Characteristics of Information Transmission Rates Using Noncontact Tactile Display Kentaro Kotani, Masayoshi Hayashi, Nobuki Kido, and Takafumi Asao Department of Mechanical Engineering, Kansai University
[email protected]
Abstract. Recently, tactile interfaces, which are user interfaces that employ tactile perception for input/output, have been the focus of an increasing number of studies. However, tactile interface design guidelines to help optimize the characteristics of human tactile perception have not yet been fully developed. Thus, the objective of the study was to identify the influence of perception of phantom sensation on the location of stimulus presentation on the palm. For this purpose, a noncontact tactile display with an independent driven 12 by 12 matrix air-jet driver was constructed. The subjects orally responded one of following three perception levels, i.e., (1) a crisp phantom sensation was obtained, (2) incomplete phantom sensation was perceived due to scattered stimuli, and (3) only separate stimuli were perceived and no integrated perception was generated. Phantom sensation was perceived apparently at the proximal side of the index finger compared to the wrist areas. The obtained topography drastically changed between subjects, suggesting that each individual has different distribution of perceived phantom sensations. Future study included the range of securely perceived phantom sensations for determining the specifications of tactile displays.
1 Introduction Tactile interfaces, which are user interfaces that employ tactile perception for input/output, have been the focus of an increasing number of studies. However, tactile interface design guidelines to help optimize the characteristics of human tactile perception have not yet been fully developed. It was indicated that the fundamental characteristics of tactile interface design are not properly understood [1]. Especially, we have been studied the characteristics of phantom sensation for tactile display, where a total of eight different shapers were identified with a less than 10 percents of error rates [2]. The individual differences varied although the same location of the palm was carefully arranged for the appropriate tactile stimulus presentation. It should be good to know the distribution of accurate perception of tactile stimuli by individuals which may offer quantitative specification for the design of tactile displays. Thus, the objective of the study was to identify the influence of perception of phantom sensation on the location of stimulus presentation on the palm. M.J. Smith, G. Salvendy (Eds.): Human Interface, Part I, HCII 2011, LNCS 6771, pp. 450–453, 2011. © Springer-Verlag Berlin Heidelberg 2011
Characteristics of Information Transmission Rates Using Noncontact Tactile Display
451
2 Methods A noncontact tactile display with an independent driven 12 by 12 matrix air-jet driver was constructed as shown in Figure 1. Pressurized air was generated by an air compressor and delivered using solenoid valves. The air pressure was then regulated using a series of electro-pneumatic regulators. The intensity of the air-jet stimuli was controlled at 100kPa, and stimuli were applied to the center of the left palm. A total of six subjects consented to participate in the study. All of them were recruited from the university community and were right-handed. The tested area consisted of 81 locations of the palm (see Figure 2), each of which was generated by using phantom sensations consisted of stimuli generated by three independent nozzles. There were five trials for each location. The subjects orally responded one of following three
50mm
Fig. 1. Contactless tactile display (Left: system apparatus, Right: the display part where independent 144 air-jet nozzles were attached under the 50mm by 50mm-metal plate)
Fig. 2. Location of stimuli presentation given by phantom sensation. A total of 81 locations were chosen. The top middle point was aligned at the center point between the MP joint of the index finger and the MP joint of the little finger. Nine different symbolic patterns denote the regions tested as a location effect for statistical analysis.
452
K. Kotani et al.
perception levels, i.e., (1) a crisp phantom sensation was obtained, (2) incomplete phantom sensation was perceived due to scattered stimuli, and (3) only separate stimuli were perceived and no integrated perception was generated. Topography of perception of phantom sensation was generated for the individual to identify the tendency of the distribution of clearness of phantom sensation. The topography consisted of 255 levels of gradations ranging from white (no PS) and black (crisp PS).
3 Results A two-way ANOVA was conducted to see the effects of subjects and the locations on the perception of tactile phantom sensations. The results revealed that significant individual differences F(8, 432) = 5.810, p
