john Gill technology header image

Requirements for the Interconnection of Assistive Technology Devices and Information and Communication Technology Systems

Dr. John Gill
July 2001


Contents

1 Introduction

2 Scenarios

3 The Interface

4 The Questionnaire

5 Recommendations

Appendix 1 Websites

Appendix 2 Relevant Assistive Devices in ISO 9999

Appendix 3 The Wireless Interconnection Technologies

Appendix 4 The Questionnaire

Appendix 5 Responses to the Questionnaire

Appendix 6 Alternate User Interface Standard


1 Introduction

The general approach has been to encourage designers to incorporate features in the standard product which will help people with disabilities. If this is insufficient, then to incorporate a standard method of connecting the user's own device which has an appropriate user interface. But if neither of these approaches provides a satisfactory solution, then use special equipment.

This report looks at some of the aspects of interconnecting assistive devices to information and communication technology (ICT) systems. In particular it is concerned with how assistive technology manufacturers perceive the situation and what needs to be done to reach a consensus.

The assistive devices industry is characterised by a large number of small companies marketing a limited range of devices which may be for a specific disability or for a specific application area. Many of these companies also provide training in the use of their products. Although prices tend to be high, compared with mainstream products, profit margins are modest. Therefore few companies can devote significant resources to research and development.

The technology employed in assistive devices has often lagged behind mainstream products. This is partly because the shelf-life of an assistive device is considerably longer then mainstream products such as mobile phones.

For many years hardwire systems have been used to interconnect devices, but now wireless systems are generating interest and providing the possibility for new services. Infra-red has been in use for some time, but new radio-based systems, such as Bluetooth, could substantially change the market.


2 Scenarios

Up to a few years ago, the usual interface between an assistive device and an ICT system was hard wire, frequently using RS232 or more recently USB. However wireless systems offer the potential for new types of services; some possible examples are given here.

2.1 Public Access Terminals
There are an increasing number of self-service terminals such as cash dispensers (ATMs) and ticket selling machines for public transport. These terminals give a number of problems for disabled users which could be alleviated using wireless technologies:

(a) A wheelchair user may not be able to reach the buttons on the terminal. A hand-held terminal (such as a PDA or a mobile phone) could be connected to the terminal via a wireless system.

(b) A blind person may have difficulty in locating the terminal; a wireless signal to the terminal could trigger an audible location signal from the terminal.

(c) A blind person might want speech output of the information on the terminal's screen; this could be transmitted via Bluetooth to a mobile phone handset.

2.2 Domestic Equipment
The user interfaces on many domestic devices (from washing machines to mobile phones) are difficult to use by people with visual, hearing, physical or cognitive impairments. So the ability to have an alternative user interface could make all the difference to their ability to use the equipment.

2.3 Navigation and Orientation Systems
Visually impaired people often have difficulty in determining whether it is safe to cross the road at traffic lights or the destination of a bus. If the traffic lights and buses had wireless transmitters, the blind person could receive an audible message in a hand-held device such as a mobile phone handset. Such a system could be extended to giving road names at road junctions. It could also be used in indoor environments such as shopping centres or railway stations.

2.4 Hearing Aids
Hearing aid users have particular problems in noisy environments, and a radio-based system would permit the connection of public address systems to their hearing aids; this would be useful in public places such as railway stations, theatres and at sports events.

2.5 Audio Description
Visually impaired people often have difficulties in following the plot on television or in the cinema. One solution is to insert an audio description in the gaps in the dialogue. However such a commentary can be annoying to other people, so it is desirable that only the visually impaired person hears the audio description. One possibility would be to use a wireless system such as Bluetooth to transmit to a headset worn by the visually impaired person.

2.6 Mobile Telephones with Remote Control Facility
Mobile telephones can already include short messaging, location functions, text telephone facilities and speech control. The next generation mobiles will include Internet compatability and picture transmission modes. Combined with Bluetooth the same mobile could be used for remote control of public terminals and domestic appliances. The devices to control and their protocols would be automatically identified thanks to Bluetooth and services built on top of Bluetooth. When the distress button is pressed, the mobile could send an alarm via the mobile net or via the local home bus. In both cases the location information is available, and communication with the service centre is opened automatically.

2.7 Convergence and Diversity
Although the mobile telephone could be used as a remote control or the other way round, it does not mean that we will not find them as separate devices. The remote control at home could be bigger, have bigger buttons and a better display and still offer the same facilities as the mobile telephone with its wireless interface module.


3 The Interface

The above scenarios give some indication of the extensive range of possibilities for interconnecting assistive devices (AD) to ICT systems. In some cases, the assistive device may be a mainstream device normally used for another purpose (eg a mobile phone handset).

In some instances the requirement is to produce output from the ICT system in a different modality (eg convert text on a screen to speech output) or in an enhanced version of the same modality (eg larger characters on a high contrast display). In other cases the requirement may be for transmission of signals which are not usually under user control (eg requesting more time for crossing at pedestrian controlled traffic lights).

Assistive device/service

From ICT system to the AD

To the ICT system from the AD

Status

Text

Graphics

Audio

Video

Control

Text

Graphics

Audio

Video

Braille display

X

X

               

Tactual graphics display

X

X

X

             

Synthetic speech display

X

X

               

Enhanced visual display

X

X

X

             

Keyboard / pointer

         

X

X

X

   

Speech recognition

         

X

X

     

Hearing aid

     

X

           

Tactile hearing aid

     

X

           

Alarm/monitor system

     

X

X

X

       

Smart housing

X

X

X

X

X

X

X

X

X

X

Navigation system

X

X

X

X

X

X

X

     

Table 1 Examples of the type of information to be transmitted to and from the assistive device (NB some systems may use fewer modes than the possible ones indicated).

The present technologies for the interconnection of systems are described in Appendix 3. Over the next few years more technologies will be developed and many of them will have higher bandwidths (eg for transmitting video). However crucial aspects include whether:

  • The standard is uniquely defined
  • The interface is in widespread use for the relevant ICT systems
  • The interface is relatively inexpensive in relation to the cost of the ICT system
  • The interface system is reliable in all relevant environments

In the past only a few standards have met these criteria; examples of hardwire interfaces include RS232 and USB. However the area of wireless systems has been more problematic, but that could change in the next few years. As often is the case, the dominant interface may not be the technically best one but the one supported by the main commercial players.

The level of specification of the interface varies from system to system. Most have standards for audio and text, but none specify all the status and control signals needed in the previous scenarios.


4 The Questionnaire

A questionnaire (see Appendix 4) was sent by Email: to people concerned with assistive technology. Their responses are listed in Appendix 5.

The main points were:

  • Standards are useful but they must allow for future developments.

  • A standard is of limited use if it is not widely implemented.

  • Many disabled users of assistive technology have limited technical skills, so the setup and operation need to be simple and consistent.

  • The interface should not increase significantly the cost of the assistive device.

  • Any standard should build on the work already done eg by the Trace Center (see Appendix 6).


5 Recommendations

1. There needs to be further investigation of the need and appropriate type of standards in this area.

2. It would be unwise for European standards organisations to work in this area without liaising with the relevant organisations outside Europe.

3. There is some urgency in these matters if disabled people are not to lose out from the possible benefits of new wireless systems.


Acknowledgements

The author is grateful for the help of Jose Antonio Collado, and all those who responded to the questionnaire.

Appendix 1

 



John Gill Technology Limited Footer
John Gill Technology Limited Footer