Haptic sensations

During the demonstration visit (interface 1) the body is used as a way for the decision-maker to experience the effect of the vibrotactile stimuli and customise the fabric structure. Similarly, the family member has a chance to experience interaction with the pillow in an introduction session (interface 3). When the pillow is used during the visit (interface 5), the exploration of the bodily somaesthetic qualities opens up opportunities for social interaction. Further, the vibrotactile stimuli patterns and haptic sensations have a direct relation to the movements of the body. This principle makes it possible for even people with limited cognitive capabilities to still have an activity... 

Besides nutrients, foods contain many substances that influence the food sensory impression and its organoleptic properties. These food constituents are known as sensoriaUy active compounds. They determine the sensory value (quality) of foods, inducing an olfactory sensation (perception), which is described as the aroma, odour and smell, gustative perception, which is the taste, visual perception, which is the colour, haptic (tactile) perception, which is the touch and feel, and auditorial perception, which is the sound. The olfactory sensation is derived from odour-active compounds and the gustative perception from taste-active compounds. Flavour is the sensory impression determined by the chemical senses of both taste and smell and is caused by flavour-active food components. Haptic sensation is the texture, which is affected mainly by high molecular weight compounds, such as proteins and polysaccharides, often referred to collectively as hydrocoUoids. Geometric aspects of texture that evoke both haptic and visual sensations symbolise the terms appearance and shape. 

The properties included under the heading texture are found mainly in macromolecular food components, especially proteins and polysaccharides, as well as products of their interactions and associations with other food ingredients, first and foremost with water. Texture impHes those characteristics of foods that cause tactile or haptic sensations registered by receptors in the oral cavity. Touch by hands is very important. Auditorial perceptions such as crispness are related to a range of textural characteristics. Geometric attributes of texture that simultaneously cause visual and haptic sensations, often referred to as shape and appearance (such as particle size or size of the whole food), are closely related to food colour. The term consistency describes the texture aspects related to physical (mechanical) properties of food, which are also called rheological properties (see Section 7.8.4.1). 

Actuator for haptic sensation, e.g. trembling steering wheel or seat... 

Haptic displays may distract the driver s attention because the reason of the haptic sensation is often not clear. A tremble may, for instance, be misinterpreted as a technical defect like a flat tire. For these reasons haptic displays are not recommended. 

The flavour of a food consists of odour, taste, and haptic and tactile sensations in the mouth ( mouthfeel ) (Fig. 3.52). This means that a flavour modifier may affect odour, taste, and/or mouthfeel of a food. Usually, only taste and/or odour are affected, although maltol and ethyl maltol have been reported to be effective in improving the mouthfeel in low-fat food systems [7]. Because of lack of a clear definition, I shall classify flavour modifiers into the five categories shown in Table 3.46. Based on this... 

Haptics Touch screens Joysticks Data gloves Enables users to communicate with touch and obtain information in the form of felt sensations... 

The visual perception of depth (when viewing 3D) data is helped enormously if the viewer can move the data himself. There are many depth cues (stereo, depth from motion, depth from perspective), but depth from motion is the strongest. That is why maximum intensity projections (MIP) are preferably viewed dynamically. By self-tracking also the muscle s proprioceptors are giving feedback to the brain, adding to the visual sensation. The combination with human s superb eye-hand coordination has led to the concept of the Dextroscope (www.dex-troscope.com), where a (computer generated) view or object can be manipulated under a half-transparent mirror, through which the viewer sees the display. Displays can also be equipped with haptic (tactile) feedback systems, which are now commercially available (Fig. 9.13). 

Tactile sensation is an important cue for us to find a subtle difference in handling objects. For a robotic telemanipulation surgery, tactile displays, which produce virtual cutaneous sensation on human hands, provide haptic feedback to the operators for finding diseases carefully and manipulating tools dexterously. For virtual reahty apphcations in medicine, such as rehabilitation and psychotherapy, a tactile display can also contribute to human emotional responses because tactile sensation is highly related to both our comfort and wonder. Many researchers have developed tactile displays and haptic interfaces, as reported by Benali-Khoudja [1] and Hayward [2]. However, it is difficult for conventional tactile displays to synthesize rich and complex tactile sensation arbitrarily. 

Biggs J, Srinivasan M (2002b) Tangential versus normal displacements of skin relative effectiveness for producing tactile sensations. In Proceedings of 10th symposium on haptic interfaces virtual environ teleoperator systems HAPTICS, Orlando, pp 121-128... 

---