US-20260123871-A1 - Systems and Methods of Electrode Switching for Neurophysiological Sensing and Stimulation

US20260123871A1US 20260123871 A1US20260123871 A1US 20260123871A1US-20260123871-A1

Abstract

An integrated switch matrix for a medical device system used for long-term monitoring of electroencephalogram (EEG) signals and mapping of the brain through cortical stimulation is configured to switch functions of various electrodes associated with the system in response to user needs. The programmable switch matrix is integrated in an EEG recording device and allows for connecting any patient electrode(s) to a ground circuit, connecting any patient electrode to a common reference, connecting a selected common reference to any or all recording device(s) in the system and, connecting any patient electrode(s) to anode and/or cathode outputs of a neurostimulator for multi-contact cortical stimulation.

Inventors

Rose Rehfeldt
Ethan Rhodes
Richard A. Villarreal
Wayne Dearing
James Wadsworth

Assignees

CADWELL LABORATORIES, INC.

Dates

Publication Date: 20260507
Application Date: 20251231

Claims (13)

1 . A programmable switch matrix adapted for use with a recording device in a neuromonitoring system, comprising: an electrode connection link, wherein the electrode connection link is in data communication with a plurality of electrodes; a programmable ground switch matrix in communication with the electrode connection link; a programmable reference switch matrix in communication with the programmable ground switch matrix and comprising a first output in communication with input channels of the recording device and a second output; a ground circuit connected to the programmable ground switch matrix; and two or more switches in data communication with the second output of the programmable reference switch matrix and with the input channels of the recording device, wherein the two or more switches comprise at least a programmable stimulation anode switch matrix and a programmable stimulation cathode switch matrix and wherein, in response to commands from a microcontroller, the programmable switch matrix is configured to enable any electrode or combination of electrodes of the plurality of electrodes to function as a common reference.
2 . The programmable switch matrix of claim 1 , further comprising a buffer in line between the communication of the two or more switches with the programmable reference switch matrix.
3 . The programmable switch matrix of claim 1 , further comprising at least one set of input/output ports configured to enable connection with at least one recording device.
4 . The programmable switch matrix of claim 3 , further comprising a programmable stimulation anode switch matrix in communication with the patient connection link and the at least one set of input/output ports.
5 . The programmable switch matrix of claim 3 , further comprising a programmable stimulation cathode switch matrix in communication with the patient connection link and the at least one set of input/output ports.
6 . The programmable switch matrix of claim 1 , wherein, in response to commands from the microcontroller, the programmable switch matrix is configured to enable any electrode or combination of electrodes of the plurality of electrodes to function as a common ground electrode.
7 . The programmable switch matrix of claim 1 , wherein, in response to commands from the microcontroller, the programmable switch matrix is automatically configured, without requiring manual intervention by a user, to enable any electrode or combination of electrodes of the plurality of electrodes to function as a common ground electrode if a previously designated ground electrode is damaged or disconnected.
8 . The programmable switch matrix of claim 1 , wherein, in response to commands from the microcontroller, the programmable switch matrix is configured to enable any electrode or combination of electrodes of the plurality of electrodes to function as a global common reference for all recording devices in data communication with the programmable switch matrix.
9 . The programmable switch matrix of claim 1 , wherein the programmable switch matrix is further configured to function in at least one of a sensing mode or in a stimulation mode.
10 . The programmable switch matrix of claim 9 , wherein, when in a stimulation mode, the programmable switch matrix is configured to provide multi-contact cortical stimulation by allowing any combination of electrodes of the plurality of electrodes to be configured as anodes or cathodes.
11 . The programmable switch matrix of claim 9 , wherein, when in a stimulation mode, the programmable switch matrix is configured to provide multi-contact cortical stimulation by allowing any combination of electrodes of the plurality of electrodes to be stimulated simultaneously.
12 . The programmable switch matrix of claim 1 , further comprising a set of ports adapted to provide power from a power module in communication with the recording device.
13 . The programmable switch matrix of claim 1 , wherein a display unit of the neuromonitoring system is configured to provide a user a graphical user interface comprising a plurality of inputs adapted to receive a selection of a function for each electrode of the plurality of electrodes.

Description

CROSS-REFERENCE The present application is a division application of U.S. patent application Ser. No. 16/678,582, titled “Systems and Methods of Electrode Switching for Neurophysiological Sensing and Stimulation” and filed on Nov. 8, 2019, which relies on U.S. Patent Provisional Application No. 62/758,303, of the same title and filed on Nov. 9, 2018, for priority, both of which are herein incorporated by reference in their entirety. FIELD The present specification is related generally to the field of neurophysiological sensing and/or stimulation. More specifically, the present specification is related to an integrated switch matrix for a medical device system used for long-term monitoring of bioelectrical signals and/or mapping of the brain through cortical stimulation. BACKGROUND Electroencephalography is the neurophysiologic sensing and measurement of electrical activity of the brain by recording signals acquired from electrodes, which may be placed on the scalp, intracranially, on the surface of the brain, or within the brain tissue, and connected to an amplifier or recording device. The resulting traces are known as an electroencephalogram (EEG) and represent an electrical signal (postsynaptic potentials) from a large number of neurons. Long-term electroencephalographic monitoring (LTM), intracranial EEG (iEEG) and cortical stimulation mapping (CSM) are directed towards identifying, mapping and monitoring neural structures in the brain with the goal of locating areas of the brain where epileptic seizures are occurring and preserving the structural integrity of these neural structures during physically invasive procedures such as surgery. For example, cortical stimulation mapping (CSM) is a type of electrocorticography that involves a physically invasive procedure and aims to localize the function of specific brain regions through direct electrical stimulation of the cerebral cortex. Identifying, mapping and monitoring neural structures comprises applying electrical stimulation at or near an area of the brain where EEG abnormalities associated with seizure disorders are believed to be located. Electrical stimulation is transmitted through the brain to excite the associated sensory, motor or functional areas of the cerebral cortex that may reside in the location of interest. An electrical impulse is generated in the brain, as a result of the excitation, that can be sensed using recording electrodes or by visually observing physical responses in the patient such as limb movement or speech patterns, thereby indicating presence of a nerve center to a surgeon. Electrocorticography (ECoG) and stereoelectroencephalography (sEEG) are methods of intracranial EEG monitoring and cortical mapping that require high channel count recording and stimulating devices. These systems use amplifiers capable of receiving input electrodes typically in a range of 21 to 256 electrodes and sometimes more than 500 electrodes. In ECoG, electrodes are placed on the cerebral cortex via a craniotomy. In sEEG, depth electrodes may be placed via small holes (burr holes) drilled in the skull. ECoG and sEEG may be used when standard EEG monitoring results are inconclusive, particularly for epilepsy patients. Since ECoG and sEEG use strip or grid electrodes and depth electrodes on the surface of the brain and in the brain respectively, they provide a benefit of using electrodes that are closer to the area(s) producing seizures than electrodes placed on the scalp in standard EEG monitoring. In addition, electrodes placed directly on or in the brain have the advantage of recording signals without the interference of skin, fat tissue, muscle or bone. ECoG and sEEG may be used to monitor, assess and map the brains of epilepsy patients who may benefit from surgery and have not responded to less invasive treatments, including pharmaceuticals. Monitoring will indicate to physicians an area of epileptogenic brain tissue that is the site of origin of recurrent seizures and mapping will indicate to physicians functional areas of the brain to be safeguarded during surgery. Functional mapping involves using the electrodes (grid or strip) to stimulate the brain and record signals to identify the underlying function of a brain region, such as language, sensation, or motor function. ECoG and sEEG typically involve long term monitoring where electrodes are placed intracranially during a surgery, then the monitoring device remains connected to the patient for monitoring and recording to identify areas of pathological brain activity. Once the area of epileptic activity is located, the device may be used during surgery or in a patient monitoring room to monitor or stimulate nerves to map important functional areas of the brain that should be avoided during surgery. When a discrete epileptogenic region of the brain is identified and can be removed without the introduction of unacceptable additional neurological deficits, the respective surgery is performed. C