Correction of the influence of baseline artefacts and electrode polarisation on dielectric spectra

Yardley, John Edmund; Todd, Robert W.; Nicholson, David; Barrett, J. D.; Kell, Douglas B.; Davey, Christopher L.

doi:10.1016/s0302-4598(99)00069-0

Cited by 17 publications

(15 citation statements)

References 23 publications

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“…Multivariate analysis can be used to model biomass concentration and cell size as two separate variables by exploiting the distinctive shapes of the capacitance spectra. A parameter of particular importance is the position the characteristic frequency, which should ideally be indicative of the morphology and average size of cells in the system [18,19,42]. Smaller cells are more readily polarized so the characteristic frequency of suspensions containing these cells will be greater than that of a suspension of larger cells (Fig.…”

Section: Multivariate Modeling Of Scanning Dielectric Signalsmentioning

confidence: 99%

Cole–Cole, linear and multivariate modeling of capacitance data for on-line monitoring of biomass

Dabros

Dennewald

Currie

et al. 2008

Bioprocess Biosyst Eng

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This work evaluates three techniques of calibrating capacitance (dielectric) spectrometers used for on-line monitoring of biomass: modeling of cell properties using the theoretical Cole-Cole equation, linear regression of dual-frequency capacitance measurements on biomass concentration, and multivariate (PLS) modeling of scanning dielectric spectra. The performance and robustness of each technique is assessed during a sequence of validation batches in two experimental settings of differing signal noise. In more noisy conditions, the Cole-Cole model had significantly higher biomass concentration prediction errors than the linear and multivariate models. The PLS model was the most robust in handling signal noise. In less noisy conditions, the three models performed similarly. Estimates of the mean cell size were done additionally using the Cole-Cole and PLS models, the latter technique giving more satisfactory results.

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Section: Multivariate Modeling Of Scanning Dielectric Signalsmentioning

confidence: 99%

Cole–Cole, linear and multivariate modeling of capacitance data for on-line monitoring of biomass

Dabros

Dennewald

Currie

et al. 2008

Bioprocess Biosyst Eng

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“…Electrical impedance tomography (EIT) has been proposed as a possible technology to detect intracerebral hemorrhage (ICH) in an animal model [9] and impedance spectroscopy has been suggested as a method to detect stroke related brain asymmetries in men [10]. However, EIT requires the injection of current through an electrode-skull contact that could reduce the detection precision [11]. Besides, the current is difficult to pass the super-high resistivity skull and may therefore severely reduce the imaging quality [11].…”

Section: Introductionmentioning

confidence: 99%

Magnetic inductive phase shift: a new method to differentiate hemorrhagic stroke from ischemic stroke on rabbit

Yan

Jin

et al. 2017

BioMed Eng OnLine

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BackgroundThe major therapy for ischemic stroke is thrombolytic treatment, but severe consequences occur when this method is used to treat hemorrhagic stroke. Currently, computed tomography and magnetic resonance imaging are used to differentiate between two types of stroke, but these two methods are ineffective for pre-hospital care.MethodsWe developed a new brain diagnostic device for rabbits based on electromagnetic induction to non-invasively differentiate two types of stroke. The device includes two coils and a phase difference measurement system that detects the magnetic inductive phase shift (MIPS) value to reflect the tissue’s condition. The hemorrhage model was established through the injection of autologous blood into the internal capsule of a rabbit’s brain. Ischemia was induced in the brain of a rabbit by bilateral carotid artery occlusion. Two types of animal models were measured with our device.ResultsThe MIPS value gradually decreased with increasing injected blood and increased with ischemia time. The MIPS changes induced by the two types of strokes were exact opposites, and the absolute values of MIPS variation in the hemorrhagic and the ischemic groups were significantly larger than those of the normal control group (P < 0.05).ConclusionsThe tested technique can differentiate ischemic stroke from hemorrhagic stroke on rabbit brain in a non-invasive, continuous, and bulk monitoring manner by using a simple and inexpensive apparatus.

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“…This procedure was repeated approximately once per week. An improved long-term electric stability was obtained by slight modifications of the treatments described by Woodward et al [23] and Yardley et al [28]: The electrodes were additionally washed with chloroform, sonicated for 20 min in a detergent solution (0.5 % Triton X-100 in water), treated with CaCl 2 (0.5 M in water) in a ultrasonic bath (Bachhofer, Reutlingen), and finally rinsed with de-ionized water (<2 μS). This treatment resulted in amplitude deviations ≤ 5% over an experimental session of up to 2 h. If electrodes were not used for DC measurements, but for NLDS, they were additionally coated with a thin polymer film in order to improve noise reduction and stability [24].…”

Section: Methodsmentioning

confidence: 99%

Untitled

Pazur

2004

BioMag Res Technol

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Background: Previous reports indicate altered metabolism and enzyme kinetics for various organisms, as well as changes of neuronal functions and behaviour of higher animals, when they were exposed to specific combinations of weak static and alternating low frequency electromagnetic fields. Field strengths and frequencies, as well as properties of involved ions were related by a linear equation, known as the formula of ion cyclotron resonance (ICR, abbreviation mentioned first by Liboff). Under certain conditions already a aqueous solution of the amino acid and neurotransmitter glutamate shows this effect.

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Correction of the influence of baseline artefacts and electrode polarisation on dielectric spectra

Cited by 17 publications

References 23 publications

Cole–Cole, linear and multivariate modeling of capacitance data for on-line monitoring of biomass

Cole–Cole, linear and multivariate modeling of capacitance data for on-line monitoring of biomass

Magnetic inductive phase shift: a new method to differentiate hemorrhagic stroke from ischemic stroke on rabbit

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