JPS60186728A - Calibrating device of pressure and flow velocity measuring device - Google Patents

Abstract

PURPOSE:To perform calibration before measurement by providing a pressure derector and a flow velocity detector in a vent pipe connected to a pipe to be measured, and a known resistor connected to one terminal of the vent pipe and an air supply means for a specific amount of air connected to the other terminal. CONSTITUTION:A mesh screen 2 is provided in the vent pipe 1 connected to the pipe to be measured and a flow velocity transducer 3 and a pressure transducer 5 are fitted. The resistor 7 whose resistance value is already known is connected to one terminal of the vent pipe 1 and a supplier 8 for a specific amount of air is connected to the other terminal. The flow velocity and pressure from the air supply of the supplier 8 to the end are stored in RAM15 by a CPU13 through AD converters 4 and 6. The CPU13 calculates the total amount of passing air from the stored values and calculates the ratio to a specific value to calculate a coefficient of flow velocity calibration and further calculate a coefficient of pressure calibration. Both coefficients are stored and the flow velocity and pressure detected by the transducers 3 and 5 are calibrated on the basis of the stored values.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a calibration device that calibrates the measured values of a pressure/flow rate measuring device that measures flow rate.

The measuring device i¥ is used, for example, when diagnosing the respiratory system of the human body. In this case, the measuring device includes a pressure transducer connected to a measuring point in the respiratory system via a conduit, and a differential pressure flow meter (internally connected to the respiratory system). A vent pipe equipped with a resistor that detects the difference in pressure between two points sandwiching the resistor) and a differential pressure flow meter that outputs data indicating the flow rate based on the differential pressure given. It is equipped with a transducer for flow velocity. It is necessary that the pressure and flow rate values obtained by such measuring devices be accurate. For this reason, conventionally, before actually using a measuring device, it has been manually calibrated using a pressure gauge (particularly a liquid column pressure gauge) or a flowmeter (area type flowmeter).

However, although the calibration performed using such pressure gauges and flow meters is accurate, it cannot be said to be easy for anyone to perform and is inconvenient.

The present invention was made to eliminate such inconvenience, and its purpose is to quickly perform the above measurements by simply performing simple operations before making actual measurements using a pressure/flow rate measuring device. An object of the present invention is to provide a calibration device capable of performing calibration.

Therefore, in the present invention, during measurement, a resistor whose resistance value is known is connected to one end of the ventilation pipe connected to the pipe to be measured, and a predetermined amount of gas is supplied from the other end, from the time when this gas supply starts to the end. Calculate a flow rate calibration coefficient from the predetermined amount and the temporal change in the flow rate by storing the temporal change in the flow velocity in the ventilation pipe during the period, and storing the pressure in the ventilation pipe at a predetermined point in the period. A pressure calibration coefficient is calculated from this flow velocity calibration coefficient, the flow velocity and pressure at the above-mentioned predetermined time, and the resistance value of the resistor, and this is memorized, and it is detected during actual pressure/flow velocity measurement. The above object was achieved by calibrating the pressure and flow rate based on the pressure calibration coefficient and the flow rate calibration coefficient.

An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a ventilation pipe, and a mesh screen 2 is provided inside this ventilation pipe 1. As shown in FIG. 2 in the ventilation pipe 1 divided by this mesh screen 2
The pressure in each of the two sections is directed to a flow rate transducer 3.

The flow velocity transducer 3 outputs an electrical signal according to the flow velocity based on the difference between the two pressures introduced. This electrical signal is digitized by an A/D converter 4. The mesh screen 2, the flow velocity transducer 3,
The A/D converter 4 constitutes a flow rate detection device. 5 is a pressure transducer. Pressure transducer 5
is connected to the side of the ventilation pipe 1 where the pipe to be measured is attached, and converts the pressure inside the ventilation pipe into an electrical signal. This electrical signal is digitized by an A/D converter 6.

The pressure transducer 5 and the A/D converter 6 constitute a pressure detection device. A resistor 7 having a known resistance value R is connected to one end of the ventilation pipe 1 on the side where the pipe to be measured is attached. This resistor 7 has a plurality of thin tubes inside. A gas supply device 8 is connected to the other end of the ventilation pipe 1 . The gas supply device 8 includes a cylinder 9 and a piston 10.
When the operator of this device presses the piston 10 via the piston shaft 11, a predetermined amount of gas (500 cc) can be accurately delivered to the ventilation pipe.
It is intended to supply A microcomputer 12 is composed of a CPUI 3, a ROMI 4, a RAM 15, an interface 16, and an internal path 17 connecting these. The CPU 13 performs data processing by exchanging data with the RAMI 5 and the interface 16 based on a program stored in the ROM 14.

An A/D converter 4.6 is connected to the interface 16, and a flow rate transducer 3,
Flow rate data output from the pressure transducer 5,
Pressure data is now provided. ROM14
A flowchart of the program stored in the computer is shown in FIG.

Further, a key gate 18 is connected to the interface 16, and the key gate 18 also controls the microcomputer 1.
2 can be entered.

Furthermore, a cathode ray tube display 19, a printer 20, and a monitor 21 are connected to the interface 16. The data processed by the micro combinator 12 is displayed or printed here.

The overall configuration of the device of this embodiment is shown in a functional block diagram as shown in FIG. 3.

Next, the operation of the apparatus of this embodiment will be explained according to chart 70 in FIG.

First, when the operator of this device starts supplying a predetermined amount of gas (5000C) to the gas supply device 8, the CPU 13
detects the start of gas supply at Stella 7°101 and returns Stella f.
Proceeding to step 102, from this start time (1=0), every unit time (10 masc), the flow velocity transducer 5-
The flow rate data and pressure data given to the interface 16 from the sensor 3 and the pressure transducer 5 via the A/D converters 4 and 6 are respectively transferred to areas Ml and M2 of the RAM 15.
Store in. This process is continued until the stesonometer 103 determines that the gas supply has ended (t=T). Next, the CPU 3 proceeds to the step controller 104, where the process starts from the time when the gas supply starts (1=0) to the time when the supply ends (
The total amount S of gas supplied to the ventilation pipe 1 until t=T) is
It can be calculated using the data (flow velocity t per unit time) stored in area M1 of the RAM 15. That is, CPU13
calculates the following equation.

Next, the CPU 13 calculates the total f calculated in step 104 above.
The ratio α between IkS and the amount of gas 500CC supplied from the gas supply device 8 to the trachea 1 is determined by the formula 1:5.

That is, the CPU 13 calculates the following equation.

This ratio α becomes the flow rate calibration coefficient.

Then, in step 106, the CPU 13 calculates the flow velocity calibration coefficient α.
is stored in area M3 of RAM 15.

Next, the CPU 13 proceeds to the stesono 107, where the predetermined time point T! Flow velocity v1ζRAM1 at (0≦T1≦T)
5 from area M1, and multiplying it by the above-mentioned flow velocity calibration coefficient α to obtain the correct (calibrated) value at a predetermined time point T□.
Set the flow rate to 91gTD.

That is, the CPU 13 calculates the following equation.

Sentence IBTD = αM.

Next, the CPU 13 is Stella 7'. Proceeding to 108, where the correct (calibrated) pressure P18T at a predetermined time T1
D can be calculated from the flow velocity v1jlTD. This calculation is performed using the following equation since the resistance value R of the resistor 7 connected to the ventilation pipe 1 is known.

PlllTD "R" JIBTD Then, the CPU 3 proceeds to step 109 and selects the pressure P1aTD obtained in the previous stesono 108 and the pressure data stored in the area M2 of the driving factor 15 at a predetermined time point T1.
A pressure calibration coefficient β is calculated based on the ratio between the pressure P1 and the pressure P1. That is, the CPU 3 calculates the following equation.

1 Next, the CPU 13 proceeds to the stesonometer 110 and stores the requested pressure calibration coefficient β in the area M4 of the RAM 15. Then CPU 3 determines step 11 whether measurement preparation is complete.
Go to 1. Here, the resistor 7 and the gas supply device 8 are removed from the ventilation tube 1, and the ventilation tube is inserted, for example, into the respiratory system of the subject.
is connected and measurement preparations are completed, the CPU 13 proceeds to the controller 112, and thereafter stores the flow velocity and pressure data given to the interface device 6 in the area M of the RAM 15.
3. Calibration is performed by multiplying M4 by a flow velocity calibration coefficient α and a pressure calibration coefficient β stored respectively.

The flow rate and pressure data calibrated in this way are processed by the CPU 3 based on the instructions from the key 18 and the other grodarum (stored in the ROM 14), and sent to the cathode ray tube display 19 and the printer 2o. Output.

As described above, according to this embodiment, the measured values of pressure and flow rate can be easily calibrated by simply installing a simple instrument (by simply changing or adding software to the inside of the measuring device).

As described above, according to the present invention, pressure and flow velocity can be quickly calibrated by simple operations when measuring pressure and flow velocity using a pressure and flow velocity measuring device.

[Brief explanation of drawings]

FIG. 1 is a block diagram for explaining one embodiment of the present invention, FIG. 2 is a flowchart showing a program stored in the ROM shown in FIG. 1, and FIG. 3 shows the entire embodiment device. It is a functional block diagram. 1...Vent pipe, 2...Metsushiko screen, 3...
・Flow velocity transducer, 5... Pressure transducer, 7... Resistor, 8... Gas supply device, 12
...Microcomputer, 13...CPU, 14
...ROM, 15...RAM, 16...Interface. Agent Patent Attorney Book 1) Takashi Diagram 2

Claims (1)

[Claims] A pressure detection device that detects the pressure of the gas at one point in the ventilation pipe, in a calibration device for a pressure/flow velocity measuring device that includes a ventilation pipe connected to a pipe to be measured and measures the pressure and flow velocity of gas inside the pipe to be measured. a flow velocity detection device for detecting the flow velocity of gas flowing in the ventilation pipe; a resistor connected to one end of the ventilation pipe and having a known resistance value; and a resistor connected to the other end of the ventilation pipe and provided with a predetermined amount of a gas supply means for supplying the gas, and a flow velocity storage means for storing the flow velocity detected by the flow velocity detection device from the time when the gas supply means starts supplying the gas to the vent pipe to the time when it ends, with time.
a pressure storage means for storing the pressure detected by the pressure detection device at a predetermined point in time; and a flow rate stored in the flow rate storage means and a time corresponding to the flow rate stored in the flow rate storage means. a flow velocity calibration coefficient calculation means for calculating a flow velocity calibration coefficient by calculating the ratio between the total amount of gas calculated by the total volume calculation means and the predetermined amount; a flow velocity calibration coefficient storage means for storing a flow velocity calibration coefficient; and calculating the pressure at the predetermined time point based on the flow velocity calibration coefficient, the resistance value of the resistor, and the flow velocity at the predetermined time point stored in the flow velocity storage means. and a pressure calibration coefficient that calculates a pressure calibration coefficient by calculating the ratio between the pressure requested by the pressure calculation means and the pressure at the predetermined time point stored in the pressure storage means. a calculation means; a pressure calibration coefficient storage means for storing the pressure; 1. A calibration device for a pressure/flow rate measuring device, comprising a calibration means for respectively calibrating pressure.