Abstract: A neuromodulation device comprises stimulus electrodes and sense electrodes. A stimulus source provides stimuli to evoke a neural response on a neural pathway. A signal sensed at the sense electrodes includes an evoked neural response. A control unit controls the stimulus source to provide the neural stimulus according to a stimulus intensity parameter; measures an intensity of the evoked response; and completes a feedback loop using the measured intensity and controller parameters to control the stimulus intensity parameter to maintain the measured intensity at a target value. Optimal values of the controller parameters are determined from a representative value of a characteristic of the feedback loop, the representative value having been derived from data of previously programmed patients, and/or the processor is configured to determine optimal values of the one or more controller parameters from a predetermined value of an amplification parameter of the feedback loop.

Abstract: Disclosed is a method of adapting the operation of an implantable device for delivering neurostimulation therapy to a patient. The method comprises: delivering the neurostimulation therapy to electrically excitable tissue of the patient according to at least one therapy parameter; measuring a physiological characteristic of the patient; adjusting the at least one therapy parameter according to a schedule of adjustment and the measured physiological characteristic; and repeating the delivering, measuring, and adjusting.

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: 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 neuromodulation device (100) that includes a plurality of stimulus electrodes, measurement electrodes, a stimulus source and measurement circuitry (128). The device also includes a control unit (116) configured to: control the stimulus source to provide a neural stimulus to a neural pathway (180) according to a stimulus intensity parameter; measure an intensity of the evoked neural response in captured signal windows; determine a feedback variable from the measured intensity of the evoked neural response; implement a feedback loop by using the feedback variable to control the stimulus intensity parameter so as to maintain the feedback variable at a target value; convert (1404) a loop variable of the feedback loop to a representation, where the representation is one of a time-domain representation and a frequency-domain representation; and analyse (1406) the representation to determine a loop stability measure of the feedback loop.

Abstract: Disclosed is an implantable device for controllably delivering a neural stimulus. The device comprises: a plurality of electrodes including one or more stimulus electrodes and one or more sense electrodes; a stimulus source configured to provide a neural stimulus to be delivered via the one or more stimulus electrodes to a neural pathway of a patient in order to evoke a neural response on the neural pathway; measurement circuitry configured to process a signal window sensed at the one or more sense electrodes subsequent to the delivered neural stimulus, the sensed signal window including an evoked neural response; and a control unit.

Abstract: Disclosed is an electrode lead assembly comprising an electrode lead body and a plurality of electrodes arranged along a length of the body. The plurality of electrodes comprising a first group of electrodes and a second group of electrodes, wherein adjacent pairs of electrodes in each group of electrodes have a respective electrode pitch. The first group and the second group of electrodes each comprise at least one electrode configurable as a stimulus electrode for delivering stimulation to a neural target and at least one electrode configurable as a measurement electrode for measuring a response evoked by the delivered stimulation. The first group of electrodes is separated from the second group of electrodes by an electrode-free lead portion, the electrode-free lead portion having a length that is greater than each electrode pitch of the first group of electrodes and greater than each electrode pitch of the second group of electrodes.

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: 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: A neural stimulation system comprising: a neuromodulation device for delivering neural stimuli, and a processor. The neurostimulation device comprises: a plurality of electrodes; a stimulus source to provide neural stimuli to be delivered via the electrodes to a neural tissue to evoke neural responses; measurement circuitry configured to capture signal windows sensed at the electrodes subsequent to respective neural stimuli; and a control unit configured to control the stimulus source to provide each neural stimulus according to a stimulus intensity parameter. The processor is configured to: instruct the control unit to control the stimulus source to sequentially provide a plurality of neural stimuli according to a ramp of stimulus intensity parameter values up to a perceptual marker; receive a captured signal window subsequent to each neural stimulus; detect whether an evoked neural response is present in each signal window; and determine the perceptual marker based on the detecting.

Abstract: Disclosed is an implantable device for lead offset determination, comprising first and second electrode leads. A stimulus is delivered from one lead to tissue, and a signal is sensed from the tissue by the other lead. The sensed signal is processed to produce a measure of a stimulus artefact present in the signal. The stimulus artefact measure is used to produce a measure of an offset between the first electrode lead and the second electrode lead, such as by applying a distance-squared analytical model to measures of stimulus artefact obtained from at least two sense electrodes. And/or, a compound action potential evoked by the stimulus is sensed from neural tissue, a latency of the evoked compound action potential is measured, and a measure of an offset between the first electrode lead and the second electrode lead is produced from the latency.

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: A method for measuring a neural response to a stimulus. Measurement circuitry is settled prior to a stimulus, by connecting a sense electrode to the measurement circuitry to allow the measurement circuitry to settle towards a bio-electrically defined steady state. Charge is recovered on stimulus electrodes by short circuiting the stimulus electrodes to each other. An electrical stimulus is then applied from the stimulus electrodes to neural tissue, while keeping the sense electrode disconnected from the measurement circuitry. After the stimulus, a delay is imposed during which the stimulus electrodes are open circuited and the sense electrode is disconnected from the measurement circuitry and from the stimulus electrodes. After the delay, a neural response signal present at the sense electrode is measured by connecting the sense electrode to the measurement circuitry.

Abstract: A method of applying a neural stimulus with an implanted electrode array involves applying a sequence of stimuli configured to yield a therapeutic effect while suppressing psychophysical side effects. The stimuli sequence is configured such that a first stimulus recruits a portion of the fibre population, and a second stimulus is delivered within the refractory period following the first stimulus and the second stimulus being configured to recruit a further portion of the fibre population. Using an electrode array and suitable relative timing of the stimuli, ascending or descending volleys of evoked responses can be selectively synchronised or desynchronised to give directional control over responses evoked.

Abstract: A method of controlling a neural stimulus by use of feedback. The neural stimulus is applied to a neural pathway in order to give rise to an evoked action potential on the neural pathway. 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 is derived. A feedback loop is completed by using the feedback variable to control the at least one stimulus parameter value. The feedback loop adaptively compensates for changes in a gain of the feedback loop caused by electrode movement relative to the neural pathway.

Abstract: Disclosed is a method of adapting the operation of an implantable device for delivering neurostimulation therapy to a patient. The method comprises: delivering the neurostimulation therapy to electrically excitable tissue of the patient according to at least one therapy parameter; measuring a physiological characteristic of the patient; adjusting the at least one therapy parameter according to a schedule of adjustment and the measured physiological characteristic; and repeating the delivering, measuring, and adjusting.

Abstract: A method of evaluating spinal cord stimulation (SCS), comprising obtaining neural response data generated by a spinal cord stimulator, where the neural response data describes one or more neural signals evoked in the spinal cord of a patient by applying diagnostic stimuli. One or more evoked compound action potentials (ECAPs) associated with the respective one or more neural signals are detected. The one or more detected ECAPs are processed to generate one or more evaluation metrics, and the one or more evaluation metrics are used to generate a confidence score indicating a degree of effectiveness of SCS on the patient.

Abstract: A method for measuring a neural response to a stimulus. Measurement circuitry is settled prior to a stimulus, by connecting a sense electrode to the measurement circuitry to allow the measurement circuitry to settle towards a bio-electrically defined steady state. Charge is recovered on stimulus electrodes by short circuiting the stimulus electrodes to each other. An electrical stimulus is then applied from the stimulus electrodes to neural tissue, while keeping the sense electrode disconnected from the measurement circuitry. After the stimulus, a delay is imposed during which the stimulus electrodes are open circuited and the sense electrode is disconnected from the measurement circuitry and from the stimulus electrodes. After the delay, a neural response signal present at the sense electrode is measured by connecting the sense electrode to the measurement circuitry.

Abstract: Disclosed is an automated programming system for a neuromodulation device that is configured to assist a clinician to efficiently program the neuromodulation device for a particular patient. In particular, the assisted programming system comprises a stimulation user interface control that is configured to cause the intensity of the neural stimulus to ramp up with time as long as the patient continues to interact with the control. The value of stimulus intensity at which the patient ceases to interact with the control is recorded as a significant perceptual marker upon which subsequent steps in the assisted programming workflow are based. This user interface design takes advantage of the human withdrawal reflex, whereby the patient is likely to instinctively release the button upon receiving uncomfortable stimulation. The design therefore minimises the training burden placed on the patient in using the assisted programming system.

Abstract: A method for measuring a neural response to a stimulus. Measurement circuitry is settled prior to a stimulus, by connecting a sense electrode to the measurement circuitry to allow the measurement circuitry to settle towards a bio-electrically defined steady state. Charge is recovered on stimulus electrodes by short circuiting the stimulus electrodes to each other. An electrical stimulus is then applied from the stimulus electrodes to neural tissue, while keeping the sense electrode disconnected from the measurement circuitry. After the stimulus, a delay is imposed during which the stimulus electrodes are open circuited and the sense electrode is disconnected from the measurement circuitry and from the stimulus electrodes. After the delay, a neural response signal present at the sense electrode is measured by connecting the sense electrode to the measurement circuitry.