Abstract: Disclosed is a cardiac biopotential analysis system and method for detecting and quantifying in a noninvasive manner nonlinear dynamic patterns of depolarization and repolarization on a beat to beat basis in real time using bispectral analysis. A suitable body surface electrode acquires the signal from a region of interest. The signal is then amplified, digitized, and transmitted to a host microcomputer where an arrhythmia-free QRST complex is chosen interactively. Using standard cross-correlation methods a suitable number of complexes are extracted from the record. The extracted complexes are used to compute bispectral parameters using a frequency domain or a parametric based approach. A reference clinical database is used to identify frequency pairs most sensitive to particular interventions or diagnostic states of interest. The values at these frequency pairs are then extracted from the patient's bispectral arrays.

Abstract: Disclosed is a real time cerebral diagnostic apparatus and method for quantitatively evaluating, in a noninvasive manner, cerebral phenomena such as the depth and adequacy of anesthesia pain responses during surgical stress, acute cerebral ischemia, level of consciousness, degree of intoxication and ongoing normal and abnormal cognitive processes. A suitable electrode and amplifier system is used to obtain high resolution biopotentials from the regions of interest. Surface electroencephalographic (EEG) signals are filtered to allow the acquisition of frequencies between 2 and 500 Hz, then digitized and transmitted over a high speed serial line to a host computer where a 32 second long signal is divided into 128 consecutive 0.25 second intervals. Digital EEG data from unipolar leads is normalized and the dynamic phase and density relations within the signal are then characterized by estimating the third-order autocorrelation function or autobispectrum using either a frequency domain, or parametric approach.

Abstract: Disclosed is a cardiac biopotential analysis system and method for detecting, in a noninvasive manner, the degree of myocardial ischemia and the amount of cardiac electrophysiologic stability present in a subject. A suitable body surface electrode acquires the signal from a region of interest. The body surface electrocardiographic signals are then amplified, digitized and transmitted to a host computer where an arrhythmia free QRST complex template is chosen interactively. Using cross-correlation, 50 subsequent complexes that mask the template are extracted. A Fast Fourier Transform (FFT) is then performed on every beat. The FFT results of every QRST are used to produce a bispectral complex and real triple product arrays. Each point in these arrays is then averaged over the 50 previously acquired QRST complexes.

Abstract: Disclosed is a biopotential analysis system and method of the present invention for determining, in a noninvasive manner, cerebral electrical properties. A suitable electrode and amplifier system is used to obtain biopotentials from the region of interest. Surface electroencephalographic signals are then digitized and transmitted over a serial RS232C line to a host computer where a two minute long signal is divided into 30 consecutive four second intervals. A fast Fourier transform (FFT) is then performed on every interval, and the resulting fast Fourier transforms are then used to produce bispectral complex triple product and bispectral real triple product arrays for that interval. The complex triple product arrays of all intervals are added together, and the real triple product arrays of all intervals are also added together.