Boston Scientific Neuromodulation Corporation

Kiran K Gururaj

Goran Nils Marnfeldt

David Michael Wagenbach

Pujitha Weerakoon

Philip Leonard Weiss

Joseph M Bocek

Matthew Lee McDonald

Emanuel Feldman

Ross Daniel Venook

Rafael Carbunaru

Gaurav Gupta

Jordi Parramon

Rosana Esteller

Tianhe Zhang

Mizanur Rahman

Pranjali Borkar

Salomo Siilas Murtonen

Salomo Murtonen

David M Wagenbach

Matthew L Mcdonald

Techniques for sensing neural responses such as Evoked Compound Action Potentials (ECAPs) in an implantable stimulator device are disclosed. A first therapeutic pulse phase is followed by a charge recovery phase that includes at least one high-impedance passive charge recovery duration. The ECAP is sensed during the high-impedance passive charge recovery duration. The time period of the passive charge recovery is lengthened and the high-impedance passive recharge duration entirely overlaps the ECAP (i.e., the neural response duration) at the sensing electrode.

Neural sensing in an implantable stimulator device during passive charge recovery

Methods and systems for providing neuromodulation therapy are disclosed. The methods and systems are configured to sense an evoked neural response and use the evoked neural response as feedback for providing neuromodulation therapy. Methods of reducing stimulation artifacts that obscure the sensed evoked neural response are disclosed. The methods of artifact reduction include recording a stimulation artifact in the absence of an evoked neural response, aligning and scaling the stimulation artifact with respect to the obscured signal, and subtracting the aligned and scaled artifact from the obscured signal.

Artifact reduction in a sensed neural response

Waveforms for a stimulator device, and methods and circuitry for generating them, are disclosed having high- and low-frequency aspects. The waveforms comprise a sequence of pulses issued at a low frequency which each pulse comprising first and second charge-balanced phases. One or both of the phases comprises a plurality a monophasic sub-phase pulses issued at a high frequency in which the sub-phase pulses are separated by gaps. The current during the gaps in a phase can be zero, or can comprise a non-zero current of the same polarity as the sub-phase pulses issued during that phase. The disclosed waveforms provide benefits of high frequency stimulation such as the promotion of paresthesia free, sub-threshold stimulation, but without drawbacks inherent in using high-frequency biphasic pulses.

Stimulation waveforms with high- and low-frequency aspects in an implantable stimulator device

Techniques for sensing neural responses such as Evoked Compound Action Potentials (ECAPs) in an implantable stimulator device are disclosed. A first therapeutic pulse phase is followed by a second pulse phase, which phases may be of opposite polarities to assist with active charge recovery. The second pulse phase is formed so as to overlap in time with the arrival of the ECAP at a sensing electrode, which second phase may generally be longer and of a lower amplitude. In so doing, a stimulation artifact formed in a patient's tissue is rendered constant, and of a smaller amplitude, when the ECAP is sensed at the sensing electrode, which eases sensing by a sense amp circuit. Passive charge recovery may follow the second phase, which will not interfere with ECAP sensing that has already occurred.

Neural sensing in an implantable stimulator device during the provision of active stimulation

An implantable pulse generator (IPG) is disclosed having an improved ability to steer anodic and cathodic currents between the IPG's electrodes. Each electrode node has at least one PDAC/NDAC pair to source/sink or sink/source a stimulation current to an associated electrode node. Each PDAC and NDAC receives a current with a magnitude indicative of a total anodic and cathodic current, and data indicative of a percentage of that total that each PDAC and NDAC will produce in the patient's tissue at any given time, which activates a number of branches in each PDAC or NDAC. Each PDAC and NDAC may also receive one or more resolution control signals specifying an increment by which the stimulation current may be adjusted at each electrode. The current received by each PDAC and NDAC is generated by a master DAC, and is preferably distributed to the PDACs and NDACs by distribution circuitry.

Current generation architecture for an implantable stimulator device including distributor circuitry for sending an amplitude-scaled current to digital-to-analog converters at the electrodes

Digital-to-analog converter (DAC) circuitry for providing currents at electrodes of an Implantable Pulse Generator (IPG) is disclosed. The DAC circuitry includes at least one PDAC for sourcing current to the electrodes, and at least one NDAC for sinking current from the electrodes. The PDACs are powered with power supplies VH (the compliance voltage) and Vssh in a high power domain, and the NDACs are powered with power supplies Vcc and ground in a low power domain. VH may change during IPG operation, and Vssh preferably also changes with a fixed difference with respect to VH. Digital control signals to the PDACs are formed (and possibly converted into) the high power domain, and transistors used to build the PDACs are biased in the high power domain, and thus may also change with VH. This permits transistors in the PDACs and NDACs to be made from normal low-voltage logic transistors.

Biasing of a current generation architecture for an implantable medical device

Improved circuitry for measuring analog values in an implantable pulse generator is disclosed. The measurement circuitry executes instructions that define the timing and parameters of measurements to be taken. The instructions include instructions that are responsive to different types of triggers issued by different pulse definition circuits, which pulse definition circuits generate different stimulation waveforms at different groups of electrodes. The measurement circuitry is configurable to update the groups of electrodes used to deliver stimulation.

Measurement circuitry for measuring analog values in an implantable pulse generator

Methods, medical devices, and magnetic resonance imaging (MRI) systems are provided. A patient implanted with a medical device is exposed to a time-varying magnetic field having a signature, thereby inducing mechanical vibrations in at least one component of the medical device. A vibrational characteristic of the mechanical vibrations induced in the component(s) is detected. The vibrational characteristic is analyzed, and the signature of the magnetic field is identified based on the analyzed vibrational characteristic. The medical device is automatically switched from a first operational mode to a second operational mode when the signature is identified.

Systems and method for automatically detecting an MRI environment for patient implanted with medical device

An active implantable medical device (AIMD) for use with a medical lead carrying at least one lead electrode. The AIMD comprises interior electronic circuitry configured for performing a medical function via the medical lead, an electrically conductive case containing the interior electronic circuitry, at least one electrical terminal configured for electrically coupling the electronic circuitry respectively to the lead electrode(s), and an inductive element coupled in series between the electrical terminal(s) and the case. The inductive element is configured for hindering the shunting of electrical current from the at least one electrical terminal to the case that has been induced by electromagnetic interference (EMI) impinging on the medical lead.

Implantable medical device having electromagnetic interference filter device to reduce pocket tissue heating

A neurostimulation device capable of being placed between an active stimulation state and an inactive stimulation state and method of using same. The neurostimulation device comprises a plurality of electrical terminals configured for being respectively coupled to a plurality of stimulation electrodes, a first solid-state switching device coupled to a first one of the electrical terminals, a variable power source coupled to the first switching device, and a controller configured for, when the neurostimulation device is in the inactive stimulation state, prompting the variable power source to selectively output a relatively low voltage to place the first switching device into a first open state and a relatively high voltage to place the first switching device into a second open state.

Growing community of inventors

Valencia, CA, United States of America

Kiran K Gururaj