Use and underuse of mobility aids in individuals with visual impairment: a cross-sectional study of a Norwegian sample

PURPOSE

To examine the use and underuse of mobility aids in individuals with visual impairment.

METHODS

A telephone survey including a probability sample of 736 adults who were members of the Norwegian Association of the Blind and Sighted (response rate: 61%). The interviews took place between January and May 2017, collecting information about access, use, underuse and training in five types of mobility aids (white cane, guide dog, GPS, door-to-door transport and sighted guide). For each mobility aid, we obtained data for underuse defined as non-use despite expecting benefits of use in terms of increased mobility or safety. Participants also answered questions about loneliness (Three-Item Loneliness Scale) and life satisfaction (Cantril's Ladder of Life Satisfaction).

RESULTS

Of the participants, 69% reported using at least one type of mobility aid. Use of specific aids ranged from 12% for the GPS to 52% for door-to-door transport. Estimates of underuse ranged between 14% for door-to-door transport and 28% for GPS. Underuse was not related to lack of resources, as many non-users expecting benefits had access to mobility aids and had undergone training in its use. For example, 81% of non-users of the white cane had access to a cane. In post hoc analyses, non-users who expected benefits from use had lower life satisfaction compared with users.

CONCLUSIONS

Many individuals with visual impairment do not use mobility aids. Strategies that help visually impaired individuals overcome barriers to the use of mobility aids may improve their sense of safety, mobility and quality of life.Implications of rehabilitationThe best mobility aids are those being used. Rehabilitation professionals involved in the provision of mobility aids should be sensitive to the user's lived experiences, and be alert of the cultural meanings of mobility aids and on disability in general.Rehabilitation professionals, social service workers and others need more knowledge of the psychosocial and cultural aspects related to why people do not use their mobility aids.A successful integration of mobility aids in people's daily life cannot be achieved by sufficient accessibility alone. Structured routines for follow-up of those who receive aids should be implemented, so that the aids are actually used.Due to the high rates of underuse and its possible relation to quality of life, promoting regular use of mobility aids should be prioritized.

Tom Pouce III, an Electronic White Cane for Blind People: Ability to Detect Obstacles and Mobility Performances

We present a protocol for evaluating the efficiency of an electronic white cane for improving the mobility of blind people. The electronic cane used during the test is the Tom Pouce III, made of LIDAR sensors (light detection and ranging) with tactile feedback. The protocol comprises two parts. The first part, the “detection test”, evaluates the efficiency of the sensors in the Tom Pouce III for detecting the obstacles found in everyday life (thin and large poles, apertures) under different environmental conditions (darkness, sun light, rain). The second part of the test, the “mobility test”, compares the ability of blind participants to cross a 25 m path by avoiding obstacles with the simple white cane and the electronic cane. The 12 blind participants had between 2 and 20 years of experience of everyday usage of Tom Pouce devices. The results show a significant improvement in the capacity to avoid obstacles with the electronic cane relative to the simple white cane, and there was no speed difference. There was no correlation between the results and the years of experience of the users.

Aesthetics and the perceived stigma of assistive technology for visual impairment

Purpose: The aim of this study was to identify factors that influence the perceived stigma of two assistive devices for visual impairment, namely the white cane and smart glasses.Method: Face-to-face semi-structured interviews with eight European students were conducted to probe their experiences and knowledge related to disability, assistive technology, visual impairment, as well as handheld and wearable devices.Results: Close relationships with disabled people seems to have a positive influence on participants perceptions about stigma, disability, and assistive technology. Academic background seems to not have any influence. The aesthetics of assistive devices was observed as an important factor that influences the adoption or abandonment of the device.Conclusion: Device without negative symbolism but with modern aesthetics (smart glasses) were positively accepted by the participants than the device with traditional aesthetics and symbolisms of visual impairment (white cane). Designers should, therefore, consider aesthetics in addition to functionality in order to avoid the perceived stigma, thereby reducing the chances of device abandonment.IMPLICATIONS FOR REHABILITATIONUnderstanding the factors that influence the perceived stigma associated with assistive technology can help designers and developers to reduce assistive technology abandonment and perceived stigma.Designers need to consider both functionality and aesthetics. While functionality is crucial for the users' adaptation, aesthetics is important for the users' positive perceptions.

Effect of cane length and swing arc width on drop-off and obstacle detection with the long cane

A repeated-measures design with block randomization was used for the study, in which 15 adults with visual impairments attempted to detect the drop-offs and obstacles with the canes of different lengths, swinging the cane in different widths (narrow vs wide). Participants detected the drop-offs significantly more reliably with the standard-length cane (79.5% ± 6.5% of the time) than with the extended-length cane (67.6% ± 9.1%), p <.001. The drop-off detection threshold of the standard-length cane (4.1 ± 1.1 cm) was also significantly smaller than that of the extended-length cane (6.5±1.8cm), p <.001. In addition, participants detected drop-offs at a significantly higher percentage when they swung the cane approximately 3 cm beyond the widest part of the body (78.6% ± 7.6%) than when they swung it substantially wider (30 cm; 68.5% ± 8.3%), p <.001. In contrast, neither cane length (p =.074) nor cane swing arc width (p =.185) had a significant effect on obstacle detection performance. The findings of the study may help orientation and mobility specialists recommend appropriate cane length and cane swing arc width to visually impaired cane users.

Bioinspired electronic white cane implementation based on a LIDAR, a tri-axial accelerometer and a tactile belt

This work proposes the creation of a bioinspired electronic white cane for blind people using the whiskers principle for short-range navigation and exploration. Whiskers are coarse hairs of an animal's face that tells the animal that it has touched something using the nerves of the skin. In this work the raw data acquired from a low-size terrestrial LIDAR and a tri-axial accelerometer is converted into tactile information using several electromagnetic devices configured as a tactile belt. The LIDAR and the accelerometer are attached to the user’s forearm and connected with a wire to the control unit placed on the belt. Early validation experiments carried out in the laboratory are promising in terms of usability and description of the environment.