JPS5841336A - Particle analyzer - Google Patents

Abstract

PURPOSE:To obtain an accurate measurement value for particles other than ball- shaped by adding information of width of a particle signal to that of height. CONSTITUTION:A particle detecting device 5 produces a particle signal 19 which is fed to a peak hold circuit 6 and a comparator 7. An AD conversion circuit 8 produces a saw-tooth signal 21 at the peak value 20 of the signal 19 held at the circuit 6 and produces a gate signal 23 up to the point 22 to pass a reference pulse A so that a signal D with the number of pulses corresponding to the height of the signal 19 is obtained. The circuit 7 passes the particle signal with a voltage higher than the output voltage from the reference voltage generator 10 delivering gate signal C to the gate circuit 9 and counts the number of particles at a counter 11. After AD conversion of each particle signal, it is fed to the circuit 6 via a reset signal 25. The signal C with the information about the width is passed through the pulse A as a gate signal obtain a pulse E. The AD-converted value and the output from the circuit 9 thus obtained are operated at an operator 13 and accumulated at an accumulator 14. This is divided by the value of the circuit 11 to obtain the average particle volume.

Description

Detailed Description of the Invention The present invention allows a liquid in which particles such as blood cells are suspended to pass through pores, detects changes based on electrical differences between the particles and the liquid, and detects changes in the number and average size of particles. In particular, this invention relates to a particle analyzer that can more accurately determine the volume of particles other than perfectly spherical.

Conventionally, particle counting devices have used the pulse height of a detection signal as information regarding the size of a measured particle. That is, as shown in FIG. 1, if the pulse height of the detection signal when a small particle 2 passes through the detector pore 1 is h1, and the pulse height of the detection signal when a large particle 3 passes is h'. , h' are larger than h, and the pulse height of the detection signal is proportional to the volume of particles passing through the detector pore 1. By measuring the average height of this pulse height, the average volume of particles such as blood cells was determined.

For example, the mean corpuscular volume (MCV) was calculated using the following formula.

MCV=to-h (1) where π times the average pulse height, K is a constant.

However, when measuring cells that are not perfectly spherical, such as red blood cells, there is a problem in that the pulse height of the detection signal changes even though the volume is the same, causing errors. That is, as shown in FIG. 2, the pulse height of the detection signal when the red blood cell 4 passes sideways through the detector pore 1 is h+,
Let the pulse width be h2, the pulse height of the detection signal when the red blood cell 4 passes vertically be h2, and the pulse width be t2, then h
2 was larger than b+, and tl was larger than t2, resulting in an error.

As a method to reduce this error, a so-called sheath method has been devised that uses fluid dynamics to allow blood cells to pass only through the center of the pore, but this method has had problems such as a complicated structure.

The present invention was developed in view of the above points, and takes advantage of the fact that the time it takes a particle to pass through a detector pore is relatively correlated with the size of the particle in the passing direction, and the width of the particle signal is adjusted to the height. It is an object of the present invention to provide a particle analyzer that can obtain more accurate measurement values even for particles other than spherical by adding information.

Hereinafter, the configuration of the present invention will be explained based on the drawings.

FIG. 4 shows the configuration of an example of the particle analyzer of the present invention, and FIG. 5 shows the operation. From the detection signal shown in FIG.
This is based on an example case in which measurements are performed as shown in the following equation.

Information proportional to volume = h + K t (2) where h is the pulse height of the detection signal, K is a constant, and t is the transit time (pulse width). In this case, K differs from the measurement result of perfectly spherical particles by measuring flat-shaped particles such as red blood cells over various sizes and calculating the correlation diagram with =O for each particle size. 45
The value of K is determined by finding the correction value necessary to correct this to 45° (see FIG. 3). Therefore, the value of K varies depending on the shape of the particle to be measured. For example, when used for industrial particles with a rod-like external shape, a correlation diagram is similarly obtained using known particles and known spherical particles, and the Determine the value of K.

As shown in FIG. 4, the particle analyzer of the present invention detects particles based on the electrical impedance difference or optical difference between the particles and the liquid by passing the liquid in which the particles are suspended through the pores. A particle detection device 5 that generates an electric signal proportional to the size, a peak hold circuit 6 and a comparison circuit 7 connected to the particle detection device 5, and an AD conversion circuit 8 connected to the peak hold circuit 6. , a gate circuit 9 connected to the comparator circuit 7, a reference voltage generation circuit lO, and a counting circuit 11.
, a reference pulse generation circuit 12 and an arithmetic circuit 13 connected to the gate circuit 9 and the AD conversion circuit 8, an accumulator circuit 14 connected to the arithmetic circuit 13, and an accumulator circuit 1.
4 and a division circuit 15 connected to the counting circuit 11, and display circuits 16, 17, and 18 connected to the accumulation circuit 14, the division circuit 15, and the counting circuit 11, respectively.

Particle detector IFi emits a particle signal as shown at the top of FIG. 5, and sends the signal to peak hold circuit 6 and comparison circuit 7. The AD conversion circuit 8 generates a sawtooth signal 21 in response to the peak value 20 of the particle signal 19 held in the peak hold circuit 6, and detects a point 22 that coincides with the peak value 20.
A gate signal 23 is generated up to and a reference pulse A is passed. This signal is D. Therefore, a signal having a number of pulses corresponding to the height of the particle signal 19 is obtained, and the accumulated signal is related to the conventional particle volume measurement. On the other hand, the comparator circuit 7 passes a particle signal of a predetermined voltage level, that is, a voltage higher than the output voltage 24 of the reference voltage generation circuit IO, and generates a gate signal C, and sends the gate signal to the gate circuit 9. In addition, the counting circuit 11
Count the number of particles. When AD conversion is completed for one particle signal, it is sent to the peak hold circuit 6 via a reset signal 25. The signal C sent to the gate circuit 9 is also information regarding the width of the signal, and is used as a gate signal to allow the reference pulse A to pass. In other words, the pulse E according to the signal width
is obtained. The AD conversion value and the output value of the gate circuit 9 obtained in this way are subjected to the calculation of the above formula (2) by the calculation circuit 13, and the accumulation circuit 14 performs the accumulation of each particle signal one after another. It will be done. Measurements are performed on a predetermined object to be measured, and the final value obtained is a value related to the total volume of particles, so by dividing by the value of the counting circuit 11 that counts the number of particles,
The average particle volume is determined. The value is obtained by the division circuit 15. The respective values are displayed on display circuits 16, 17, 18. If the particle is a red blood cell, the display circuit 16.1
7.18 hematocrit values (HCT),
Displays mean corpuscular volume (MCV) and red blood cell count (RBC).

Since the particle analyzer of the present invention is configured as described above, it is possible to obtain more accurate particle volume information even for non-spherical particles such as red blood cells, and the fluid system (particle detection device) Since this method is based on a circuit improvement without making any improvements, it has the advantage that it can be easily incorporated into a particle counting circuit such as a conventional hemocytometer.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram showing the detection signal when a small particle passes through the detector pore and the detection signal when a large particle passes through it, and Figure 2 shows the detection signal when a red blood cell passes sideways through the detector pore. FIG. 3 is an explanatory diagram showing the detection signal when a red blood cell passes vertically, FIG. 3 is an explanatory diagram for determining the constant K, and FIG. 4 is an embodiment of the particle analyzer of the present invention. Systematic explanatory diagram, FIG. 5 is an explanatory diagram of operation. 1...Detector pore, 2...Small particle, 3...Large particle, 4...Red blood cell, 5...Particle detection device, 6...Peak hold circuit, 7...Comparison Circuit, 8... AD conversion circuit, 9... Gate circuit, 10... Reference voltage generation circuit, 11... Counting circuit, 12... Reference pulse generation circuit, 13... Arithmetic circuit, 14 ...cumulative circuit, 15
...Division circuit, 16.17.18...Display circuit, 1
9... Particle signal, 20... Peak value, 21... Sawtooth signal, 22... Match point, 23... Gate signal,
24... Output voltage, 25... Reset signal Patent applicant Toa Medical Electronics Co., Ltd. Figure 2

Claims (1)

[Claims] 1 A particle detection device that detects particles by passing a liquid in which particles are suspended through pores based on electrical or optical differences between the particles and the liquid and generates an electric signal proportional to the size of the particles; A peak hold circuit and a comparison circuit connected to the particle detection device, and an A connected to the peak hold circuit.
D conversion circuit, gate circuit connected to comparison circuit, reference voltage generation circuit and counting circuit, gate circuit and AD
a reference pulse generation circuit and an arithmetic circuit connected to a conversion circuit, an accumulation circuit connected to this arithmetic circuit, a division circuit connected to this accumulation circuit and the counting circuit, an accumulation circuit, a division circuit, and a counting circuit; A particle analysis device comprising a display circuit connected to each circuit.