Abstract: A computerized system for locating a device including a sensor module and a processor. A radioactive source, associated with the device, produces a signal in the form of radioactive disintegrations. The sensor module includes a radiation detector capable of receiving a signal from the source attached to the device. The sensor module produces an output signal. The processor receives output signal(s) and translates output into information relating to a position of source.

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 estimating blood flow in the brain, comprising: a) causing currents to flow inside the head by producing electric fields inside the head; b) measuring at least changes in the electric fields and the currents; and c) estimating changes in the blood volume of the head, using the measurements of the electric fields and the currents.

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 estimating blood flow in the brain, comprising: a) causing currents to flow inside the head by producing electric fields inside the head; b) measuring at least changes in the electric fields and the currents; and c) estimating changes in the blood volume of the head, using the measurements of the electric fields and the currents.

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 computerized system 40 for locating a device. System 40 includes a sensor module 20 and a CPU 42. A radioactive source 38, associated with the device, produces a signal in the form of radioactive disintegrations. Module 20 includes a radiation detector 22 capable of receiving a signal from source 38 attached to the device. Module 20 produces an output signal 34. CPU 42 receives output signal(s) 34 and translates output 34 into directional information relating to a position of source 38.

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 includes obtaining a measure of time-varying blood volume in the head, using an impedance plethysmography (102 and 104), obtaining a measure of time-varying blood volume in the scalp, and using the time-varying blood volume in the head and scalp to estimate cerebral blood flow.

Abstract: A method of determining a position of a second object which travels along a first object. The method comprising determining a position for a first object; determining a linear displacement of a second object relative to the first object; and ascertaining a position of said second object based upon said relative linear displacement and said position of said first object.

Abstract: A method of estimating blood flow in a brain, comprising: a) causing currents to flow inside the head by producing electric fields inside the head; b) measuring at least changes in the electric fields and the currents; c) estimating changes in the blood volume of the head, using the measurements of the electric fields and the currents, where the current are produced in children or using electrodes at or near holes in the skull. Optionally, the configuration is selected to focus the flow of current to be inside the brain to a significant degree.

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 computerized system 40 for locating a device. System 40 includes a sensor module 20 and a CPU 42. A radioactive source 38, associated with the device, produces a signal in the form of radioactive disintegrations. Module 20 includes a radiation detector 22 capable of receiving a signal from source 38 attached to the device. Module 20 produces an output signal 34. CPU 42 receives output signal(s) 34 and translates output 34 into directional information relating to a position of source 38.

Abstract: A method of estimating blood flow in the brain, comprising: a) causing currents to flow inside the head by producing electric fields inside the head; b) measuring at least changes in the electric fields and the currents; and c) estimating changes in the blood volume of the head, using the measurements of the electric fields and the currents.