Abstract: The terminal includes a touch panel including first electrodes arranged in a first direction and second electrodes arranged in the second direction intersecting the first direction, a display panel attached to the touch panel and to display an image, and a processor to control the touch panel and the display panel. In a measuring mode, the processor is configured to: apply a driving signal to the touch panel, the touch panel being configured to form an electric field and/or magnetic field when the driving signal is applied, and determine body composition of a user based on a sensing signal output from the touch panel in accordance with eddy current, the eddy current being induced to a body of the user by the electric field and/or magnetic field formed around the touch panel.

Abstract: According to an aspect, an active matrix substrate of an X-ray imaging panel includes: an active matrix substrate having a pixel region including a plurality of pixels; and a scintillator that converts X-rays projected onto the X-ray imaging panel to scintillation light. The plurality of pixels include respective photoelectric conversion elements. The active matrix substrate further includes a first planarizing film that covers the photoelectric conversion elements, is formed from an organic resin film, and has a plurality of first contact holes and a first wiring line that is formed in the first contact holes and in a layer upper than the first planarizing film and connected to the photoelectric conversion elements within the first contact holes.

Abstract: Methods and systems for improving nerve stimulation are disclosed which relate to shaping characteristics of the stimulation field such as by using different geometries and locations of stimulation. In embodiments, systems and methods are provided to improve selective modulation of specific targeted neural substrate, while minimizing the activation of adjacent non-targeted nervous tissue. While aspects of the disclosed technologies can be applied to any part of the central and peripheral nervous systems for treatment various disorders and providing symptom relief to provide for therapy related to pelvic floor disorders such as overactive bladder.

Abstract: A monitor device and a base plate and an ostomy system comprising a monitor device and a base plate is disclosed. The base plate comprising: a top layer; an electrode assembly; and a monitor interface configured for connecting the base plate to a monitor device. An axial distance along an axial direction between a proximal facing edge of a coupling part and a contact surface on the distal side of the top layer is a first axial distance. The first axial distance being less than a second axial distance between a distal facing edge of the monitor device and a proximal facing side of the monitor device, such that upon connecting the base plate to the monitor device the proximal facing side of the monitor device contacts the contact surface to force a first connection parts to contact a first terminal element.

Abstract: The electronic device includes a pad module and a main module. At least part of the patch module is attached to a user to obtain a bio-signal of the user. The pad module includes a first housing and a plurality of first electrodes disposed in the first housing. The main module is configured to record the bio-signal of the user that is transferred through the pad module. The main module includes a second housing that is coupled with the first housing in a first direction. The main module also includes a plurality of second electrodes disposed in the second housing. The plurality of second electrodes are configured to make electrical contact with the plurality of first electrodes. The main module further includes a plurality of magnetic bodies disposed in the second housing to correspond to positions of the plurality of second electrodes.

Abstract: Apparatuses for detecting swallowing disorders and methods for using same are provided. In a general embodiment, the apparatuses include a disposable sensor base and a sensor that is received by the disposable sensor base. The sensor base includes a sensor interface having a predetermined cut-away shape and a directionally-keyed mating surface. The sensor includes a handle portion having a shape that corresponds to the predetermined shape of the sensor interface, a support portion configured to be received by the directionally-keyed mating surface when the sensor is inserted into the sensor interface, and electronics configured to collect data sensed by the sensor. The apparatuses of the present disclosure can be attached to a patient's neck to detect and/or diagnose swallowing disorders during a swallowing test.

Abstract: A body physiotherapy machine contains a conductive sphere member and a body configured to output electric physiotherapy energy to the conductive sphere member. The conductive sphere member is held by a user to contact his/her discomfort or acupuncture points so as to comfort the user and to enhance metabolism by ways of the electric physiotherapy energy, thus maintaining health easily.

Abstract: An electrocardiogram information dynamic monitoring method and dynamic monitoring system.

Abstract: A bioelectrode (1) includes: a main electrode film (3); a nonpolarizable electrode film (4) disposed on one surface of the main electrode film (3); and a conductive gel film (5) disposed on the opposite surface of the nonpolarizable electrode film (4) from the main electrode film. The nonpolarizable electrode film (4) is constituted by an electrode film that contains supported silver chloride, the supported silver chloride including (i) a support and (ii) silver chloride supported on the support.

Abstract: The present invention is intended to provide a gel sheet having a formulation providing an adhesive force on the skin side suitable for the skin (i.e., a gel having a low adhesive force and being able to withstand a tip pressure of a terminal and the like), and concurrently having a sufficient adhesive force against an electrode element on the side opposite to the skin side. The present invention is a gel sheet having a laminated structure of a layer A and a layer B, characterized in that the storage elastic modulus of the layer A at 23° C. and 10 Hz is 12,000 to 40,000 Pa, and the storage elastic modulus of the layer B at 23° C. and 10 Hz is 2,000 to 10,000 Pa.

Abstract: The present invention provides a thin and flexible device and method of use thereof for wound treatment and infection control. The integrated surface stimulation device may comprise wireless stimulation system in a disposable and/or reusable flexible device for widespread use in multiple therapeutic applications. The invention would be situated on the skin surface of a patient and would be activated so as to reduce the overall occurrence of infections and/or increase wound healing rates. As provided, the device will comprise an integrated power supply and pre-programmable stimulator/control system on a flexible polymeric substrate layer with areas of stimulating electrodes, applied using techniques such as those found in additive manufacturing processes. The device is especially valuable in treating biofilm-based infections.

Abstract: An extended wear electrocardiography patch is provided. An integrated flexible circuit includes a single piece of material and has an upper end and a lower end opposite the upper end. A mirror image of the upper end extends from at least a portion of one side of the upper end and folds over the upper end. One circuit trace is positioned on the upper end and one circuit trace is positioned on the lower end. Electrical pads are located on a contact surface of the upper end and on an outward facing surface of the mirror image of the upper end. An electrocardiographic electrode is positioned on the contact surface of the upper end and another electrocardiographic electrode is positioned on a contact surface of the lower end. A battery is directly adhered to the outward facing surface of the mirror image of the upper end.

Abstract: This system is a network of sensor nodes with multiple sensors at each node. The nodes are used in combination with a wearable garment to enable multiple types of data to be combined together to produce a fuller picture of a body's physiological state; such as during physical therapy. In addition, the system utilizes acoustic imaging to measure muscle activation. The system transmit this data to a host computer to visualize various data comparisons.

Abstract: The invention provides a neck-worn sensor that is a single, body-worn system that measures the following parameters from an ambulatory patient: heart rate, pulse rate, pulse oximetry, respiratory rate, temperature, thoracic fluid levels, stroke volume, cardiac output, and a parameter sensitive to blood pressure called pulse transit time. From stroke volume, a first algorithm employing a linear model can estimate the patient's pulse pressure. And from pulse pressure and pulse transit time, a second algorithm, also employing a linear algorithm, can estimate systolic blood pressure and diastolic blood pressure. Thus, the sensor can measure all five vital signs along with hemodynamic parameters. It also includes a motion-detecting accelerometer, from which it can determine motion-related parameters such as posture, degree of motion, activity level, respiratory-induced heaving of the chest, and falls.

Abstract: An electrocardiogram information processing method and workstation system. The method includes receiving electrocardiogram data output by multiple devices; performs data analysis on the electrocardiogram data, and generating report data and stores same; receiving a report data query by a user, queries corresponding report data according to a user ID of the user, and generating report result list for display and output; receiving a selection by the user, and obtaining selected report data according to the selection; receiving a report data consultation request input by the user; obtaining a user ID of an associated user corresponding to the user ID according to the report data consultation request, and sending the report data to a user equivalent of the associated user according to the user ID of the associated user; and receiving a consultation result feedback data sent by the user equivalent of the associated user.

Abstract: An external defibrillator comprises an energy storage module, a discharge circuit, electrodes, a measurement circuit to sense contemporaneously a first ECG signal from a first vector and a second ECG signal from a second vector, and a subsequent ECG signal, and a processor. The processor is configured to multiply values of the first ECG signal with values of the second ECG signal to derive a product waveform, detect, in the product waveform, peaks that exceed a detection threshold, measure durations of time intervals between pairs of successive detected peaks, compute a heart rate of the patient from the measured durations of the time intervals, determine from the subsequent ECG signal whether a shock criterion is met, and when met, control the discharge circuit to discharge a stored electrical charge to deliver a shock to the patient. A communication module is configured to transmit the computed heart rate.

Abstract: Systems, devices, methods, and kits for monitoring one or more physiologic and/or physical signals from a subject are disclosed. A system including patches and corresponding modules for wirelessly monitoring physiologic and/or physical signals is disclosed. A service system for managing the collection of physiologic data from a customer is disclosed. An isolating patch for providing a barrier between a handheld monitoring device with a plurality of contact pads and a subject is disclosed.

Abstract: A repositionable surface electrode for patient monitoring includes an active electrode layer having a top surface and a bottom surface and a leadwire connected to the active electrode layer. A first substrate has a top side, a bottom side, and a hole there through. The first substrate is positioned below the bottom surface of the active electrode layer such that the hole is aligned with the active electrode layer. An electrode gel channel is configured to conduct potentials from the patient's skin to the active electrode layer, the electrode gel channel extending through the hole in the first substrate. A silicone layer on the bottom side of the first substrate, avoiding the hole and the electrode channel, is configured to adhere the surface electrode to the patient's skin and to be removed from the patient's skin without becoming saturated with skin cells such that the electrode repositionable on the patient.

Abstract: A portable device for measuring a bioimpedance-related property of tissue includes a plurality of electrodes arranged in a pattern on a surface and associated software for measuring bio-impedance related data of localized regions of tissue and calculate health-related parameters based on the measured data. These calculated parameters may be representative of muscular health of the localized tissue region.

Abstract: The present invention provides systems and methods for detection and diagnosis of concussion and/or acute neurologic injury comprising a portable headwear-based electrode array and computerized control system to automatically and accurately detect cortical spreading depression and acute neurological injury-based peri-infarct depolarization (CSD/PID). The portable headwear-based electrode system is applied to a patient or athlete, and is capable of performing an assessment automatically and with minimal user input. The user display indicates the presence of CSD/PID, gauges its severity and location, and stores the information for future use by medical professionals. The systems and methods of the invention use an instrumented DC-coupled electrode/amplifier array which performs real-time data analysis using unique algorithms to produce a voltage intensity-map revealing the temporally propagating wave depressed voltage across the scalp that originates from a CSD/PID on the brain surface.

Abstract: An electronic device for long-term adhesion to a mammal includes a housing with an electronic component. The electronic device may include a first wing and a second wing, each being integrally formed with the housing. An electrode is positioned on a bottom surface of each of the wings, the electrodes electrically connected to the electronic component. An adhesive layer is provided for adhesion to a surface of the mammal. The adhesive layer may cover a portion of the bottom surfaces of the wings but generally does not cover the electrode or a bottom surface of the housing. A method of applying an electronic device to a mammal includes removing first and second adhesive covers from first and second wings of the electronic device to expose an electrode and an adhesive coated on a bottom surface of each wing.

Abstract: A system and method for using electroencephalographic (EEG) signals to monitor brain function, preferably detect occurrence of traumatic brain injury (TBI) to screen, assess, and potentially provide mitigating treatment to improve short and long term adverse outcomes of mild TBI (mTBI) and TBI. The system and method provides a readily available tool to assist in accurate and objective assessment of subjects with TBI, immediately at the point of injury (POI), during transportation, or upon arrival at a care facility, that preferably is applicable without advanced training or expertise.

Abstract: Embodiments of the present disclosure generally relate wearable patches having rigid inserts. The rigid insert is positioned adjacent to one or more connectors, such as studs for receiving sockets to distribute the force transferred to a patient when reconnecting a socket to the stud. The rigid insert may be sized to maintain flexibility in areas of the wearable patch. An optional adhesive layer may be applied to the wearable patch adjacent the rigid insert to reduce the likelihood of delamination of the wearable patch.

Abstract: The present invention relates to a physiological recording electrode, and, more particularly, to an EEG (electroencephalography) recording electrode that can be used without the need for numerous steps in preparing the subject's skin and the electrode itself. The invention further relates to a surface feature or penetrator with a size and shape which that will not bend or break, which limits the depth of application, and/or anchors the electrode or other device during normal application; and a packaging system comprising a well and electrolytic fluid for maintaining a coating of said electrolytic fluid on the surface feature or penetrator.

Abstract: In an aspect, the present disclosure discloses a medical sensor to be connected to a monitoring device for vital sign monitoring. The medical sensor includes a flexible circuit layer having an electrode pattern, a foam layer laminated on the flexible circuit layer, a bonding layer sandwiched between the flexible circuit layer and the foam layer to bond the foam layer with the flexible circuit layer, and a gel sponge disposed on and electrically connected to the electrode pattern through the foam layer and the bonding layer. The area of the bonding layer is smaller than the area of the foam layer. A part of the foam layer adjacent the perimeter is not covered by the bonding layer, and not bonded to the flexible circuit layer by the bonding layer to provide the medical sensor enough conformability to a body.

Abstract: Embodiments of devices and methods for evaluating tissue are disclosed. In one embodiment, a method for measuring a characteristic of a tissue may include passing a current through the tissue, measuring a signal corresponding to the voltage resulting from passing the current through the tissue, analyzing current passed through the tissue and resulting voltage to determine the electrical characteristics of the tissue; and analyzing the electrical characteristics of the tissue to determine a status of the tissue. Disposable sensors are disclosed.

Abstract: An electrode assembly includes a first surface to be placed adjacent a person's skin and a second surface including a plurality of reservoirs of conductive gel. The plurality of reservoirs of conductive gel are disposed on sections of the electrode assembly that are at least partially physically separated and may move at least partially independently of one another to conform to contours of a body of a patient. The electrode assembly is configured to dispense an amount of the electrically conductive gel onto the first surface in response to an activation signal and to provide for a defibrillating shock to be applied to the patient through the amount of the electrically conductive gel.

Abstract: An electronic sensor device has one or more sensor electrodes and one or more electrical conductors printed on a substrate. Textile layers are attached on either side of the substrate with access to the electrical conductors provided by a conductive snap assembly. The substrate can be a TPU (thermoplastic polyurethane) film. The sensor can be a biosensor, and the biosensor is attached to a compression textile, such as a compression shirt, and electrically interconnected using printed conductive ink interconnects to a conductive snap button.

Abstract: A bioelectric device includes multiple first reservoirs and multiple second reservoirs joined with a planar substrate. Selected ones of the multiple first reservoirs include a reducing agent, and first reservoir surfaces of selected ones of the multiple first reservoirs are proximate to a first substrate surface. Selected ones of the multiple second reservoirs include an oxidizing agent, and second reservoir surfaces of selected ones of the multiple second reservoirs are proximate to the first substrate surface.

Abstract: An electrical venous stimulation apparatus comprising a powered signal generator, the signal generator configured to generate a specified electrical output signal. The apparatus also includes a plurality of electrodes in electrical communication with the signal generator and configured, to be placed in electrical communication with a subject, The electrical output signal sent to the subject, includes an output voltage, electrical current, and waveform that changes with time in a preprogrammed repeating cycle. The output voltage, electrical current, and waveform are configured to elicit a physiological response that stimulates a plurality of peripheral nerves in the subject, activates a venous muscle pump mechanism in one or more limbs of the subject, and non-invasively alter the physiology of target vein(s), wherein the target vein(s) is caused to distend under the surface of the subject's skirt.

Abstract: A patient worn sensor assembly for detecting, recording, and communicating patient vital signs includes several structural features that can provide increased signal quality, reduction in signal noise, increased patient comfort, increased reliability, and increased adhesion to a patient's skin. The patient worn sensor can track vital sign information such as blood pressure, body temperature, respiratory rate, blood oxygenation, heart rhythm (via ECG), heart rate, blood glucose level, and hydration (bio-impedance) levels. The sensor can also track and record additional information about patients, including patient movement, activity, and sleep patterns.

Abstract: Apparatus and method are provided to collect and analyze phonocardiogram (PCG) an electrocardiogram (ECG) waveforms. In one novel aspect, the PCG and ECG waveforms are collected from wearable devices. In one embodiment, the wearable device collects heartbeat waveforms by attaching the device to the patient for a long period and sends the collected waveforms to a receiver through a wireless network. In one embodiment, an acoustic seal layer is attached to the wearable device to reduce the body movement noises and environmental noises. In another novel aspect, an analysis method compares received patient's current PCG/ECG waveform with historic data. In one embodiment, the historic data are stored in a cloud-based database.

Abstract: The present invention relates to novel lip/cheek probes for detection of pulse-based differences in light absorbence across the vascularized tissue of a lip or cheek of a patient. These probes are fabricated to provide signals to estimate arterial oxygen saturation, and/or to obtain other photoplethysmographic data. The present invention also relates to a combined probe/cannula. The present invention also relates to other devices that combine a pulse oximeter probe with a device supplying oxygen or other oxygen-containing gas to a person in need thereof, and to sampling means for exhaled carbon dioxide in combination with the novel lip/cheek probes. In certain embodiments, an additional limitation of a control means to adjust the flow rate of such gas is provided, where such control is directed by the blood oxygen saturation data obtained from the pulse oximeter probe.

Abstract: A wearable device comprising a data logger, a motion sensor, and a memory component is disclosed for recording motion data. The motion sensor may detect movement of the device when worn by a subject, and the memory component may store motion data from the motion sensor. A casing may be included for retaining the data logger and providing a contact barrier between at least part of the data logger and the subject. The contact barrier may substantially prevent contact contamination of at least part of the data logger while the device is worn by the subject for collection and storage of subject-specific motion data. The casing is controllably accessible to release the data logger in a substantially uncontaminated state.

Abstract: The invention concerns a multi-electrode patch for abdominal electrophysiological detection. The patch has a flexible substrate interconnecting multiple electrodes and a module unit for removably engaging with an electronic readout device for detecting a maternal and/or fetal electrophysiological signal from the electrodes. The module has a mechanical module unit for removable mechanical engagement with a housing of the readout device, and an electrical module unit for making an electrical connection from the electrodes to the readout device. Engaging the patch with the readout device comprises engaging both the mechanical module unit and the electrical module unit. The patch may be flexible in a manner that allows variation in the relative positioning between the electrodes. The patch and/or electronic readout device may comprise a security device for communication of an authentication code.

Abstract: An emergency cardiac and electrocardiogram (ECG) electrode placement device is disclosed herein. The emergency cardiac and electrocardiogram (ECG) electrode placement device incorporates electrical conducting materials and elastic material into a pad that is applied to a chest wall of a patient, which places multiple electrodes in the appropriate anatomic locations on the patient to quickly obtain an ECG in a pre-hospital setting.

Abstract: Provided is a biological electrode tool including an electrode portion (10) attached to a human body to acquire a biological signal, and a lead portion (20) for externally leading out the biological signal from the electrode portion (10). The entire areas of the upper and lower surfaces of the electrode portion (10) are covered with a nonwoven fabric (30) except for a portion that contacts the living body (13). The entire areas of the upper and lower surfaces of the lead portion (20) are also covered with nonwoven fabric except for an external lead-out end portion (14). The full circumferential peripheries of the nonwoven fabrics (30) on the upper and lower surfaces of the electrode portion (10) and the lead portion (20) are bonded except for the portion that contacts the living body (13) and the external lead-out end portion (14). Neither the electrode (11) of the electrode portion (10) nor a thin-film lead wire (21) of the lead portion (20) are exposed.

Abstract: An identification device to be adhered to the skin of an animal having a top side and a bottom side comprising: a substrate with a printable surface with biocompatible pigment displaying visually discernible information disposed on the top side of the substrate; biocompatible adhesive on bottom side of substrate; an electronic component below the top side of the substrate comprising an electronic device with the ability to send, receive, and store information; and a carrier sheet, wherein the substrate and the adhesive are flexible, elastic, biocompatible, breathable, and comprised of material allowing for transmission of moisture and vapor at a rate that allows the device stay affixed to the skin for its pre-determined useful timeframe to slow down deterioration of components below substrate and to minimize skin irritation.

Abstract: The invention includes conductive polymeric coatings, medical device, coating solutions and methods of making the same. A coating solution for forming a conductive polymer layer can include a conductive monomer, at least one photoreactive component comprising an anionic photoreactive cross-linking agent or an anionic photoreactive hydrophilic polymer, and a solvent. A medical device can include an electrode and an electrically conductive coating disposed over the electrode. The electrically conductive coating can include a reaction product of the conductive monomer and the at least one photoreactive component. Other aspects are included herein.

Abstract: A device includes a capacitive sensor having a hydrogel structure that includes a first surface and a second surface. A first electrode is provided at the first surface of the hydrogel structure, the first electrode including a network of conductive nanoparticles extending into the hydrogel structure. A second electrode is provided at the second surface of the hydrogel structure.

Abstract: An electrode package includes an electrode pad to be attached to a subject, the electrode pad having a gel layer, a lead wire having one end electrically coupled to the gel layer, and a packaging cover having an opening portion, the opening portion being sealed such that the electrode pad and a part of the lead wire are housed inside the packaging cover. A sealing width in at least a part of a section where the packaging cover is sealed together with the lead wire is narrower than a sealing width in a section where only the packaging cover is sealed. A sealing apparatus is configured to seal the packaging cover.

Abstract: Articles and methods of making articles are described. In one embodiment, an electrode is described, comprising an ionically-conductive hydrogel layer comprising a first major surface and opposing major surface. The electrode further comprises a discontinuous primer layer disposed on the first major surface ionically-conducting hydrogel layer and an electrically conductive member or a connector component thereof, in contact with the first major surface of the ionically-conducting hydrogel layer. In another embodiment, an article is described comprising a hydrogel layer comprising a first major surface and opposing major surface; a discontinuous hydrophobic primer layer disposed on the first hydrogel layer; and a hydrophobic adhesive or hydrophobic backing bonded to the primer and discontinuous hydrophobic primer layer of the hydrogel.

Abstract: Method and apparatus for providing reliable blood oxygen (SaO2) and heart rate measurements includes a chemical energy heating source in conjunction with a harness that is adapted to secure the chemical energy heating source and a pulse oximeter probe proximate to a region of the body which is to be warmed prior to measurement. Preferably, the chemical energy heating source is in the form a mixture including a metal powder, which releases heat at a predetermined rate via oxidation of the metal powder when exposed to the atmosphere. The apparatus may be designed to be reusable or disposable and can be used in a transmission or reflectance mode, or both.

Abstract: An electrode sensor is provided. The electrode sensor can include a conductive sensor area that is at least partially covered by hydrogel. The hydrogel can be conductive and adhere to skin. A receptacle can form an open container surrounding the conductive sensor area and the hydrogel.

Abstract: The present invention relates to hydrogels which may be used to encapsulate or entrap live cells. The invention further relates to methods for transporting live cells which are encapsulated or entrapped within hydrogels from a first location to a second location. The invention further relates to method of treating a wound, disease or tissue injury, e.g. an ocular injury or a damaged ocular surface in a subject using a hydrogel comprising corneal stem cells. The hydrogels used in such methods may be ones which have been transported from a first location to a second location.

Abstract: A measurement patch device may change length according to somatotype of a user, and may be joined with another measurement patch device integrally according to the need of different physiological lead measurement. Moreover, the two joined measurement patch devices may rotate with respect to each other, such that multi-channel or multi-lead physiological signal may be measured to save measurement time of physiological signal.

Abstract: An electronic sticker assembly includes a first electronic sticker comprising an upper surface, a lower surface, and first one or more conductive connection dots on the upper surface, a first adhesive layer on the first electronic sticker and comprising a first window. The first window is positioned to expose the first one or more conductive connection dots. A second electronic sticker on the first adhesive layer includes a lower surface and one or more second conductive connection dots on the lower surface. The first conductive connection dots on the upper surface of the first electronic sticker are in contact with the one or more second conductive connection dots on the lower surface of the second electronic sticker through the first window in the first adhesive layer.

Abstract: An aspect of the subject technology/invention of the present disclosure includes electrode structures or elements/components that have (e.g., present) fractal and/or self-complementary shapes or structures, e.g., on a surface. Such shapes or structures can be pre-existing. The electrodes can be made of any suitable material. The electrodes may function or operate or be used as a “seed” structure to incorporate or receive a material or materials useful for lattice assisted nuclear reactions and/or cold fusion processes.

Abstract: A multi-axis defibrillator electrode band includes a stretchable band having a first end and a second end; and at least one pair of defibrillation electrodes embedded in the stretchable band between the first end and the second end, wherein a first electrode in the electrode pair is disposed opposite a second electrode in the electrode pair to define a conduction channel from the first electrode to the second electrode when the band is in a usage position for a defibrillation event.

Abstract: An electrocardiogram (ECG) electrode patch (10) system (50) for use in a magnetic resonance (MR) environment includes a flexible patch material (12) configured for attachment to human skin, and a plurality of electrodes (20). The electrodes (20) Care attached to the patch material (12) and configured to sense a plurality of ECG signals with different amplitudes across pairs of electrodes in at least two different directions.