Abstract: A method for determining cardiac impulse conduction, in particular three-dimensional cardiac impulse conduction, in a patient, comprising: generating an image recording of an area of the body of the patient capturing at least partially electrocardiogram electrodes arranged on the body of the patient by an imaging modality; determining positions of the electrocardiogram electrodes in a system of coordinates assigned to the imaging modality; recording of potential data of some of the electrocardiogram electrodes; and reconstructing cardiac impulse conduction depending on the determined positions of the electrocardiogram electrodes, the image recording and the recording of potential data of the electrocardiogram electrodes, wherein at least one image recording is generated substantially simultaneously with the recording of potential data of the electrocardiogram electrodes or is generated in the period between two recordings of potential data of the electrocardiogram electrodes.

Abstract: There are provided an electrocardiograph with an extended lead function and an extended lead ECG deriving method capable of easily deriving an ECG signal of an extended lead ECG by an arithmetic operation, based on ECG signals of a standard 12-lead ECG measured by a potential detector 10. An ECG memory 12 stores the ECG signals measured as the standard 12-lead ECG by the potential detector 10. An extended lead ECG calculator 16 calculates extended lead ECGs V7-V9 from the ECG signals stored in the ECG memory 12, using coefficients ? representing a relationship among leads. The extended lead ECGs V7-V9 calculated are displayed through an extended lead ECG waveform outputting device 18 on a display monitor 20.

Abstract: The invention relates to methods of differentiating between ventricular tachycardias (VTs) and supraventricular tachycardias (SVT) with the assistance of morphology detection, and signal processing devices implementing such methods.

Abstract: Cardiac sensing and/or stimulation devices and methods that adapt to implant location and positioning, and may employ automated vector selection from multiple electrodes. Devices include a housing having a first face opposing a second face, and an edge extending around the perimeter. A pulse generator and controller are coupled to three or more electrodes. Electrode arrangement facilitates selection of the particular electrodes that sense cardiac activity irrespective of one or more of positioning of the device, rotation of the housing, and which of the first and second faces of the housing is orientated toward the patient's skin. A first vector may be selected that provides for sensing cardiac activity, and a second vector may sense skeletal muscle activity. The vectors may be selected based on amplitude or signal-to-noise ratio exceeding a predetermined threshold. Methods may involve delivering defibrillation or cardioversion energy and/or determining cardiac rhythm states using selected vectors.

Abstract: A method for determining the presence of atrial fibrillation includes obtaining data from at least three orthogonal leads indicative of electrical activity of a heart over multiple heart beats, averaging the data to obtain an average heart beat, generating, from the averaged data, an average heart beat vectorcardiogram (VCG) that is a function of voltage level, comparing, over a segment of the average heart beat, the average heart beat VCG with a threshold value, and indicating whether the average heart beat VCG exceeds or does not exceed the threshold value.

Abstract: The reconstruction of a surface electrocardiogram based upon an endocardial electrogram. This method includes: (a) acquisition (10) of a plurality of endocardial electrogram signals (EGM) through a plurality of endocardial leads defined based upon endocardial electrodes; (b) calculation (12), by combining the endocardial electrogram (EGM) signals acquired at step (a), of the corresponding endocardial vectogram (VGM); (c) angular resealing (14) of the orthonormalized mark of the endocardial vectogram (VGM) with that of the surface vectocardiogram (VCG); (d) estimation (16), based upon the endocardial vectogram (VGM) calculated at step (b), of a reconstructed surface vectocardiogram (VCGreconstructed), and (e) calculation (18) of the surface electrocardiogram (ECG) corresponding to said reconstructed surface vectocardiogram (VCGreconstructed).

Abstract: An apparatus in connection with a fitness exercise of a person, including means for processing multidimensional electrocardiographic data of the person, the multidimensional electrocardiographic data comprising at least two spatially separately measured electrocardiographic signal components, means for forming a vectorcardiographic measure on the basis of the multidimensional electrocardiographic data, and means for applying the vectorcardiographic measure in determination of a fitness exercise related parameter.

Abstract: Cardiac monitoring and/or stimulation methods and systems provide for monitoring, diagnosing, defibrillation and pacing therapies, or a combination of these capabilities, including cardiac systems incorporating or cooperating with neuro-stimulating devices, drug pumps, or other therapies. Embodiments of the present invention relate generally to implantable medical devices employing automated cardiac activation sequence monitoring and/or tracking for arrhythmia discrimination. Embodiments of the invention are directed to devices and methods involving sensing a plurality of composite cardiac signals using a plurality of implantable electrodes. A source separation is performed using the sensed plurality of composite cardiac signals and the separation produces one or more cardiac signal vectors associated with one or more cardiac activation sequences that is indicative of ischemia. A change of the one or more cardiac signal vectors is detected using the one or more cardiac signal vectors.

Abstract: Cardiac monitoring and/or stimulation methods and systems provide monitoring, defibrillation and/or pacing therapies. A signal processor receives a plurality of composite signals associated with a plurality of sources, separates a signal using a source separation algorithm, and identifies a cardiac signal using a selected vector. The signal processor may iteratively separate signals from the plurality of composite signals until the cardiac signal is identified. The selected vector may be updated if desired or necessary. A method of signal separation involves detecting a plurality of composite signals at a plurality of locations, separating a signal using source separation, and selecting a vector that provides a cardiac signal. The separation may include a principal component analysis and/or an independent component analysis.

Abstract: Cardiac monitoring and/or stimulation methods and systems provide for monitoring, diagnosing, defibrillation and pacing therapies, or a combination of these capabilities, including cardiac systems incorporating or cooperating with neuro-stimulating devices, drug pumps, or other therapies. Embodiments relate generally to implantable medical devices employing automated cardiac activation sequence monitoring and/or tracking for arrhythmia discrimination. Embodiments are directed to devices and methods involving sensing a plurality of composite cardiac signals using a plurality of implantable electrodes. A source separation is performed using the sensed plurality of composite cardiac signals and the separation produces one or more cardiac signal vectors associated with one or more cardiac activation sequences that is indicative of ischemia. A change of the one or more cardiac signal vectors is detected using the one or more cardiac signal vectors.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing cardiac signals from a plurality of electrodes forming a first sensing vector and a second sensing vector, and determining first heart rate estimates associated with cardiac signals sensed from the first sensing vector and cardiac signals sensed from the second sensing vector in response to a metric of heart rate associated with the sensed cardiac signals. Second heart rate estimates associated with the first sensing vector and with the second sensing vector are generated in response to the determined first heart rate estimates, and a determination is made as to whether both of the second heart rate estimates are greater than a predetermined heart rate threshold.

Abstract: A method comprising sensing at least one cardiac signal representative of cardiac activity of a subject using an implantable medical device (IMD), calculating, from the cardiac signal, a first dominant vector corresponding to a direction and magnitude of maximum signal power of an ST-T first segment of a cardiac cycle and a second dominant vector corresponding to a direction and magnitude of maximum signal power of a P-QRS second segment of a cardiac cycle, measuring a change in the first dominant vector, measuring a change in the second dominant vector, and subtracting the change in the second dominant vector from the measured change in the first dominant vector to form a difference.

Abstract: Cardiac monitoring and/or stimulation methods and systems provide monitoring, diagnosis, and defibrillation and/or pacing therapies. A signal processor receives a plurality of composite signals associated with a plurality of sources, performs a source separation, and produces one or more cardiac signal vectors associated with all or a portion of one or more cardiac activation sequences based on the source separation. A method of signal separation involves detecting a change in a characteristic of the cardiac signal vector relative to a baseline. One or more vectors and/or activation sequences may be selected, and information associated with the vectors and/or activation sequences may be stored and tracked.

Abstract: Systems and methods for characterizing aspects of an electrocardiogram signal are presented, wherein primary and secondary analysis schemas are utilized to determine the timing of the end of a signal wave, such as a descending Twave, with precision. In one embodiment, the primary analysis schema involves comparing voltage amplitudes within a given sampling window and the secondary analysis schema involves comparing the results of primary analysis for successive sampling windows. The system may comprise a processor or microcontroller embedded into a system such as an electrocardiogram hardware system, personal computer, electrophysiology system, or the like.

Abstract: Cardiac monitoring and/or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed to detect, monitor, track and/or trend ischemia using cardiac activation sequence information. Ischemia detection may involve sensing composite cardiac signals using implantable electrodes, and performing a signal separation that produces one or more cardiac activation signal vectors associated with one or more cardiac activation sequences. A change in the signal vector may be detected using subsequent separations. The change may be an elevation or depression of the ST segment of a cardiac cycle or other change indicative of myocardial ischemia, myocardial infarction, or other pathological change. The change may be used to predict, quantify, and/or qualify an event such as an arrhythmia, a myocardial infarction, or other pathologic change. Information associated with the vectors may be stored and used to track the vectors.

Abstract: Method and apparatus for monitoring a plurality of physiological factors contributing to physiological conditions of a heart, that determines a first impedance, corresponding to the plurality of physiological factors, across a plurality of vectors, and a second impedance, corresponding to the plurality of physiological factors, across the plurality of vectors subsequent to determining the first impedance.

Abstract: Cardiac monitoring and/or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed to detect, monitor, track and/or trend a patient's posture using cardiac activation sequence information. Devices and methods involve sensing a plurality of composite cardiac signals using a plurality of implantable electrodes. A source separation is performed using the composite cardiac signals, which produces one or more cardiac signal vectors associated with all or a portion of one or more cardiac activation sequences. A change in a patient's posture is detected using the cardiac signal vectors. Further embodiments involve sensing the plurality of composite cardiac signals during the patient's predominant cardiac rhythm before detecting the change in the patient's posture. Other embodiments involve discriminating between one of a postural related change and a cardiac rhythm related change using the cardiac signal vectors.

Abstract: Cardiac monitoring and/or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed to detect, monitor, track and/or trend ischemia using cardiac activation sequence information. Ischemia detection may involve sensing composite cardiac signals using implantable electrodes, and performing a signal separation that produces one or more cardiac activation signal vectors associated with one or more cardiac activation sequences. A change in the signal vector may be detected using subsequent separations. The change may be an elevation or depression of the ST segment of a cardiac cycle or other change indicative of myocardial ischemia, myocardial infarction, or other pathological change. The change may be used to predict, quantify, and/or qualify an event such as an arrhythmia, a myocardial infarction, or other pathologic change. Information associated with the vectors may be stored and used to track the vectors.

Abstract: Methods and devices configured for analyzing sensing vectors in an implantable cardiac stimulus system. In an illustrative example, a first sensing vector is analyzed to determine whether it is suitable, within given threshold conditions, for use in cardiac event detection and analysis. If so, the first sensing vector may be selected for detection and analysis. Otherwise, and in other examples, one or more additional sensing vectors are analyzed. A polynomial may be used during analysis to generate a metric indicating the suitability of the sensing vector for use in cardiac event detection and analysis. Additional illustrative examples include systems and devices adapted to perform at least these methods, including implantable medical devices, and/or programmers for implantable medical devices, and/or systems having both programmers and implantable medical devices that cooperatively analyze sensing vectors.

Abstract: Methods and systems may identify a vector or a vector configuration, such as a combination of electrodes, for monitoring ischemia. The method may include: selecting a first combination of sensors as a first candidate to be used for monitoring ischemia; detecting a shift in a ST segment of one of an electrocardiogram and a cardiac electrogram using the first candidate; selecting a second combination of sensors as a second candidate to be used for monitoring ischemia; detecting a shift in a ST segment of one of an electrocardiogram and a cardiac electrogram using the second candidate; comparing the ST shifts for the first and second candidates; and identifying one of the first and second candidates for monitoring ischemia based on the comparison. A multi-electrode implantable cardiac device may include a controller configured to effectuate such functions.

Abstract: A method of detecting a cardiac event that includes sensing cardiac signals from a plurality of electrodes, determining rates of change of the sensed cardiac signals, and determining a range of the sensed cardiac signals. The sensed cardiac signals are detected as being associated with the cardiac event in response to the determined rates of change and the determined range.

Abstract: A method of detecting a cardiac event in a medical device that includes determining a first characteristic in response to cardiac signals sensed along a first sensing vector over a predetermined sensing window and in response to cardiac signals sensed along a second sensing vector over the predetermined sensing window, determining a second characteristic in response to cardiac signals sensed along the first sensing vector over the predetermined sensing window and in response to cardiac signals sensed along the second sensing vector over the predetermined sensing window, and determining a third characteristic in response to cardiac signals sensed along the first sensing vector over the predetermined sensing window and in response to cardiac signals sensed along the second sensing vector over the predetermined sensing window.

Abstract: The analysis of ECG (electrocardiogram) data by exploiting computerized three-dimensional spatial presentation of the measured data using the vector concept. A three-dimensional presentation of the human heart may be correlated with waveforms specific for standard ECG or derived ECG signals based on the dipole approximation of the heart electrical activity. The three-dimensional heart model may be rotated, and the ECG signals are interactively linked to the model. Cardiac ischemia (inadequate blood supply) is detected by calculating an ECG ST-segment vector magnitude or an ST-T spatial angle change of a heart vector from the heart model and comparing these to respective predetermined ischemia criteria, using actual or virtual ECG lead sites.

Abstract: A medical device includes one or more sensors used to acquire a multi-dimensional signal. In one embodiment, principal component analysis is performed on the multi-dimensional signal to produce signal data. The principal component analysis results are used to cancel signal artifact in one embodiment. A medical device controller produces one of a therapy control and a diagnostic output in response to the signal data.

Abstract: An apparatus for measuring cardiac electrical activity of a patient includes: a malleable pad, a first electrocardiogram electrode, and a ground electrode. The pad includes: a right handle for grasping with the patient's right hand, the right handle including an electrocardiogram electrode; a left handle for grasping with the patient's left hand, the left handle also including an electrocardiogram electrode; and an electronic circuit configured for receiving electrical signals from the electrodes and also configured to invert the signals from the electrodes for transmission to a processor to produce a graphic recording of the differences in electrical potential between the electrodes. The pad also includes a multiplex cable for coupling the electronic circuit to leadwires attached to the electrocardiogram electrodes; and a port configured for coupling with the processor.

Abstract: A medical display for analyzing heart signals includes a cardiographic display which displays an electrocardiograph (ECG) heart signal segment of a patient having a magnitude and location in vector format within a single three-dimensional (3D) coordinate system (vectorcardiograph) sampled at incremental time intervals. The display communicates with a central processing unit (CPU) that implements an algorithm to permit a user to selectively and visually display a comparison of the patient ECG with at least one known display in vector format within a single three-dimensional (3D) coordinate system. The display also permits a user to selectively and visually convert and display an ECG heart signal segment into a color-coded projection of a time sequence, A method for analyzing heart signals includes implementing the algorithm to selectively and visually compare the ECG heart signal with at least one known display in vector format selected from the group.

Abstract: The invention relates to the analysis of ECG data by exploiting computerized three-dimensional spatial presentation of the measured data using the vector concept. A three-dimensional presentation of the human heart may be correlated with waveforms specific for standard ECG or derived ECG signals based on the dipole approximation of the heart electrical activity. The three-dimensional heart model may be rotated, and the ECG signals are interactively linked to the model. In the visualization process, different types of signal presentation may be used, including graphical presentation of the heart vector hodograph, graphical presentation of the signal waveform in an arbitrary chosen point on the heart, and graphical presentation of the map of equipotential lines on the heart in a chosen moment. Additional tools for analyzing ECG data are also provided which may be interactively used with the display tools.

Abstract: The invention relates to a method for transforming physiological data from the time domain to the frequency domain. The method includes the steps of: providing a plurality of digital data in the time domain; providing a microcomputer programmed to run a recursive Fourier transform estimation algorithm; calculating, for each newly received digital data in the time domain, an integer index using modulo(N) arithmetic based on a time the each newly received data was received; selecting a frequency vector from a plurality of N frequency vectors using the integer index; and updating the plurality of frequency coefficients according to a recursive equation including the selected frequency vector as an input variable. The invention also relates to an apparatus that performs a recursive Fourier transform estimation algorithm to convert data in the time domain to data in the frequency domain.

Abstract: A system and method for MR imaging is disclosed that includes an MRI system having a plurality of gradient coils positioned about a bore of a magnet to impress a polarizing magnetic field and an RF transceiver system and an RF switch controlled by a pulse module to transmit RF signals to an RF coil assembly to acquire MR images. A computer is included that is programed to generate a motion waveform from a physiological signal acquired from a subject to be imaged and compare a shape of the motion waveform to a shape of a reference motion waveform to identify points in the motion waveform corresponding to a periodic complex. The computer is also programed to trigger MR data acquisition from the subject upon identification of the periodic complex.

Abstract: A method of detecting a cardiac event in a medical device that includes sensing a cardiac signal from a plurality of electrodes, determining amplitudes of the sensed cardiac signal during a predetermined sensing window, determining a noise to signal ratio corresponding to the determined amplitudes, and determining the sensed cardiac signal during the predetermined sensing window is corrupted by noise in response to the determined noise to signal ratio being greater than a noise to signal ratio threshold.

Abstract: A method and system for atrial fibrillation analysis, characterization, and mapping is disclosed. A finite element model (FEM) representing a physical structure of a heart is generated. Electrogram data can be sensed at various locations in the heart using an electrophysiology catheter, and the electrogram data is mapped to the elements of the FEM. Function parameters, which measure some characteristics of AF arrhythmia, are then simultaneously calculated for all of the elements of the FEM based on the electrogram data mapped to the elements of the FEM. An artificial neural network (ANN) can be used to calculate the function parameters.

Abstract: Cardiac monitoring and/or stimulation methods and systems provide monitoring, defibrillation and/or pacing therapies. A signal processor receives a plurality of composite signals associated with a plurality of sources, separates a signal using a source separation algorithm, and identifies a cardiac signal using a selected vector. The signal processor may iteratively separate signals from the plurality of composite signals until the cardiac signal is identified. The selected vector may be updated if desired or necessary. A method of signal separation involves detecting a plurality of composite signals at a plurality of locations, separating a signal using source separation, and selecting a vector that provides a cardiac signal. The separation may include a principal component analysis and/or an independent component analysis.

Abstract: The invention determines the heart rate and respiration rate of a patient through the patient's extremities. Heart rate and respiration rate are determined via an energy spectrum, periodogram or histogram using a time series analysis. A patient can stand near the device and lean on it, or stand on a piezoelectric pad. A microcomputer provides calculations to determine heart and respiratory rates using signal processing and time series analysis of data.

Abstract: Approaches for estimating capture thresholds for alternate pacing vectors of multi-electrode pacing devices are described. Capture thresholds of at least one initial pacing vector is measured. The impedance of the initial pacing vector and at least one alternate pacing vector is measured. The initial and alternate pacing vectors have an electrode in common. The common electrode has the same polarity in both the initial and the alternate pacing vectors. The capture threshold for the alternate pacing vector may be estimated based on the measured capture threshold of the initial pacing vector, the measured the impedance of the initial pacing vector, and the measured impedance of the alternate pacing vector.

Abstract: A way of quantifying the shape of an ECG waveform is disclosed by detecting the JT segment using two Hidden Markov Models and calculating the analytic signal of the JT segment. Parameters calculated from the analytic signal are used as shape descriptors for the JT segment. The shape descriptors may be displayed in a dimensionality-reduced mapping. Templates representing characteristic shapes can be produced by finding cluster centres in the shape descriptor space, and the novelty of new waveforms can be quantified by comparing the position in shape descriptor space of new shape descriptors to a predefined normal training set or to previously encountered waveforms. Novel shape descriptors can be used to retrieve the corresponding waveforms, and templates of such novel shapes can be created by averaging such waveforms, using dynamic time warping to allow for variations in heart rate.

Abstract: A method of classifying arrhythmias using scatter plot analysis to define a measure of variability of a cardiac rhythm parameter such as for example, without limitation, R-R interval, A-A interval, and the slope of a portion of a cardiac signal, is disclosed. The variability measurement is derived from a scatter plot of a cardiac rhythm parameter, employing a region counting technique that quantifies the variability of the cardiac rhythm parameter while minimizing the computational complexity. The method may be employed by an implantable medical device or system, such as an implantable pacemaker or cardioverter defibrillator, or by an external device or system, such as a programmer or computer. The variability measurement may be correlated with other device or system information to differentiate between atrial flutter and atrial fibrillation, for example. The variability information may also be used by the device or system to select an appropriate therapy for a patient.

Abstract: In order to derive a standard 12-lead electrocardiogram, ones of limb leads and chest leads which constitute a lead system for the standard 12-lead electrocardiogram using 10 electrodes are selected. Electrocardiographic waveforms corresponding to the selected ones of the limb leads and the chest leads are obtained, as measured electrocardiographic waveforms, with electrodes attached on a living body. Electrocardiographic waveforms corresponding to a remaining ones of the limb leads and the chest leads are calculated, as non-measured electrocardiographic waveforms, with a prescribed transformation matrix and the measured electrocardiographic waveforms.

Abstract: The invention is related to a device and method for cordless recording, telecommunication transmission, and processing of three special ECG leads by the means of the mobile device (1) and diagnostic-calibration center (2) where the reconstruction of standard ECG leads is performed. Reconstruction parameters are determined previously by calibration for each patient. In urgent situation, a patient (3) performs recording of three special ECG leads with the mobile device (1), and sends the memorized data to the diagnostic-calibration device (2) via a cellular telephone (4). The patient can trace the process of recording and sending the data with the help of sound and light indicators. Diagnostic-calibration center (2) is equipped with a PC computer (6) connected to a receiving cellular telephone (7) and calibration ECG device (8) with 14 electrodes.

Abstract: A method of discriminating between ischemic and cardiac memory effects in a heart, comprising receiving electrocardiographic (ECG) data, calculating, from the ECG data, a direction of a T-wave vector, diagnosing ischemia if the T-wave vector is between about 75 degrees and about 200 degrees, and diagnosing cardiac memory if the T-wave vector is between about zero degrees and minus 90 degrees. Also presented is a system for discriminating between ischemic and cardiac memory effects in a heart comprising means for performing an electrocardiogram, means for calculating a direction of a T-wave vector, means for diagnosing ischemia if the T-wave vector is between about 90 degrees and 180 degrees, and means for diagnosing cardiac memory if the T-wave vector is between about zero degrees and minus 90 degrees.

Abstract: A magnetostrictive ultrasonic dental scaler is disclosed. The magnetostrictive device comprises an oscillator adapted to provide electrical energy including a current and a voltage signal, a handpiece having a tool tip which vibrates in response to the electrical energy supplied to the handpiece and a control circuit. The control circuit includes a phase detector adapted to detect phase between current and voltage signals and to generate a phase detection signal as a function of the phase. The control circuit also includes a digital signal processor operatively connected to the phase detector. The digital signal processor adapted to process the phase detection signal through a digital loop filter to generate an error signal.

Abstract: Four first electrodes are attached on right clavicle, the vicinity of on left clavicle, on right lowermost rib, and the position on left lowermost rib, corresponding to limb leads 12-lead electrocardiogram (ECG). Two second electrodes are attached on such positions of the living body that correspond to a lead V2 and a lead V4 of 12-lead ECG. First ECG data set correspond to leads I and II of 12-lead ECG. A second ECG data set including the leads V2 and V4. A heart vector is calculated on the first and second ECG data sets, and predetermined first lead vectors of leads I, II, V2 and V4. A third ECG data set including leads V1, V3, V5 and V6 is calculated based on the heart vector and predetermined second lead vectors of leads V1, V3, V5 and V6. A fourth ECG data set from leads III, aVR, aVL and aVF of 12-lead ECG based on the first ECG data set. The 12-lead ECG is derived based on the first to fourth ECG data sets.

Abstract: A system and method for classifying cardiac depolarization complexes in which waveforms of a depolarization complex are sensed by separate electrodes and correlated with template waveforms of a template depolarization complex. The system is particularly suitable for incorporation into a cardiac rhythm management device such as an implantable cardioverter/defibrillator or pacemaker in order to facilitate arrhythmia prediction and/or prevention.

Abstract: A method comprising sensing at least one cardiac signal representative of cardiac activity of a subject using an implantable medical device (IMD), calculating, from the cardiac signal, a first dominant vector corresponding to a direction and magnitude of maximum signal power of an ST-T first segment of a cardiac cycle and a second dominant vector corresponding to a direction and magnitude of maximum signal power of a P-QRS second segment of a cardiac cycle, measuring a change in the first dominant vector, measuring a change in the second dominant vector, and subtracting the change in the second dominant vector from the measured change in the first dominant vector to form a difference.

Abstract: A device for the analysis of an endocardiac signal of acceleration. The device preprocesses the acquired endocardiac acceleration (EA) signal by cutting the signal EA collected into sub-signals EA, each one have a duration of one cardiac cycle; separating the cut signals to isolate in each sub-signal EA at least one component EAx, associated with a major cardiac sound, and preferably into components EA1 and EA2 associated with the two major cardiac sounds S1 and S2; and performing a correlation on each component EA1 and EA2, to readjust each sub-signal in relation to a maximum of correlation, so as to deliver a readjusted component EA1 and a readjusted component EA2. The device further determines, starting from the isolated correlated components EA1 and EA2, a component average EA1 and a component average EA2, and to combine these components EA1 and average EA2 so as to produce an average global signal EA for one cycle.

Abstract: A system comprising a processor that includes a cardiac signal vector module and an ischemia detection module. The cardiac signal vector module is configured to measure a first dominant vector corresponding to a direction and magnitude of maximum signal power of a first segment of at least one cardiac cycle of a subject and at least a second dominant vector corresponding to a direction and magnitude of maximum signal power of a second segment of the cardiac cycle from an electrical cardiac signal. The ischemia detection module is configured to measure a change in the first dominant vector, to form a difference by subtracting a measured change in the second dominant vector from a measured change in the first dominant vector, and to declare whether an ischemic event occurred using the difference.

Abstract: The two ECG channels are graphed as an X-Y pair where the X coordinate is the voltage in a first ECG channel and the Y coordinate is the voltage in a second ECG channel. Because neither of the coordinates is a measure of time, the system and method can collect ECG data over an extended period and collapse the data into a single display region.

Abstract: It is an object of the invention to measure the change in action potential waveforms during administration of a drug by testing in cultured cells or in animals, and using this measurement to evaluate the influence of administration of the drug on biological parameters, thereby providing an approach to evaluating the effect on individual channels of a cell. The invention provides a biological parameter output apparatus that contains at least one piece of waveform information that includes at least one piece of biological parameter information, which is a set of a biological parameter identifier and a biological parameter value, and action potential waveform information, receives input of action potential waveform information, acquires at least one piece of biological parameter information based on the action potential waveform information, and outputs the at least one biological parameter information acquired.

Abstract: Cardiac monitoring and/or stimulation methods and systems that provide one or more of monitoring, diagnosing, defibrillation, and pacing. Cardiac signal separation is employed for automatic capture verification using cardiac activation sequence information. Devices and methods sense composite cardiac signals using implantable electrodes. A source separation is performed using the composite signals. One or more signal vectors are produced that are associated with all or a portion of one or more cardiac activation sequences based on the source separation. A cardiac response to the pacing pulses is classified using characteristics associated with cardiac signal vectors and the signals associated with the vectors. Further embodiments may involve classifying the cardiac response as capture or non-capture, fusion or intrinsic cardiac activity. The characteristics may include an angle or an angle change of the cardiac signal vectors, such as a predetermined range of angles of the one or more cardiac signal vectors.

Abstract: A method of determining a state of ventricular fibrillation, includes: measuring the rhythm of the heart during ventricular fibrillation for a period of time; creating a lagged phase space reconstruction of the measured rhythm; determining a first value related to the rate of change of the leading edge of the phase space reconstruction over the period of time; and determining the state of ventricular fibrillation by relating the first value to the state of ventricular fibrillation. A defibrillation system includes at least one processor in communication with a sensor to measure heart rhythm and an applicator to apply a defibrillation pulse. The processor is adapted to create a lagged phase space reconstruction of ventricular fibrillation heart rhythm and to determine a first value related to the rate of change of the leading edge of the phase space reconstruction over a period of time.

Abstract: According to the present invention, a Fourier transformation is executed on a time-concentration curve for an inflow artery and a time-concentration curve for each tissue on the basis of a dynamically acquired tomogram. An inverse filter is then calculated from the Fourier-transformed time-concentration curve for the inflow artery. The Fourier-transformed time-concentration curve for each tissue is multiplied by the inverse filter to generate a transfer function for the tissue. The thus generated transfer function for each tissue is used to calculate biological function information. Thus, if biological function information on an organ to be analyzed is to be obtained from a tomogram provided by a computer tomograph, very quantitative biological function information can be obtained at a low contrast rate. In particular, it takes only a minimum calculation time to obtain biological function information.