JPH0446179Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to an ultrasonic liquid meter that can instantly measure the amount of liquid in a container using ultrasonic waves. This invention relates to a liquid meter for measuring quantity.

[Conventional technology and its problems] The urination of patients in hospitals etc. contains an extremely large amount of information regarding various internal diseases and the functions of the circulatory system. Especially in kidney-related diseases, it is difficult to accurately measure the amount of urination. It is extremely important to test.

Conventionally, in hospitals, inpatients urinate in a designated container and then transfer the urine from the container to a plastic bag with a different scale to collect urine. Measurements are taken hourly (for example, throughout the day) to check the patient's health condition.

However, the method in which nurses read each patient's collected urine and record it by hand has the disadvantage of not only poor work efficiency but also lack of accuracy, and the long measurement time interval makes it difficult to accurately determine the patient's health status. It was difficult to do so, and shortening the interval had the disadvantage of increasing the burden on nurses. Particularly in tests that require accurate measurement of urine volume to the nearest cc, such as creatinine clearance tests,
Conventional methods of simply reading numerical values from a beaker lacked accuracy.

[Purpose of the invention] This invention was devised in view of the above points.
It is an object of the present invention to provide a liquid meter that can measure liquid easily and accurately.

[Summary of the invention] The invention consists of a container containing a liquid to be measured, a transmitter that transmits burst-shaped ultrasonic waves of 250 KHz or more toward the liquid to be measured in the container, and a receiver that receives the signal. , hold the transmitter and receiver flush,
A mounting plate that can be attached to the liquid meter body so that it is horizontal to the liquid to be measured in the container and whose angle can be freely adjusted using an adjustment screw, and a mute plate that prevents ultrasonic waves from directly jumping from the transmitter to the receiver. The time from when the ultrasonic wave is transmitted until it is reflected from the bottom of the container and transmitted is calculated in advance.Then, the liquid to be measured is placed in the container, and the ultrasonic wave is transmitted and received toward the liquid. The time is determined, and the amount of liquid in the container is determined from the difference from the above-mentioned time.

[Example] Hereinafter, an example of the present invention will be described based on the drawings.

FIG. 1 is a diagram explaining the principle of the ultrasonic liquid meter of the present invention. When the burst-shaped ultrasonic waves shown in FIG. 2 are transmitted from the transmitter A toward the container C containing the liquid to be measured at an angle θ, The sound wave is 100% reflected and received by receiver B with the waveform shown in FIG. By measuring the time τ from transmission to reception at this time and multiplying it by the speed of sound c, the distance from the mounting position of transceiver A and B to the liquid level in the container can be calculated.

Here, the distance from this transceiver to the liquid level is d
Then, d=(τ×c×cosθ)/2.

The speed of sound c is expressed as c=331, 5+0, 6t [m/s] (where t is the temperature in degrees Celsius). Therefore, by providing a sensor that measures the temperature of the atmosphere between the transceiver and the container, the speed of sound c can be accurately obtained, and the distance d can be determined by calculating cos θ.

Furthermore, if the distance D from the transmitter/receiver to the bottom of the container is determined in advance by the same measurement as above or by mechanical or other methods, the depth of the liquid to be measured can be expressed as (D-d), and from this, the depth of the liquid to be measured can be expressed as (D-d). The volume S of the liquid to be measured can be determined as follows: S=(D-d)×s (1) (where s is the bottom area of the container).

By performing the above calculations using all microcomputers, the results can be obtained accurately and in a short time.

The above-mentioned ultrasonic wave shall be an ultrasonic wave of 250 KHz or more.
This is because conventional distance measurement using ultrasonic waves
Ultrasonic waves of 30 to 50 KHz are normally used, but when determining the volume as in the present invention, the volume changes greatly due to a slight difference in distance, so it is necessary to accurately determine the distance. For this reason, it is preferable to use ultrasonic waves of as high a frequency as possible, and the above frequency was obtained as a result of various experiments.

FIG. 4 is a block diagram of the present invention. The oscillator output of the above frequency is converted into the burst wave shown in FIG. and applies it to the ultrasonic transmitter 4.

On the other hand, the transmitted burst wave is reflected on the liquid surface of the liquid to be measured and generates a voltage on the ultrasonic receiver 5 side. At this time, a mute 6 is applied for a certain period of time created by the timing generation circuit 2 so as not to jump directly from the transmitter 4 to the receiver 5. As a result, the signal after being applied with the miute 6 is only the reflected signal. The amplifier 7 is used to improve the effect of the mute 6.

Also, the amplitude of the reflected wave changes depending on the distance to the liquid surface, so in order to make it constant, the envelope shape is applied to the AGC circuit 8 to keep the amplitude constant regardless of the distance, and the echo returns. Comparator 1 calculates the peak of the wave from a predetermined number from
0 to determine the rise of the reflected wave (see Figure 3). Note that the amplifier 9 amplifies the signal so that sufficient AGC is applied.

Thereafter, the flip-flop 11 generates a pulse corresponding to the time from when it is transmitted until when the comparator 10 turns on. This is added to a counter (16 bits) 12 to measure time, and the result is sent to a microcomputer 13.

The measurement results from the temperature sensor are also sent to the microcomputer 13, and the height d to the liquid surface is determined from the two measurement results, thereby calculating the depth of the liquid and the volume of the liquid. .

The result will be displayed on the LED and printer as necessary.

FIG. 5 is a flow chart thereof.

Figure 6 is a block diagram of a device using the ultrasonic liquid meter of the present invention for measuring urine, and in this figure, reference numeral 21
22 is the mounting part 2 of the liquid meter main body 21.
Urine, which is the liquid to be measured, is stored in a removable beaker 1a. The beaker 22 is not limited to the cylindrical shape shown in the figure, but may have any shape such as a tapered shape or a thick-tipped shape. It goes without saying that equation (1) for determining the volume of the liquid changes depending on the shape of the container.

23 is a transmitter that transmits ultrasonic waves to the urine in the beaker; 24 is a receiver that receives the ultrasonic waves;
It is attached to a plate 25 located above the beaker 22 and fixed to the liquid meter main body 21.

The mounting plate 25 has adjusting screws 26 provided on the left and right sides.
It is constructed so that the inclination can be adjusted forward and backward, left and right, and up and down, so that it can be adjusted so that it is always parallel to the urine in the beaker.

A temperature sensor 27 is provided on the mounting plate 25 and measures the temperature of the atmosphere between the transceivers 23 and 24 and the beaker 2. 28 is a numerical display section, 29 is a light emitting diode section (LED), 30 is a measurement start switch, and 31 is a power switch.

Next, the operation of this embodiment will be explained.

Hospitalized patients can either urinate directly into the beaker 22 or urinate into another container and then insert the funnel 32 into the beaker 22.
storage via. Next, when the measurement start switch 30 is turned on, the transmitter 23 transmits ultrasonic waves to the urine in the beaker, and the receiver 24 receives the ultrasonic waves. The time from when this ultrasonic wave is transmitted until it is received is calculated by a microcomputer (not shown) provided inside the liquid level meter main body 1, and the urine in the beaker is measured, and the display unit 28 and LED 29
This is what is displayed on the page. Furthermore, data can be recorded by connecting a recording device to the liquid meter main body 21 as needed.

According to this embodiment as described above, an accurate amount of urine can be obtained by simply setting the beaker in a predetermined position and pressing a switch. The system can measure urine volume, reducing the burden on nurses. In addition, you can print a record of the amount of urine produced each time you urinate, if necessary.
Compared to the conventional method in which a nurse collects urine and reads the amount of urine from a scale one by one and records it, the method has the advantage of being able to quickly and accurately respond to a patient's medical condition.

Furthermore, in patients with serious illnesses, urine volume can be measured and recorded without the intervention of a nurse or the like by directly connecting the bladder to a beaker. Furthermore, if necessary, a hydrometer, analyzer, etc. may be connected to enable direct urine testing, or a drain may be provided at the bottom of the beaker to allow for easy drainage after measurement. can.

In this embodiment, an ultrasonic liquid meter is used to measure urine, but the present invention is not limited to this and can be applied to any liquid meter that accurately measures the volume of liquid, such as measuring rainfall. .

[Effects of the invention] The present invention uses burst-shaped ultrasonic waves with a high frequency of 250KHz or higher, and the mounting plate on which the transmitter and receiver are attached can be adjusted horizontally with respect to the liquid being measured, thereby reducing the Measurement liquid can be measured accurately.

In addition to separating the transmitter and receiver, the output of the transmitter is muted for a certain period of time to prevent ultrasonic waves from directly jumping into the receiver, resulting in a more accurate measuring instrument. In addition to the above, when measuring urine, for example, it is possible to accurately measure up to 1 c.c., which has the effect of being useful for tests such as creatinine clearance.

[Brief explanation of the drawing]

Figure 1 is a diagram explaining the principle of the ultrasonic liquid meter of the present invention.
Fig. 2 is a transmission waveform diagram of the ultrasonic wave, Fig. 3 is a reception waveform diagram, Fig. 4 is a block diagram, Fig. 5 is a flowchart, and Fig. 6 is a urine flow diagram of the ultrasonic liquid meter of the present invention. It is a block diagram of the apparatus used for measurement. 21... Liquid meter body, 21a... Mounting part, 22
... Container, 23 ... Transmitter, 24 ... Receiver, 2
5...Mounting plate, 26...Adjustment screw, 27...Temperature sensor.

Claims (1)

[Scope of utility model registration request] A liquid meter main body having a container containing a liquid to be measured, a container mounting part for attaching and detaching the container, and a liquid meter body provided on the liquid meter main body and directed toward the liquid to be measured in the container.
A transmitter that transmits burst-shaped ultrasonic waves of 250 KHz or more and a receiver that receives ultrasonic waves reflected from the liquid to be measured, and the transmitter and receiver are held flush and horizontal to the liquid to be measured in the container. A mounting plate is attached to the liquid level meter body so that the mounting angle can be freely adjusted using an adjustment screw, and a mounting plate is attached to the output of the transmitter for a certain period of time to prevent ultrasonic waves from directly jumping into the receiver from the transmitter. a time measuring means for measuring the time from transmission to reception of the ultrasonic wave based on the output from the transmitter, and the transceiver and the measured liquid. An ultrasonic liquid meter comprising: a temperature sensor that measures the temperature of the atmosphere between the liquid and the liquid and corrects the time from transmission to reception of the ultrasonic waves.