Identification of the hardness of an object in a human hand is different according to the hardness of the object. For example, chiropractors identify stiffness in the muscle by using their thumb, which can press more forcefully than the forefinger. However, it has not been shown experimentally if the characteristics of hardness discriminability are different according to fingers. In this study, to clarify the relation between different fingers pressing elastic objects and the characteristics of hardness discriminability, we investigated the differential threshold of hardness using the forefinger and thumb. Additionally, the influence of press force and press displacement on the characteristics of hardness discriminability was clarified. We used 7 elastic test pieces with different Young's moduli as the presented stimuli. We also used the test pieces with hardness sensation judged as 'hard' in our previous research. We conducted the experiment using the constant stimuli method to calculate differential threshold of hardness as one evaluation index of hardness discriminability when using the forefinger and thumb. The results of this experiment showed that the hardness discriminability of the thumb was better than that of the forefinger. In addition, these results suggested that press displacement but not press force should be used to estimate the hardness discriminability and that the thumb is better than the forefinger to discriminate the displacement. These findings clarify the mechanism underlying hardness discriminability in the human hand.

The satisfactory vibrating conditions and the perceptual properties of inducing illusory horizontal shoulder flexion were investigated in this study. The experimental factors were the vibration frequencies of 30, 50, 70, 90, 110, and 130 Hz. We subjectively assessed the presence or absence of an illusion and its vividness on a 5-point scale. Simultaneously, the perceptual time it took for an illusion to appear and the maximum illusory angle was measured. It was found that the maximum occurrence rate of the illusion was 98% at a vibration frequency of 70, 90, 110 Hz. The illusory angle was approximately 30°. It took 7s for an illusion to appear. Based on this knowledge, we plan to develop an interface device that will provide kinesthetic sensations only without the actual motion in a future study. This device could potentially be used for tactile feedback technology in the virtual reality space.

The satisfactory vibrating conditions and the perceptual properties of inducing illusory horizontal shoulder flexion were investigated in this study. The experimental factors were the vibration frequencies of 30, 50, 70, 90, 110, and 130 Hz. We subjectively assessed the presence or absence of an illusion and its vividness on a 5-point scale. Simultaneously, the perceptual time it took for an illusion to appear and the maximum illusory angle was measured. It was found that the maximum occurrence rate of the illusion was 98% at a vibration frequency of 70, 90, 110 Hz. The illusory angle was approximately 30°. It took 7s for an illusion to appear. Based on this knowledge, we plan to develop an interface device that will provide kinesthetic sensations only without the actual motion in a future study. This device could potentially be used for tactile feedback technology in the virtual reality space.

This paper presents a novel sports training system. We developed a visual real-time feedback system that directly transmits a bird's eye view from a drone camera to a player's eyes. Individual physical ability, experience and intuition is important; however, in team sports such as baseball, football and volleyball, players need to perform spatial cognition such that they immediately understand where they, their teammates and their opponents are on the field as if they could see it from a bird's eye view. The objective is to validate the feasibility of the bird's eye view feedback system. In an experiment, nine participants moved and stood between two experimenters as a cut-off man with or without the system. Using the system produced significantly less error than with no system (p < 0.05). In conclusion, this bird's eye view feedback system can improve human spatial cognition.

Braille is a well-known communication tool for the visually impaired. In recent years, as a result of advances in Braille printing technology, the use of transparent resinous ultraviolet cured type (TRUCT) Braille has spread rapidly. As one of the most popular Braille printing technologies, the screen printing method is applied for printing TRUCT Braille. However, the screen printing method produces TRUCT Braille prints of poor quality. In this study, in order to improve the printing quality, we created a device for printing TRUCT Braille. Additionally, we evaluated TRUCT Braille readability for Braille beginner readers by focusing on horizontal and vertical Braille dot distances using our created device. From this study, we found that it was easy to print TRUCT Braille using our device. Braille beginner readers found it easy to read TRUCT Braille with adequate horizontal and vertical Braille dot distances. These findings support the use of TRUCT Braille for new Braille beginner textbooks, as well as for printing Braille signs in public facilities.

The portability of touch-sensitive screen tablets provides high usability under various circumstances, and such tablets are increasingly utilized in the education and other fields. Meanwhile, the design of the graphical user interface (GUI) of such tablets requires careful consideration in order not to lose tablet operability in such diverse situations. In this study, we conduct an experiment to investigate the effect that touch-sensitive screen button size and spacing have on operability, while considering the influence of the angle that the forefinger makes when touching the screen. As a result, we could determine the conditions required for the size and spacing of buttons to allow fast and accurate operation independent of contact angle. Furthermore, we could reveal the relationship between contact angle and area, and investigate the impact of the contact angle when touching smaller buttons.

Braille is a well-known communication tool for the visually impaired. In recent years, as a result of advances in Braille printing technology, the use of transparent resinous ultraviolet cured type (TRUCT) Braille has spread rapidly. As one of the most popular Braille printing technologies, the screen printing method is applied for printing TRUCT Braille. However, the screen printing method produces TRUCT Braille prints of poor quality. In this study, in order to improve the printing quality, we created a device for printing TRUCT Braille. Additionally, we evaluated TRUCT Braille readability for Braille beginner readers by focusing on horizontal and vertical Braille dot distances using our created device. From this study, we found that it was easy to print TRUCT Braille using our device. Braille beginner readers found it easy to read TRUCT Braille with adequate horizontal and vertical Braille dot distances. These findings support the use of TRUCT Braille for new Braille beginner textbooks, as well as for printing Braille signs in public facilities.

The portability of touch-sensitive screen tablets provides high usability under various circumstances, and such tablets are increasingly utilized in the education and other fields. Meanwhile, the design of the graphical user interface (GUI) of such tablets requires careful consideration in order not to lose tablet operability in such diverse situations. In this study, we conduct an experiment to investigate the effect that touch-sensitive screen button size and spacing have on operability, while considering the influence of the angle that the forefinger makes when touching the screen. As a result, we could determine the conditions required for the size and spacing of buttons to allow fast and accurate operation independent of contact angle. Furthermore, we could reveal the relationship between contact angle and area, and investigate the impact of the contact angle when touching smaller buttons.

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.

<p>点字の触読経験の有無によらず利用できる浮き出し文字が, アクセシブルデザインの理念に基づいてエレベータやテレビのリモコンのボタンに採用されつつある. しかし, 浮き出し文字の触知覚特性に関する知見は十分ではない. そこで本研究では, アラビア数字の浮き出し文字のサイズが識別容易性に及ぼす影響を明らかにすることを目的として, 浮き出し文字の識別実験を行った. その結果, 浮き出し文字のサイズとその識別容易性の関係が明らかになった. 本研究によって得られた浮き出し文字の触知覚特性に関するデータは, 国内外の標準規格の制定及び改訂の際に有用な知見となる.</p>

<p>本研究では, タッチパネル携帯端末の操作性向上を目指し, その操作方法がポインティング特性に及ぼす影響を評価することを目的として実験を行った. さらに, 得られたポインティング特性の結果に基づき, タッチ感知領域の設計手法について実験的検討を行った. その結果, ディスプレイ上での操作位置や操作方法がポインティング位置の分布傾向や操作性に影響を与えることが明らかとなった. また, 本実験により得られたポインティング位置の分布傾向に基づき, 楕円によるタッチ感知領域の検討とその評価を行った. その結果, 片手操作でみられる特定の方向にポインティング位置の分布が偏るような特徴をもつターゲットに対して, 正方形による設計手法よりも効率的にタッチ感知領域を設計できる可能性が示唆された.</p>

<p>視覚障害者に対する触覚サインとして, 消費生活製品の操作終了部に付す凸バー (凸状の横バー) と操作開始部に付す凸点 (凸状の丸い点) が国内外で規格化されているが, 今後, 規格の改正や新たな関連規格の制定にあたり, これらの推奨寸法に関する豊富な基礎データが必要である. 特に, 触知覚特性に重要な影響を及ぼす利用者の年齢や触知による情報入手経験の観点から, 視覚障障害者が凸バーと凸点を指先で識別できる寸法の条件が網羅的に明らかではない. そこで本研究では, 日常生活を触知に依存していない若年及び高齢の晴眼者と, 長年に渡り触覚を日々活用してきた若年及び高齢の視覚障害者を対象に, 凸バーと凸点の寸法がそれらの識別容易性に及ぼす影響を評価することを目的とした. 参加者に対して, 寸法を厳密に統制した凸バーと凸点の刺激を人差し指で識別させる実験を行った. その結果, 凸バーは, 年齢及び触知経験に関わらず, 長辺と短辺の差が大きいほど早く正確に識別できた. 特に, 若年晴眼者, 若年視覚障害者, 高齢視覚障害者は凸バーの長辺と短辺の差が2.0 [mm] 以上, 晴眼高齢者は3.0 [mm] 以上あれば正確に識別できることが明らかとなった. また, 年齢に関わらず, 視覚障害者はその差が3.0 [mm] 以上, 晴眼者は4.0 [mm] の時に, より早く識別できた. 一方, 凸点は, 年齢及び触知経験に関わらず, 直径が小さく, エッジの曲率半径が大きいほど, 早く正確に識別できることがわかった.</p>

Recently, many tactile guide maps have been installed at various public facilities. Tactile guide map designers have used raised dot patterns to express drawings on a tactile guide map. However, we are lacking quantitative data regarding raised dot patterns for the design of easily understandable tactile maps. In this study, we investigated the influence of dot distances on discrimination of dot patterns used in tactile guide maps by conducting an experiment to find highly discriminable combinations of dot patterns by comparing pairs of dot patterns. The results showed that combinations of dot patterns with a larger difference in dot distances had higher discriminability. When the differences were the same, the combinations of wider dot distances had lower discriminability. Dot patterns with more than 5.0 mm differences in dot distances were highly discriminable for sighted persons, whereas those with more than 4.0 mm differences were highly discriminable for blind persons.

We investigated optimal vibrating conditions for inducing illusory elbow extension movement to develop various practical applications. The experimental factors were the vibration frequency (30, 50, and 70 Hz), vibration amplitude (three phases for each frequency condition), and contact press force (3, 5, 7, 9 N). We subjectively assessed the presence or absence of an illusion, and the vividness on a five-point scale. The results of this study showed that when the vibration amplitude and contact press force became higher than certain values at vibration frequencies of 50 or 70 Hz, the illusion was produced for 80% or more participants, and the vividness of the illusion was increased. Under these stimulation conditions, illusory elbow extension movement can be easily produced; we can develop an interface device that will only provide kinesthetic sensations without the actual motion. Such an interface device can be used for rehabilitation and education fields, and gaming devices.

Recently, touch-sensitive screens have been used for various devices: smartphones, slate PCs, personal media players, etc. Specifically, tablet terminals with a touch-sensitive screen have spread rapidly in the fields of education, medicine, business, etc. However, it has been pointed that their operability is influenced by the difficulty in sliding a fingertip. This study is aimed at examining the influence of the surface condition of the display on the operability of tablet terminals. We measured the coefficients of kinetic friction between the tip of the forefinger and several screen protection films. Our measurements indicate that the coefficient of kinetic friction of anti-glare (AG) film was about one-third that of hard coat (HC) film. Then, we conducted an experiment using these films to evaluate the relationship between the surface condition of the display and the operability. The results show that the surface condition of the display influences the accuracy and speed of operation.

Raised striped-pattern has been used as a drawing expression of tactile guide map. We are lacking in quantitative data regarding raised striped-pattern for designing easily understandable tactile map. In this study, we investigated the influence of interstices among the lines on tactile discriminability of raised striped-pattern. Ten younger persons and thirteen older ones were asked to distinguish the surface roughness according to 4 categories by comparing 10 raised striped-patterns of different interstices among the raised lines, which were prepared on the basis of the results of previous study. From this study, we found that 5.0mm interstice was necessary for distinguishing different surface roughness and those older persons were somewhat inferior to younger persons in sensitivity of surface roughness.

本研究は，歩行中のつまずきやすさに関連すると考えられる，つま先位置の鉛直方向の知覚特性に着目し，被験者本人が知覚しているつま先の位置と，実際のつま先の位置との誤差を定量的に評価した．実験では10 名の若年健常者に対し，足元が見えないように視界が遮蔽された状態で，被験者の3[m] 前方に提示した高さ提示用の試験片と同じ高さまでつま先の高さを合わせるよう指示した．被験者本人が，自分のつま先の高さが試験片の高さと同じになったと感じた時点で実際の高さとの差を計測し，試験片の高さ及び利き足か否かについて恒常誤差を分析した．その結果，試験片の高さが高くなるほど恒常誤差は負の方向に大きくなる傾向が確認された．またこのような傾向は，先行研究で報告されている関節位置覚の知覚特性と一部整合性がとれることも確認された．以上のことから被験者がつま先を高く持ち上げるほど，「自分が思ったよりも足が持ち上がっていない」状態が顕著となる傾向が示唆された．

Recently, touch-sensitive screens have been used for various devices: smartphones, slate PCs, personal media players, etc. Specifically, tablet terminals with a touch-sensitive screen have spread rapidly in the fields of education, medicine, business, etc. However, it has been pointed that their operability is influenced by the difficulty in sliding a fingertip. This study is aimed at examining the influence of the surface condition of the display on the operability of tablet terminals. We measured the coefficients of kinetic friction between the tip of the forefinger and several screen protection films. Our measurements indicate that the coefficient of kinetic friction of anti-glare (AG) film was about one-third that of hard coat (HC) film. Then, we conducted an experiment using these films to evaluate the relationship between the surface condition of the display and the operability. The results show that the surface condition of the display influences the accuracy and speed of operation.

Tactile dots (dot-shaped tactile symbols) placed on the operation keys of consumer products such as cellular phones contribute to improving accessibility for everyone, including persons with visual impairment. JISC (Japanese Industrial Standards Committee) and ISO (International Organization for Standardization) standardized tactile dots and bars. However, sufficient reliable data on the appropriate sizes and cross-section shapes of tactile dots and bars was not necessarily available. Therefore, more quantitative data for optimal dimensions of tactile dots and bars is required to revise existing standards and devise new standards. In this paper, we evaluated influences of the height (0.1, 0.3, 0.55 and 0.75 mm, without tactile dot) 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 in cellular phones. 16 sighted younger participants, whose hand was covered by a curtain, were asked to operate cellular phones with a tactile dot on its key 5 and without tactile dots. As the result, both too high and low height dots are not effective to improve the operational performance of cellular phones and there is an appropriate range of the height of tactile dots regardless of the tip radius of curvature. Furthermore, participants performed better at a particular height with larger tip radius of curvature.

<p>本研究では, 視機能が低下した高齢者及び視覚障害者における消費生活製品の操作性向上に寄与する凸点の高さの条件を明らかにすることを目指し, 携帯電話における操作の仕方と凸点の高さがその操作性に及ぼす影響の関係を評価することを目的とした. 本実験では, 中途失明の一般ユーザーを想定して, 手元を遮蔽した晴眼若年者と晴眼高齢者に対して, 高さが異なる凸点が5番キーに付された携帯電話を, 人差し指による両手操作をさせる実験を行った. さらに, 本実験で新たに収集した人差し指による両手操作の結果と, 先行研究の親指による片手操作の結果を比較することで, 各操作の仕方における凸点の高さが携帯電話の操作性に及ぼす影響の違いを分析した. その結果, 人差し指と親指の各操作において, 若年者と高齢者のいずれも, 凸点の高さが0.3 [mm] の条件は, それよりも高さが低い条件と比べて早く正確に操作した. 一方, 親指による片手操作では, 凸点が0.3 [mm] よりも高くなるにつれて操作時間とエラー率が増加したが, 人差し指による両手操作ではこうした凸点の高さの増加に伴う操作時間とエラー率の増加が認められなかった. これらの結果の相違は, 両手操作と片手操作における手指の動作の違いに起因すると考えられる.</p>

: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.

: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.

Tactile dots (dot-shaped tactile symbols) placed on the operation keys of consumer products such as cellular phones contribute to improving accessibility for everyone, including persons with visual impairment. JISC (Japanese Industrial Standards Committee) and ISO (International Organization for Standardization) standardized tactile dots and bars. However, sufficient reliable data on the appropriate sizes and cross-section shapes of tactile dots and bars was not necessarily available. Therefore, more quantitative data for optimal dimensions of tactile dots and bars is required to revise existing standards and devise new standards. In this paper, we evaluated influences of the height (0.1, 0.3, 0.55 and 0.75 mm, without tactile dot) 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 in cellular phones. 16 sighted younger participants, whose hand was covered by a curtain, were asked to operate cellular phones with a tactile dot on its key 5 and without tactile dots. As the result, both too high and low height dots are not effective to improve the operational performance of cellular phones and there is an appropriate range of the height of tactile dots regardless of the tip radius of curvature. Furthermore, participants performed better at a particular height with larger tip radius of curvature.

To determine the effects of aging on the accuracy of perceived foot position, we conducted following experiment to 10 elderly and 10 young participants. Participants were asked to adjust the position of the target line as close as possible to either most medial or most lateral parts of their foot, while they wore a modified cape that obscured their view of their feet. Once they felt that target line was appropriately placed along the foot, the distance between the line and the foot was measured. No age-related differences were identified when they were asked to place the line along with the most lateral part of their foot. Both age groups tended to place the line 10-20 mm over the foot. However, the elderly displayed smaller errors than young when they were asked to place the line along with the most medial part of their foot. We also discussed the possible reasons that explain these features in the article.

Recently, Transparent-resinous-ultraviolet-curing-type Braille (TRUCT Braille) signs have been spread. However, it has said that TRUCT Braille reading is affected by the friction between forefingers' slipperiness to TRUCT Braille' readability. In previous study, for the purpose of decreasing this friction and enhancing TRUCT Braille readability, we invented a assistive tool of Braille Reading made by polyester non-woven fabric and found that old people with visual impairment wearing it enhances the reading speed and error rate of TRUCT Braille. However, we had to review its material and discuss the fabrication approach. In this study, we compared several materials with polyester non-woven fabric. As a result, we found that sateen weave fabric is better for assistive tool of Braille Reading because of its softness and slipperiness. And we invented fabrication approach of assistive tool of Braille Reading and made its test production.

視力や視野等の視機能が低下した高齢者や視覚障害者における消費生活製品の操作性向上を目的として,製品の操作部に触覚上の目印として付す凸記号表示に関するJIS(S 0011)が2000年に制定された.しかし,このJISの中で推奨されている凸記号の寸法についての客観的なデータは必ずしも十分とはいえず,今後凸記号に関する国際規格(IS)や関連規格の策定及び改訂を検討する上で,凸記号の推奨寸法に関する基礎データが必要とされている.そこで本研究では,このJISで取り上げられている凸点と凸バーの2種類の凸記号が,一つの操作部上で併用される場合に両者が識別可能な寸法を明らかにするために,凸バーと凸点の寸法がそれらの識別容易性に及ぼす影響を評価することを目的とした.具体的には,近年増加傾向にある中途失明者を想定し,手元を遮へいした晴眼若年者及び晴眼高齢者に,短辺と長辺が統制された凸バーと直径が統制された凸点を触覚のみで識別させる実験を行った.本実験の結果,若年者及び高齢者のいずれにおいても,凸バーの短辺の長さにかかわらず,短辺と長辺の差が大きいほど,より速く正確に確信をもって凸バーを識別できることが明らかとなった.

To determine the effects of aging on the accuracy of perceived foot position, we conducted following experiment to 10 elderly and 10 young participants. Participants were asked to adjust the position of the target line as close as possible to either most medial or most lateral parts of their foot, while they wore a modified cape that obscured their view of their feet. Once they felt that target line was appropriately placed along the foot, the distance between the line and the foot was measured. No age-related differences were identified when they were asked to place the line along with the most lateral part of their foot. Both age groups tended to place the line 10-20 mm over the foot. However, the elderly displayed smaller errors than young when they were asked to place the line along with the most medial part of their foot. We also discussed the possible reasons that explain these features in the article.

Recently, many tactile guide maps have been installed at various public facilities with the enactment of "Barrier Free New Law". In tactile guide maps, some tactile symbols have been used for indicating some information items. Japanese Standards Association enacted Standardized Method of Displaying Tactile Guide Maps March 2007 (JIS T0922). Tactile symbols shapes are regulated by the JIS. However, other components of tactile symbol (such as edge, size etc) are unregulated because there are no sufficient research achievements regarding tactile symbols. In this study, for the purpose of investigating influence of tactile symbols edge clarity on their tactile symbols, we compared tactile symbols discriminability in two conditions with tactile symbol edge clarities (acute type (cutting method) and gentle type (screen printing method)). We made tactile symbol test pieces with various sizes by the two methods. And twelve older participants and twelve younger participants were asked to discriminate tactile symbol test pieces. From this study, we found the relation between tactile symbols edge clarity and discriminability of tactile symbols. It was also found that tactile symbols edge clarity influence on their discriminability when the size was particularly small.

To determine the effects of aging on the accuracy of perceived foot position, we conducted following experiment to 10 elderly and 10 young participants. Participants were asked to adjust the position of the target line as close as possible to either most medial or most lateral parts of their foot, while they wore a modified cape that obscured their view of their feet. Once they felt that target line was appropriately placed along the foot, the distance between the line and the foot was measured. No age-related differences were identified when they were asked to place the line along with the most lateral part of their foot. Both age groups tended to place the line 10-20 mm over the foot. However, the elderly displayed smaller errors than young when they were asked to place the line along with the most medial part of their foot. We also discussed the possible reasons that explain these features in the article.

Recently, many tactile guide maps have been installed at various public facilities with the enactment of "Barrier Free New Law". In tactile guide maps, some tactile symbols have been used for indicating some information items. Japanese Standards Association enacted Standardized Method of Displaying Tactile Guide Maps March 2007 (JIS T0922). Tactile symbols shapes are regulated by the JIS. However, other components of tactile symbol (such as edge, size etc) are unregulated because there are no sufficient research achievements regarding tactile symbols. In this study, for the purpose of investigating influence of tactile symbols edge clarity on their tactile symbols, we compared tactile symbols discriminability in two conditions with tactile symbol edge clarities (acute type (cutting method) and gentle type (screen printing method)). We made tactile symbol test pieces with various sizes by the two methods. And twelve older participants and twelve younger participants were asked to discriminate tactile symbol test pieces. From this study, we found the relation between tactile symbols edge clarity and discriminability of tactile symbols. It was also found that tactile symbols edge clarity influence on their discriminability when the size was particularly small.

視覚,聴覚,触覚などの感覚器の中で,触覚は原始的な感覚である.また,視覚や聴覚とは異なり,物に触れる事に基づいた感覚で体感的なものである.心理学の分野では,触れることへの抵抗感と性格の関係が調べられ,モノに触れる抵抗感のある大学生と情緒不安定な大学生の関係に高い相関があるとも言われている.著者は,現代のような視聴覚メディアが中心となった時代において,触覚の重要性に改めて注目し,的確に触覚刺激を活用することは大切なことであると考える.そこで著者は,先行研究において触知覚特性の中で,ヒトが触って直感的に違いがわかる硬さ感覚に注目し,ヒトの指先の硬さ感覚の関係を心理物理実験により調べてきた.本研究では,上述の硬さ感覚知覚の知見を基に,硬さの違いが知覚でき,同時に硬さに応じて音の違いも知覚できる触感と音感を同時に呈示することでユーザがこれまでにない楽しみを体感できるサウンドデバイスを開発した.合わせて,その活用法を提案した.ここでは,開発したサウンドデバイスとその活用法について述べる.

本研究では，障害物にアプローチする方向が，障害物を跨ぎ越える動作に与える影響を評価した．若年成人10 名は，７つの方向（+60, +40, +20, 0, -20, -40, -60 度）から障害物にアプローチし，提示された障害物を跨いで越えるように指示された．各試行では高さの異なる３つの障害物のうち１つ（25mm，50mm，150mm）が提示され，被験者は各条件を5 試行ずつ繰り返した．被験者が障害物を跨ぎ越えた際の動作を三次元動態計測装置で記録し，以下のパラメータを条件間で比較した：つま先クリアランス，歩幅，歩隔，歩行速度．その結果，障害物にアプローチする方向はつまずきの観点からは跨ぎ越え動作に大きな影響を与えないが，バランスの観点からは重大な影響を与えることが示唆された．

点字は点字プリンタや点字タイプライタ等の様々な点字出力器により出力されるが,点字出力器によって触感や触読性は異なると言われている.ここでは,独自に開発した三次元点字形状計測装置を用いて,日米独製の各点字出力器による点字の断面形状やサイズを計測した結果を紹介する.同時に,点字プリンタと断面形状の関係を触察して理解してもらうために製作した点字三次元拡大モデルを紹介する.なお,2009年が点字考案者ルイ・ブライユ生誕200周年であったことを記念して行われた点字ビッグイベントの中で本モデルが展示され,200名を超える方々に点字の断面形状の違いを理解してもらうことができた.

運動障害のある子どもたちがコンピュータを操作しようとする場合,一般のキーボードやマウスでは操作がむずかしい場合が多い.そこで,代替キーボード,代替マウスなどの機器やスイッチによるスキャン入力などが適用されてきた.今回の研究では新たに注目を浴びてきた視線入力システムについて,どのような運動障害のある子どもに対して,適正があるのか,また利用する際にどのような設定をすることが良いか,いくつかの事例を通して検討した.

<p>視覚や聴覚に続く第3の感覚器である触覚に関して, 近年, 触覚のディスプレイ・インタフェースの開発やVR技術への応用を意図した触覚の錯覚 (触錯覚) の知覚心理学的研究がさかんになりつつある. 著者らは, 触錯覚の一つであるベルベットイルージョン (ベルベット感) に着目し, 先行研究で難しいとされた受動触によるベルベット感の呈示の可能性を検討することにした. 本研究では, 受動触によりベルベット感を体感できる触覚のディスプレイ・インタフェースの開発に向けての基礎研究という位置付けで, ベルベット感の発生に影響を及ぼす各因子の条件とその発生率の関係を調べた. 具体的には, ベルベット感の発生に影響を及ぼす各因子の条件をコントロール可能な受動触によるベルベット感評価装置を製作した. そして, その装置を用いて受動触によるベルベット感発生に影響を及ぼす各因子の条件を網羅的に設定し, 各因子の条件でのベルベット感の発生率を実験により調べた. その結果, 各因子について受動触によりベルベット感が発生し易い因子の各条件が明らかになった.</p>

In 2000, a new standard (Japanese Industrial Standard, JIS S 0011) was enacted in Japan. The standard provided the perceptual sizes of tactile dots and bars for use in consumer products. However, the numerical values about these sizes were not determined based on data reliable enough. Therefore, objective and quantitative data for perceptual sizes of tactile dots and bars is required for revising this JIS and for devising other standards. In this study, we focused attention on cellular phones becoming common around the world and evaluated the influence of the height of tactile dots (0.0, 0.1, 0.3, 0.5 and 0.7[mm]) on the operational performance of cellular phone. In this experiment, each 20 sighted younger and older participants, whose hand was covered by a curtain, was asked to operate cellular phones with tactile dot on its key 5 and without tactile dot. Both groups performed better with a tactile dot than without it. However, with a dot height of 0.7mm, participants felt significant pain. We determined that there is an appropriate range of the height of tactile dot that improves the operational performance of cellular phones.

In 2000, a new standard (Japanese Industrial Standard, JIS S 0011) was enacted in Japan. The standard provided the perceptual sizes of tactile dots and bars for use in consumer products. However, the numerical values about these sizes were not determined based on data reliable enough. Therefore, objective and quantitative data for perceptual sizes of tactile dots and bars is required for revising this JIS and for devising other standards. In this study, we focused attention on cellular phones becoming common around the world and evaluated the influence of the height of tactile dots (0.0, 0.1, 0.3, 0.5 and 0.7[mm]) on the operational performance of cellular phone. In this experiment, each 20 sighted younger and older participants, whose hand was covered by a curtain, was asked to operate cellular phones with tactile dot on its key 5 and without tactile dot. Both groups performed better with a tactile dot than without it. However, with a dot height of 0.7mm, participants felt significant pain. We determined that there is an appropriate range of the height of tactile dot that improves the operational performance of cellular phones.

A tactile map is an assistive tool for visually impaired persons to obtain special information. As new barrier-free laws were recently enacted in Japan, many Braille signs and tactile guide maps have been installed in various facilities. Several production methods are available for tactile guide maps. Screen prints have become increasingly popular in Japan because they offer several advantages, including the fact that they can be printed together with visual characters. However, users have one major complaint: screen printing does not create lines and dots on tactile maps, thus necessitating improvement in screen printing performance. In this study, we developed a new tactile map production device as an alternative to screen printing devices. Also, a tactile map created by our method included a vocal guidance function based on users&apos; needs. We found that the finished-print performance and convenience of tactile maps improved considerably. This study will be useful in providing a new style for future tactile maps.

When touching an object, the forefinger pad is deformed based on the hardness of the object, and we consider that slight deformation influences hardness sensation. To clarify the influence of deformation of forefinger pad on hardness sensation, we compared hardness sensation in two conditions with different deformation of the forefinger pad by the method of successive categories. Fourteen elastic test pieces with different hardness were evaluated by eleven subjects based on seven stages of hardness sensations (extremely soft, fairly soft, slightly soft, neither, slightly hard, fairly hard, extremely hard) for the conditions of direct touching of test pieces or touching using an acrylic plate. This results indicated that subjects were capable of perceiving slight differences in hardness within three categories (fairly soft, slightly soft, and fairly hard) for direct rather than indirect touch. Deformation of the forefinger pad based on the hardness of an object may thus influence hardness sensation when the hardness of an elastic object is classified into these three categories.

Recently, environment that visually impaired persons are capable of getting electric information is being developed. By using Braille display, visually impaired can get various electrical information on network. Therefore, Braille display rapidly spread in the foreign and domentic country. However, when Braille display is used continually, the base material of Braille display becomes worn. It has been pointed out that Braille readers find it difficult to read Braille on worn base material which their forefingers cannot slide easily. In this study, to reduce this friction, we reinvent a thin low friction film cover on worn base material to reduce friction during Braille reading. And also we carried out a study to investigate influence of base material features of Braille display on Braille reading and the effect of its use. We compared the discriminability of Braille when covering two films with excessive and less kinetic friction on the base material. As the results, subjects could read Braille significantly faster and more correctly when less kinetic friction film (powder compounded film) cover was used on the base material. In short, by use of powder compounded film cover, we found that Braille readers' forefingers can slide easily and discriminability of Braille was improved. From this study, we suggest the covering less friction this film on Braille display with worn base material as method of being able to improve the discriminability of Braille.

Tactile ground surface indicators installed on side-walks help visually impaired people walk safely. The Visually impaired distinguish the indicators by stepping into its convexities and following them. However, these indicators sometimes cause the. nonvisually impaired to stumble. This study examines the effects of these indicators by comparing. the kinematic and kinetic variables of walking on paths with and without indicators. The results suggest that walking on the indicators causes extra movements of the lower extremities such as increased minimum toe heights during the midswing phase, increased peak hip flex moments, and increased peak hip heights. This study also suggests that a functional leg length discrepancy while walking on the indicators is one of the reasons for the extra movements of the lower extremities. Therefore, we designed a new recessed tactile surface to offset the differences of surface depth while walking on the path containing indicators, and found that the newly designed recessed tactile surface was effective in reducing the extra movements while walking on the path in which indicators were installed. These indicators may help both the visually impaired and elderly people with normal vision to walk safely.

点字は, 視覚障害者の文字として最もポピュラーな視覚代行手段である. しかし点字識字率は低く, その背景には, 点字が小さいため読みとりにくく, 点字の習得が困難であるという問題がある. 現在製品化されている点字プリンタなどはその機種によって様々な点の形状や高さをもつ. しかしこの点字パターンが触読に影響を及ぼすことが知られており, 使用機種によって読みやすさに違いが出てくる. そこで本研究では, 初心者に読みやすい点字パターンを明らかにするため, 点の断面形状・高さ・間隔が識別容易性に与える影響を調べた. 実験には点字触読経験のない晴眼者に参加してもらい, 3つの因子を任意に組み合わせた様々な点字パターンでの弁別課題を行った. 実験の結果, 断面形状によって, 高さの効果と点間隔の効果がそれぞれ異なり, 各因子がそれぞれ識別容易性に影響することが示された. これは, 読みやすい点字に対して有用なデータとなりうると思われる.

The purpose of this study was to compare the effect between cyclists and noncyclists of pedal rates on ankle, knee, and hip joint torque during pedaling exercises.Six male cyclists (CY) and seven male noncyclists (NC) pedaled at 40, 60, 90 and 120 rpm with a power output of 200W.The lower limb was modeled as three rigid segment links constrained to plane motion.Based on the Newton-Euler method, the equation for each segment was constructed and solved on a computer using pedal force, pedal, crank, and lower limb position data to calculate torque at the ankle, knee, and hip joints.The average planter flexor torque decreased with increasing pedal rates in both groups.The average knee extensor torque for CY decreased up to 90 rpm, and then leveled off at 120 rpm.These results were similar to NC.The average knee flexor torque in both groups remained steady over all pedal rates.The average hip extensor torque for CY decreased significantly up to 90 rpm where it showed the lowest value, but increased at 120 rpm.For NC, the average hip extensor torque did not decrease at 90 rpm compared with 60 rpm, and was significantly higher than CY at 120 rpm(CY:28.1±9.0Nm, NC:38.6±6.7Nm, p<0.05).The average hip flexsor torque for NC at 120 rpm increased significanly from 90 rpm, and was significantly higher than CY(CY:11.6±2.9Nm, NC:22.6±11.8Nm, p<0.05).These results suggest that it would be better for cyclists to select a pedal rate of between 90 to 110 rpm to minimize joint torque, and, as a result, reduce peripheral muscle fatigue.