Blood cell counting device and blood cell counting method

Abstract

A blood cell counting device 100 counts blood cells P dispersed in an electrolytic solution E using the Coulter counter method. The blood cell counting device 100 comprises a counting cell unit 101 and a signal extracting unit 105. The counting cell unit 101 outputs a sampling signal Sa for counting the blood cells P. The signal extracting unit 105 extracts the amplitude of the sampling signal Sa.

Description

Blood cell counting device, blood cell counting method Cross-reference to related applications

[0001] This application claims priority based on Japanese Patent Application No. 2024-227441 filed on December 24, 2024. The entire disclosure content of these is incorporated herein by reference and made part of the disclosure of this specification.

[0002] The present invention relates to a blood cell counting device and a blood cell counting method.

[0003] Conventionally, a device for measuring the number of blood cells using the Coulter counter method has been known. For example, in the blood cell measuring device described in U.S. Patent Publication No. 11808686, a pair of electrodes are arranged in a dispersion liquid of blood cells. One opening is arranged between both electrodes. The blood cell measuring device acquires a sampling signal indicating a change in impedance that occurs when blood cells pass through the opening, and the sampling signal is modulated with a sine wave. The blood cell measuring device counts the blood cells in the dispersion liquid by detecting the amplitude of the modulated sampling signal with a lock-in circuit.

[0004] However, the sine wave used for modulation requires high accuracy in its phase and amplitude, but it has been difficult to generate a sine wave without phase and amplitude deviations. Therefore, it has been difficult to improve the detection accuracy of the sampling signal.

[0005] In view of the above situation, an object of the present invention is to provide a blood cell counting device and a blood cell counting method that can improve the detection accuracy of the amplitude of a sampling signal with a simple configuration.

[0006] To achieve the above object, a blood cell counting device according to one aspect of the present invention counts blood cells dispersed in an electrolytic solution by the Coulter counter method. The blood cell counting device includes a counting cell unit and a signal extraction unit. The counting cell unit outputs a sampling signal for counting the blood cells. The signal extraction unit extracts the amplitude of the sampling signal.

[0007] Furthermore, in order to achieve the above objective, a blood cell counting method according to one aspect of the present invention counts blood cells contained in an electrolyte by the Coulter counter method. The blood cell counting method comprises the steps of outputting a sampling signal for counting the blood cells from a counting cell unit and extracting the amplitude of the sampling signal.

[0008] Further features and advantages of the present invention will be further revealed by the embodiments described below.

[0009] According to the present invention, it is possible to provide a blood cell counter and a blood cell counter method that can improve the detection accuracy of the amplitude of a sampling signal with a simple configuration.

[0010] A schematic diagram showing an example configuration of the blood cell counter according to this embodiment. A conceptual diagram showing the change in the amplitude of the extraction signal corresponding to the passage state of blood cells through the opening over time. A schematic diagram showing an example configuration of the blood cell counter according to the first modified embodiment. A schematic diagram showing an example configuration of the blood cell counter according to the second modified embodiment.

[0011] 100... Blood cell counter, 101... Counting cell unit, 102... Oscillator, 105... Signal extraction unit, 106... Calculation unit, 11... Container, 12... Aperture tube, 121... Hollow tube, 122... Partition, 123... Opening, 13... Pressure reducing device, 21... First electrode, 22... Second electrode, 23... Resistor, 24... Square wave power supply, 241... DC power supply, 242... Switch, 25... Voltmeter (signal generation unit), 41... Phase shift circuit, 42, 43, 44... ADC, 51... First multiplier, 52... Second multiplier, 6 1...First LPF, 62...Second LPF, 7...Signal synthesis unit, 81...Particle size calculation unit, 82...Counting unit, 83...Statistical unit, Sa...Sampling signal, Sd...Digital sampling signal, Sr...Reference signal, Sra...First phase shift signal, Srb...Second phase shift signal, Xa...First multiplication signal, X...In-phase signal, Ya...Second multiplication signal, Y...Orthogonal signal, So...Extraction signal, P...Blood cell, E...Electrolyte, F...Dispersion, It...Current, C1, C2, C3, C4, C5, C6, C7...Blood cell passage state

[0012] Embodiments of the present invention will be described below with reference to the drawings.

[0013] <1. Embodiment> The blood cell counter 100 counts blood cells P dispersed in an electrolyte E using the Coulter counter method. The electrolyte E is a liquid in which an ionic substance is dissolved in a solvent such as water, and may contain components other than ionic substances (such as surfactants). Hereinafter, the electrolyte E in which the blood cells P are dispersed will be referred to as the dispersion F. In the dispersion F, some blood cells P may be aggregated, as long as it does not hinder the counting of the blood cells P. In this embodiment, the blood cell counter 100 further measures the particle size of the blood cells P and calculates the particle size distribution of the blood cells P contained in the dispersion F. In this embodiment, the electrolyte E is physiological saline, and the blood cells P are, for example, white blood cells. However, the invention is not limited to this example, and the blood cells P may be other than white blood cells. For example, the blood cells P may be at least one of red blood cells, white blood cells, platelets, etc.

[0014] Figure 1 is a schematic diagram showing an example of the configuration of a blood cell counter according to this embodiment. As shown in Figure 1, the blood cell counter 100 comprises a counting cell unit 101, an oscillator 102, a signal extraction unit 105, and a calculation unit 106.

[0015] <1-1. Counting Cell Unit 101> The counting cell unit 101 generates a sampling signal Sa for calculating the number of blood cells P contained in the dispersion F, particle size, particle size distribution, etc., using a pore-type Coulter counter method, and outputs the sampling signal Sa to the signal extraction unit 105.

[0016] As shown in Figure 1, the counting cell unit 101 includes a container 11, an aperture tube 12, and a depressurizing device 13.

[0017] The container 11 is a bottomed cylindrical shape that extends vertically and stores the dispersion F.

[0018] The aperture tube 12 is cylindrical and extends vertically. The aperture tube 12 has a hollow tube 121, a partition wall 122, and one opening 123. The hollow tube 121 is a glass tube that extends vertically. The partition wall 122 is formed using a hard electrical insulating material such as a steel ball (for example, artificial ruby ​​or artificial sapphire) and is arranged integrally with the outer wall of the hollow tube 121. The opening 123 is a through hole located in the partition wall 122 and connects the inside and outside of the aperture tube 12. The lower part of the hollow tube 121, the partition wall 122, and the opening 123 are placed inside the container 11 and are immersed in the dispersion liquid F stored in the container 11. The lower end of the hollow tube 121 is closed off by a bottom cover (not shown), the bottom of the container 11, etc., to prevent the dispersion liquid F from entering.

[0019] The pressure reducing device 13 is positioned at the upper end of the hollow tube 121 and reduces the pressure inside the hollow tube 121. As a result, the dispersion F flows from inside the container 11 into the aperture tube 12 at a constant flow rate through the opening 123, in accordance with the pressure difference between the inside and outside of the aperture tube 12.

[0020] Furthermore, the counting cell unit 101 further includes a first electrode 21, a second electrode 22, a resistor 23, a rectangular wave power supply 24, and a voltmeter 25.

[0021] In this embodiment, the first electrode 21 is the cathode and is located inside the aperture tube 12 (hollow tube 121) and immersed in the dispersion F. In this embodiment, the second electrode 22 is the anode and is located inside the container 11, outside the aperture tube 12 (hollow tube 121), and immersed in the dispersion F. The first electrode 21 faces the second electrode 22 across the opening 123. In other words, the first electrode 21, the opening 123, and the second electrode 22 are aligned in one direction intersecting the vertical direction.

[0022] The resistor 23 and the square wave power supply 24 are connected in series between the first electrode 21 and the second electrode 22 outside the container 11. The first electrode 21, the resistor 23, the square wave power supply 24, the second electrode 22 (and the dispersion F between the first electrode 21 and the second electrode 22) form a continuous current circuit connected in series.

[0023] The square wave power supply 24 supplies a square wave current It to the current circuit. In this disclosure, "square wave" includes not only square waves without any "smoothness" in the rising and falling edges of each waveform, but also pseudo-square waves having a "smoothness" in at least one of the rising or falling edges of the waveform that does not depart from the spirit of the present invention.

[0024] For example, the square wave power supply 24 includes a DC power supply 241 and a switch 242. The DC power supply 241 supplies a DC current. The switch 242 opens and closes the electrical connection between the second electrode 22 and the DC power supply 241 in accordance with the sinusoidal reference signal Sr output from the oscillator 102, which will be described later, thereby switching the current flow in the above-mentioned current circuit from ON and OFF to the other. In this embodiment, the switch 242 switches the electrical connection and disconnection between the DC power supply 241 and the second electrode 22. For example, when the phase of the reference signal Sr is 0° or more and less than 180°, the switch 242 electrically connects the DC power supply 241 and the second electrode 22. As a result, the current flow in the above-mentioned current circuit is turned ON. Also, when the phase of the reference signal Sr is 180° or more and less than 360°, the switch 242 disconnects the electrical connection between the DC power supply 241 and the second electrode 22. As a result, the current in the aforementioned current circuit is turned OFF. Therefore, by switching the switch 242 ON / OFF, the square wave power supply 24 can supply the aforementioned current circuit with a square wave current It whose period and phase are synchronized with the reference signal Sr.

[0025] Preferably, the square wave current It is offset so that its current value is 0 or greater. More preferably, the low-level current value of the square wave current It is 0. This reduces the noise component of the current It due to environmental factors in the counting cell unit 101. However, this example does not exclude configurations in which at least a portion of the current value of It is less than 0.

[0026] The voltmeter 25 is connected in parallel with the resistor 23 and detects the voltage applied to the resistor 23. It outputs the voltage detected over time as a sampling signal Sa to the signal extraction unit 105. In other words, the voltmeter 25 is an example of the "signal generation unit" of the present invention and generates the sampling signal Sa based on the current It. The resistor 23 is a resistive element for sampling the sampling signal Sa. The sampling signal Sa is a rectangular wave signal whose period and phase are synchronized with the reference signal Sr. Preferably, the amplitude intensity of the sampling signal Sa is 0 or greater, and more preferably, the amplitude of the Low level of the rectangular wave sampling signal Sa is 0. However, this example does not exclude configurations in which the amplitude intensity of at least a portion of the sampling signal is less than 0.

[0027] <1-2. Oscillator 102> The oscillator 102 generates a sine wave of a predetermined frequency (for example, several MHz) as a reference signal Sr and outputs it to the counting cell unit 101 (its switch 242) and the phase shift circuit 41 of the signal extraction unit 105, which will be described later. In this embodiment, the phase and period of the reference signal Sr are synchronized with the clock signal output from an arithmetic unit such as a CPU. However, this example does not exclude configurations in which at least one of the phase or period of the reference signal Sr is not synchronized with the above-mentioned clock signal.

[0028] <1-5. Signal Extraction Unit 105> The signal extraction unit 105 is a so-called lock-in amplifier, and it extracts the amplitude and phase difference of the sampling signal Sa using the reference signal Sr output from the oscillator 102. The signal extraction unit 105 extracts only the signal component synchronized with the reference signal Sr from the sampling signal Sa as the extracted signal So, and outputs the extracted signal So to the calculation unit 106.

[0029] The signal extraction unit 105 includes a phase shift circuit 41, a first multiplier 51, a second multiplier 52, a first low-pass filter (LPF) 61, a second low-pass filter (LPF) 62, and a signal synthesis unit 7.

[0030] The phase shift circuit 41 can shift the phase of the reference signal Sr. For example, the phase shift circuit 41 outputs a first phase shift signal Sra, obtained by shifting the phase of the reference signal Sr output from the oscillator 102 by 0°, to the first multiplier 51, and a second phase shift signal Srb, obtained by shifting the phase of the reference signal Sr output from the oscillator 102 by (1 / 4) period (for example, +90° phase or -90° phase), to the second multiplier 52.

[0031] The first multiplier 51 multiplies the sampling signal Sa and the first phase shift signal Sra and outputs the first multiplied signal Xa to the first LPF 62. The first LPF 61 outputs a common-mode signal X, obtained by removing a predetermined high-frequency component from the first multiplied signal Xa, to the signal combining unit 7. The common-mode signal X is a signal that has the same phase component as the reference signal Sr in the first multiplied signal Xa.

[0032] The second multiplier 52 multiplies the sampling signal Sa and the second phase shift signal Srb and outputs the second multiplied signal Ya to the second LPF 62. The second LPF 62 outputs an orthogonal signal Y, obtained by removing a predetermined high-frequency component from the second multiplied signal Ya, to the signal synthesis unit 7. The orthogonal signal Y is a signal that has a component of the second multiplied signal Ya that is shifted by (1 / 4) period (for example, +90° phase or -90° phase) from the reference signal Sr.

[0033] The signal synthesis unit 7 calculates the amplitude and phase difference of the signal component synchronized with the reference signal Sr in the sampled signal Sa over time from the in-phase signal X and the orthogonal signal Y. For example, the signal synthesis unit 7 calculates twice the square root of the sum of the squares of the in-phase signal X and the squares of the orthogonal signal Y (i.e., [2 × √{X ２ +Y ２ The amplitude is calculated from the}]). The signal synthesis unit 7 also calculates the arctangent (i.e., tan) of the value obtained by dividing the orthogonal signal Y by the common-mode signal X (i.e., the quotient {Y / X}). －１ The phase difference with respect to the sampling signal Sa is calculated from {Y / X}. The signal synthesis unit 7 outputs the extracted signal So, which has the calculated amplitude and phase difference, to the calculation unit 106.

[0034] <1-6. Calculation Unit 106> The calculation unit 106 calculates the particle size and particle size distribution of blood cells P contained in the dispersion F based on the extraction signal So. The calculation unit 106 includes a particle size calculation unit 81, a counting unit 82, and a statistics unit 83. The particle size calculation unit 81 calculates the particle size of each blood cell P passing through the opening 123 based on the signal waveform of the extraction signal So in the time axis. The counting unit 82 measures the number of blood cells P passing through the opening 123 per unit time based on the signal waveform of the extraction signal So in the time axis. The statistics unit 83 calculates the particle size distribution of blood cells P based on the calculation results of the particle size calculation unit 81 and the counting unit 82. The calculation results are displayed on the display unit (not shown). The calculation results may also be stored in the storage unit (not shown).

[0035] Figure 2 is a conceptual diagram showing the change in the amplitude of the extraction signal So over time, corresponding to the state of blood cell P passing through the opening 123. In Figure 2, states C1, C2, C3, C4, C5, C6, and C7 indicate the state of blood cell P passing through the opening 123 at each point in time of the extraction signal So. State C1 shows the state before blood cell P flows into the opening 123. State C2 shows the state immediately before blood cell P in the container 11 flows into the opening 123. State C3 shows the state when blood cell P in the container 11 has begun to flow into the opening 123. State C4 shows the state when blood cell P is passing through the opening 123. State C5 shows the state when blood cell P has begun to flow out of the opening 123 into the aperture tube 12. State C6 shows the state immediately after blood cell P has flowed out of the opening 123 into the aperture tube 12. State C7 indicates that the blood cells P have finished flowing out of the opening 123 into the aperture tube 12.

[0036] In the counting cell unit 101, the magnitude of the electrical resistance between the first electrode 21 and the second electrode 22 changes depending on the electrical resistivity of the dispersion F flowing through the opening 123. For example, of the electrolyte E and blood cells P that make up the dispersion F, the electrical resistivity of blood cells P is greater than that of the electrolyte E. Therefore, the electrical resistivity of the dispersion F increases with increasing proportion of the volume of blood cells P relative to the volume of the opening 123 (i.e., the volume ratio occupied by blood cells P), and decreases with decreasing volume ratio of blood cells P.

[0037] For example, in states C1 and C7 where the dispersion liquid F flowing in the opening 123 is composed only of the electrolytic solution E, since the occupied volume ratio is 0%, the electrical resistivity of the dispersion liquid F in the opening 123 is low. Therefore, the amplitude of the extraction signal So is also small.

[0038] On the other hand, in states C2 to C6 where the dispersion liquid F flowing in the opening 123 contains blood cells P, the electrical resistivity of the dispersion liquid F in the opening 123 increases according to the above-described occupied volume ratio. Therefore, the amplitude of the extraction signal So also increases.

[0039] Specifically, in states C2 and C3 where blood cells P flow into the opening 123 (that is, the volume ratio of blood cells P increases), the electrical resistivity of the dispersion liquid F and the amplitude of the sampling signal Sa increase according to the increase in the occupied volume ratio of blood cells P. Therefore, the amplitude of the extraction signal So also increases.

[0040] In state C4 where the entire blood cells P pass through the opening 123, since the occupied volume ratio of blood cells P is constant, the electrical resistivity of the dispersion liquid F becomes constant, and the amplitude of the sampling signal Sa becomes a level corresponding to the electrical resistivity of the blood cells P. Therefore, the amplitude of the extraction signal So becomes flat. However, the change range of the electrical resistivity when the blood cells P pass through the opening 123 is small. Since the amplitude of the extraction signal So includes noise due to disturbance, it does not become a constant value.

[0041] In states C5 and C6 where blood cells P flow out from the opening 123 (that is, the volume ratio of blood cells P decreases), the electrical resistivity of the dispersion liquid F and the amplitude of the sampling signal Sa decrease according to the decrease in the occupied volume ratio of blood cells P. Therefore, the amplitude of the extraction signal So also decreases.

[0042] As described above, the amplitude of the extraction signal So becomes a level corresponding to the electrical resistivity of the blood cells P during the period when one blood cell P passes through the opening (that is, states C2 to C6 in Fig. 2). That is, during this period, the amplitude waveform of the extraction signal So forms one peak. On the other hand, the amplitude of the extraction signal So shows a low level during the period when there are no blood cells P in the opening (that is, states C1 and C7 in Fig. 2).

[0043] The particle size calculation unit 81 and the counting unit 82 calculate the number and particle size of the blood cells P based on the change in the amplitude of the extraction signal So as described above. That is, the particle size calculation unit 81 calculates the particle size (for example, the particle size based on volume) of the blood cells P passing through the opening 123 at each peak from the amplitude level of each peak of the extraction signal So in the state C4 (see FIG. 2). The counting unit 82 calculates the total number of blood cells P from the number of peaks of the extraction signal So per unit time. In addition, the counting unit 82 divides the amplitude levels of a plurality of peaks of the extraction signal So into ranges and calculates the number of blood cells P in different particle size ranges.

[0044] In addition, the particle size calculation unit 81 oversamples the amplitude of the extraction signal So in the state C4 (see FIG. 2) for each peak and calculates the particle size of the blood cell P from the average value. By oversampling the amplitude at each peak of the extraction signal So, the particle size calculation unit 81 can more accurately calculate the particle size of the blood cell P that passed through the opening 123 during the period of each peak.

[0045] Note that the above-mentioned oversampling refers to sampling the amplitude of the extraction signal So at a frequency exceeding the Nyquist frequency (half of the sampling frequency) of the sampling signal Sa. Note that the oversampling frequency is 1 [MHz] or more in the present embodiment. However, this example does not exclude a configuration in which the oversampling frequency is greater than the above-mentioned Nyquist frequency and less than 1 [MHz].

[0046] In addition, the method for calculating the above-mentioned average value is not particularly limited. For example, the above-mentioned average value is calculated by any calculation method such as arithmetic mean, geometric mean, harmonic mean, quadratic mean, etc. However, this example does not exclude a configuration in which a calculation method other than arithmetic mean, geometric mean, harmonic mean, and quadratic mean is adopted.

[0047] The oversampling frequency is more preferably 10 [MHz] or more (that is, several tens [MHz]), and even more preferably 100 [MHz] or more (that is, several hundreds [MHz]). By doing so, the particle size calculation unit 81 can calculate the particle size of the blood cell P more accurately.

[0048] For example, the volume-based particle size of blood cells P varies depending on their type. For instance, in the case of white blood cells, the average particle size increases in the order of lymphocytes, granulocytes, and monocytes. Furthermore, within granulocytes, the particle size increases in the order of halophils, neutrophils, and eosinophils. In other words, the average particle size is lymphocytes < granulocytes (halophils < neutrophils < eosinophils) < monocytes.

[0049] In this embodiment, by increasing the oversampling frequency to 10 MHz or higher (or 100 MHz or higher), the statistics unit 83 counts white blood cells by type based on the calculation results of the particle size calculation unit 81 and the counting unit 82. These calculation results are displayed on the display unit or stored in the memory unit.

[0050] In the above embodiment, the signal extraction unit 105 is an analog circuit and outputs an analog extracted signal So. However, the system is not limited to this example, and at least a part of the signal extraction unit 105 may be a digital circuit. The signal extraction unit 105 may also output a digital extracted signal So.

[0051] <1-2. First Modification of the Embodiment> Figure 3 is a schematic diagram showing an example of the configuration of a blood cell counter 100 according to the first modification of the embodiment. In the first modification, a configuration different from the embodiment described above will be explained. Also, the same reference numerals are used for components similar to those in the embodiment, and their descriptions may be omitted.

[0052] In the first modified example, the extracted signal So is generated using the digitized sampling signal Sa. The signal extraction unit 105 of the first modified example further includes an ADC (analog-to-digital converter) 42. The ADC 42 converts the sampling signal Sa output from the voltmeter 25 from an analog signal to a digital signal and outputs the digital sampling signal Sd to the first multiplier 51 and the second multiplier 52. Even in this way, the blood cell counter 100 can improve the detection accuracy of the amplitude of the sampling signal Sa with a simple configuration.

[0053] <1-3. Second Modification of the Embodiment> Figure 4 is a schematic diagram showing an example of the configuration of a blood cell counter 100 according to the second modification of the embodiment. In the second modification, a configuration different from the above-described embodiment and the first modification will be described. Also, the same reference numerals are used for components that are the same as in the embodiment and the first modification, and their descriptions may be omitted.

[0054] In the second modified example, the signal extraction unit 105 converts the common-mode signal X and the quadrature signal Y into digital signals. The signal extraction unit 105 of the second modified example further includes a phase shift circuit 41, a first multiplier 51, a second multiplier 52, a first LPF 61, and a second LPF 62, as well as ADCs (analog-to-digital converters) 42 and 43. The ADC 43 converts the common-mode signal X output from the first LPF 61 from an analog signal to a digital signal and outputs the digital common-mode signal Xd to the calculation unit 106. The ADC 44 converts the quadrature signal Y output from the second LPF 62 from an analog signal to a digital signal and outputs the digital quadrature signal Yd to the calculation unit 106.

[0055] The calculation unit 106 first performs calculations similar to those of the signal synthesis unit 7 in the embodiment and its first modified example. For example, the calculation unit 106 calculates the amplitude and phase difference of the digital signal components over time from the digital common-mode signal Xd and the quadrature signal Yd. The digital signal components correspond to the signal components synchronized with the reference signal Sr in the sampling signal Sa.

[0056] Even in this way, the blood cell counter 100 can improve the detection accuracy of the amplitude of the sampling signal Sa with a simple configuration.

[0057] <2. Remarks> Embodiments of the present invention have been described above. The above embodiments are illustrative, and various modifications are possible in the combination of each component and each process, and it will be understood by those skilled in the art that these modifications fall within the scope of the present invention.

[0058] <3. Summary> Below, we will provide a summary of the embodiments described so far.

[0059] For example, the blood cell counter 100 disclosed herein is a blood cell counter 100 that counts blood cells P contained in an electrolyte E by the Coulter counter method, and comprises a counting cell unit 101 that outputs a sampling signal Sa for counting the blood cells P, and a signal extraction unit 105 that extracts the amplitude of the sampling signal Sa (first configuration).

[0060] The blood cell counter 100 in the first configuration described above is a blood cell counter 100 that counts white blood cells contained in the electrolyte E by the Coulter counter method, and further comprises a calculation unit 106 that calculates the particle size and particle size distribution of white blood cells based on the extraction signal So output from the signal extraction unit 105, and the calculation unit 106 may be configured to count white blood cells dispersed in the electrolyte E by type (second configuration).

[0061] Furthermore, the blood cell counter 100 of the first or second configuration described above may further include an oscillator 102 that outputs a sinusoidal reference signal Sr to the counting cell unit 101, and the counting cell unit 101 may have a configuration (third configuration) comprising: a DC power supply 241 that outputs a DC current (current It); a switch 242 that turns the supply of the DC current (current It) ON / OFF according to the amplitude of the reference signal Sr; and a signal generation unit 25 that generates the sampling signal Sa based on the DC current (current It).

[0062] Furthermore, the blood cell counter 100 in the third configuration described above may also be configured such that the oscillator 102 further outputs the sinusoidal reference signal Sr to the signal extraction unit 105, and the signal extraction unit 105 extracts the amplitude of the sampling signal Sa using the reference signal Sr (fourth configuration).

[0063] Furthermore, the blood cell counter 100 having any of the first to fourth configurations described above may also have a configuration in which the current value of the DC current (current It) is 0 or greater (fifth configuration).

[0064] Furthermore, the blood cell counter 100 according to any of the first to fifth configurations described above may also have a configuration in which the current value at the Low level of the DC current (current It) is 0 (sixth configuration).

[0065] Furthermore, the blood cell counting method disclosed herein is a blood cell counting method for counting blood cells P contained in an electrolyte solution E by the Coulter counter method, and comprises the steps of: outputting a sampling signal Sa for counting the blood cells P from a counting cell unit 101; and extracting the amplitude of the sampling signal Sa (seventh configuration).

Claims

1. A blood cell counter for counting blood cells contained in an electrolyte solution using the Coulter counter method, comprising: a counting cell unit that outputs a sampling signal for counting the blood cells; and a signal extraction unit that extracts the amplitude of the sampling signal.

2. A blood cell counter for counting leukocytes dispersed in an electrolyte by the Coulter counter method, further comprising a calculation unit that calculates the particle size and particle size distribution of leukocytes based on an extraction signal output from the signal extraction unit, wherein the calculation unit counts the leukocytes dispersed in the electrolyte by type, as described in claim 1.

3. The blood cell counter according to claim 1 or claim 2, further comprising an oscillator that outputs a sinusoidal reference signal to the counting cell unit, wherein the counting cell unit comprises a DC power supply that outputs a DC current, a switch that turns the supply of the DC current ON / OFF according to the amplitude of the reference signal, and a signal generation unit that generates the sampling signal based on the DC current.

4. The hemocytometer according to claim 3, wherein the oscillator further outputs the sinusoidal reference signal to the signal extraction unit, and the signal extraction unit extracts the amplitude of the sampling signal using the reference signal.

5. The blood cell counter according to any one of claims 1 to 4, wherein the current value of the DC current is 0 or greater.

6. The blood cell counter according to any one of claims 1 to 5, wherein the current value at the Low level of the DC current is 0.

7. A blood cell counting method for counting blood cells contained in an electrolyte solution using the Coulter counter method, comprising the steps of: outputting a sampling signal for counting the blood cells from a counting cell unit; and extracting the amplitude of the sampling signal.

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