Abstract: The present invention provides a system and method for representing quasi-periodic (“qp”) waveforms comprising, representing a plurality of limited decompositions of the qp waveform, wherein each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the qp waveform. These decompositions are stored into a data structure having a plurality of attributes. Optionally, these attributes are used to reconstruct the qp waveform, or patterns or features of the qp wave can be determined by using various pattern-recognition techniques. Some embodiments provide a system that uses software, embedded hardware or firmware to carry out the above-described method. Some embodiments use a computer-readable medium to store the data structure and/or instructions to execute the method.

Abstract: The present invention provides a system and method for representing quasi-periodic (“qp”) waveforms comprising, representing a plurality of limited decompositions of the qp waveform, wherein each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the qp waveform. These decompositions are stored into a data structure having a plurality of attributes. Optionally, these attributes are used to reconstruct the qp waveform, or patterns or features of the qp wave can be determined by using various pattern-recognition techniques. Some embodiments provide a system that uses software, embedded hardware or firmware to carry out the above-described method. Some embodiments use a computer-readable medium to store the data structure and/or instructions to execute the method.

Abstract: Medical devices and methods for making and using medical devices are disclosed. A method for removing an artifact of a biological reference signal present in a biological source signal may comprise sensing a biological reference signal with one or more electrodes and sensing a biological source signal, wherein the biological source signal comprises an artifact of the biological reference signal. The method may further comprise determining, based on the biological reference signal, the artifact of the biological reference signal and subtracting the artifact of the biological reference signal from the sensed biological source signal.

Abstract: A system and method for representing quasi-periodic (“qp”) waveforms, for example, representing a plurality of limited decompositions of the qp waveform. Each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the qp waveform. Data-structure attributes are created and used to reconstruct the qp waveform. Features of the qp wave are tracked using pattern-recognition techniques. The fundamental rate of the signal (e.g., heartbeat) can vary widely, for example by a factor of 2-3 or more from the lowest to highest frequency. To get quarter-phase representations of a component (e.g., lowest frequency “rate” component) that varies over time (by a factor of two to three) many overlapping filters use bandpass and overlap parameters that allow tracking the component's frequency version on changing quarter-phase basis.

Abstract: A system and method for representing quasi-periodic waveforms, for example, representing a plurality of limited decompositions of the quasi-periodic waveform. Each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the quasi-periodic waveform. Data-structure attributes are created and used to reconstruct the quasi-periodic waveform. Features of the quasi-periodic wave are tracked using pattern-recognition techniques. The fundamental rate of the signal (e.g., heartbeat) can vary widely, for example by a factor of 2-3 or more from the lowest to highest frequency. To get quarter-phase representations of a component (e.g.

Abstract: The present invention provides a system and method for representing quasi-periodic (“qp”) waveforms comprising, representing a plurality of limited decompositions of the qp waveform, wherein each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the qp waveform. These decompositions are stored into a data structure having a plurality of attributes. Optionally, these attributes are used to reconstruct the qp waveform, or patterns or features of the qp wave can be determined by using various pattern-recognition techniques. Some embodiments provide a system that uses software, embedded hardware or firmware to carry out the above-described method. Some embodiments use a computer-readable medium to store the data structure and/or instructions to execute the method.

Abstract: In a method for determining a cardiac condition, a sensed physiologic signal for a period of time including multiple cardiac cycles is received. Using the received physiologic data, a heart beat frequency to be used as a reference frequency is determined. A plurality of harmonics of the received physiologic signal is extracted based on the reference frequency, wherein the harmonics correspond to a plurality of alternans frequencies. Amplitudes of at least some of the extracted harmonics are determined, and are used to determine an alternans indicator value.

Abstract: The present invention provides a system and method for representing quasi-periodic (“qp”) waveforms comprising, representing a plurality of limited decompositions of the qp waveform, wherein each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the qp waveform. These decompositions are stored into a data structure having a plurality of attributes. Optionally, these attributes are used to reconstruct the qp waveform, or patterns or features of the qp wave can be determined by using various pattern-recognition techniques. Some embodiments provide a system that uses software, embedded hardware or firmware to carry out the above-described method. Some embodiments use a computer-readable medium to store the data structure and/or instructions to execute the method.

Abstract: The present invention provides a system and method for representing quasi-periodic (“qp”) waveforms comprising, representing a plurality of limited decompositions of the qp waveform, wherein each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the qp waveform. These decompositions are stored into a data structure having a plurality of attributes. Optionally, these attributes are used to reconstruct the qp waveform, or patterns or features of the qp wave can be determined by using various pattern-recognition techniques. Some embodiments provide a system that uses software, embedded hardware or firmware to carry out the above-described method. Some embodiments use a computer-readable medium to store the data structure and/or instructions to execute the method.

Abstract: The present invention provides a system and method for representing quasi-periodic (“qp”) waveforms comprising, representing a plurality of limited decompositions of the qp waveform, wherein each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the qp waveform. These decompositions are stored into a data structure having a plurality of attributes. Optionally, these attributes are used to reconstruct the qp waveform, or patterns or features of the qp wave can be determined by using various pattern-recognition techniques. Some embodiments provide a system that uses software, embedded hardware or firmware to carry out the above-described method. Some embodiments use a computer-readable medium to store the data structure and/or instructions to execute the method.

Abstract: The present invention provides a system and method for representing quasi-periodic (“qp”) waveforms comprising, representing a plurality of limited decompositions of the qp waveform, wherein each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the qp waveform. These decompositions are stored into a data structure having a plurality of attributes. Optionally, these attributes are used to reconstruct the qp waveform, or patterns or features of the qp wave can be determined by using various pattern-recognition techniques. Some embodiments provide a system that uses software, embedded hardware or firmware to carry out the above-described method. Some embodiments use a computer-readable medium to store the data structure and/or instructions to execute the method.

Abstract: The present invention provides a system and method for representing quasi-periodic (“qp”) waveforms comprising, representing a plurality of limited decompositions of the qp waveform, wherein each decomposition includes a first and second amplitude value and at least one time value. In some embodiments, each of the decompositions is phase adjusted such that the arithmetic sum of the plurality of limited decompositions reconstructs the qp waveform. These decompositions are stored into a data structure having a plurality of attributes. Optionally, these attributes are used to reconstruct the qp waveform, or patterns or features of the qp wave can be determined by using various pattern-recognition techniques. Some embodiments provide a system that uses software, embedded hardware or firmware to carry out the above-described method. Some embodiments use a computer-readable medium to store the data structure and/or instructions to execute the method.

Abstract: In a method for determining a cardiac condition, a sensed physiologic signal for a period of time including multiple cardiac cycles is received. Using the received physiologic data, a heart beat frequency to be used as a reference frequency is determined. A plurality of harmonics of the received physiologic signal is extracted based on the reference frequency, wherein the harmonics correspond to a plurality of alternans frequencies. Amplitudes of at least some of the extracted harmonics are determined, and are used to determine an alternans indicator value.

Abstract: A method of analyzing an elecotrocardiogram (ECG) waveform, the method including obtaining a series of digital values representing the ECG waveform having a plurality of cycles, with each cycle having a T-wave feature. The method includes comparing a first prototype wavelet to a portion of the series of digital values representing a selected number of cycles of the ECG waveform, wherein the first prototype wavelet is defined by a first set of wavelet parameters having an initial set of first parameter values, and adjusting the initial set of first parameter values to obtain a matched prototype wavelet defined by the first set of wavelet parameters having a matched set of first parameter values for each of the T-wave features of the selected number of cycles, wherein each matched prototype wavelet substantially matches the corresponding T-wave feature.

Abstract: A method of analyzing a signal, the method including obtaining a series of digital values representative of a quasi-period waveform having a plurality of cycles, with each cycle having at least a first target feature. The method includes comparing a first prototype wavelet to a portion of the series of digital values representing at least the first target feature of a selected number of cycles of the quasi-periodic waveform, wherein the first prototype wavelet is defined by a first set of wavelet parameters. A matched set of first parameter values is determined for the first set of wavelet parameters which define a matched wavelet for each of the first target features of the selected number of cycles, wherein each matched wavelet substantially matches the corresponding first target feature.

Abstract: A low pass filter especially adapted for use with ECG equipment designed to negate any noise energy that may be superimposed upon the ECG signal itself. A plurality of low-pass FIR filter stages are connected in tandem between a signal input point and a signal output point where each of the stages has a distinct cut-off frequency characteristic. Means are provided for selectively turning ones of the plurality of stages on or off.

Abstract: A low pass filter especially adapted for use with ECG equipment designed to negate any noise energy that may be superimposed upon the ECG signal itself. A plurality of low-pass FIR filter stages are connected in tandem between a signal input point and a signal output point where each of the stages has a distinct cut-off frequency characteristic. Means are provided for selectively turning ones of the plurality of stages on or off.

Abstract: A low pass filter especially adapted for use with ECG equipment designed to negate any noise energy that may be superimposed upon the ECG signal itself. A plurality of low-pass FIR filter stages are connected in tandem between a signal input point and a signal output point where each of the stages has a distinct cut-off frequency characteristic. A device is provided for selectively turning ones of the plurality of stages on or off.

Abstract: A method and apparatus for automatic gain control (AGC) method are provided to control the output from a medical device monitoring electrical potentials. The AGC method and apparatus accumulate data indicative of at least one vector in a cycle buffer, calculate an amplitude representative of the signal, compare the calculated value with a set of thresholds, and calculate an adjustment to the gain setting based on the amplitudes relationship to the thresholds.

Abstract: A method and apparatus for automatic gain control (AGC) method are provided to control the output from a medical device monitoring electrical potentials. The AGC method and apparatus accumulate data indicative of at least one vector in a cycle buffer, calculate an amplitude representative of the signal, compare the calculated value with a set of thresholds, and calculate an adjustment to the gain setting based on the amplitudes relationship to the thresholds.