In some examples, a medical device is configured to automatically determine a paresthesia threshold or a perception threshold of a patient in a second posture based on the paresthesia threshold or perception threshold of that patient in a first posture. The medical device may deliver an electrical stimulation signal to a patient and determine the paresthesia threshold or perception threshold for the patient in the first posture. The medical device may change the intensity of the electrical signal and receive an indication from the patient that they are experiencing paresthesia or perceiving the electrical stimulation signal. The medical device may then automatically determine a predicted paresthesia threshold or predicted perception threshold for a second posture based on the paresthesia threshold or perception threshold.

The disclosure describes example of subsensory electrical stimulation for providing therapy for incontinence. An implantable medical device (IMD) includes a memory configured to store a set of therapy parameters for subsensory electrical stimulation of a patient. The delivery of the subsensory electrical stimulation results in a therapeutic effect for incontinence therapy at a stimulation intensity that is in range of approximately 50% to 80% of a stimulation intensity at a sensory threshold, and the patient does not perceive delivery of the subsensory electrical stimulation and perceives delivery of stimulation at the sensory threshold. The IMD also includes therapy delivery circuitry configured to deliver the subsensory electrical stimulation based on the stored set of therapy parameters, including cycling the delivery of the subsensory electrical stimulation between an on-cycle and an off-cycle.

Apparatus is provided that includes an extracranial electrode, configured to be placed outside and in electrical contact with a skull of a subject identified as at risk of or suffering from a disease; and a cerebrospinal fluid (CSF) electrode, configured to be implanted in a ventricular system of a brain of the subject. Control circuitry is configured to drive the extracranial and the CSF electrodes to clear a substance from brain parenchyma of the subject into the ventricular system of the brain. Other embodiments are also described.

An example of a system to program a neuromodulator to deliver neuromodulation to a neural target using a plurality of electrodes may comprise a programming control circuit configured to determine target energy allocations for the plurality of electrodes based on at least one target pole to provide a target sub-perception modulation field, and normalize the target sub-perception modulation field, including determine a time domain scaling factor to account for at least one property of a neural target or of a neuromodulation waveform, and apply the time domain scaling factor to the target energy allocations.

A system can utilize interleaving periods or waveforms to stimulate patient tissue and sense signals using the stimulation electrodes. For example, the system can utilize alternating therapeutic periods and sensing periods. As another example, the system can alternate between biphasic waveforms having opposite temporal orders of positive and negative phases. As another example, waveforms that differ in a parameter, such as amplitude or pulse width, can be interleaved to provide different information in the respective sensed signals.

A device for neurostimulation has a number N of electrodes. N is equal to or larger than 3. The device is configured to deliver via each electrode therapeutic electric phases of amplitudes I.sub.1, I.sub.2, . . . I.sub.N, with a frequency f and after each therapeutic electric phase a number of N1 charge balancing electric phases. The charge balancing electric phases of the respective electrode each have a polarity that is opposite the polarity of the preceding therapeutic electric phase of the respective electrode. The device is configured to return for each electrode the current of each therapeutic electric phase in the other N1 electrodes.

A method and external device for providing sub-perception stimulation to a patient via an implantable stimulator device is disclosed. Stimulation parameters for the patient are determined that provide sub-perception stimulation to address a symptom of the patient. A schedule is determined to provide scheduled boluses of stimulation, where each bolus comprises a duration during which stimulation is applied to the patient in accordance with the stimulation parameters, and where the scheduled boluses are separated by off times when no stimulation is provided to the patient. Preferably, the duration of each of the scheduled boluses is 3 minutes or longer, and the duration of each of the off times is 30 minutes or greater. Additional boluses can be provided on demand in addition to the scheduled boluses by selecting an option on the external device, although the provision of such additional boluses may be constrained by a lockout period.

An example of a system to program a neuromodulator to deliver neuromodulation to a neural target using a plurality of electrodes may comprise a programming control circuit configured to determine target energy allocations for the plurality of electrodes based on at least one target pole to provide a target sub-perception modulation field, calibrate a plurality of electrode groups in the plurality of electrodes where each of the plurality of electrode groups is in an electrode configuration and includes an electrode set of at least one electrode from the plurality of electrodes, including for each of the plurality of electrode groups receive a feedback metric to delivery of modulation energy to the neural target, and normalize the target sub-perception modulation field, including determine a space domain scaling factor using the feedback metric to account for actual electrode-tissue coupling, and apply the space domain scaling factor to the target energy allocations.

A device for neurostimulation including an electrode structure for delivering stimulation pulses to a nerve as well as for processing and extracting evoked compound action potentials, wherein the electrode structure comprises at least a first anode, at least a second anode opposing the first anode and a plurality of cathodes arranged between said anodes, wherein said cathodes are asymmetrically arranged with respect to said at least first and second anode to permit evoked compound action potential sensing via the anode electrodes simultaneously with stimulation.

This application is generally related to identifying or otherwise programming one or more cycling parameters for operation of an implantable pulse generator to provide a neurostimulation therapy to a patient using a non-paresthesia stimulation pattern. in some embodiments, the cycling parameter is selected by measuring physiological signals during trial stimulation. In other embodiments, multiple cycling parameters are identified for use by the patient using a patient controller device.