Object recognition method and object recognition apparatus

Abstract

The present disclosure provides an object identification method and an object identification apparatus. Specifically, an object identification method capable of quickly and accurately identifying viruses and the like is provided. The object identification method according to an aspect of the present disclosure includes: supplying an object dispersed in a solvent to a microchannel; applying an AC (alternating current) voltage to a measurement electrode provided at the microchannel while the object passes through the microchannel, and measuring an AC characteristic of the object. Subsequently, a combined impedance and a phase are determined by using the measured AC characteristic, and the object is identified by using the determined combined impedance and phase.

Description

[0001] Cross-reference to related applications

[0002] This disclosure claims priority and benefit to Japanese Patent Application No. 2022-021902, filed with the Japan Patent Office on February 16, 2022, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to an object recognition method and an object recognition device. Background Technology

[0004] Methods for detecting viruses, microorganisms, or viroids (hereinafter also referred to as viruses, etc.) include polymerase chain reaction (PCR) and immunochromatography. On the other hand, methods for sensing viruses, etc., by electrical measurement have been studied as other detection methods. Examples of electrical measurement methods include dispersing the virus, etc., to be detected in water and electrically detecting these viruses, etc., as particles. To prevent infectious diseases and their spread, it is desirable to detect viruses, etc., in various environments (e.g., indoor environments, livestock sheds, and outdoor environments). The aforementioned electrical measurement methods are suitable for sensing in such environments (Japanese Unexamined Patent Application Publication Nos. 2020-202824 and 2020-098211). Summary of the Invention

[0005] As stated above, in order to prevent infectious diseases and their spread, a technology is needed for rapidly and accurately identifying viruses and the like in the environment. In view of the above needs, the object of this disclosure is to provide an object identification method and object identification device capable of rapidly and accurately identifying viruses and the like.

[0006] An object identification method according to one aspect of this disclosure includes: supplying an object dispersed in a solvent to a microchannel; applying an AC (Alternating Current) voltage to a measuring electrode disposed in the microchannel as the object passes through the microchannel, and measuring the AC characteristics of the object; and determining a combined impedance and phase by using the measured AC characteristics, and identifying the object by using the determined combined impedance and phase.

[0007] An object identification device according to one aspect of the present disclosure includes: a microchannel through which an object dispersed in a solvent flows; a measuring electrode disposed at the microchannel; a measuring circuit configured to apply an AC voltage to the measuring electrode and measure the AC characteristics of the object when the object passes through the microchannel; and an object identification unit configured to determine a combined impedance and phase by using the measured AC characteristics, and to identify the object by using the determined combined impedance and phase.

[0008] According to this disclosure, an object identification method and object identification device capable of quickly and accurately identifying viruses and the like can be provided.

[0009] The above and other objects, features and advantages of this disclosure will be more fully understood from the detailed description given below and the accompanying drawings, which are given by way of illustration only, and should therefore not be considered as limitations on this disclosure. Attached Figure Description

[0010] Figure 1 A diagram is shown illustrating an embodiment of the configuration of the object recognition device according to the implementation scheme;

[0011] Figure 2 A flowchart illustrating the object identification method according to the implementation scheme is shown;

[0012] Figure 3 A diagram is shown to illustrate an embodiment of a method for identifying objects;

[0013] Figure 4 A diagram is shown to explain the AC characteristics of the object;

[0014] Figure 5 A diagram is shown to explain the AC characteristics of the object;

[0015] Figure 6 A diagram is shown to illustrate the use of a locked amplification method to measure AC characteristics;

[0016] Figure 7 A diagram is shown to illustrate the use of a locked amplification method to measure AC characteristics;

[0017] Figure 8 A top view is shown to illustrate another embodiment of the microchannel;

[0018] Figure 9 A top view is shown to illustrate another embodiment of the microchannel;

[0019] Figure 10 A cross-sectional view is shown to illustrate another embodiment of the microchannel;

[0020] Figure 11 A graph showing the AC characteristics measured using the locked amplification method is shown;

[0021] Figure 12 A chart showing the measurement results for various beads is displayed;

[0022] Figure 13 A graph showing the measurement results of a reference sample with virus size is displayed;

[0023] Figure 14 A graph showing the measurement results of a reference sample with virus size is displayed;

[0024] Figure 15 A graph showing the measurement results of a reference sample with virus size is displayed;

[0025] Figure 16 A graph showing the measurement results of T4 bacteriophage and baculovirus is presented;

[0026] Figure 17 A chart showing the measurement results of the influenza virus is displayed;

[0027] Figure 18 Charts showing the measurement results for various viruses are displayed;

[0028] Figure 19 A graph showing the measurement results for Pediococcus and Escherichia coli is presented;

[0029] Figure 20 A graph showing the measurement results for the measured sample and the reference sample is displayed;

[0030] Figure 21 A graph showing the measurement results of AC measurements performed when a DC bias voltage is applied to particles with negative surface charges is displayed.

[0031] Figure 22 A graph showing the measurement results of the ζ-potential is presented;

[0032] Figure 23 A graph showing the measurement results of the dielectric constant is shown; and

[0033] Figure 24 A graph showing the measurement results of the dielectric constant is presented. Detailed Implementation

[0034] In the following description, embodiments according to this disclosure will be described with reference to the accompanying drawings.

[0035] Figure 1 A diagram is shown illustrating an embodiment of the configuration of an object recognition device according to a specific implementation. (See diagram for example.) Figure 1As shown, the object identification device 1 according to this embodiment includes a microchannel 10, measuring electrodes 11a and 11b, a measuring circuit 12, and an object identification unit 13. The object identification device 1 according to this embodiment is used to identify objects to be measured (such as viruses, bacteria, microorganisms, etc.). It is worth noting that the object identification device 1 according to this embodiment can also identify objects other than viruses, bacteria, and microorganisms, as long as the object can be dispersed in a solvent.

[0036] Microchannel 10 is a channel (e.g., a flow path) through which an object 15 dispersed in a solvent passes. Microchannel 10 has a width such that only one object 15 can pass through it. By employing the above configuration, the AC (alternating current) characteristics of multiple objects 15 can be measured sequentially. That is, since multiple objects 15 pass through microchannel 10 sequentially, measurement circuit 12 can measure the AC characteristics of multiple objects 15 sequentially.

[0037] In this embodiment, an ionic liquid can be used as the solvent. Further, object 15 is a virus, bacteria, microorganism, etc. It is worth noting that object 15 can be any object other than a virus, bacteria, or microorganism, as long as the object can be dispersed in the solvent. Further, in this embodiment, a liquid other than an ionic liquid (e.g., an aqueous solution) can be used as the solvent. Further, the atmosphere can also be used as the medium, and in this case, object 15 can also be dispersed in the atmosphere.

[0038] The width of the microchannel 10 can be determined based on the size of the object 15 to be measured. For example, when the object 15 is a virus with a particle size (or particle diameter, such as average particle size or average particle diameter) of about 100 nm, the width of the microchannel 10 can be between 150 nm and 400 nm. Further, for example, when the object 15 is a bacterium with a particle size of about 1 μm, the width of the microchannel 10 can be between 1.5 μm and 4 μm.

[0039] Measuring electrodes 11a and 11b are disposed at the microchannel 10 and configured to apply an AC voltage to an object 15 passing through the microchannel 10. Figure 1 In the illustrated embodiment of the configuration, two measuring electrodes 11a and 11b are arranged to sandwich the microchannel 10 between the two measuring electrodes. However, the measuring electrodes 11a and 11b can be positioned close to the microchannel 10, or anywhere the measuring electrodes can apply an AC voltage to the object 15.

[0040] Measurement circuit 12 is configured to apply an AC voltage to measurement electrodes 11a and 11b, and to measure the AC characteristics of the object 15 as it passes through microchannel 10. Any circuit capable of measuring the AC characteristics of object 15 can be used for measurement circuit 12. Measurement circuit 12 is configured to apply an AC voltage to measurement electrodes 11a and 11b, the AC voltage having a frequency between several kHz and several GHz, preferably between 1 kHz and 100 MHz, and more preferably between 1 MHz and 10 MHz. For example, a lock-in amplifier can be used for measurement circuit 12. Details of the lock-in amplifier will be described later.

[0041] The object identification unit 13 is configured to determine (e.g., calculate) the combined impedance and phase using the AC characteristics measured by the measurement circuit 12, and to identify the object using the determined combined impedance and phase. In this embodiment, parameters corresponding to the resistive component, zeta potential, and dielectric constant of the object 15 can be determined using the combined impedance and phase, and the object 15 can be identified using the determined parameters corresponding to the resistive component, zeta potential, and dielectric constant. For example, the object identification unit 13 can be formed using a personal computer or the like.

[0042] Next, the object identification method according to this embodiment will be described. The object identification method according to this embodiment can be achieved by using... Figure 1 The object recognition device 1 shown in the figure is used to perform this function. Figure 2 A flowchart illustrating the object recognition method according to this embodiment is shown. Reference will be made below. Figure 1 and Figure 2 Describe the object identification method according to this implementation scheme.

[0043] To identify object 15, firstly, object 15 dispersed in a solvent is supplied to microchannel 10 (i.e., the object flows through microchannel 10) (step S1). Next, an AC voltage is applied to measuring electrodes 11a and 11b disposed on microchannel 10, and the AC characteristics of object 15 are measured as object 15 passes through microchannel 10 (step S2). For example, measuring circuit 12 applies an AC voltage to measuring electrodes 11a and 11b at a frequency not less than 1 kHz and not more than 100 MHz (hereinafter also referred to as between 1 kHz and 100 MHz). It is worth noting that in this embodiment, an AC voltage may also be applied continuously to measuring electrodes 11a and 11b in advance, and then object 15 dispersed in a solvent may be supplied to microchannel 10.

[0044] Next, object 15 is identified by using the measured AC characteristics (step S3). Specifically, the combined impedance and phase are determined by using the measured AC characteristics, and object 15 is identified by using the determined combined impedance and phase.

[0045] In this embodiment, parameters corresponding to the resistive component, zeta potential, and dielectric constant of object 15 can be determined by using combined impedance and phase, and object 15 can be identified by using the determined parameters corresponding to the resistive component, zeta potential, and dielectric constant. For example, as Figure 3 As shown, object 15 can be identified by mapping parameters corresponding to its resistive component, zeta potential, and dielectric constant onto a three-dimensional coordinate system, where each axis represents the resistive component, zeta potential, and dielectric constant, respectively. It is worth noting that the parameters corresponding to the resistive components are those corresponding to the dimensions of object 15. The parameters corresponding to the zeta potential are those corresponding to the surface potential of object 15. The parameters corresponding to the dielectric constant are those corresponding to the structure of object 15 (such as a spherical shell structure and a membrane structure) or to the material of object 15.

[0046] Object 15 has different dimensions, different surface potentials, and different structures depending on its type. Therefore, the resistive component, zeta potential, and dielectric constant of object 15 (which are parameters corresponding to the aforementioned dimensions, surface potentials, and structures) can be determined (e.g., calculated), and the parameters corresponding to the resistive component, zeta potential, and dielectric constant of object 15 can be mapped to, for example... Figure 3 The object is classified into group A, group B, and group C using the three-dimensional coordinate system shown. For example, by mapping the measurement results of various types of object 15 to... Figure 3 The data accumulated on the three-dimensional coordinate system shown can improve the accuracy of object 15 identification.

[0047] Furthermore, in this embodiment, the combined impedance and phase can be determined (e.g., calculated) using the method shown below. The object 15 (such as a virus) can be represented by an equivalent circuit including resistive and capacitive components. Therefore, when measuring the AC characteristics of the object 15, the following is obtained: Figure 4 The measurement waveform is shown. Specifically, as... Figure 4 As shown in the upper part, when an AC voltage is applied to the resistive component, an in-phase measurement waveform is obtained (i.e., a measurement waveform with the same phase as the AC voltage). Further, as... Figure 4 As shown in the lower part, when an AC voltage is applied to the capacitive component, a measurement waveform is obtained in which its phase is delayed by 90 degrees compared to the phase of the AC characteristic voltage.

[0048] Furthermore, the impedance Zr of the resistive component and the impedance Zc of the capacitive component can be expressed as follows: Figure 5 The vector diagram shown is used to represent this. Figure 5 In this context, the combined impedance Z can be represented by a combined vector of impedances Zr and Zc. Furthermore, the phase θ can be represented by the phase difference between the capacitive component and the resistive component. Thus, the combined impedance Z and phase θ can be determined.

[0049] Furthermore, in this embodiment, a lock-in amplifier can be used to extract the in-phase component corresponding to the AC characteristics, as well as the phase component offset from the in-phase component, and the combined impedance and phase can be determined by using the extracted in-phase and phase components. Subsequently, the object can be identified by using the time-varying characteristics of the combined impedance (i.e., the change of the combined impedance over time) and the time-varying characteristics of the phase (i.e., the change of the phase over time).

[0050] In other words, in this implementation scheme, it can be achieved by using [the method for...]. Figure 1 The lock-in amplifier of the measurement circuit 12 shown determines the combined impedance and phase. Figure 6 and Figure 7 A diagram is shown to illustrate the use of a lock-in amplifier to measure AC characteristics. Figure 6 The lock-in amplifier shown includes a sine wave generation circuit 21 and a measurement electrode 11 (with...). Figure 1 The measurement electrodes 11a and 11b shown correspond to each other, as do the mixer 22 and the low-pass filter (LPF) 23.

[0051] The sine wave generation circuit 21 generates a sine wave (AC voltage) and supplies the generated sine wave (AC voltage) to the measuring electrode 11. When the sine wave is supplied to the measuring electrode 11, the measured waveform Vs(t) of the object 15 is obtained. The obtained measured waveform Vs(t) is supplied to the mixer 22. Furthermore, the sine wave generated in the sine wave generation circuit 21 is also supplied to the mixer 22 as a reference waveform Vr(t). Since the measured waveform Vs(t) is a waveform reflecting the resistive and capacitive components of the object 15, the amplitude of the measured waveform Vs(t) is different from the amplitude of the reference waveform Vr(t), and the phase of the measured waveform Vs(t) is offset from the phase of the reference waveform Vr(t).

[0052] Mixer 22 multiplies the measured waveform Vs(t) by the reference waveform Vr(t). Low-pass filter 23 removes unwanted high-frequency components from the signal multiplied in mixer 22. The signal output from low-pass filter 23 can be represented as "X+iY", and the X and Y components of the signal are respectively compared with... Figure 7The real and imaginary parts on the complex plane are shown in Figure 30. That is, the X component is the in-phase component, and the Y component is the phase component. Subsequently, by using trigonometric methods, the... Figure 7 The X and Y components in the diagram 30 shown are converted (transformed) into the intensity R (corresponding to the combined impedance) and phase θ of the measured waveform Vs(t). Figure 7 Figure 31 shows the time-varying change in intensity R (combined impedance) after the transformation (conversion), and Figure 7 The diagram 32 shown illustrates the temporal change of phase θ after the transformation.

[0053] In this implementation scheme, it can be achieved by using Figure 7 The time-varying nature of the combined impedance R shown in Figure 31, and Figure 7 The temporal variation of phase θ, shown in Figure 32, is used to identify objects. Specifically, as... Figure 7 As shown in Figures 31 and 32, the values ​​of the combined impedance R and phase θ change when the object 15 passes through the microchannel 10. For example, the object can be identified by using the width W1 and amplitude A1 of waveform 33 with the changed combined impedance R, and the width W2 and amplitude A2 of waveform 34 with phase θ.

[0054] For example, the parameter corresponding to the ζ-potential of object 15 can be determined by using the width W1 of waveform 33 of combined impedance R. Further, the parameter corresponding to the resistive component of object 15 can be determined by using the amplitude A1 of waveform 33 of combined impedance R. Further, the parameter corresponding to the dielectric constant of object 15 can be determined by using waveform 34 of phase θ. When the parameter corresponding to the dielectric constant is determined, the phase θ is shifted by 90 degrees from the in-phase component.

[0055] It is worth noting that the equivalent circuit of object 15 (such as a virus) cannot necessarily be represented by a simple RC circuit (Resistor-Capacitor circuit). That is, in some cases, the impedance is complex. Therefore, in practice, impedance Zr (the real part of impedance) does not necessarily correspond to the R component, and impedance Zc (the imaginary part of impedance) does not necessarily correspond to the C component. For example, impedance Zr (the real part of impedance) can also have a capacitive component, and / or impedance Zc (the imaginary part of impedance) can also have a resistive component.

[0056] As explained above, in this embodiment according to the present disclosure, when object 15 passes through microchannel 10, the AC characteristics of object 15 are measured, and the combined impedance and phase are determined using the measured AC characteristics. Subsequently, object 15 is identified using the determined combined impedance and phase. Therefore, according to this embodiment of the present disclosure, an object identification method and object identification device capable of quickly and accurately identifying viruses can be provided. Further, in this embodiment according to the present disclosure, microchannel 10 has a width such that only one object 15 can pass through it at a time, allowing multiple objects 15 to be measured individually.

[0057] Furthermore, in this embodiment, in addition to object 15, a reference sample for calibration can also be dispersed in a solvent. When the reference sample is dispersed in a solvent in addition to object 15, object 15 can be accurately identified. That is, since the particle size, etc. (including zeta potential and dielectric constant) of the reference sample are known, the particle size, etc. of object 15 can be accurately measured by comparing the measurement results of object 15 with the measurement results of the reference sample. As a result, object 15 can be accurately identified. Furthermore, since object 15 and the reference sample can be measured under the same conditions (e.g., the same equipment, the same solvent, and the same electrode state), object 15 and the reference sample can be accurately measured. Furthermore, in this embodiment, since object 15 and the reference sample can be measured simultaneously, the measurement time can be reduced compared to the case where object 15 and the reference sample are measured separately.

[0058] When object 15 and reference sample are dispersed in a solvent, the solvent in which object 15 and reference sample are dispersed is supplied to microchannel 10, and the AC characteristics of object 15 are measured as object 15 passes through microchannel 10. Further, the AC characteristics of reference sample are measured as reference sample passes through microchannel 10. Subsequently, object 15 is identified based on the combined impedance and phase determined using the AC characteristics of object 15, and the combined impedance and phase determined using the AC characteristics of reference sample.

[0059] Furthermore, the shape of the microchannel 10 and the shapes of the measuring electrodes 11a and 11b in this embodiment are not limited to... Figure 1 The shape shown. Figures 8 to 10 Figures illustrating other embodiments of microchannels are shown. Figure 8 In the illustrated embodiment, a supply port 41a, a microchannel 42, and a discharge port 41b are formed on the substrate 40. The object dispersed in the solvent is supplied from the supply port 41a and subsequently passes through the microchannel 42 and is discharged from the discharge port 41b. Figure 8In the embodiment of the configuration shown, measuring electrodes 43a and 43b are formed in the portion of the substrate where the supply port 41a and discharge port 41b are formed (the portion of the surface that is different from the portion where the hole through which the solvent passes is formed). Figure 8 In the embodiment with the configuration shown, the measurement time may be increased because the AC characteristics can be measured while objects such as objects pass through the microchannel 42.

[0060] exist Figure 9 In the illustrated embodiment, a supply port 51a, a microchannel 52, and a discharge port 51b are formed on the substrate 50. The object dispersed in the solvent is supplied from the supply port 51a and subsequently passes through the microchannel 52 and is discharged from the discharge port 51b. Figure 9 In the embodiment with the configuration shown, measuring electrodes 53a and 53b are formed to sandwich a portion of the microchannel 52. Figure 9 In the embodiment with the configuration shown, since the measuring electrodes 53a and 53b are formed to sandwich a portion of the microchannel 52, the influence of the resistive and capacitive components of the microchannel 52 itself can be reduced, thus improving the S / N ratio.

[0061] exist Figure 10 In the embodiment with the configuration shown, the microchannel 61 is formed by forming a generally circular hole penetrating the substrate 60. That is, as Figure 10 As shown in the cross-sectional diagram, the microchannel 61 is formed by forming a hole penetrating the substrate 60, and the measuring electrodes 62a and 62b are respectively disposed on the upper and lower surface sides of the substrate 60. Figure 10 In the illustrated embodiment, the microchannel 61 can be easily formed through the substrate 60. It is worth noting that the shape of the microchannel is not limited to this embodiment. Figure 1 , Figure 8 , Figure 9 and Figure 10 The shape shown is shown. In other words, microchannels can have other shapes.

[0062] [Example]

[0063] The embodiments according to this disclosure will now be described.

[0064] First, a sample solution was prepared by mixing phosphate-buffered saline (154.0 mM NaCl, 5.6 mM Na₂PO₄, 1.07 mM KH₂PO₄), a surfactant (0.1% Tween 20 or Trinton-X), and a virus (10⁵ to 1,0¹⁰ virus / mL). For microchannels, a solution was prepared using... Figure 10The microchannels shown have pore diameters ranging from 100 nm to 4,000 nm. Further, in this embodiment, by using... Figure 6 The lock-in amplifier shown is used to measure the AC characteristics of the object (i.e., the virus). It is important to note that in the embodiments described below, a reference sample, etc., is also used instead of the virus.

[0065] The measurement conditions are as follows.

[0066] - Waveform: Sine wave

[0067] - Measurement frequency: 1kHz to 1MHz

[0068] - Applied voltage: 0.1V to 1V

[0069] -Applied pressure: 0.1 Pa to 1 Pa

[0070] It is worth noting that the pressure applied is the pressure applied when the solvent is supplied to the microchannel (i.e., when the solvent flows through the microchannel).

[0071] Figure 11 The temporal variations of the R component (combined impedance) and the phase component (phase θ) are shown, and these temporal variations are the results of measurements performed under the conditions described above. Figure 11 As shown, when the object (virus) passes through the microchannel, the amplitude values ​​in the graphs of the R component and phase component change. That is, the amplitude value in the R component graph decreases, while the amplitude value in the phase component graph increases. Subsequently, by using the method described above, through... Figure 11 The waveforms in the chart shown are used to determine the particle size (particle diameter) of the object.

[0072] Figures 12 to 20 The particle size distribution of the object as a measurement result is shown.

[0073] Figure 12 The measurement results for various beads are shown. It is worth noting that... Figure 12 The measurement results shown are for the case where an aqueous solution is used as the solvent. Furthermore, the measurement frequency is 5 kHz. Figure 12 In this study, samples with a wide range of particle sizes (particularly diameters ranging from 100 nm to 2,000 nm) were measured. Figure 12 As shown, particle size can be accurately measured for each sample.

[0074] Figure 13 Measurement results for a reference sample with virus size (i.e., approximately equal to the size of the virus) are shown. Figure 13In this study, reference samples with particle sizes (i.e., diameters) of 100 nm, 114 nm, 250 nm, 350 nm, and 500 nm were measured. Figure 13 As shown, the accuracy of the measurement results is 97% or higher for each reference sample, which means that the particle size of the reference sample can be measured accurately.

[0075] Figure 14 Measurement results for a reference sample with virus size are shown. Figure 14 In this study, reference samples with particle sizes (i.e., diameters) of 930 nm (CPC 1000) and 2,000 nm (CPC 2000) were measured. Figure 14 As shown, the measured size of a particle with a diameter of 930 nm was 928.4 nm, implying a measurement error of 1.6 nm (=0.17%) and a coefficient of variation of 4.3. Furthermore, the measured size of a particle with a diameter of 2,000 nm was 1,999.7 nm, implying a measurement error of 0.3 nm (=0.01%) and a coefficient of variation of 1.8. Therefore, the particle size of the reference sample can be measured with extremely high accuracy.

[0076] Figure 15 Measurement results for a reference sample with virus size are shown. Figure 15 In this study, reference samples with particle sizes (i.e., diameters) of 100 nm, 153 nm, and 200 nm were measured. Figure 15 The measurement results shown also accurately measured the particle size of these reference samples.

[0077] Figure 16 A graph showing the measurement results for T4 bacteriophage and baculovirus is presented. Figure 16 As shown, the average particle size (average particle diameter) of T4 bacteriophage is 107.1 nm, and the average particle size of baculovirus is 171.4 nm. As demonstrated above, by using this disclosure, the particle size of T4 bacteriophage and baculovirus can be accurately measured.

[0078] Figure 17 A graph showing the measurement results of the influenza virus is displayed. (Example) Figure 17 As shown, the average particle size of the H1N1 influenza virus is 113.3 nm, and the average particle size of the H3N2 influenza virus is 112.4 nm. As demonstrated above, by using this disclosure, the particle size of influenza viruses can be accurately measured.

[0079] Figure 18 Charts showing the measurement results for various viruses are presented, particularly those for SARS-CoV-2, influenza A, influenza B, and bacteriophage T4. Figure 18 As shown, the particle size of these viruses can also be accurately measured.

[0080] Figure 19 The chart shows the measurement results for Pediococcus and Escherichia coli. (See attached image.) Figure 19 As shown, it can also accurately measure the particle size of Pediococcus and Escherichia coli.

[0081] Figure 20 A graph showing the measurement results for the measured sample (influenza virus) and a reference sample is displayed. That is, Figure 20 The measurement results are shown when a reference sample for calibration, in addition to the measurement sample, is dispersed in a solvent. For example... Figure 20 As shown, the average particle size of the reference sample is 150 nm. Furthermore, the average particle size of the measured sample (calibrated average particle size) is 99.7 nm. As demonstrated above, by using the reference sample for online calibration, the particle size of the sample (influenza virus) can be accurately measured.

[0082] Figure 21 A graph showing the measurement results of AC measurements performed when a DC (Direct Current) bias voltage is applied to particles with negatively charged surfaces is displayed. Figure 21 The peak widths are shown for AC measurements performed at 3 kHz when a DC bias voltage (in the x-axis direction) is applied to particles with a particle size of 250 nm (surface modified with "-COOH"). It is noteworthy that these peak widths are related to... Figure 7 The width W1 of waveform 33 of the combined impedance R shown in Figure 31 corresponds to this.

[0083] In many cases, biological nanoparticles (such as viruses and exosomes) are negatively charged. When the surface is negatively charged... Figure 21 When the bias voltage is increased towards the "negative" side (e.g., "-COOH"), the electrophoretic force increases more, and consequently the particle velocity increases more. As a result, the peak width decreases. In other words, as... Figure 21 As shown, the greater the reduction in bias voltage, the greater the reduction in peak width. Therefore, the ζ-potential can be determined by the peak width exhibited when a predetermined bias voltage is applied.

[0084] Figure 22 A graph showing the measurement results of the ζ-potential is presented. When using methods in related techniques, in some cases, the ζ-potential changes with a change in the applied voltage (bias voltage). Conversely, as... Figure 22As shown, when using the measurement method according to this disclosure, the value of the ζ-potential remains stable even when the applied voltage (bias voltage) is changed to 50mV, 100mV, and 150mV. Therefore, the ζ-potential can be accurately measured by using the method according to this disclosure.

[0085] In other words, the method in the related technology suffers from the following problem due to the use of DC measurement. Specifically, increasing the measurement voltage to improve measurement sensitivity also increases the driving voltage used for electrophoresis, thereby increasing the particle velocity and making measurement difficult. Conversely, when using AC measurement as described in this disclosure, the measurement of the ζ-potential and the measurement of electrophoresis can be controlled independently by using AC for measuring the ζ-potential and DC for electrophoresis. Therefore, by improving the measurement sensitivity of the ζ-potential while slowing down electrophoresis, the ζ-potential can be measured more accurately and stably.

[0086] Figure 23 and Figure 24 A graph showing the measurement results of the dielectric constant is presented. Figure 23 The measurement results of the Z' and Z" components of the impedance of samples A to D are shown. Figure 24 The upper part shows the display by Figure 23 The frequency-dependent graph of the impedance obtained from the measurement results is shown. Figure 24 The lower part shows the display by Figure 23 The graph shows the frequency correlation of the phase θ obtained from the measurement results.

[0087] Figure 23 and Figure 24 Sample A shown is a polystyrene particle with a diameter of 1.06 μm, and sample B is a polystyrene particle with a diameter of 0.99 μm and a surface modified with COOH. Further, sample C is a silica particle with a diameter of 0.96 μm, and sample D is a magnetic particle with a diameter of 1 μm and a surface modified with COOH. Figure 23 and Figure 24 The measurement results shown are as follows: the capacitance of sample A is 336 pF; the capacitance of sample B is 485 pF; the capacitance of sample C is 511 pF; and the capacitance of sample D is 444 pF.

[0088] It will be apparent from the disclosure described herein that embodiments thereof can be modified in many ways. These changes should not be considered a departure from the spirit and scope of this disclosure, and all such modifications, which are obvious to those skilled in the art, are intended to be included within the scope of the appended claims.

Claims

1. An object recognition method, the object recognition method comprising: The object dispersed in the solvent is fed into the microchannel; An AC voltage is applied to a measuring electrode located in the microchannel, and the AC characteristics of the object are measured as the object passes through the microchannel. as well as The combined impedance and phase are determined by using the measured AC characteristics, and the object is identified by using the determined combined impedance and phase. The parameters corresponding to the resistive component, zeta potential, and dielectric constant of the object are determined by using the combined impedance and phase, respectively. The object is identified by using the determined parameters corresponding to the resistance component, the ζ-potential, and the dielectric constant.

2. The object recognition method according to claim 1, wherein, The object is identified by mapping the parameters corresponding to the resistance component, the zeta potential, and the dielectric constant onto a three-dimensional coordinate system, wherein the axes of the three-dimensional coordinate system represent the resistance component, the zeta potential, and the dielectric constant, respectively.

3. The object recognition method according to claim 1, wherein, The parameter corresponding to the resistance component is a parameter corresponding to the size of the object. The parameter corresponding to the ζ-potential is a parameter corresponding to the surface potential of the object, and The parameter corresponding to the dielectric constant is a parameter corresponding to at least one of the structure and material of the object.

4. The object recognition method according to claim 1, wherein, Extract the in-phase component and the phase component, wherein the in-phase component is the component corresponding to the AC characteristic, and the phase component is the component offset from the in-phase component; The combined impedance and phase are determined by using the extracted in-phase component and the phase component; as well as The object is identified by using the time-varying changes in the combined impedance and the time-varying changes in the phase.

5. The object recognition method according to claim 4, wherein, The parameters corresponding to the resistive component and ζ-potential of the object are determined by using a waveform that indicates the time-varying nature of the combined impedance.

6. The object recognition method according to any one of claims 1 to 5, wherein The reference sample used for calibration is further dispersed in the solvent. The solvent in which the object and the reference sample are dispersed is supplied to the microchannel. The AC characteristics of the object are measured as the object passes through the microchannel. The AC characteristics of the reference sample were measured when the reference sample passed through the microchannel, and The object is identified based on the combined impedance and phase determined by using the AC characteristics of the object, and the combined impedance and phase determined by using the AC characteristics of the reference sample.

7. The object recognition method according to any one of claims 1 to 5, wherein, The frequency of the AC voltage applied to the measuring electrode is between 1 kHz and 100 MHz.

8. The object recognition method according to any one of claims 1 to 5, wherein, The solvent is an ionic liquid or an aqueous solution.

9. The object identification method according to any one of claims 1 to 5, wherein, The object is at least one organism selected from the group consisting of viruses, bacteria, and microorganisms.

10. The object recognition method according to any one of claims 1 to 5, wherein, The microchannel has a width that allows only one object to pass through at a time.

11. An object recognition device, the object recognition device comprising: Microchannels through which an object dispersed in a solvent flows; A measuring electrode is disposed at the microchannel; A measurement circuit configured to apply an AC voltage to the measurement electrodes and measure the AC characteristics of the object as the object passes through the microchannel; as well as An object identification unit is configured to determine a combined impedance and phase by using the measured AC characteristics, and to identify the object by using the determined combined impedance and phase. The object identification unit is further configured to determine parameters corresponding to the resistive component, ζ-potential, and dielectric constant of the object by using the combined impedance and phase, and to identify the object by using the determined parameters corresponding to the resistive component, the ζ-potential, and the dielectric constant.

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