Sometime in the distant past a blind person took a stick and worked out that it was a pretty good tool for safety and mobility. Thousands of years later, that simple tool is still around and doing a good job. Now in 2009 - is this as good as it gets? Surely there must be a technological wonder on the horizon that will revolutionise safety and way-finding for people with vision impairment. Orientation and Mobility (O&M) instructor and futurist Doug Baldwin expects that even in this post-industrial age, the long cane will not be superseded. He cites the facts that the pen and pencil did not disappear with the advent of the word processor, nor the radio with the emergence of television (Baldwin, 2003).
However, since the formalisation and development of O&M as a profession, there have been many investigations into other adaptive mobility devices. Farmer and Smith (1997) classified these within the plethora of mobility devices available as being either a dog guide, a cane or an Electronic Travel Aid (ETA).
Electronic travel aids have seemed to attract the most interest perhaps due to their sophistication, novelty or the attempt by their inventors to ‘think outside the square’ with respect to safe and independent travel by vision impaired people. Do you remember the Mowat Sensor, Sonic Guide, Laser Cane and Sonic Pathfinder? Do you remember the fervour with which these devices were embraced, the excitement in learning what makes them tick, how to use them and even in letting clients try them? After these devices lost their lustre, only to be replaced by the next ‘craze’, are they still in the archive room collecting dust? Anecdotally it seems as though the most enduring mobility devices commonly used are Adelaide’s own Miniguide and a smattering of Ultracanes (N. Misso, personal communication, October 2, 2009).
While there has been an abundance of mobility devices, there have been fewer specialised orientation devices. Bentzen (1997) has referred to three primary categories of orientation aids, namely models, maps and verbal aids. Use of any orientation aid however presumes that there is an understanding of spatial concepts and cognitive mapping skills. It is important to recognise that mobility for those who are blind is a complex conceptual and biomechanical challenge, so too is the art and science of maintaining orientation.
Our profession has responded to this challenge with the development of tactual maps (which have been used since people could draw in the sand). Entering the twentieth century we ‘raised the stakes’ and delivered the audio map and the talking compass.
In 1985, Loomis and a team of researchers from The University of California, Santa Barbara proposed a Personal Guidance System (PGS) with a potential for Global Position System (GPS) capability. Their proposal reached fruition in 1994 with the development of a prototype that incorporated three key functional elements, specifically; a component to determine position in space, a spatial database of the environment to be travelled, and a user-controlled interface (Loomis, Golledge, Klatzky, Spiegle, & Tietz, 1994).
This area of research has since found a niche market that has been spearheaded by Michael May from the Sendero Group (Kurson, 2007). The commercial opportunities for a portable, personal wayfinding device have been realised with the introduction of a range of GPS products developed by Humanware (Humanware, 2005).
The opportunity for Guide Dogs SA.NT to explore what this technology has to offer occurred in 2006. Staff was made aware of two electronic orientation devices, specifically
The sales pitch went something like this – “How would your organisation like to introduce a tool that would take your clients from a position of orientation dependency to one in which they can predict and control their wayfinding capability? They could travel in rural and urban areas, access commercial and personal points of interest, do virtual trips, have maps all around the world, travel in unmapped areas and keep track of their route in a taxi or public conveyance.” Such features as portability, usability, battery life, mapping content, browsing mode and points of interest were important considerations for our agency in choosing a device.
Ideally our agency would then have nominated a project manager to fully investigate the merits of each product, subject the products to further trial and on the basis of these results select the most appropriate device. However, the luxury of resourcing such a process was not possible, and on the basis of the information available agency staff took the plunge and acquired Humanware’s
The Humanware
First introduced in 2003 and becoming wireless in 2005, the
– ‘Explore’, in which general information is given as the traveller encounters it on route,
– Points of Interest (‘POI’), such as ‘Jim’s house’ and
– ‘Search by Address’, giving directions from one location to another by entering the address using number keypad similar to text messaging on mobile phones.
In 2008, the
– ‘Explore’,
– electronic bread-crumbing capability, in which GPS points are recorded at regular intervals, and
– giving directions from the user’s current location to a pre-recorded landmark or follow a pre-recorded (bread-crumbed) route.
However, there is no capacity to enter an address or search by distance when using the
Early in 2008, Guide Dogs SA.NT was offered the opportunity to host an event in conjunction with Humanware and mapping software producer NAVTEQ. The event ‘TrekAbout Adelaide’ aimed at informing and demonstrating three GPS-based assistive devices: the
TrekAbout Adelaide took place in November 2008, and operated in a treasure hunt style with the participants required to locate six Central Business District (CBD) locations using their GPS device within a two hour time limit. While the event was initially planned as a race, due to the discrepancy in the level of participant experience it was decided that the event be held as a ‘come and try’ challenge. The locations were determined by their proximity to one another, location within the Adelaide CBD and avoidance of a ‘follow the leader’ scenario. Locations also needed to be easily identifiable, safely accessible to pedestrians with vision impairment with a minimum of obstacles related to public works. Participants were also accompanied by an O&M instructor or a sighted supervisor (hereafter referred to as observer) to ensure safe travel. The observer in each team was there only to provide support to the participants with regard to safe mobility and technical support relating as required to the GPS device.
Participant selection for the event was from Guide Dogs SA.NT database, both guide dog and long cane users, who had expressed an interest in GPS devices. Due to available resources, a maximum of six clients were invited to participate in the event. Selection criteria also included the participants’ level of experience with information technology or other ETA, and their degree of O&M skills pertinent to safely negotiating the Adelaide CBD.
On the day of the event, five of the six invited participants took part in TrekAbout Adelaide. Two participants used
Invitations were extended to other clients of Guide Dogs SA.NT who might have been interested in finding out more about GPS orientation aids, media who would be interested in covering the event, staff of Guide Dogs SA.NT, Humanware, NAVTEQ, as well as family and friends of the participants. During the luncheon, prizes were presented and the benefits and challenges experienced with the technology were discussed.
Many of the TrekAbout Adelaide participants experienced difficulties with their GPS connection during the event. This impacted on their ability to find all locations in the designated time. This problem might have been due to poor satellite visibility in a CBD environment, described as ‘canyon effect’ due to interrupted or reflected signals from tall buildings or overhead cover (Stopher, 2004). GPS connection can also be compromised on very overcast days (and true to form it was not only overcast on the day but raining as well). As these satellites are owned and operated for military purposes by the United States Government, there are occasions in which repositioning of the satellites impacts on reception in other parts of the world, therefore diminishing signal reception. Some of the devices were relatively new and it is thought that the GPS units might not have acquired a locational memory, whereby connectivity with satellites is more likely through repetitive usage (R. Mandy, personal communication, January 15, 2008).
Participants using the
The agency has experienced inconsistent satellite reception in city areas and accuracy only within 10 metres, likely due to this canyon effect in built-up locations (Stopher, 2004). However, staff seem to receive excellent connection in suburban and country locations, including more accurate timing of information about landmarks. Feedback from agency clients has indicated a stronger preference for using GPS devices in country areas, where there is better satellite reception, less information given and the possibility of more accurate identification of landmarks. Without modification to their devices, clients in city areas have described poor satellite connection and sometimes too much information given with less accuracy.
It is also interesting to note the different experience of long cane users to clients mobilising with a guide dog. Guide dog clients report using their GPS device at all times when they are not at home, whereas a long cane user has described only turning the device on while he is on the bus and for select routes, in order to maintain concentration on long cane use.
Generally agency staff has received positive feedback from clients who have now purchased and are regularly using a
Both
Like many forms of technology, dependency might develop and this can be the source of frustration when GPS devices are non-operational. Vision impaired travellers must be adequately skilled to problem-solve and continue a route ‘offline’ if the situation warrants (e.g., problems with connection or the battery). While on most days a traveller might rely on GPS technology, initially more thorough orientation and training to specific features of a route must be provided to ensure that the client is capable of safely and independently completing the route without if need be, the technology.
The length of a training program with an ETA is influenced by factors including the complexity of the device, the learning speed and needs of the student as well as staff availability. Farmer and Smith (1997) had stated that the ideal length of training will range from 20 to 120 hours, depending on the device, the student and the travel environments. However, it has been the author’s experience that the GPS device itself might continue orientation training incidentally during travel. For example, clients who always carry their GPS device in ‘explore’ mode are better able to describe the areas in which they travel regularly, having a much greater understanding of street names, layout of suburbs, distance and position of streets and landmarks in relation to each other.
Formal lesson plan documents for teaching
The environment is another important consideration in training a client using a GPS device. When in the city there are many more streets, intersections and points of interest than there are in a suburban or rural area. Feedback staff has received from clients suggests that the devices can take some mental effort out of orientation, with the GPS device giving voice output to the user of their current location, as opposed to finding specific orientating landmarks. On the other hand, some clients find constant information distracting or overwhelming.
As for the future directions of GPS technology, Balachandran, Cecelja, and Ptasinski, (2003) at Brunel University in Great Britain are pursuing a system based on the integration of state-of-the-art current technologies, including high-accuracy GPS positioning, Geographic Information Systems (GIS), electronic compass and wireless digital video transmission (remote vision) facility with an accuracy of 3-4 metres. The device is said to provide automated guidance using the information from daily updated digital map datasets, including information about road works or other exceptional conditions.
Similarly,
At Guide Dogs SA.NT clients will continue to receive training and support to use such GPS technology as the
In hindsight, TrekAbout Adelaide was a successful way to introduce GPS technology to instructors, clients and other interested parties at Guide Dogs SA.NT. These ever-evolving tools still have limitations and are designed to complement, not replace traditional mobility aids. However, the technology offers exciting potential to further enhance independent travel for people with vision impairment.