CN209400046U - A liquid level detection device for a murphy pot - Google Patents

Abstract

The utility model provides a liquid level detection device for a Murphy pot, which comprises a Murphy pot, two sensors, a conversion circuit and a comparison circuit; the sensor is composed of an infrared emitter, an infrared absorber and two light guide tubes; Infrared emitters and infrared absorbers are respectively placed in the light guide tubes on both sides of the same horizontal plane of the Murphy pot; sensor one is arranged on the upper part of the Murphy pot, and sensor two is arranged on the Murphy pot The lower part of the sensor is equipped with a conversion circuit at the input end and output end of the sensor respectively. Only when the output current (output voltage) of sensor one > the output current (voltage) of sensor two, the utility model does not need to report to the police, and all other situations need to report to the police.

Description

A liquid level detection device for a murphy pot

technical field

The utility model designs a liquid level detection device, in particular to a liquid level detection device for a murphy pot.

Background technique

Intravenous infusion is one of the commonly used disease treatment methods. At present, the commonly used infusion tube is basically made of transparent plastic. The intravenous infusion line itself does not have the monitoring and alarm function. Timely processing to avoid blood return in the infusion line is a very heavy workload for medical staff, and it is also a burden for patients and their families, especially for patients, which affects their rest. Sometimes due to the carelessness or fatigue of patients and their family members, or the busy nurses who fail to make inspections in time, they cannot find the end of the liquid infusion in time, resulting in blood returning in the infusion tube or air entering the blood vessel, resulting in adverse consequences. Therefore, an additional infusion alarm is needed, and when the infusion is about to end, the infusion alarm generates an alarm signal to remind the patient and family members or medical staff.

The main types of existing liquid level detection devices include weight measurement, capacitance sensing, photoelectric sensing and other different types. Some types have complex structure, high cost, many steps to use, and cumbersome operation process; some types are designed and innovated for the infusion bag itself, which cannot be applied to all types of infusion bags, and the practicability is not high. The sensor that triggers the alarm signal is in the Sensing is carried out in the sensing area, but the sensor must be directly inserted into the infusion bottle for use, which may contaminate the liquid medicine.

Therefore, how to design a medical infusion alarm or a medical infusion alarm system with easy operation and high accuracy has become a problem to be solved at present.

Chinese Patent Application Publication No. CN 102284105A, the title of the invention is an infusion alarm device, which discloses an infusion alarm system centered on liquid level detection and a single-chip microcomputer, including a power module, a photoelectric sensor, a comparator, a single-chip microcomputer, an LED Lamp, sound alarm device and actuator; Among them, the liquid in the infusion tube is detected by a photoelectric sensor (photoelectric interrupter), and the infusion alarm system is controlled by a single-chip microcomputer; the photoelectric sensor is a photoelectric interrupter, which is used to detect the liquid in the infusion tube The comparator is a voltage comparator; when there is liquid in the infusion tube, the phototransistor of the photoelectric sensor receives stronger infrared light emitted by the infrared diode, and the current flowing through the phototransistor circuit is relatively large, so the negative voltage of the voltage comparator The voltage decreases, the output is high level, the alarm does not take any action, and the infusion continues; when the infusion is close to the end, that is, when the infusion tube has no liquid, the photosensitive triode of the photoelectric sensor receives the weak infrared light emitted by the infrared diode, The current flowing through the phototransistor circuit is small, and the current changes significantly, so the negative voltage of the voltage comparator increases, and the output is low. But what happened was that the Murphy pot was full of liquid, indicating that there was a failure in the infusion, and the medical staff also needed to be notified, but the infusion alarm device could not alarm.

Contents of the invention

Aiming at the above defects or improvement needs of the prior art, the utility model provides a detection device in three different states, that is, the murphy pot has no liquid, is half-filled, and is full of liquid.

The technical scheme of the utility model is:

A liquid level detection device for a Murphy pot, comprising a Murphy pot, two sensors, a conversion circuit and a comparison circuit; the sensor is composed of an infrared emitter, an infrared absorber and two light guide tubes; the infrared emitter, the infrared Absorbers are respectively placed in the light guide tubes on both sides of the same level as the Murphy pot;

Sensor one is set on the upper part of the Murphy pot, sensor two is set on the lower part of the Murphy pot,

The input end and the output end of the sensor are respectively provided with conversion circuits;

The conversion circuit is used to output the voltage Ve1 at the terminal e of the sensor 1 after the conversion circuit, and the sensor 2 outputs the voltage Ve2 at the terminal e after the conversion circuit;

The output voltage Vout of the output terminal of the comparison circuit=Ve2-Ve1;

When the output voltage or current of sensor 1 and sensor 2 is the same or similar, it means that there are two situations in the Murphy pot of the infusion tube: one is that there is air in the Murphy pot, which means that the infusion has been completed;

Another situation is that the Murphy pot is full of liquid, indicating that the infusion has failed;

When the output voltage or current of the first sensor and the second sensor is obviously different, there are two situations:

The first is that the output voltage or current of sensor one is significantly smaller than the output current of sensor two, indicating that the sensor is faulty;

The second situation is that the output voltage or current of sensor 1 is significantly greater than the output current of sensor 2, indicating that there is medicinal liquid in the Murphy pot and the Murphy pot is not full, which is a normal infusion state.

Further, the above-mentioned infrared emitter and infrared absorber are respectively an LED light-emitting diode D1 and a phototransistor D2.

Further, the output terminal and the output terminal of the above sensor are respectively provided with a conversion circuit, and the conversion circuit includes a parallel circuit of a power supply, an LED current limiting resistor R1, a resistor (R2) and a capacitor (C1).

Further, the above-mentioned liquid level detection device also includes an execution circuit,

When the output current (output voltage) of sensor 1 > the output current (voltage) of sensor 2, no alarm is required, at this time Vout > 0, the buzzer does not work;

When the output current (output voltage) of sensor one ≤ the output current (voltage) of sensor two, Vout ≤0, the buzzer starts to work.

Further, the above-mentioned execution circuit consists of two resistors and two triodes, the base b of the triode D5 is connected to one end of the resistor R7, the collector C of D5 is connected to the base b of D6, the emitter e of D5 is grounded, and the collector of D6 c is connected to the power supply VCC, the emitter e of D6 is connected to one end of the buzzer, and the two ends of the resistor R8 are respectively connected to the power supply VCC and the collector C of D5.

Generally speaking, compared with the prior art, the above technical solutions conceived by the utility model are as follows: the function of the sensor is to measure whether liquid is contained in the light propagation path; the attenuation rate of light propagating in water is greater than The attenuation rate of light propagating in the air, when the light is infrared, the contrast (or distinction) of this attenuation effect is more obvious.

When the output current of sensor 1 and sensor 2 is the same or similar, it means that there are two situations in the Murphy pot of the infusion tube. One is that there is air in the Murphy pot, which means that the infusion has been completed and an alarm signal needs to be output to notify the medical staff. Another situation is that all the liquid in the Murphy pot indicates that the infusion has failed, and the medical staff also need to be notified.

When the output currents of sensor one and sensor two are significantly different, there are two situations. The first is that the output current of sensor 1 is significantly smaller than the output current of sensor 2, which means that the sensor is faulty and needs to output an alarm signal for maintenance; There is liquid medicine in the Murphy pot, and the Murphy pot is not full, which is a normal infusion state.

To sum up, only when the output current (output voltage) of sensor 1 > the output current (voltage) of sensor 2, no alarm is required, and the alarm is required in other cases.

Description of drawings

Fig. 1 is the schematic diagram of the liquid level detecting device of the Murphy pot of the present utility model;

Fig. 2 is the schematic diagram of the sensor of the liquid level detection device of the Murphy pot of the present invention;

Fig. 3 is a schematic diagram of a conversion circuit of the present invention;

Fig. 4 is the comparison circuit schematic diagram of the present utility model;

Fig. 5 is a schematic diagram of an alarm circuit of the present utility model;

Fig. 6 is a schematic diagram of the alarm process of the liquid level detection device of the Murphy pot of the present invention;

7 is an overall schematic diagram of the liquid level detection device of the Murphy pot of the present invention;

1-Murphy pot; 2-sensor; 3-conversion circuit;

21-LED light-emitting diode D1; 22-photosensitive transistor D2; 23-light guide tube;

In Figure 1, the short arrow indicates the direction of infrared rays; the long arrow of the Murphy pot indicates the direction of infrared rays in the Murphy pot.

Detailed ways

In order to make the purpose, technical solution and advantages of the utility model clearer, the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described here are only used to explain the utility model, and are not intended to limit the utility model. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not constitute conflicts with each other.

Referring to Figure 1 and Figure 2, a liquid level detection device for a Murphy pot consists of a Murphy pot 1 and two sensors 2; (Sensor 2) is placed at the lower part of the Murphy pot 1.

The structure of sensor one and sensor two is shown in Figure 1, and each pair of sensors includes an LED light-emitting diode D1, a photosensitive transistor D2, and two light guide tubes 23; the light guide tube 23 is an opaque tubular structure, such as an opaque plastic tube and other materials.

The structure of the phototransistor is similar to that of the ordinary triode; the difference is that the phototransistor must have a light-sensitive PN junction as the photosensitive surface, and the collector junction is generally used as the light-receiving junction. Therefore, the phototransistor is essentially a kind of An ordinary triode with a photodiode connected between the base and collector. The phototransistor is the same as the ordinary semiconductor triode, it is a semiconductor tube with NPN or PNP structure made by semiconductor manufacturing process. It is similar in structure to a semiconductor triode, and its lead-out electrodes usually have only two or three. In order to meet the requirements of photoelectric conversion, the area of its base area is made larger, and the area of the emission area is made smaller, and the incident light is mainly absorbed by the base area. Like photodiodes, the chip of the tube is housed in a metal casing with a glass lens. When light is irradiated, the light is concentrated on the chip through the lens. When the PN junction with photosensitive characteristics is irradiated by light, a photocurrent is formed, and the resulting photogenerated current enters the emitter from the base, so that a signal current amplified by β times is obtained in the collector circuit.

The LED light-emitting diode is placed in the light guide tube. The function of the light guide tube is to gather the light emitted by the LED light-emitting diode; the photosensitive transistor D2 receives the light from D1 and generates an output current corresponding to the light intensity. The function of the light guide tube is Block the light from other directions, so that D2 only accepts the light from D1, thereby reducing the interference of ambient light.

The role of the sensor is to measure whether liquid is contained in the path of light propagation. The attenuation rate of light propagating in water is greater than the attenuation rate of light propagating in air, and when the light is infrared, the contrast (or distinction) of this attenuation effect is more obvious.

When the output current of sensor 1 and sensor 2 is the same or similar, it means that there are two situations in the Murphy pot of the infusion tube. One is that there is air in the Murphy pot, which means that the infusion has been completed and an alarm signal needs to be output to notify the medical staff. Another situation is that all the liquid in the Murphy pot indicates that the infusion has failed, and the medical staff also need to be notified.

When the output currents of sensor one and sensor two are significantly different, there are two situations. The first one is that the output current of sensor one is obviously smaller than the output current of sensor two, indicating that the sensor is faulty and needs to output an alarm signal for maintenance; the second case is that the output current of sensor one is obviously greater than the output current of sensor two, indicating that the ink There is liquid medicine in the Murphy pot, and the Murphy pot is not full. This situation is a normal infusion state, and no alarm signal needs to be output.

To sum up, only when the output current (output voltage) of sensor 1 > the output current (voltage) of sensor 2, no alarm is required, and the alarm is required in other cases.

See Figure 3, conversion circuit:

Since infusion is a slowly changing process, and the output voltage and current of the sensor is a transient value, it may be falsely alarmed by external interference. In order to reduce and eliminate false alarms, a conversion circuit is needed to convert the transient value of the sensor is a quasi-stable value.

A simple conversion circuit includes a power supply, LED current-limiting resistor R1, and a parallel circuit of a resistor (R2) and a capacitor (C1), as shown in Figure 3. The capacitance value of the capacitor is generally relatively large, such as tens of microfarads, and the specific value is determined through experiments. The output of the conversion circuit is terminal e. Then the sensor 1 outputs the voltage Ve1 at the terminal e after passing through the converting circuit, and the sensor 2 outputs the voltage Ve2 at the terminal e after passing through the converting circuit.

See Figure 4, comparison circuit:

A subtraction op amp circuit is used, as shown in the figure below; in the figure, Ve1 is the output voltage of the terminal, and is the output voltage of the terminal. As shown in Figure 4, the four resistors are equal, that is, R3=R4=R5=R6, then the output voltage Vout of the output terminal f of the comparison circuit=Ve2-Ve1.

See Figure 5, the execution circuit:

The executive circuit can take various forms, and its main purpose is to send out various signals, such as lights and sounds, to remind patients and their families, or medical staff.

In Figure 5, the executive circuit of the conversion circuit consists of two resistors and two triodes, the base b of the triode D5 is connected to one end of the resistor R7, the collector C of D5 is connected to the base b of D6, the emitter e of D5 is grounded, and the The collector c is connected to the power supply VCC, the emitter e of D6 is connected to one end of the buzzer, and the two ends of the resistor R8 are respectively connected to the power supply VCC and the collector C of D5.

Resistor R7 limits the base current of D5 within the allowable range to reduce power consumption, and resistor R8 limits the triode current during the conduction period of D5 within the allowable range to reduce power consumption.

When the output current (output voltage) of sensor 1 > the output current (voltage) of sensor 2, no alarm is required. At this time, Vout > 0, transistor D5 is turned on, the base voltage of transistor D6 is zero, D6 is disconnected, and the buzzer buzzer does not work;

When the output current (output voltage) of sensor 1 <= the output current (voltage) of sensor 2, Vout <= 0, D5 is disconnected, D6 is turned on, and the buzzer starts to work to realize the purpose of alarm.

Supplementary Note:

VCC in all circuits is the same power supply; ground in all circuits is the same ground.

See Figure 6, Figure 7, flow chart and overall schematic diagram:

The overall design of the system is shown below. Including sensor, conversion circuit, comparison circuit, execution circuit and other functional modules.

Sensor 1 and sensor 2 measure different positions and output current; the output current of the sensor is converted into the positive voltage or zero voltage of the logic circuit through the conversion circuit; the positive voltage or zero voltage output by the conversion circuit is input into the comparison circuit, and the logic circuit of the comparison circuit After calculating and outputting the control model, the control execution circuit completes the corresponding action.

Claims (5)

1. a kind of liquid level detection device of the luxuriant and rich with fragrance pot of ink, including the luxuriant and rich with fragrance pot of an ink, two sensors, conversion circuit and comparison circuit； The sensor is made of a RF transmitter, infrared absorber and two light pipes；It is the RF transmitter, infrared Absorber is respectively placed in the light pipe of the two sides on ink luxuriant and rich with fragrance pot same level face；

It is characterized in that, sensor one is set to the top of the luxuriant and rich with fragrance pot of the ink, sensor two is set to the lower part of the luxuriant and rich with fragrance pot of the ink,

The input terminal and output end of the sensor are respectively equipped with conversion circuit；

The conversion circuit be used for sensor after conversion circuit in endpoint e output voltage Ve1, then sensor two is converted In endpoint e output voltage Ve2 after circuit；

Output voltage Vout=Ve2-Ve1 of the output end of the comparison circuit；

When the sensor one is with two output voltage of sensor or same or similar electric current, illustrate that the luxuriant and rich with fragrance pot of the ink of perfusion tube exists Two kinds of situations: one is being all air in black luxuriant and rich with fragrance pot, this illustrates that infusion has been completed；

Another situation is that being entirely liquid in ink phenanthrene pot, illustrate that failure occurs in infusion；

When the sensor one and two output voltage of sensor or significantly different electric current, there are two kinds of situations:

The first output voltage for being sensor one or electric current are significantly less than the output electric current of sensor two, illustrate that sensor occurs Failure；

Second situation is the output voltage of sensor one or electric current is significantly greater than the output electric current of sensor two, illustrates black luxuriant and rich with fragrance pot In there are medical fluids, and that full of the luxuriant and rich with fragrance pot of ink, such situation does not belong to normal infusion state.

2. liquid level detection device as described in claim 1, which is characterized in that the RF transmitter, infrared absorber point It Wei not an a LED light emitting diode D1 and phototriode D2.

3. liquid level detection device as described in claim 1, which is characterized in that the conversion circuit includes power supply, LED current limliting electricity Hinder R1 and resistance R2 and capacitor C1 parallel circuit.

4. liquid level detection device as described in claim 1, which is characterized in that the liquid level detection device further includes an execution Circuit,

When the output current or voltage of the output electric current of sensor one or output voltage > sensor two, do not need to alarm, at this time Vout > 0, buzzer do not work；

When the output current or voltage of the output electric current of sensor one or output voltage≤sensor two, Vout≤0, buzzing Device is started to work.

5. liquid level detection device as claimed in claim 4, which is characterized in that the execution circuit is two resistance and two three Pole pipe, one end of the base stage b connection resistance R7 of triode D5, the transmitting of the base stage b, D5 of the collector C connection D6 of D5 Pole e ground connection, one end of the emitter e connection buzzer of collector c connection the power supply VCC, D6 of D6, the both ends of resistance R8 It is separately connected the collector C of the power supply VCC and D5.