Abstract: Techniques for orientation determination cause emitters of a multi-sensor imaging apparatus to emit a first set of ultrasound signals; measuring arrival times and amplitudes of the first set of ultrasound signals; estimating initial locations of the sensors; pointing each of the sensors towards a center mass location; fitting an initial orientation to each of the sensors and to each of the emitters using a loss function; determining a coarse model based on the initial locations of the sensors and initial locations of the emitters; calculating a new location and a new orientation for each of the sensors and each of the emitters based on the coarse model and a second set of ultrasound signals; employing a full wave inversion to generate an updated model; and determining an orientation of each of the sensors and emitters based on the updated model. Embodiments may include filtering out outlier sensor-emitter pairs.

Abstract: A method for measuring an intracranial bioimpedance in a patient's head, to help evaluate cerebral autoregulation, may involve securing a volumetric integral phase-shift spectroscopy (VIPS) device to the patient's head, measuring the intracranial bioimpedance with the VIPS device by measuring a phase shift between a magnetic field transmitted from a transmitter on one side of a VIPS device and a magnetic field received at a receiver on another side of the VIPS device, at one or more frequencies, and evaluating cerebral autoregulation in the intracranial bioimpedance, using a processor in the VIPS device.

Abstract: A method for measuring an intracranial bioimpedance in a patient's head, to help evaluate cerebral autoregulation, may involve securing a volumetric integral phase-shift spectroscopy (VIPS) device to the patient's head, measuring the intracranial bioimpedance with the VIPS device by measuring a phase shift between a magnetic field transmitted from a transmitter on one side of a VIPS device and a magnetic field received at a receiver on another side of the VIPS device, at one or more frequencies, and evaluating cerebral autoregulation in the intracranial bioimpedance, using a processor in the VIPS device.