An implant system includes an electrode portion comprising plural electrodes to perform nerve stimulation and nerve sensing, an impedance controller configured to selectively connect the plural electrodes between a stimulator to perform nerve stimulation and a sensor to perform nerve sensing based on a control signal, and set an impedance of each of the plural electrodes, and a processor configured to control a contact impedance by the plural electrodes by generating the control signal to control at least one of plural switches connected respectively to the plural electrodes, or variable resistors connected respectively to the plural electrodes, based on at least one of a selectively set purpose of the plural electrodes or a position of an electrode to which nerve stimulation is to be provided.

Systems and methods for providing stimulation and neural response sensing in an implantable stimulation device are disclosed. A neural response database records baseline neural response information from one or more sensing electrodes for a given pole configuration that provides stimulation to a patient. The stimulation device can then take neural response measurements at the sensing electrode(s) and the system (possibly with the assistance of an external device in communication with the stimulation device) can compare the neural response measurements with the baselines. If they differ, as they might if the electrode array has moved in the patient's tissue, an algorithm can be used to move the position of the pole configuration in the electrode array to cause the neural response measurements to equal, or at least come closer to, the neural response baselines.

A system includes processing circuitry configured to determine, for each respective electrode of a plurality of electrodes, a score based on a ratio of an electrical efficiency for the respective electrode to a therapeutic window for the respective electrodes. The processing circuitry is further configured to determine, based on the score of each respective electrode, a ranking of the plurality of electrodes, and to select, based on the ranking, a subset of the plurality of electrodes for delivery of electrical stimulation therapy.

A system for estimating a volume of activation around an implanted electrical stimulation lead for a set of stimulation parameters includes a display; and a processor coupled to the display and configured to: receive a set of stimulation parameters including a stimulation amplitude and a selection of one of more electrodes of the implanted electrical stimulation lead for delivery of the stimulation amplitude; determine an estimate of the volume of activation based on the set of stimulation parameters using the stimulation amplitude and a database including a plurality of planar distributions of stimulation threshold values and a map relating the planar distributions to spatial locations based on the one or more electrodes of the implanted electrical stimulation lead selected for delivery of the stimulation amplitude; and output on the display a graphical representation of the estimate of the volume of activation.

Methods and systems can facilitate visualizing cathodic and anodic stimulation separately. Alternately, the methods and systems may separately visualize stimulation of different neural elements, such as nerve fibers and neural cells. These methods and systems can further facilitate programming an electrical stimulation system for stimulating patient tissue.

Disclosed are methods and systems for treating epilepsy by stimulating a main trunk of a vagus nerve, or a left vagus nerve, when the patient has had no seizure or a seizure that is not characterized by cardiac changes such as an increase in heart rate, and stimulating a cardiac branch of a vagus nerve, or a right vagus nerve, when the patient has had a seizure characterized by cardiac changes such as a heart rate increase.

An automated method of controlling neural stimulation. A neural stimulus is applied to a neural pathway in order to give rise to an evoked action potential on the neural pathway, and the stimulus is defined by at least one stimulus parameter. A neural compound action potential response evoked by the stimulus is measured. From the measured evoked response a feedback variable such as observed ECAP voltage (V) is derived. A feedback loop is completed by using the feedback variable to control the at least one stimulus parameter value for a future stimulus. The method adaptively compensates for changes in a gain of the feedback loop caused by electrode movement relative to the neural pathway. A compensating transfer function is applied to the feedback variable, the compensating transfer function being configured to compensate for both (i) a distance-dependent transfer function of stimulation, and (ii) a distance dependent transfer function of measurement which is distinct from (i).

A system and method for automatically implementing a therapy for treating sleep disordered breathing.

An example system includes a lead including a first electrode disposed at a first level, a second electrode disposed at a second level, a first group of segmented electrodes disposed at a third level, and a second group of segmented electrodes disposed at a fourth level. The example system also includes a medical device configured to deliver symmetrical electrical stimulation to a patient via the first group of segmented electrodes and the second group of segmented electrodes and sense a response to the stimulation via the first electrode and the second electrode.

A method for optimizing stimulation for a patient having a stimulator device such as a Deep Brain Stimulation (DBS) device is disclosed. Test stimulation is provided at initial combinations of lead positions and values of a stimulation parameter such as amplitude, neural potentials are measured for each combination, and a neural response score is determined using the measured neural potentials. A next combination of position and a value of the stimulation parameter to test is determined using the neural response scores. This process repeats iteratively until a stopping criterium is met. The neural response scores and then used determine optimal therapeutic stimulation for the patient. Neural response measurements can also be used to exclude certain positions or stimulation values during subsequent optimization testing.