Abstract: The invention is related to the field of measurement electronics and related to the measurement of complex transfer functions (e.g. of impedance), especially in the presence of large disturbances and for measuring of small changes of the characteristics of the object under test. The goals of the proposed invention are achieved by detuning of the excitation and reference signals, e.g. by adding incremental phase-shift to the excitation signal to generate the reference signal.

Abstract: The invention belongs to the field of medical technology and relates to wearable electrical devices and a method for using the device to measure and monitor the patient's vital signs during the postoperative period in a hospital. The device enables more accurate measurement of the electrical bioimpedance of the patient's tissues, primarily arteries and other organs, which in turn provides an opportunity to determine the vital signs, such as the volume, frequency and nature of the heart beating and breathing, indicating whether the patient's health condition is improving or deteriorating towards the life-threatening direction. The device is distinguished by the methodology for creating and deploying a system of active electrodes specific to the measurement site of the body, and by the means for generating, forming and processing the electrical current and voltage signals necessary for measuring the electrical bioimpedance including the methods for applying the technology.

Abstract: A wearable bio-electromagnetic sensor comprises an electronic unit containing a means for generating electrical current, and an electromagnetic interface for transforming the generated electrical current into an electromagnetic field applied to a vascularized body tissue. Next, the wearable bio-electromagnetic sensor contains a means for analog signal processing an electrical response of cardiopulmonary system to the applied electromagnetic field. After analog processing of said electrical response, a digital post-processing of digitized electrical response takes place in a means for digital signal processing, embedded into said electronic unit of the wearable bio-electromagnetic sensor. As a result of analog and digital signal processing, an information is extracted, which makes possible medical diagnosing of both, pulmonary and cardiovascular system, separately or simultaneously.

Abstract: Microfluidic method and device that can be used for sensing and measurement of properties of liquids, gases, solutions, and particles is proposed, wherein the measurable liquid or gas (with or without particles) flow in at least one channel through a measurement chamber (cell) formed between at least two isolated electrodes is used for electrical impedance measurement. The proposed solution is characterized in that the cross-section of at least one pair of similar spatial electrodes decreases smoothly towards the tiny measurement chamber (cell) in order to increase the sensitivity and accuracy of the measurement. Typically, a device with multiple similar channels is advantageous to use for comparative measurement and differential measurement schemes.

Abstract: The invention is related to the field of measurement electronics and related to the measurement of complex transfer functions (e.g. of impedance), especially in the presence of large disturbances and for measuring of small changes of the characteristics of the object under test. The goals of the proposed invention are achieved by detuning of the excitation and reference signals, e.g. by adding incremental phase-shift to the excitation signal to generate the reference signal.

Abstract: Microfluidic method and device that can be used for sensing and measurement of properties of liquids, gases, solutions, and particles is proposed, wherein the measurable liquid or gas (with or without particles) flow in at least one channel through a measurement chamber (cell) formed between at least two isolated electrodes is used for electrical impedance measurement. The proposed solution is characterized in that the cross-section of at least one pair of similar spatial electrodes decreases smoothly towards the tiny measurement chamber (cell) in order to increase the sensitivity and accuracy of the measurement. Typically, a device with multiple similar channels is advantageous to use for comparative measurement and differential measurement schemes.

Abstract: A method and device for high speed broadband testing of systems and substances using a binary, spectrally sparse sequence (SSS) as a periodic excitation waveform. The sequences with controllable frequency and magnitude spectra content are designed by component manipulation method or by edge manipulation method. The excitation waveform is typically pre-calculated, and kept in waveform memory, from where it is shifted out into digital to physical quantity converter (DQC). The sparse spectrum of the SSS makes it easy to create plenty of uncorrelated frequency sets with adjacent, but sufficiently different frequencies to form multi-path test systems, where all the paths can be measured simultaneously. The response of the sample under test (SUT) is sampled and the complex transfer function is calculated directly or indirectly via Impulse Response by Discrete Fourier Transform technique and its derivatives. The sequence bit interval and sampling interval have a predetermined ratio.

Abstract: Method and device for impedance analyzer with binary excitation with improved accuracy, where the non-idealities of the sampling and preprocessing of the response signal (including aliasing effects) are taken into account by using of the overall system model with equivalent circuit diagrams of the analyzed object and the model of the preliminary analysis of the response signal. The analysis result is the equivalent circuit diagram with component values with the best match of the overall model analysis and of the preliminary analyze of the response signal. Further, the analysis result can be the impedance frequency characteristic or the classifier of the analyzed object. It could be reasonable to use the pre-calculated function (e.g. in the form of the look-up-table) for matching the results of the over-all model against the preliminary analyzed results of the response signal.

Abstract: A method for multichannel multifrequency analysis of an object, applying a set of excitation signals to the object and sampling the response signal from the object, using uniform and non-uniform undersampling. Non-uniform sampling of the response signal is performed, i.e., the sampling is performed for two or more different frequencies in one observation time slot. Also, uniform sampling of the response signal is performed, i.e., the sampling of a signal, corresponding to one frequency, is performed for two or more channels within one observation time slot and then sampling the same signal for another frequency for two or more channels within the next observation time slot.

Abstract: Method and device for impedance analyzer with binary excitation with improved accuracy, where the non-idealities of the sampling and preprocessing of the response signal (including aliasing effects) are taken into account by using of the overall system model with equivalent circuit diagrams of the analyzed object and the model of the preliminary analysis of the response signal. The analysis result is the equivalent circuit diagram with component values with the best match of the overall model analysis and of the preliminary analyze of the response signal. Further, the analysis result can be the impedance frequency characteristic or the classifier of the analyzed object. It could be reasonable to use the pre-calculated function (e.g. in the form of the look-up-table) for matching the results of the over-all model against the preliminary analyzed results of the response signal.

Abstract: A method for multichannel multifrequency analysis of an object, applying a set of excitation signals to the object and sampling the response signal from the object, using uniform and non-uniform undersampling. Non-uniform sampling of the response signal is performed, i.e., the sampling is performed for two or more different frequencies in one observation time slot. Also, uniform sampling of the response signal is performed, i.e., the sampling of a signal, corresponding to one frequency, is performed for two or more channels within one observation time slot and then sampling the same signal for another frequency for two or more channels within the next observation time slot.

Abstract: A method for multichannel multifrequency analysis of an object, applying a set of excitation signals to the object and sampling the response signal from the object, using uniform and non-uniform undersampling. Non-uniform sampling of the response signal is performed, i.e., the sampling is performed for two or more different frequencies in one observation time slot. Also, uniform sampling of the response signal is performed, i.e., the sampling of a signal, corresponding to one frequency, is performed for two or more channels within one observation time slot and then sampling the same signal for another frequency for two or more channels within the next observation time slot.

Abstract: A method and device for high speed broadband testing of systems and substances using a binary, spectrally sparse sequence (SSS) as a periodic excitation waveform. The sequences with controllable frequency and magnitude spectra content are designed by component manipulation method or by edge manipulation method. The excitation waveform is typically pre-calculated, and kept in waveform memory, from where it is shifted out into digital to physical quantity converter (DQC). The sparse spectrum of the SSS makes it easy to create plenty of uncorrelated frequency sets with adjacent, but sufficiently different frequencies to form multi-path test systems, where all the paths can be measured simultaneously. The response of the sample under test (SUT) is sampled and the complex transfer function is calculated directly or indirectly via Impulse Response by Discrete Fourier Transform technique and its derivatives. The sequence bit interval and sampling interval have a predetermined ratio.

Abstract: A method is provided for measuring a frequency response of an object, the method involving: generating an excitation signal having relatively fast changing frequency, defined by a time-domain function; generating at least one reference signal, having a waveform corresponding to the excitation signal; introducing the excitation signal into the object, receiving a response signal from the object; analyzing said response signal in a signal analyzer by correlating the response signal with at least one reference signal during a relatively short sliding time-domain window.

Abstract: In one method, one or more excitation signals with the same or different frequencies are applied to a biological object such as a tissue, simultaneously or consequently. Response signals are then cross-correlated with delayed excitation signals. Cross-correlation products are then auto-correlated. Cross-correlation products correspond to conditions of the tissue and auto-correlation product corresponds to changes in the conditions. Measuring electrical characteristics at low, intermediate and high frequency is also disclosed. At low frequency, the current flows mostly through the extracellular liquid of tissue. At high frequency, the current passes through the cell membranes freely enough to dominate the overall impedance. At both frequencies, the delay is less than 1/30 of the period of the respective signal. The intermediate frequency between the low frequency and the high frequency carries information about quick changes in the condition of the tissue.

Abstract: A method and device are provided for fast impedance measurement of a biological object having dynamically varying in time parameters, wherein a titlet shaped pulse is introduced into the object and a voltage response signal is measured and analyzed by a processing unit for estimating the impedance of the object. The titlet pulse has a start frequency substantially in one end of the frequency range of interest and a stop frequency substantially in the other end of the frequency range of interest and a duration of the titlet pulse is one cycle or less.

Abstract: A method for impedance measurements, using synchronous detecting and modified rectangular signals. The method comprises introducing a first modified rectangular signal into a bioobject, receiving a response signal from said bioobject, introducing said response signal and a second modified rectangular signal into a synchronous detector, whereas either one or both rectangular signals are modified to remove particular higher harmonics from the signal. In one embodiment, either one or both the first and the second modified rectangular signals are generated by summing at least two modified rectangular signals, wherein at least one of such rectangular signals have a zero amplitude segment introduced between rectangular half periods.

Abstract: A method for multichannel multifrequency analysis of an object, applying a set of excitation signals to the object and sampling the response signal from the object, using uniform and non-uniform undersampling. Non-uniform sampling of the response signal is performed, i.e., the sampling is performed for two or more different frequencies in one observation time slot. Also, uniform sampling of the response signal is performed, i.e., the sampling of a signal, corresponding to one frequency, is performed for two or more channels within one observation time slot and then sampling the same signal for another frequency for two or more channels within the next observation time slot.

Abstract: A method of measuring of an electrical bio-impedance, the method being characterized in that a symmetrical bipolar pulse-form periodical excitation signal (electrical current or voltage) is applied to the input (11) of the bio-object (1), a corresponding reaction of the bio-object to the mentioned excitation signal is measured from the output (12), which is connected to the input (201) of the synchronous detector (200). A symmetrical bipolar pulse-form periodical signal is also applied to the reference input (202) of the synchronous detector (200), whereby both pulse-form signals are shortened by the predetermined time interval in each half period of the signal, said time intervals being different for the excitation and reference signals. The proposed method ensures an increased accuracy of the impedance analysis by decreasing the influence of the higher harmonics in the spectra of the excitation and reference signals of the synchronous detectors to the measurement result.

Abstract: A device for monitoring cardiac pacing rate having a measuring unit for receiving an electrical signal representing the patient's cardiac demand, and a computing unit for determining the myocardial energy balance by calculating energy consumed by the myocardium for both an external dynamic work for pumping blood into a vascular system, and an internal static work of the myocardium. Volume and time based measurements are used, and in one embodiment, volumes are estimated and volume ratios are calculated from volume estimates. In another embodiment, volumes are estimated from bioimpedance measurements. A further aspect is a rate adaptive pacemaker, wherein the maximum pacing rate is determined from the myocardial energy balance such that the energy supplied to the myocardium approximately equals the energy consumed by the myocardium for both an external dynamic work for pumping blood into a vascular system and an internal static work of the myocardium.