# US 11,998,745 B2 · Artifact reduction in a sensed neural response > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,998,745 B2 - Document ID: US11998745B2 - Status: Granted - Kind: B2 - Application number: 17/647,905 - Filed: 2022-01-13 - Published: 2022-05-05 - Granted: 2024-06-04 - Earliest claimed: 2018-06-01 - Assignees: Boston Scientific Neuromodulation Corporation - Applicants: Boston Scientific Neuromodulation Corporation - Inventors: Rosana Esteller; Pranjali Borkar; Tianhe Zhang; Kiran K. Gururaj - Web page: https://patentgrep.com/patent/US11998745B2 ## CPC - A61N 1/36135: {using physiological parameters} - A61B 5/24: Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof - A61B 5/7217: {of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker} - A61N 1/36014: {External stimulators, e.g. with patch electrodes (external pacemakers A61N1/3625)} - A61N 1/36062: {Spinal stimulation} - A61N 1/36175: {Pulse width or duty cycle} - A61B 5/407: {Evaluating the spinal cord (for locating the epidural space A61B5/4896)} - A61B 5/4836: {Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence)} - A61B 5/7246: {using correlation, e.g. template matching or determination of similarity} - A61N 1/36125: {Details of circuitry or electric components} - A61N 1/36164: {Sub-threshold or non-excitatory signals (non-excitatory signals to the heart A61N1/3628)} - A61N: ELECTROTHERAPY; MAGNETOTHERAPY; RADIATION THERAPY; ULTRASOUND THERAPY (measurement of bioelectric currents A61B; surgical instruments, devices or methods for transferring non-mechanical forms of energy to or from the body A61B18/00; anaesthetic apparatus in general A61M; incandescent lamps H01K; infrared radiators for heating H05B) - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract 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. ## Claims ### Claim 1 A neuromodulation system for providing electrical stimulation to a patient's spinal cord using one or more electrode leads implantable in the patient's spinal column, wherein each electrode lead comprises a plurality of electrodes, the system comprising: control circuitry configured to: cause a first one or more of the electrodes to issue a first stimulation waveform to the patient's spinal cord tissue, wherein the first stimulation waveform has an amplitude configured to evoke a neural response in the patient's spinal cord and to cause a first stimulation artifact; cause a second one or more of the electrodes to record a first signal in response to the first stimulation, wherein the first signal comprises the neural response and the first stimulation artifact; cause the first one or more electrodes to issue a second stimulation waveform to the patient's spinal cord tissue, wherein the second stimulation waveform has an amplitude configured to cause a second stimulation artifact and not to evoke a neural response in the patient's spinal cord; cause the second one or more electrodes to record a second signal in response to the second stimulation, wherein the second signal comprises the second stimulation artifact; align the first and second signals such that the second stimulation artifact is aligned with the first stimulation artifact; scale the second signal with respect to the first signal; and subtract the second signal from the first signal to yield a third signal that comprises the first neural response and stimulation artifact that is smaller than the first stimulation artifact. ### Claim 2 (depends on 1) The system of claim 1, wherein aligning the first and second signals comprises cross-correlating the first and second signals. ### Claim 3 (depends on 1) The system of claim 1, wherein the control circuitry is further configured to determine a beginning and end of the stimulation artifact. ### Claim 4 (depends on 3) The system of claim 3, wherein in determining a beginning and end of the stimulation artifact comprises using inverse stimulation polarity. ### Claim 5 (depends on 1) The system of claim 1, wherein the control circuitry is control circuitry of an implantable pulse generator (IPG) or of an external trial stimulator (ETS). ### Claim 6 (depends on 1) The system of claim 1, wherein the control circuitry is control circuitry of an external device. ### Claim 7 (depends on 1) The system of claim 1, wherein the control circuitry is further configured to determine one or more features of the first evoked neural response. ### Claim 8 (depends on 7) The system of claim 7, wherein the control circuitry is further configured to alter the first stimulation waveform based on the determined one or more features of the first evoked neural response. ### Claim 9 A method of measuring an evoked neural response using one or more electrode leads implantable in the patient's spinal column, wherein each electrode lead comprises a plurality of electrodes, the method comprising: using a first one or more of the electrodes to issue a first stimulation waveform to the patient's spinal cord tissue, wherein the first stimulation waveform has an amplitude configured to evoke a neural response in the patient's spinal cord and to cause a first stimulation artifact; using a second one or more of the electrodes to record a first signal in response to the first stimulation, wherein the first signal comprises the neural response and the first stimulation artifact; using the first one or more electrodes to issue a second stimulation waveform to the patient's spinal cord tissue, wherein the second stimulation waveform has an amplitude configured to cause a second stimulation artifact and not to evoke a neural response in the patient's spinal cord; using the second one or more electrodes to record a second signal in response to the second stimulation, wherein the second signal comprises the second stimulation artifact; aligning the first and second signals such that the second stimulation artifact is aligned with the first stimulation artifact; scaling the second signal with respect to the first signal; and subtracting the second signal from the first signal to yield a third signal that comprises the first neural response and stimulation artifact that is smaller than the first stimulation artifact. ### Claim 10 (depends on 9) The method of claim 9, wherein aligning the first and second signals comprises cross-correlating the first and second signals. ### Claim 11 (depends on 9) The method of claim 9, wherein further comprising determining a beginning and end of the stimulation artifact. ### Claim 12 (depends on 11) The method of claim 11, wherein in determining a beginning and end of the stimulation artifact comprises using inverse stimulation polarity. ### Claim 13 (depends on 9) The method of claim 9, further comprising determining one or more features of the first evoked neural response. ### Claim 14 (depends on 13) The method of claim 13, further comprising altering the first stimulation waveform based on the determined one or more features of the first evoked neural response. ### Claim 15 A system for providing electrical stimulation to a patient's spinal cord using one or more electrode leads implantable in the patient's spinal column, wherein each electrode lead comprises a plurality of electrodes, the IPG comprising: an implantable pulse generator (IPG) and an external device, wherein the IPG is configured to: cause a first one or more of the electrodes to issue a supra-threshold stimulation waveform to the patient's spinal cord tissue, wherein the supra-threshold stimulation waveform is configured to evoke a neural response in the patient's spinal cord; cause a second one or more of the electrodes to record a first signal in response to the supra-threshold stimulation, wherein the first signal comprises the neural response and a first stimulation artifact; cause the first one or more electrodes to issue a sub-threshold stimulation waveform to the patient's spinal cord tissue, wherein the second stimulation waveform is configured to not to evoke a neural response in the patient's spinal cord; and cause the second one or more electrodes to record a second signal in response to the second stimulation, wherein the second signal comprises the second stimulation artifact; wherein the external device is configured to: receive the first and second signals from the IPG; align the first and second signals such that the second stimulation artifact is aligned with the first stimulation artifact; scale the second signal with respect to the first signal; and subtract the second signal from the first signal to yield a third signal that comprises the neural response. ### Claim 16 (depends on 15) The system of claim 15, wherein the third signal further comprises a stimulation artifact that is smaller than the stimulation artifact of the first signal. ### Claim 17 (depends on 15) The system of claim 15, wherein aligning the first and second signals comprises cross-correlating the first and second signals. ### Claim 18 (depends on 15) The system of claim 15, wherein the control circuitry is further configured to determine a beginning and end of the stimulation artifact. ### Claim 19 (depends on 18) The system of claim 18, wherein in determining a beginning and end of the stimulation artifact comprises using inverse stimulation polarity. ### Claim 20 (depends on 15) The IPG of claim 15, wherein the neural response is an evoked compound action potential (ECAP).