TABLE OF CONTENTS Olfaction is the sense related to smell, and olfactory interfaces refer to devices and/or systems that provide users with information through smells. Olfaction is categorized as a kind of "special sensation," for humans have a dedicated sensing organ to detect the stimuli. Humans perceive smell by detecting certain molecules in inspired air via the olfactory organ in the nose.
The olfactory interface is a relatively novel device. In modern computer systems, visual and auditory interfaces are highly developed, and there are numerous ways for users to obtain information through visual and auditory channels. Recently, haptic interfaces have been actively developed such that, in certain environments, users are able to touch and feel virtual objects or environments. Among the so-called "five senses," only olfaction and gustation (sense of taste) have been left unexamined. These unexploited sensations are chemical senses, whereas the relatively well-developed sensory interfaces (visual, auditory, and haptic) are related to physical stimuli. This fact makes it difficult to introduce olfactory and gustatory interfaces in a similar manner to sensory channels based on physical stimuli. However, researchers have recently begun to actively discuss and develop the use of olfactory interfaces, including the introduction of an olfactory display in virtual-reality (VR) systems (Barfield & Danas, 1996), and transmitting olfactory information over telecommunication lines (Davide et al., 2001).
Figure 8.1(a) shows the structure of the human nose. In the nasal cavity, there are three nasal turbinates separating the path of the air flow in the...
