• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    Graphene transistor system to measure electrophysiological signals. The object of the invention is based on flexible arrays of epicortical and intracortical field effect graphene transistors (gSGFETs), which can record infra-slow signals together with signals in a typical bandwidth of local field potentials. The object of the invention is based on the graphene transistor system to measure electrophysiological signals, comprising a processing unit, and at least one graphene transistor (gSGFET) that comprises graphene as channel material contacted by two terminals, to which a variable voltage source is attached at the drain and transistor source (gSGFET) terminals referring to the gate voltage, and at least one filter configured to acquire and divide the transistor signal into at least two bands frequency, low frequency band and high frequency band, in which the first and second signals are respectively amplified with a gain value. (Machine-translation by Google Translate, not legally binding)
    公开号:ES2759053A1
    申请号:ES201831068
    申请日:2018-11-06
    公开日:2020-05-07
    发明作者:Brunet Anton Guimerá；Codina Eduard Masvidal；Sanz Rosa Villa；Ariza Jose Antonio Garrido；Vila Xavier Illa；Vives María Victoria Sánchez
    申请人:Instituto De Investig Biomedicas August Pi Sunyer Idibaps；Consejo Superior de Investigaciones Cientificas CSIC；Centro de Investigacion Biomedica en Red de Enfermedades Hepaticas y Digestivas CIBEREHD；Institucio Catalana de Recerca i Estudis Avancats ICREA；Institut Catala de Nanociencia i Nanotecnologia ICN2；Consorcio Centro de Investigacion Biomedica en Red MP；
    IPC主号:
    专利说明:

    [0001]
    [0002]
    [0003]
    [0004] OBJECT OF THE INVENTION
    [0005]
    [0006] The object belongs to the technical field of physics and, more specifically, to the measurement of electrical signals.
    [0007]
    [0008] The object of the invention is intended for a device, and a method using this device, for the measurement and recording of certain electrophysiological signals.
    [0009]
    [0010] BACKGROUND OF THE INVENTION
    [0011]
    [0012] There is a great need for flexible, large-scale, high-density matrices with a wide electrophysiological recording bandwidth. Flexible, large-scale, high-density electrode arrays are state of the art. However, these matrices do not provide high fidelity records over the entire frequency bandwidth of electrophysiological signals.
    [0013]
    [0014] Electrophysiological signals exist over a wide range of frequencies and amplitudes: from minute signals of high amplitude such as propagated cortical depression to microvolt action potentials of amplitude and milliseconds in duration. Recording the full range of electrophysiological signals with high spatiotemporal resolution would be beneficial to unravel their relationship and interactions and to ensure that meaningful information is not lost.
    [0015]
    [0016] Most microelectrode arrays suffer from voltage drifts and oscillations that affect their recording quality of infralent signals, whose frequency is less than 0.1 Hz. This is so widely known that most recording systems include filters. high pass, to solve saturation problems that may arise due to basal drift, at the cost of excluding physiological and pathological information from being recorded.
    [0017] In recent years, there has been a particular resurgence of interest in fluctuations in brain activity at frequencies below 0.1 Hz, commonly known as very slow, ultra-slow, or infra-slow (ISA) activity. They have been suggested as indicators of brain states (eg, sleep, anesthesia, coma, wakefulness) and correlations were found with networks in a resting state as measured by functional magnetic resonance imaging. They can also contribute significantly to the high variability observed in physiological signals.
    [0018]
    [0019] There are some reported infrequent signals, such as cortical propagation waves called "propagated cortical depression (CSD)" that are only recorded at very low frequencies and therefore it is very difficult to study them on a regular basis due to the impairment of current electrodes. CSDs are defined as a slow spreading wave of depolarization of neurons and astrocytes followed by a period of suppression of brain activity and are often triggered when there is a brain episode such as in patients who have a stroke or trauma, as well as in migraines and other brain pathologies. Monitoring or detecting them could improve the diagnosis but above all influence therapeutic changes.
    [0020]
    [0021] Full band recordings, including the infrequent frequencies, have traditionally been performed with non-invasive techniques such as electroencephalogram (EEG) and magnetoencephalogram (MEG). However, its limited spatial resolution and averaged signal impose serious limitations; for example, EEG alone has not been sufficient for noninvasive detection of CDs. For these reasons, invasive electrophysiological techniques are the most commonly used to record infralent brain waves.
    [0022]
    [0023] Correct ISA recording requires the use of direct coupled amplifiers and extremely stable, low impedance electrodes. Traditionally, liquid filled glass micropipettes are used, which allow only one or few measuring points. For mapping with a higher spatial resolution, non-polarizable silver / silver chloride (Ag / AgCl) electrodes could be used, as they prevent charge build-up at the interface and therefore drift of voltage, however Due to the toxicity of silver, the use of such electrodes in humans as well as chronically in animals is not an option. This has encouraged the search for alternative materials with low impedance and drift, although none of them has been found capable of offering performance comparable to Ag / AgCl electrodes. Thus, ISA recordings in humans are currently performed with platinum electrodes, which hinder the correct detection of CSDs due to artifacts and transients. Importantly, basal drift in the form of baseline oscillations at infrequent frequencies makes it difficult to determine its "true" characteristics, such as amplitude or waveform, since any high pass filter used to eliminate such Effects will alter the shape of the signal.
    [0024]
    [0025] Another intrinsic limitation of microelectrode technology is due to the relationship between the impedance of the microelectrode and the input impedance of the recording equipment ( Z'e and Z 'a, respectively).
    [0026]
    [0027] The registered signal (Vín) is determined by the voltage divider formed by both impedances:
    [0028]
    [0029] V sigd) Z'a ( f)
    [0030] vini f) = arm Z'a ( n + Z'e ( f) (1)
    [0031]
    [0032] the Eq. (1) implies that when Z 'a is not substantially greater than Z ' e, the recorded signal will be attenuated and out of phase with respect to Vsig. Even using high input impedance amplifiers, for 50 µm diameter gold microelectrodes, an attenuation of more than 50% is expected. It is important to note that the Zá >>Z'e requirement to have a voltage gain equal to 1 is compromised when the area of the electrode is reduced, due to the inverse relationship between the impedance of the electrode and its area, resulting in filtering high pass of recorded signals.
    [0033]
    [0034] Therefore, reducing the size of the electrodes to achieve a higher spatial resolution causes the intrinsic high pass filtering of ISA due to the increased impedance of the associated electrode.
    [0035]
    [0036] Invasive optical techniques such as calcium imaging are used to monitor ISA, but even today they have serious problems solving high activity. frequency for a large number of neurons and their intrinsic need for indicators limits their translation to the clinic. Therefore, there is still a technique to measure signal registers that include large-scale infra-low frequencies and spatiotemporal resolution in a potentially implantable, non-toxic and clinical format.
    [0037]
    [0038] As an alternative to commonly used electrode technology, recording neural signals with field effect transistors (FETs) offers several advantages including that they are less sensitive to ambient noise thanks to their intrinsic voltage-current amplification, as they can be easily multiplexed. . However, difficulties in combining high gate capacitance and high mobility in silicon transistors on flexible substrates have historically hampered their use for in vivo recording . Liquid gate graphene based field effect transistors (gSGFETs) have been proposed to potentially overcome the above drawbacks. Graphene's flexibility allows gSGFETs to be included in ultra-soft and flexible substrates without loss of performance, while its wide electrochemical window and biocompatibility allows direct contact with biological fluids and tissues and guarantees safe operation in in vivo conditions. Furthermore, the two-dimensional nature of graphene impacts the highest possible ratio of surface to volume, making graphene highly sensitive to surface charges. Importantly, the transconductance frequency response of a gSGFET is flat over a wide bandwidth including low frequencies.
    [0039]
    [0040] Furthermore, graphene-based field effect transistors (g-SGFETs) have been extensively investigated as potential biosensors for various analytes, as in WO2011004136A1 where a sensor is disclosed to detect the presence of at least one biological molecule and a method for the production of such a sensor comprising a lithographed graphene structure, at least two electrical contacts arranged in contact with the lithographed graphene structure to determine a conductivity; and at least one linker attached to at least a portion of the lithographed graphene structure, wherein at least one linker has a binding affinity for at least one biological molecule.
    [0041] DESCRIPTION OF THE INVENTION
    [0042]
    [0043] The present invention addresses the need for large-scale, high-density, flexible matrices with a wide electrophysiological recording bandwidth. The object of the invention is based on a graphene field effect transistor (gSGFETs) preferably an array of field effect graphene transistors (gSGFETs) that are capable of recording infrared signals together with signals in typical bandwidth of the local field potentials. The graphene field effect transistor (gSGFETs) is preferably placed in epicortical and intracortical positions.
    [0044]
    [0045] The current invention simultaneously overcomes the challenges remaining in the prior art by providing greater stability arising from graphene's electrochemical inertia, as well as exceeding signal attenuation due to the impedance divider present in electrode recording systems by use of a transistor as a recording element.
    [0046]
    [0047] The graphene field effect transistor (gSGFETs) of the present invention is manufactured using the flexible substrate to overcome the difficulty in conforming to the geometry of various biological structures, hence the graphene field effect transistor (gSGFETs) it is preferably flexible. Also, when arranged in an array, the array is designed in an extensible manner such that the transistors can be scaled from micro to macro sizes as needed with various types of electrical contacts, such as those that sit on the surface of the tissue. (as opposed to penetrating).
    [0048]
    [0049] Therefore, the graphene transistor system for measuring electrophysiological signals of the invention encompasses a process unit, and at least one graphene transistor (gSGFET) spanning graphene as channel material contacted by two terminals, to which a variable voltage source is connected at the drain and transistor source terminals (gSGFET) referring to the gate voltage, and to which at least one filter is connected (a low pass filter (LPF) with de 104 [V / A] configured to generate a filtered low-pass band with a frequency set between 0Hz and 0.16 Hz or a band-pass filter (GMP) with a gain of 106 [V / A] configured to generate a band filtered with a frequency between 0.16 Hz and 10 kHz) configured to acquire and divide the transistor signal into at least two frequency bands, low frequency band and high band frequency; the first and second signals being respectively amplified with a gain value.
    [0050]
    [0051] The method and associated apparatus of the invention address the aforementioned needs in the art by providing amplification of the signals as well as the ability to measure the transfer curve of the transistor at the recording site. This allows choosing the best point of operation for the transistor and applying a calibration methodology (current to voltage conversion of the recorded signal) that ensures high-fidelity recording over a wide bandwidth.
    [0052]
    [0053] One of the main applications of the object of the invention is to monitor brain waves throughout the bandwidth; both in research and clinical implementations and in neurology. The same advantages exist for applications to other biological systems outside the brain, such as the heart, kidneys, stomach, cranial nerves, and other regions. The flexibility and versatility of graphene transistor arrays allow different applications and implementations ranging from subdural, epidural, or intracortical devices to other locations in the brain, cranial and peripheral nerves, heart, blood vessels, spinal cord, and other biological structures or locations. non-invasive electroencephalogram-like.
    [0054]
    [0055] DESCRIPTION OF THE FIGURES
    [0056]
    [0057] To complement the description made and in order to help a better understanding of the characteristics of the invention, a set of figures is represented, according to the example of the preferred implementation, as an integral part of the description where, by way of illustration and Not limiting, the following is represented.
    [0058]
    [0059] Figures 1a-1g.- Represent: technology and characterization of a matrix of field effect graphene transistors. 13 A schematic of a common gate mode polarized graphene transistor. 1b: Microscopy images of the active area of the 4x4 gSGFET matrices and that of the 15 intracortical channels. 1c: A photograph of the neural device. 1d: Steady state characterization of a 100x50-pm2 gSGFETs matrix in phosphate buffer (10mM) and with a drain-source voltage (Vds) of 50mV.
    [0060] 1e A graph showing the transfer curves of the gSGFETs, current drain-source (Ids) vs gate-source voltage (Vgs), along with the mean (dark curves) and the standard deviation (light curves). The inserted box plot shows the dispersion of the neutral load point (central line, median; box limits, upper and lower quartiles). 1e A graph for the loss current (Igs) of all the gSGFETs in the matrix. 1f: A graph for the transfer curve (blue squares and line) and its first derivative (transconductance (gm), black line) of a gSGFET. 1g A graph of the frequency response at two different points on the transfer curve (e): Vgs smaller than the CNP (green), where gm is negative resulting in a signal inversion (180 ° phase); and Vgs greater than the CNP (orange), where gm is positive and therefore results in non-inversion (0 ° phase). Regardless of the branch of the transfer curve where a gSGFET is polarized, the modulus of gm is similar to the steady state value for a wide bandwidth ( ~ 0 - 1 kHz).
    [0061]
    [0062] Figures 2a-2d.- They show a preferred implementation of the invention incorporating a gSGFET, the personalized electronic circuit and the post-processing methodology, as well as examples of the registered signals. 2a, Scheme of the gSGFETs registration system and post-processing methodology. The custom electronic circuit is used to perform in vivo characterization (transfer curve) and to record the transistor current in the low pass band (LPF) and band pass band (BPF). From the combination of the two signals and taking into account the current to voltage conversion, the wide band signal ( V sig) is obtained. 2b, Electrophysiological records obtained with an epicortical matrix during the induction of four events (blue highlight). From top to bottom: signal in LPF current, signal in BPF current and signal converted to wide band voltage.
    [0063]
    [0064] Figure 3.- They show an exemplary implementation of the electrical circuit. a, Schematic of the electronic instrumentation that controls the polarization of the gSGFETs (Vgs, Vds) and amplifies in a different way the two bands mentioned above: LPF («0-0.16 Hz, gain = 104) and BPF (0.16 Hz-10 kHz, profit = 106). The electrical circuit is used to characterize the steady state behavior of the gSGFETs as well as the AC modulation of the graphene transistors.
    [0065]
    [0066] Figure 4.- Shows the calibration procedure of the current registers of the gSGFETs to recover the voltage signal to the door. a, Current registers of the gSGFETs of a sinusoidal signal at the gate of 10 Hz and 0.85 mV peak applied to through a reference electrode. The graphene transistors are biased at Vds = 50mV and Vgs = 250mV. b, Transfer curve of the same graphene transistors at Vds = 50mV. The dotted line indicates the voltage Vgs used in a. c, Voltage signal obtained by interpolation of the current signal (a) of each transistor in its corresponding transfer curve and after subtracting the Vgs offset.
    [0067]
    [0068] Figure 5.- Shows the mapping with graphene transistors of propagated cortical depressions. a, Under-low frequency signals recorded by a 4x4 gSGFETs matrix with 400 pm spacing (black lines) during a CSD event as illustrated in the upper left diagram. The contour line drawing shows the temporal differences between the onset of CSD versus the mean time illustrating the spatiotemporal course of CSD. b, Interpolated spatial maps showing the propagation of the same CSD event measured by the gSGFETs array. a, b Filtered registers high pass to 0.1 Hz (red lines in a and spatial voltage maps in b) are included to illustrate the loss of information in conventional microelectrode records.
    [0069]
    [0070] Figures 6a, 6b.- Show the in-depth profile of the voltage of infra-slow frequencies induced by the cortical depression propagated in the rat cortex. a, Design of a 15-channel intracortical device and ordered records of local field potentials. Low-low frequency records (black lines) during the occurrence of a CSD event. The striped lines have been interpolated from nearby transistors. b, Colorado maps of the time course of the infrequent voltage changes during a CSD at the depth of the rat cortex. a-b, The same 0.1 Hz filtered signal (red lines) and their corresponding spatio-temporal map have been included to illustrate the loss of information in conventional microelectrode records.
    [0071]
    [0072] PREFERRED EMBODIMENT OF THE INVENTION
    [0073]
    [0074] A first aspect of the invention is intended for a system for electrophysiological recording of infralent signals such as propagated cortical depression (CSD), ie those with a frequency less than 0.1Hz; The device comprises a processing unit associated or included in the device and at least one graphene transistor (gSGFET), preferably an array of graphene transistors, graphene comprising the channel material contacted by terminals of source and drain, with a reference as a gate terminal. This graphene transistor is connected to at least one low pass filter (LPF). The signal recorded in current is transformed into voltage using the Ids - Vgs transfer curve acquired at the beginning of the records.
    [0075]
    [0076] In an alternative implementation, at least one bandpass filter (BPF) is implemented either sequentially or in cascade together with a lowpass filter (LPF), both filters being configured so that the respective cutoff points have the same value.
    [0077]
    [0078] A gSGFETS is a device in which graphene is used as a channel material, contacted by two metal cables (source and drain terminals), and immersed in a solution with electrolytes where a reference electrode is used as a gate terminal ( Fig. 1A). Flexible probes containing matrices of gSGFETs were produced in both epicortical and intracortical designs. In particular, a 100 pm wide 4x4 matrix was designed for 50 pm long graphene channels for epicortical recordings, while a design consisting of a linear matrix of 15 graphene channels (80 pm wide, 30 pm long). ) was used for intracortical records (Fig. 1B). Both die designs were fabricated from a 10 pm thick polyimide layer coated on a 4 inch silicon wafer. The flexible gSGFET matrices were placed in zero insertion force connectors for interconnection with the recording electronics (Fig. 1C). The transfer curve, the drain current (I_ds) versus the gate source voltage (V_gs), of all the gSGFETs in each array was measured with a fixed drain source voltage (V_ds). The dispersion of the charge neutrality point (CNP = 243.6 ± 6.1 mV), which is the minimum of the transfer curve, indicates the homogeneity of the transistors (Fig. 1D). Importantly, since the bias of V_gs and V_ds is shared, the small CNP scatter allows near-optimal recording performance for all gSGFETs on the same device. Figure 1E shows the sum of the leakage current (I_gs) for all gSGFETs in the matrix, which is in the nA range throughout the voltage sweep, demonstrating good passivation layer insulation and negligible reactivity of graphene. In addition, the transconductance frequency response (gm) of a gSGFET, which indicates the efficiency of the signal coupling ((I_ds) / (V_gs)), was measured, obtaining constant values over a wide bandwidth including the inflating frequencies (Fig . 1F-G). The negative gm for the values of VGS lower than CNP results in an inversion (180 ° phase) of the measured signals; for VGS values higher than CNP the signal phase is preserved.
    [0079]
    [0080] The device of the invention was compared to conventional high-pass filtered logs, for this the propagation of the events of propagated cortical depression (CSD) was mapped using a 4x4 gSGFET epicortical matrix and then compared with what is observed in logs conventional high pass filters (Fig. 5a-b). Recording of the entire CSD event with the gSGFET matrix reveals that while the onset of negative change is similar for all gSGFETs, there is much more variety in the subsequent recovery, with some transistors exhibiting a second negative change with greater amplitude than the first. This effect can also be observed in the last frames (corresponding to 80 s and 90 s) of the spatial maps of the gSGFET recordings (Fig. 5b) where recovered and still depressed brain areas coexist. Importantly, this information is lost in conventional microelectrode records, where only the onset of CSD is observed due to the high-pass filter in the recording electronics. The following results refer to a sample of 10 CSDs collected in the somatosensory cortex from two different subjects: we found that the average duration of CSD events is 47.24 ± 7.65 s and a speed of propagation of 7.68 ± 1.35 mm / min, according to the literature that defines CSDs as infralent brain waves.
    [0081]
    [0082] To further illustrate the potential of the device of the invention and taking advantage of the design versatility offered by this technology, a linear array of 15 gSGFETs spanning the entire depth of the cortex was designed (Fig. 6A). From the ordered recording or the spatiotemporal stress map (Fig. 6B), you can see how CSD occurs throughout the depth of the cortex. These results highlight the ability of the device of the invention to reveal the rich pattern of infralent signals in the cortex; in this particular case, a transition from a long to a shorter surface depolarization is clearly observed preceded and followed by hyperpolarization in the deeper layers. The origin of such an effect is not well understood and will be the target of other research, taking advantage of the proven ability of gSGFET technology to monitor ISA with high spatial resolution.
    [0083] In a second aspect of the invention, a method is provided for recording infralent brain signals, with infrared signals being those with a frequency value below 0.1 Hz. Propagated Cortical Depression (CSD) was chosen to illustrate the capabilities of the object of the invention to record in a wide bandwidth. Experimentally, two craniotomies were performed on the left hemisphere of Isoflurane-anesthetized Wistar rats: a larger craniotomy on the primary somatosensory cortex, where the epicortical device was placed, and a smaller one on the frontal cortex, where 5 mM KCl was applied locally. to induce CSD (Fig. 2B). A customized electronic circuit allowed us to simultaneously record in two frequency bands: low-pass filtered band (LPF, "0 0.16 Hz) and filtered band-pass band (BPF, 0.16 Hz-10 kHz) with different gains (104 and 106 respectively) to avoid amplifier saturation due to the high amplitude of the CSD signal. In a first set of experiments, we recorded the LPF and BPF current signals with an epicortical matrix of gSGFET during the induction of CSD events (Fig. 2C). The graphene transistors were polarized in the electron hole conduction regime, that is, VGS <CNP (GM negative); therefore, the recorded LPF and BPF current signals are reversed with respect to the voltage signal that occurs at the gate. The LPF signal shows the very slow event of the CSD while the BPF signal corresponds to the potential of the local field, revealing the silencing of the activity typical of propagated cortical depression. After the sum of the LPF and BPF signals and then transforming the current into a voltage signal (using the I_ds-VGS transistor transfer curve acquired in vivo before the start of the recordings), the band electrophysiological signal can be obtained wide (see Fig. 2 a, c). In each CSD event a small positive change of 1-2 mV generally precedes depression, immediately after which a steep negative change ("-20 mV) can be observed, which slowly recovers over the next few minutes. The silencing of high frequency activity associated with CSD and its progressive recovery is shown in the voltage waveform and spectrogram in Figure 2d.
    权利要求:
    Claims (7)
    [1]
    1. Graphene transistor system for electrophysiological signal measurements, comprising:
    to. a processing unit, and
    b. at least one graphene transistor (gSGFET) comprising graphene as the channel material contacted by two terminals, the device being characterized by having connected to the graphene transistor (gSGFET):
    to. a variable voltage source to the drain terminals and graphene transistor source (gSGFET) referred to the gate voltage, and b. at least one filter configured to acquire and separate the transistor signal into at least two frequency bands, high and low frequency bands, where the first and second signals are respectively amplified with a gain value.
    [2]
    2. Graphene transistor system for measurements of electrophysiological signals according to claim 1 where the filter is configured to generate:
    to. a low-pass filtered band with a frequency range of 0Hz to 0.16Hz, and
    b. a filtered band-pass band with a frequency range of 0.16 Hz to 10 kHz.
    [3]
    3. Graphene transistor system for measurements of electrophysiological signals with a wide bandwidth according to claim 2, where the low-pass filter (LPF) and the band-pass filter (BPF) have different gains; 104 * [V / A] and 106 [V / A] respectively.
    [4]
    4. Method for electrophysiological signal measurements using the graphene transistor system of any of claims 1-3, the method being characterized by comprising:
    to. separate an input signal into low and high frequency signals by means of a filter,
    b. bond the heavy low and high frequency signals for their corresponding gain, and
    c. transforming the current signal into voltage according to the intrinsic gain of the transistor.
    [5]
    5. Method according to claim 4, where the gain value of the amplification is different for each signal.
    [6]
    The method according to claim 4, wherein the transformation to a voltage signal is performed by means of interpolation using the Ids - Vgs transfer curve of the graphene transistor.
    [7]
    7. Method according to claim 6, where the graphene transistor ds - Vgs transfer curve is generated with a fixed drain-source voltage value (V_ds).
    类似技术:
    公开号 | 公开日 | 专利标题
    Masvidal-Codina et al.2019|High-resolution mapping of infraslow cortical brain activity enabled by graphene microtransistors
    ES2555382T3|2015-12-30|Electrodes and electrode positioning arrangement for fetal electrocardiogram detection
    FI126093B|2016-06-30|Arrangement and method for conducting electrode measurements
    Virtanen et al.1998|Replicability of MEG and EEG measures of the auditory N1/N1m-response
    KR101007558B1|2011-01-14|A flexible, multi-channel microelectrode for recording laboratory animal EEG and method for recording laboratory animal EEG using the same
    TW200300664A|2003-06-16|Electrodynamic sensors and applications thereof
    CN103393420A|2013-11-20|High-density active flexible electrode array and signal conditioning circuit thereof
    JP5069003B2|2012-11-07|Multi electrode
    Botter et al.2013|A novel system of electrodes transparent to ultrasound for simultaneous detection of myoelectric activity and B-mode ultrasound images of skeletal muscles
    Duun-Henriksen et al.2015|EEG signal quality of a subcutaneous recording system compared to standard surface electrodes
    US20130338529A1|2013-12-19|Bioelectric signal measurement apparatus
    Young et al.2006|A comparison of subdermal wire electrodes with collodion-applied disk electrodes in long-term EEG recordings in ICU
    Kotecha et al.2009|Time, frequency and volumetric differences of high-frequency neuromagnetic oscillation between left and right somatosensory cortices
    Fatoorechi et al.2015|A comparative study of electrical potential sensors and Ag/AgCl electrodes for characterising spontaneous and event related electroencephalagram signals
    KR20150001225A|2015-01-06|Electrode sensor for measuring of skin impedance of personal authentication, and skin impedance measurement device having the same
    Liu et al.2018|Intraoperative monitoring of neuromuscular function with soft, skin-mounted wireless devices
    Morikawa et al.2013|Compact wireless EEG system with active electrodes for daily healthcare monitoring
    Li et al.2016|Single probe for real-time simultaneous monitoring of neurochemistry and direct-current electrocorticography
    Vieira et al.2017|Changes in tibialis anterior architecture affect the amplitude of surface electromyograms
    Howells et al.2018|Tracking small sensory nerve action potentials in human axonal excitability studies
    Svärd et al.2010|Design and evaluation of a capacitively coupled sensor readout circuit, toward contact-less ECG and EEG
    ES2759053B2|2020-10-08|Graphene transistor system for measuring electrophysiological signals.
    Li et al.2016|Development and application of a microfabricated multimodal neural catheter for neuroscience
    Dong et al.2017|Flexible ECoG electrode for implantation and neural signal recording applications
    Kumaragamage et al.2015|A new low-noise signal acquisition protocol and electrode placement for electrocochleography | recordings
    同族专利:
    公开号 | 公开日
    WO2020094898A1|2020-05-14|
    ES2759053B2|2020-10-08|
    EP3879582A1|2021-09-15|
    CN113366653A|2021-09-07|
    US20210345930A1|2021-11-11|
    JP2022511125A|2022-01-28|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    GB2471672B|2009-07-07|2015-12-09|Swansea Innovations Ltd|Graphene biosensor|
    法律状态:
    2020-05-07| BA2A| Patent application published|Ref document number: 2759053 Country of ref document: ES Kind code of ref document: A1 Effective date: 20200507 |
    2020-10-08| FG2A| Definitive protection|Ref document number: 2759053 Country of ref document: ES Kind code of ref document: B2 Effective date: 20201008 |
    优先权:
    申请号 | 申请日 | 专利标题
    ES201831068A|ES2759053B2|2018-11-06|2018-11-06|Graphene transistor system for measuring electrophysiological signals.|ES201831068A| ES2759053B2|2018-11-06|2018-11-06|Graphene transistor system for measuring electrophysiological signals.|
    PCT/ES2019/070728| WO2020094898A1|2018-11-06|2019-10-28|System of graphene transistors for measuring electrophysiological signals|
    EP19881753.8A| EP3879582A1|2018-11-06|2019-10-28|System of graphene transistors for measuring electrophysiological signals|
    JP2021549923A| JP2022511125A|2018-11-06|2019-10-28|Graphene transistor system for measuring electrophysiological signals|
    CN201980072941.7A| CN113366653A|2018-11-06|2019-10-28|Graphene transistor system for measuring electrophysiological signals|
    US17/313,469| US20210345930A1|2018-11-06|2021-05-06|Graphene transistor system for measuring electrophysiological signals|
    [返回顶部]