Abstract: Devices, and methods for measuring bioimpedance signals are disclosed. One aspect may include a headset apparatus including a retainer and electrodes. The retainer may be configured to position the electrodes on the head of a subject so as to obtain bioimpedance signals indicative of hemodynamic conditions associated with an MCA territory. A processor may be included to measure and analyze the obtained bioimpedance signals, and to output information for predicting hemodynamic conditions associated with an MCA territory.

Abstract: Devices, and methods for monitoring cerebro-hemodynamic signals are disclosed. In one aspect, the devices and methods may include receiving at least one signal characterizing a bioimpedance measurement. The at least one signal may be correlated with the timing of a cardiac wave and analyzed to ascertain an extent of an expected characteristic within the signal. The extent of the expected characteristic may be used to provide information for predicting a physiological brain condition. The at least one signal may include two signals, obtained from opposite brain hemispheres, and may be a bioimpedance signal.

Abstract: A traumatic brain injury diagnostic system may comprise a current transmission unit, a voltage detection unit, a demodulation unit, and at least one processor. The current transmission unit may output an electric current to at least a first pair of electrodes attached to a head of a subject. The voltage detection unit may detect a voltage via at least a second pair of electrodes attached to the head of the subject proximal to the first pair of electrodes. The demodulation unit may extract an electrical impedance signal from an output electric current of the current transmission unit and the detected voltage of the voltage detection unit. The processor may perform operations to diagnose traumatic brain injury including comparing a static component of the electrical impedance signal to a pre-defined threshold and comparing a dynamic component of the electrical impedance signal to a pre-defined dynamic value.

Abstract: Devices and methods are disclosed for detecting and/or monitoring cerebral pathologies. In one embodiment, a cerebro-hemodynamic measurement apparatus is disclosed that includes at least one processor. The at least one processor is configured to receive, via at least one sensor, at least one signal associated with a brain of a subject. The at least one processor is configured to determine, based on the at least one signal, a change in cerebral blood volume caused by a cardiac pulsation. The at least one processor is configured to determine, based on the at least one signal, a change in intracranial pressure due to cardiac pulsation. The at least one processor is also configured to estimate mean intracranial pressure based on changes in the cerebral blood volume, changes in the intracranial pressure, and a compliance indicator.

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 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 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: Devices and methods for monitoring intracranial physiological parameters, including intracranial pressure, cerebral perfusion pressure, cerebral blood flow, cerebral blood volume, edema status, and brain compliance are disclosed. In one aspect, an apparatus may involve receiving at least one impedance plethysmography signal. Waveforms may be extracted from the impedance plethysmography signals and used for estimating the intracranial physiological parameters. Various characteristics may be determined from the waveforms to aid in the estimation of intracranial physiological parameters.

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: Devices and methods for monitoring intracranial hemodynamic parameters, such as intracranial pressure, cerebral blood volume, cerebral blood flow, and cerebral perfusion pressure are disclosed. In one aspect, the devices and methods may involve receiving at least one impedance plethysmography signal. Waveforms may be extracted from the impedance plethysmography signals and used for estimating the intracranial hemodynamic parameters. Various characteristics may be determined from the waveforms to aid in the estimation of intracranial hemodynamic parameters.

Abstract: A system and method is provided for determining a route to a target. The system can include a display device, where the display device can be operable to display a graphical representation of a 3 dimensional model of a portion of a vasculature of a body. Further, the display device can be operable to allow a user to select a target location on the 3 dimensional model. Further still, the display device can be operable to automatically determine an intravascular route to the target location using the 3-dimensional model, or it can be operable to allow the user to manually determine an intravascular route to the target location using the graphical representation of the 3-dimensional model.

Abstract: A system and method is provided for guiding the navigation of intravascular medical tools. The system can include a display device operable to store information relating to a 3-dimensional model of a portion of vasculature of a body in a region of the body and operable to store information relating to a 3-dimensional position of a tool, where the tool is located within the portion of the vasculature of the body. In addition, the display device can be operable to display a graphical representation of the 3-dimensional model and a graphical representation of the tool visually integrated with the graphical representation of the 3-dimensional model. Furthermore, the display device can be operable to update at least the graphical representation of the tool based at least in part upon updated information relating to the 3-dimensional position of the tool.

Abstract: A system and method is provided for automatic navigation of medical tools. The system can include a tracking system operable to provide information relating to the position of at least a portion of a tool which is inside a body, and an automated navigation system operable to apply forces upon a portion of the tool. The automated navigation system can include a computer operable to store a 3-dimensional route. Furthermore, the automated navigation system can be operable to use the information relating to the position of at least the portion of the tool from the tracking system to apply calculated forces upon the tool, the calculated forces being associated with movement of the tool along the 3-dimensional route.

Abstract: Devices, and methods for receiving and comparing bioimpedance signals are disclosed. In one aspect, the devices and methods may include receiving bioimpedance signals indicative of hemodynamic characteristics within a subject's brain. Bioimpedance signals may be compared, and the comparison used to provide information for diagnosing changes in arterial occlusion. Bioimpedance signals may be associated with left and right sides of a subject's brain. Signature features within the bioimpedance signals may be detected and used to determine differences in the bioimpedance signals.

Abstract: Devices, and methods for monitoring cerebro-hemodynamic signals are disclosed. In one aspect, the devices and methods may include receiving at least one signal characterizing a bioimpedance measurement. The at least one signal may be correlated with the timing of a cardiac wave and analyzed to ascertain an extent of an expected characteristic within the signal. The extent of the expected characteristic may be used to provide information for predicting a physiological brain condition. The at least one signal may include two signals, obtained from opposite brain hemispheres, and may be a bioimpedance signal.

Abstract: Devices, and methods for measuring bioimpedance signals are disclosed. One aspect may include a headset apparatus including a retainer and electrodes. The retainer may be configured to position the electrodes on the head of a subject so as to obtain bioimpedance signals indicative of hemodynamic conditions associated with an MCA territory. A processor may be included to measure and analyze the obtained bioimpedance signals, and to output information for predicting hemodynamic conditions associated with an MCA territory.

Abstract: Devices, and methods for synchronizing cerebro-hemodynamic signals are disclosed. In one aspect, the devices and methods may include synchronizing first and second signals indicative of hemodynamic characteristics within a subject's brain. Differences may be determined between the synchronized signals and used to provide information for diagnosing changes in arterial occlusion. Differences between the synchronized signals may include differences, such as timing delays, between signature features of the synchronized signals. The first and second signals may be indicative of hemodynamic characteristics in first and second hemisphere's of a subject's brain. The first and second signals may be bioimpedance signals.

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 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.