JPS5949529B2 - Platelet measuring device - Google Patents

Description

[Detailed description of the invention] Mr. Bull's HCT correction coefficient HCT correction coefficient, 28.66. 20.78. 29.65. 21.77. 30.63. 22.75. 31.61. 2 3, 7 4. 3 2, 60. 2 4 , 7 3 This invention relates to a device for measuring the number of platelets in blood.

The platelet count is generally expressed as the number of platelets in blood, but since it is difficult to count only platelets when red blood cells and white blood cells are uniformly dispersed, conventionally, red blood cells, etc. are precipitated. The platelets in the platelet-rich serum, which is the supernatant obtained, were counted, and the number of platelets in blood 1 was estimated from this.

One example of this technique is to prepare blood with an anticoagulant as shown in Figure 1a.
The tube container 1 shown in FIG.
Take out platelet-rich plasma, dilute it to a predetermined ratio with saline, apply it to an electric particle counter, calculate the number of platelets contained in Sample 1 before dilution, and calculate the number of platelets that are related to the hematocrit value HCT. The measured value of platelet count is obtained by multiplying by Mr. Bull's correction coefficient.

The measured value obtained in this manner closely matches the number of platelets uniformly dispersed in the actual blood, and the above-mentioned correction coefficient is as follows. Yat B HCT correction coefficient HCV correction guide], 44.40. 36.52. 45.39. 37.50. 46.38. 38.48. 4 7, 3 7. 3 9, 4 7. 4 8, 3 6. 40, 4 5. 4 9 , 3 5 . 41, 4 4. 5 0, 34. 4 2 , 4 2 . 4 3 , 4 1 Hematocrit value HCT indicates the total volume of red blood cells.

When blood is placed in a capillary container 1 and subjected to strong centrifugation, the first
As shown in Figure b, the blood is separated from the bottom into an erythrocyte precipitate part 2, a leukocyte precipitate part 3, a platelet precipitate part 4, and a serum 5, and the volume of the erythrocyte precipitate part at this time is the hematocrit value HCT. In the conventional measurement method described above, in many cases the hematocrit value has already been measured as part of the blood test, so there is no problem in using it, but Mr. Bull's Determining the correction coefficient and multiplying it by the count value of the particle counter is as follows:
It is complicated and difficult to implement in large hospital laboratories and laboratories that handle a large number of specimens, and it has the disadvantage that abnormal specimens cannot be detected immediately because the platelet count cannot be determined until it is multiplied by a correction coefficient.

In order to improve this shortcoming and directly read the platelet count, we are considering incorporating into the particle counter a matrix circuit that calculates Bull's correction coefficient from the hematocrit value and a multiplication circuit that multiplies the platelet count by the calculated correction coefficient. However, the configuration of the device becomes complicated and the price increases.

The object of the present invention is to directly display the correct platelet count corrected based on Bull's coefficient using a simple configuration.

The platelet measuring device according to the present invention distributes a predetermined amount of a sample prepared by diluting platelet-rich plasma separated from blood to a predetermined ratio, and obtains a particle detection pulse every time particles contained in the sample pass. It has a detection device.

This particle detection pulse includes pulses corresponding to white blood cells, red blood cells, and platelets, and each has a different wave height, so the pulse height discrimination means selects only the pulse with the wave height corresponding to platelets as a platelet detection pulse. Extract. After this platelet detection pulse is divided by a variable frequency divider,
The count is displayed. Here, the frequency division ratio of the variable frequency divider is determined by the frequency division ratio control circuit according to the hematocrit value of the same blood sample that is input separately. To explain in more detail, generally there are 20 platelets in 1d of blood.
Platelet-rich plasma contains ~300,000 platelets, and platelet-rich plasma contains two to three times as many platelets, and the number of platelet detection pulses normally obtained by a detection device is far smaller than that. , is in a proportional relationship with it.

Furthermore, although the number of pulses counted is even smaller due to frequency division, there is still a proportional relationship. Therefore, if the dilution ratio and amount of the sample to be supplied to the detector are appropriately selected, and the frequency division ratio at the time of frequency division is changed according to Bull's coefficient corresponding to the hematocrit value, the above counted value can be reduced. is an integer power of 10, such as 1/100, 1/1000, or 1/10000 of the number of platelets contained in 1 md of blood.
Therefore, the number of platelets in blood Ii can be directly read from the above count value. The present invention will be explained below based on illustrated embodiments.

In FIG. 2, numeral 11 is a particle detection device that allows a diluted solution of the platelet-rich plasma 4 shown in FIG. A pulse train as shown in FIG. 3 is generated in response to passing particles by changing the rate.

In FIG. 3, 6 indicates a noise pulse, 7 indicates a platelet detection pulse, and 8 indicates a red blood cell pulse.

1J of normal human blood! There are several million red blood cells in J.
Several thousand leukocytes and 200,000 to 300,000 platelets are included, but as can be seen from this, the thickness of the leukocyte precipitated region 3 and the platelet-rich plasma 4 in FIG. 1 is extremely thin. Therefore, the sample obtained from the centrifuged platelet-rich plasma 4 also contains some red blood cells, as shown in FIG. 3, and also contains a small amount of white blood cells. 12 and 13 are discriminators, and the pass level is set to E1 so that the discriminator 12 does not pass the platelet detection pulse 7 but allows the red blood cell detection pulse 8 and the larger white blood cell detection pulse to pass. The pass level of the discriminator 13 is set to E so that the noise pulse 6 is not passed, but the platelet detection pulse 7, the red blood cell detection pulse 8, and the white blood cell detection pulse are allowed to pass.

Both passing signals are processed by an exclusive OR circuit 14, and the output thereof is frequency-divided by a variable frequency divider circuit 15, counted by a counter 16, and displayed. 17 is a control circuit that determines the frequency division ratio of the variable frequency divider circuit 15;

This accepts a signal indicating the magnitude of the hematocrit value HCT obtained through separate measurement, obtains the aforementioned Bull's correction coefficient using, for example, a matrix circuit, and adjusts the circuit 15 to correspond to this correction coefficient. Control the division ratio. Here, the counter 16 is to read the counted value by multiplying it by 1000, and the platelet-rich serum 4 is the sample 2 diluted 5000 times.
It is assumed that measurement by the particle detector 11 is performed for 50 m71.

In this case, 1 m of platelet-rich plasma 4! In order for the counter 16 to read the number of platelets contained in L, the frequency division ratio of the variable frequency divider circuit 15 must be 1/50. Therefore, the frequency division ratio of the circuit 15 is controlled based on this 1/50. Suppose that the hematocrit value of the blood sample is 44.
%, the signal indicating this value is the control circuit 1
7, a correction coefficient of 0.4 corresponding to this hematocrit value is selected in the control circuit 17, and the above-mentioned reference frequency division ratio of 1/50 is multiplied by this correction coefficient.

Thus, the control circuit 17 controls the frequency division ratio of the variable frequency divider circuit 15 to 1/125. If 500,000/Mii platelets are present in the platelet-rich plasma 4 of the sample, the 5000-fold diluted solution 2 detected by the particle detector 11
Since there are 25,000 platelets in 50 md, 25,000 pulses are input to the variable frequency dividing circuit 15,
The frequency is divided into 1/125, resulting in 200 pieces, which are counted by the counter 16 and displayed.

As mentioned above, the value displayed on the counter 16 is multiplied by 1000 and read, so the read value is 200,000 pieces/MiL. The amount of platelets in platelet-rich plasma 4 in the above example, 500,000/U
Since the amount of platelets in the blood calculated from i and the correction coefficient 0.4 when the hematocrit value in Mr. Bull's chart B is 0.44 is 200,000/1n71, the number of platelets in the counter 16 described above is The readings match this.

As is clear from the above description, according to the present invention, platelets can be measured directly.

In order to correct the counted value, no multiplication circuit is used, and only the frequency division ratio of the frequency divider installed in front of the counter, which is conventionally used in blood cell measuring devices, etc., is changed. By providing a switch circuit for changing the interconnection of the frequency dividers, a desired frequency division ratio can be obtained by controlling the switch circuit, and the purpose can be achieved with a simple configuration. In addition, if you change the sample dilution factor or the amount of sample measured during particle detection, you can easily make adjustments so that you can directly read the correct platelet count by simply modifying the frequency division ratio. be.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of separated blood components, FIG. 2 is a block diagram of an embodiment of the present invention, and FIG. 3 is a waveform diagram of blood particle detection signals. 11...Particle detector, 12 and 13...
- Discriminator, 14... Exclusive OR circuit, 15... Variable frequency divider, 16... Counter, 17... Frequency division ratio control circuit.

Claims (1)

[Claims] 1. A detection device that distributes a predetermined amount of a sample prepared by diluting platelet-rich plasma separated from blood to a predetermined ratio and obtains a particle detection pulse each time a particle contained in the sample passes;
a pulse height discriminator for extracting only pulses with wave heights corresponding to platelets from the train of particle detection pulses as platelet detection pulses; a variable frequency divider for dividing the frequency of the train of platelet detection pulses; It consists of a frequency division ratio control circuit that determines a frequency ratio, and a device that counts and displays the pulse train frequency-divided by the variable frequency divider, and the number of pulses output by the variable frequency divider is determined by the unit of the platelet-rich plasma. The frequency division ratio control circuit is configured to determine a different frequency division ratio depending on the hematocrit value so that the frequency division ratio is equal to the upper digit part of the multiplicative product of the number of platelets in the volume and the correction coefficient based on the hematocrit value of the blood. Platelet measuring device.