SEARCH WITHIN CONTENT
Citation Information : International Journal of Orientation & Mobility. Volume 2, Issue 1, Pages 73-80, DOI: https://doi.org/10.21307/ijom-2009-007
License : (CC-BY-NC-ND-4.0)
Published Online: 16-April-2018
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(O&M) instructor and futurist Doug Baldwin expects that even in this post-industrial age, the long cane will not be superseded.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 Trekker from Humanware and PAC Mate from Quantum Technology (now Freedom Scientific). Devices that are now mainstream, for example, GPS systems compatible with mobile phones, were not commonly available at that time. To familiarise staff with The Trekker and PAC Mate equipment, representatives from these respective companies visited Adelaide to demonstrate the products.
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 Trekker in November 2006. The agency then commenced up-skilling its O&M staff. Since that time, Guide Dogs SA.NT has also acquired the Trekker Breeze, which was introduced to Humanware’s range of GPS products in 2008.
The Humanware Trekker and Trekker Breeze are ETAs that use GPS and digital maps to help people with vision impairments find their way in urban and rural areas. Both units inform the user of his or her current location for example, ‘on Gouger Street’, as well as approaching intersections, for example ‘the three-way intersection of Gouger and Market streets on your left’. The ETAs also provide points of interest, for example ‘Adelaide Central Markets nearby’, allowing the person with vision impairment to access in ‘real-time’ interesting locations within the environment other than mobility landmarks.
First introduced in 2003 and becoming wireless in 2005, the Trekker continues to evolve. The latest Trekker system is comprised of a Bluetooth GPS receiver, a stand-alone speaker and a Personal Digital Assistant (PDA) computer equipped with electronic map software. The PDA has been fitted with a specially designed tactile overlay keyboard. The user wears the device over his or her shoulder with a speaker close to an ear to receive synthesised voice output. The Trekker has several functional modes including;
– ‘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 Trekker Breeze was developed in response to user feedback. A much simplified version of the Trekker, the Breeze features single-hand operation with only nine large, distinctive buttons. Many of these buttons directly relate to functions, rather than a menu system, making its use a very intuitive interface. The GPS and speaker are both built-in, and this result in a complete all-in-one unit. Despite being a single device, the Breeze is relatively small, measuring 12.5 x 5 x 2.5 cms and weighs only 200 grams. Similar to the Trekker, the Breeze has several modes of function including;
– 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 Breeze. Routes must be physically negotiated and pre-recorded in advance by the user, instructor or support network.
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 Trekker, Trekker Breeze and BrailleNote GPS. It also enabled Guide Dogs SA.NT to evaluate the effectiveness of this assistive technology as a complement to O&M skills. Clients who were already familiar with GPS had the opportunity to test their O&M skills in a fun and controlled environment and those without previous GPS experience a chance to gain exposure to these devices.
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 Trekker, two used Trekker Breeze and one used Braille Note GPS. Each participant was provided with a name and address of six points of interest and travelled their designated route with their observer. All teams set out together from the Guide Dogs SA.NT office en route to the first location, providing an opportunity to ‘warm-up’. Each team then continued on individualised routes to locate the remaining five locations using their GPS device within a two hour time limit. All teams finished at the same location, the South Australian Museum, where a catered luncheon and presentation took place.
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 Breeze had the advantage of scrolling through their prerecorded route offline when satellite connection was not available enabling them to continue on their respective route. Another client using the Trekker had upgraded components on his unit to include a different GPS receiver (Holux1000), which improved satellite connection significantly.
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 Trekker or Trekker Breeze unit. The benefits clients have described include a greater awareness of streets and landmarks they are passing, giving them a greater understanding of the ‘bigger picture’ town layout. Clients are also using the GPS units for specific situations, for example, to record bus stop landmarks, allowing them to be prompted by the GPS device. Thus reducing dependence on the driver to inform them when they reach their stop. Similarly, a guide dog user has created landmarks for times to cue her dog to find a crossing to the left on a blended kerb.
Both Trekker and Trekker Breeze will provide the most direct route from point A to point B, according to the mapping software primarily designed for motorists. This feature obviously does not take into account ‘local knowledge’ such as quality of footpaths, steep terrain and other potential hazards. Similarly, some city features, for example, city squares or other parklands are not optimally described by the mapping software in terms of pedestrian access. Another consideration for the software engineers is how to cope with the pronunciation of unusual or foreign words. Occasionally the mapping software defaults to, “street with no name” for example, at the entrance to a major car park driveway. For this reason, O&M instructors can rest assured that their role in facilitating independent travel for people with vision impairment is not yet redundant.
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 Trekker and Trekker Breeze have been developed. Special Education Technology British Columbia (SET-BC) and the Provincial Resource Centre for the Visually Impaired (PRCVI) initiated a joint GPS project including lesson plans for introducing the Trekker and Trekker Breeze to O&M students (Rathwell, 2007). Of course, these recommendations for teaching the Breeze must be individualised to meet the needs of clients, their age and degree of familiarity with technology. When considering criteria for using the Trekker or Trekker Breeze, clients must have reasonable tactile sensitivity, the cognitive capacity to process information and access to a computer (R. Mandy, personal communication, January 15, 2009).
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, Drishti is a wireless pedestrian navigation system that integrates several technologies including wearable computers, voice recognition and synthesis, wireless networks, GIS and GPS. The device augments contextual information to the vision impaired person and computes optimised routes based on user preference, temporal constraints (e.g., traffic congestion), and dynamic obstacles (e.g., ongoing ground work, road blockade for special events). This system also provides capability for the user to add intelligence, as perceived by them, to the central server hosting the spatial database (Helal, Moore, & Ramachandran, 2001).
At Guide Dogs SA.NT clients will continue to receive training and support to use such GPS technology as the Trekker and Trekker Breeze. Clients will be given the opportunity to participate in group programs to share experiences and keep up-to-date with the evolving technology. Since these devices are relatively expensive, consideration will be given to developing policies which apply social justice measures to those who require the equipment but are unable to afford it. Staff will also liaise with Humanware, NAVTEQ and other related commercial entities when contemplating similar events.
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.