Tactile sense

Flavor has been defined as a memory and an experience (1). These definitions have always included as part of the explanation at least two phenomena, ie, taste and smell (2). It is suggested that in defining flavor too much emphasis is put on the olfactory (smell) and gustatory (taste) aspects (3), and that vision, hearing, and tactile senses also contribute to the total flavor impression. Flavor is viewed as a division between physical sense, eg, appearance, texture, and consistency, and chemical sense, ie, smell, taste, and feeling (4). The Society of Flavor Chemists, Inc, defines flavor as "the sum total of those characteristics of any material taken in the mouth, perceived principally by the senses of taste and smell and also the general senses of pain and tactile receptors in the mouth, as perceived by the brain" (5). 

It is difficult to define unequivocally the quality of fabric handle or softness/firmness differences, since this involves many factors. It is often linked with lubrication, especially as similar products are often used for softening and lubrication. Whilst experienced assessors can be quite remarkable in the extent to which they can grade and assess softeners simply by means of a highly developed tactile sense, more objective methods are clearly desirable for scientific investigations. Since many factors combine in producing an overall sense of softness, it is not surprising that objective determination of softness involves more than one parameter of measurement. The details of assessment are outside the scope of this chapter, but descriptions and discussions are available elsewhere [478-481]. Suffice it to say here that the Kawabata system has acquired considerable importance in quantifying various aspects of fabric handle. 

In contrast to a typical industrial robot, the laboratory robot must be flexible and user-programmable. Many laboratory robots incorporate tactile sensing and other verification methods. However, vision capabilities are virtually nonexistent at this time. Laboratory robots range in price from 25,000- 100,000 with typical system prices averaging 40, 000- S0,000. 

This curious notion of the nature of the elements and the fact that there are just four elements in the terrestrial zone of the universe, Aristotle arrives at somewhat in this way. The only absolute criterion of the existence of matter is the sense of touch. Sight and hearing are subjective phenomena dependent upon our senses, liable to errors of interpretation. The phenomena which affect the tactile sense may be analyzed into four elements, hot and cold, moist and dry. All other properties, color, odor, roughness, smoothness, he asserts are either nonessential or combinations of these four. From these four properties there may be made six pairs ... 

Fig. 5.30 View of textured cinch, cross-hatched, to assist a soldier in darkness where only tactile sensing is necessary to operate the tourniquet...

Moss-Salentijn, L. (1992) The Human Tactile System, em Advanced Tactile Sensing for Robotics. Editor H.R.Nicholls Chapter4 World Scientific Publishing, Singapore... 

The tactile sense is probably the most basic of all senses, and there are very few life forms on Earth, however simple, that do not respond in some way to being touched. Intelligent aliens would have additional senses it seems unlikely that a complex and intelligent creature could evolve with one sense alone. These additional senses are needed to confirm and refine an intelligent creature s perception of the immediate environment. This means that other senses are likely to accompany the sense of touch. 

I have been told that 9 out of 10 men don t have intercourse on MDMA. That s perhaps their psychology we [my partner and I] always have intercourse. I find males can sustain their erection for the full trip if they wish — but neither sex has orgasms (the male doesn t ejaculate), so the male can continue. Skin tactile sense is 3 to 4 times more sensitive and wonderful—and after several trips one learns to recreate that enhanced tactile sense at will, without tripping. 

In this category belong the properties that determine the reactions (perceptions) of the senses the eye (colour, lustre, covering power, appearance), and the tactile sense, viz. the tactile corpuscles of the skin (handle). While the aesthetic properties are influenced by the intrinsic properties, they depend much more on the "added" properties, that is to say on those obtained during processing, as is clearly shown in Table 27.1. The correlation of the aesthetic properties with the intrinsic and added properties is very complex and only partly understood. As matters stand at present, they are more qualitative than quantitative. The main aesthetic properties are considered below. 

Prolonged TCE exposure has been associated with impairment of peripheral nervous system function, persistent neuritis and temporary loss of tactile sense and paralysis of the fingers after direct solvent contact. Chromosomal effects have been reported in those involved in the use of TCE for degreasing and symptoms of systemic lupus erythematosis have been reported after chronic TCE exposure. In addition, organic dementia has been noted after occupational exposure to TCE and there have been some reports of an association between exposure and scleroderma, an autoimmune disease. 

Winquist, R, Wide, P, Eklov, T., Hjort, C., and Lundstrom, I. Crispbread quality evaluation based on fusion of information from the sensor analogies to human olfactory, auditory and tactile senses, /. Food Process Eng., 22, 337, 1999. 

Obviously, reproducing the human sense of touch with an artificial system is a very challenging task, primarily, because the term touch is actually the combined term for several senses. Research and development on tactile sensing has experienced an impressive growth in the last three decades, and several kinds of materials and techniques have been proposed. The tentative specifications for tactile sensors have been defined [54] as ... 

I had been drinking probably excessively the last two days, and maybe the body needed to unpoison itself. The tactile sense is beautiful, but there seems to be some numbness as well, and I feel that nothing erotic would be do-able. Intimacy, yes, but no performance I m pretty sure. I saw the experience start drifting away only four hours into it, and I was sad to see it go. It was an all around delightful day. 

The main elements of VE interfaces are displays that mediate visual, acoustic, and tactile sense stimuli. Of essential significance are visual and acoustic displays. 

Geldard [1960] and Sherrick [1973] lamented that as a communication channel, the tactile sense is often considered inferior to sight and hearing. However, the tactile system possess some of the same spatial and temporal attributes as both of the primary senses [Bach-y-Rita, 1972]. With over 10,000 parallel channels (receptors) [Collins and Saunders, 1970], the tactile system is capable of processing a great deal of information if it is properly presented. 

Tactile rehabilitation has received minimal attention in the literature or medical community. One research device sensed pressure information normally received by the fingertips and displayed it on the forehead using electrotactile stimulation [ Collins and Madey, 1974]. Subjects were able to estimate surface roughness and hardness and detect edges and corners with only one sensor per fingertip. Phillips [1988] reviews prototype tactile feedback systems that use the intact tactile sense to convey hand and foot pressure and elbow angle to users of powered prosthetic limbs, often with the result of more precise control of these devices. 

Szeto, A.Y.J. and Riso, R.R. 1990. Sensory feedback using electrical stimulation of the tactile sense. In R.V. 

With sufficient training, people without useful vision can acquire sufficient information via the tactile sense for many activities of daily living, such as walking independently and reading. The traditional... 

More sophisticated instrumentation also capitalizes on the spatial capabilities of the tactile sense. The Optacon (optical-to-tactile converter) by TeleSensory, Inc. (Mountain View, Calif.) converts the outline of printed letters recorded by a small, hand-held camera to enlarged vibrotactile letter outlines on the user s fingerpad. The camera s field of view is divided into 100 or 144 pixels (depending on the model), and the reflected light intensity at each pixel determines whether a corresponding vibrating pin on the fingertip is active or not. Ordinary printed text can be read at 28 (typical) or 90 (exceptional) wpm. 

When the mechanical resistance of the obstacle exceeds the mechanical energy produced by the device, the device is unable to shift the obstacle and the muscle potential steps to very high values at the moment of contact. So we have a muscle with tactile sense quite simple response-analysis software can transform the ensemble (computer, potentiostat, and device) into a conscious system. The system indicates when a muscle, or the mechanical tool driven by the muscle, touches an obstacle and how much mechanical resistance the obstacle opposes. 

Howe, R. D., and M. R. Cutkosky, Dynamic Tactile Sensing Perception of Fine Surface Features with Stress Rate Sensing, IEEE Trans. Robotics Automation, 1993, 9(2) 140-151. 

The tactile sense handles less information than audition. Humans can discriminate accurately among limited shapes and textures through touch. 

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