Devices and methods for sensing physiological signals during stimulation therapy

Patent metadata

Field	Value
Publication number	US-11103172-B2
Application number	US-201314064801-A
Country	US
Kind code	B2
Filing date	Oct 28, 2013
Priority date	Oct 28, 2013
Publication date	Aug 31, 2021
Grant date	Aug 31, 2021

Abstract

Devices and methods provide for the sensing of physiological signals during stimulation therapy by preventing stimulation waveform artifacts from being passed through to the amplification of the sensed physiological signal. Thus, the amplifiers are not adversely affected by the stimulation waveform and can provide for successful sensing of physiological signals between stimulation waveform pulses. A blanking switch may be used to blank the stimulation waveform artifacts where the blanking switch is operated in a manner synchronized with the stimulation waveform so that conduction in the sensing path is blocked during the stimulation pulse as well as during other troublesome artifacts such as a peak of a recharge pulse. A limiter may be used to limit the amplitude of the sensed signal, and hence the stimulation artifacts, that are passed to the amplifier without any synchronization of the limiter to the stimulation waveform.

First claim

What is claimed is:

1. A method of sensing physiological signals while stimulation therapy is being provided by using a device that comprises:
a sensing electrode;
a blanking switch;
a first electrically conductive pathway connected between the sensing electrode and the blanking switch;
a sensing amplifier;
a second electrically conductive pathway connected between the sensing amplifier and the blanking switch;
a controller, the method comprising:
while a stimulation signal having a stimulation phase and a recharge phase is being output from a first electrode at a stimulation site, sensing a physiological signal at a second electrode in proximity to the stimulation site to produce a sensed signal; and
during at least a portion of the recharge phase and a next stimulation phase of the stimulation signal that follows the recharge phase, the controller maintains the blanking switch in a non-conducting state to blank the sensed signal and during at least the portion of the recharge phase and the next stimulation phase, the controller maintains the blanking switch in a conducting state thereby not blanking the sensed signal for a period of time after the next subsequent stimulation phase that follows the recharge phase and prior to a next recharge phase that follows the next stimulation phase, the next recharge phase occurring prior to any stimulation phase that occurs after the next stimulation phase, the period of time that the controller maintains the blanking switch in the conducting state being longer than an amount of time between an end of the recharge phase and a beginning of the next stimulation phase that follows the recharge phase.

2. The method of claim 1 , wherein the device includes a filter electrically connected between the sensing electrode and the sensing amplifier.

3. The method of claim 2 , wherein the controller further blanks the sensed signal by opening a second switch in series between the blanking switch and the filter and closing a third switch in parallel with the blanking switch and the second switch.

4. The method of claim 2 , wherein the filter comprises a low pass filter and a high pass filter.

5. A device for sensing a physiological signal while stimulation therapy is being provided, comprising:
a sensing electrode;
a blanking switch;
a first electrically conductive pathway connected between the sensing electrode and the blanking switch;
a sensing amplifier;
a second electrically conductive pathway connected between the sensing amplifier and the blanking switch; and
a controller that maintains the blanking switch in a non-conducting state during at least a portion of the recharge phase and a next stimulation phase of a stimulation signal that follows the recharge phase and that maintains the blanking switch in a conducting state for a period of time after the next stimulation phase that follows the recharge phase and prior to a next recharge phase that follows the next stimulation phase, the next recharge phase occurring prior to any stimulation phase that occurs after the next stimulation phase, the period of time that the controller maintains the blanking switch in the conducting state being longer than an amount of time between an end of the recharge phase and a beginning of the next stimulation phase that follows the recharge phase.

6. The device of claim 5 , further comprising a filter, wherein the filter comprises a low pass filter and a high pass filter positioned electrically between the blanking switch and the sensing amplifier.

7. The device of claim 5 , further comprising a stimulation engine, and wherein the controller triggers the stimulation engine to produce a stimulation pulse of the next stimulation phase.

8. The device of claim 7 , wherein the controller triggers the stimulation engine to produce the recharge phase of the stimulation signal in response to detecting a time for the presence of the recharge phase.

9. The device of claim 5 , wherein the blanking switch comprises a plurality of individual switches.

10. A device for sensing a physiological signal while stimulation therapy is being provided, comprising:
a sensing electrode;
a blanking switch;
a first electrically conductive pathway connected between the sensing electrode and the blanking switch;
a sensing amplifier;
a second electrically conductive pathway connected between the sensing amplifier and the blanking switch; and
a controller that maintains the blanking switch in a non-conducting state during at least a portion of a recharge phase and a next stimulation phase of a stimulation signal that follows the recharge phase and that maintains the blanking switch in a conducting state for a period of time after the next stimulation phase that follows the recharge phase and prior to a next recharge phase that follows the next stimulation phase, the next recharge phase occurring prior to any stimulation phase that occurs after the next stimulation phase, the period of time that the controller maintains the blanking switch in the conducting state being longer than an amount of time between an end of the recharge phase and a beginning of the next stimulation phase that follows the recharge phase, wherein the recharge phase comprises an active recharge pulse.

11. The device of claim 10 , wherein the controller starts an instance of blanking of at least a portion of the active recharge pulse and continues the instance of blanking until a stimulation pulse occurring after the active recharge pulse ends.

12. The device of claim 11 , wherein the active recharge pulse begins after an evoked compound potential (EVCP) portion of the sensed signal, and wherein sensing comprises sensing the EVCP portion.

Assignees

• Medtronic Inc

Inventors

• Stanslaski Scott R
• Cong Peng
• Santa Wesley A
• Denison Timothy J

Classifications

• A61B5/24 Primary

  Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof · CPC title

• A61B5/7217 Primary

  of noise originating from a therapeutic or surgical apparatus, e.g. from a pacemaker · CPC title

• A61B5/7225

  Details of analogue processing, e.g. isolation amplifier, gain or sensitivity adjustment, filtering, baseline or drift compensation (input circuits for detecting, measuring, or recording bioelectric or biomagnetic signals A61B5/30; specific diagnostic methods using bioelectric or biomagnetic signals A61B5/316) · CPC title

• A61B5/4836

  Diagnosis combined with treatment in closed-loop systems or methods (A61B5/0036 takes precedence) · CPC title

• A61N1/36125

  Details of circuitry or electric components · CPC title