MOBILE ELECTROENCEPHALOGRAM SYSTEM AND METHODS

Provided are systems and method for obtaining electric signal biosignal readings using a portable device.

BACKGROUND

The electrical signals from a living organism can provide critical diagnostic information. Historically, scientists and physicians have arranged small flat metal discs, called electrodes, on the skin to record bioelectric or electric signals. The electrodes can be configured to record electrocardiogram (ECG) from the heart, electromyogram (EMG) from a muscle group or electroencephalogram (EEG) from the brain. The electrophysiological monitoring method to track and record electrical wave patterns of an organ can provide critical information about its health and functioning.

In particular, most existing technologies use wearable designs that arrange the electrodes using tape, band, straps, caps or headsets to mechanically attach the electrodes on the body part. For either type of application, a substantial amount of time is needed for placement of the electrodes on a patient’s scalp by a specialized technician, which prevents the use of EEG to identify brain health in the field such as immediately after an accident for urgent short-term screening or outside of the confines of a hospital or medical center. Rigid geometry designs such as caps or headset system for EEG may not accommodate all head shapes and sizes. Such designs may also inconvenience the medical practitioners as they have to carry multiple devices with different sizes and completely remove the system when there is poor signal quality to exfoliate scalp sites and improve the signal-to-noise ratio.

Current EEG technology is expensive and is complex to setup, requiring a specialized technician for each application of EEG. Several reports in medical literature posit the time criticality of brain dysfunctions. When doctors have to wait up to 48 hours for objective brain data provided by EEGs, they end up treating patients blindly which can cause worse damage to the patient than not treating altogether. In less populated areas, the time from injury to monitoring increases greatly effecting the outcomes of those patients.

Different groups have attempted to create confined wearable systems with a reduced number of electrodes that may reduce the complexity of setup but they present their own limitations. For example, an EEG headband that sits on the crown may lack critical coverage of patient’s central scalp region, reducing their versatility to screen different brain conditions. Some wearable designs have utilized an array of electrodes in a fixed pattern worn by the operator on one finger or multiple fingers like a glove. Multiple electrodes on a fabric glove present challenges in manufacturing, fragility and convenience. The loose wires may introduce additional motion artifact to sensitive electric signals. Such operator wearable designs may also increase the chances of cross-infection if there is a tear in the holding fabric. Some handheld EEG devices require professionals in electrode placement for application and have not accounted for subtle motion artifacts from holding the device to the scalp’.

EEG devices that are easy to use and rapidly deploy to multiple configurations with reduced number of electrodes will ensure that doctors would not have to wait for technicians and machines to become available, potentially saving lives and reducing hospital liability in the process. Such devices act as flexible montage systems where a limited number of electrodes can be moved to different configurations to get a wider coverage.

Annually in the United States, a total of 2.5 million patients present nonconvulsive seizures (NCS). Consequently, when NCS persists for more than 5 minutes, the patient enters nonconvulsive status epilepticus (NCSE). NCSE is characterized as prolonged, high-amplitude, uncontrolled electrical disturbances in the brain. It can be only diagnosed using EEGs due to lack of any overt clinical signs and its common presentation alongside altered mental state. Furthermore, NCSE also presents in 23% of all neuro-ICU patients with critical illnesses such as stroke, cardiac arrest and traumatic brain injury. Due to the critical illnesses associated with NCSE, patients suffer from up to 51% mortality, high morbidity and cognitive dysfunction. However, even the most well-established, high-capacity hospitals possess a limited number of machines, with many smaller hospitals lacking any EEG equipment at all. During the night shift, there are less technicians available on-site for setup, leaving even the physicians without immediate access to the EEG needed for NCSE diagnosis.

NCSE is misdiagnosed in up to 93% cases in the emergency departments due to subjective assessments and several cases are unaccounted for due to under-diagnosis. Current clinical guidelines and time sensitivity of these seizures compels neurologists to administer anti-epileptic drugs (AED) based on clinical impressions rather than waiting for EEG data. However, uninformed treatment without EEG can result in a similar mortality rate as NCSE left untreated. Several AEDs, such as benzodiazepines, cause significant hypotension and respiratory suppression in up to 40% of patients. Patients suffering from respiratory suppression require intubation and are admitted to the intensive care unit (ICU). Evidence from studies show that 10-15% of patients were treated with AED’s suspected based on clinical impressions only but were later found to have normal EEG activity. Thus, an easy to setup flexible montage EEG will increase the frequency of EEG evaluation during rounds and at initial suspicion, increasing the administration of accurate treatments.

Portable and flexible montage EEGs may also create a gateway for objective concussion or mild traumatic brain injury screening. There are over 5.5 million suspected concussion cases each year with athletes in high impact sports disproportionately affected. Current concussion screening protocols are unreliable and miss half of all cases for mild injuries. Subjective questionnaires like the Sport Concussion Assessment Tool-3 are vulnerable to tester bias and lack a long-term perspective of patient recovery. Imaging techniques like computed tomography are done at the hospital and miss 91% of concussion cases. Easy-to-use and self-administrable flexible montage EEGs can dramatically simplify the data collection process when compared to existing technologies. Now, athletes can record a healthy baseline EEG when they are injury-free. Coaches and trainers can administer such devices on the sidelines to record EEGs right after an injury and the athlete can self-administer it from their home to monitor recovery. With this simplified process, we can track athlete health all the way from high school through the end of their professional career. This is critical as detrimental effects of concussions are often caused by cumulative mild trauma.

SUMMARY

Provided herein are embodiments of portable system for receiving electric signals from a surface, comprising: a portable device for detecting electrical activity comprising: a housing; one or more legs extending from the housing; one or more electrodes provided on a distal end of each of the one or more legs; one or more sensors configured to determine a position of the one or more electrodes, wherein the one or more electrodes are placed on the surface to detect the electric signals.

In some embodiments, the system further comprises a first computing device provided within the housing, the first computing device comprising a processor operatively coupled to the one or more sensor and a non-transitory computer readable storage medium with a computer program including instructions executable by the processor causing the processor to: i) calibrate a position of the one or more electrodes and set an origin, ii) receive data from the one or more sensors to track the position of the one or more electrodes, and iii) record the electric signals detected by the one or more electrodes.

In some embodiments, the processor of the first computing device is further configured to transmit the electrical signal to a second computing device, the second computing device configured to receive the electric signals transmitted from the first computing device of the portable device and positional data corresponding to the position of the one or more electrodes, and wherein the second computing device comprises a second processor and a non-transitory computer readable storage medium with a second computer program including instructions executable by the processor causing the second processor to generate a graphical representation of the electrical signals detected by the one or more electrodes. In some embodiments, the second computer program further comprises instructions to generate a graphical representation of the positional data of the one or more electrodes. In some embodiments, the first computing device communicates to the second computing device via wireless networking. In some embodiments, the wireless networking comprises Bluetooth transmission.

In some embodiments, the one or more sensors comprise an image sensor. In some embodiments, the image sensor is a camera. In some embodiments, the camera is a 120° field of view camera. In some embodiments, the camera is positioned such that the electrodes are within a field of view of the camera.

In some embodiments, the portable device further comprises one or more inertial sensors, and wherein the computer program includes further instructions causing the processor to receive data from the one or more inertial sensors to track the position of the one or more electrodes. In some embodiments, the one or more inertial sensors are configured to provide a six-axis information by combining accelerometer and gyroscope. In some embodiments, the housing further comprises a port to reversibly receive a wired electrode.

The system of any one of claims 1, wherein the portable device further comprises one or more feet, each foot provided at a distal end of the one or more legs, wherein the one or more electrodes are disposed on the one or more feet. In some embodiments, each foot comprises a compressible pad. In some embodiments, each foot is connected to each leg via a pin joint. In some embodiments, the portable device further comprises one or more tension wires, each tension wire running from a foot of the one or more feet, through a leg connected to said foot, and to the housing.

In some embodiments, the portable device further comprises one or more force sensors, wherein the force sensors measure a force applied to the surface by the one or more electrodes. In some embodiments, one force sensor is provided for each of the one or more legs. In some embodiments, the portable device further comprises one or more force sensors, wherein the force sensors measure a force applied to the surface of the subject by the one or more electrodes. In some embodiments, the one or more electrodes comprise gold-cup electrodes. In some embodiments, the portable device further comprises a battery.

In some embodiments, the portable device comprises a closed configuration and an open configuration, wherein the one or more electrodes are closer to one another in the closed configuration than in the open configuration. In some embodiments, the portable device further comprises one or more tension wires, each tension wire running from the distal end of each leg, through each leg, and to the housing. In some embodiments, the tension wire biases the one or more legs to the closed configuration. In some embodiments, the housing comprises openings sized to fit the one or more legs to limit a distance between the one or more electrodes in the open configuration.

In some embodiments, the portable device comprises three legs. In some embodiments, the portable device further comprises one or more feet, each foot provided at a distal end of the one or more legs, wherein the one or more electrodes are disposed on the one or more feet. In some embodiments, each foot comprises a compressible pad. In some embodiments, each foot is connected to each leg via a pin joint. In some embodiments, the portable device further comprises one or more tension wires, each tension wire running from a foot of the one or more feet, through a leg connected to said foot, and to the housing. In some embodiments, the portable device comprises a closed configuration and an open configuration, wherein the one or more electrodes are closer to one another in the closed configuration than in the open configuration, and wherein the tension wire biases the one or more legs to the closed configuration.

In some embodiments, the portable device comprises an actuator to rotate the one or more legs. In some embodiments, rotation of the one or more legs comprises a rotation toward or away from a center axis of the portable device such that the electrodes move toward or away from one another. In some embodiments, the actuator rotates the one or more legs simultaneously.

In some embodiments, the one or more tension wires are configured to keep the one or more electrodes in contact with the surface while taking receiving the electric signals. In some embodiments, the surface is a skin surface of a subject. In some embodiments, the skin surface is a scalp of a subject, and the system is configured to generate an electroencephalogram.

Provided herein are embodiments of a method for detecting electric signals from a with a portable device, the portable device comprising: a housing; one or more legs extending from the housing; one or more electrodes provided on a distal end of each of the one or more legs; and one or more sensors configured to determine a position of the one or more electrodes, the method comprising: placing the one or more electrodes on a surface of a subject to detect one or more electric signals from a first region of the surface of the subject; moving the one or more electrodes to a subsequent region of the surface of the subject; detecting one or more electric signals from the subsequent region of the surface of the subject; repeating steps (b) and (c) until one or more electric signals have been obtained from all desired regions of the surface of the subject.

In some embodiments, the step of moving the one or more electrodes to the subsequent region of the surface of the subject further comprises keeping the one or more electrodes in contact with the surface of the subject. In some embodiments, the method further comprises a step of holding the one or more electrodes at the first region and a step of holding the one or more electrodes at the subsequent region. In some embodiments, the method further comprises a step of receiving feedback from the portable device prior to moving the one or more electrodes to the subsequent region. In some embodiments, the feedback is indicative of the transmitting of the electrical signals obtained by the one or more electrodes. In some embodiments, the feedback is indicative of the capturing and storing of data corresponding to the electrical signals obtained by the one or more electrodes. In some embodiments, the data comprises a position of each of the one or more electrodes. In some embodiments, the data comprises voltage fluctuations detected by the one or more electrodes. In some embodiments, the feedback comprises haptic feedback, visual feedback, or a combination thereof.

In some embodiments, the surface of the subject is a scalp. In some embodiments, the method generates an electroencephalogram, and wherein the portable device in configured as a portable electroencephalogram device. In some embodiments, the method is performed by the subject. In some embodiments, the method further comprises a step of engaging a button on the portable device to calibrate the position of the one or more electrodes at the origin.

In some embodiments, the portable device further comprises a computing device provided within the housing, the computing device comprising a processor operatively coupled to the image sensor and a non-transitory computer readable storage medium with a computer program including instructions executable by the processor causing the processor to: i) calibrate a position of the one or more electrodes and set an origin, ii) receive data from the one or more sensors to track the position of the one or more electrodes, and iii) record electric signals obtained from the one or more electrodes. In some embodiments, the processor of the computing device is further configured to transmit the electrical signals to an external computing device.

In some embodiments, provided herein is a portable system for receiving electric signals from a surface, comprising: a portable device for detecting electrical activity comprising: a housing; one or more legs extending from the housing; one or more electrodes provided on a distal end of each of the one or more legs; and one or more sensors configured to determine a position of the one or more electrodes, wherein the one or more electrodes are placed on the surface to detect the electric signals.

In some embodiments, provided herein is a portable system for receiving electric signals from a surface, comprising: a portable device for detecting electrical activity comprising: a housing; one or more legs extending from the housing; one or more electrodes provided on a distal end of each of the one or more legs; and one or more sensors configured to determine a position of the one or more electrodes, wherein the one or more electrodes are placed on the surface to detect the electric signals; and a first computing device provided within the housing, the first computing device comprising a processor operatively coupled to the one or more sensor and a non-transitory computer readable storage medium with a computer program including instructions executable by the processor causing the processor to: calibrate a position of the one or more electrodes and set an origin, receive data from the one or more sensors to track the position of the one or more electrodes, and record the electric signals detected by the one or more electrodes.

INCORPORATION BY REFERENCE

DETAILED DESCRIPTION

Embodiments disclosed relate to an architecture for a portable device for measuring electrical signals from a surface. In some embodiments, the surface is a skin surface of a subject. In some embodiments, the surface of the subject is a scalp and the portable device is configured as an electroencephalogram (EEG) device. In some embodiments, the portable EEG device is configured with greater electrode adjustability that enables greater ease of use than possible with traditional taped or head-wearable based EEG currently available on the market. This will allow for easier access to targeted areas of the brain leading to an overall decrease in time to monitor patient brain data. The configuration may further allow for self-administration of testing and/or monitoring, such as electroencephalography or electrophysiological monitoring. The configuration may allow for someone who is inexperienced in electroencephalography to obtain accurate electroencephalogram readings to provide sufficient data for monitoring of brain activity and/or diagnosis of health conditions.

In some embodiments, provided herein is a PenEEG (pEEG) device. In some embodiments, PenEEG is a handheld, configurable electrode, two-channel system that provides expedited NCSE identification with minimal training to operate. As such the pEEG may be rapidly deployed for NCSE screening in one-minute. In some embodiments, when a clinician suspects NCSE, they will 1) retrieve the device, 2) activate a tablet application which pairs with the pEEG, and 3) apply the pEEG to the first screening location on a patient’s scalp. Nurses and technicians may also operate the device if the clinician is off-site. The tablet may indicate the first screening configuration to the operator, prompting them to then exfoliate those locations. The three pivoting legs of the pEEG may be opened. The legs of the device may comprise cup electrodes at the distal end. The electrodes may be prepared by the application of the conductive gel. In some embodiments, the pEEG is placed on the scalp and an image-based tracking system verifies that the actual position matches the position indicated for each electrode in a configuration. In some embodiments, an integrated smart feedback system in the pEEG tracks the electrode contact and alerts the operator when the contact is insufficient and requires adjustments. EEG signals may be displayed on the tablet in real-time as the operator records thirty-second epochs at each indicated configuration to acquire sufficient data for seizure activity quantification. This may allow clinicians to make informed, expedited treatment decisions during on-site or off-site review.

Ease of use may position the pEEG system for rapid adoption by neurologists, nurses, and EEG technicians alike for on-the-go monitoring. The configurable electrode system may be analogous to a stethoscope with 2 channels, designed to be rapidly repositioned at multiple electrode configurations on the scalp.

A guided electrode positioning system (GePS) is designed to minimize the actions taken by an operator during use. The GePS tracks the device position to A) verify if the operator has precisely aligned the electrodes at the correct configuration and B) automatically catalog the EEG signal with the verified configuration. Automated tracking and cataloging through GePS reduces the operational workload of data management and expedites data access for future review.

According to some embodiments of the disclosure, the EEG device features a housing to provide a central body by which links and electrodes can be adjusted, wherein a plurality of electrode positions and angles can be achieved. The position of the electrode is adjustable, as one or more segments forming the leg can be angled in relation to the housing to change the angle of attack by the electrode when placing on the scalp. As a result, a single portable EEG device may be compatible for any montage accessible via traditional EEG. The adjustability and ability to rapidly position this EEG at multiple montages over a couple minutes will combat the disadvantages associated with the setup and administration of the traditional and head-mounted EEG systems, allowing for easier access to brain data and decreased procedural times resulting in better treatment for patients.

Some embodiments of this improved EEG and housing includes two main components: a housing and one or more legs (hereinafter, “leg”). The leg of may be fixed in the open position using physical barriers such as interior surfaces sized to fit exterior surfaces of the leg. In this way, the leg cannot be rotated about the pin axis of the housing and provide a sturdy design for single positional reading. The legs may be rigid or semirigid such that a force supplied by the user can be translated through the legs to facilitate proper contact of the electrodes to the skin surface.

An electrode with adjustable positioning can decrease the time it takes to set up and record brain signals, allowing for rapid switching between montages to provide a glance at brain function at critical areas across the brain. Neurologists, nurses, paramedics, EEG technicians can quickly read areas that would usually require a lengthy setup and preparation process. This device can also be self-administered for personal screening at home or on the go. Furthermore, an adjustable electrode allows for adaptive positioning based on each patient’s head size, providing the same one-size-fits-all functionality as present in taped electrodes to portable, wireless EEG.

Lastly, another advantage of the resulting electrode adjustability is overall improved triage of patients. When using the quick and portable EEG to perform a quick reading, the full EEG can be directed to patients who need it most; if the quick EEG spots problematic brain patterns, then a full EEG can be called. If nothing apparently dysfunctional is spotted upon initial reading with the adjustable electrode EEG, then the patient may be at a lower priority for the full EEG reading. While the system described herein does offer discrete EEG monitoring, wired electrodes can be connected to the same to provide continuous monitoring at one montage.

Referring toFIG.1A, an EEG device100operating as a flexible montage brain monitoring system is shown, according to some embodiments. In some embodiments, the EEG device100features a plurality of components, including a housing110, legs120, and body130. A portion of the housing110may be inserted through an opening of the body130, while portions of each of the legs120are inserted into openings in the housing110. Apertures in the housing110and legs120may each be sized to fit a pin to secure that leg120in a housing110opening. Alternatively, one or more of these legs120may be secured using adhesive or a fusing process. An opening in the body130may be threaded or secured to the housing110using adhesive or a fusing process.

As illustrated inFIG.1B, a cross-sectional view of the EEG device100ofFIG.1Aalong line 1B-1B is shown. In some embodiments, the housing110may be entered into the body130opening. The body130may be sized to fit electrical components necessary to record signals and provide portability which sit above the housing110. The housing110openings may be sized to fit the leg130extrusions incorporate a feature design to prevent rotation of the leg130. This feature paired with a similar feature on the legs130keep the legs130in an open position may allow for quick relocation of electrodes to accommodate multiple montages with minimal adjustment.

Referring now toFIGS.2A and2B, the housing110is shown, according to some embodiments. In some embodiments, the housing110includes an extrusion210, a constraining surface220, an opening230, a second constraining surface240, a cut250, and one or more securing points260. The extrusion210may be sized to fit the opening on the body130while the constraining surface220serves to limit the entry of housing110into the body130. The opening230may be sized to fit an extrusion on the leg120while the second constraining surface240fits with an angled surface (310as depicted inFIGS.3A-3B) on the leg120to prevent movement or rotation when the leg120is fixed to the securing point260, keeping the leg120in an open position.

As shown inFIG.2B, the opening230, the second constraining surface240, the cut250, and at securing point260are made apparent. A cut250through the housing110may provide a route for electrode wire starting from the distal end of the leg120to reach the electrical components contained in the body130. As shown inFIG.2B, the opening230, the second constraining surface240, the cut250, and at securing point260are made apparent. The angled feature of the constraining surface240may prevent rotation about the securing point260.

Referring now toFIGS.3A and3B, the leg120is shown, according to some embodiments. In some embodiments, the leg120may include an angled extrusion310, a channel320, a bend330, and an opening340. An angled extrusion310may be sized to fit the opening230and constraining surface240of the housing110. When the leg120is attached to the housing110via the securing point260, these features may prevent movement of the leg120, allowing for rapid switching of positions to different montages across the scalp with minimal adjustment needed. Since the legs120of this embodiment are secured in an open position, a bend330may be required to maintain contact between electrode and patient scalp. As shown inFIG.3B, an opening340may be sized to fit electrodes traditionally used with EEG machines. The electrode wire325may then travel up the channel320and through the cut250of the housing110to provide a signal to the electrical components in the body130. In some embodiments, the wall of the channel320is shielded to protect the electrode wire from radiative noise. In some embodiments, the channel320provides a path for both the electrode wire and a tendon.

As depicted inFIG.1B, a constraining surface (e.g.240) may limit rotation of the legs120with respect to the center axis190of the housing130. In some embodiments, a constraining surface limits the angle195formed between the leg120and the center axis190to about 45° in an open configuration. In some embodiments, the angle between the leg and the center axis in the open configuration is limited to about 35° to about 65°. In some embodiments, the angle between the leg and the center axis in the open configuration is limited to about 35° to about 40°, about 35° to about 45°, about 35° to about 50°, about 35° to about 55°, about 35° to about 60°, about 35° to about 65°, about 40° to about 45°, about 40° to about 50°, about 40° to about 55°, about 40° to about 60°, about 40° to about 65°, about 45° to about 50°, about 45° to about 55°, about 45° to about 60°, about 45° to about 65°, about 50° to about 55°, about 50° to about 60°, about 50° to about 65°, about 55° to about 60°, about 55° to about 65°, or about 60° to about 65°. In some embodiments, the angle between the leg and the center axis in the open configuration is limited to about 35°, about 40°, about 45°, about 50°, about 55°, about 60°, or about 65°. In some embodiments, the angle between the leg and the center axis in the open configuration is limited to at least about 35°, about 40°, about 45°, about 50°, about 55°, or about 60°. In some embodiments, the angle between the leg and the center axis in the open configuration is limited to at most about 40°, about 45°, about 50°, about 55°, about 60°, or about 65°. Multiple embodiments of constraining surfaces (e.g.240,740,1140, etc.) which contact angled surfaces (e.g.310,850,1250, etc.) to restrict movement of the leg and limit the angle between the leg and the center axis of the housing are depicted in the accompanying figures and described herein.

Referring now toFIG.4A, the body130is shown, according to some embodiments. In some embodiments, the body130includes an opening410, a positioning structure420, a port430and an edge440. The opening410is sized to fit the extrusion210of the housing110, while the edge440contacts the constraining surface220of the housing110to prevent the body130from fully encompassing the housing110. As shown inFIG.4B, a positioning structure420is sized to fit a positioning structure (530as depicted inFIG.5B) on the package140which orients the package140and electrical components within so that the electronics may be charged via wire through the port430. This port430may not be needed if a wireless charging application is included in the electrical components. In some embodiments, a wireless charger is provided within the electronics package140.

Referring now toFIGS.5A,5B, and5C, the package140is shown, according to some embodiments. In some embodiments, the package140includes a first slot510, a second slot520, a positioning structure530, and an opening540. A first slot510is sized to fit the electronics circuit (not shown) while the second slot520is sized to fit a battery that will power the electronics circuit. As shown inFIG.5B, an opening540is made allowing wires to pass between a first slot510and a second slot520. As shown inFIG.5C, a positioning structure530is sized to fit a positioning structure420on the body130to constrain package140in line with port430, allowing for proper connection between electrode wires passing through cut250of the housing110and the electronic circuit located in first slot510.

Referring toFIG.6A, an EEG device600operating as a flexible montage brain monitoring system is shown, according to some embodiments. The EEG device600features a plurality of parts, including a housing610, legs620, feet630and a body130. A portion of the housing610is inserted through an opening of the body130, while portions of the legs620are inserted into openings in the housing610. Apertures in the housing610and legs620are sized to fit a pin to secure a leg620in a housing610opening. Alternatively, a leg620may be secured with an extrusion on the housing610(not shown yet) and an additional part to prevent it from sliding off the extrusion on the housing610(also not shown yet). An opening in the body130may be threaded or secured to the housing610using adhesive or a fusing process.

As illustrated inFIG.6B, a cross-sectional view of the EEG device600ofFIG.6Aalong line 6B-6B is shown. Herein, the housing610is entered into the body130(seeFIG.4) opening. The body130is also sized to fit electrical components necessary to record signals and provide portability which sit above the housing610. The housing610openings sized to fit the leg620extrusions incorporate a feature design to prevent rotation of the leg620past a specified angle. This feature allows for rapid opening and closing of the legs, allowing for quick relocation of electrodes to accommodate multiple montages with minimal adjustment.

Referring now toFIG.7A, the housing610is shown, according to some embodiments. In some embodiments, the housing610includes an extrusion710, a constraining surface720, an opening730, a second constraining surface740, a supporting structure750, and securing points760. The housing610may also include a cut (e.g.250as depictedFIG.2B). The extrusion710is sized to fit the opening on the body130while the constraining surface720serves to limit the entry of housing610into the body130. As shown inFIG.7B, the opening730is sized to fit the leg620while the constraining surface740fits with an angled surface on the leg620to prevent movement or rotation past a specified angle when the leg620is fixed to the securing point760, allowing for rapid switching of the leg620between an open or closed position. A supporting structure750provides an opening through which a tendon may pass through to control the position of the feet630in relation to the housing610. As shown inFIG.7C, the supporting structure750is shaped to allow a single tendon to pass through and connect to two points on the feet630. Alternatively, the continuous supporting structure750could be represented by two discrete securing points, allowing for either a single tendon to pass through a foot630, or two tendons run in parallel to one another secured at two discrete points on a foot630.

Referring now toFIG.8A, leg620is shown, according to some embodiments. The leg620may include a rounded surface810, a first channel820, a second channel830, a constraining surface840and an angled surface850. A rounded surface810may be sized to fit the opening730of the housing610, allowing the leg620to rotate about the rounded surface810central axis. The leg620is limited by the angled surface850and the second constraining surface740of the housing610. When a leg620is attached to the housing610via a pin through or extrusion from the rounded surface810central axis, the angled surface850of the leg620and the second constraining surface740of the housing610prevent movement of the leg620past a specified angle, allowing for rapid switching of positions to different montages across the scalp with minimal adjustment needed. A constraining surface840provides a mechanical stop for the feet630, limiting the feet630to a minimum and maximum angle so that any force necessary to achieve contact will not jeopardize electrode contact with the scalp. As shown inFIG.8B, a second channel830provides a path for an electrode wire to reach the electronic components within the body. A first channel820provides a path for the tendon(s) that control the feet position, providing consistent electrode positioning with respect to the housing610and patient scalp, allowing for proper contact whether closed or open.

Referring now toFIG.9A, a foot630is shown, according to some embodiments. The foot630includes an opening910, a securing point920, a cut930, a constraining surface940, and a securing point950. As shown inFIG.9B, an opening910is sized to fit conventional EEG electrode and wires which are routed through a channel830of a leg620. Securing points920are sized to retain a tendon wire, which is routed through channels830of the leg620and then connected to a supporting structure750of a housing610. As shown inFIG.9C, a cut930is sized to fit the distal end of leg620. A constraining surface940prevents rotation past a specified angle and when paired with constraining surface840of leg620maintains the electrode contact even with a failure of a tendon. A securing point950connects the foot630to the leg620and provides an axis of rotation for the foot630with respect to the leg620, allowing the tendon to control electrode positioning with respect to the housing610.

Referring toFIGS.10A and10B, an EEG device1000operating as a flexible montage brain monitoring system is shown, according to some embodiments. The EEG device1000features a plurality of parts, including a housing1010, securing assembly1300, legs1020, feet630and a body130. A portion of the housing1010is inserted through an opening of the body130, while portions of the legs1020are inserted into openings in the housing1010. Apertures in the housing1010and legs1020are sized to fit a pin to secure a leg1020in a housing1010opening. Alternatively, at least one of the legs1020may be secured with an extrusion on the housing1010(not shown yet) and an additional part to prevent it from sliding off the extrusion on the housing1010(also not shown yet). An opening in the body130may be threaded or secured to the housing1010using adhesive or a fusing process.

As illustrated inFIG.10B, a cross-sectional view of the EEG device1000ofFIG.10Aalong line 10B-10B is shown. Herein, the housing1010is entered into the body130(seeFIG.4) opening. The body130is also sized to fit electrical components necessary to record signals and provide portability which sit above the housing1010. The housing1010openings sized to fit the leg1020extrusions incorporate a feature design to prevent rotation of the leg1020past a specified angle. The securing assembly1300serves to secure the leg1020at a plurality of discrete angles which allows for rapid adjustment of leg1020positioning, allowing for quick relocation of electrodes to accommodate multiple montages with minimal adjustment.

FIG.10Balso depicts tension-wire or tendon1055which is configured to bias a corresponding leg1020, according to some embodiments. In some embodiments, each leg1020is provided with at least one tendon1055. In some embodiments, each leg is provided with two tendons. In some embodiments, the legs are biased toward a center axis (e.g.1090) by each of the housing by the corresponding tendons.

Referring now toFIGS.11A and11B, a housing1010is shown, according to some embodiments. The housing1010may include an extrusion1110, a constraining surface1120, an opening1130, a second constraining surface1140, a supporting structure1150, securing points1160, slot1170, and cut1180. The housing1010may also include a cut (e.g. cut250as depicted inFIG.2B). The extrusion1110is sized to fit the opening on the body130while the constraining surface1120serves to limit the entry of housing1010into the body130. A slot1170is sized to fit a securing assembly1300with a cut1180to allow for a pin to disengage with cuts in a leg1020to provide a plurality of discrete angular positions. As shown inFIG.11B, the opening1130is sized to fit the leg1020while the constraining surface1140fits with an angled surface on the leg1020to prevent movement or rotation past a specified angle when the leg1020is fixed to the securing point316, allowing for rapid switching of the leg1020between plurality of discrete positions. A supporting structure1150provides an opening through which a tendon may pass through to control the position of the feet630in relation to the housing1010. As shown inFIG.11C, the supporting structure1150is shaped to allow a single tendon to pass through and connect to two points on the feet630. Alternatively, the continuous supporting structure1150could be represented by two discrete securing points, allowing for either a single tendon to pass through a foot630, or two tendons run in parallel to one another secured at two discrete points on a foot630. A cut1180provides access of so a pin may engage with the leg, stopping its rotation at a plurality of discrete positions.

Referring now toFIGS.12A and12B, a leg1020is shown, according to some embodiments. The leg1020may include a rounded surface1210, a first channel1220, a second channel1230, a constraining surface1240, an angled surface1250and cuts1260. A rounded surface1210is sized to fit the opening1130of the housing1010, allowing the leg1020to rotate about the rounded surface1210central axis. The leg1020is limited by the angled surface1250and the second constraining surface1140of the housing1010. When a leg1020is attached to the housing1010via a pin through or extrusion from the rounded surface1210central axis, the angled surface1250of the leg1020and the second constraining surface1140of the housing1010prevent movement of the leg1020past a specified angle, allowing for rapid switching of positions to different montages across the scalp with minimal adjustment needed. A constraining surface1240provides a mechanical stop for the feet630, limiting the feet630to a minimum and maximum angle so that any force necessary to achieve contact will not jeopardize electrode contact with the scalp. As shown inFIG.12B, a second channel1230provides a path for an electrode wire to reach the electronic components within the body. A first channel1220provides a path for the tendon(s) that control the feet position, providing consistent electrode positioning with respect to the housing1010and patient scalp, allowing for proper contact whether closed or open. Cuts1260provide an opening for the pin of securing assembly1300to engage with the leg1020, providing discrete angular positions for the leg1020where force may be applied without change the leg1020position.

Referring now toFIG.13A, a securing assembly1300is shown, according to some embodiments. The securing assembly1300may include a fixture1310and a pin1320. This securing assembly1300is sized to fit a slot1170of a housing1010and is configured to engage with the leg1020to prevent motion at a plurality of discrete angles. This allows for a plurality of electrode positions for each leg1020and foot630connection while maintaining electrode positioning with the tendon actuated foot630. As shown inFIG.13B, a pin1320is configured to sit within a fixture1310which may serve to locate a pin1320as it engages and disengages with a leg1020.

Referring now toFIGS.14A and14B, a fixture1310is shown, according to some embodiments. In some embodiments, the fixture1310includes an opening1410, a cut1420, and a supporting structure1430. The opening1410is sized to fit a controlling structure1510(seeFIG.15A) of the pin1320which allows for the pin1320to fit within the fixture1310and be controlled by a finger or mechanism. As shown inFIG.14B, the cut1420is sized to fit an extrusion1520(seeFIG.15A) of the pin1320, which allows the extrusion1520of pin1320to pass through the cut1420and engage with the cuts1260of leg1020. The supporting structure1430is sized to fit a locating structure1530(seeFIG.15A) on the pin1320which allows for the pin1320to move up and down without changing orientation as the extrusion1520of the pin1320engages and disengages from the cuts1260on leg1020.

Referring now toFIGS.15A and15B, a pin1320is shown, according to some embodiments. In some embodiments, the pin1320include the controlling structure1510, the extrusion1520, at the locating structure1530, and a securing point1540. The controlling structure1510serves to allow for control of the vertical location of the pin1320sitting within a fixture1310by a user finger or mechanism. The extrusion1520is sized to pass through the cut1420of the fixture1310, which is configured to engage with cuts1260of leg1010to prevent rotation of the leg1010when engaged to provide a plurality of discrete angular positions. The locating structure1530is sized to fit the supporting structure1430of the fixture1310, which is configured to maintain orientation as pin1320is moved up and down within the opening1410of the fixture1310by the controlling structure1510of the pin1320. The securing point1540is configured to engage with a spring to direct a pin1320back into a state where after raising pin1320to rotate leg1010, extrusion1520is once again engaged with cuts1260of leg1010.

As shown inFIG.16, the housing1600includes a camera1610, according to some embodiments. This camera1610is configured to be utilized by image processing algorithms in a software application to locate the housing with respect to the patient’s scalp. This provides a metric to verify that users are placing electrodes on the specified montages needed to provide assessment with minimal electrodes needed. The system may utilize accelerometers or gyroscopes with or without the camera component. There may be accelerometers or gyroscopes in the legs or electrodes to assist in tracking the device position in space as users are navigating the scalp.

As shown inFIGS.17A and17B, a gear housing is depicted, according to some embodiments. This gear housing includes a gearset (1710,1720,1730). The gearset may provide a mechanism for controlling the legs using a user’s finger or motor. The gearset may be applied to each individual leg or to a plurality of legs at the same time. Depending on which application of the gearset, each leg may be controlled independently of each other or may synchronize the movement of each leg with respect to the other legs. The gearset when paired with a motor will not require user force to move the leg position, and instead will utilize physical button presses on the device or digital button presses on the software application. In some embodiments, the gearset and legs attached, would be adjusted automatically depending on the amount of force that is applied to each leg. In some embodiments, there would be pressure/force sensors located either at the electrode, at the leg, or within the housing. When collecting the force data and impedance data (measured through the electrical components and software application), the software will be able to adjust the legs to match experimentally determined specifications to provide required contact impedance for signal integrity with minimal user input.

As shown inFIGS.18A and18B, a spring-loaded housing1800is depicted, according to some embodiments. This spring-loaded housing1800may include a first cut1810, a rail1820, a spring1830, and a second cut1840. A first cut1810may be sized to fit a leg1900to allow for a pin1910of the leg1900to move along a rail1820, directing the leg1800from a compact positionFIG.17A) to an open position (FIG.17B). The movement may be driven by a spring1830, which attaches to an extrusion1920of leg1900. The spring1830may provide downward force on an extrusion1920of the leg1900, allowing it to quickly deploy into an open position. This functionality exists to provide an instant deploying device for use in emergency situations. Hence, no user input may be required, except from clicking the deploy button to provide an EEG system when and wherever needed. In place of a spring1830, the leg1900may be driven by an actuator or pulley system.

FIG.19provides an exemplary illustration of the leg1900with pins1910and extrusion1920, according to some embodiments. The pin1910may be sized to fit rail1820, providing a path of movement for the leg1900. This may allow for a more compact version of the device where the leg1900is withdrawn into the first cut1810of housing1800and ejected into the correct position using spring tension. This design may take up less space and can be administered with minimal electronic or user intervention.

FIG.20illustrates a housing2000including a top housing2100, base2200, leg2040, cover2300, motor2050and gear2060, according to an embodiment. In some embodiment, the top housing2100is threaded and sized to fit the base2200. Within the top housing2100sits a motor2050and cover2300. In some embodiments, the motor2050shaft fits into a gear2060which will interface with the leg2040to open and close when power is applied to the motor2050.

FIGS.21A and21Billustrates a top housing2100which is comprised of an extrusion2110sized to fit within the cut2210of base2200, according to some embodiments. In some embodiments, a threaded mechanism is used to secure the top housing2100into the base2200, however other fixation techniques may be used, such as friction fit and laser adhesion. A first cut2120and a second cut2130may be sized to fit the motor2050and its rotary shaft to allow for rotation of the gear2060. First cut2120may be sized to fit cover2300which is designed to stabilize the motor2050in position for consistent application of gear2060to leg2040.

FIG.22illustrates a base2200which is comprised of a first cut2210sized to fit the extrusion2110of top housing2100, according to some embodiments. A second cut2220may be sized to fit the leg2040and a third cut2230provides an opening for the gear2060to engage with the leg2040, translating the rotary motion of the gear2060into opening or closing of the leg2040.

FIG.23illustrates a cover2300which is comprised of a first cut2310sized to fit the motor2050, according to some embodiments. An extrusion2320may be sized to fit the second cut2130of top housing2100. The cover2300may keep the motor and shaft in position during operation so the gear may consistently engage with leg to translate rotary movement to angular displacement.

FIGS.24A and24Bdepicts a pen assembly2400which is comprised of housing2500, driver2600, translator2700, constraining body2800and leg2900. In some embodiments, a hand-driven, rotational method of opening and closing the legs2900is provided. In some embodiments, a user rotates driver2600, translator2700translates rotation into axial movement and acts upon leg2900to change its angle.

FIGS.25A and25Bdepict a housing2500including first cut2510, second cut2520, third cut2530, holes2540and securing cut2550, according to some embodiments. A first cut2510may be sized to fit translator2700as it changes position based on driver 2600 rotation, changing angle of legs2900. A second cut2520may be sized to fit leg2900and provide a physical constraint to limit its motion to a desired angle. A third cut2530may provide an opening for extrusion2910of leg2900to engage with surface2730of translator2700. Holes2540may serve as a common axis about which leg2900rotates. Securing cut2550is sized to fit securing extrusion2820of constraining body2800.

FIGS.26A and26Billustrates a driver2600comprised of inner thread2610and outer surface2620, according to some embodiments. Inner thread2610may interface with outer thread2710of translator2700to change translator2700position and leg2900angle. In some embodiments, as a user contacts the outer surface2620and rotates translator2600, inner thread2610will cause translator2700to change position and press against extrusion2910of leg2900.

FIGS.27A and27Bdepict a translator2700which is comprised of outer thread2710, inner cut2720and surface2730, according to some embodiments. In some embodiments, outer thread2710is sized to interface with inner thread2610of driver2600which facilitates translator2700movement when driver2600is rotated by user. Inner cut2720may be sized to allow securing extrusion2820of constraining body2800to engage with securing cut2550of housing2500without interference. In some embodiments, a surface2730contacts extrusion2910of leg2900as translator2700axial position is changed by user rotation of driver2600, changing leg2900angle.

FIG.28depicts a constraining body2800which is comprised of foundation2810and securing extrusion2820, according to some embodiments. In some embodiments, a foundation2810provides a surface on which an electronics covering can sit and prevents constraining body2800from being encompassed by driver2600and translator2700. In some embodiments, securing extrusion2820passes through inner thread2610of driver2600and inner cut2720of translator2700to engage with securing cut2550of housing2500. In some embodiments, securing extrusion2820may snap into securing cut2550of housing2500or may be fixed with an adhesive on assembly.

FIG.29depicts a leg2900which is comprised of extrusion2910and hole2920, according to some embodiments. In some embodiments, extrusion2910passes through third cut2530of housing2500to engage with surface2730of translator2700. As driver2600is rotated and translator2700changes position, surface2730applies translated force to extrusion2910which opens and closes the leg2900. Leg2900opens and closes as the translated force on extrusion2910provides a moment about hole2920axis and causes rotation, changing angle about assembled housing2400central axis.

FIGS.30A and30Billustrate an assembled housing3000including a body3100, housing3200, slider3300, and a leg3400, wherein the interaction between a cut (3410 as depicted inFIG.34) and the slider3300allow for a switch-based or sliding opening system. InFIG.30A, the slider3300is in a position which allows the leg3400to open, where the electrode can collect signals from the patient. InFIG.30B, the slider3300is in the closed position, where the leg3400is not able to open without moving the slider3300. This system may provide a lightweight mechanism for controlling the operation of the pen. In some embodiments, the mate between the leg and the switch cause the leg to lock in an open and closed position. In some embodiments, a friction fit between the leg and the switch allows for position retention at various placements between the open and closed positions.

FIGS.31A and31Bdepict a body3100to enclose components which is comprised of an opening3110, a slider cut3120, and an internal cut3130, according to some embodiments. In some embodiments, opening3110is sized to fit extrusion3210of housing3200. In some embodiments, slider cut3120is sized to fit slider3300allowing movement of slider3300to open and close the legs3400. In some embodiments, internal cut3130is produced with features that allow the slider3300to move freely within a range of motion while keeping a slider3300between body3100and housing3200. In some embodiments, the internal cut3030has features to prevent accidental slipping of the slider3300. In some embodiments, a slider3300design which eliminates force along the axis of movement when a user pulls from the leg. Internal cut3130and its features may provide slider3300position retention when a user is not applying force to the slider3300itself.

FIGS.32A,32B, and32Cdepict a housing3200which includes a cut3210, and holes3220, according to some embodiments. In some embodiments, the cut3210is sized to fit leg3400, allowing leg 3400 rotation about a pin aligned with center axis of holes3220. As slider3300position is adjusted, leg 3400 rotation occurs, opening the pen for EEG acquisition.

FIGS.33A and33Billustrate slider3300with external extrusion3310, side extrusion3320, and internal extrusion3330, according to some embodiments. In some embodiments, external extrusion3310serves as a touch point for the user when moving the slider3300to open the leg3400. Side extrusion3320interfaces with internal cut3130of body3100to maintain the slider3300in contact with leg3400. In some embodiments, internal extrusion3330interfaces with external cut3410of leg3400to open or close the leg3400when an external force is applied to slider3300.

FIG.34illustrates leg3400including cut3410and holes3420. Cut3410is sized to fit internal extrusion3330of slider3300, according to some embodiments. As the slider3300moves, internal extrusion3330will translate applied force on slider3300into force on cut3410of leg3400to rotate leg3400about hole3420which sits on axis with hole3220of housing3200.

FIGS.35A and35Bdepict a foot3500comprising compressible pad3510to reduce motion artifacts during use, according to some embodiments. In some embodiments, the compressible pad3510is provided between a top section3530and a bottom section3520of the foot3500. In some embodiments, an electrode is received by a cut3525of bottom section3520of the foot3500. In some embodiments, a tension wire or tendon attaches through cuts3535on top section3530. In some embodiments, the foot3500connects to leg through a pin fixed in hole3505.

FIG.37depicts a device3700that can be positioned on the scalp3750of the subject for bioelectric signal acquisition or stimulation is provided, according to some embodiments. In some embodiments, the device is temporarily placed on the subject scalp3750by a downward user-applied force3760to achieve sufficient contact between the electrodes and the scalp. Similarly, the devices may be withdrawn from a configuration on the scalp3750by the removal of the applied force for repositioning on another configuration. In some embodiments, the downward user-applied force3760on the electrode for connection with the subject’s scalp3750may be further improved by the application of conductive gel.

In some embodiments, a pEEG hardware has dimensions of 31 x 140 (mm) in a closed state and 95 x 120 (mm) in an open state. In some embodiments, the device comprises pivoting legs. In some embodiments, the legs are about 57.2 mm long. In some embodiments, an electrode-applying foot is provided at a distal end of each leg. In some embodiments, the foot is connected to the pivoting leg by a pin j oint. In some embodiments, the pin joint is a 2 mm pin joint. In some embodiments, the foot holds a 10 mm diameter gold-cup electrode and is controlled by a 120 mm tension-wire. The tension-wire or tendon is routed from the electrode-applying foot through the pivoting leg and secures to the housing. The tension-wire effective length may vary as the pivoting leg is opened or closed. As the length varies, the electrode-applying foot angle may be adjusted accordingly, providing increased flexion when the leg is in an open position. The tendon or tension-wire control method paired with rubber dampeners at the feet may absorb subtle movements of the operator’s hand due to related and emergent factors that may occur while the pEEG is in use. Use of an elastic tendon or tension-wire control and rubber dampeners above the electrodes may passively reduce motion artifacts while providing conformance to the patient’s head shape and size.

In some embodiments, the body or housing comprises medical-grade polycarbonate. In some embodiments, pEEG comprises an additional port for a 40-cm wire-based conductive adhesive electrode that may be neck-mounted to provide an active ground. In some embodiments, use of an additional conductive electrode increases the effective Common Mode Rejection Ration (CMRR) by approximately 20 dB.

In some embodiments, the device further comprises one or more force sensors to sense the force applied at the electrodes. In some embodiments, the force sensors are 7 x 7 mm. In some embodiments, the force sensors are analog force sensors. In some embodiments, the device comprises three force sensors. In some embodiments, the force sensors are enclosed in the pEEG housing to sense the force applied at each electrode for use in the smart feedback system.

The guided electrode positioning system (GePS) may provide positioning data corresponding to the position of the electrodes through image-based feature tracking which integrates inertial data from an accelerometer and gyroscope enclosed in the central housing. In some embodiments, the GePS further utilizes visual input from one or more cameras (e.g.1610as depicted inFIG.16). In some embodiments, the camera comprises a 120° field of view (FOV).

In some embodiments, a camera for GePS will be recessed into the housing at an offset from the central line with respect to the reference electrode. In some embodiments, the offset is about 12 mm. In some embodiments, the offset avoids increasing the housing size while keeping the electrodes in the 120° field of view for tracking. In some embodiments, the force sensor diaphragm located in the housing will transduce responses from a dynamic lever mechanism attached to the pivoting leg joint to relay the force experienced by the electrode-applying foot as the pEEG is positioned on the scalp.

Transmission will be facilitated by a low-power, multiprotocol 2.4 GHz Bluetooth wireless microcontroller (MCU). The device may be powered by a lithium-polymer battery. The battery may be supported by a battery manager. A charging port (e.g.430depicted inFIGS.4A and4B) may be provided to recharge the battery.

In some embodiments, the device pairs with a custom cross-platform application (iOS, Android and Windows) deployed on a Bluetooth-capable or Wi-Fi capable mobile device, to display the EEG signals. Data may be stored on the hospital’s servers and accessible through a web application. Integration of mechanical design, smart electronics and GePS constitutes the pEEG ecosystem that is designed to offer seamless user-application. In some embodiments, the device is part of a smart feedback system, which measures electrode-scalp impedance and applied electrode contact force, then calculates and displays a color-coded electrode quality metric to the operator.

The utilization of the tendon or tension-wire in combination with the compressible pads on which the electrodes are disposed, according to some embodiments, is essential in maintaining sufficient contact with the skin surface to obtain accurate readings from the electrodes. In some embodiments, the tendons or tension wires bias the legs and electrodes provided thereon towards a center axis of the portable device. This system facilitates measurement of the of electrical signals with the electrodes, such that testing using the portable device may be self-administered or administered by a user who has little or no training in placement of electrodes and subsequent measurement of electrical signals. Ease of use may be especially important when obtaining sensitive measurements, such as recording electrical activity of the brain obtained by placing the electrodes on a scalp of a subject to generate an electroencephalogram. In some embodiments, systems, such as a smart feedback system described herein, further facilitate proper electrode contact is provided against the skin surface.

In some embodiments for clinical-grade signal-to-noise ratio (SNR), the electronics may be tuned to provide 1) common-mode input impedance (>100 MΩ at 60 Hz), 2) differential mode input-impedance (>10 MΩ at 60 Hz) and 3) high common mode rejection ratio (>80 dB at 60 Hz). The analog-digital circuit may be designed on a printed circuit board (PCB). The PCB may be a 15 x 40 (mm) six-layer PCB. The analog signal may be transduced by an analog front-end CMOS chip and digitized with a 24-bit analog-to-digital converter for biopotential measurements. A detachable electrode connected through the additional port may act as a bias drive increasing the effective CMRR while decreasing the ambient 60 Hz common mode noise that may appear due to electrode impedance mismatches.FIG.36depicts a housing3600comprising an additional port3650for receiving a detachable electrode, according to some embodiments. Integration of the bias drive may provide electrical isolation by dynamically driving up to 0.01 mV into the patient based on the interfering common voltage. The bias drive addition may reduce the interference observed due to the capacitive coupling of 60 Hz mains voltage and electrical equipment present inside the hospital rooms. Gold-cup electrodes may be attached to a shielded wire and positioned within the electrode legs to reduce the effects of electromagnetic interference on the EEG signal. The PCB may be encased in aluminum shielding to further minimize radiative interference. The ADC on the analog chip may be programmed for signal acquisition at 256 Hz sampling frequency. The information from the force sensors may be sampled at 2 Hz. Electrode impedance mismatches may be within 1-2 kΩ to minimize signal degradation.

The GePS may utilize image and inertial signal processing to provide the operator with simple visual cues. The cues may reflect the electrode’s actual position (AP) and the indicated position (IP) on a 10-20 EEG configuration figure on the tablet. AP may be calculated with respect to the electrode’s IP which are the specific locations suggested in the NCSE-specific GePS approach. A dedicated section on the tablet recording screen may display targeted electrode placement adjustments to the operator as a message prompt. Electrode placement success may be indicated to the operators as a green highlight when AP and IP coincide for the specific configuration. Calculations which may locate each electrode’s placement are performed by the tablet’s software interface or in the pEEG embodiment. In some embodiments, the recorded images are not visible to the operator. Images (in RGB) from the ultraminiaturized camera may be acquired at 30 frames per second (fps) with 640 x 480 pixels resolution. An initial set of images to mark an origin may be captured at least 5 mm above the center of the patient scalp. The 120° field of view along with the selected leg length (~57 mm in some embodiments) may capture electrode positions with respect to the subject’s scalp across the fronto-polar, frontal, central and parietal regions. Separate images may be recorded for temporal and occipital locations. The intensities of the 2D RGB array for each image may be readjusted to extract the contours of the scalp. The fps may be dynamically adjusted to minimize computational load by recording at a lower fps rate (e.g. 5 fps) when the force sensors report that the electrodes are placed on the scalp and a higher fps rate (e.g. 30 fps) when the electrodes lift-off. GePS performance may be finetuned to ensure AP is within 15 mm radius of IP.

Clinical research reveals that the predominant NCSE locations are in the frontal lobe followed by the temporal lobes. Specific electrode configurations from these predominant regions form the pEEG screening approach and may be displayed as visual cues (indicated positions or IP) on the tablet. At each configuration on the tablet, the operator may record thirty-second epochs to quantify the EEG patterns using feature classification algorithm. In practice, the operator may be directed by the tablet to place the 2-channel pEEG at a bihemispheric frontal lobe configuration (e.g. F3-F4-Cz) to detect any bilateral activity, indicating a generalized seizure episode. If bilateral activity is observed at the first location, the NCSE-specific approach may direct the operator to monitor two additional configurations symmetrical to the midsagittal plane (e.g. Fp1-Fp2-Cz and P3-P4-Cz). If only unilateral activity is observed at the first location, two subsequent hemisphere-specific configurations (e.g. left: F3-P3-Cz followed by T3-T5-M1 or right: F4-P4-Cz followed by T4-T6-M2) may be displayed to the operator for localizing the source of abnormal activity. In some embodiments, the feature classification performance will not be hampered considering the electrodes are within a 15 mm radius from the suggested IP.

In some embodiments, EEG signals will undergo time-frequency (TF) decomposition using discrete wavelet transform (DWT). The decomposition may segment the EEG into sub-bands using fourth order Daubechies wavelets to calculate approximate (A1-4) and detail (D1-4) coefficients for each sub-band. In some embodiments, the sub-band frequency ranges are: D1 (64 - 128 Hz), D2 (32 - 64 Hz), D3 (16 - 32 Hz), D4 (8 -16 Hz) and A4 (0 - 8 Hz). Extracted statistical parameters such as variance, standard deviation, and amplitude from the decomposed signals will be input to a naive Bayes (NB) classifier for feature classification. The NB classifier is based on the Bayesian theory that requires a minimal number of training datasets and has a high seizure feature classification accuracy of up to 98.65%.

When following the NCSE-specific approach, there may be expected scalp locations that are not easily reached by the electrode. In this situation, actions may be taken to allow for access to these scalp locations: 1) the tension-wire may be lengthened so the foot may reach a more acute electrode angle to accommodate perpendicular scalp surfaces, 2) different pivoting leg lengths may be printed and prepared to accommodate diverse head sizes, 3) improved pEEG housing mechanisms may be implemented to accommodate for limitations not addressed by adjusting tension-wire or leg length. In some embodiments, the device may implement an additional “knee” joint to improve pEEG dexterity and electrode contact.

As used in the specification and claims, the singular forms “a”, “an” and “the” include plural references unless the context clearly dictates otherwise. For example, the term “a sample” includes a plurality of samples, including mixtures thereof.

The terms “determining,” “measuring,” “evaluating,” “assessing,” “assaying,” and “analyzing” are often used interchangeably herein to refer to forms of measurement. The terms include determining if an element is present or not (for example, detection). These terms can include quantitative, qualitative or quantitative and qualitative determinations. Assessing can be relative or absolute. “Detecting the presence of” can include determining the amount of something present in addition to determining whether it is present or absent depending on the context.

The terms “subject,” “individual,” or “patient” are often used interchangeably herein. A “subject” can be a biological entity containing expressed genetic materials. The biological entity can be a plant, animal, or microorganism, including, for example, bacteria, viruses, fungi, and protozoa. The subject can be tissues, cells and their progeny of a biological entity obtained in vivo or cultured in vitro. The subject can be a mammal. The mammal can be a human. The subject may be diagnosed or suspected of being at high risk for a disease. In some cases, the subject is not necessarily diagnosed or suspected of being at high risk for the disease.

As used herein, the term “about” a number refers to that number plus or minus 10% of that number. The term “about” a range refers to that range minus 10% of its lowest value and plus 10% of its greatest value.

Example 1: Evaluation of a Single-Channel pEEG

In some embodiments, a single-channel pEEG functional device with essential hardware and software features has undergone testing that included: 1) evaluation of mechanism function for electrode-skin contact consistency and 2) circuit performance while acquiring posterior dominant rhythms from healthy adult subjects. Mechanical enclosure had a physical limiter to restrict the pivoting leg opening to 45° with respect to the central pen axis (as depicted inFIG.1B). An inter-electrode separation of 52.8 mm was allowed for reliable recordings while minimizing magnetic induction interference. The center of mass was closer to the base of the housing where the operator held the device, providing balance for short-term recordings. The enclosure was produced with Formlabs 3 stereolithography 3D printers. Circuit utilized a two-stage analog bandpass filter (1 - 34 Hz) and a microcontroller on a custom 15 x 45 (mm) six-layer PCB. An ultra-low noise instrumentation amplifier with a low 200 pA bias current and 100 dB CMRR was selected to maximize signal quality. The analog signals were sampled at 256 Hz. Data processing and signal acquisition was performed on a custom-designed iOS application. The application paired with the pEEG hardware via Bluetooth and displayed EEG signals on an iPad Pro 11-inch screen. Flexible real-time infinite impulse response (IIR) digital filters with low and high frequency cut-off were added to provide tunable filtering options. A real-time fast-Fourier transform (FFT) chart displayed power in the frequency domain to monitor signal noise level. Posterior dominant rhythm study was conducted on three untrained subjects who were directed to open and close their eyes via audio cues at 20-second intervals. The pEEG electrodes were applied at O2 for recording, T4 as ground and M2 as reference. Scalp locations were exfoliated with Nuprep cream and the gold-cup electrodes were applied using 10-20 conductive gel. The operator was able to hold the handheld pEEG for 4 minutes without discomfort. Anonymized data for 150 trials was post-processed in MATLAB to calculate alpha band power values between eye open and close events. Outcomes: Posterior dominant rhythms alpha power increase when the subjects closed their eyes, which is consistent with the existing EEG systems. The increase in power was verified by a one-sign tail test which reported statistical significance (p < 0.001).