Pattern Recognition and Multicomponent Analysis

Hierlemann, Andreas; Schweizer-Berberich, M.; Kraus, Gerolf; Pfau, A.; Göpel, Wolfgang

doi:10.1002/1616-8984(199610)2:1<119::aid-seup119>3.0.co;2-6

Cited by 57 publications

(38 citation statements)

References 115 publications

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“…They involve reactions with oxygen on the sensor surface, which lead to a change of the free charge carrier concentrations in the conducting metal oxide. Advantages of these sensors are high sensitivities (14) and long duration (15). The sample's headspace (volume of 3 ml) is carried through the measurement chambers of the modules sequentially.…”

Section: Methodssupporting

confidence: 44%

“Electronic nose” detects major histocompatibility complex-dependent prerenal and postrenal odor components

Montag

Frank

Ulmer

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

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Mice prefer to mate with individuals expressing different MHC genes from their own. Volatile components presenting MHCdependent odor types are present in urine and can be detected by mice, as shown by extensive behavioral studies. Similar odor types are suspected to influence human behavior as well. Although a recent report indicates that MHC expression influences the ratio of volatile compounds such as phenylacetic acid, so far no other means than studying the behavior of mice or rats has been available to assess odor types. Here, we report the ability of a gas sensor array (referred to as ''electronic nose'') to detect MHCdependent odor types. The electronic nose consists of an array of chemophysical detectors, in our case quartz crystal microbalances and semiconducting metal-oxide sensors that change frequency or conductivity upon binding of very small numbers of individual molecules present in the gas phase of odorous fluids. The pattern of changes is characteristic for a particular smell. Our electronic nose distinguishes the urine odor types of MHC congenic mouse strains, MHC class I mutant mice, and HLA-A2 transgenic mice. In addition, MHC-dependent odor types can be detected in serum. The device also clearly differentiates between individual odor types of human sera from HLA homozygous individuals; however, HLA expression seems to have only a secondary influence. Thus, odor-type research can now be carried out with an objective and fast through-put system independent of behavioral studies.T he principal function of MHC molecules is to present peptides to T cells (1). MHC class I molecules are expressed on the cell membrane of almost all somatic cells. Typically, MHC I molecules present virus-derived peptides of 8-11 aa to virus-specific cytotoxic T cells. MHC class II molecules are expressed on a subset of cells only, most notably on B cells, dendritic cells, and macrophages. Typically, T-helper cells recognize peptides of 12-25 aa derived from antigen presented on B cell MHC II molecules (2). This induces the T cells to produce signals that activate the B cell to produce antibody. MHC I and II molecules have well-defined peptide receptor specificities that enable binding of peptides with certain sequence patterns. MHC genes are extremely polymorphic; there are, for example, more than 180 alleles at the HLA-B locus (3). This polymorphism is reflected in different peptide receptor specificities for each of the allelic products (4). In consequence, T cells from different individuals recognize a different selection of antigen peptides from the very same pathogen. Thus, pathogens can mutate their MHC-presented peptide sequences to escape T cell recognition in an individual; the same mutations, however, are useless for the pathogen in other individuals with different MHC expression. The extreme polymorphism is, therefore, assumed to have evolved to avoid pathogen escape from immune recognition on the species level (5).A driving force for establishment and maintenance of MHC polymorphism is probably the ''surv...

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Section: Methodssupporting

confidence: 44%

“Electronic nose” detects major histocompatibility complex-dependent prerenal and postrenal odor components

Montag

Frank

Ulmer

et al. 2001

Proc. Natl. Acad. Sci. U.S.A.

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“…Pattern recognition in multisensor devices is a known technique [5], also for measuring multicomponent compounds [4], but now a new sensing method is introduced by combining the vibrating capacitor Kelvin measurement with backpropagation feedforward neural network.…”

Section: Introductionmentioning

confidence: 42%

Vibrating capacitor mapped chemical picture classification by artificial neural network

Császár

Mizsei

2005

Thin Solid Films

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“…Further, the integration of gas sensor arrays on a chip, the use of multicomponent analysis algorithms, such as principal component regression (PCR) or artificial neural networks (ANN), and the application of new dynamic sensor operation modes [24], [25] help to overcome the problems associated with poor selectivity and drift of individual gas sensors [26].…”

Section: Introductionmentioning

confidence: 44%

CMOS Monolithic Metal–Oxide Gas Sensor Microsystems

et al. 2006

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This paper presents two mixed-signal monolithic gas sensor microsystems fabricated in standard 0.8-m CMOS technology combined with post-CMOS micromachining to form the microhotplates. The on-chip microhotplates provide very high temperatures (between 200 C and 400 C), which are necessary for the normal operation of metal-oxide sensing layers. The first microsystem has a single-ended architecture comprising a microhotplate (diameter of 300 m) and a digital proportional-integral-derivative (PID) microhotplate temperature controller. The second microsystem has a fully-differential architecture comprising an array of three microhotplates (diameter of 100 m) and three digital PID microhotplate temperature controllers (one controller per microhotplate). The on-chip digital PID temperature controllers can accurately adjust the microhotplate temperatures up to 400 C with a resolution of 2 C. Further, both microsystems feature on-chip logarithmic converters for the readout of the metal-oxide resistors (which cover a measurement range between 1 k and 10 M ), 10-bit A/D converters, anti-aliasing filters, 10-bit D/A converters, 2 serial interfaces, and bulk-chip temperature sensors. Carbon monoxide (CO) concentrations in the sub-parts-per-million (ppm) range are detectable, and a resolution of 0.2 ppm CO has been achieved.Index Terms-CMOS-based microsystem, MEMS, metal-oxide gas sensors, PID control.

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Pattern Recognition and Multicomponent Analysis

Cited by 57 publications

References 115 publications

“Electronic nose” detects major histocompatibility complex-dependent prerenal and postrenal odor components

“Electronic nose” detects major histocompatibility complex-dependent prerenal and postrenal odor components

Vibrating capacitor mapped chemical picture classification by artificial neural network

CMOS Monolithic Metal–Oxide Gas Sensor Microsystems

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