levels of mobility and independence amongst elderly and disabled groups is likely to become increasingly important. This paper outlines the potential impact of a beacon-based neighbourhood auditory location finder system for blind, older and visually impaired people on levels of mobility and independence. The beacon-based system outlined in this paper addresses the need for the elderly in general to feel confident and safe in the built environment.
| Top |
2. Background
The overall aim of this research is to develop and assess the impact of a beacon-based neighbourhood auditory location finder system for elderly, blind and visually impaired people on levels of mobility and independence. Enhanced personal mobility and increased personal independence are significant determinants of the quality of life amongst elderly and visually impaired groups while poor mobility is often associated with an inadequate level of control over daily needs (1,2). The role of new technology in improving levels of mobility and independence amongst elderly and disabled groups is likely to become increasingly important (3). The continued implementation of the Disability Discrimination Act (1995) in the UK, combined with new technology will have important implications for access to goods and services, housing, transport and employment (4). The beacon-based system outlined in this paper addresses the need for the elderly in general to feel confident and safe in the built environment. Research has indicated that the visually impaired have more accidents whilst walking and using public transport than sighted people (5). Improvements in confidence and perceived safety have been shown to be major determinants of levels of personal mobility and independence (6, 7). Independence will be assessed through a number of daily life activities including access to local goods and services. Specifically the aims of this research are to:
(a) design, develop, install and test the beacon based auditory location finder (ALF) with distress call facilities in emergency situations;
(b) monitor subject behaviour through the use of video, and to undertake questionnaire surveys and in-depth interviews with elderly and visually impaired people before and after system implementation;
(c) assess the effectiveness of this system on the quality of life experienced by elderly and visually impaired people from an objective and subjective point of view with respect to parameters such as personal mobility, independence, perceived safety and confidence;
(d) develop links with other institutions, charities, authorities and other parties involved in developing similar systems, to further develop these devices and extend their functionalities.
Much work has been conducted into supplementing auditory information for the visually impaired using ultrasound and more recently global positioning systems (8,9). Many of these devices have not been evaluated comprehensively, using a methodology encompassing video assessments of behaviour, tracking, and attitude and perception studies. This paper outlines a system which will be developed and evaluated encompassing (i) a geographically programmable auditory location finder; and (ii) local emergency calls to in house wardens giving the location of the caller. The system differs significantly from other systems that have been developed. It will incorporate a distress call facility and has the capability of being installed without changing the specification of the beacons if they are moved to different locations. This enables reproduction of the same set of beacons for different areas. The system will also be of a flexible design so that it can be adapted to suit the needs of those with other mobility impairments, which are not necessarily limited to older age groups. Other work has also highlighted the extent to which individuals plan their routes around formal crossing facilities (10). The system outlined in this paper will identify and informs the user of the location of crossing facilities.
| Top |
3. Implementation of proposed system
The beacon-based system in a designated neighbourhood would comprise of the following two specific functionalities: 1) geographically programmable auditory location finder; and 2) distress call facility to local emergency services or in-house wardens giving the location of the nearest beacon.
3.1. Auditory location finder
A geographically programmable device referred to as Auditory Location Finder (ALF) is proposed, capable of receiving signals from a set of beacons in the built environment. The received signal is decoded and the resultant signature is used to voice a set of stored synthesised messages on the device. The auditory output informs the user of his/her whereabouts by naming the area, junctions, streets (including building numbers in street) and pedestrian crossings. In addition, information about the locality of shops, post offices, clinics, public telephone and location of ATMs will be stored on the device as appropriate. It can also be programmed to inform the user about safety aspects of a particular junction or the complex layout of a particular crossing. Figure 1 illustrates how such a system may be installed. The important locations and features in a given area is first identified and fitted with a set of non-sophisticated beacons. Using 8-bit digital modulation, each beacon transmits a low power non-licensed prescribed frequency (for example around 176 MHz). A series of 7 bits gives the possibility of uniquely identifying 128 locally installed beacons with no ambiguity at a single location. The 8th bit would be used for error detection. The signal from the beacons has a short range to increase the accuracy of users' locality relative to the position of beacons. This also reduces the possibility of receiving more than one signal at a particular location (i.e., a dedicated zone for each beacon as shown in Figure 1). Weak signals can be rejected by defining a threshold at a specified value to minimise interference from other sources and to enable easy monitoring and identification of the beacon signal. It is worth noting that the interference constraint for dedicated zones is only limited to roads and not for example buildings. This scenario is shown on the top right hand side of Figure 1 where the overlap of zones for the shop and the crossing do not occur on the road or the pavement, and thus has no effect on the operation of ALF.
The beacons are relatively simple and inexpensive to construct. They are initially to be battery-operated transmitters so that they can easily be installed on lampposts or other suitable street furniture. The final version could be operated by solar cells. The installation of beacons would be in close proximity to locations of interest such as crossings, bus stops, shops, banks and other useful buildings and landmarks in the chosen areas. ALF's on-board receiver decodes and cross-references the incoming beacon signals to extract and automatically relay the stored synthesised messages to the user, via an audio output. Location messages can be repeated by pressing the "Locate" button. If the device is not in any beacon zone a message such as "not in zone" or "no messages" will be voiced. A low battery message will also be programmed.
Figure 1 - Beacon-based auditory location finder in the built environment.
The stored messages on the device can be extended to include information on a number of pre-determined areas in the built environment. These could consist of out-of-town shopping centre, a particular part of city centre or areas where friends and relatives live. Each area has a pre-determined set of messages that can be down-loaded to the device. The device can provide for a number of different areas that can be activated at a touch of a button (four areas are shown in Figure 1). It is worth noting that the specification for RF transmission of beacons in different areas remains the same. One set of beacons with a given operating frequency and digital modulation can be reproduced for all areas. Choosing a different area alters the corresponding stored messages on ALF. One obvious problem is the erroneous result if the user has not chosen the correct area. An audio confirmation of the currently selected area every time the device is switched on, or when a different area is chosen, can overcome this problem.
3.2. Emergency calls to in-house wardens
The provision of an effective and mobile distress call to someone such as in-house wardens would undoubtedly increase the confidence of a blind, elderly or disabled person to venture out more often and as such would significantly improve his/her mobility and quality of life. By activating the emergency call button, a dedicated signal is transmitted by the device and received at the wardens' house or any other specific emergency services. ALF requires a relatively powerful transmission to reach the receiver from anywhere within the entire designated area covered by a set of beacons. The transmitted signal would carry the modulation code of the last received signal from the nearest beacon. This would enable the in-house receiver to decode the signal to establish the location of the caller with accuracy comparable to the distance between beacons. Again, for the reasons explained above, the distress call signal transmission can remain the same for all beacon-operated sites. Indeed, the distress call can function regardless of the number of stored areas on the device (four in this case). The process of transmitting the unique signature of the nearest beacon is a totally automatic and autonomous feature and can be used at any beacon-operated site, even though the associated messages of that particular site may not be stored on the device.
| Top |
4. Evaluation
To assess the full impact of the beacon-based system on mobility and quality of life (both objective and subjective), a battery of evaluation techniques will be used, both before and after the installation of beacons. These techniques will include video data collection (to assess the behaviour of subjects along selected routes), questionnaires and in-depth interviews. Video assessments have been used in pedestrian behaviour research (11), and the combination of in-depth interviews and questionnaires is well grounded and has been used to study young mothers and the domestic workplace (12) and wheelchair disability (13). Research on perceptions of traffic related environmental quality and their impact on pedestrian behaviour suggest that subjective assessments are as important as the objective measurement of pedestrian behaviour (10, 11). This type of approach would be valuable in the evaluation of technology where improved perceptions and confidence levels are an objective. The underlying structure of inter-relationships between the questions will emerge from the analysis. A general questionnaire of this form has already been developed and piloted by the research team across the different pathologies that give rise to visual impairment. This will form the basis of the questionnaire.
In-depth interviews with 10 patients both pre- and post- implementation will be used to explore the potential contribution of ALF in weakening the behavioural constraints and unmet needs in relation to travel and daily activities. This approach has proved to be particularly beneficial in identifying linkages between components of perceptions of safety and independence (13).
The system will be evaluated across two designated case study areas in Edinburgh. The test areas will be chosen with the advice and support of the City of Edinburgh Council. The selected trial routes for the subjects, will also cover existing pedestrian crossing facilities at both locations.
A sample of visually impaired adults will be recruited from both macular and glaucoma clinics held at the Princess Alexandra Eye Pavilion, Royal Infirmary in Edinburgh. For this sample clinical records will be available to obtain information on visual functioning. A sample of age-matched normals will also be asked to participate in the evaluation. This will permit comparisons of confidence levels, performance and behaviour between the visually impaired and non-visually impaired. The research design will incorporate a cross-over design. Each patient will visit each site once, one site with the device and one site without the device. Prior to randomly allocating patients to sites, patients will be blocked by severity of visual loss (moderate or severe), and familiarity with areas (well known and little or not at all known).
| Top |
5. Conclusions
The mobility needs of older and disabled people are an important consideration in the development of transport and social policy. There is now a clear interest and desire to develop multi-disciplinary approaches to extend the quality of life for an ageing population and the needs of people with disabilities. This project will be of direct benefit to both national and local authorities responsible for improving personal mobility and accessibility to goods and services, particularly for mobility impaired groups. The proposed study would have the following benefits. It would firstly demonstrate the potential use of a relatively inexpensive portable device aimed at integrating location finding and local emergency calls; secondly, assess the impact of a new technology on improving confidence and independence, and reducing levels of stress amongst elderly and disabled populations in external environments; and thirdly, analyse the contribution of improved personal mobility and independence, stemming from the introduction of new technology, to extending quality of life amongst elderly and disabled groups.
| Top |
References
(1) Bruce, I., McKennell, A. and Walker, E. (1991), Blind and Partially Sighted Adults in Britain: The RNIB Survey, HMSO, London.
(2) Martin, J., White, A. and Meltzer, H. (1989), Disabled Adults: Services, Transport and Employment, OPCS, London.
(3) AgeNet Seminar (1997), New Technology for Old Age, Proceedings of Foresight Workshop, 17th October, Royal Society for Arts.
(4) Minister for Disabled People (1996), Disability Discrimination Act 1995 Information Pack.
(5) Gallon, C., Fowkes, A., and Edwards, M. (1995), Accidents Involving Visually Impaired People Using Public Transport or Walking, Transport Research Laboratory, Project Report 82, Crowthorne.
(6) Carthy, C., Packham, D., Salter, D. and Silcock, D. (1995), Risk and Safety on the Roads: the Older Pedestrian, AA Foundation for Road Safety Research, Basingstoke.
(7) Clayton, A. (1993) (ed) Older Road Users: the Role of Government and the Professions, AA Foundation for Road Safety Research, Basingstoke.
(8) Dodds, A. (1993), Rehabilitating Blind and Visually Impaired People - A Psychological Approach, Chapman and Hall, London.
(9) RNIB (1997), EC TIDE Project Summaries, available at www.rnib.org.uk/wedo/research/european/tideope.html.
(10) Hine, J.P. (1996), "Pedestrian travel experiences: assessing the impact of traffic on behaviour and perceptions of safety using an in-depth interview technique", Journal of Transport Geography, Volume 4, Number 3, pp179-199.
(11) Chapman, A., Wade, F.M., and Foot, H. (1982) (eds), Pedestrian Accidents, John Wiley, Chichester.
(12) Dyck, I. (1990), "Space, time and renegotiating motherhood: an exploration of the domestic workplace", Environment and Planning D: Society and Space, Volume 8 pp459-483.
(13) Ferguson, D. and Jones, P. (1986), HATS Study on Wheelchair Disability in Adelaide South Australia, Transport Studies Unit, Oxford University, Report Number 342.
| Top | | TIDE 98 Papers |