DEVICE AND METHOD FOR RECEIVING BIOSIGNAL
20230073663 · 2023-03-09
Inventors
Cpc classification
H04B13/005
ELECTRICITY
A61B5/7246
HUMAN NECESSITIES
A61B5/7214
HUMAN NECESSITIES
A61B5/725
HUMAN NECESSITIES
International classification
Abstract
Disclosed are a biosignal receiving device and a method thereof. The biosignal receiving device used in a communication system using a human body as a medium includes a receiving electrode unit including a plurality of receiving electrodes, an input selection unit including two MUXs for selecting one of the plurality of receiving electrodes, and that output biosignals received by the selected electrodes, a filter that removes noise included in the biosignals and output filtered signals from which the noise is removed, a differential amplifier that amplifies a difference between the filtered signals and output amplified signals, a CDR circuit that generates a data signal and a clock signal from the amplified signals and outputs the data signal and the clock signal, and a controller that output selection signals for selecting one of the plurality of receiving electrodes, based on the data signal and the clock signal.
Claims
1. A biosignal receiving device used in a communication system using a human body as a medium, comprising: a receiving electrode unit including a plurality of receiving electrodes for receiving a biosignal received from the human body; an input selection unit including a first MUX for selecting a first electrode from among the plurality of receiving electrodes and a second MUX for selecting a second electrode different from the first electrode from among the plurality of receiving electrodes, and configured to output a first biosignal received by the first electrode and a second biosignal received by the second electrode; a filter configured to remove noise included in the first biosignal and the second biosignal, and output a first filtered signal and a second filtered signal from which the noise is removed; a differential amplifier configured to amplify a difference between the first filtered signal and the second filtered signal and to output a first amplified signal and a second amplified signal; a CDR circuit configured to generate a data signal and a clock signal from the first amplified signal and the second amplified signal, and to output the data signal and the clock signal; and a controller configured to output a first selection signal for selecting the first electrode from among the plurality of receiving electrodes and a second selection signal for selecting the second electrode from among the plurality of receiving electrodes to the input selection unit, based on the data signal and the clock signal.
2. The biosignal receiving device of claim 1, wherein the controller includes: a correlation value detector configured to detect a correlation value of the biosignal based on the data signal and the clock signal and to output the correlation value; and an electrode pair selector configured to generate the first selection signal and the second selection signal based on the clock signal and the correlation value.
3. The biosignal receiving device of claim 2, wherein the correlation value detector compares a preamble of a transmitting signal transmitted from a transmitting device included in a communication system using the human body as the medium with a preamble of the biosignal to derive the correlation value.
4. The biosignal receiving device of claim 3, wherein, when specific electrodes among the plurality of electrodes are selected as the first electrode and the second electrode, and the correlation value exceeds a predetermined threshold correlation value, the specific electrodes are finally selected as the first electrode and the second electrode.
5. The biosignal receiving device of claim 1, further comprising: a reference voltage level detector configured to determine whether a level of the biosignal is equal to or greater than a level of a reference voltage based on the first amplified signal, and to output a pulse signal to the controller based on the determination result.
6. The biosignal receiving device of claim 5, wherein the controller generates, based on the pulse signal, a result signal indicating a result of determining whether the biosignal has the level greater than or equal to the reference voltage, and outputs the result signal to the electrode pair selector.
7. The biosignal receiving device of claim 6, wherein the electrode pair selector generates the first selection signal and the second selection signal based on the correlation value and the result of the determining.
8. The biosignal receiving device of claim 5, wherein a reference voltage level detector includes: an amplifier configured to amplify and output a voltage applied to a node between a supply voltage and a ground; and a comparator configured to compare the first amplified signal with a reference voltage output from the amplifier and to output the pulse signal corresponding to the comparison result.
9. The biosignal receiving device of claim 8, wherein the pulse signal has a high level when the level of the first amplified signal is greater than or equal to the reference voltage, and has a low level when the level of the first amplified signal is less than the reference voltage.
10. A biosignal receiving method comprising: selecting a first electrode and a second electrode from among a plurality of receiving electrodes; receiving a biosignal from the first electrode and the second electrode; detecting a correlation value with respect to the biosignal; and determining whether a level of the biosignal is greater than or equal to a level of a reference voltage, and wherein the correlation value is based on a correlation between a preamble of a transmitting signal transmitted to a human body providing the biosignal and a preamble of the biosignal.
11. The biosignal receiving method of claim 10, further comprising: determining whether the correlation value is detected for all of receiving electrode combinations generated from the plurality of receiving electrodes.
12. The biosignal receiving device of claim 11, further comprising: when the correlation value is not detected for all of the receiving electrode combinations, reselecting the combination of the first electrode and the second electrode from receiving electrode combinations that are not selected among the receiving electrode combinations.
13. The biosignal receiving device of claim 10, further comprising: determining whether the correlation value is greater than or equal to a predetermined threshold correlation value.
Description
BRIEF DESCRIPTION OF THE FIGURES
[0019] The above and other objects and features of the present disclosure will become apparent by describing in detail embodiments thereof with reference to the accompanying drawings.
[0020]
[0021]
[0022]
[0023]
[0024]
[0025]
[0026]
[0027]
[0028]
[0029]
DETAILED DESCRIPTION
[0030] Hereinafter, embodiments of the present disclosure will be described clearly and in detail such that those skilled in the art may easily carry out the present disclosure.
[0031] The terms used in the specification are provided to describe the embodiments, not to limit the inventive concept. As used in the specification, the singular terms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms “comprises” and/or “comprising” when used in the specification, specify the presence of steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other steps, operations, elements, components, and/or groups thereof
[0032] In the specification, the term “first and/or second” will be used to describe various elements but will be described only for the purpose of distinguishing one element from another element, not limiting an element of the corresponding term. For example, without departing the scope of the inventive concept, a first element may be referred to as a second element, and similarly, a second element may be referred to as a first element.
[0033] Unless otherwise defined, all terms (including technical and scientific terms) used in the specification should have the same meaning as commonly understood by those skilled in the art to which the inventive concept pertains. The terms, such as those defined in commonly used dictionaries, should not be interpreted in an idealized or overly formal sense unless expressly so defined herein. The same reference numerals represent the same elements throughout the specification.
[0034]
[0035] Referring to
[0036] Each of the first to n-th receiving electrodes 110_1, 110_2, . . . , and 110_n included in the receiving electrode unit 100 may receive a signal provided from the transmitting device through the human body. Each of the first to n-th receiving electrodes 110_1, 110_2, . . . , and 110_n may provide the received signal to the first MUX 210 and the second MUX 220 included in the input selection unit 200.
[0037] The input selection unit 200 may select some signals from among a plurality of signals provided from the receiving electrode unit 100. The first MUX 210 and the second MUX 220 included in the input selection unit 200 may independently perform a selection operation. However, the first MUX 210 and the second MUX 220 included in the input selection unit 200 cannot select a signal received from the same receiving electrode. For example, when the first MUX 210 selects a receiving signal received from the first receiving electrode 110_1, the second MUX 220 cannot select the receiving signal received from the first receiving electrode 110_1.
[0038] A receiving electrode selected by the first MUX 210 from among the first to n-th receiving electrodes 110_1, 110_2, . . . , and 110_n may correspond to a first electrode of the biosignal receiving device 10, and a receiving electrode selected by the second MUX 220 from among the first to n-th receiving electrodes 110_1, 110_2, . . . , 110_n may correspond to a second electrode of the biosignal receiving device 10. In the biosignal receiving device 10, the first electrode may be in contact with human skin. The second electrode may be used as a ground of the biosignal receiving device 10. A first receiving signal Si of the first electrode selected by the first MUX 210 and a second receiving signal S2 of the second electrode selected by the second MUX 220 may be provided to the filter 300.
[0039] The filter 300 may perform a filtering operation on the first receiving signal S1 and the second receiving signal S2. For example, the filter 300 may pass or block only signals within a specific bandwidth from the first receiving signal Si and the second receiving signal S2. The filter 300 may cancel noise through the filtering operation on the first receiving signal Si and the second receiving signal S2. A first filtered signal F1 obtained by filtering the first receiving signal Si and a second filtered signal F2 obtained by filtering the second receiving signal S2 may be provided to the differential amplifier 400.
[0040] The differential amplifier 400 may amplify and output a difference between a positive input and a negative input of the differential amplifier 400. In other words, the differential amplifier 400 may amplify the difference between the first filtered signal F1 and the second filtered signal F2 and may output the amplified signal. The first filtered signal F1 may be provided to the positive input of the differential amplifier 400, and the second filter circuit F2 may be provided to the negative input of the differential amplifier 400.
[0041] The first filtered signal F1 may correspond to a voltage induced in the first electrode, and the voltage induced in the first electrode may be generated by an electric field formed between the human body and the receiving electrode. Also, the second filtered signal F2 may correspond to a voltage induced in the second electrode, and the voltage induced in the second electrode may be generated by an electric field formed between the second electrode and the ground of a ground surface. The voltage induced in the second electrode may be used as a reference voltage for amplifying the voltage induced in the receiving electrode. The differential amplifier 400 may provide a first amplified signal Al and a second amplified signal A2 to the CDR circuit 500.
[0042] The CDR circuit 500 may separate a data signal DT and a clock signal CL from the first amplified signal Al and the second amplified signal A2. The CDR circuit 500 may provide the data signal DT and the clock signal CL to the controller 600.
[0043] The controller 600 may determine optimal receiving electrode combinations for human body communication with respect to the first to n-th receiving electrodes 110_1, 110_2, . . . , 110_n included in the receiving electrode unit 100, based on the data signal DT and the clock signal CL. The controller 600 may allow the input selection unit 200 to select optimal receiving electrode combinations, by providing a first selection signal SEL1 and a second selection signal SEL2 based on the determination result of the optimal receiving electrode combinations to the input selection unit 200.
[0044] In an embodiment according to the present disclosure, the biosignal receiving device 10 may allow to selectively operate a receiving electrode capable of providing an optimal signal quality among the plurality of receiving electrodes 110_1, 110_2, . . . , 110_n, thereby improving the performance of the human body communication system. A method of selecting the optimal receiving electrode combinations in the biosignal receiving device 10 according to the present disclosure and the configuration of the controller 600 for this will be described in detail with reference to
[0045]
[0046] The correlation value detector 610 of the controller 600 may receive the data signal DT and the clock signal CL from the CDR circuit 500 (refer to
[0047] For example, when the signal transmitted from the transmitting device is transmitted to the biosignal receiving device 10 without attenuation or error, the preamble of the transmitting signal and the preamble of the receiving signal may have the same data stream, and in this case, the correlation value may be a value of 100. In contrast, when the signal transmitted from the transmitting device is transmitted to the biosignal receiving device 10 with attenuation or error, the preamble of the transmitting signal and the preamble of the receiving signal may have different data streams, and in this case, the correlation value may have a value greater than or equal to 0 and less than 100. The correlation value detected by the correlation value detector 610 may be provided to the electrode pair selector 620.
[0048] The electrode pair selector 620 may select an optimal electrode pair based on the clock signal CL provided from the CDR circuit 500 and the correlation value provided from the correlation value detector 610. The optimal electrode pair means a receiving electrode combination capable of exhibiting optimal communication performance among the first to n-th receiving electrodes 110_1, 110_2, . . . , 110_n included in the receiving electrode unit 100 (refer to
[0049]
[0050] There are 12 receiving electrode pairs (the first electrode and the second electrode) that may occur in the embodiment 10a in which the four receiving electrodes 110_1, 110_2, 110_3, and 110_4 illustrated in
[0051]
[0052] For example, in
[0053] In the embodiment 10a in which the four receiving electrodes 110_1, 110_2, 110_3, and 110_4 illustrated in
[0054] Based on these results, the electrode pair selector 620 may select an optimal electrode pair based on the correlation value. As an example, the electrode pair selector 620 may derive a correlation value associated with the number of all 12 cases that may occur in the embodiment 10a in which the four receiving electrodes 110_1, 110_2, 110_3, and 110_4 illustrated in
[0055] Also, in an embodiment according to the present disclosure, the biosignal receiving device 10 may recognize data received after the preamble of the receiving signal received by the receiving electrode combination having the maximum correlation value as data transmitted by the transmitting device.
[0056]
[0057] The reference voltage level detector 700 may additionally determine whether a level of the receiving signal is greater than or equal to a reference level using an output of the differential amplifier 400. In
[0058] The reference voltage level detector 700 may receive a first amplified signal Al from the differential amplifier 400, and may generate a pulse signal PU based thereon. The reference voltage level detector 700 may provide the generated pulse signal PU to the controller 600 (refer to
[0059]
[0060] The pulse determiner 630 may determine a goodness degree of a level of the receiving signal based on the pulse signal PU provided from the reference voltage level detector 700 (refer to
[0061] The pulse determiner 630 may provide a determination result signal RS including information on the determination result with respect to the goodness degree of the level of the receiving signal to the electrode pair selector 620. Accordingly, the electrode pair selector 620 may select a combination of receiving electrodes that may exhibit the optimal communication performance in the biosignal receiving device 20, based on the correlation value derived from the correlation value detector 610 and the result of whether the signal level provided from the pulse determiner 630 is good.
[0062]
[0063] The comparator 710 may compare the receiving signal with the reference voltage to compare an amplitude of the receiving signal with a level of the reference voltage. A first amplified signal Al provided from the differential amplifier 400 (refer to
[0064] The amplifier 720 may amplify a voltage applied to a second node N2 positioned between a supply voltage VDD and the ground GND. The reference voltage level detector 700 may generate the pulse signal PU based on the comparison result derived from the comparator 710, and the generated pulse signal PU may be provided to the controller 600 (refer to
[0065]
[0066] There are 12 receiving electrode pairs (the first electrode and the second electrode) that may occur in the embodiment 20a in which the four receiving electrodes 110_1, 110_2, 110_3, and 110_4 illustrated in
[0067]
[0068] For example, in
[0069] In the embodiment 20a in which the four receiving electrodes 110_1, 110_2, 110_3, and 110_4 illustrated in
[0070] As illustrated in
[0071]
[0072] In operation S110, the biosignal receiving device 10 or 20 (refer to
[0073] In operation S120, the biosignal receiving device 10 or 20 may receive a biosignal from an arbitrarily selected electrode pair. The biosignal refers to a signal transmitted from a receiving device included in a human body communication system to an electrode pair using the human body as a medium. The noise in the biosignal may be removed through the filter 300 (refer to
[0074] In operation S130, the biosignal receiving device 10 or 20 may detect a correlation value with respect to a signal received from an arbitrarily selected electrode pair based on the data signal DT and the clock signal CL. The correlation value may correspond to a match rate between the preamble of the transmitting signal transmitted from the transmitting device and the preamble of the receiving signal received by the biosignal receiving device 10 or 20.
[0075] In operation S140, the biosignal receiving device 10 or 20 may detect whether a level of a signal received from an arbitrarily selected electrode pair is greater than or equal to a level of a reference voltage. In
[0076] In operation S150, the biosignal receiving device 10 or 20 may determine whether a determination on the correlation value is performed and a determination as to whether it is greater than or equal to the reference voltage is performed with respect to electrode pairs that may be generated from all the receiving electrodes included in the biosignal receiving device 10 or 20. When determination is not made with respect to all possible receiving electrode pairs, a procedure may proceed to operation S160. When determination is made with respect to all possible receiving electrode pairs, a procedure may proceed to operation S170.
[0077] In operation S160, the biosignal receiving device 10 or 20 may select one of the remaining combinations except for the previously selected electrode pair.
[0078] When another electrode pair is selected, the procedure may return to operation S120.
[0079] In operation S170, the biosignal receiving device 10 or 20 may select a final electrode pair capable of optimizing communication performance, and the procedure ends.
[0080] In the present specification, in a communication system using the human body as a medium, the biosignal receiving device 10 or 20 is disclosed that the plurality of receiving electrodes 110_1, 110_2, . . . , and 110_n operate as a path of the receiving signal in the receiving electrode unit 100 (refer to
[0081] According to an embodiment of the present disclosure, the device and method for receiving the biosignal may overcome performance degradation due to attenuation of a waveform of a receiving signal and may improve signal receiving performance.
[0082] The above description refers to embodiments for implementing the present disclosure. Embodiments in which a design is changed simply or which are easily changed may be included in the present disclosure as well as an embodiment described above. In addition, technologies that are easily changed and implemented by using the above embodiments may be included in the present disclosure. While the present disclosure has been described with reference to embodiments thereof, it will be apparent to those of ordinary skill in the art that various changes and modifications may be made thereto without departing from the spirit and scope of the present disclosure as set forth in the following claims.