Kouki Doi

Development of Communication Assistive Technology for Persons with Deaf-Blindness and Physical Limitation.

The purpose of this study was to develop a system that will provide communication assistance to persons with deaf-blindness and physical limitation, so that they will be able to communicate with others without the help of an interpreter. With this communication system, a person with deaf-blindness and physical limitation uses a control switch to perform input operations based on the duration of the operating time and combination of long and short pulses. When the input is correctly performed, the user receives a feedback from the tablet computer as vibratory stimuli. Similarly, the message that other persons input with a Bluetooth keyboard is transmitted to the user as vibration stimuli. Following the development, we conducted a one-year assessment of the developed communication system in an actual environment with the cooperation of one person with deaf-blindness and physical limitation. . We confirmed that our developed system was useful for such a person, and understood that we must improve upon several aspects. We shall pursue further study, and will aim at providing a better communication environment for persons with deaf-blindness and physical limitation in future.

Vibration of the White Cane Causing a Hardness Sense of an Object

Previously, we conducted a psychological experiment to measure sensitivity to hardness using a white cane. The Results showed that participants had higher sensitivity to hardness when using the white cane compared to when actually tapping the target with their fingertip. This suggests that the white cane acts to provide enhanced feedback on hardness. In this study, we investigated the relationship between vibration and sense of hardness using white canes. We measured frequency of vibration of the ferrule of the cane by acceleration sensor when the cane contacted with target. And using psychological experiments, we then had participants estimate their sense of hardness for each hardness degree. It was found that there is a correlation between the hardness sense and frequency of vibration.

Relationship between Surface Property and Operability of Tablet Terminal with Touch-Sensitive Screen

Intuitively operated touch-sensitive screens are becoming more prevalent in our daily lives. Particularly, the rapidly growing demand for tablets, which are beginning to be used in the educational and medical environments, is said to be leading the market. However, it has been pointed out that it is hard to slide a finger easily on the tablet screen when operating the device, making it difficult to use the device. The present study investigates the relationship between the surface property of a tablet touch-sensitive screen and the easiness of sliding a finger on the screen, and evaluates the influence of the surface property on the operability based on the experimental results.

The Influence of the Manner of Grasping a White Cane on the Ability of Visually Impaired People to Perceive the Texture of Objects

This study examined the relationship between a surface’s texture (i.e., the particle size) and the perception of its roughness obtained from a white cane. The perception of roughness was measured by a magnitude estimation method with nine visually impaired people who used white canes. Their audiovisual information was restricted with eye masks and earmuffs. The perceived texture was investigated with three different styles of grasping the white cane: the index finger grasp, pencil grasp, and thumb grasp. Participants estimated the roughness of 18 waterproof abrasive papers with different particle sizes (6.7 to 279 μm). Because the exponent for this relationship was almost 0.35 for all three grasping styles when the particle size was small, it can be concluded that a small increase in the particle size causes a significant increase in the perceived roughness.

Influence of the Manner of Grasping a White Cane on the Ability of Visually Impaired Persons to Use These Canes for Estimating Object Weights

We have conducted research to obtain fundamental knowledge of the exploration methods used to perceive the characteristics of an object through contact with a white cane. The research has enabled us to examine methods that enhance the accuracy of perceiving objects and the materials and design of a white cane. In this study, we examine whether or not the method of grasping a white cane affects weight perception, with 5 visually impaired people who use white canes in their daily lives as participants. The participants provide estimates for the magnitudes of six weights ranging from 500 g to 1,000 g in steps of 100 g. Results indicate that weight can be determined using a white cane, even though this method is slightly inferior to directly pushing the weight by hand. The weight perception obtained by employing a white cane is not affected by the manner of grasping the cane.

Evaluation of touch-sensitive screen tablet terminal button size and spacing accounting for effect of fingertip contact angle.

Touch-sensitive screen terminals enabling intuitive operation are used as input interfaces in a wide range of fields. Tablet terminals are one of the most common devices with a touch-sensitive screen. They have a feature of good portability, enabling use under various conditions. On the other hand, they require a GUI designed to prevent decrease of usability under various conditions. For example, the angle of fingertip contact with the display changes according to finger posture during operation and how the case is held. When a human fingertip makes contact with an object, the contact area between the fingertip and contact object increases or decreases as the contact angle changes. A touch-sensitive screen detects positions using the change in capacitance of the area touched by the fingertip; hence, differences in contact area between the touch-sensitive screen and fingertip resulting from different forefinger angles during operation could possibly affect operability. However, this effect has never been studied. We therefore conducted an experiment to investigate the relationship between size/spacing and operability, while taking the effect of fingertip contact angle into account. As a result, we have been able to specify the button size and spacing conditions that enable accurate and fast operation regardless of the forefinger contact angle.

Relationship between Weight of Our Developed White Cane and Muscle Load on the Upper Limbs during Swinging Action of the Cane

The present study aimed to investigate the influence of the weight of white canes on upper limb load. Concretely, we conducted quantitative evaluations of the load on upper limb muscles during swinging action of the cane. The white canes used were a new type of white cane newly fabricated using aramid fibers, as well as a conventional type of white cane fabricated using carbon fibers. The results indicated that the newly developed cane reduced the load on the muscles by about 50% in comparison with the conventional type of cane. It became clear that it was possible to sustain the same posture even when used continuously over a long period of time.

Development of a handwritten note-taking system for the support of hard-of-hearing students participating in lectures

Objective Note-taking can be used during lectures to make reasonable accommodation for hard-of-hearing students. Focusing on handwritten note-taking, we have developed a new system aimed at providing better support in terms of reasonable accommodation. Main Content In Japanese higher education, there is an increasing awareness of the importance of reasonable accommodation for students with disabilities. Hard-of-hearing students are provided with note-taking support that helps ensure understanding by providing them with note-takers who write down the lecture content. Usually, two notetakers are assigned to sit together with a hard-of-hearing student. This three-person group typically sits in the first row of the classroom, away from the rest of the class. The eyes of the assisted student are often focused on their notes and tend to miss the subtle facial expressions of the teacher as well as any visual aids that may be projected on the classroom screen. These classroom conditions may decrease the sense of involvement or participation in the class for hard-of-hearing students. To address these issues, the author developed a handwritten note-taking system. Results and Conclusion The results from experimental use of the device in a classroom environment suggests that it can help hard-of-hearing students regain a sense of involvement or participation in their class, because they are able to sit away from their note-takers and find seats of their own and can choose to sit closer to their classmates.

Influences of tactile-dot height and tip radius of curvature on the operational performance of cellular phones

Tactile dots located on operation keys of consumer products such as cellular phones contribute to improving accessibility for older people and people with visual impairment. The Japanese Standards Association (2000) and the International Organization for Standardization (2011) standardized tactile dots. However, reliable data on the appropriate sizes and the shapes was not necessarily available. The purpose of this study is to evaluate influences of the height (0.1, 0.3, 0.55, and 0.75 mm) and the tip radius of curvature (0.1, 0.3, 0.5, 0.7, and 0.9 mm) of tactile dots on the operational performance of cellular phones in younger and older people. Sighted younger and older participants, whose hand was covered by a curtain, operated cellular phones with a tactile dot on its key 5 and without a tactile dot. As the result, both participants performed better at a particular height with larger tip radius of curvature. Furthermore, older participants operated better at high dots like 0.55-0.75 mm. In contrast, younger participants performed better at 0.3 mm and relatively poorly at 0.1 mm and 0.75 mm. Thus, comparatively high tactile dots are useful for improving the accessibility of products for the older and there is an appropriate height range for the younger.

Influences of the edge radius of curvature of tactile dots and bars on their discriminability

Tactile dots and bars serve as tactile landmarks so that people with visual impairment can use same consumer products as those used by sighted people. However, reliable age-related data on the appropriate sizes and the shapes was not necessarily available. The purpose of this study is to evaluate influences of edge radius of curvature of tactile dots and bars on their discriminability in younger and older people to determine the appropriate size of tactile bars (as distinguished from tactile dots). Sighted younger and older participants tactually discriminated the tactile dots and bars presented individually, in random order, by a two-alternative forced-choice task. The results showed that both participants discriminated tactile bars from tactile dots faster and more accurately as the dimensional difference between bar length and width increased, regardless of conditions of edge radius of curvature. Therefore, longer dimensional difference between width and length of tactile bars is an important factor to discriminate tactile bars correctly. On the other hand, tactile dots with a larger edge radius of curvature have higher discriminability than tactile dots with a smaller edge radius of curvature in the case of dots of identical height.