Abstract: An implantable device for estimating neural recruitment arising from a stimulus, has a plurality of electrodes. A stimulus source provides stimuli to be delivered from the electrodes to neural tissue. Measurement circuitry obtains a measurement of a neural signal sensed at the electrodes. A control unit is configured to control application of a selected stimulus to neural tissue using the stimulus electrodes; and after the selected neural stimulus, apply a probe stimulus having a short pulse width. A remnant neural response evoked by the probe stimulus is measured; and the control unit estimates from the remnant neural response a neural recruitment caused by the selected neural stimulus.

Abstract: Neurostimulation of a mixed nerve comprising a plurality of nerve fibre types. An implantable electrode array comprising a plurality of electrodes is positioned proximal to the mixed nerve. An electrical stimulus is delivered from at least one nominal stimulus electrode of the implantable electrode array, in accordance with a set of stimulus parameters. A recording of the electrophysiological response evoked by the electrical stimulus is obtained from at least one nominal recording electrode of the implantable electrode array. The recording is analysed by assessing one or more selected characteristics of the recording, and from the observed selected characteristics a level of recruitment of one or more fibre types recruited by the electrical stimulus is identified. The stimulus parameters are refined in a manner to effect selective recruitment of one or more fibre types relative to other fibre types of the mixed nerve.

Abstract: An implantable device for controlling electrical conditions of body tissue. A feedback sense electrode and a compensation electrode are positioned proximal to the tissue to make electrical contact with the tissue. A feedback amplifier is referenced to ground, and takes as an input a feedback signal from the feedback sense electrode. The output of the feedback amplifier is connected to the compensation electrode. The feedback amplifier thus drives the neural tissue via the compensation electrode in a feedback arrangement which seeks to drive the feedback signal to ground, or other desired electrical value.

Abstract: Estimating a nerve-to-electrode distance involves applying a stimulus from a stimulus electrode to a nerve. Neural measurements of at least one evoked compound action potential are obtained, and processed in order to estimate an originating state of stimulation exhibiting at least one characteristic defined by a single fibre size. A single fibre model is then applied to produce a measure of the nerve-to-electrode distance. Also provided for is estimation of a distribution of recruited fibres. Measurements of a compound action potential are obtained from sense electrodes spaced apart along a neural pathway. A conduction velocity of the compound action potential is determined from the latency between the measurements. From the conduction velocity a dominant recruited fibre diameter is determined. A rate of dispersion of the compound action potential between the sense electrodes is determined. From the rate of dispersion a distribution of diameters of the recruited fibre population is determined.

Abstract: A method for processing a neural measurement obtained in the presence of artifact, in order to detect whether a neural response is present in the neural measurement. A neural measurement is obtained from one or more sense electrodes. The neural measurement is correlated against a filter template, the filter template comprising at least three half cycles of an alternating waveform, amplitude modulated by a window. From an output of the correlating, it is determined whether a neural response is present in the neural measurement.

Abstract: Recording evoked neural responses comprises delivering a stimulus from one or more stimulus electrodes to a neural pathway in order to give rise to an evoked compound action potential (ECAP) on the neural pathway. And, recording with measurement circuitry, during delivery of at least part of the stimulus, a neural compound action potential signal sensed at one or more sense electrodes. And, processing the recording of the neural compound action potential signal to determine at least one characteristic of the ECAP. At least one characteristic of the stimulus is then defined based on the determined at least one characteristic of the ECAP.

Abstract: Disclosed is a neurostimulation system comprising: a neuromodulation device for controllably delivering neural stimuli; a headset configured to be worn by the patient and to display images of a virtual object to the patient; one or more sensors configured to perceive a gesture of the patient; and an external computing device. The neuromodulation device comprises: a plurality of implantable electrodes; a stimulus source configured to deliver neural stimuli via selected ones of the implantable electrodes to a neural pathway of a patient; and a control unit configured to control the stimulus source to deliver each neural stimulus according to one or more stimulus parameters. The external computing device comprises a processor in communication with the neuromodulation device, the headset, and the one or more sensors.

Abstract: An implantable device comprising: stimulus electrodes and measurement electrodes; a stimulus source to provide a neural stimulus to be delivered to a neural pathway of a patient to evoke a neural response; measurement circuitry configured to capture a signal window sensed on the neural pathway; and a control unit configured to implement closed-loop neurostimulation therapy by: controlling the stimulus source to provide the neural stimulus according to a stimulus intensity parameter; measuring a characteristic of the signal window; computing a feedback variable from an intensity of an evoked neural response in the signal window; adjusting the stimulus intensity parameter using the feedback variable; and repeating the controlling, measuring, computing, and adjusting to maintain the feedback variable at a target, thereby obtaining multiple measured intensities of neural responses; and computing one or more quantitative indicators of efficacy of the closed-loop neurostimulation therapy using the measured characte

Abstract: A method for determining a desired location at which to apply a neural therapy. An array of electrodes is positioned proximal to neural tissue. A stimulus is applied from the array which evokes a neural compound action potential response in the neural tissue proximal to the array. A plurality of electrodes of the array simultaneously obtain respective measurements of the neural compound action potential response. From the measurements of the neural compound action potential response a desired location for a neural therapy is determined.

Abstract: A method of controlling a neural stimulus, the neural stimulus being defined by at least one stimulus intensity parameter. The method comprises generating a stimulus intensity parameter to control a stimulator that generates a stimulus current for application to a tissue, measuring a response of the tissue, evoked by the stimulus current, determining a forward adjustment parameter as a function of the stimulus intensity parameter, determining a feedback parameter derived from the measured response and the forward adjustment parameter and adjusting the stimulus intensity parameter according to the feedback parameter.

Abstract: A neural stimulus comprises at least three stimulus components, each comprising at least one of a temporal stimulus phase and a spatial stimulus pole. A first stimulus component delivers a first charge which is unequal to a third charge delivered by a third stimulus component, and the first charge and third charge are selected so as to give rise to reduced artefact at recording electrodes. In turn this may be exploited to independently control a correlation delay of a vector detector and an artefact vector to be non-parallel or orthogonal.

Abstract: A method for determining a desired location at which to apply a neural therapy. An array of electrodes is positioned proximal to neural tissue. A stimulus is applied from the array which evokes a neural compound action potential response in the neural tissue proximal to the array. A plurality of electrodes of the array simultaneously obtain respective measurements of the neural compound action potential response. From the measurements of the neural compound action potential response a desired location for a neural therapy is determined.

Abstract: Applying therapeutic neural stimuli involves monitoring for at least one of sensory input and movement of a user. In response to detection of sensory input or user movement, an increased stimulus dosage is delivered within a period of time corresponding to a duration of time for which the detected sensory input or user movement gives rise to masking, the increased stimulus dosage being configured to give rise to increased neural recruitment.

Abstract: There is provided a method and implantable device for controlling a neural stimulus, the neural stimulus being defined by an artefact mitigation status. The method comprises generating a first neural stimulus for delivery to neural tissue, sensing a first signal subsequent to the first neural stimulus, generating a second neural stimulus for delivery to the neural tissue, and sensing a second signal subsequent to the second neural stimulus. The method further comprises determining an artefact mitigation measure (AMM) effect level based on the first sensed signal and the second sensed signal, and setting, in response to comparing the AMM effect level with an AMM effect threshold, the artefact mitigation status of a third neural stimulus to active.

Abstract: Controlling a neural stimulus comprises applying the neural stimulus to a neural pathway in order to give rise to an evoked action potential on the neural pathway, the stimulus being defined by at least one stimulus parameter. A neural compound action potential response evoked by the stimulus is measured, and from the measured evoked response a feedback variable is derived. Loop backoff behaviour is adjusted by applying a non-identity function to the feedback variable to produce a revised feedback variable, and completing a feedback loop by using the revised feedback variable to control the at least one stimulus parameter so as to maintain the feedback variable at a setpoint. Additionally, or alternatively, loop gain can be adjusted in response to a change in the loop setpoint, and/or a logarithm of the stimulus parameter can be controlled.

Abstract: An implantable device for delivering closed-loop neural stimulation therapy. The device comprises: a plurality of electrodes; a stimulus source to provide neural stimuli via the electrodes to a neural pathway; measurement circuitry to process signals sensed at the electrodes; and a control unit. The control unit is configured to: control the stimulus source to provide a first neural stimulus according to a first stimulus parameter; measure an intensity of a neural response evoked by the first stimulus; compute a feedback variable from the neural response; adjust the first stimulus parameter; repeat the control, measure, compute and adjust to maintain the feedback variable at a target response intensity; control the stimulus source to provide, interleaved with the first neural stimuli, a plurality of second neural stimuli according to respective second stimulus parameters; and monitor the therapy by analysing the sensed signals subsequent to each second neural stimulus.

Abstract: An implantable neural stimulation device is provided, comprising a body containing stimulation electronics, and a battery to provide stimulation energy, a lid, coupled to the body, the lid configured to at least partially seal the body and a header coupled to the body of the device. The header comprises a contact assembly electrically coupled to the stimulation electronics via at least one feedthrough wire extending through the lid, the contact assembly configured to connect to a stimulation lead to deliver the stimulation energy from the battery under control by the stimulation electronics, a charge coil configured to charge the battery, and a support component configured to support the charge coil. The support component is supported in position by the contact assembly.

Abstract: Disclosed is a method of computing a probability distribution of the suitability of measurement electrode configurations for a neuromodulation device. The method comprises: computing the probability distribution of suitability of measurement electrode configurations from: a predetermined stimulus program vector of the neuromodulation device; and prior patient data. Also disclosed is an automated method of setting a measurement electrode configuration for a neuromodulation device configured to deliver a neural stimulus to a neural pathway of a patient.

Abstract: An implantable pulse generator device (110) comprising a processor (117) configured to: receive, in a charging mode, electromagnetic radiation (106) from a charging device (102) wherein the electromagnetic radiation (106) transfers energy to the implantable device (110) to charge an energy storage device (104); measure, in a measurement mode, an electrical field parameter signal representing a neural response; and selectively transition between the charging mode and the measurement mode, such that the implantable device (110) does not receive electromagnetic radiation (106) from the charging device (102) during the measurement of the electrical field parameter signal.

Abstract: A method of surgically positioning an electrode array at a desired implantation location relative to a nerve. A temporary probe electrode is temporarily positioned adjacent to the nerve and at a location which is caudorostrally separate to the desired implantation location of the electrode array. The implanted position of the probe electrode is temporarily fixed relative to the nerve. During implantation of the electrode array, electrical stimuli are applied from one of the temporarily fixed probe electrode and the electrode array, to evoke compound action potentials on the nerve. Compound action potentials evoked by the stimuli are sensed from at least one electrode of the other of the temporarily fixed probe electrode and the electrode array. From the sensed compound action potentials a position of the electrode array relative to the nerve is determined.