Abstract: The present invention relates to measuring electrical impedance, and particularly to measuring impedance of electrodes used to acquire physiological signals. The measurement of electrode impedance is typically performed to ensure proper electrode-to-skin contact, and thus verify the quality of the acquired signals. Electrode-to-skin contact impedance has also clinical utility for monitoring, diagnosis, prognosis or treatment, as it can be used to measure skin conductivity, which is function of physiological processes. The present invention relates in particular to a substantially continuous method for performing such measurement. The measurement is performed in such a way that it does not affect the bioband, the range (or ranges) of frequencies that contains components used for diagnostic, prognostic, triage, and/or treatment purposes. The present invention therefore performs this impedance measurement without affecting the physiological signal while allowing for uninterrupted monitoring of said signal.

Abstract: The present invention relates to measuring electrical impedance, and particularly to measuring impedance of electrodes used to acquire physiological signals. The measurement of electrode impedance is typically performed to ensure proper electrode-to-skin contact, and thus verify the quality of the acquired signals. Electrode-to-skin contact impedance has also clinical utility for monitoring, diagnosis, prognosis or treatment, as it can be used to measure skin conductivity, which is function of physiological processes. The present invention relates in particular to a substantially continuous method for performing such measurement. The measurement is performed in such a way that it does not affect the bioband, the range (or ranges) of frequencies that contains components used for diagnostic, prognostic, triage, and/or treatment purposes. The present invention therefore performs this impedance measurement without affecting the physiological signal while allowing for uninterrupted monitoring of said signal.

Abstract: The present invention, herein is a method and apparatus that significantly limits the effect of high frequency (“HF”) interferences on acquired electro-physiological signals, such as the EEG and EMG. Preferably, this method comprises of two separate electronic circuitries and steps or electronics for processing the signals. One circuit is used to block the transmission of HF interferences to the instrumentation amplifiers. It is comprised of a front-end active filter, a low frequency electromagnetic interference (“EMI”) shield, and an isolation barrier interface which isolates the patient from earth ground. The second circuit is used to measure the difference in potential between the two isolated sides of the isolation barrier. This so-called “cross-barrier” voltage is directly representative of the interference level that the instrumentation amplifier is subjected to. This circuit is used to confirm that the acquired signals are not corrupted by the interference.

Abstract: The present invention, herein is a method and apparatus that significantly limits the effect of high frequency (“HF”) interferences on acquired electro-physiological signals, such as the EEG and EMG. Preferably, this method comprises of two separate electronic circuitries and steps or electronics for processing the signals. One circuit is used to block the transmission of HF interferences to the instrumentation amplifiers. It is comprised of a front-end active filter, a low frequency electromagnetic interference (“EMI”) shield, and an isolation barrier interface which isolates the patient from earth ground. The second circuit is used to measure the difference in potential between the two isolated sides of the isolation barrier. This so-called “cross-barrier” voltage is directly representative of the interference level that the instrumentation amplifier is subjected to. This circuit is used to confirm that the acquired signals are not corrupted by the interference.

Abstract: The present invention relates to a physiological monitor and system, particularly to an electroencephalogram (EEG) monitor and system, and a method of detecting the presence and absence of artifacts and possibly removing artifacts from an EEG, other physiological signal or sensor signal without corrupting or compromising the signal. The accurate, real-time detection of the presence or absence of artifacts and removal of artifacts in EEG or other signals allows for increased reliability in the efficacy of those signals. The strategy of rejecting artifact-corrupted EEG can result in unacceptable data loss, and asking subjects to minimize movements in order to minimize artifacts is not always feasible. The present invention allows for increased accuracy in detection and removal of artifacts from physiological signals, substantially in real time, and without loss or corruption of signal or data in order to increase the accuracy of such signals for diagnosis and treatment purposes.

Abstract: The present invention relates to a method of signal processing of electrograms for use in medical devices, preferably by time-frequency transforms. The present invention additionally relates to a system for receiving and analyzing such signals. The present invention preferably is a method utilizing the time-frequency transforms, such as wavelet transforms, for the purpose of artifact removal from EGs. These transforms decompose a signal in both time and frequency domains, and therefore, are well suited for non-stationary signal analysis. As a result, dissimilar signal features are well localized both in time and frequency, which potentially provides a good separation between the signal of interest and artifacts. This particularly applies to large-amplitude artifacts corrupting EGs.

Abstract: The present invention, herein is a method and apparatus that significantly limits the effect of high frequency (“HF”) interferences on acquired electro-physiological signals, such as the EEG and EMG. Preferably, this method comprises of two separate electronic circuitries and steps or electronics for processing the signals. One circuit is used to block the transmission of HF interferences to the instrumentation amplifiers. It is comprised of a front-end active filter, a low frequency electromagnetic interference (“EMI”) shield, and an isolation barrier interface which isolates the patient from earth ground. The second circuit is used to measure the difference in potential between the two isolated sides of the isolation barrier. This so-called “cross-barrier” voltage is directly representative of the interference level that the instrumentation amplifier is subjected to. This circuit is used to confirm that the acquired signals are not corrupted by the interference.

Abstract: A method and apparatus to monitor the neurologic state of a patient undergoing general anesthesia is provided. Previous automated systems to monitor the neurologic state of a patient undergoing general anesthesia involve a significant time delay between the patients true hypnotic state and the computed indices. The present invention reduces this time delay by using a different analysis technique applied to spontaneous EEG. A wavelet decomposition and statistical analysis of the observed EEG is conducted and compared to reference data to provide a numerical indicator. In addition, this indicator is more consistent with the patient's loss of consciousness indicated by the loss of count event than previous systems.

Abstract: A method and apparatus to monitor the neurologic state of a patient undergoing general anesthesia is provided. Previous automated systems to monitor the neurologic state of a patient undergoing general anesthesia involve a significant time delay between the patient's true hypnotic state and the computed indices. The present invention reduces this time delay by using a different analysis technique applied to spontaneous EEG. A wavelet decomposition and statistical analysis of the observed EEG is conducted and compared to reference data to provide a numerical indicator. In addition, this indicator is more consistent with the patient's loss of consciousness indicated by the loss of count event than previous systems.