by Keyword: Instruments

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Oller-Moreno, S., Pardo, A., Jimenez-Soto, J. M., Samitier, J., Marco, S., (2014). Adaptive Asymmetric Least Squares baseline estimation for analytical instruments SSD 2014 Proceedings 11th International Multi-Conference on Systems, Signals & Devices (SSD) , IEEE (Castelldefels-Barcelona, Spain) , 1569846703

Automated signal processing in analytical instrumentation is today required for the analysis of highly complex biomedical samples. Baseline estimation techniques are often used to correct long term instrument contamination or degradation. They are essential for accurate peak area integration. Some methods approach the baseline estimation iteratively, trying to ignore peaks which do not belong to the baseline. The proposed method in this work consists of a modification of the Asymmetric Least Squares (ALS) baseline removal technique developed by Eilers and Boelens. The ALS technique suffers from bias in the presence of intense peaks (in relation to the noise level). This is typical of diverse instrumental techniques such as Gas Chromatography-Mass Spectrometry (GC-MS) or Gas Chromatography-Ion Mobility Spectrometry (GC-IMS). In this work, we propose a modification (named psalsa) to the asymmetry weights of the original ALS method in order to better reject large peaks above the baseline. Our method will be compared to several versions of the ALS algorithm using synthetic and real GC signals. Results show that our proposal improves previous versions being more robust to parameter variations and providing more accurate peak areas.

Keywords: Gas chromatography, Instruments, Radioactivity measurement, Signal processing, Analytical instrument, Analytical Instrumentation, Asymmetric least squares, Baseline estimation, Baseline removal, Gas chromatography-mass spectrometries (GC-MS), Instrumental techniques, Noise levels, Iterative methods

Fernandez, L., Marco, S., (2014). Calibration transfer between e-noses Signal Processing and Communications Applications Conference (SIU) Signal Processing and Communications Applications Conference (SIU), 2014 22nd , IEEE (Trabzon, Turkey) , 650-653

Electronic nose is an instrument which is composed of gas sensor array and pattern recognition unit. It is generally used for classifying, identifying or quantifying the odors or volatile organic components for these commonly used devices, calibration transfer is an important issue because of differences in each instrument, sensor drift, changes in environmental conditions or background changes. Calibration transfer is a transfer of model between different instruments which have different conditions. In this study, calibration transfer is applied to the e-noses which have different temperature conditions. Also the results of the direct standardization, piecewise direct standardization and orthogonal signal correction which are different calibration methods were compared. The results of the piecewise direct standardization method are more successful than the other methods for the dataset which is used in this study.

Keywords: Calibration, Conferences, Electronic noses, Ethanol, Instruments, Signal processing, Standardization

Colomer-Farrarons, Jordi, Miribel-Català, Pere LI., Rodríguez-Villarreal, A. Ivón, Samitier, Josep, (2011). Portable bio-devices: Design of electrochemical instruments from miniaturized to implantable devices New perspectives in biosensors technology and applications (ed. Andrea Serra, Pier), InTech (Rijeka, Croatia) Biomedical Engineering, 373-400

A biosensor is a detecting device that combines a transducer with a biologically sensitive and selective component. Biosensors can measure compounds present in the environment, chemical processes, food and human body at low cost if compared with traditional analytical techniques. This book covers a wide range of aspects and issues related to biosensor technology, bringing together researchers from 12 different countries. The book consists of 20 chapters written by 69 authors and divided in three sections: Biosensors Technology and Materials, Biosensors for Health and Biosensors for Environment and Biosecurity.

Keywords: Bio-Devices, Electrochemical Instruments, Miniaturized Devices, Nanobiosensor

Colomer-Farrarons, J., Miribel-Catala, P. L., Samitier, J., Arundell, M., Rodriguez, I., (2009). Design of a miniaturized electrochemical instrument for in-situ O/sub 2/ monitoring Sensors and Signal Conditioning VLSI Circuits and Systems IV , SPIE (Desdren, Germany) 7363, 73630A

The authors are working toward the design of a device for the detection of oxygen, following a discrete and an integrated instrumentation implementation. The discrete electronics are also used for preliminary analysis, to confirm the validity of the conception of system, and its set-up would be used in the characterization of the integrated device, waiting for the chip fabrication. This paper presents the design of a small and portable potentiostat integrated with electrodes, which is cheap and miniaturized, which can be applied for on-site measurements for the simultaneous detection of O/sub 2/ and temperature in water systems. As a first approach a discrete PCB has been designed based on commercial discrete electronics and specific oxygen sensors. Dissolved oxygen concentration (DO) is an important index of water quality and the ability to measure the oxygen concentration and temperature at different positions and depths would be an important attribute to environmental analysis. Especially, the objective is that the sensor and the electronics can be integrated in a single encapsulated device able to be submerged in environmental water systems and be able to make multiple measurements. For our proposed application a small and portable device is developed, where electronics and sensors are miniaturized and placed in close proximity to each other. This system would be based on the sensors and electronics, forming one module, and connected to a portable notebook to save and analyze the measurements on-line. The key electronics is defined by the potentiostat amplifier, used to fix the voltage between the working (WE) and reference (RE) electrodes following an input voltage (Vin). Vin is a triangular signal, programmed by a LabView/sup c / interface, which is also used to represent the CV transfers. To obtain a smaller and compact solution the potentiostat amplifier has also been integrated defining a full custom ASIC amplifier, which is in progress, looking for a point-of-care device. These circuits have been designed with a 0.13 mu m technology from ST Microelectronics through the CMP-TIMA service.

Keywords: Amplifiers, Application specific integrated circuits, Chemical sensors, Electrodes, Portable instruments, Temperature measurement, Water sources