JPH08320248A - Method of detecting passage of liquid in container such as bottle, and passage detector - Google Patents

Abstract

PURPOSE: To detect the passage of transported liquid in a wide range with simple operation without being influenced by the shape and material of a container by detecting and comparing the quantity of light reflection in a place with liquid and in a place without liquid in the container. CONSTITUTION: A sensor unit 1 is disposed at the center of a strip type band plate 4 with spring elasticity, and a band 5 is fitted to both ends of the band plate 4. The band 5 is tightened to fit the sensor unit 1 to a container 2. The sensor unit 1 with two light reflection sensors built in vertically is thereby fixed to the container 2. The output of two vertical light reflection sensors is amplified by an AC differential amplifier. When there is the predetermined quantity of liquid or more in the container 2 and two light reflection sensors are both in the positions where liquid exists, the output of the AC differential amplifier is zero. When the liquid in the container is reduced and the liquid level is between the vertical light reflection sensors, the output of the upper light reflection sensor is larger than that of the lower light reflection sensor, and the output of the differential amplifier corresponding to the difference is displayed.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container such as a bottle for detecting the remaining amount of infusion solution in a bottle used during surgery in a hospital and effectively detecting the remaining amount of liquid in the container in various experiments. TECHNICAL FIELD The present invention relates to a method of detecting passage of a liquid in the inside and a passage detector thereof. Generally, a bottled infusion is used during surgery in a hospital. This infusion should be avoided during surgery. The use of the transfusion residual amount alarm device is effective as a means for issuing an alarm when the transfusion residual amount in the transfusion bottle becomes small at the time of surgery and reliably replacing the transfusion bottle. By using the remaining amount alarm device, you can prevent the infusion from running out,
The attention of the surgical personnel can be focused on the patient's surgery. The present invention applies the liquid level passage detector to a remaining amount alarm device,
Aiming for a wide range of use and ease of use, the material of the bottle is synthetic resin such as glass and polyethylene, and it may be translucent or transparent as long as it reflects light on the surface of the container. Easy to use and easy to set in a bottle regardless of its shape such as circular or elliptical in cross section, without changing the shape of the sensor according to these shapes and materials, and without the need for sensitivity adjustment. It can be widely used in various industrial fields. In the present invention, since a transparent liquid can be used, as a matter of course, it is possible to use an opaque liquid in principle and can be used for a wide range of liquids. It is clear that it is very convenient to use that it is possible to check the remaining amount position at a glance because the position where the remaining amount is detected is determined by the mounting position of the sensor.

[0002]

2. Description of the Related Art In the weighing system used as a remaining amount alarm device currently used, it is necessary to preset the weight of a bottle having a constant amount of infusion solution. This setting differs depending on the size of the bottle and is set for each bottle, so that the bottle is limited, and the setting operation becomes complicated, and knowledge of the operation of the device is required. Also, if you forget that the bottle has changed, the setting will be incorrect, which will cause trouble because the remaining amount is not detected normally. In the method of detecting the light transmission amount, the difference in the light transmission amount with and without the transparent liquid is small, and it is necessary to adjust the sensitivity of the sensor in a preliminary test.
In addition, there is a light receiving portion and a light emitting portion for light, and it is necessary to set them on the opposite surfaces of the bottle, and if the shape of the bottle is different, a fitting fitting for it is required and it is not easy to use.

[0003]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and has a simple operation and a wide range of containers such as bottles and infusion solutions which are not affected by the shape and material of containers such as bottles. (EN) It is possible to provide a method for detecting passage of a liquid in a container such as a bottle and a passage detector which can detect the passage of the liquid by covering the liquid and effectively improve the usability of the remaining amount alarm device. .

[0004]

A detector must be attached to the surface of a container such as a bottle because it is not affected by the shape of the container such as a bottle. The light reflection sensor is suitable for this condition,
The amount of light reflected by the light reflection sensor differs depending on the material of the container such as a bottle and the conditions such as semitransparent and transparent. In order to eliminate this, the above problem is solved by using two light reflection sensors that are vertically adjacent to each other and comparing a portion with liquid and a portion without liquid. The 2
The outputs of the two light reflection sensors can be compared by amplifying the two light reflection sensors with a differential amplifier in order to obtain a compared signal of the output signals of the light reflection sensors.
This method detects the remaining amount of liquid by detecting the remaining amount of liquid by passing the first of the two light reflection sensors, so the detection of passage is transient, so prepare a circuit to memorize the passage. If this is done, the alarm can be issued continuously.

2 if the container such as a bottle is full of liquid
If the output difference of each light reflection sensor is taken, the output difference becomes zero regardless of the material of the container such as a bottle, transparent or translucent.
Here, if the liquid level in the container such as a bottle falls and there is a liquid level between the two light reflection type sensors, the liquid does not exist in the upper light reflection sensor, and the liquid does not exist in the lower light reflection sensor. Since it exists, the amount of light reflection is different between the upper and lower parts, and an output difference appears between the outputs of the light reflection sensors. That is, when the liquid level reaches this position, an output difference appears, and an alarm is sounded by this output difference to give an alarm to a member who is performing a work such as surgery.

The passage detector is provided with two light reflection sensors vertically adjacent to each other, a differential amplifier for amplifying the difference between signals, a voltage comparison circuit for judging the magnitude of the output difference, a buzzer,
It is configured by incorporating all the batteries or by housing some of them in a separate case. The attachment of the unit containing the two light reflection sensors to the container such as a bottle is performed in order to cope with a wide range of container shapes such as bottles. A plate is provided and velvet fasteners are attached to both ends of the plate. A thin rubber is attached to the surface of the container such as a bottle that is in contact with the container to prevent the unit containing the two light reflection sensors from slipping and to keep the narrow space between the light reflection sensor and the container surface stable. Although the velvet fastener is easy to connect and is used, it is not limited to this, and any band may be used as long as it is simple to connect and has little friction on the side surface of a container such as a bottle.

A unit containing two light-reflective type sensors vertically is wound around a container such as a bottle with left and right velvet fasteners, and is fixed to the side surface of the container such as the bottle by connecting them. The strips protruding to the left and right serve as leaf springs. As a result, the unit containing the two light reflection sensors in the vertical direction is firmly fixed to the container such as a bottle.
As described above, it becomes possible to detect a constant remaining amount of liquid in a wide range of containers such as bottles.

[0008]

It is generally known that the amount of light reflected by a container such as a transparent or semi-transparent bottle that reflects light varies depending on the presence or absence of a transparent liquid. The amount of light applied to the surface of a container such as a bottle is reflected by the surface of a container such as a bottle, and this amount is referred to as a first reflection amount. Further, the light passes through the plate thickness of the container such as the bottle, and the light passes through the inner wall of the container such as the bottle into the inside of the container such as the bottle. Here, the reflection of light reflected and returning to the outside of a container such as a bottle is referred to as a second reflection amount. The amount of light returning to the outside of a container such as a bottle is considered to be the sum of the two. If the inside of a container such as a bottle is filled with a liquid, the inner wall of the container such as a bottle and the liquid have a close refractive index, so it is considered that no boundary surface exists on the light transmission route, and reflection does not occur, and the light The entire amount goes out into the container such as a bottle, and there is no second reflection amount. In reality, since the refractive indices are not exactly the same, the second reflection amount does not become zero, but they are almost the same, so that the difference between the second reflection amount with and without the liquid appears. The state of the reflection is shown in FIG.

The amount of light reflected differs depending on the presence or absence of a transparent liquid,
The presence or absence of a transparent liquid or the like can be detected by the change in the reflection amount, but if the material of the container such as a bottle changes, the difference is added to the change amount and cannot be used without adjustment. It is necessary to be able to digitally determine the output of a light reflection sensor having a light emitting portion and a light receiving portion, regardless of the material.

In order to solve this, in the present invention, it is considered that there is no sensor signal output when there is a liquid and there is a sensor signal output when the liquid surface passes, and digitization is considered. A small light reflection sensor with a light emitting part and a light receiving part integrated is readily available as a semiconductor device, so two digital light sensors can be used in the vertical direction along the movement axis of the liquid surface for the digitization. A reflection sensor was placed. It is shown in FIG. If a container such as a bottle is filled with a liquid, the two light reflection sensors installed in the vertical direction are placed under the same condition, so that the individual outputs are the same. Here, the outputs from the two light reflection sensors can be made zero by passing through a differential amplifier circuit to obtain the difference between the output of the upper light reflection sensor and the output of the lower light reflection sensor. Since the two light reflection sensors are placed under the same conditions, they have nothing to do with the material of the container such as a bottle and the transparency or translucency.

Here, when the liquid level in the container such as a bottle is lowered and there is a liquid level between the two light reflection sensors, when there is no liquid in the upper light reflection sensor, the reflection is performed as described above. The amount of light emitted is larger than that of the lower light reflection sensor, and the signal output of the upper light reflection sensor is larger than that of the lower light reflection sensor. As described above, the difference between the two output signals is taken, so that a difference signal appears. The size of the difference signal here is whether the container such as a bottle is glass,
Although it differs depending on whether it is a synthetic resin such as polyethylene or transparent or semi-transparent, the ratio between the minimum and maximum cases is about 1: 3 experimentally, and the output signals of the two light reflection sensors are properly amplified. It can be replaced with the presence of the differential signal by comparing with the reference voltage after amplification using the differential amplifier provided.

As described above, when the liquid level passes, there is a signal, so if it is "1", the liquid level is on the upper side, and since there is no signal before passing, it can be digitized as "0". In the process of digitization, as described above, the difference in the material of the container such as the bottle, the transparency, and the translucency is eliminated, and the original purpose is achieved.

[0013]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 3 shows an example in which the sensor unit 1 for passing a liquid surface according to the present invention is attached to a container 2 such as a bottle to constitute a remaining amount alarm device 3. The sensor unit 1 is arranged in the center of a strip-shaped strip plate 4 having spring elasticity, and bands 5 are attached to both ends of the strip-shaped strip plate 4. By tightening the band 5 and attaching the sensor unit 1 to the container 2 such as a bottle, the strip plate 4 functions as a spring, and the sensor unit 1 having the light reflection sensors 6 and 6 housed vertically does not slip and The unit 1 is fixed to a container 2 such as a bottle in a vertically even position.

When viewed from the surface of the sensor unit 1 which is in contact with the container 2 such as a bottle, two light reflection sensors 6 are vertically arranged on the center as shown in FIG. Container 2 such as a bottle in the center
In order to keep the contact with Stable, a rectangular rubber sheet 7 having a width corresponding to the width of the strip plate 4 in which the light reflection sensors 6 are cut is stretched. The thickness of the rubber sheet 7 also plays a role of keeping the spatial distance between the light reflection sensor 6 and the surface of the container 2 such as a bottle constant.

The light reflection sensor 6 is a semiconductor element in which a light emitting diode as the light emitting portion 6a and a photodiode as the light receiving portion 6b, or a phototransistor are integrated. This element is an element used for detecting paper such as a printer and is widely used at a low cost. When this element is used to detect a blank sheet at intervals of about 1 mm, it is sufficient to turn on the LED by direct current lighting, but in the present invention, reflection by a transparent body or the like and glass thickness of a container such as a bottle are included. Since it is reflection, the amount of reflection is smaller than in the previous example. Further, as for the indoor light, since a container such as a bottle is transparent and the light enters the light reflection sensor 6 as ambient light, it is necessary to distinguish it from the LED light. In the present invention, an optical modulation method that is generally used under the condition that there is ambient light is adopted. The modulation method is a method of excluding ambient light by blinking an LED at a modulation frequency and amplifying and rectifying the signal of the blinking reflected light detected by the receiving unit.

The circuit configuration will be described with reference to the block diagram of FIG. Two light reflection sensors 6 are used, one on the upper side and one on the lower side. The LED of the sensor is blinked by a switching transistor for modulation. The switching is performed by a rectangular wave made by an oscillator, and the frequency is about 1 KHz. Two
Since the LEDs, which are light sources, are switched at the same time, the reflected light is detected by the phototransistor at the same frequency as the transmitter. A resistor and a potentiometer are connected to the phototransistor. This resistor serves to convert a current proportional to the reflected light entering the phototransistor into a voltage. Here, the role of the potentiometer is to adjust the variation in the characteristics of the two light reflection sensors, and to adjust the outputs of both light reflection sensors to be equal when both the light reflection sensors are at the liquid position.

Two light reflection sensors 6 installed vertically
The output of is amplified by the AC differential amplifier 8. The AC differential amplifier 8 amplifies the signal of the reflected light that has been switched and becomes AC, and amplifies the difference between the output signals of the upper and lower two light reflection sensors. AC differential amplifier output = Vup−Vdown where Vup is the output of the upper optical reflection sensor and Vdown is the output of the lower optical reflection sensor. The output of the AC differential amplifier is zero if both light reflection sensors are in the liquid position. This is the case when the amount of the liquid exceeds the specified amount. When the liquid in the container such as a bottle is reduced and the liquid level is between the upper and lower light reflection sensors 6, 6, the upper light reflection sensor 6
At the position of, there is no liquid and the amount of light reflected is greater than at the lower side. ΔV appears in the output of the AC differential amplifier.

Since the output of the differential AC amplifier 8 also contains disturbance noise, it is converted into a signal related to the liquid level through synchronous rectification and a low pass filter. Synchronous rectification separates and extracts only the frequency component that blinks the LED, and the low-pass filter plays a role of removing the LED blinking frequency component and noise. Therefore, a signal related to the liquid level can be obtained by passing these components. . The graph of FIG. 6 shows the relationship between the smoothed signal and the liquid surface at point 1 (P1) in FIG. Further, a reference voltage is provided and compared with the liquid level signal. If the voltage is higher than the reference voltage, the liquid level is at the midpoint between the upper and lower light reflection sensors 6, 6. The output P2 of the comparator 9 is shown in the graph of FIG.

The flip-flop is set at the rising edge of the passing signal, and the passing is recorded. A remaining amount alarm can be configured by sounding a buzzer at the output of the flip-flop.

[0020]

As described above, the present invention has been completed by pursuing how to simply attach the sensor to a container such as a bottle and detecting the remaining amount of the container such as the bottle. . The simple operation and the ability to set the sensor regardless of the shape of the container such as a bottle will help spread the remaining amount alarm device. Further, the light reflection sensor is attached to the container by providing strip plates having spring elasticity on the left and right sides of a unit accommodating two light reflection sensors in the vertical direction and connecting velvet fasteners or the like on both sides of the strip plate easily. A band is provided, and the unit is set at a predetermined position on the container and wound around the container by using the band, and the two light reflection sensors housed in the unit are attached to the bottle by using spring elasticity of the band plate. Since it can be fixed to the surface equally, it can be reliably and stably attached to a container of any shape, and liquid passage can be detected reliably.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing the position of a light reflection sensor in a container such as a bottle and the amount of light reflected by a liquid.

FIG. 2 is a schematic explanatory view showing the behavior of reflected light on the surface of a container such as a bottle, and FIG. 1 (a) shows the case where a liquid is present;
(B) shows the case where there is no liquid.

FIG. 3 is a perspective view showing how the sensor is attached to a container such as a bottle.

FIG. 4 is a perspective view showing a unit in which two light reflection sensors are mounted vertically.

FIG. 5 is a block diagram of a remaining amount alarm device.

FIG. 6 is a graph showing liquid level signals obtained by two light reflection sensors.

FIG. 7 is a graph showing a liquid level passage signal extracted in comparison with a reference voltage.

[Explanation of symbols]

 1 Sensor Unit 2 Container 3 Remaining Volume Alarm 4 Band 5 Band 6 Optical Reflection Sensor 7 Rubber Sheet 8 AC Differential Amplifier 9 Comparator

Claims (6)

[Claims] 1. A method of detecting passage of a liquid in a container using a container capable of reflecting light, wherein the amount of light reflected by the container is the amount of light reflected at a portion where liquid is present and the portion where no liquid is present. The method for detecting passage of a liquid in a container such as a bottle is characterized by detecting the light reflection output signals as light reflection output signals and comparing the light reflection output signals to detect that the liquid surface has passed. 2. In the detection of passage of a liquid in the container using a container capable of reflecting light, the amount of light reflected by the container is such that the amount of light reflected at a portion with liquid and the amount of light at a portion without liquid. A light reflection sensor for detecting each reflection amount is installed at two locations in the vertical direction on the outer surface of the container, and means for comparing the light reflection sensor output signals from the two locations to detect passage of the liquid surface is provided. A passage detector for a liquid in a container such as a bottle. 3. The means for comparing the light reflection sensor output signals and detecting the passage of the liquid surface includes a memory circuit for continuously issuing an alarm after the reflected light amount difference signal appears in the comparator. A liquid passage detector for a liquid such as a bottle according to claim 2, further comprising a liquid remaining amount alarm device provided. 4. To measure the amount of light reflected from a container such as a bottle, light reflection sensors are installed at two vertical positions maintaining a space extremely narrower than the surface of the container, and the light reflection sensors at both of these two positions are liquid. The passage detector for liquid in a container such as a bottle according to claim 2 or 3, further comprising a comparator that uses the amount of reflected light when there is a reference value as a reference value. 5. A light reflection sensor is installed at two vertical positions maintaining a space extremely narrower than the container surface in order to measure the amount of light reflected from the container such as a bottle, and one of the two light reflection sensors is provided at one of the two positions. Is a liquid, and when there is a reflected light amount difference signal when there is no liquid in the other, a detector that detects that the liquid surface is passing, assuming that there is a liquid surface between the two light reflection sensors in the vertical direction The passage detector for a liquid in a container such as a bottle according to claim 2, 3 or 4, further comprising: 6. A strip plate having spring elasticity is provided on the left and right of a unit accommodating two light reflection sensors in the vertical direction, and bands for easy connection such as a velvet fastener are provided on both sides of the strip plate. Was set at a predetermined position in the container and wound around the container using the band, and the two light reflection sensors housed in the unit were equally fixed to the surface of the bottle by using the elasticity of the strip plate. A passage detector for a liquid in a container such as a bottle.