JPH0737934B2 - Return signal removal device for particle analyzer - Google Patents

Description

TECHNICAL FIELD The present invention relates to a return signal removing device for a particle analyzer.

(Prior Art) Among the particle detection devices, the conductive type is one in which a pair of electrodes is immersed in a suspension of measurement particles suspended in an electrolyte solution,
As shown in FIG. 32, the electrodes are isolated from each other by an insulating wall 101 having minute pores 100, and a potential difference is applied between the electrodes to form pores 1.
It is configured such that a current flows between the electrodes only through 00. In this particle detection device, when a water pressure difference is applied between the liquids on both sides to allow the particles to flow through the pores 100 together with the suspension, the particles can be passed through by appropriately selecting the diameter of the pores 100 with respect to the particle diameter. A current change proportional to the particle volume is generated between the electrodes.

The waveform of the particle detection signal at this time is the pore 10 shown in FIG.
For example, the passage of the particles 102 at 0 is as shown in FIG. However, in the figure, the passage of particles is shown in an overlapping manner, and in practice, the particle concentration of the suspension is adjusted so that each state occurs separately.

In FIG. 33, the waveform a'is the case of the passage route a in which the particles 102 pass very close to the wall surface of the pore 100, and the pore 1
There are sharp peaks at the 00 entrance and exit, with a gentle valley between the two peaks. That is, the signal of this waveform a'is a valley waveform signal.

The corrugation b'is the case of the passage route b in which the two particles 102 closely pass near the center of the pore 100, and there is a deep valley between the two peaks.

Waveform C'is the case of the passage C in which the particles 102 pass exactly through the center of the pore 100, and shows a symmetrical and clean waveform with one peak. The signal of this waveform C'is hereinafter referred to as a single peak waveform signal.

Waveform D ′ is a case of a passage D that obliquely passes near the wall surface of the pore 100 at the entrance and near the center at the exit, and shows a sharp peak only near the entrance.

The reason why the particle 102 shows a sharp peak when the particles 102 pass near the wall surfaces of the inlet and outlet of the pore 100 is that the current density in this vicinity (so-called edge portion of the pore 100) is high. Further, the width of the corrugation is longer when the particles 102 pass near the wall surface of the pore 100 than when they pass through the center of the pore 100, because the flow velocity is slow near the wall surface and passes through the center portion. This is because it takes longer time for the particles 102 to pass than when the above.

From the above, even if the particles 102 having the same size pass through the pores 100, the peak value of the peak of the waveform will be different due to the difference in the passage route. Therefore, in a strict sense, a detection signal having a size proportional to the volume of the particle cannot be obtained, and the particle size distribution drawn from the peak value of this peak contains an error. Therefore, the particle analyzer generally has a means for removing the error so that the particle size can be accurately detected.

However, the particles that have passed through the pores 100 will be
Even when the flow returns as shown by reference numerals 105 and 106 in the figure, a current smaller than the current accompanying the passage of particles flows between the electrodes, so that an erroneous detection signal with a gentle waveform as shown in Fig. 35 (a) is generated. It will occur further. Curve 105a is a sign
The flow corresponds to the flow of 105, and the curve 106a corresponds to the flow of reference numeral 106. Hereinafter, these signals are referred to as return signals.

Conventionally, the following measures have been taken to detect such a return signal.

The first means is the so-called "sheath flow" in which the flow path that passes through the pores of the particles is hydrodynamically narrowed to a narrow range in the center.
Is formed. By this means the particle suspension is
In principle, no return signal is generated because the particles that have passed through the narrow range of the center of 100 are passed through by hydrodynamics and the particles that have once passed do not return to the vicinity of the pores again. However, the device is expensive because it requires a complicated fluid mechanism.

On the other hand, the second means is to discriminate the waveform due to passage of particles and the return waveform according to the time width of the signal, for example, Kachel, V (1982) Sizing of Cells by th.
e Elecrical Resistance Pulse Tecnique, in: Cell Anal
ysis Vol.1 (N.Catsimpoolas, ed.), Plenum Press, New
I am touching York, pp.195-331.

That is, more specifically, in the case of the return signal 105a shown in FIG. 35 (a), the particle detection signal is differentiated into a low frequency component as shown in FIG.
The pulse width Tw is defined as the time for which the voltage crosses the reference voltage Vref, and the pulse width is compared with a predetermined filter pulse Tf. When Tw <Tf, it is determined to be platelets, and when they are opposite, it is determined to be a return signal.

(Problems to be Solved by the Invention) In the second means, the waveform of the dance return signal has various levels, and in the case of the dance return signal 106a, the reproduction signal of the differential thereof.
The pulse width Tw ′ when 106b crosses the reference voltage Vref is Tw ′.
Since it is <Tf, it is determined to be platelets. That is, according to the second means, as shown in FIG. 36, since the pulse width Tw when the blood cell particles are the waveform of the direct current reproduction of the differential signal of the platelets is small, the return signal with a long pulse width Tw is discriminated from the platelets. However, the narrow return signal cannot be distinguished from platelets.

Further, as shown in FIG. 37, when the blood cell particles are red blood cells and when the red blood cells are reflected back immediately after passage of the red blood cells, the signal of the red blood cell as shown in FIG. 38 (a) Is saturated) and the return signal is continuous. That is, S1, S1 '~ S4, S4' at the same point in time when the flow process of red blood cells and the process of the flow-back signal in Fig. 37 are the same.
This is because the signals overlap with each other as shown in FIG. When this signal is differentiated and DC reproduced, it becomes as shown in FIG. That is, the reference voltage divides the waveform into a red blood cell signal and a return signal. However,
The pulse width Tw across the reference voltage of the return waveform becomes shorter,
Therefore, it has a drawback that it is erroneously discriminated as platelets.

As a result, when each of the above cases occurs frequently, the particle size distribution becomes as shown in FIG. That is, if the solid line is the true particle size distribution, the particle size distribution is like the dotted line. In the case of platelets, the broken line shows a rise on the left side of the solid line, which is due to erroneous discrimination in FIG. 35, and the broken line at the boundary between platelets and red blood cells is due to erroneous discrimination in FIG.

Therefore, an object of the present invention is to provide a return signal removing device for a particle analyzer that can remove the return signal more reliably.

(Means for Solving the Problem) The return signal removing device of the particle analyzer of the present invention is a detecting device for outputting a particle detecting signal generated as particles pass through the pores, and the particle detecting signal. Differential signal generating means for differentiating and outputting a differential signal, and comparing the particle detection signal and the differential signal, the particle detection signal is determined as a return signal when the differential signal is smaller than the particle detection signal And a return signal for processing the particle detection signal and removing the particle detection signal to be the return signal by the signal determined to be the return signal of the return signal determination means. And a processing unit having a signal removing unit.

(Operation) According to the configuration of the present invention, when the particle detection signal output from the detection means is due to the passage of particles through the pores, the signal rises sharply, so the differential signal of the particle detection signal is more than the particle detection signal. However, the differential signal of the Mai-return signal does not become larger than the Mai-return signal because the Mai-return signal rises slowly. Therefore, the dance return signal determining unit compares the particle detection signal and its differential signal to determine the dance return signal, and the dance return signal removing unit removes the dance return signal from the processing target of the processing unit. The return signal can be removed more reliably.

(Embodiment) An embodiment of the present invention will be described with reference to FIGS. 1 to 31. That is, in FIG. 1, the return signal removing device of this particle analysis device differentiates the particle detection signal from the detection means 1 that outputs a particle detection signal generated as particles pass through the pores. A differential signal generating means 2 for outputting a differential signal is compared with the particle detection signal and the differential signal, and a signal for judging the particle detection signal as a return signal when the differential signal is smaller than the particle detection signal. A dance return signal determining means 3 for outputting and a dance return signal for processing the particle detection signal and for removing the particle detection signal to be the dance return signal by the signal determined to be the dance return signal of the dance return signal determining means 3. And a processing means 4 having a removing means.

Therefore, as shown in FIG. 1, the detection means 1 outputs the particle detection signal M1, the differential signal generation means 2 outputs the differential signal M2 of the particle detection signal M1, and the return signal determination means 3
The particle detection signal M1 and the differential signal M2 are compared with each other to output a signal e which is judged to be a return signal when the differential signal M2 is small, and the return signal removing means detects the return signal in the particle detection signal M1. The particle detection signal can be removed from the processing target of the processing means 4.

Therefore, according to this embodiment, when the particle detection signal output by the detection means 1 is due to the passage of particles through the pores, the signal rises sharply, so the differential signal of the particle detection signal is more than the particle detection signal. However, the differential signal of the Mai-return signal is not larger than the Mai-return signal because the Mai-return signal rises slowly. Therefore, the dance return signal determining means 3 compares the particle detection signal and its differential signal to determine the dance return signal, and the dance return signal removing means removes the dance return signal from the processing target of the processing means 4. ,
The return signal can be removed more reliably.

The entire particle analyzer to which the return signal removing device of this embodiment is applied will be described below. In FIG. 2, 11 is a container
A detector (insulating wall) constituting the detection means 1 in which 13 particles are immersed in a suspended liquid 12 has pores 14 near the lower end thereof. The pores 14 are located below the liquid surface of the liquid 12,
Electrodes 15 and 16 are arranged inside and outside thereof, respectively. A liquid control device 17 is for sucking the liquid 12 through the pores 14 in the detector 11.

A detection circuit 18 generates a pulse-like signal proportional to the size of the particle each time the particle passes through the pore 12 based on the difference in electrical impedance between the particle and the liquid 12.

Reference numeral 9 denotes a waveform processing device for waveform-processing the particle detection signal detected by the detecting means 1, and the differential signal generating means 2 of the present invention,
It includes a return signal determining means 3 and a processing means 4.

Reference numeral 10 denotes an arithmetic processing unit, which analyzes a signal sent from the waveform processing unit 9 and showing a crest value proportional to the volume of particles, and performs various arithmetic processes such as drawing a particle size distribution chart and counting the number of particles. Is.

Next, the waveform processing device 9 will be described. As shown in FIG. 3, the waveform processing apparatus 9 includes a pre-processing block C including the differential signal generating means 2 of FIG. 1 and a control including the dance return signal determining means 3 and the dance return signal removing means of FIG. It is composed of a block B and a bottom output block A including processing means excluding the return signal removing means of FIG. The pre-processing block C has a DC reproducing function of clamping the DC level of the particle detection signal sent from the detection circuit 18 to a predetermined level and a function of differentiating the particle detection signal. Among the signals output from the preprocessing block C, the DC reproduction signal of the particle detection signal is sent to the bottom output block A and the control block B, and the differential signal is sent to the control block B. The control block B receives the DC reproduction signal and the differential signal,
A control signal for controlling the bottom output block A is output.
The bottom output block A receives the DC reproduction signal from the pre-processing block C and the control signal from the control block B as inputs,
It has a function of outputting the peak value of the valley when the DC reproduction signal is a valley waveform signal.

First, the processing block C will be described in detail. FIG. 4 is a circuit diagram showing an embodiment of the preprocessing block C. The pre-processing block C is mainly the first DC regeneration block K.
1, first differential block DIF1, second DC regeneration block K2, second differential block constituting differential signal generating means 2 of the present invention
A particle detection signal (single peak waveform signal in the figure) of the detection means 1 is input to each of them via an operational amplifier OP1 of a voltage follower, which is composed of DIF2. The pre-processing block C includes a reference signal generation block REF, and the reference signal Ref1,
Although Ref2 is generated, the reference signal generation block REF may be arranged in the control block B.

The first DC recovery block K1 sets the DC level of the particle detection signal to a predetermined level, and the operational amplifier OP2,
It is composed of OP3, resistors R1 and R2, capacitor C1, and diodes D1 and D2. The crest value of the direct current reproduction signal DC1 in which the particle detection signal is direct current reproduced in the first direct current reproduction block K1 is detected by the waveform processing device 9, and the arithmetic processing device 10 shown in FIG.
Parsed in. In addition, the DC reproduction signal DC1 is supplied to the operational amplifier OP4.
The inverted signal {circle around (1)} is compared with the differential signal V1 in the control block B, which will be described later, and is applied to detect particles that have passed through the pores 14. R3 and R4 are resistors.

The first differentiation block DIF1 is for differentiating the particle detection signal, and includes operational amplifiers OP5, OP6, resistors R5 to R8, a capacitor C2,
Composed of C3.

The differential signal V1 differentiated by the first differential block DIF1 is
By comparing with the first reference signal Ref1 in the control block B which will be described later, the return signal and noise with a low crest value are removed, and the peak and valley positions of the particle detection signal are detected by comparing with the zero potential. can do. That is, the return signal is obtained when the particles 20 and 21 have returned to the vicinity of the pores 14 as shown by the broken line in FIG. In the case of the particle 21, the return signal having the waveform as shown in FIG. 6A and in the case of the particle 20 the signal having the waveform as shown in FIG. 6B is generated in the detection means 1. . Since the magnitude of such a return signal is much smaller than the magnitude of the true particle detection signal generated when the particles pass through the pores 14,
When measuring only particles of similar size, the return signal can be discriminated based on the signal size, so there is no effect on particle measurement. However, when the large particles and the small particles are mixed in the suspension, the non-return signal of the large particles becomes almost equal to the detection signal of the small particles. Therefore, the detection signal of a small particle and the return signal of a large particle cannot be discriminated from each other depending on the size of the signal, which adversely affects the measurement of a small particle.

That is, when the return signals of FIGS. 6 (a) and 6 (b) are differentiated, a waveform as shown in FIG. 6 (c) is obtained with respect to FIG. 6 (a), and a waveform as shown in FIG. The waveform is as shown in d). Then, by comparing with the reference signal Ref1, the return signal having a low peak value in FIG. 9A can be removed. However, it is not possible to remove the sowing return signal of FIG. 6B, which has a high peak value.

Further, since the first differential block DIF1 is provided with the integral characteristic in the high frequency region, in the case of a signal including noise as shown in FIG. 7 (a), the differential signal V1 becomes the signal shown in FIG. 7 (b). , By comparing with the reference signal Ref1, noise can be removed.

Further, as shown in FIG. 8 (a), points P1 to P3, B1 at which the differential signal V1 in FIG. 8 (b) obtained by differentiating the particle detection signals of the single peak waveform signal and the valley waveform signal have zero potential are Since it corresponds to the peak P or the valley B of the original signal, it is possible to detect the position of the peak and the valley of the particle detection signal by comparing the differential waveform with the zero potential and detecting the position where the differential waveform crosses zero. You can

The second direct current regeneration block K2 outputs the direct current regeneration signal DC2 for direct current regeneration of the particle detection signal and removal of the return signal having a high peak value, and the operational amplifiers OP8, OP9 and the resistor R
It consists of 8, R9, capacitor C4, and diodes D3, D4. First DC regeneration block K1 and second DC regeneration block K2
Generally have different cutoff frequencies, and the circuit constants are set so as to have the optimum characteristics according to the purpose.

The second differential block DIF2 differentiates the particle detection signal and outputs the differential signal V2 (corresponding to the symbol M2 in FIG. 1) of the present invention for comparison with the DC reproduction signal DC2. The operational amplifier OP10, It is composed of OP11, resistors R10 to R13, and capacitors C5 and C6. First derivative block DIF1 and second derivative block
DIF2 also generally has different differential characteristics.

By comparing the DC reproduction signal DC2 and the differential signal V2, the return signal which could not be removed in the processing of the differential signal V1 in FIG. 6 because the peak value is high can be removed.
That is, as shown in FIG. 9 (a), in the case of a normal particle detection signal generated by the passage of particles through the pores 14, the differential signal V2 is higher than the DC reproduction signal DC2 (V2> DC2), so the differential signal V2 crosses the DC playback signal DC2, but in the case of a return signal, the differential signal V2 becomes lower than the DC playback signal DC2 (V2 <DC2) as shown in Fig. 7B, so the differential signal V2 is DC. Never cross the playback signal DC2. In this way, it becomes possible to discriminate between the particle detection signal and the return signal. In addition, red blood cells were reflected back immediately after passing through the pores (similar to Fig. 37), and the particle detection signal was differentiated even if the return signal continued as shown in Fig. 17. The differential signal V2 does not cross the return signal.

When the measurement particles are blood cells, and when measuring platelets in the blood cells, this return signal removal function is essential. This is because blood contains red blood cells and white blood cells in addition to platelets unless special treatment is applied. That is, these red blood cells and white blood cells are much larger than platelets, and the peak value of the return signal generated when red blood cells and white blood cells fly back is the wave of the particle detection signal generated when platelets pass through the pores. This is because it is almost equal to the high price. Therefore, the second DC regeneration block DC2 and the second differential block DIF2 are indispensable for platelet measurement.

The reference signal generation block REF is an operational amplifier OP7, R17 to R21,
It is composed of a capacitor C8 and a Zener diode ZD.

Next, the control block B will be described in detail. Figure 3 is the third
FIG. 11 is a block configuration diagram in which the control block B in the figure is further divided into smaller blocks, and FIG. 11 is a circuit diagram thereof. Of the signals input to the control block B, the signals V1, V2, DC1, ▲ ▼, DC2, Ref1, Ref2 excluding the count start signal are all sent from the pre-processing block C shown in FIG. is there. In each block shown in Fig. 11, COM1
COM4 is a comparator, DQ1 to DQ5 is a D latch, I1 to I13 are inverters, NAND is a NAND circuit, NO is a normally open analog switch, and V1 and V2 are multivibrators.

In this example, a case where large particles and small particles are mixed in the suspension, for example, red blood cells, white blood cells and platelets are mixed, and only small platelets are measured from the mixed particles will be described.

Peak / valley detection block L1 shown in FIGS. 10 and 11.
Is the differential signal V1 and the reference signal Ref1 by the comparator COM1.
In comparison with FIG. 6 and FIG. 7, the return signal and noise having a low peak value are removed, and the differential signal V1 is compared with the zero potential to compare the peak and valley of the DC reproduction signal DC1. The signal a for detecting the position of is output. That is, when the differentiated signal V1 is smaller than the reference signal Ref1, the signal a is at a low level (hereinafter "L") as shown in FIG. 12 (b).
Is written. ), On the contrary, when it becomes large, it becomes a high level (hereinafter referred to as “H”), and the signal a does not respond to a return signal or noise having a low peak value. Differential signal V1 is reference signal Ref1
When it is larger than that, if the b input from the input inhibition block L6 to the center pulse generation block L5 is H, the Q output c of the D latch DQ1 becomes H as shown in FIG. 12 (d). At this time, at the same time, the analog switch NO of the peak / valley detection block L1 is closed by the output of the D latch DQ1 of the center pulse generation block L5, and the reference signal Ref1 falls to zero potential as shown in 12th (a). Therefore, this time, the differential signal V1 and the zero potential are compared by the comparator COM1, so that the signal a becomes a signal for detecting the positions of the peak P and the valley B as described in FIG.

The passage detection block L2 has the direct current reproduction signal DC1 as described above.
The passage of particles is detected by comparing the inversion signal (1) obtained by inverting and the differential signal V1 in the comparator COM2. That is, when the differentiated signal V1 becomes smaller than the inverted signal ∇, the output d becomes H and the T input of the D latch DQ1 of the center pulse generation block L5 becomes L, so the Q output c becomes L. As shown in FIG. 12, when the Q output c becomes L, the peak of the particle detection signal has already passed, so the Q output c and the output d are signals corresponding to the passage of one particle. Further, since the output becomes H, the analog switch NO is opened and the reference signal Ref1 is input to the comparator COM of the peak / valley detection block L1 (Fig. 12 (a)).

FIG. 12 shows the case of a valley waveform signal, FIG. 13 shows the case of a single peak waveform signal, and FIG. 14 shows the case of two consecutive single peak waveform signals.

Thus, since the passage detection block L2 is a method of detecting passage of particles by comparing the differential signal V1 and the inverted signal ▲ ▼, in the case of the valley waveform of FIG. 12 and the single peak waveform of FIG. 13, There is only one pulse in the signals c and d, and it is judged that one particle has passed, and in the case of the waveform when two particles pass closely as shown in Fig. 14, the signals c and d have It can be judged that two pulses occur and two particles pass. Also, since both the differential signal V1 and the inverted signal V change depending on the size of the particle detection signal, the time position of passage detection of the particle detection signal is substantially constant regardless of the size of the particle.

In addition, the resistor R22 (3.3K
Ω) is connected, but this 6th pin is called a strobe terminal, and the output becomes H regardless of the input while drawing a current of 3 to 5 mA. As a result, the movement of the comparator is stopped and the generation of noise is prevented when it is not necessary.

The return-removal block L3 corresponds to the return-return determination means 3 in FIG. 1, and as described above, the differential signal V2 of the particle detection signal and the DC reproduction signal DC2 are compared in the comparator COM3, and the peak value is high. Although it does not respond to the return signal, it outputs an output e that responds to the reproduction signal DC2 of the particle detection signal such as platelets. That is, as shown in FIG. 15, when a particle such as platelet N1 or red blood cell N2 passes, the DC reproduction signal DC2 of the particle detection signal is crossed with the differential signal V2, so that the output e (FIG. 15) is generated. (C)) is H
become. In the case of the return signal N, the differential signal V2 does not cross the DC reproduction signal DC2, so the comparator COM
3 is not inverted and the output e of the block without return is still L.

The large signal elimination block L4 includes a DC reproduction signal DC1 and a reference signal R
Comparing ef2 with the comparator COM4, it is determined that the signal exceeding the reference signal Ref2, which is the large signal discrimination level, is a signal due to large particles such as red blood cells and white blood cells.
When the DC reproduction signal DC1 exceeds the reference signal Ref2, the output f of the comparator COM4 becomes L as shown in FIG. 15 (d).

The peak hold control block L7 is the processing means 4 of FIG.
It also serves as a return signal removing means included in the above, and outputs a control signal ▲ ▼ / T that enables peak hold. While the Q output c indicating the passage of one particle in the center pulse generation block L5 is H,
Comparator COM3 of is inverted and T input e of D latch DQ2
When rises, the D input c of the D latch DQ2 appears at the Q output g and the Q output g becomes H (Fig. 15 (e)).
While the output g is H, the peak hold described later is possible. D latch DQ2 is the reset pulse generation block L11 Q
Although it is reset by the output, it is also reset when the output f of the large signal elimination block L4 becomes L upon detection of the large signal (FIG. 15 (e)). Therefore, in the case of a large signal, the g signal once becomes H but is not held until the particle passage detection time and becomes L, so that the peak value of the large signal is not output as described later. The Q output g of the D latch DQ2 of the peak hold control block L7 is the inverter I9.
The control signal ▲ ▼ / T is output via (Fig. 16 (o)) and sent to the bottom output block A in Fig. 3,
It controls the normally closed analog switches NC1 and NC2 shown in FIG.

Incidentally, the D latch DQ2 of the peak hold control block L7
Needs to set the timing as follows. That is, when the D input that receives the Q output c of the latch DQ1 is H and the T input that receives the output e of the block L3 rises, the Q output g becomes H, but after the output e rises first, Even when the Q output c becomes H, g remains L, so that the differential signal V1, the reference signal Ref1, and the differential signal V2 are set so that the Q output c rises before the output e.
And the frequency characteristic of the DC reproduction signal DC2 and the signal size need to be set.

The peak control block L9 outputs a control signal PC that holds the first peak of the DC reproduction signal DC1.
Peak hold control block L7 Q output g of D latch DQ3 D input is H when peak / valley detection block L
Receiving the inverted signal of the signal a which detected the position of the peak / valley of 1 When the T input rises, the output is L and the control signal PC
Becomes H (FIGS. 16 (h) to (j)). The control signal PC controls the normally open type analog switch NO1 shown in FIG. 19 of the bottom output block A, and holds the first peak when the control signal PC is H.

The valley control block L8 holds the valley of the DC reproduction signal DC1 and outputs control signals BC1, ▲ ▼ for distinguishing the valley waveform signal from the single peak waveform signal, and the Q output of the peak hold control block L7. When the D input of the D latch DQ4 receiving g is H and the T input receiving the signal a'inverted twice from the signal a rises, the Q output becomes H.
Then, the Q output becomes L. Control signal by H of Q output ▲
▼ becomes L, and control signal BC1 becomes H by L of Q output.
(Fig. 16 (h), (k) to (m)). The falling edge of the control signal {circle around ()} is slightly delayed from the rising edge of the control signal BC1 by a delay circuit composed of a resistor R23 and a capacitor C9 to prevent floating as described later. Both the control signals BC1 and ▲ ▼ are sent to the bottom output block A, the control signal BC1 controls the normally open type analog switches NO2 and NO3, and the control signal ▲ ▼ controls the normally closed type analog switch NC3.

The output control block L10 outputs the control signal ▲ ▼ for controlling the output signal of the bottom control block A, and when the B input of the monostable multivibrator V1 receiving the Q output g of the peak hold control block L7 is H. Center pulse generation block that detects the passage of a single particle
When the A input that receives the Q output c of L5 falls, a pulse having a time width of ts is output from the Q output, and the control signal ▲ ▼ in FIG. 16 (n) is output. This output ▲
▼ is also sent to the bottom output block A, and controls the normally closed analog switch NC4 shown in FIG.
During the ts time of the signal, the output signal indicating the peak value is output in pulses from the bottom output block A.

In the input inhibition block L6, the Q output b is L because the D latch DQ5 is set by the output of the output control block L10.
Therefore, the a input to the center pulse generation block L5 is prohibited, and the peak value output is prevented from being erroneously operated by the near passage pulse when the particles continuously pass through the pores. If the output b of the D latch DQ5 of the input prohibition block L6 is L, this circuit will not operate, so it must be set to H before the counting is started. In this case, the D input of the D latch DQ5 is input. Pull down
If the T input is connected to a counting start signal (rising signal) from the outside, the signal b always becomes H at the start of counting, and the state where no inhibition is applied can be achieved.

The reset pulse generation block L11 is the output control block L
When the output time ts has elapsed due to the Q output of 10, a reset pulse is output from the Q output and output of the monostable multivibrator V2, and the peak hold control block L7
D latch DQ2, peak control block L9 D latch DQ3,
It is sent to the D latch DQ4 of the valley control block L8 and the D latch DQ5 of the input inhibition block L6 to reset them.

Next, the bottom output block A in FIG. 3 will be described in detail. FIG. 18 is a configuration diagram in which the bottom output block A is further divided into smaller blocks, and FIG. 19 is a circuit diagram thereof.
Of the signals input to the bottom output block A, the DC reproduction signal DC1 to be subjected to waveform processing is sent from the preprocessing block C in FIG. 3, and the other PC, ▲
The control signals represented by ▼ / T, BC1, ▲ ▼, ▲ ▼ are sent from the control block B.

The first peak hold block KL1 is operational amplifier OP13, OP
14, resistors R24 to R26, capacitors C10 to C12, diodes D5, D
6. It consists of a normally open analog switch NO1 and a normally closed analog switch NC1. The DC reproduction signal DC1 is input to the operational amplifier OP13 via the operational amplifier OP21 of the voltage follower,
The first peak hold value P / H is output from the operational amplifier OP14. In this case, if the normally closed analog switch NC1 is closed by the control signal ▲ ▼ / T, the peak hold value is not obtained and the output follows the input (tracking mode). When the normally closed analog switch NC1 is opened by the control signal ▲ ▼ / T, the output follows the input until the peak comes, but when the peak comes, the peak value is held (peak hold mode). FIG. 20 is a diagram showing, as an example, how the first peak hold block KL1 follows the near pass pulse SP when particles continuously pass through the pores. The normally closed analog switch NC1 is opened / closed by the control signal ▲ ▼ / T, the peak hold mode is entered when the control signal ▲ ▼ / T is L, and the tracking mode is entered when the control signal ▲ ▼ / T is H. In Figure 20, the first peak P /
After holding H, move to tracking mode to quickly follow the input waveform and move to the next peak P / H
You can see that you are holding faithfully.

On the other hand, the normally open type analog switch NO1 holds the first peak of the valley waveform signal and becomes H at the same time as the control signal.
It is closed by the PC (Fig. 16 (j)). For this reason,
As shown in Fig. 21, the positive input of the direct current reproduction signal DC1 input to the operational amplifier OP13 is forcibly dropped to zero potential, so that the first peak value is higher even if the second peak value of the valley waveform is higher. To be held. As a result, the first peak hold block KL1 outputs the first peak hold value P / H shown in FIG. This corresponds to the symbol M2 in FIG.

The first difference signal generation block KL2 is an operational amplifier OP15, a resistor
It is composed of R27 to R30. The direct current reproduction signal DC1 is subtracted from the first peak hold value P / H, and the first difference signal B1 is output as shown by the broken line in FIG. This is the code in Figure 1
Corresponds to M4. The first difference signal B1 is zero when the first peak hold block KL1 is in the tracking operation.

The second peak hold block KL3 is operational amplifier OP16, OP
17, resistors R31 to R33, capacitors C13 to C15, diodes D7, D
It consists of a normally open analog switch NO2 and a normally closed analog switch NC2. The basic operation of this second peak hold block KL3 is the first peak hold block K
It is the same as L1, and after the first peak of the first difference signal B1 is held, the positive input of the operational amplifier OP16 is forcibly dropped to zero potential by the control signal BC1 which becomes H at the position of the valley of the valley waveform signal. Therefore, the second peak hold block KL3 outputs the second peak hold value B / H shown in FIG. This corresponds to the code M5 in FIG. This second
The height h ₂ of the peak hold value B / H is equal to the depth h ₁ of the valley of the DC reproduced waveform D1.

The decision block KL6 is composed of an operational amplifier OP18, a normally-open analog switch NO3, a normally-closed analog switch NC3, and a resistor R34, and the normally-open analog switch NO3 is controlled by a control signal BC1 for detecting a valley. The closed analog switch NC3 is also controlled by the control signal ▲ ▼, so that in the case of the valley waveform signal as shown in FIG. 24 (a), the second peak hold value B / H is the second difference signal generation block KL4. However, in the case of a single peak waveform signal as shown in FIG. 7B, the positive input of the operational amplifier OP18 becomes zero potential.

The normally open analog switch NO3 and the normally closed analog switch NC3 are opened and closed at the timing shown in FIG. 25 by delaying the control signal ▲ ▼ from the control signal BC1 as described above, and the operational amplifier OP18 has a positive voltage. The second difference signal generation block KL
The output of 4 is temporarily prevented from becoming unstable.

The second difference signal generation block KL4 includes an operational amplifier OP19 and a resistor.
It is composed of R35 to R38, and in the case of a valley waveform signal, subtracts the second peak hold value B / H from the first peak hold value P / H,
The second difference signal B2 is output as shown in FIG.
This corresponds to the code M6 in FIG. Further, in the case of the single peak waveform signal of FIG.
The peak hold value P / H is output.

The output block KL5 is composed of an operational amplifier OP20, a resistor R39, and a normally closed type analog switch NC4, and outputs a second difference signal B2 having a desired peak value in a pulse waveform for a certain period of time in response to a signal.

26 to 30 show signal waveforms at various parts of the bottom output block A. The waveform of the dotted line in the figure shows the DC reproduction signal DC1.

FIG. 26 shows the case where the DC reproduction signal CD1 is a valley waveform signal. In this case, since the control signals BC1, ▲ ▼ are generated, the second peak hold value B / H is input by the determination block KL6, and the first peak hold value P / H and the second peak hold value P / H are input by the second difference signal generation block KL4. The peak hold value B / H is subtracted, and the peak value of the valley is output as described above.

Note that the waveform d ′ of the particle passage route d shown in FIG. 32 and FIG. 33 is processed in the same manner as the processing of the valley waveform signal as long as there is a flat portion in the portion corresponding to the valley of the valley waveform. , The flat portion is output as a peak value.

FIG. 27 shows the case where the DC reproduction signal DC1 is a single peak waveform signal. In this case, the control signals BC1, ▲ ▼ are not generated, and the second difference signal generation block KL4 outputs the first peak hold value P / H, that is, the peak value of the first peak of the DC reproduction signal DC1.

FIG. 28 shows a case where the direct current reproduction signal DC1 does not have a particle detection signal and has a waveform of only noise. In this case, since the noise is discriminated in the control block B, ▲
▼ / T signal is not generated and the peak is not held. Further, since the ▲ ▼ signal is not generated, the peak value is not output.

FIG. 29 shows the case where it is determined that the DC reproduced signal DC1 exceeds the reference signal Ref2 in the large signal, that is, the control block B. For example, this is the case when a large signal due to red blood cells or white blood cells is input in the platelet measurement. In this case, the control signal ▲ ▼ / T once falls to L and the first peak hold block KL1 enters the peak hold mode, but the DC reproduction signal DC1 exceeds the reference signal Ref2 before reaching its peak, so the control signal ▲ Since ▼ / T immediately returns to H and enters the tracking mode, the peak of the DC reproduction signal DC1 is not held. In addition, the crest value is not output because the ▲ ▼ signal is not generated. In this way, unnecessary red blood cell and white blood cell signals are removed, for example, when measuring platelets.

FIG. 30 shows the case where the DC reproduction signal DC1 is a return signal, but as described above, the peak is not held and the peak value is not output in this case as well.

FIG. 31 shows an example in which the particle size distribution of a blood sample is measured by the waveform processing device 9 of this embodiment. In FIG. 31, the horizontal axis represents the peak value and the vertical axis represents the frequency. The peak on the left side shows platelets, the distribution with a large crest value on the right side shows a part of the red blood cell particle size distribution, the solid line is the particle size distribution curve after the removal of the return signal, and the broken line is the particle size distribution curve before the removal of the return signal. , Since the return signal is removed by about 99% or more, the true particle size distribution with less distortion can be obtained.

(Effect of the Invention) According to the return signal removal device of the particle analyzer of the present invention, when the particle detection signal output by the detection means is due to the passage of particles through the pores, the signal rises rapidly, so Although the differential signal of the detection signal becomes larger than the particle detection signal, the differential signal of the Mai return signal does not become larger than the Mai return signal because the rise of the Mai return signal is slow. Therefore, the dance return signal determining unit compares the particle detection signal and its differential signal to determine the dance return signal, and the dance return signal removing unit removes the dance return signal from the processing target of the processing unit. There is an effect that the return signal can be removed more reliably.

[Brief description of drawings]

1 is a schematic explanatory view of the present invention, FIG. 2 is an explanatory view of a particle analyzer to which an embodiment of the present invention is applied, FIG. 3 is a block diagram of a waveform processing device, and FIG. 4 is a preprocessing block. FIG. 5 is a circuit diagram, and FIG. 5 is an explanatory diagram for explaining the cause of the generation of the return signal.
6 is a waveform diagram of the return signal and its differential signal, FIG.
Fig. 8 is a waveform diagram of the particle detection signal containing noise and its differential signal. Fig. 8 is a waveform diagram of the single peak waveform signal and valley waveform signal and their differential signals. Fig. 9 is a large signal of large particles Waveform diagram of return signal and differential signal,
Fig. 10 is a block diagram of the control block, Fig. 11 is a circuit diagram thereof, Fig. 12 is a waveform diagram of a partial block in the case of a valley waveform signal, and Fig. 13 is a waveform diagram of a partial block in the case of a single peak waveform signal. Waveform diagram, FIG. 14 is a waveform diagram of a partial block when a single peak waveform signal is continuous, FIG. 15 is a waveform diagram of a partial block when the platelets, erythrocytes and particles return, and 16
The figure is a waveform diagram of each part in the case of a valley waveform signal, FIG. 17 is a waveform diagram showing a particle detection signal and its differential signal when red blood cells are reflected back immediately after passing through pores, and FIG. 18 is a bottom. FIG. 19 is a block diagram of the output block, FIG. 19 is a circuit diagram thereof, FIG. 20 is an explanatory diagram showing a peak hold state, FIG. 21 is an explanatory diagram explaining a state where the first peak is held, and FIG. 22 is a first diagram. FIG. 23 is an explanatory diagram for explaining a state in which a difference signal is detected, and FIG.
24 is an explanatory view for explaining the state in which the peak of the difference signal is held, FIG. 24 is an explanatory view for explaining the output waveform of the second difference signal generation block, and FIG. 25 is an explanatory view for explaining the operation of the judgment block. Figure 26 is a waveform diagram of each part of the valley waveform signal, Figure 27 is a waveform diagram of each part of the single peak waveform signal, Figure 28 is a waveform diagram of each part in the case of noise, and Figure 29 is a particle detection signal for large particles. Fig. 30 is a waveform diagram of each part in the case of, Fig. 30 is a waveform diagram of each part in the case of a return signal, Fig. 31 is a characteristic diagram of the frequency with respect to the peak value of the signal output from the waveform processing device, and Fig. 32 is a particle Explanatory diagram for explaining the process of passing through the pores, FIG. 33 is a waveform diagram of the particle detection signal corresponding to each particle, FIG. 34 is an explanatory diagram for explaining the generation of the return signal, FIG. 35 is the return Fig. 36 is a waveform diagram of the signal and its differential reproduction signal. Fig. 36 is the waveform of the differential reproduction signal of the platelet detection signal. , Fig. 37 is an explanatory view for explaining the operation process when red blood cells are reflected back immediately after passing through the pores, Fig. 38 is a waveform diagram of the detection signal and a reproduction signal of its differential, and Fig. 39 is a granularity. It is a distribution curve figure. 1 ... Detection means, 2 ... Differential signal generation means, 3 ... Dance return signal determination means, 4 ... Processing means

Claims (1)

[Claims] 1. A detection means for outputting a particle detection signal generated as particles pass through a pore, a differential signal generation means for differentiating the particle detection signal and outputting a differential signal, and the particle detection signal. And a return signal determining means for comparing the differential signals and outputting a signal for determining the particle detection signal as a return signal when the differential signal is smaller than the particle detection signal; and processing the particle detection signal. Also, a return signal removal of a particle analysis device comprising: a processing unit having a return signal removal unit that removes the particle detection signal that becomes the return signal according to the signal determined to be the return signal of the return signal determination unit. apparatus.