Infusion control system based on capacitive liquid level sensor

Abstract

The invention relates to the technical field of electronic medical instruments, in particular to an infusion control system based on a capacitive liquid level sensor. The infusion control system comprises a capacitive liquid level sensor which is nested and matched with the outside of an infusion hose on the lower side of a liquid medicine filter; based on an induction detection module and a signal transmission module of a capacitive liquid level sensor, the liquid level height change of liquid medicine in an infusion hose on the lower side of a liquid medicine filter is converted into a voltage signal; a voltage signal sent by the signal transmission module is received through the control IC, and whether liquid medicine exists in the infusion hose or not is judged; on the basis of the judgment result, an audible and visual alarm is timely triggered for early warning, and early warning infusion information is displayed through a monitoring display; compared with a traditional infusion pump, the infusion control system has the advantages that the material cost is greatly reduced; compared with manual nursing infusion, the infusion control system is more accurate in infusion control degree.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic medical equipment, and in particular to an infusion control system based on a capacitive liquid level sensor. Background Art

[0002] Intravenous infusion is one of the most common and important treatment methods in clinical practice. It is used frequently and has a wide range of applications. However, its process currently cannot be intelligently controlled. Medical staff, patients, and their families need to pay attention to the decline of the drug solution and perform operations such as changing the dressing or removing the needle when the drug solution is about to run out.

[0003] Existing infusion process control can be mainly divided into two methods: manual observation control and infusion pump control. Manual observation control has the widest application range. It is not limited by facilities and site conditions and is based on subjective experience and judgment. Medical staff, patients and their families need to pay attention to the status of the drug solution at all times. There is a certain risk of misdiagnosis and omission. Infusion pump control improves the controllability of the infusion process by precisely controlling the number of infusion drops or flow rate, so that the drug solution is uniformly and stably delivered to the patient's body. It is often used for acute and critically ill patients who need to strictly control the infusion volume and drug dosage. However, this control method is relatively expensive and has a limited scope of actual application.

[0004] Based on the above existing technical problems, a liquid infusion control system based on a capacitive liquid level sensor is proposed. Summary of the Invention

[0005] In view of the above-mentioned shortcomings and deficiencies of the prior art, the present invention provides an infusion control system based on a capacitive liquid level sensor, which solves the technical problem existing in the existing infusion control process of "how to improve the accuracy of infusion control while reducing the cost of infusion control".

[0006] In order to achieve the above objectives, the main technical solutions adopted by the present invention include: The present invention provides an infusion control system based on a capacitive liquid level sensor, specifically: The capacitive liquid level sensor is connected to the signal controller via wireless communication; The capacitive liquid level sensor is nested and adapted to the outside of the infusion hose at the lower side of the liquid filter; the capacitive liquid level sensor is provided with: an induction detection module and a signal transmission module for signal communication connection; For the induction detection module, the first voltage divider resistor branch / the second voltage divider resistor branch is connected to the positive input terminal / negative input terminal of the operational amplifier, and the variable coupling capacitor is connected in parallel between the two aforementioned resistance branches; the bias capacitor is connected to the negative power supply terminal of the operational amplifier, the bias resistor is connected to the positive input terminal of the operational amplifier, and the two ends of the feedback resistor are respectively connected to the negative input terminal and the output terminal of the operational amplifier; the output terminal of the operational amplifier is connected to a two-stage low-pass filter.

[0007] The first voltage-dividing resistor branch has a structure in which a first voltage-dividing resistor is connected in series with a second voltage-dividing resistor; The second voltage-dividing resistor branch has a structure in which a third voltage-dividing resistor is connected in series with a fourth voltage-dividing resistor; The variable coupling capacitor has a combined structure of a fixed electrode - movable electrode; The low-pass filter has a structure of a resistor connected to a capacitor.

[0008] Optionally, the first voltage-dividing resistor branch, the second voltage-dividing resistor branch, and the variable coupling capacitor form a voltage-dividing coupling circuit; the bias capacitor, the operational amplifier, the bias resistor, and the feedback resistor form a differential input operational amplifier circuit; the two-stage low-pass filter forms a low-pass filtering circuit.

[0009] Optionally, the signal transmission module is composed of a current-limiting resistor, a coupling capacitor, a collector load resistor, a first triode, a base bias resistor, a second triode, a field effect transistor, a first diode, a second diode, and a pull-down resistor.

[0010] Optionally, based on the change in the liquid level height of the liquid inside the lower infusion hose of the liquid medicine filter, the voltage-dividing coupling circuit generates a change in capacitance value to generate an electrode phase difference; The differential input operational amplifier circuit converts the electrode phase difference into a differential capacitance signal and amplifies the differential capacitance signal; the low-pass filtering circuit removes high-frequency noise from the differential capacitance signal.

[0011] Optionally, the first triode amplifies the differential capacitance signal in terms of current, the collector load resistor converts the differential capacitance signal into a voltage signal, and the second triode amplifies the voltage signal; The field effect transistor buffers and isolates the voltage signal; the first diode in combination with the second diode clamps and protects the voltage signal.

[0012] Optionally, the monitoring display and the audible and visual alarm are respectively wirelessly communicatively connected to the signal controller; The signal controller is internally provided with a control IC.

[0013] Optionally, the control IC receives the voltage signal sent by the signal transmission module and judges whether there is liquid medicine in the infusion hose based on a preset judgment condition; Optionally, the preset judgment condition is: When the control IC does not continuously receive the voltage signal, there is still liquid medicine in the infusion hose; When the control IC continuously receives the voltage signal and the continuous reception duration reaches the preset duration, there is no liquid medicine in the infusion hose.

[0014] Optionally, when it is judged that there is no liquid medicine in the infusion hose, while the audible and visual alarm triggers a warning, the monitoring display shows the information of the infusion device corresponding to the current capacitive liquid level sensor.

[0015] The beneficial effects of this application are as follows: This infusion control system includes: a capacitive liquid level sensor nested and adapted to the outside of the infusion hose below the liquid medicine filter; an induction detection module and a signal transmission module based on the capacitive liquid level sensor, which convert the change in the liquid level height of the liquid medicine inside the infusion hose below the liquid medicine filter into a voltage signal; and a control IC receives the voltage signal sent by the signal transmission module to judge whether there is liquid medicine in the infusion hose; based on the foregoing judgment result, an acoustic-optical alarm is triggered in a timely manner for warning, and the warning infusion information is displayed through a monitoring display. Compared with an infusion pump, the material cost of the foregoing system is greatly reduced; compared with manual infusion care, the infusion control degree of the foregoing system is more accurate. Brief Description of the Drawings Figure 1 It is a schematic diagram of the component structure of the infusion control system provided by an embodiment of the present invention; Figure 2 It is a schematic diagram of the structure of an infusion set provided by an embodiment of the present invention; Figure 3 It is a schematic diagram of the internal structure of the capacitive liquid level sensor provided by an embodiment of the present invention; Figure 4 It is a flow chart of the operation method of the infusion control system provided by an embodiment of the present invention; Figures 1 to 4 The component numbers in [figures] correspond to the following: Infusion set 1, capacitive liquid level sensor 2, monitoring display 3, signal controller 4, WIFI wireless transmission module 5, acoustic-optical alarm 6, hanging bottle 7, bottle stopper puncture device 8, liquid medicine filter 9, infusion hose 10, drip chamber 11, flow rate regulator 12, air filter 13, intravenous injection needle 14, operational amplifier 15, first voltage dividing resistor 16, second voltage dividing resistor 17, third voltage dividing resistor 18, fourth voltage dividing resistor 19, variable coupling capacitor 20, bias capacitor 21, bias resistor 22, feedback resistor 23, first-stage low-pass filter 24, second-stage low-pass filter 25, current limiting resistor 26, coupling capacitor 27, collector load resistor 28, first triode 29, base bias resistor 30, second triode 31, field effect transistor 32, first diode 33, second diode 34, pull-down resistor 35. Detailed Description of the Embodiment

[0017] In order to better explain the present invention for easy understanding, the present invention will be described in detail below with reference to the drawings through specific embodiments.

[0018] To better understand the above technical solution, the exemplary embodiments of the present invention will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more clear and thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.

[0019] Embodiment 1 In order to make the technical problems, technical solutions and beneficial effects solved by the present invention more clear, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments.

[0020] This specific embodiment is only an interpretation of the present invention and not a limitation thereof. Any equivalent changes made according to the structure, shape and principle of the present invention shall be covered within the protection scope of this application.

[0021] This embodiment relates to an infusion control system based on a capacitive liquid level sensor, specifically as Figure 1 shown, Figure 1 is a schematic diagram of the component structure of the infusion control system. Among them, the capacitive liquid level sensor 2, the monitoring display 3, and the audible and visual alarm 6 are respectively communicatively connected to the signal controller 4 based on the corresponding WIFI wireless transmission module 5; among them, a control IC is provided inside the signal controller 4.

[0022] It should be noted that: each capacitive liquid level sensor 2 is correspondingly installed on a set of infusion sets 1, and the signal controller 4 is communicatively connected to one or more capacitive liquid level sensors 2, so as to realize: the signal controller 4 controls the infusion of one or more sets of infusion sets 1.

[0023] In this embodiment, as Figure 2 shown, Figure 2 is a schematic diagram of the structure of the infusion set. A set of infusion sets 1 includes: a hanging bottle 7, a bottle stopper puncture device 8, a liquid medicine filter 9, an infusion hose 10, a drip chamber 11, a flow rate regulator 12, an air filter 13, and an intravenous injection needle 14; based on the structure of the aforementioned infusion set 1, it can be known that: the liquid medicine in the hanging bottle 7 flows into the drip chamber 11 based on the liquid medicine filter 9 and the infusion hose 10, and the liquid medicine in the drip chamber 11 is injected into the patient's body based on the infusion hose 10 and the intravenous injection needle 14; Since the drip chamber 11 serves as a "transition transfer station" during the infusion process and there is a certain height difference between the liquid medicine filter 9 and the drip chamber 11, it is most appropriate to design the capacitive liquid level sensor 2 as a detachable assembly structure "nested and adapted to the outside of the infusion hose 10 below the liquid medicine filter 9"; the detachable assembly structure of the capacitive liquid level sensor 2 ensures that the device can be reused; preferably, the height difference between the top of the capacitive liquid level sensor 2 and the bottom of the infusion hose 10 is not greater than 3 cm, ensuring pre-warning based on the sensing and monitoring results, reserving time for the medical staff to remove the needle and change the dressing, and ensuring absolute safety.

[0024] In this embodiment, as Figure 3 shown, Figure 3 is a schematic diagram of the internal structure of the capacitive liquid level sensor. Among them, the capacitive liquid level sensor 2 is provided with: an induction detection module and a signal transmission module connected by signal communication; The circuit structure corresponding to the induction detection module is: the first voltage-dividing resistor branch is connected to the positive input terminal of the operational amplifier 15, and the second voltage-dividing resistor branch is connected to the negative input terminal of the operational amplifier 15. Among them, the first voltage-dividing resistor branch is a structure in which the first voltage-dividing resistor 16 is connected in series with the second voltage-dividing resistor 17, and the second voltage-dividing resistor branch is a structure in which the third voltage-dividing resistor 18 is connected in series with the fourth voltage-dividing resistor 19; the variable coupling capacitor 20 is connected in parallel between the aforementioned first voltage-dividing resistor branch and the second voltage-dividing resistor branch, and the variable coupling capacitor 20 is a combination structure of a fixed electrode - a moving electrode; the bias capacitor 21 is connected to the negative power supply terminal of the operational amplifier 15, the bias resistor 22 is connected to the positive input terminal of the operational amplifier 15, and both ends of the feedback resistor 23 are respectively connected to the negative input terminal and the output terminal of the operational amplifier 15; the output terminal of the operational amplifier 15 is connected to a two-stage low-pass filter. Among them, the first-stage low-pass filter 24 and the second-stage low-pass filter 25 are both structures in which a resistor is connected to a capacitor.

[0025] The signal transmission module is composed of a current-limiting resistor 26, a coupling capacitor 27, a collector load resistor 28, a first triode 29, a base bias resistor 30, a second triode 31, a field effect transistor 32, a first diode 33, a second diode 34, and a pull-down resistor 35.

[0026] In this embodiment, when the current infusion bottle 7 is approaching the end of the infusion, the liquid level of the liquid medicine in the infusion hose 10 gradually decreases; based on the structure of the aforementioned capacitive liquid level sensor 2, in the case of "nesting and installing the capacitive liquid level sensor 2 on the outside of the infusion hose 10 below the liquid medicine filter 9", when the liquid level of the liquid medicine in the infusion hose 10 is higher than the induction detection area of the capacitive liquid level sensor 2, the parasitic capacitance of the liquid medicine is coupled with the static capacitance, and when the liquid level of the liquid medicine in the infusion hose 10 is lower than the induction detection area of the capacitive liquid level sensor 2, the capacitive coupling disappears; In this embodiment, as Figure 3 shown, the first voltage-dividing resistor branch, the second voltage-dividing resistor branch, and the variable coupling capacitor 20 form a voltage-dividing coupling circuit A; the bias capacitor 21, the operational amplifier 15, the bias resistor 22, and the feedback resistor 23 form a differential input operational amplifier circuit B; the first-stage low-pass filter 24 and the second-stage low-pass filter 25 form a low-pass filter circuit C; In this embodiment, as Figure 3 shown, when the variable coupling capacitor 20 in the voltage-dividing coupling circuit A has the aforementioned "capacitance coupling disappearance", the capacitance value of the variable coupling capacitor 20 changes, generating an electrode phase difference between the fixed electrode and the moving electrode, thereby causing a phase shift in the signals at the positive and negative input terminals of the operational amplifier 15. The differential input operational amplifier circuit B converts the phase difference between the fixed electrode and the moving electrode into a differential capacitance signal and amplifies the signal; the low-pass filter circuit C removes high-frequency noise from the amplified differential capacitance signal; the differential capacitance signal after high-frequency noise removal is transmitted to the signal transmission module; In this embodiment, as Figure 3 shown, the differential capacitance signal output by the induction detection module is coupled to the base of the first triode 29 through the coupling capacitor 27. The first triode 29 amplifies the current of the differential capacitance signal; the amplified differential capacitance signal is converted into a voltage signal through the collector load resistor 28 and the voltage signal is input to the base of the second triode 31 for voltage signal amplification; the amplified voltage signal is buffered and isolated by the field effect transistor 32; the voltage signal after buffering and isolation is clamped and protected based on the first diode 33 and the second diode 34 to ensure that the voltage of the output voltage signal is within a safe range; the signal transmission module transmits the voltage signal after clamping and protection to the control IC.

[0027] In this embodiment, the control IC receives the voltage signal sent by the signal transmission module and judges whether there is liquid medicine in the infusion hose 10 based on a preset judgment condition; Among them, the preset judgment condition is: When the control IC does not continuously receive the voltage signal, there is still liquid medicine in the infusion hose 10; When the control IC continuously receives the voltage signal and the continuous reception duration reaches the preset duration, there is no liquid medicine in the infusion hose 10.

[0028] Regarding the aforementioned preset judgment condition, it should be noted that: When the control IC receives the voltage signal sent by the signal transmission module, it indicates that there is a "no liquid medicine" vacancy inside the infusion hose 10 of the nested part of the capacitive liquid level sensor 2. Therefore, when the control IC does not continuously receive the voltage signal, it may be that there are small air bubbles inside the infusion hose 10, and the infusion process is still normal. When the control IC continuously receives the voltage signal and the continuous reception duration reaches the preset duration, it indicates that the liquid level height of the liquid medicine in the infusion hose 10 is indeed lower than the induction detection area of the capacitive liquid level sensor 2. When it is determined that there is no liquid medicine in the infusion hose 10, the control IC simultaneously sends instructions to the monitoring display 3 and the sound and light alarm 6. While the sound and light alarm 6 triggers a warning, the monitoring display 3 displays the information of the infusion set corresponding to the current capacitive liquid level sensor 2. The monitoring display 3 uses a TFT-LCD liquid crystal display screen. The light-emitting component corresponding to the sound and light alarm 6 uses a light-emitting diode, and the sound-generating component corresponding to the sound and light alarm 6 uses an active buzzer oscillator. Since the signal controller 4 is communicatively connected to one or more capacitive liquid level sensors 2, when the signal controller 4 is communicatively connected to multiple capacitive liquid level sensors 2, the infusion set information displays the specific arrangement serial numbers of the capacitive liquid level sensors 2 that trigger the infusion control warning. Based on the specific arrangement serial numbers of the capacitive liquid level sensors 2 displayed by the infusion set information, medical staff can quickly perform needle removal or dressing change operations.

[0029] In this embodiment, regarding the "preset duration" in the foregoing preset judgment conditions, it should be noted that: Since the drip chamber 11 is the "transition transfer station" in the infusion process, in order to ensure the personal safety of the patient during infusion, preferably, it is necessary to prepare for needle removal or dressing change before the liquid level of the liquid medicine in the infusion hose 10 is lower than the height of the drip chamber 11. The "preset duration" is less than the duration for the liquid level of the liquid medicine to flow from the height of the capacitive liquid level sensor 2 to the height of the drip chamber 11. The specific duration of the "preset duration" is not limited and is specifically determined based on the liquid medicine flow rate adjusted by the flow regulator 12.

[0030] For the infusion control system based on the capacitive liquid level sensor described in the foregoing Embodiment 1, this infusion control system includes: a capacitive liquid level sensor nested and adapted to the "outside of the infusion hose below the liquid medicine filter"; an induction detection module and a signal transmission module based on the capacitive liquid level sensor, which convert the change in the liquid level height of the liquid medicine inside the infusion hose below the liquid medicine filter into a voltage signal; and the control IC receives the voltage signal sent by the signal transmission module to judge whether there is liquid medicine in the infusion hose; based on the foregoing judgment result, trigger the warning of the sound and light alarm in a timely manner, and display the warning infusion information through the monitoring display. Compared with an infusion pump, the material cost of the foregoing system is greatly reduced; compared with manual infusion care, the infusion control degree of the foregoing system is more accurate.

[0031] Embodiment 2 This embodiment relates to an operation method based on the infusion control system described in the foregoing Embodiment 1. The operation method is as Figure 4 shown in Figure 4 a flowchart of the operation method of the infusion control system; S1. When a patient is receiving an infusion, a capacitive liquid level sensor is nested and installed outside the infusion hose under a preset liquid medicine filter; S2. The infusion control system is adjusted to the powered-on state to ensure that the capacitive liquid level sensor, the monitoring display, and the sound and light alarm are respectively connected to the signal controller based on wireless communication; S3. When the liquid level height of the liquid medicine in the infusion hose is lower than the induction detection area of the capacitive liquid level sensor, while triggering the early warning of the sound and light alarm, the signal controller displays the information of the infusion set based on the monitoring display; S4. Based on the information of the infusion set displayed by the infusion set information, medical staff perform the operations of pulling out the needle or changing the medicine; S5. After completing the foregoing S1 to S4, the infusion control system is adjusted to the powered-off state, the capacitive liquid level sensor is disassembled from the outside of the infusion hose under the preset liquid medicine filter, and after external cleaning and disinfection, it is stored for the next use.

[0032] It should be noted that in the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps not listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The use of the words first, second, third, etc. is only for the purpose of convenience of expression and does not denote any order. These words can be understood as part of the name of the element.

[0033] In addition, it should be noted that in the description of this specification, the description of terms such as "one embodiment", "some embodiments", "embodiment", "example", "specific example" or "some examples" means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, without contradiction, those skilled in the art can combine and combine the different embodiments or examples described in this specification and the features of different embodiments or examples.

[0034] Although the preferred embodiments of the present invention have been described, those skilled in the art can make additional changes and modifications after learning the basic creative concepts. Therefore, the claims should be construed to cover the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention.

[0035] Obviously, those skilled in the art can make various modifications and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention should also cover these modifications and variations.

Claims

1. An infusion control system based on a capacitive liquid level sensor, characterized in that the capacitive liquid level sensor is wirelessly communicatively connected to a signal controller; the capacitive liquid level sensor is nested and adapted to the outside of the infusion hose on the lower side of the liquid medicine filter; the capacitive liquid level sensor is provided with: an induction detection module and a signal transmission module that are communicatively connected; For the induction detection module, a first voltage dividing resistor branch / a second voltage dividing resistor branch is connected to the positive input terminal / negative input terminal of the operational amplifier, and a variable coupling capacitor is connected in parallel between the two resistor branches; A bias capacitor is connected to the negative power supply terminal of the operational amplifier, a bias resistor is connected to the positive input terminal of the operational amplifier, and both ends of the feedback resistor are respectively connected to the negative input terminal and the output terminal of the operational amplifier; the output terminal of the operational amplifier is connected to a two-stage low-pass filter.

2. The infusion control system according to claim 1, characterized in that the first voltage dividing resistor branch is a structure in which a first voltage dividing resistor is connected in series with a second voltage dividing resistor; the second voltage dividing resistor branch is a structure in which a third voltage dividing resistor is connected in series with a fourth voltage dividing resistor; the variable coupling capacitor is a combination structure of a fixed electrode and a movable electrode; the low-pass filter is a structure in which a resistor is connected to a capacitor.

3. The infusion control system according to claim 1, characterized in that the first voltage dividing resistor branch, the second voltage dividing resistor branch and the variable coupling capacitor form a voltage dividing coupling circuit; the bias capacitor, the operational amplifier, the bias resistor and the feedback resistor form a differential input operational amplifier circuit; the two-stage low-pass filter forms a low-pass filter circuit.

4. The infusion control system according to claim 3, characterized in that the signal transmission module is composed of a current limiting resistor, a coupling capacitor, a collector load resistor, a first triode, a base bias resistor, a second triode, a field effect transistor, a first diode, a second diode, and a pull-down resistor.

5. The infusion control system according to claim 4, characterized in that the voltage dividing coupling circuit generates a change in capacitance value based on the change in the liquid level height of the liquid medicine inside the infusion hose on the lower side of the liquid medicine filter, so as to generate an electrode phase difference; the differential input operational amplifier circuit converts the electrode phase difference into a differential capacitance signal and amplifies the differential capacitance signal; the low-pass filter circuit removes high-frequency noise from the differential capacitance signal.

6. The infusion control system according to claim 5, characterized in that the first triode amplifies the differential capacitance signal in terms of current, the collector load resistor converts the differential capacitance signal into a voltage signal, and the second triode amplifies the voltage signal; the field effect transistor buffers and isolates the voltage signal; the first diode and the second diode cooperate to clamp and protect the voltage signal.

7. The infusion control system according to claim 1, characterized in that a monitoring display and an audible and visual alarm are respectively wirelessly communicatively connected to the signal controller; a control IC is provided inside the signal controller.

8. The infusion control system according to claim 7, characterized in that the control IC receives the voltage signal sent by the signal transmission module and judges whether there is liquid medicine in the infusion hose based on a preset judgment condition.

9. The infusion control system according to claim 8, characterized in that the preset judgment condition is: When the control IC does not continuously receive a voltage signal, there is still liquid medicine in the infusion hose; When the control IC continuously receives a voltage signal and the continuous reception duration reaches a preset duration, there is no liquid medicine in the infusion hose.

10. The infusion control system according to claim 8, wherein When it is determined that there is no liquid medicine in the infusion hose, while the sound and light alarm triggers a warning, the monitoring display shows the information of the infusion set corresponding to the current capacitive liquid level sensor.

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