Automatic intravenous fluid injector using pressure sensor

Abstract

The present invention relates to an automatic intravenous fluid injector comprising: an intravenous fluid bag; a connection tube forming a passage through which an intravenous fluid is injected into a patient: an intravenous fluid tank in which the intravenous fluid bag is stored and which has an externally installed gas tube that can permit or block the passage of gas; a drive device for adjusting the cross-sectional area of the connection tube; a pressure sensor for measuring the internal pressure of the intravenous fluid tank; and a control device for calculating the injection amount of the intravenous fluid by measuring the gas pressure in the intravenous fluid tank by using the fact that, when the gas injected into the intravenous fluid tank through the gas tube presses the intravenous fluid bag so that the intravenous fluid is injected through the connection tube, the volume of the injected intravenous fluid corresponds to the volume change of the gas in the intravenous fluid tank, wherein the control device calculates the injection speed on the basis of sensing data of the pressure sensor and controls the drive device so that the injection speed corresponds to a predetermined speed.

Description

Automatic Infusion Pump Using a Pressure Sensor

[0001] The present invention relates to an automatic infusion pump, and more particularly, to an automatic infusion pump implemented using a pressure sensor that can be easily moved portably and can stably inject a liquid medicine regardless of the height change of the liquid medicine bag.

[0002] The administration of general liquid medicines depends on the drop height. For this purpose, a liquid medicine bag is placed at a position higher than the patient's heart using a hanger or the like, and the liquid medicine in the liquid medicine bag is administered to the patient by the height difference. In this case, it is known that the vertical height between the liquid medicine bag and the patient's heart should be maintained at an average of about 80 cm so that the liquid medicine can be stably injected without the risk of blood backflow.

[0003] Therefore, when injecting a liquid medicine depending on gravity like this, there are many inconveniences. The patient or caregiver must always strive to maintain the height of the liquid medicine bag at an appropriate height, and when moving, it is necessary to use a hanger or the like or the caregiver must accompany and hold the liquid medicine bag to maintain its height at an appropriate height, which causes difficulties.

[0004] Therefore, there is always no concern about blood backflow regardless of the position between the liquid medicine bag and the patient's heart in relation to the injection of the liquid medicine bag, and the injection speed of the liquid medicine is constant, so that the liquid medicine can be stably administered. Furthermore, there is a demand for an infusion pump that is easy to carry and allows the patient to move comfortably alone.

[0005] An object of the present invention is to provide an automatic infusion pump that always has no concern about blood backflow regardless of the position between the liquid medicine bag and the patient's heart, can automatically adjust the injection speed of the liquid medicine, stably administer the liquid medicine, and is easy to carry and allows the patient to move comfortably alone.

[0006] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the following description.

[0007] An automatic infusion device according to an embodiment of the present invention includes a liquid medicine bag filled with liquid medicine inside, a connection tube connected to the liquid medicine bag and configured to form a passage through which the liquid medicine inside the liquid medicine bag is injected into an external patient, a liquid medicine tank in which the liquid medicine bag is accommodated and an organ capable of blocking the entry and exit of gas is installed outside, a driving device configured to adjust the cross-sectional area of the connection tube, a pressure sensor installed in the organ or the liquid medicine tank and configured to measure the internal pressure of the liquid medicine tank, and after injecting and sealing gas into the liquid medicine tank through the organ, when the gas inside the injected liquid medicine tank presses the liquid medicine bag and injects the liquid medicine through the connection tube, a control device configured to measure the gas pressure inside the liquid medicine tank by using the fact that the volume change of the injected liquid medicine corresponds to the volume change of the gas inside the liquid medicine tank and calculate the injection amount of the liquid medicine. The control device is further configured to calculate the injection speed based on the sensing data of the pressure sensor and control the driving device so that the injection speed corresponds to a preset speed.

[0008] According to an embodiment, the liquid medicine tank may further include a housing forming the outer shape of the liquid medicine tank, an air pocket located inside the housing, connected to the organ, and expanding as a certain amount of gas flows in and adhering to the liquid medicine bag, and a fixing part detachably attached to the housing and configured to accommodate and fix the liquid medicine bag inside the housing.

[0009] According to an embodiment, the housing may have a volume change according to the change in the internal pressure below a certain level.

[0010] According to an embodiment, the air pocket may be composed of an elastic body in the form of a balloon or may be composed of a space between one surface of the housing and the elastic body.

[0011] According to an embodiment, the fixing part may include a hole through which the liquid outflow part of the liquid bag is fixed and the liquid outflow part is exposed to the outside of the liquid tank so as to be connected to the connection pipe.

[0012] According to an embodiment, the driving device may further include a connection pipe adjusting part configured to compress the connection pipe to adjust the cross-sectional area; a motor for driving the connection pipe adjusting part; and an encoder configured to measure the rotation of the motor and generate position information of the connection pipe adjusting part.

[0013] According to an embodiment, when the control device determines that the position of the connection pipe adjusting part is different from the expected position based on the position information, it may determine that an abnormal situation has occurred and generate a warning signal.

[0014] According to an embodiment, when a certain amount of gas flows into the liquid tank through the engine, the control device may confirm entry into a specific section where the inflow rate of the gas and the internal pressure are proportional based on the sensing data.

[0015] According to an embodiment, when entry into the specific section is confirmed, it may further include a calibrator that opens the opening / closing device and allows additional gas to flow into the liquid tank.

[0016] According to an embodiment, the calibrator is a volume type calibrator, and the control device uses the volume type calibrator to inject a fixed amount of the additional gas, and then calculates the volume of the internal gas of the aqueous solution tank by using the change in gas pressure in the aqueous solution tank before and after the additional gas flows in, so as to calculate the amount of aqueous solution injected per unit time corresponding to the injection rate.

[0017] According to an embodiment, the calibrator is a pressure type calibrator, and the control device uses the pressure type calibrator to calculate the volume of the internal gas of the aqueous solution tank by using the gas pressure in the aqueous solution tank before and after the additional gas flows in, the gas pressure of the pressure type calibrator before the additional gas flows in, and the volume of the pressure type calibrator, so as to calculate the amount of aqueous solution injected per unit time corresponding to the injection rate.

[0018] According to an embodiment, the control device can calculate the amount of aqueous solution injected per unit time by considering a correction coefficient for the change in volume of the internal gas according to pressure.

[0019] Other specific details of the present invention are included in the detailed description and the drawings.

[0020] The automatic aqueous solution injector using a pressure sensor according to an embodiment of the present invention can adjust the injection of the aqueous solution and measure the injection rate without using gravity, and the patient can easily carry it without using a hanger (aqueous solution hanging rack). In addition, the strength of the aqueous solution tank does not need to be strong, it can be made of PC (polycarbonate), and the weights of the pressure sensor and the control unit are also small, so the product can be lightweight.

[0021] In addition, the automatic infusion device using the pressure sensor according to the embodiment of the present invention can predict the pressure of the liquid medicine tank, encoder position information, liquid medicine infusion amount, etc., and can predict the expected time of completion of liquid medicine infusion, detachment of the liquid medicine drip and the liquid medicine connection tube, blockage of the liquid medicine infusion passage, and extravasation of the liquid medicine.

[0022] The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

[0023] FIG. 1 is a block diagram of an automatic infusion device using a pressure sensor according to an embodiment of the present invention.

[0024] FIG. 2 is a block diagram showing an example of the driving device of FIG. 1.

[0025] FIGS. 3 and 4 are block diagrams showing an example of the processor of FIG. 2.

[0026] FIG. 5 is a diagram showing a liquid medicine tank and a liquid medicine bag according to an embodiment of the present invention.

[0027] FIGS. 6 to 14 are flowcharts showing specific examples of FIG. 5.

[0028] FIG. 15 is a diagram for explaining a specific section in which the automatic infusion device according to an embodiment of the present invention operates.

[0029] FIG. 16 is a diagram showing a liquid medicine tank and a liquid medicine bag according to another embodiment of the present invention.

[0030] FIG.17 is a diagram showing a calibrator according to an embodiment of the present invention.

[0031] Hereinafter, embodiments of the present invention will be described clearly and in detail so that those of ordinary skill in the art of the present invention can easily implement the present invention. However, since the present invention can be implemented in various different forms within the scope described in the claims, the embodiments described below are merely illustrative regardless of the expression. That is, the present invention is not limited to the embodiments disclosed below and can be implemented in various different forms.

[0032] The terms used in this application are only used to describe specific embodiments and are not intended to limit the present invention. The singular expression includes the plural expression unless the context clearly indicates otherwise. In this application, terms such as "include" or "have" are intended to specify that there are features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and it should be understood that they do not preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof in advance.

[0033] Terms such as first, second, etc. may be used to describe various components, but the components should not be limited by these terms. These terms are only used for the purpose of distinguishing one component from another.

[0034] Similar to the components disclosed in this specification being capable of being executed as software programming or software elements, embodiments of the present invention include various algorithms implemented as combinations of data structures, processes, routines, or other programming constructs and can be implemented in programming or scripting languages such as C, C++, Java, assembler, etc. Functional aspects can be implemented as algorithms executed on one or more processors. In addition, the present embodiments can employ prior art for at least one of electronic environment setting, signal processing, and data processing. Terms such as "mechanism", "element", "means", "configuration" can be used broadly and are not limited to mechanical and physical configurations. The above terms can include the meaning of a series of software routines in association with a processor, etc.

[0035] In the present disclosure, methods implemented as software modules or algorithms can be stored on a computer-readable recording medium as computer-readable codes or program commands executable on a processor. Here, the computer-readable recording medium can include magnetic storage media (e.g., ROM (read-only memory), RAM (random-access memory), floppy disk, hard disk, etc.) and optical reading media (e.g., CD-ROM, DVD (Digital Versatile Disc)), etc. The computer-readable recording medium can be distributed and executed on computer systems connected by a network.

[0036] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings.

[0037]

[0038] Figure 1 is a block diagram of an automatic infusion device using a pressure sensor according to an embodiment of the present invention. The automatic infusion device (100) may include a liquid medicine tank (110), a liquid medicine bag (120), a liquid medicine connecting tube (130), a driving device (140), a control device (150), a pressure sensor (160), and an organ (170).

[0039] The automatic infusion device (100) may be configured to introduce a certain amount of gas into the liquid medicine tank (110) and seal it so that the introduced gas presses the liquid medicine bag (120). When the liquid medicine inside the liquid medicine bag (120) is injected into the patient, the volume of the gas in the liquid medicine tank (110) increases by the volume of the injected liquid medicine. At this time, the amount of gas does not change, and as the volume occupied by the gas increases, the gas pressure in the liquid medicine tank (110) changes, and it may be configured to calculate the infusion rate of the liquid medicine using this.

[0040] The liquid medicine tank (110) may have a structure in which the liquid medicine bag (120) is accommodated inside and is sealed so that there is no leakage of the gas introduced through the organ (170). The liquid medicine tank (110) may have no volume change or a volume change below a certain level due to a change in internal pressure. According to an embodiment, the liquid medicine tank (110) may be named a static container.

[0041] The liquid medicine bag (120) may be accommodated inside the liquid medicine tank (110) with the liquid medicine filled. The liquid medicine filled in the liquid medicine bag (120) may be injected into the patient through the liquid medicine connecting tube (130). One end of the liquid medicine connecting tube (130) is connected to the liquid medicine bag (120), and the other end of the connecting tube is connected to the liquid medicine cannula (135), so that the liquid medicine can be injected from the liquid medicine bag (120) into the patient. That is, the liquid medicine connecting tube (130) may form a passage through which the liquid medicine inside the liquid medicine bag (120) is injected into the patient. The liquid medicine bag (120) or the liquid medicine connecting tube (130) may be a commonly used product.

[0042] The liquid is injected into the patient through the liquid connection tube (130), and the injection rate of the liquid can be adjusted by the driving device (140). The driving device (140) is connected to the liquid connection tube (130) and can be configured to adjust the cross-sectional area of the liquid connection tube (130). For example, the driving device (140) can apply pressure to the liquid connection tube (130) to reduce the cross-sectional area of the liquid connection tube (130), or release the pressure applied to the liquid connection tube (130) to increase the cross-sectional area of the liquid connection tube (130).

[0043] The mechanism (170) can be configured to introduce gas into the liquid tank (110) or discharge gas from the liquid tank (110). In addition, a pressure sensor (160) can be installed in the mechanism (170) to measure the internal pressure caused by the gas introduced into the liquid tank (110).

[0044] According to an embodiment, the pressure sensor (160) can be installed in the mechanism (170) or the liquid tank (110). The pressure sensor (160) can measure the internal pressure of the liquid tank (110) to generate sensing data and provide the sensing data to the control device (150).

[0045] According to an embodiment, the automatic liquid injector (100) can further include a weight sensor. Using the weight sensor, the weight of the liquid tank (110) equipped with the liquid bag (120) can be measured, including the devices and components installed in the liquid bag (120) among the mechanism (170), the pressure sensor (160), the control device (150), and the driving device (140). The automatic liquid injector (100) can measure the liquid injection amount using a weight sensor that senses the decrease in weight following liquid injection in the liquid bag (120) together with the pressure sensor (160), and use this for adjusting the liquid injection amount.

[0046] According to an embodiment, a method for sealing the introduced gas of the liquid tank (110) provided with the liquid bag (120) includes a method of installing an air pocket in the liquid tank (110) (airbag type) and a method of hermetically fixing the liquid connection pipe (130) connected to the liquid outlet or the liquid outlet pipe of the liquid tank (110) after installing the liquid bag (120) (non airbag type).

[0047] According to an embodiment, a calibrator may be used to measure the volume of gas in the liquid tank (110). The calibrator may be divided into a volume type calibrator and a pressure type calibrator according to the measurement method.

[0048] According to an embodiment, a volume type calibrator is a device that injects gas of a predetermined volume into the liquid tank (110) through the pipe (170). For example, it may be in the form of a pump equipped with a flow meter or a gas tight syringe.

[0049] According to an embodiment, a pressure type calibrator is a container having a constant volume and capable of being shielded, in which a pressure sensor is installed to measure the internal pressure.

[0050] According to an embodiment, when the control device (150) introduces gas into the liquid tank (110) through the pipe (170), it can receive data on the gas inflow rate from the volume type calibrator and determine a specific section where there is no change in the volume of gas in the liquid tank according to the gas inflow. The specific section is a section where the gas inflow rate into the liquid tank (110) and the internal pressure of the liquid tank (110) are proportional, and it means a section where there is no change in the volume of gas in the liquid tank (110) according to the gas inflow.

[0051] And after entering a specific section, a quantitative gas is additionally introduced into the liquid tank (110) through a volumetric calibrator and sealed. The control device (150) can calculate the gas volume of the liquid tank (110) before liquid injection by using the amount of the additional gas and the pressure inside the liquid tank (110) before and after the additional injection of the gas. The gas volume of the liquid tank (110) before injection is used as a constant when calculating the subsequent liquid injection rate.

[0052] According to an embodiment, when injecting gas into the liquid tank (100) through a pressure calibrator, when the pressure of the liquid tank (100) expected to be in the specific section is reached, the pipe of the liquid tank (100) connected to the pressure calibrator is blocked. Then, when the internal air pressure of the pressure calibrator is higher than the internal air pressure of the liquid tank (110) and the pressure calibrator is filled with gas and the pipe of the liquid tank (100) is opened, the gas of the pressure calibrator flows into the liquid tank (110), and the air pressures of the pressure calibrator and the liquid tank (110) become balanced. Then, the control device (150) can calculate the gas volume of the liquid tank (110) by using the volume of the pressure calibrator, the pressure of the pressure calibrator immediately before connection, the gas pressure of the liquid tank (110) immediately before connection, and the pressure of the liquid tank (110) that has reached the equilibrium state after connection. Due to the unclear specific section, this process is repeated to calculate the volume of the liquid tank (100). When the calculated gas volume of the liquid tank (110) converges to a certain level, the calculated gas volume of the liquid tank (110) is used as the gas volume of the liquid tank (110) immediately before liquid injection and is used as a constant when calculating the subsequent liquid injection rate.

[0053] The gas injection amount added into the liquid storage tank (110) from the starting point of a specific section is injected at a level exceeding the capacity of the liquid filled in the liquid bag (120), enabling the calculation of the liquid injection rate until the liquid in the liquid bag (120) is completely discharged.

[0054] According to an embodiment, the control device (150) may be configured to calculate the injection rate of the liquid based on the sensing data of the pressure sensor (160). The control device (150) may be configured to control the driving device (140) so that the injection rate corresponds to a preset rate, thereby adjusting the injection rate of the liquid.

[0055] A detailed description thereof will be given later in FIG. 10.

[0056]

[0057] FIG. 2 is a block diagram showing an example of the driving device of FIG. 1. The driving device (140) may include an encoder (141), a motor (142), and a connection pipe adjuster (143). The encoder (141) may generate position information or speed information of the connection pipe adjuster (143) and provide it to the control device (150). For example, the encoder (141) may measure the rotation of the motor (142) and generate position information or speed information of the connection pipe adjuster (143) based on this.

[0058] The motor (142) may operate according to a control signal of the control device (150). The motor (142) is connected to the connection pipe adjuster (143) and may drive the connection pipe adjuster (143), and the connection pipe adjuster (143) is connected to the liquid connection pipe (130) and may control the injection rate of the liquid flowing through the liquid connection pipe (130). For example, the connection pipe adjuster (143) may control the injection rate of the liquid by adjusting the cross-sectional area of the liquid connection pipe (130).

[0059] Although not shown, the driving device (140) may further include a gear device. According to an embodiment, the motor (142) may drive the connection pipe adjuster (143) through the gear device. The operations of the motor (142) and the gear device are obvious to those of ordinary skill in the art, and thus a detailed description thereof will be omitted.

[0060] According to an embodiment, the control device (150) may determine that an abnormal situation has occurred based on the position information of the connection pipe adjuster (143). The control device (150) may receive the position information of the connection pipe adjuster (143) from the encoder (141) and determine whether the position of the connection pipe adjuster (143) corresponds to the expected position.

[0061] The control device (150) may set the expected position of the connection pipe adjuster (143) to correspond to the set injection rate. If the position information of the connection pipe adjuster (143) received from the encoder (141) is different from the expected position, it may be determined that an abnormal situation has occurred. If the control device (150) determines that an abnormal situation has occurred, it may be configured to generate a warning signal. For example, the abnormal situation may include detachment, blockage, extravasation, etc.

[0062]

[0063] FIGS. 3 and 4 are block diagrams showing examples of the processor of FIG. 2. Referring to FIGS. 1 to 3, the control device (150) may include an interface (151), a processor (152), a memory (153), a communication module (154), and a user interface (155).

[0064] The interface (151) may be configured such that the control device (150) transmits and receives data or information to and from the driving device (140) and the pressure sensor (160). For example, the interface (151) may receive the position information of the connection pipe control unit (143) from the driving device (140), and may provide a control signal for the motor (142) to the driving device (140). In addition, the interface (151) may receive sensing data from the pressure sensor (160).

[0065] The processor (152) may be electrically connected to the interface (151), the memory (153), the communication module (154), and the user interface (155) and may be configured to control each component. The processor (152) may calculate the infusion rate of the liquid based on the sensing data of the pressure sensor (160), and may control the driving device (140) so that the infusion rate corresponds to a preset rate.

[0066] According to an embodiment, the processor (152) may be implemented using at least one of ASICs (application specific integrated circuits), DSPs (digital signal processors), DSPDs (digital signal processing devices), PLDs (programmable logic devices), FPGAs (field programmable gate arrays), processors, controllers, micro - controllers, microprocessors, and other electrical units for performing functions.

[0067] Referring to FIG. 4, the processor (152) may include a calculation unit (1521), a correction unit (1522), a determination unit (1523), and a control unit (1524).

[0068] Referring to FIGS. 1 to 4, the calculation unit (1521) can calculate the amount of the liquid injected into the human body from the liquid bag (120) using Boyle's law. The following mathematical formulas are developed under the assumption that Boyle's law holds, which states that the absolute pressure exerted by a certain mass of ideal gas in a closed system with constant temperature and amount of gas is inversely proportional to the volume it occupies.

[0069] The volume and pressure of the gas inside the liquid tank (110) immediately before liquid injection are and respectively, and the volume and pressure of the gas inside the liquid tank (110) after injecting the liquid and after a unit time are and respectively. Then, according to Boyle's law, holds. Through this, can be expressed as an equation for , and since the injected liquid amount is , it can be expressed as [Equation 1].

[0070] [Equation 1]

[0071]

[0072] Through [Equation 1], the amount of liquid injected per unit time after n unit times can be expressed as [Equation 2].

[0073] [Equation 2]

[0074]

[0075] , , are data that can be obtained through the pressure sensor (160), is the volume of the gas inside the liquid tank (110) immediately before liquid injection ([ is the value limiting the volume of the liquid bag (120) filled with liquid in the inner volume of the liquid tank).

[0076] However, even if the volume of the liquid tank (110) and the capacity of the liquid bag (120) are known, the volume of the liquid bag (120) filled with liquid may vary due to leakage of the liquid during handling, such as removing air from the liquid bag (120). Therefore, the volume of the liquid bag (120) is not constant and must be calculated as follows.

[0077] When the internal pressure of the liquid tank (110) reaches a specific range, a certain amount of gas is additionally injected and sealed using a volumetric calibrator. Then, the calculation unit (1521) uses the ideal gas law equation as follows can be calculated.

[0078] Before a certain amount of gas is additionally introduced, the amount of gas (mole number), volume, pressure, and temperature of the gas inside the liquid tank (110) are respectively , , , , and the amount of gas (mole number), volume, pressure, and temperature of the introduced certain amount of gas are respectively , , , , and after a certain amount of gas is additionally introduced, the volume, pressure, and temperature of the gas inside the liquid tank (110) are respectively , , and, , , there is no difference, so Assuming, according to the ideal gas law equation, [Equation 3], [Equation 4] and [Equation 5] hold.

[0079] [Equation 3]

[0080]

[0081] [Equation 4]

[0082]

[0083] [Equation 5]

[0084]

[0085] Subtracting [Equation 3] from [Equation 5],

[0086]

[0087] In a specific interval, therefore, [Equation 6] can be derived.

[0088] [Equation 6]

[0089]

[0090] Therefore, can be expressed as [Equation 7].[[]END]]

[0091] [Equation 7]

[0092]

[0093] Substituting [Equation 7] into [Equation 2], the liquid injection rate per unit time ( ) can be expressed as [Equation 8]. The liquid injection rate per unit time ( ) can be known from the change in the pressure in the liquid tank according to the change in the gas volume inside the liquid tank (110).

[0094] [Equation 8]

[0095]

[0096] In [Equation 8], is the amount of gas additionally introduced (mole number) in a specific interval, is the temperature, is the ideal gas constant, is the internal pressure of the liquid tank after a certain amount of gas has been introduced in a specific interval, is the internal pressure of the liquid tank immediately before a certain amount of gas is introduced, is the internal pressure of the liquid tank after n unit times, is the internal pressure of the liquid tank after n - 1 unit times.

[0097] However, when injecting a certain amount of gas using a volumetric calibrator in a specific section, the gas amount (mole number) of the injected gas ( ), volume ( ), pressure ( ), and temperature ( ) are expressed by [Equation 4]. At this time, when injecting a gas of a certain volume at 1 atm, Therefore, and, , and are the same, [Equation 9] is derived.

[0098] [Equation 9]

[0099]

[0100] Substituting [Equation 9] into [Equation 8], [Equation 10] is derived.

[0101] [Equation 10]

[0102]

[0103] In [Equation 10], is the volume of the gas at 1 atm additionally introduced in a specific section, is the internal pressure of the liquid tank after a certain amount of gas has been introduced in a specific section, is the internal pressure of the liquid tank immediately before a certain amount of gas is introduced, is the internal pressure of the liquid tank after n unit times, is the internal pressure of the liquid tank after n - 1 unit times.

[0104] Therefore, the calculation unit (1521) receives sensing data from the pressure sensor (160) and can calculate the liquid injection amount per unit time based on [Equation 10] by adding the volume ( ) of the gas at 1 atm introduced in a specific section. The volume ( ) of the gas at 1 atm introduced in a specific section can be received through the user interface (155).

[0105] According to the embodiment, the volume of gas inside the fluid tank (110) immediately before fluid injection is measured using a pressure calibrator. ) can be calculated.

[0106] After filling the pressure calibrator with gas so that the pressure inside the pressure calibrator is higher than the pressure inside the fluid tank (110), the pressure calibrator is connected to the organ (170) of the fluid tank (110). Then, the gas of the pressure calibrator is introduced into the fluid tank (110), and when the pressure of the pressure calibrator and the fluid tank (110) are in pressure equilibrium, the fluid tank (110) is sealed. Thereafter, the control device (150) uses the volume of the pressure calibrator, the pressure of the pressure calibrator just before connection, the gas pressure of the fluid tank (110) just before connection, and the pressure of the fluid tank (110) after connection to determine the volume of the gas inside the fluid tank (110) just before fluid injection. ) can be calculated.

[0107] Before the gas flows into the fluid tank (110) from the pressure calibrator, the pressure and volume of the gas inside the fluid tank (110) are measured respectively. and , the pressure and volume of the gas inside the calibrator, respectively. and And, > When the pressure of the gas inside the liquid tank (110) is in a pressure equilibrium state, ) and volume ( ) is expressed as [Mathematical Formula 11] according to Boyle's law.

[0108] [Equation 11]

[0109]

[0110] Because the liquid tank (110) is sealed after a certain amount of gas is introduced Is is the same as , and if we expand [Equation 11], can be expressed as in [Mathematical Formula 12].

[0111] [Equation 12]

[0112]

[0113] If [Equation 12] is substituted into [Equation 2], the amount of fluid injected per unit time ( ) can be expressed as in [Mathematical Formula 13]. The amount of fluid injected per unit time ( ) can be known by the change in pressure inside the sap tank (110) according to the change in gas volume inside the sap tank (110).

[0114] [Equation 13]

[0115]

[0116] In [Equation 13], is the internal volume of the pressure calibrator, is the internal pressure of the pressure-type calibrator before additional gas introduction, is the pressure of the gas inside the liquid tank (110) in a pressure equilibrium state, is the pressure of the gas inside the sap tank (110) before additional gas inflow, is the internal pressure of the sap tank after n units of time, is the internal pressure of the sap tank after n-1 units of time.

[0117] Therefore, the calculation unit (1521) receives sensing data from the pressure sensor (160) and calculates the internal volume of the pressure calibrator ( ) and the internal pressure of the calibrator before additional gas introduction ( ) can be added to calculate the amount of fluid injected per unit time based on [Mathematical Formula 13]. The internal volume of the pressure calibrator ( ) and the internal pressure of the pressure calibrator before additional gas introduction ( ) can be received through the user interface (155).

[0118] The correction unit (1522) calculates the change in volume of the liquid tank (110) according to pressure in [Mathematical Formula 10] and [Mathematical Formula 13]. It can be further configured to calculate the amount of sap injected per unit time by multiplying a correction factor that takes into account the change in temperature while setting the temperature and injecting the sap.

[0119] According to an embodiment, the fluid tank (110) may include an air bladder, and the correction unit (1522) may improve the accuracy of the calculation by considering the elasticity of the air bladder, Laplace law according to volume change, volume change of the housing due to internal pressure, etc. For example, the correction unit (1522) may be configured to adjust a preset correction coefficient ( ) can be multiplied by [Mathematical Formula 10] or [Mathematical Formula 13] to determine the amount of fluid injected per unit time.

[0120] The judgment unit (1523) may estimate the completion time of the infusion based on the infusion rate (e.g., the amount of infusion per unit time) and provide an alarm at the completion time of the infusion. Depending on the embodiment, the judgment unit (1523) may determine that an abnormality has occurred based on the infusion rate or the position or speed information of the encoder (141). For example, the abnormality may include dislocation, blockage, extravascular leakage, etc.

[0121] According to an embodiment, the judgment unit (1523) may predict the detachment of the infusion needle from the infusion connection tube (130) if the location of the connection tube adjustment unit (143) appears to be a location that compresses the infusion connection tube (130) more than the expected location based on the location information of the encoder (141). Here, the expected location may be set as the first section. For example, the judgment unit (1523) may predict the detachment if the location of the connection tube adjustment unit (143) appears to be a location that compresses the infusion connection tube (130) more than the first section.

[0122] According to an embodiment, the judgment unit (1523) may predict blockage of the fluid injection passage or extravasation of the fluid if the location of the connection tube control unit (143) is further from the expected location to release the fluid connection tube (130) based on the location information of the encoder (141). Here, the expected location may be set to the second section. For example, the judgment unit (1523) may predict blockage or extravasation if the location of the connection tube control unit (143) is further from the second section to release the fluid connection tube (130).

[0123] Depending on the embodiment, the first section and the second section may be the same or different.

[0124] According to an embodiment, the judgment unit (1523) may obtain tightening or loosening speed information of the connection pipe adjustment unit (143) based on the position information or speed information of the encoder (141). The judgment unit (1523) may predict a breakaway if the tightening speed of the connection pipe adjustment unit (143) deviates from the first section and is higher than the reference value based on the speed information of the encoder (141). Alternatively, the judgment unit (1523) may predict a blockage if the loosening speed of the connection pipe adjustment unit (143) deviates from the second section and is higher than the reference value based on the speed information of the encoder (141). Alternatively, the control device (150) may predict an extravascular leak if the loosening speed of the connection pipe adjustment unit (143) deviates from the second section and is lower than the reference value based on the speed information of the encoder (141).

[0125] The above-described example explains the principle by which the judgment unit (1523) determines that an abnormal situation has occurred based on the position information or speed information of the encoder (141), but is not limited thereto. That is, the judgment unit (1523) can determine that an abnormal situation has occurred by determining whether the injection speed of the fluid is faster or slower than the expected speed. According to an embodiment, the judgment unit (1523) can generate a warning signal if it determines that an abnormal situation has occurred.

[0126] The control unit (1524) may be configured to generate a control signal for the driving device (140) based on the judgment of the judgment unit (1523). The driving device (140) may adjust the cross-sectional area of ​​the sap connecting tube (130) based on the control signal.

[0127]

[0128] Referring again to FIG. 3, the processor (152) may be implemented in various types such as an AP (Application Processor), a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), etc., and may be any semiconductor device that executes instructions stored in a memory (153) or a storage device.

[0129] The memory (153) may include various types of volatile or non-volatile storage media. For example, the memory (153) may include ROM and RAM. Depending on the embodiment, the memory (153) may be located inside or outside the processor (152), and the memory (153) may be connected to the processor (152) via various known means.

[0130] According to an embodiment, the memory (153) may store a program including one or more instructions. The memory (153) may store at least one of instructions, an algorithm, a data structure, a program code, and an application program that can be read by the processor (152). The instructions, algorithms, data structures, and program code stored in the memory (153) may be implemented in a programming or scripting language such as, for example, C, C++, Java, or an assembler.

[0131] The communication module (154) can communicate with other electronic devices or external devices under the control of the control device (150). The communication module (154) can communicate through a network connection or a device-to-device connection via wireless or wired communication. The wireless communication may include, for example, at least one of Wi-Fi (wireless fidelity), BT (bluetooth), NFC (near field communication), GPS (global positioning system), or cellular communication (for example, LTE, LTE-A, CDMA, WCDMA, UMTS, WiBro, or GSM). The wired communication may include, for example, at least one of USB (universal serial bus), HDMI (high definition multimedia interface), RS-232 (recommended standard 232), or POTS (plain old telephone service).

[0132] The user interface (155) may be a device for communication between the automatic IV injector (100) and a user. The user interface (155) may receive user input and provide the user with information generated by the automatic IV injector (100). The automatic IV injector (100) may implement a UI (User Interface) or UX (User Experience) through the user interface (155).

[0133] The user interface (155) may include an input section and an output section. Depending on the embodiment, the user interface (155) may include other components in addition to the described components, or may not include some of the described components.

[0134] According to an embodiment, the input unit may be configured to receive a user command from a user. For example, the input unit may include at least one of a voice input unit including a microphone or the like, a touch input unit including a touch sensor or the like, and a mechanical input unit including a button or the like.

[0135] According to an embodiment, the output unit may be configured to generate output related to visual, auditory, or tactile sensations. The output unit may include at least one of a display unit, an LED, an audio output unit, and a haptic output unit.

[0136]

[0137] FIG. 5 is a drawing showing a fluid tank and a fluid bag according to an embodiment of the present invention. Referring to FIGS. 1 to 5, the fluid tank (110) may include a housing (111), air bladders (112-1, 112-2), and a fixing member (113). The housing (111) forms the outer shape of the fluid tank (110), and its volume may not change or may be below a certain level due to changes in internal pressure. That is, the housing (111) may have a strength above a certain level, and may be configured to have a weight below a standard weight in consideration of portability. For example, the housing (111) may be made of PC (polycarbonate).

[0138] The housing (111) may be configured to have air bladders (112-1, 112-2) installed therein and to accommodate a fluid bag (120). The air bladders (112-1, 112-2) are made of elastic material, and the air bladders (112-1, 112-2) may be connected to a trachea (170). That is, gas in the air bladders (112-1, 112-2) may be introduced or discharged through the trachea (170).

[0139] The engine (170) may be equipped with a pressure sensor (160), an opening / closing device (180), and a connecting portion (190). The pressure sensor (160) can measure the pressure within the engine (170), the opening / closing device (180) can control the flow of gas passing through the engine, and the connecting portion (190) can be configured to connect the engine (170) and a gas injector or calibrator. The connecting portion is illustrated as having an inner diameter larger than the inner diameter of the engine in the form of a cylindrical pipe, but conversely, the outer diameter of the connecting portion may be formed smaller than the outer diameter of the engine.

[0140] There may be one or more air bladders (112-1, 112-2). The first air bladder (112-1) and the second air bladder (112-2) may have a balloon shape. As gas flows into the first air bladder (112-1) and the second air bladder (112-2) through the organ (170), the volumes of the first air bladder (112-1) and the second air bladder (112-2) increase, and as the volumes of the first air bladder (112-1) and the second air bladder (112-2) increase, the first air bladder (112-1) and the second air bladder (112-2) may be tightly attached to the IV bag (120).

[0141] For convenience of explanation, the air pockets (112-1, 112-2) are illustrated as consisting of two, but the number of air pockets is not limited thereto.

[0142] The fixing member (113) may be configured to fix the infusion bag (120). For example, the fixing member (113) may include a hole configured to fix the infusion bag (120) by inserting the infusion outlet (122). Depending on the embodiment, there may be a plurality of holes for fixing the infusion outlet (122) or the infusion injection unit (not shown) of the infusion bag (120). The fixing member (113) is mounted on the outside of the housing (111), but a portion thereof enters the inside of the housing (111), so that a portion of the infusion outlet (122) can be compressed by the air bladders (112-1, 112-2).

[0143] According to an embodiment, the fixing member (113) may be configured to be detachably attached to the housing (111). The housing (111) may include an opening, and the fixing member (113) may be inserted into the opening and fixed to the housing (111). FIG. 6 is a drawing showing a scene in which a fluid bag (120) is fixed to the fixing member (113) and then stored inside the fluid tank (110). Referring to FIG. 6, the fixing member (113) may be detachably attached to or attached to the housing (111) of the fluid tank (110) in a state in which the fluid outlet (122) of the fluid bag (120) is inserted and fixed.

[0144] The IV bag (120) can be fixed to the fixing member (113) through the IV outlet (122) while filled with IV fluid. The fixing member (113) is mounted on the housing (111), and the gas introduced from the organ (170) is stored inside the air bladder (112-1, 112-2), but the air bladder (112-1, 112-2) and the IV bag (120) are not in close contact until a certain amount of gas is introduced, so that the internal pressure of the air bladder (112-1, 112-2) can be constant.

[0145] According to an embodiment, the fixing member (113) may be configured to discharge air existing between the air bladders (112-1, 112-2) and the intravenous bag (120) to the outside of the housing (111) as the air bladders (112-1, 112-2) are pressed against the intravenous bag (120). As a result, the pressure of the gas inside the air bladders (112-1, 112-2) and the volume of the intravenous bag (120) influence each other as described in [Mathematical Formula 1] to [Mathematical Formula 13]. A detailed description thereof will be described later with reference to FIGS. 7 to 14.

[0146] FIGS. 7 to 14 are drawings explaining the operating method of the fluid tank (110) according to FIG. 5. FIGS. 7 to 10 are drawings showing a scene where gas is introduced into the air bladder (112-1, 112-2), FIG. 11 is a drawing showing a scene where an opening and closing device is locked, FIG. 12 is a drawing showing a scene where additional gas is introduced into the air bladder (112-1, 112-2) through a calibrator, FIG. 13 is a drawing showing a scene where the opening and closing device is locked again, and FIG. 14 is a drawing showing a scene where the volume of the fluid bag (120) is reduced as fluid flows out of the fluid bag (120).

[0147] Referring to FIGS. 7 and 8, as gas flows into the organ (170), the air bladders (112-1, 112-2) may be pressed against the infusion bag (120). Specifically, the air bladders (112-1, 112-2) may first be pressed against a part of the infusion bag (120). That is, the space between the air bladders (112-1, 112-2) and the infusion bag (120) may be reduced, and the air existing between the air bladders (212-1, 212-2) and the infusion bag (120) may be discharged to the outside through the gap between the fixing part (113) and the housing (111), and the gap between the hole of the fixing part (113) and the infusion outlet (122).

[0148] Referring to FIGS. 9 and 10, when a certain amount of gas is introduced from the organ (170), the air bladders (112-1, 112-2) are pressed against the infusion bag (120), and the pressure inside the air bladders (112-1, 112-2) presses the infusion bag (120). At this time, a wall is formed by the housing (111) and the fixing member (113), so that the air bladder cannot expand outside the infusion tank. In addition, since the connecting pipe (130, not shown) connected to the infusion outlet (122) is blocked, the infusion bag (120) cannot be discharged, so that there is no change in the volume of the infusion bag (120). Therefore, the volume of the air bladders (112-1, 112-2) does not increase due to the introduction of additional gas. From then on, when gas is introduced, the pressure inside the air pockets (112-1, 112-2) may increase proportionally. The control device (150) may determine the corresponding point in time (specific section) through the pressure sensor (160).

[0149] Referring to Fig. 11, the opening / closing device (180) can block the inflow and outflow of gas through a locking operation. That is, in a specific section, the opening / closing device (180) can operate to block the inflow and outflow of gas through the engine (170). According to an embodiment, a calibrator (not shown) can be connected to the engine (170) at this time. In this case, a connecting part (190) can be configured to connect the engine (170) and the calibrator. At this time, the pressure of the air bladder (112-1, 112-2), i.e., the pressure of the fluid tank (110) before additional gas inflow, is measured using a pressure sensor (160) installed in the engine. ) can be obtained.

[0150] And, in case of using a calibrator such as a syringe that additionally injects a certain amount of gas, the volume of gas to be additionally injected ( ) can be known, and in the case of using a calibrator with a pressure sensor installed and a constant inner product, the inner product of the calibrator ( ) and the pressure of the gas filled in the calibrator with the pressure sensor of the calibrator ( ) can be known.

[0151] Referring to FIG. 12, the opening / closing device (180) is opened, and the calibrator can additionally introduce gas into the air pockets (112-1, 112-2).

[0152] Referring to Fig. 13, after additional gas inflow, the opening / closing device (180) is locked again, and the calibrator is separated from the connecting part (190). At this time, the pressure of the fluid tank just before the fluid injection is measured by the pressure sensor (160) connected to the engine. ) is measured. Afterwards, the driving device (140) of the sap connecting pipe (130) is operated to inject the sap.

[0153] Referring to Fig. 14, as the amount of fluid injected into the patient from the IV bag (120) decreases, the volume of the IV bag (120) decreases (dV), and correspondingly, the volume of the gas present inside the air bladder (112-1, 112-2) increases, thereby decreasing the pressure.

[0154] In FIGS. 13 and 14, the control device (150) controls the sap injection speed using [Mathematical Formula 10] or [Mathematical Formula 13].

[0155] Figure 15 is a diagram illustrating a specific section in which an automatic injector according to an embodiment of the present invention operates. Referring to Figures 7 to 14, as gas flows into the housing (111), the internal pressure may increase. However, the amount of gas flowing in may be proportional to the internal pressure only in a specific section.

[0156] As shown in Fig. 7, the internal pressure may be constant at the beginning when gas is introduced. For example, it may correspond to atmospheric pressure, and this section may correspond to the dashed-dotted line in Fig. 15. As shown in Figs. 8 and 9, the section where the air bladders (112-1, 112-2) come into close contact with the IV bag (120) as gas is introduced may correspond to the dashed-dotted line in Fig. 15. In this section, the internal pressure generally increases according to the amount of introduced gas, but it may be a section where the pressure increases nonlinearly and sometimes decreases. As shown in Fig. 10, after the air bladders (112-1, 112-2) are completely in close contact with the IV bag (120; 121, 122), a specific section may be entered where the amount of introduced gas is proportional to the internal pressure. That is, the specific section may correspond to the straight section in Fig. 15.

[0157] In Fig. 15, the appearance of a dashed-dotted line section or a dotted-dotted line section is a phenomenon that occurs when gas is filled into an air bladder using an elastic body. Therefore, in a non-air bladder-type infusion tank without an air bladder, the dashed-dotted line section or the dotted-dotted line section may be short or absent depending on the flexibility of the elastic body that seals the infusion outlet of the infusion tank or the infusion connection pipe connected to the infusion outlet pipe.

[0158] Fig. 16 is a drawing showing the application of a fluid tank (210), a fluid bag (220), a pressure sensor (260), and an organ (270) according to another embodiment of the present invention. Elastic bodies (EL1, EL2) are coupled to a part of a housing (211) to form air bladders (212-1, 212-2) in which a space capable of containing air is provided between the elastic bodies (EL1, EL2) and the housing (211). The organ (270) is connected to the housing (211) forming the air bladders (212-1, 212-2) to enable gas to enter and exit the interior of the air bladders (212-1, 212-2). Other parts are similar to Fig. 5, and thus a detailed description thereof will be omitted.

[0159] According to an embodiment, the elastic bodies (EL1, EL2) may be configured as concave curved surfaces, because the pressure of the air bladders (212-1, 212-2) is set to negative pressure to facilitate storage of the IV bag (220). For convenience of explanation, the air bladders (212-1, 212-2) are illustrated as consisting of two, but the number of air bladders (212-1, 212-2) is not limited thereto.

[0160] Fig. 17 is a drawing showing a calibrator according to one embodiment of the present invention. The calibrator may include a first opening / closing device (301), a second opening / closing device (302), a pressure sensor (303), a container (304), an organ (306), and an inlet (306). The organ (306) may be a gas passage connecting the first opening / closing device (301), the second opening / closing device (302), the pressure sensor (303), and the container (304).

[0161] The calibrator may be a pressure-type calibrator that has a container (304) with a fixed volume and a shieldable structure and a pressure sensor (303) installed therein to measure the internal pressure. Gas can be injected into the container (304) through an injection port (306), and an opening / closing device (302) is installed between the container (304) and the injection port (306) to control the injection of gas.

[0162] The gas stored in the container (304) can be injected into the fluid tank (110, 210) through the connection (290) under the control of the opening / closing device (301). That is, the calibrator is connected to the connection (290) and can introduce gas into the fluid tank (110, 210). When the pressures of the calibrator and the fluid tank (110, 210) reach pressure equilibrium, the fluid tank (110, 210) is sealed.

[0163] The above-described embodiments are specific examples for practicing the present invention. The present invention will encompass not only the above-described embodiments, but also embodiments that can be simply designed or easily modified. Furthermore, the present invention will encompass techniques that can be easily modified and implemented using the embodiments. Therefore, the scope of the present invention should not be limited to the above-described embodiments, but should be defined not only by the claims set forth below, but also by equivalents of the claims of the present invention.

Claims

1. A sap bag filled with sap inside; A connecting tube configured to be connected to the above-mentioned IV bag and to form a passage through which the IV bag's internal fluid is injected to an external patient; A fluid tank in which the fluid bag is stored inside and an organ capable of allowing gas entry and exit and shielding is installed outside; A driving device configured to adjust the cross-sectional area of ​​the above connecting pipe; A pressure sensor installed in the above organ or the above fluid tank and configured to measure the internal pressure of the fluid tank; and A control device configured to measure the pressure of the gas in the fluid tank by using the correspondence between the volume of the injected fluid and the change in the volume of the gas in the fluid tank when the injected fluid is injected into the fluid tank through the above-mentioned organ and sealed, and to calculate the amount of the injected fluid by measuring the pressure of the gas in the fluid tank by using the correspondence between the volume of the injected fluid and the change in the volume of the gas in the fluid tank, An automatic fluid injector characterized in that the control device is further configured to calculate the injection speed based on the sensing data of the pressure sensor and control the driving device so that the injection speed corresponds to a predetermined speed.

2. In paragraph 1, The above sap tank: A housing forming the outer shape of the above sap tank; An air bladder located inside the housing, connected to the organ, and expanding as a certain amount of gas flows in to seal the fluid bag; and An automatic intravenous injector characterized in that it further includes a fixing part that is detachably attached to the housing and configured to receive and fix the intravenous bag inside the housing.

3. In paragraph 2, An automatic fluid injector characterized in that the housing has a volume change that is below a certain level according to a change in the internal pressure.

4. In paragraph 2, An automatic IV injector characterized in that the air pocket is composed of an elastic body in the form of a balloon or a space between one side of the housing and the elastic body.

5. In paragraph 2, An automatic intravenous injector characterized in that the fixing member includes a hole through which the intravenous outlet of the intravenous bag is fixed and through which the intravenous outlet is exposed to the outside of the intravenous tank so as to be connected to the connecting tube.

6. In paragraph 1, The above driving device: A connecting pipe adjusting unit configured to adjust the cross-sectional area by pressing the connecting pipe; A motor driving the above connecting pipe control unit; and An automatic infusion pump characterized in that it further comprises an encoder configured to measure the rotation of the motor and generate position information of the connecting tube control unit.

7. In paragraph 6, An automatic IV injector characterized in that the control device is configured to determine that an abnormal situation has occurred and generate a warning signal when it determines that the position of the connecting pipe control unit is different from the expected position based on the position information.

8. In paragraph 1, An automatic fluid injector characterized in that the control device, when a certain amount of gas flows into the fluid tank through the organ, confirms entry into a specific section in which the amount of gas flowing in is proportional to the internal pressure based on the sensing data.

9. In paragraph 8, An automatic fluid injector further comprising a calibrator that opens the opening / closing device and introduces additional gas into the fluid tank when entry into the specific section is confirmed.

10. In paragraph 9, The above calibrator is a volume type calibrator, An automatic infusion injector characterized in that the control device is further configured to calculate the amount of infusion per unit time corresponding to the injection speed by calculating the volume of the internal gas of the infusion tank using the change in gas pressure within the infusion tank before and after the additional gas is introduced after injecting a fixed amount of the additional gas using the volume calibrator.

11. In paragraph 9, The above calibrator is a pressure type calibrator, An automatic intravenous injector characterized in that the control device is further configured to calculate the intravenous injection amount per unit time corresponding to the injection speed by calculating the volume of the internal gas of the intravenous tank using the gas pressure inside the intravenous tank before and after the additional gas introduction using the pressure calibrator, the gas pressure of the pressure calibrator before the additional gas introduction, and the volume of the pressure calibrator.

12. In paragraph 10 or 11, An automatic fluid injector characterized in that the control device is further configured to calculate the amount of fluid injected per unit time by taking into account a correction factor for a change in the volume of the internal gas according to pressure.

Images