Techniques are described to determine a location of at least one oscillatory signal source in a patient. Processing circuitry may determine expected electrical signal levels based on a hypothetical location of the at least one oscillatory signal source. Processing circuitry may determine the electrical signal levels and determine an error value based on the expected electrical signal levels and the determined electrical signal levels. Processing circuitry may adjust the hypothetical location of the at least one oscillatory signal source until the error value is less than or equal to a threshold value, including the example where the error value is minimized.

Magnetic resonance methods comprise tractographically establishing a path along a structure in a specimen and finding a distribution of structure radii or cross-sectional areas along the path. Based on the distribution and the path, end-to-end functional characteristics of the structure are estimated. For example, nerve transit times or distributions of transit times can be estimated for a plurality of nervous system locations such as Brodmann areas. Comparison of estimated transit times or distributions thereof between reference values or other values from the same structure can be used to assess specimen health.

Devices and methods provide for the sensing of physiological signals during stimulation therapy by preventing stimulation waveform artifacts from being passed through to the amplification of the sensed physiological signal. Thus, the amplifiers are not adversely affected by the stimulation waveform and can provide for successful sensing of physiological signals between stimulation waveform pulses. A blanking switch may be used to blank the stimulation waveform artifacts where the blanking switch is operated in a manner synchronized with the stimulation waveform so that conduction in the sensing path is blocked during the stimulation pulse as well as during other troublesome artifacts such as a peak of a recharge pulse. A limiter may be used to limit the amplitude of the sensed signal, and hence the stimulation artifacts, that are passed to the amplifier without any synchronization of the limiter to the stimulation waveform.

The exemplified methods and systems provide a phase space volumetric object in which the dynamics of a complex, quasi-periodic system, such as the electrical conduction patterns of the heart, or other biophysical-acquired signals of other organs, are represented as an image of a three dimensional volume having both a volumetric structure (e.g., a three dimensional structure) and a color map to which features can be extracted that are indicative the presence and/or absence of pathologies, e.g., ischemia relating to significant coronary arterial disease (CAD). In some embodiments, the phase space volumetric object can be assessed to extract topographic and geometric parameters that are used in models that determine indications of presence or non-presence of significant coronary artery disease.

Concepts presented herein relate to an interface module that can be electrically coupled to an electrical stimulation generator, a radio frequency generator and an instrument. A selection module is coupled to the interface module and operates in a first mode to deliver electrical stimulation signals from the electrical stimulation generator to the instrument and in a second mode to deliver radio frequency signals from the radio frequency generator to the instrument.

The techniques described herein are example medical devices, systems, and methods for sensing evoked potentials in a tissue of the patient, and, based on the sensed evoked potentials, adjusting one or more parameters defining the electrical stimulation therapy delivered to the patient. In one example, a system controls delivery of an electrical stimulation therapy from an implantable medical device to a patient according to at least one therapy program, wherein the electrical stimulation therapy is configured to provide pain relief to the patient without substantially resulting in paresthesia perceived by the patient. The system periodically adjusts the electrical stimulation therapy delivered to the patient in response to detected compound action potentials, wherein the adjustment to the electrical stimulation therapy is configured to eliminate action potentials in tissue of the patient evoked by the delivered electrical stimulation, and wherein the controlling and the adjusting are performed via one or more processors.

An ocular cranial nerve monitoring system (OCNMS) that provides continuous measurement of pupillary reactivity in the eye. The system features a sensor component that produces a stimulating light and a recording light and records reflected recording light so as to calculate pupillary diameter and response to stimulation as measured by latency, velocity, and/or amplitude. This system of the present invention may be used for indirect assessment of the 2nd and 3rd cranial nerve (CN 2, CN3) pathways and/or intracranial pressure in patients and may be used intraoperatively. The data obtained from this system may allow for immediate corrective actions, which may help prevent permanent deficits and improve patient safety and surgical outcomes. In some instances, the system may help avoid unnecessary or invasive procedures (e.g., catheters inserted for intracranial pressure monitoring).

Provided is a method of analyzing electrical characteristics of nerves, the method including generating an input electrical signal to be applied to a nerve, obtaining an output electrical signal based on measuring a nerve signal generated from the nerve in response to the input electrical signal, obtaining output frequency components, which are frequency components of the output electrical signal, based on converting the output electrical signal into a frequency domain, and obtaining conductance of the nerves and capacitance of the nerves based on the output frequency components.

Systems, devices, and methods for neurostimulation using a combination of implantable and external devices to treat pain are disclosed.

An Implantable Pulse Generator (IPG) is disclosed that is capable of sensing a degree to which recruited neurons in a patient's tissue are firing synchronously, and of modifying a stimulation program to promote desynchronicity and to reduce paresthesia. An evoked compound action potential (ECAP) of the recruited neurons is sensed as a measure of synchronicity by at least one non-active electrode. An ECAP algorithm operable in the IPG assesses the shape of the ECAP and determines one or more ECAP shape parameters that indicate whether the recruited neurons are firing synchronously or desynchronously. If the shape parameters indicate significant synchronicity, the ECAP algorithm can adjust the stimulation program to promote desynchronous firing.