Abstract: An improved apparatus and method for determining the cardiac output of a living subject. The improved apparatus generally comprises one or more electrode assemblies or patches affixed to the skin of the subject in the vicinity of the thoracic cavity. In one embodiment, the apparatus comprises a constant current source impedance cardiography (ICG) monitor adapted as a stand-alone system. In another embodiment, the apparatus comprises a module adapted for use with a host monitoring system, the latter providing ECG, blood pressure, and/or other inputs to the module. Method of detecting a loss of electrical continuity in one or more of the terminals of the electrode patch, and selecting between a plurality of signal inputs based on signal quality, are also disclosed.

Abstract: An improved apparatus and method for determining the cardiac output of a living subject. The improved apparatus generally comprises one or more electrode assemblies or patches affixed to the skin of the subject in the vicinity of the thoracic cavity. In one embodiment, the apparatus comprises a constant current source impedance cardiography (ICG) monitor adapted as a stand-alone system. In another embodiment, the apparatus comprises a module adapted for use with a host monitoring system, the latter providing ECG, blood pressure, and/or other inputs to the module. Method of detecting a loss of electrical continuity in one or more of the terminals of the electrode patch, and selecting between a plurality of signal inputs based on signal quality, are also disclosed.

Abstract: An improved method and apparatus for non-invasively assessing one or more hemodynamic parameters associated with the circulatory system of a living organism. In one exemplary embodiment, the invention comprises a method of measuring cardiac output (CO) using impedance waveforms (and ECG waveforms) which are analyzed via discrete wavelet transforms. These transforms aid in identifying fiducial points within the waveforms, the fiducial points being used to calculate various parameters relating to cardiac stroke volume (such as LVET and dZ/dtmax), from which cardiac output may be determined. The use of wavelet transforms for fiducial point detection increases the accuracy of the CO determination by reducing cross-term artifact, and also significantly reduces the amount and complexity of processing required as compared to prior art time-frequency distribution or empirical techniques. Improved methods of QRS complex detection within the ECG waveform, and median filtering of an input waveform, are also disclosed.

Abstract: An improved method and apparatus for non-invasively assessing one or more hemodynamic parameters associated with the circulatory system of a living organism. In one exemplary embodiment, the invention comprises a method of measuring cardiac output (CO) using impedance waveforms (and ECG waveforms) which are analyzed via discrete wavelet transforms. These transforms aid in identifying fiducial points within the waveforms, the fiducial points being used to calculate various parameters relating to cardiac stroke volume (such as LVET and dZ/dtmax), from which cardiac output may be determined. The use of wavelet transforms for fiducial point detection increases the accuracy of the CO determination by reducing cross-term artifact, and also significantly reduces the amount and complexity of processing required as compared to prior art time-frequency distribution or empirical techniques. Improved methods of QRS complex detection within the ECG waveform, and median filtering of an input waveform, are also disclosed.