E nose


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Electronic nose is an emerging tech in IT field...


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Contents Introduction History Working principle Design model Comparison of biological nose & enose Applications Advantage of enose over human nose Conclusion Reference

Introduction :

Introduction An electronic nose (e-nose) is a device that identifies the specific components of an odor and analyzes its chemical makeup to identify it. An electronic nose consists of a mechanism for chemical detection, such as an array of electronic sensors, and a mechanism for pattern recognition. Electronic noses were originally used for quality control applications in the food, beverage and cosmetics industries. Current applications include detection of odors specific to diseases for medical diagnosis, and detection of pollutants and gas leaks for environmental protection.

History :

History E -nose was frst suggested by Julian Gardner of Warwick University in1988 (Gardner, 1988) and came into popular use after a 1989 NATO conference on the subject. Sincethen, development of sensor array–based instruments has been actively pursued in Asia, North America,and Europe. Using instruments based on sensor arrays, the low selectivity of many types of chemical sen-sors can sometimes be resolved, though at the cost of using an array of reversible but only semiselectivedetection layers with diferent chemical properties. An e-nose has been defned as “an instrument which comprises an array of electronic chemical sensors with partial specifcity and an appropriate pattern rec-ognition system, capable of recognizing simple or complex odours” (Gardner and Bartlett 1994).

Working principle :

Working principle The electronic nose was developed in order to mimic human olfaction that functions as a non-separative mechanism: i.e. an odor / flavor is perceived as a global fingerprint. Essentially the instrument consists of head space sampling, sensor array, and pattern recognition modules, to generate signal pattern that are used for characterizing odors. Electronic noses include three major parts: a sample delivery system, a detection system, a computing system. The sample delivery system enables the generation of the headspace (volatile compounds) of a sample, which is the fraction analyzed. The system then injects this headspace into the detection system of the electronic nose. The sample delivery system is essential to guarantee constant operating conditions. The detection system, which consists of a sensor set, is the “reactive” part of the instrument. When in contact with volatile compounds, the sensors react, which means they experience a change of electrical properties. Each sensor is sensitive to all volatile molecules but each in their specific way. Most electronic noses use sensor arrays that react to volatile compounds on contact: the adsorption of volatile compounds on the sensor surface causes a physical change of the sensor. A specific response is recorded by the electronic interface transforming the signal into a digital value. Recorded data are then computed based on statistical models . [5]

Design model :

Design model

Comparison of biological nose & enose :

Comparison of biological nose & enose

Comparison of Enose with Biological nose :

Comparison of Enose with B iological nose Biological nose Enose 10 million receptors, self generated 5-100 chemical sensors manually replaced 10-100 selectivity classes 5~100 selectivity patterns Initial reduction of number of signals “smart” sensor arrays can mimic (~1000 to1) this? Adaptive Perhaps possible Saturates Persistent Signal treatment in real tim Pattern recognition hardware may do this Identifies a large number of odour Has to be trained for each Cannot detect some simple molecules Can detect also simple molecules (H2, H20, C02 )


Applications Electronic nose for enviromental monitoring Enormous amounts of hazardous waste (nuclear, chemical, and mixed wastes) weregenerated by more than 40 years of weapons production in the U.S. Department of Energiesweapons complex. The Pacific Northwest National Laboratory is exploring the technologiesrequired to perform environmental restoration and waste management in a cost effective manner.This effort includes the development of portable, inexpensive systems capable of real- timeidentification of contaminants in the field. Electronic noses fit this category .. Electronic nose used in detection of bombs The tragic bombings in London on the 7 July 2005 have caused many to call for bagsearching at the ticket barriers on the Underground. This would cause huge delays, apart fromfinding the manpower to do it. A possible alternative is using an “electronic nose” to sniff out possible explosives so that only selected bags need to be searched by staff. The concept has beenaround for a long time, and was initially ridiculed. The basic idea is a device that identifies thespecific components of an odour and analyzes its chemical makeup to identify it. One mechanism would be an array of electronic sensors would sniff out the odours while a secondmechanism would see if it could recognize the pattern.

PowerPoint Presentation:

Electronic nose for multimedia Aaplication Multimedia systems are widely used in consumer electronics environments today, wherehumans can work and communicate through multi-sensory interfaces. Unfortunately smelldetection and generation systems are not part of today's multimedia systems. Hence we can useelectronic nose in multimedia environment. Electronic nose for medicine Because the sense of smell is an important sense to the physician, an electronic nose hasapplicability as a diagnostic tool. An electronic nose can examine odors from the body (e.g., breath, wounds, body fluids, etc.) and identify possible problems. Odors in the breath can beindicative of gastrointestinal problems, sinus problems, infections, diabetes, and liver problems.Infected wounds and tissues emit distinctive odors that can be detected by an electronic nose.Odors coming from body fluids can indicate liver and bladder problems. A more futuristicapplication of electronic noses has been recently proposed for telesurgery.

Advantage of enose over human nose :

Advantage of enose over human nose The human sniffers are costly when compared to electronic nose. It is because these people have to be trained. This is a time consuming that a construction of an electronic nose. Now for the confirmation of the values obtained from a sniffer the result obtained from the sniffer has to be compared with some other sniffer’s value. And here there are great chances of difference in the values got by each individual. Detection of hazardous or poisonous gas is not possible with a human sniffer. Thus taking into consideration all these cases we can say that electronic nose is highly efficient than human sniffer

Conclusion :

Conclusion Humans are not well suited for repetitive or boring tasks that are better left to machines. No wonder the electronic nose is sometimes referred to as a "sniffer". The E-nose has theinteresting ability to address analytical problems that have been refractory to traditional analytical approaches. gospel is a European network of excellence in Artificial Olfaction.In my view the electronic nose is a very useful instrument now a days.

Reference :

Reference WWW



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