65 results about "Electrical impedance spectroscopy" patented technology

The use of electrical impedance spectroscopy to adjust calibration settings in an in vivo monitoring system, such as an in vivo continuous glucose monitoring sensor. The adjustments can compensate for the condition of the sensor membrane in vivo.

Methods and apparatuses for determining surface wetting of a rock material with changing well fluids. In general, the methods according to the invention include measuring electrical impedance spectroscopy (“EIS”) for a system simulating downhole conditions for the wetting of a surface. Methods and apparatuses for making EIS measurements model double-layer capacitance at a downhole surface in a well, from which the nature and quantification of the wetting of the surface can be inferred.

The invention discloses a micro-flow control chip for cell tissue culture and real-time monitoring and a use method thereof. The chip comprises a glass substrate layer and a PDMS micro-flow channel layer positioned on the glass substrate layer; the glass substrate layer comprises a glass substrate and a plurality of pairs of microelectrodes arranged on the glass substrate layer; the PDMS micro-flow channel layer comprises a plurality of independent micro-fluidic channels; the microelectrodes on the glass substrate are corresponding to the micro-flow channels on the PDMS micro-flow channel layer one by one; the microelectrodes are electrically connected with an external circuit. The use method comprises the steps of cell capture, cell tissue culture, electrical impedance spectroscopy detection and tissue release. The chip disclosed by the invention is processed by a transparent substrate, microscopic imaging can be taken as a supplementary means of the electrical impedance spectroscopydetection, and the dynamic growth and the physiological behavior of cell tissues and other biological processes are subjected to observation and in-situ analysis. The micro-flow control chip can be used in the fields of biological research, drug screening and the like of cells or tissues.

The invention relates to a method and device which achieves skin moisture measurement with the help of bioelectrical impedance spectroscopy, in particular to a method and device for the skin moisture measurement. According to the method and device for the skin moisture measurement, electrical impedance values of the skin on multiple frequency points are measured through electrodes contacted with the skin of the human body, measurement results are converted into a complex impedance spectroscopy curve graph, and the complex impedance spectroscopy curve graph is displayed on a display screen of an instrument. According to the smooth condition of an impedance spectroscopy curve, kernel parameters are given out, and corresponding skin moisture content is calculated according to the kernel parameters. The method can simultaneously provide the electrical impedance spectroscopy curve and the skin moisture content obtained through calculation for users. According to the method and device for the skin moisture measurement, the measurement range of the skin moisture content is made to be expanded to the condition that the skin is quite dry, and given results are more visual and more dependable.

Methods and apparatuses for determining surface wetting of a metallic material with changing well fluids. In general, the methods according to the invention include measuring electrical impedance spectroscopy (“EIS”) for a system simulating downhole conditions for the wetting of a surface. Methods and apparatuses for making EIS measurements model double-layer capacitance at a downhole surface in a well, from which the nature and quantification of the wetting of the surface can be inferred.

The application discloses an alternating-current impedance spectrum acquisition method applied to a BMS system of a battery. The BMS system comprises an equalization switch. The alternating-current impedance spectrum acquisition method comprises the steps that: when the BMS system is in an equalization on state, the switching frequency of the equalization switch is sequentially adjusted to a plurality of preset frequency values, so that alternating-current impedance test signals corresponding to the preset frequency values are provided for the battery; an alternating current impedance of the battery under each preset frequency value is obtained; and an alternating-current impedance spectrum of the battery is obtained based on all alternating-current impedances. According to the application, when the BMS system of the battery enables the equalization function, the alternating-current impedance test signal is provided for the battery by adjusting the switching frequency of the equalization switch in the equalization circuit, so that the online measurement of the alternating-current impedance spectrum is realized without any additionally designed alternating-current impedance test equipment and thus the hardware cost is saved. In addition, the invention also discloses an alternating-current impedance spectrum acquisition device, electronic equipment and a computer readable storagemedium, which have the above beneficial effects.

A multi-frequency inductive sensing system can be used for spectrographic material analysis of a conductive target material (such as tissue) based on electrical impedance spectroscopy. An inductive sensor can be driven with an excitation current at multiple sensor excitation frequencies (ω) to project a time-varying magnetic field into a sensing area on the surface of the target material, inducing eddy currents within the target material. The inductive sensor can be characterized by a sensor impedance Z(ω) as a function of the sensor excitation frequency (ω), and the resulting induced eddy currents. Multiple sensor impedance Zs(ω) measurements, at the multiple sensor excitation frequencies (ω), can be determined, which represent electromagnetic properties of the target material (such as permittivity ε, permeability μ, and resistivity ρ), based on the induced eddy currents. The multiple sensor excitation frequencies (ω), and corresponding multiple sensor impedance Zs(ω) measurements, can be selected for particular target penetration depths.

The invention belongs to the field of electrical impedance tomography, and particularly relates to a dynamic multi-frequency electrical impedance tomography method based on the impedance frequency spectrum constraint. The method includes the steps that 1, limited surface element dividing is carried out in an imaging region, the variety number of tissue in the imaging region and the frequency spectrum of each kind of tissue are determined, and a relation model of the volume fraction and the boundary voltage is established; 2, the boundary of the imaging region is excited through exciting currents at different frequencies, and boundary voltage data at different moments at each frequency is measured; 3, an inverse problem objective function is established according to the relation of the volume fraction change and the boundary voltage pressure obtained in the step 1 and solved, and the change value of the volume fraction in the imaging region is obtained; 4, the volume fraction change isconverted into the impedance change, the impedance change is shown in the imaging region through color levels, and an impedance change image is obtained. A novel scheme for relieving the inverse problem morbidity is provided on the aspect of increasing the observation data size, and then the space resolution and the anti-noise capacity of the reconstructed image are improved.

A sensor uses microneedle electrodes and multi-frequency electrical impedance spectroscopy to monitor plant water status in real time. The microneedle can be between 10 and 1000 microns in length, enabling precise placement in a variety of plant tissues. The impedance behavior can distinguish electrical properties and physiological functions of different plant tissue types. Therefore, impedance measurements can be used to monitor water stress to prevent irreversible damage to a plant and to enable improvement of plant biomass or fruit yield.

The invention provides a method for detecting lysozyme. The method comprises the following steps of dispensing a metal organic skeleton solution to the surface of a gold electrode, carrying out incubating, washing and nitrogen drying; dispensing a lysozyme aptamer solution to the surface of the gold electrode, carrying out incubating, washing and nitrogen drying and carrying out first electrochemical impedance spectroscopy detection; washing the gold electrode after first electrochemical impedance spectroscopy detection, carrying out nitrogen drying, dispensing the solution to a to-be-detected sample, carrying out incubating, washing and nitrogen drying, and carrying out second electrochemical impedance spectroscopy detection; subtracting electron transfer resistance in a first electrical impedance spectroscopy from the electron transfer resistance in a impedance spectroscopy of the to-be-detected sample to obtain an electron transfer resistance difference and comparing with a default standard curve to obtain the concentration of the lysozyme. According to the embodiment of the invention, the adopted detection method is simple in operation, marking is not needed, the flexibility is relatively high, the detection limit can reach 2.0*10<-11>mol/L and the linear range is 1.0*10<-7>mol/L to 1.0*10<-11>mol/L.

The invention provides a method and a device for detecting impedance spectrum of easily-made drug chemicals. The method comprises the following steps: generating sine waves of different frequencies through the control of a single chip microcomputer by virtue of a digital frequency synthesis technique; generating corresponding constant potentials from sine waves of the different frequencies by virtue of a constant potential rectifier, and loading the constant potentials to a counter electrode of a detection electrode; generating an alternating electric field in measured liquid by virtue of the detection electrode, so as to form current; feeding the current back to the constant potential rectifier by virtue of a working electrode of the detection electrode, amplifying the current, and carrying out impedance and phase detection; inputting detected signals into the single chip microcomputer, so as to finish the data collection of a sample; and making comparison between the impedance and phase data of the measured sample under different frequencies and a standard atlas database, so as to obtain a detection result. A convenient and rapid method is provided for the detection of the easily-made drug chemicals. The method has the beneficial effects that the implementation is convenient, the requirements on a tester is low, no reagent is used, the device is small in volume, light and simple to operate, the tracking is realized, and specialist data is updated in real time; and the method has very good adaptability to novel medicines.

A system and method for beamforming in soft-field tomography are provided. One soft-field tomography system includes a plurality of transducers configured for positioning proximate a surface of an object and one or more excitation drivers coupled to the plurality of transducers and configured to generate excitation signals for the plurality of transducers. The excitation signals include at least one frequency component. The soft-field tomography system further includes one or more response detectors coupled to the plurality of transducers and configured to measure a response of the object at the plurality of transducers to the excitation applied by the plurality of transducers based on the excitation signals. The soft-field tomography system also includes a soft-field reconstruction module configured to reconstruct a property distribution based on the excitation signals and the measured response using an Electrical Impedance Spectroscopy (EIS) beamformer.

Methods and apparatuses for determining surface wetting of metallic materials at downhole wellbore condition with fixed or changing well fluids are disclosed. In general, the methods according to the disclosure include carrying out an electrical impedance spectroscopy (“EIS”) for a system simulating downhole conditions for the wetting of a surface by simultaneously dynamically moving electrodes exposed to the well fluid while measuring the changes in electrical characteristics between the electrodes.

The invention discloses a micro-fluidic chip for monitoring nematode movement behaviors and physiological characteristics. A fluid inlet, a culture cavity array, a sampling inspection channel, an electrical impedance tomography detection cavity, an electrical impedance spectroscopy detection cavity and a fluid outlet are connected in sequence; a casual inspection control valve is arranged on a casual inspection channel and used for controlling a channel to be opened or closed; a detection control valve is arranged between the electrical impedance tomography detection cavity and the electricalimpedance spectroscopy detection cavity and used for controlling the channel to be opened or closed; the electrical impedance tomography electrode array is connected with the electrical impedance tomography detection cavity; and the electrical impedance spectroscopy detection electrode array is connected with the electrical impedance spectroscopy detection cavity. By the adoption of the technicalscheme, integration of the culture cavity, the electrical impedance tomography detection cavity and the electrical impedance spectroscopy detection cavity can be achieved, the functions of nematode culture, movement behavior and physiological structure detection and the like are achieved, and high-automation and high-efficiency culture and detection can be achieved in cooperation with the controlvalve.

The present invention provides an electrical impedance method for measuring soluble sugar content in catalpa bungei stem leaf. The method comprises the steps of: detecting an electrical impedance spectroscopy of a catalpa bungei stem leaf sample to be tested; according to the electrical impedance spectroscopy of the sample to be tested, determining an appropriate equivalent circuit; according to the equivalent circuit, fitting the data of the electrical impedance spectroscopy of the sample to be tested to obtain electrical impedance parameters of the sample to be tested; and according to a regression model of the predetermined electrical impedance parameters of the catalpa bungei stem leaf with soluble sugar content, and the electrical impedance parameters of the sample to be tested, acquiring the soluble sugar content of the catalpa bungei stem leaf. The method provided by the invention establishes a regression model of the electrical impedance parameters and soluble sugar content of the catalpa bungei stem leaf, thus calculating the soluble sugar content of the catalpa bungei stem leaf based on the measured impedance parameters. The method can realize fast real-time diagnosis of the soluble sugar content and can obtain the cold resistance of the catalpa bungei stem leaf through the Logistic equation.

The invention discloses a method and a device for determining high-frequency oscillation reasons of a wind power plant, and the method comprises the steps: building a sweep frequency simulation model corresponding to each piece of oscillation equipment according to the obtained actual equipment parameters of each piece of oscillation equipment in the wind power plant, and determining the sweep frequency impedance characteristics corresponding to each piece of oscillation equipment in a small signal analysis mode; determining an electrical node network according to the obtained topological structure diagram of the wind power plant; according to a preset equipment combination mode, the electrical node network and the sweep frequency impedance characteristic, determining an impedance spectrogram corresponding to each piece of oscillation equipment in the preset equipment combination mode by utilizing a node impedance aggregation calculation mode; and determining the reason of high-frequency oscillation in the wind farm according to the impedance spectrogram. According to the method, the internal equipment of the wind power plant is subjected to refined modeling, the whole wind power plant and the internal equipment individuals are analyzed, high-frequency oscillation determination under the condition of multiple equipment and multiple factors is completed in a refined mode, and the reason of high-frequency oscillation of the internal equipment of the wind power plant is more comprehensively positioned.

An apparatus for use in determining a plurality of characteristics of a multiphase flow within a pipe is disclosed. In one exemplary embodiment, the apparatus comprises first and second constrictions, a sheltered zone between the first and second constrictions, a sensing device coupled to an interior wall of the pipe, and a sheltered device coupled to the interior wall of the pipe and located within the sheltered zone. A first characteristic of the plurality of characteristics is determinable from data generated by the sensing device. A second characteristic of the plurality of characteristics is determinable from data generated by the sheltered device. In one exemplary embodiment, the first characteristic is a gas fraction, and the sensing device is a plurality of pressure sensors. In another exemplary embodiment, the second characteristic is a phase fraction, and the sheltered device is a plurality of electrical impedance spectroscopy (EIS) electrodes.

The invention discloses an acoustic evaluation method and experimental device for a harp resonance box based on impedance technology, and is characterized in that: the experimental device includes an impedance analyzer, a harp resonance box, a first piezoelectric sensor, and a second piezoelectric sensor , the third piezoelectric sensor, the fourth piezoelectric sensor, a computer and its software processing system, the acoustic evaluation method and experimental device of the present invention, without the need for the player to play the harp, directly use the impedance analyzer to test the harp resonance box in the middle range. , high-pitched zone 1, high-pitched zone 2, and super high-pitched zone are scanned to test the impedance spectrum of the harp resonance box within the scanning frequency range, and then judge the pros and cons of the harp resonance box according to the impedance spectrum of the harp resonance box . The invention has simple structure and reasonable design, overcomes the artificial factors in evaluating the timbre of the harp in the traditional method, objectively evaluates the quality of the timbre of the harp resonance box, and provides a brand-new harp evaluation method for harp manufacturers.