Abstract: A method of estimating cerebral blood flow by analyzing IPG and PPG signals of the head, the method comprising: a) finding a maximum slope or most negative slope or the IPG signal, within at least a portion of the cardiac cycle; b) finding a maximum slope or most negative slope of the PPG signal, within at least a portion of the cardiac cycle; c) finding a ratio of the maximum or most negative slope of the IPG signal to the maximum or most negative slope of the PPG signal; and d) calculating a cerebral blood flow indicator from the ratio.

Abstract: A method of estimating cerebral blood flow by analyzing IPG and PPG signals of the head, the method comprising: a) finding a maximum slope or most negative slope or the IPG signal, within at least a portion of the cardiac cycle; b) finding a maximum slope or most negative slope of the PPG signal, within at least a portion of the cardiac cycle; c) finding a ratio of the maximum or most negative slope of the IPG signal to the maximum or most negative slope of the PPG signal; and d) calculating a cerebral blood flow indicator from the ratio.

Abstract: A method of estimating at least one intracranial hemodynamic parameter in a subject, the method comprising: a) obtaining data of changes in electrical impedance across the subject's head as a function of time; b) analyzing the data; and c) estimating one or more of intracranial pressure, cerebral blood volume, and a factor related to at least one of cerebral perfusion pressure and a mean transit time through cerebral capillaries.

Abstract: A method of estimating at least one intracranial hemodynamic parameter in a subject, the method comprising: a) obtaining data of changes in electrical impedance across the subject's head as a function of time; b) analyzing the data; and c) estimating one or more of intracranial pressure, cerebral blood volume, and a factor related to at least one of cerebral perfusion pressure and a mean transit time through cerebral capillaries.

Abstract: A method of evaluating patients suspected of suffering from an acute stroke, the method comprising: a) obtaining signals of impedance plethysmography (IPG), photoplethysmography (PPG) or both, in the patient; b) processing the one or more signals to obtain one or more measures of cerebral hemodynamics of the patient; and c) applying a rule to match said measures to a disease indication or choice of therapy or both, for the patient.

Abstract: A method of monitoring an acute stroke patient, comprising: a) obtaining signals of impedance plethysmography (IPG), photoplethysmography (PPG) or both, in the patient, at least once an hour, for at least six hours; b) processing the one or more signals to obtain one or more measures of cerebral hemodynamics of the patient; c) applying a rule about alerting or not alerting medical personnel based on any of values, amount of change, and direction and rate of change of the measures.

Abstract: A method of finding an indication of a degree of cerebro-vascular bilateral asymmetry in a subject, comprising: a) measuring a first impedance waveform and a second impedance waveform of the subject's head as functions of time, in each case by finding a potential difference between two voltage electrodes associated with passing a given injected current through the head between at least two current electrodes, wherein in each case the voltage electrodes are located asymmetrically on the head, or the current is injected asymmetrically into the head, or both, and wherein the locations of the voltage electrodes and the distribution of current injection in measuring the second impedance waveform are minor images of what they are in measuring the first impedance waveform; and b) finding the indication of the degree of bilateral asymmetry from a difference between characteristics of the first and second impedance waveforms.

Abstract: A method of estimating cerebral blood flow by analyzing IPG and PPG signals of the head, the method comprising: a) finding a maximum slope or most negative slope or the IPG signal, within at least a portion of the cardiac cycle; b) finding a maximum slope or most negative slope of the PPG signal, within at least a portion of the cardiac cycle; c) finding a ratio of the maximum or most negative slope of the IPG signal to the maximum or most negative slope of the PPG signal; and d) calculating a cerebral blood flow indicator from the ratio.