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: 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: 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: 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 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: 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: 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 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 response parameter indicative of the measured response, in response to the response parameter being less than a first threshold, setting the stimulus intensity parameter to a desired stimulus intensity level; and in response to the response parameter being greater than a second threshold, adjust the stimulus intensity parameter according to a feedback variable derived from the measured response.

Abstract: An implantable device for controllably stimulating a neural target. The device configured to electrically couple to a paddle electrode assembly, the paddle electrode assembly comprising a plurality of electrodes including a first group of one or more electrodes arranged on a ventral surface of a paddle body, and a second group of one or more electrodes arranged on a dorsal surface of the paddle body. The implantable device comprises stimulation circuitry, configured to provide stimulation energy to one or more electrodes of the paddle electrode assembly, measurement circuitry, configured to measure a response evoked from the neural target by the stimulation energy and sensed by one or more electrodes of the paddle electrode assembly, and an electrode selection module.

Abstract: This disclosure relates to a device for applying a neural stimulus. A battery supplies electrical energy at a battery voltage and an electrode applies the electrical energy to neural tissue. A circuit measures the nervous response of the tissue and a voltage converter receives the electrical energy from the battery and controls a voltage applied to the electrode based on the measured nervous response of the tissue. This direct voltage control is energy efficient because losses across a typical current mirror are avoided. Further, the control based on the measured nervous response leads to automatic compensation of impedance variation due to in-growth or change in posture. As a result, the stimulation results in a desired neural response.

Abstract: A device for recording evoked neural responses, comprising one or more stimulus electrodes and one or more sense electrodes. The device has a stimulus source for providing a stimulus to be delivered from the stimulus electrodes to a neural pathway in order to give rise to an evoked action potential on the neural pathway. The device has measurement circuitry for recording a neural compound action potential signal sensed at the sense electrodes. Crosstalk cancellation circuitry is configured to produce a stimulus crosstalk cancellation signal, and is configured to inject the stimulus crosstalk cancellation signal into the measurement circuitry. The stimulus crosstalk cancellation signal is configured to cancel a stimulus crosstalk voltage arising upon the one or more sense electrodes as a result of delivery of the stimulus.

Abstract: A lead (1) for an active implantable medical device comprising: an elongated, biocompatible, electrically non-conductive body (3); a plurality of electrically conductive filaments (5) inside the elongated body (3) to electrically connect electrical connectors (6) to corresponding electrodes (8); and at least one elongated decoy conductor (10) inside the elongated body (3) to electromagnetically couple with the plurality of electrically conductive filaments (5), wherein the at least one decoy conductor (10) has a higher electrical resistance than the plurality of electrical conductive filaments (5) to dissipate energy from currents induced by radio frequencies.

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: Measuring a neural response to a stimulus comprises applying an electrical stimulus, then imposing a delay during which the stimulus electrodes are open circuited. During the delay, a neural response signal present at sense electrodes is measured with a measurement amplifier, while ensuring that an impedance between the sense electrodes is sufficiently large that a voltage arising on the sense electrode tissue interface in response to the stimulus is constrained to a level which permits assessment of the neural response voltage seen at the sense electrode. For example the input impedance to the measurement amplifier (ZIN) can be, where ZC is the sense electrode(s) constant phase element impedance, Vs1?Vs2 is the differential voltage arising on the sense electrode tissue interface, and VE is the neural response voltage seen at the sense electrode.

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: 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: 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: Measuring a neural response to a stimulus comprises applying an electrical stimulus, then imposing a delay during which the stimulus electrodes are open circuited. During the delay, a neural response signal present at sense electrodes is measured with a measurement amplifier, while ensuring that an impedance between the sense electrodes is sufficiently large that a voltage arising on the sense electrode tissue interface in response to the stimulus is constrained to a level which permits assessment of the neural response voltage seen at the sense electrode. For example the input impedance to the measurement amplifier (ZIN) can be Z IN > Z C ? ( V S ? ? 1 - V S ? ? 2 ) V E , where ZC is the sense electrode(s) constant phase element impedance, Vs1?Vs2 is the differential voltage arising on the sense electrode tissue interface, and VE is the neural response voltage seen at the sense electrode.