This document is hosted on the Trace R&D Center Web site. Please visit our home page for the latest information about Designing a More Usable World - for All.
Public information systems and appliances are increasingly being designed to include features to allow them to be used directly by people with disabilities. However, we do not know at present how to design such systems so that they can be accessed by everyone, especially those with severe or multiple disabilities where use of a personal assistive device might be required. One mechanism for allowing these individuals to access public information appliances would be to include a low-cost infrared link as a part of the devices' design. Users could then interface with the device using their own interface - braille display, etc. - on their personal assistive technology. A standard interaction protocol for such an infrared link is under development as a cooperative project with participants in both the U.S. and abroad. The protocol is based upon a small number of robust commands intended to be used in conjunction with the IrDA infrared standard. The protocol is suitable for both public and home systems/ appliances. An initial implementation on a touchscreen kiosk has been carried out. Plans for incorporation in assistive technology devices are underway.
Once limited to ATMs, which allowed individuals access to basic banking services around the clock, the information appliance industry has grown to include everything from touch screen telephones to building and airport information kiosks. Increasingly, individuals with disabilities have access concerns as our society becomes more dependent on the use of these types of electronic appliances. However, if some universal design concepts are applied in the development of these systems, perhaps a greater percentage of the population will want to and also be able to utilize these systems.
For example, an individual who was blind could use a separate device (e.g., personal computer with voice or Braille) to access the information appliance provided they could communicate with it. They would be able to find out what was on screen at any point in time (text and buttons or controls). They could have that information displayed for them on their remote device and activate the controls, also from their remote device.
Another example might be an individual with a physical disability who was unable to reach or use the standard controls (e.g., someone with high spinal cord injury who used sip and puff controlled wheelchair). This individual could view the information on the regular screen of the electronic appliance or their personal assistive device, and use the assistive device to activate the buttons or controls.
The simple addition of an infrared port on the electronic appliance would allow individuals with visual and physical disabilities to both locate and interact with the electronic information appliance. However, without a standard protocol or interaction language, it is unlikely that such infrared ports would be deployed or used.
The Universal Disability IR Communication Link is intended to be used with a number of electronic appliances that have already begun to appear in the market place. These include:
The Universal Disability IR Communication Project has several design objectives and requirements. The objectives are as follows:
To meet these objectives, the Universal Disability IR Communication Link will also require the following:
The link must always be looking for a connection (so that the person with a disability can approach a system and have the system recognize them without requiring the person to activate the link from the system. We may need to utilize other wireless technologies [e.g., RF] to assist individuals using the IR link in navigation to and/or location of "targets"
A first draft or "strawman" protocol for the Universal Disability IR Communication Link is being proposed as follows:
PART I: Protocol for communication from the "aid" to the "information device". There are three commands that can be sent by an assistive device (e.g., aid):
| RESET | #R <ret> | reset system to start (local home) |
| LIST | #L <ret> | send a list of information and action items |
| ACTIVATE | #item reference number <ret> or verbal name of item <ret> to activate this item |
(Note: When the user sends the "list" command, the device may optionally display the names or reference numbers next to the items on the screen to facilitate access by users who can see the screen but who must use an alternate device connected via the IR-link to "push" the buttons etc.)
PART II: Protocol for communication from the "information device" to the "aid". All information sent by the "information device or electronic appliance" is in response to commands from the user (e.g., aid).
In response to RESET: The device sends "reset received" and then "done," along with any text necessary to reflect a change of context to the user (e.g., the when the kiosk is busy or the screen changes to a new screen) when done.
In response to LIST: The device sends a tab delimited table listing all items currently displayed and "accessible" for reading or action. Each information or action item has one line in the table describing it.
In response to ACTIVATE: The device would send "<name of item> received" and then "done" when done. (no return between so they would appear on the same line of the user's display.
Details on the description table sent in response to LIST command:
In order to ensure that the infrared interactions are secure or private, appropriate security measures need to be taken. One approach being explored is based on the PGP two-key system. Basically, it would work like this. Only those portions of the interaction which are confidential would be encoded. Predictable or known sequences of commands would not be encoded. When it came to entering the user's PIN number, for example, the kiosk would generate a PGP code pair and pass the key to the assistive technology. The assistive technology would use that key to pass the user key (which it would generate) back to the kiosk. The user would then transmit their PIN number in encoded fashion to the kiosk. Immediately on receipt of the PIN number, both codes would be discarded and any future communications would occur using a new code key pair.
The current "straw man" protocol presented here is the result of information and input to the project from both industry and consumers via a listserv and through special open working sessions at CSUN, RESNA, and Closing the Gap conferences. An early version of the protocol was also implemented on a touchscreen kiosk prototype. An infrared adaptor was then attached to the serial port of a Braille Lite (a portable, notebook sized assistive device with 18-cell braille display) and used by an individual who is blind to control and use the kiosk using only the braille display on the Braille Lite. Plans are currently underway to have the small routine to support the infrared protocol built directly into a next-generation Braille Lite product.
An evening working session on the IR protocol is planned for the 1996 RESNA conference.
Funding for this work has been provided by the National Institute
of Disability and Rehabilitation Research (NIDRR), U.S. Department
of Education, under Grant #†144-EY31
Mark Novak
Trace R&D Center
2107 Engineering Centers Bldg.
1550 Engineering Dr.
Madison, WI 53706.
This document is hosted on the Trace R&D Center Web site. Please visit our home page for the latest information about Designing a More Usable World - for All.