Optimization Of Portable E-Nose And Its Applications In Breath And Food Detection

Now e-Nose is tending to be intelligent and portable with wider applications in various fields. Breath diagnosis of disease and food freshness detectionareimportant applicationsof e-Nose. And comparing with traditional methods, these two ways turn out to be fast, non-invasive and low-cost.For the purpose of employing e-Nose into breath and food detection, this thesis not only optimized the CN e-Nose Ⅱ to be more portable, but also designed an e-Nose for food freshness detection. Thisthesismainly contains:1. The work about gas sampling. According to the different sampling needs in breath and food detection, two specific designs have been carried out. A field sampling apparatus for breath collection has been fabricated, which achieves a fast, non-invasive, automated breath sampling. And as to food freshness detection, a proper method for food volatile sampling is also carried out.2. Optimization of CN e-Nose Ⅱ. The purpose of optimization is making it into a moreportable one. So the design mainly involves the optimization of MOS sensorarray, gas and electric circuits, as well as the introduction of network module.3. Prototype design of food detection e-Nose. A food freshness evaluation system is built based on food volatiles. And a specific MOS sensor array is selected according to the volatiles of food spoilage. In addition, an initial design about the combination of food detection e-Nose with refrigerator is proposed.4. Evaluation of two e-Noses. A calibrating experiment was carried out for both breath and food detection e-Nose. Then clinical test based on13patients with lung cancer and14healthy controls reflects the early diagnostic model has an accuracy of77.8%. And a new diagnostic model has83.2%sensitivity and79.5%specificity. What’s more, the freshness test shows the food detection e-Nose has a good performance in food freshness discrimination, as well as in the discriminationof4flesh food types.