A white cane is conventionally used by visually impaired persons to assist their mobility. To learn its proper operation, training by an orientation & mobility specialist is necessary. However, because the number of specialists is limited, visually impaired persons often do not receive sufficient training. To rectify this issue, a training environment in which the visually impaired can train independently is required. This paper proposes a training system that enables the visually impaired to learn white cane techniques using illusory pulling cues. Specifically, in the white cane touch technique, which is a basic white cane technique, a system that targets the swing width of the white cane is presented by illusory pulling cues. To verify the efficacy of the system, a prototype was implemented and evaluated via user tests. The results confirmed that the error of the swing width of the white cane decreased following use of the proposed system. The proposed system will contribute to the development of the mobility of the visually impaired by enabling them to train with the white cane independently and spontaneously, thereby reducing the workload of specialists.

For visually impaired people, a white cane is an important aid for obtaining information about the surrounding environment. Although the visually impaired should attend this training by orientation & mobility (O&M) specialists to learn proper cane technique, the number of specialists is limited. In our previous study, we developed a training system that enabled the visually impaired to learn white cane techniques using illusory pulling cues. In the previous prototype system, a cane grip-type device was developed with a built-in vibrator to generate asymmetric vibration stimuli, and illusory pulling cues were fed according to the position of the cane tip. Although the prototype system showed positive results, issues related to the lack of user-friendliness of the device associated with the wired drive and the impractical gripping method were observed. This study developed a more practical white-cane-type device for O&M training, envisioning independent training for the visually impaired, which improved the above-mentioned issues. Specifically, the device was wireless and had a vibration mechanism for the gripping method of the general cane technique, and its validity was demonstrated by evaluation experiments. In addition, the paper explains the usefulness of the device as per discussion with active O&M specialists. The results of the evaluation experiments indicated that the devices were implemented to satisfy the requirements for cane training.

Title: Basic Study of the Influence of the Manner of Grasping, Number of Contacts, and Auditory Information on Recognition of Hardness of Objects by Visually Impaired Persons Using White Canes | Keywords: white cane, visual impairment, tactile information, auditory information | Author: Kiyohiko Nunokawa, Manabu Chikai, Kouki Doi, and Shuichi Ino

This study aimed to identify the physical factors contributing to the perception of the hardness of objects tapped using white canes, which are commonly used by the visually impaired for autonomous walking. First, physical factors such as vibration tapping sounds and reaction forces were measured during the indirect tapping of rubber sheets with different hardness using a white cane. Second, we determined the relationship between the subjective hardness perceived by the visually impaired individuals and the physical factors through multivariate analysis. In addition, we estimated the contribution of each factor. The result indicates that the white cane vibrated at similar frequencies during tapping even when the hardness of objects changed. In contrast, the tapping sound varied widely with the variation of the hardness of the rubber sheet. In addition, the peak values of the reaction forces significantly changed depending on the hardness. Based on the results of the multivariate analysis, the contributions of tapping sounds and reaction forces to hardness perception were remarkable. In contrast, the contributions of vibrations could not be found using our analytic method. These findings will help in the design and evaluation of support equipment for the visually impaired.

Braille as a means of communication for children and persons with visual impairment plays an important role in supporting their social independence. However, learning Braille is very difficult, and many persons with adventitious visual impairment who are not conversant with Braille are unable to read Braille. One likely reason behind this is that the common Braille pattern is not necessarily easy for Braille reading beginners such as persons with adventitious visual impairment. Consequently, it is necessary to quantitatively evaluate the readability of Braille patterns for Braille reading beginners and incorporate such findings in Braille design. Moreover, suitable Braille printers are also required to precisely reproduce easily readable Braille patterns. This chapter describes experiments to evaluate the effect of paper-based Braille on Braille pattern readability and introduces a variable size Braille printing system for printing Braille patterns from the experiments to be easily readable by Braille reading beginners unfamiliar with Braille reading.