Abstract: A method of locating a nerve within an intracorporeal treatment area of a subject includes providing a first electrical stimulus at a first location within the intracorporeal treatment area, providing a second electrical stimulus at a second location within the intracorporeal treatment area, and providing one or more additional electrical stimuli at the second location. The first electrical stimulus does not induce a threshold response of a muscle innervated by the nerve, whereas the second electrical stimulus does induce a response of the muscle. The one or more additional stimuli each have a current magnitude less than the first stimulus and are used to determine a minimum current magnitude that is required to induce the threshold response of the muscle at the second location. This minimum current magnitude is then used to determine a distance from the second location to the nerve.

Abstract: A neural monitoring system includes an elongate medical instrument, a non-invasive mechanical sensor, and a processor. The elongate medical instrument has a distal end portion configured to extend within an intracorporeal treatment area of a subject, and a plurality of electrodes disposed on the distal end portion. Each electrode is respectively configured to provide an electrical stimulus. The non-invasive mechanical sensor is configured to be placed in mechanical communication with a muscle of the subject and to generate a mechanomyography output signal corresponding to a sensed mechanical movement of the muscle. The processor is provided in communication with the elongate medical instrument and the mechanical sensor, and is configured to receive the mechanomyography output signal, and determine a relative direction between a nerve and the distal end portion of the elongate medical instrument using the received mechanomyography output signal.

Abstract: A method of modeling a nerve disposed within an intracorporeal treatment area of a patient includes locating an electrode at a plurality of locations within a virtual workspace and providing an electrical stimulus from the electrode to the intracorporeal treatment area. The response of a muscle to the electrical stimulus is monitored and used to determine a distance to the nerve from each of the plurality of locations. A virtual model of the nerve is then constructed within the virtual workspace using the determined distance to the nerve from each of the different positions, and the plurality of locations within the virtual workspace.

Abstract: A method of locating a nerve within an intracorporeal space includes advancing a distal end portion of a stimulator toward an anatomical target within the intracorporeal space, and periodically applying a first electrical stimulus from a first electrode disposed on a central axis of the stimulator. If a muscular response to the first electrical stimulus is detected, a locating electrical stimulus is then applied from a plurality of locations offset from the central axis of the stimulator, and a magnitude of the response of the muscle is monitored. A distance between the nerve and each of the plurality of locations is determined from the magnitude of the muscular response, and from a magnitude of the locating electrical stimulus provided at each of the plurality of locations. The location of the nerve is then triangulated from the determined distance at each of the plurality of locations.

Abstract: A nerve mapping system includes a plurality of electrodes, a sensor, and a processor in communication with each of the plurality of electrodes and the sensor. Each electrode is disposed on the distal end portion of one or more elongate medical devices configured to extend within an intracorporeal treatment area of a subject. The sensor is in communication with a muscle of a subject, and is configured to provide an output signal corresponding to a monitored response of the muscle. The processor receives an indication of the location of each electrode and an indication of a magnitude of the monitored muscular response. Using these parameters, the processor determines a distance to the nerve from the location of each of the plurality of electrodes, and constructs a virtual model of the nerve using the determined distance to the nerve at each of the plurality of locations.

Abstract: A method of identifying a change in the health of a nerve during a surgical procedure includes determining a sensitivity of the nerve at a first time, determining a sensitivity of the nerve at a second time, and providing an indication to a user corresponding to a change in the sensitivity of the nerve from the first time to the second time. In each instance, the sensitivity of the nerve is determined by providing an electrical stimulus via an electrode disposed on a distal end portion of an elongate medical instrument, and monitoring a magnitude of a mechanical response of a muscle innervated by the nerve.

Abstract: A neural monitoring device includes a stimulator configured to provide a stimulus, a mechanical sensor configured to generate an output signal corresponding to a sensed event, and a receiver configured to receive an output signal from the mechanical sensor and determine if the output signal corresponds to the stimulus provided by the stimulator.

Abstract: A method of detecting the presence of a sacral nerve in a human subject includes providing an electrical stimulus within an intracorporeal treatment area of the human subject; detecting a physical response of at least one of an external sphincter of the bladder and an external sphincter of the anus; and providing an indication to a user if the detected physical response corresponds to the provided electrical stimulus.

Abstract: A neural monitoring system includes an elongate medical instrument, a non-invasive mechanical sensor, and a processor. The elongate medical instrument has a distal end portion configured to extend within an intracorporeal treatment area of a subject, and a plurality of electrodes disposed on the distal end portion. Each electrode is respectively configured to provide an electrical stimulus. The non-invasive mechanical sensor is configured to be placed in mechanical communication with a muscle of the subject and to generate a mechanomyography output signal corresponding to a sensed mechanical movement of the muscle. The processor is provided in communication with the elongate medical instrument and the mechanical sensor, and is configured to receive the mechanomyography output signal, and determine a relative direction between a nerve and the distal end portion of the elongate medical instrument using the received mechanomyography output signal.

Abstract: A neural monitoring system for determining a proximity between a stimulator and a nerve within an intracorporeal treatment area of a human subject includes a stimulator, a mechanical sensor, and a receiver. The stimulator is configured to extend within the intracorporeal treatment area and to provide an electrical stimulus therein. The mechanical sensor is configured to be placed in mechanical communication with the muscle and to generate a mechanomyography output signal corresponding to a sensed mechanical movement of the muscle. The receiver is configured to: receive the mechanomyography output signal from the mechanical sensor; receive an indication of a magnitude of the provided intracorporeal stimulus; determine a magnitude of acceleration of the muscle from the received mechanomyography output signal; and determine a proximity between the stimulator and the nerve from the magnitude of the provided intracorporeal stimulus and the magnitude of acceleration of the muscle.

Abstract: A method of determining a change in nerve function attributable to a surgical procedure includes assessing the nerve function via a first, induced mechanomyographic muscle response prior to the surgical procedure, and reassessing the nerve function via a second, induced mechanomyographic muscle response after the surgical procedure. Each mechanomyographic muscle response may be induced through an electrical stimulus provided directly to the nerve of the subject.

Abstract: A neural monitoring system for detecting an artificially-induced mechanical muscle response to a stimulus provided within an intracorporeal treatment area includes a mechanical sensor and a processor in communication with the mechanical sensor. The mechanical sensor is configured to be placed in mechanical communication with the muscle and to generate a mechanomyography output signal corresponding to a sensed mechanical movement of the muscle. The processor is configured to receive the mechanomyography output signal from the mechanical sensor and determine a frequency component of the mechanomyography output signal that has a peak magnitude and to detect the occurrence of an artificially-induced mechanical muscle response therefrom.

Abstract: A neural monitoring system for detecting an artificially-induced mechanical muscle response to an electrical stimulus at a stimulation frequency includes a mechanical sensor and a processor in communication with the mechanical sensor. The mechanical sensor is configured to be placed in mechanical communication with the muscle and to generate a mechanomyography output signal corresponding to a sensed mechanical movement of the muscle. The processor is configured to receive the mechanomyography output signal from the mechanical sensor and determine a frequency component of the mechanomyography output signal that has a peak magnitude and to detect the occurrence of an artificially-induced mechanical muscle response therefrom.

Abstract: A system for detecting the presence of a nerve within a subject includes a stimulator configured to provide a stimulus to a portion of the subject, a sensing device configured to be placed in communication with a muscle of the subject and to generate an output signal corresponding to a monitored parameter of the muscle, the sensing device including a mechanical sensor configured to monitor a mechanical parameter of the muscle, and a receiver configured to receive the output signal from the sensing device and to determine if the output signal corresponds to the stimulus provided by the stimulator.

Abstract: A robotic surgical system for performing a surgical procedure within the body of a subject includes an elongate surgical instrument, a robotic controller configured to control the motion of the distal end portion of the surgical instrument, and a mechanomyography feedback system in communication with the robotic controller. The mechanomyography feedback system includes an elongate sphincter contraction sensor configured to monitor a physical response of a sphincter of the subject and to provide a mechanomyography signal corresponding to the monitored response. Additionally, the feedback system includes a processor configured to receive the mechanomyography signal, to determine if the received signal is indicative of an induced sphincter response, and to provide a control signal to the robotic controller if an induced sphincter response is detected.

Abstract: A neural monitoring system for detecting an induced response of a muscle to a stimulus provided within an intracorporeal treatment area of a human subject includes a mechanical sensor configured to be placed in mechanical communication with the muscle and to generate a mechanomyography output signal corresponding to a sensed mechanical movement of the muscle, and a receiver in communication with the mechanical sensor. The receiver is configured to: receive the mechanomyography output signal from the mechanical sensor; compute a time derivative of the sensed muscle movement from the mechanomyography output signal; compare the computed time derivative to a threshold; and indicate that the sensed mechanical movement of the muscle was induced by the provided intracorporeal stimulus if the computed time derivative exceeds the threshold.

Abstract: A robotic surgical system for performing a surgical procedure within the body of a subject includes an elongate surgical instrument, a robotic controller configured to control the motion of the distal end portion of the surgical instrument, and a mechanomyography feedback system in communication with the robotic controller. The mechanomyography feedback system includes a mechanical sensor configured to monitor a physical motion of a muscle and to provide a mechanomyography signal corresponding to the monitored physical motion. Additionally, the feedback system includes a processor configured to receive the mechanomyography signal, to determine if the received signal is indicative of an induced muscle response, and to provide a control signal to the robotic controller if an induced muscle response is detected.

Abstract: A robotic surgical system for performing a surgical procedure within the body of a subject includes an elongate surgical instrument, a robotic controller configured to control the motion of the distal end portion of the surgical instrument, and a mechanomyography feedback system in communication with the robotic controller. The mechanomyography feedback system includes an elongate sphincter contraction sensor configured to monitor a physical response of a sphincter of the subject and to provide a mechanomyography signal corresponding to the monitored response. Additionally, the feedback system includes a processor configured to receive the mechanomyography signal, to determine if the received signal is indicative of an induced sphincter response, and to provide a control signal to the robotic controller if an induced sphincter response is detected.

Abstract: A method of identifying a change in the health of a nerve during a surgical procedure includes determining a sensitivity of the nerve at a first time, determining a sensitivity of the nerve at a second time, and providing an indication to a user corresponding to a change in the sensitivity of the nerve from the first time to the second time. In each instance, the sensitivity of the nerve is determined by providing an electrical stimulus via an electrode disposed on a distal end portion of an elongate medical instrument, and monitoring a magnitude of a mechanical response of a muscle innervated by the nerve.

Abstract: An elongate sphincter contraction sensor includes an elongate device body configured to be inserted within a sphincter of the subject; and a force sensor in mechanical communication with the elongate device body and configured to provide a mechanomyography output signal in response to a contact force applied against the elongate device body by the sphincter.