A neurostimulation system and method of blocking a neural axon. Time-varying electrical energy is conveyed to a blocking site on the neural axon for an initial phase. The conveyed electrical energy has an amplitude and frequency during the initial phase sufficient to block action potentials from propagating along the neural axon from a location proximal to the blocking site to a location distal to the blocking site. The time-varying electrical energy is conveyed to the blocking site on the neural axon for a subsequent phase contiguous with the initial phase. The conveyed electrical energy has a decreased amplitude and a frequency during the subsequent phase sufficient to maintain blocking of the action potentials along the neural axon from the location proximal to the blocking site to the location distal to the blocking site.

One aspect of the present disclosure relates to a system that can modulate the intensity of a neural stimulation signal over time. A pulse generator can be configured to generate a stimulation signal for application to neural tissue of an individual and modulate a parameter related to intensity of a pattern of pulses of the stimulation signal over time. An electrode can be coupled to the pulse generator and configured to apply the stimulation signal to the neural tissue. A population of axons in the neural tissue can be recruited with each pulse of the stimulation signal.

Systems and methods for stimulation of neurological tissue generate stimulation trains with temporal patterns of stimulation, in which the interval between electrical pulses (the inter-pulse intervals) changes or varies over time. Compared to conventional continuous, high rate pulse trains having regular (i.e., constant) inter-pulse intervals, the non-regular (i.e., not constant) pulse patterns or trains that embody features of the invention provide a lower average frequency.

Described here are devices, systems, and methods for treating one or more conditions (such as dry eye) or improving ocular health by providing stimulation to nasal or sinus tissue. Generally, the devices may be handheld or implantable. In some variations, the handheld devices may have a stimulator body and a stimulator probe having one or more nasal insertion prongs. When the devices and systems are used to treat dry eye, nasal or sinus tissue may be stimulated to increase tear production, reduce the symptoms of dry eye, and/or improve ocular surface health.

Devices and methods provide for the sensing of physiological signals by providing a stimulation waveform that includes a stimulation pulse followed by an active recharge pulse to clear the charge in capacitors within the stimulation path. The active recharge pulse is followed by a period of passive recharge and then a period of no recharge. Non-neurological sources of artifacts within the sensed physiological signal may be handled by providing a brief period of passive recharge followed by a lengthy period of no recharge, which is made possible by the use of the active recharge pulse prior to the passive recharge. The period of no recharge removes any low impedance path to ground from the stimulation electrodes, which allows an amplifier of the sensing circuit to provide common mode rejection of non-neurological signals, such as cardiac signals, present at the sensing electrodes.

An example of a system for delivering neurostimulation energy may include a stimulation control circuit to control the delivery of the neurostimulation energy according to each of stimulation test patterns. The stimulation control circuit may include a sensing input configured to receive an electrospinogram (ESG) signal recording electrical activity from the spinal cord, a measurement circuit configured to determine one or more response parameters for each test pattern using the received ESG signal, and a selection circuit configured to select a neurostimulation therapy pattern from the stimulation test patterns based on the response parameter(s) and one or more selection criteria. The electrical activity includes responses to the delivered neurostimulation energy, and the response parameter(s) are each indicative of one or more characteristics of the responses. The selection may include selecting a type of stimulation waveform from multiple types of stimulation waveform in the stimulation test patterns.

This invention relates to devices, methods and substances for use in the treatment of hypertension and/or elevated blood pressure in a subject.

System and methods are disclosed to automatically set or update physiological thresholds such as perception threshold (pth) and discomfort thresholds (dth) in an implantable stimulator system. The system monitors neural responses such as ECAPs resulting from stimulation provided to the patient. Extracted neural thresholds (ENTs) are determined, which can comprise a smallest stimulation amplitude at which a neural response can be reliably detected. A correlation between ENTs and physiological thresholds such as pth and dth is used to allow the physiological thresholds to be estimated and updated using the measured ENT values.

Devices, systems, and techniques are described for identifying stimulation parameter values based on electrical stimulation that induces dyskinesia for the patient. For example, a method may include controlling, by processing circuitry, a medical device to deliver electrical stimulation to a portion of a brain of a patient, receiving, by the processing circuitry, information representative of an electrical signal sensed from the brain after delivery of the electrical stimulation, determining, by the processing circuitry and from the information representative of the electrical signal, a peak in a spectral power of the electrical signal at a second frequency lower than a first frequency of the electrical stimulation, and responsive to determining the peak in the spectral power of the electrical signal at the second frequency, performing, by the processing circuitry, an action.

Various embodiments concern delivering electrical stimulation to the brain at a plurality of different levels of a stimulation parameter and sensing a bioelectrical response of the brain to delivery of the electrical stimulation for each of the plurality of different levels of the stimulation parameter. A suppression window of the stimulation parameter can be identified as having a suppression threshold as a lower boundary and an after-discharge threshold as an upper boundary based on the sensed bioelectrical responses. A therapy level of the stimulation parameter can be set for therapy delivery based on the suppression window. The therapy level of the stimulation parameter may be set closer to the suppression threshold than the after-discharge threshold within the suppression window. Data for hippocampal stimulation demonstrating a suppression window is presented.