Background
The insulin pump is an instrument which is controlled by a microcomputer to pump exogenous insulin into a human body timely, quantitatively and accurately. The device simulates the physiological mode that healthy pancreas of a human body secretes insulin, is internally provided with a drug storage device, continuously injects the insulin to the subcutaneous part of a user according to the dosage required by the human body through an infusion pipeline connected with the drug storage device, and keeps the blood sugar stability all day long so as to achieve the purpose of controlling diabetes. At present, insulin pumps are increasingly applied to clinical treatment of diabetes patients, and have good curative effect.
The design performance of an insulin pump is of utmost importance, especially its accuracy of administration. Too much or too little insulin injection is likely to result if the administration accuracy is low. The insulin pump is a fluid pump requiring high precision, and trace insulin errors easily cause irrecoverable consequences, particularly the fact that the human body hyperglycemia is directly caused by too little insulin of the human body, and then diabetic complications are caused; too much insulin in a human body can cause hypoglycemia and even shock or death of a patient; the safety of the insulin pump is more directly related to the life safety of the user.
At present, suspicious adverse events of medical instruments related to insulin pumps and infusion pipelines thereof are frequent, wherein the suspicious adverse events mainly comprise insensitive buttons of the insulin pumps, low medicament injection dosage, broken injection needles and the like. Through analysis, the clinical operation and nursing are not standard and are the main reasons of the occurrence of injury events, and the injury caused by unqualified product quality also needs to be noticed.
With the improvement of living standard and the change of life style of people, diabetes becomes a frequently encountered disease and a common disease and becomes the third killer after cardiovascular and cerebrovascular diseases and cancers in human beings. Insulin pumps are becoming more widely used and their manufacture and production is also "flowering" throughout the day.
However, as an important infusion therapy instrument, the Insulin pump is internationally established for interoperability of telemedicine Insulin pump devices (agents) and managers (such as mobile phones, Personal computers and Personal computers) and set-top boxes (STB) to realize plug and play, and ISO/IEEE 11073: (International organization for standardization-Personal Health provision) -Part 10419: Device specification-Insulin pump is not involved in an accuracy testing method of the Insulin pump. The medical industry standard of insulin pumps does not exist in China, related metrological verification rules or calibration specifications do not exist, and corresponding methods for calibrating instruments of the type are not published by related authoritative departments.
In view of the fact that the accuracy of the infusion flow of the insulin pump is crucial to the infusion safety and effectiveness in the using process, the method for calibrating the metering of the insulin pump is necessary and has important practical significance in order to avoid adverse events related to the insulin pump as much as possible, strengthen the post-mortem supervision on the quality of the insulin pump and ensure the accuracy and reliability of the data of the infusion quantity value of the insulin pump and the consistency of the traceability of the quantity value.
Disclosure of Invention
The purpose of the invention is as follows: aiming at the problems in the prior art, the invention aims to provide a metering calibration method for an insulin pump, so as to solve the detection of metering characteristics such as basal rate infusion indicating value error, large dose infusion indicating value error, infusion flow indicating value error and repeatability, infusion pressure safety and the like of the insulin pump, and solve the detection and traceability of real-time infusion flow indicating value error items of the insulin pump.
The technical scheme is as follows: an insulin pump metering calibration method comprises the following steps:
(1) constructing a calibration detection platform: the device comprises an electronic weighing module, a pressure testing module, a flow control module and a microcontroller module; the electronic weighing module is provided with a weighing sensor and used for measuring the weight of the insulin pump to be tested in different detection states, the pressure testing module is connected with the tail end of an insulin pump infusion pipeline and used for testing the pressure at the tail end of the insulin pump infusion pipeline, the flow control module is used for detecting the infusion flow of the insulin pump, and the microcontroller module is electrically connected with the electronic weighing module, the pressure testing module and the flow control module and used for receiving and processing an electronic weighing signal, a pressure testing signal and a flow signal, outputting a control signal and displaying result parameters;
(2) basal rate infusion indication error detection:
the drug storage device of the insulin pump to be tested is filled with distilled water, placed on a weighing sensor tray of the electronic weighing module, used for weighing the insulin pump to be tested and transmitting a data signal to the microprocessor module for storage; setting different basic infusion rates and injection times of the insulin pump, weighing the insulin pump again after injection is finished, calculating the mass difference before and after the mass difference is calculated by the microprocessor module, converting the mass difference into the volume of injected liquid, comparing the volume with the injection amount, verifying and calculating the error of the infusion indicating value of the basic rate, and displaying the error;
(3) large dose infusion indication error detection:
the drug storage device of the insulin pump to be tested is filled with distilled water, placed on a weighing sensor tray of the electronic weighing module, used for weighing the insulin pump to be tested and transmitting a data signal to the microprocessor module for storage; setting different basic infusion rates of the insulin pump for injection; weighing the insulin pump again after the injection is finished, calculating the unit amount of the insulin output by the microprocessor module, comparing and verifying the unit amount with the injection amount, continuously setting and performing infusion verification for at least 6 times, calculating the large-dose infusion indicating value error and displaying the large-dose infusion indicating value error;
(4) infusion flow indication error and repeatability:
the insulin pump medicine storage device to be detected is filled with distilled water and placed on a weighing sensor tray of an electronic weighing module, the insulin pump to be detected is weighed, and a data signal is transmitted to a microprocessor module to be stored as an input basic parameter; setting different basic infusion rates of the insulin pump for injection; after each injection is stable, the microcontroller module records the current instantaneous flow rate for at least 6 times, compares the current instantaneous flow rate with the flow rate set by the standard, calculates the error and repeatability of flow indication values, and obtains an accumulated flow value according to the flow rate and time;
(5) and (3) infusion pressure safety detection:
different basic infusion rates of the insulin pump are set, and when the pressure measured by the built-in pressure sensor of the pressure test module is greater than a preset threshold value, the tail end needle head of the insulin pump can provide enough infusion pressure, so that the requirement on the safety of the infusion pressure is met.
Specifically, in the safety detection of the infusion pressure, the preset threshold is 13.7 PSI.
Further, the method also comprises the following tracing steps: adopt the micro-flow syringe pump to pass through the hose connection insulin pump measurement calibrating device's tee bend input port opens the solenoid valve, and the micro-flow syringe pump is with certain velocity of flow injection liquid, weighs the weight of the interior liquid of collecting tank through electron weighing module, carries out flow control module's degree of accuracy and verifies.
Further, the method also comprises the detection steps of temperature alarm detection, medicine storage residue alarm and infusion blockage alarm.
Furthermore, the microcontroller module includes power management unit, communication conversion unit and liquid crystal touch screen unit, power management unit is used for installing the power supply of each module, communication conversion unit is used for accomplishing the wireless data communication of microcontroller module and uploads, liquid crystal touch screen unit includes a plurality of function button for reach measurement characteristic detection command down during man-machine interaction to show result parameter.
Furthermore, a temperature sensor is arranged on a pipeline where the flow control module is arranged and used for detecting the temperature change of the infusion liquid in real time, and the temperature sensor is electrically connected with the microcontroller module.
Preferably, the electronic weighing module, the flow control module, the temperature sensor and the pressure testing module are further respectively provided with a corresponding signal amplifying and filtering circuit and a corresponding signal conditioning circuit, and the signal amplifying and filtering circuit and the signal conditioning circuit are used for conditioning the output signal of the sensor and are electrically connected with the input end of the microcontroller module after being converted by the analog-to-digital conversion circuit.
Furthermore, the flow control module is provided with a nano-upgrading flow sensor.
Has the advantages that:
compared with the prior art, the invention has the following remarkable effects: the invention has higher detection precision, solves the detection of the metering characteristics of insulin pump basic rate infusion indicating value error, large dose infusion indicating value error, infusion flow indicating value error, repeatability, infusion pressure safety and the like; the detection and tracing of the real-time infusion flow indicating error item of the insulin pump are realized. And can be uptiled for pharmaceutical industry standards regarding insulin pumps, insulin pump metrological verification procedures or calibration specifications.
Detailed Description
The technical solution of the present invention will be further described in detail with reference to the following examples and accompanying drawings.
From the usual dose of insulin, 3mL of 300 units of insulin (300U), 3mL/300 ═ 10 μ L of volume per 1U of insulin, and the measurement of the metering characteristics of the insulin pump was carried out using distilled water instead of the insulin injection, and it was found that the density of water at ordinary temperature was 1g/cm3The volume of the infusion liquid can be converted by measuring the mass difference of the insulin pump before and after infusion through a weighing sensor with milligram-level precision, so that the injection amount of the insulin is further converted.
An insulin pump metering calibration method comprises the following steps:
as shown in fig. 2-3, an insulin pump metering calibration platform was constructed: the device comprises an electronic weighing module 1, a flow control module 2, a pressure testing module 3, a temperature sensor 4, a microcontroller module 5 and a liquid collecting tank 6. The microcontroller module 5 is electrically connected with the electronic weighing module 1, the flow control module 2, the pressure testing module 3 and the temperature sensor 4 and is responsible for the work of the whole system.
The electronic weighing module 1 is provided with a weighing sensor for measuring the weight of the insulin pump 7 to be measured in different detection states.
The pressure testing module 3 is provided with a pressure sensor for testing the pressure at the tail end of the infusion pipeline of the insulin pump 7 so as to ensure the safety of the infusion pressure of the insulin pump.
The flow control module 2 is provided with a nano-upgrading flow sensor for detecting the infusion flow of the insulin pump, and the nano-upgrading flow sensor preferably uses a Switzerland sensing SLG1430 series flow meter. Preferably, the pipeline of the flow control module 2 is provided with a temperature sensor 4 for detecting the temperature change of the infusion liquid in real time, so that a microenvironment required in flow detection is ensured, and the influence of the temperature change on the micro flow detection is reduced to the minimum.
The flow control module 2, the temperature sensor 4 and the pressure testing module 3 are provided with a corresponding signal amplifying and filtering circuit, a corresponding signal conditioning circuit and a corresponding analog-to-digital conversion circuit, and the signal amplifying and filtering circuit, the corresponding signal conditioning circuit and the corresponding analog-to-digital conversion circuit are used for conditioning output signals of the sensors and are electrically connected with the input end of the microcontroller module 5 after analog-to-digital conversion. The weighing sensor and the corresponding conditioning circuit of the electronic weighing module 1 are arranged in a rectangular casing, the bearing surface of the weighing sensor is provided with a tray,
furthermore, the microcontroller module is also provided with a power management unit, a communication conversion unit and a liquid crystal touch screen unit; the power supply management unit is responsible for completing 220V voltage transformation and supplying power to the whole system (comprising an electronic weighing module, a flow control module, a temperature sensor and a pressure testing module); the communication conversion unit is responsible for finishing wireless data communication uploading of the microcontroller module (a WIFI module can be selected); the liquid crystal touch screen unit can select corresponding function keys to issue measurement characteristic detection commands and display result parameters. Preferably, the microcontroller module adopts STM32F2 series high performance single chip microcomputer as the main control microprocessor.
In this embodiment, the infusion port of the insulin pump 7 to be tested is connected to a tee joint through a hose, and the other two ends of the tee joint are respectively connected with the electromagnetic valve 8 and the pressure testing module. The solenoid valve 8 is connected with the flow control module 2 through a hose, the hose pipelines of the solenoid valve 8 and the flow control module 2 are provided with the temperature sensor 4, and the other end of the flow sensor 2 discharges the waste liquid after the test into the liquid collecting tank 6 through the hose.
The microcontroller module 5 controls the valve switch of the electromagnetic valve 8, when the electromagnetic valve 8 is closed, the liquid of the infusion port of the insulin pump 7 to be tested directly flows into the pressure testing module 3 through the tee joint to detect the liquid pressure; when the solenoid valve 8 is opened, the liquid of the infusion port of the insulin pump 7 to be detected directly flows into the solenoid valve 8 through the tee joint, flows through the flow control module 2 through the hose provided with the temperature sensor 4, and detects the liquid flow.
As shown in fig. 1, the following main measurement characteristic detection flow is performed:
1. basal rate infusion indication error detection: and carrying out test operation in a normal-temperature closed experimental environment, clicking a basic rate infusion indicating value error detection function key of the liquid crystal touch screen unit of the microprocessor module, and entering the detection of the basic rate infusion indicating value error metering characteristic.
The drug storage device of the insulin pump to be tested is filled with distilled water, placed on a weighing sensor tray of the electronic weighing module, used for weighing the insulin pump to be tested and transmitting a data signal to the microprocessor module for storage; the basic infusion rate of the insulin pump is respectively set to be 0.05U/h, 17.5U/h and 35U/h, the injection time is respectively 24h, 6h and 2h, the insulin pump is weighed again after the injection is finished, the mass difference before and after the microprocessor module calculates and converts the mass difference into the volume of the injected liquid, the volume is divided by 10 mu L to obtain the amount of the injected insulin, the injected insulin is compared with the injection amount displayed by the equipment, the basic rate infusion indicating value error is calculated through verification, and the basic rate infusion indicating value error is displayed on the liquid crystal touch screen unit.
2. Large dose infusion indication error detection: and carrying out test operation in a normal-temperature closed experimental environment, clicking a large-dose infusion indicating value error detection function key of the liquid crystal touch screen unit of the microprocessor module, and entering detection of large-dose infusion indicating value error metering characteristics.
The drug storage device of the insulin pump to be tested is filled with distilled water, placed on a weighing sensor tray of the electronic weighing module, used for weighing the insulin pump to be tested and transmitting a data signal to the microprocessor module for storage; setting the basic infusion rate of the insulin pump to 10U/h and 25U/h respectively, and injecting; after the injection is finished, the insulin pump is weighed again, the microprocessor module calculates the unit amount of the injected insulin, the unit amount of the injected insulin is compared with the injection amount displayed by the equipment for verification, the unit amount of the injected insulin is continuously set and subjected to infusion verification for 6 times, the large-dose infusion indicating value error is calculated, and the large-dose infusion indicating value error is displayed on the liquid crystal touch screen unit.
3. Infusion flow indication error and repeatability: and (4) carrying out test operation in a normal-temperature closed experimental environment, clicking an infusion flow indicating error and repeatability detection function key of the liquid crystal touch screen unit of the microprocessor module, and entering the detection of the infusion flow indicating error and repeatability metering characteristics.
The infusion flow indicating error and repeatability metering characteristic detection means mainly tests the relationship between the flow rate of the insulin pump and other conditions (waveform, driving voltage, frequency, backpressure, pipe diameter and the like) and the stability and other problems of the insulin pump, utilizes a nanoliter flow sensor to measure the flow of liquid flowing out of an infusion outlet of the insulin pump in a period of time, and establishes the relationship between the flow rate and other parameters.
The insulin pump medicine storage device to be detected is filled with distilled water and placed on a weighing sensor tray of an electronic weighing module, the insulin pump to be detected is weighed, and a data signal is transmitted to a microprocessor module to be stored as an input basic parameter; setting the basic infusion rate of the insulin pump to 0.1U/h, 0.5U/h, 1U/h, 5U/h, 10U/h, 20U/h and 30U/h respectively, and injecting; after each injection is stable, the microcontroller module records the current instantaneous flow rate for 6 times, compares the instantaneous flow rate with the flow rate set by the standard, calculates the error and repeatability of flow indication values, and obtains an accumulated flow value according to the flow rate and time.
Tracing: the accuracy means of the developed flow control module is verified through a high-precision micro-flow injection pump, an electronic weighing module and a liquid collecting tank: the high-precision micro-flow injection pump is connected with a three-way input port of the insulin pump metering and calibrating device through a hose, an electromagnetic valve is opened, the high-precision micro-flow injection pump injects liquid at a certain flow speed, the weight of the liquid in the liquid collecting tank is weighed through the electronic weighing module, and the accuracy verification of the flow control module is carried out.
4. And (3) infusion pressure safety detection:
when the insulin pump is used for insulin injection, the insulin pump completes the insulin infusion through a needle embedded in subcutaneous tissues of the abdomen of a human body. Therefore, the pressure provided by the end of the needle is larger than the pressure of the subcutaneous tissue fluid of the human body, so as to ensure the normal injection and diffusion of the insulin. When the human body moves or the skin medium changes, the pressure at the tail end of the needle can change. Therefore, the infusion pressure safety detection means mainly tests that the pressure at the tail end of a water injection pipeline of the insulin pump is larger than 13.7PSI (94.46 kPa).
And (4) carrying out test operation in a normal-temperature closed experimental environment, clicking an infusion pressure safety detection function key of the liquid crystal touch screen unit of the microprocessor module, and entering the detection of the infusion pressure safety metering characteristic. The basic infusion rate of the insulin pump is respectively set to be 0.05U/h, 17.5U/h and 35U/h, when the pressure measured by the built-in pressure sensor of the pressure test module is larger than 13.7PSI (94.46kPa), the fact that the needle head at the tail end of the insulin pump can provide enough infusion pressure is shown, normal infusion can be performed under the conditions that human skin media change and the like, and the requirement on the safety of the infusion pressure is met.
5. Detection of other metering characteristics:
1) temperature alarm detection: as known from the chemical properties of insulin, insulin freezes at about 0 deg.C and deteriorates at high temperatures, generally not higher than 40 deg.C.
The combination device of the constant temperature box and the constant temperature circulating water tank provides a constant temperature environment for detecting the metering characteristics. The insulin pump to be detected is placed in the thermostat, the temperature of the thermostat is adjusted to enable the thermostat to be higher than the upper limit value or lower than the lower limit value of the insulin pump medicine storage device, and whether the insulin pump immediately triggers the alarm system with temperature abnormality information or not and the user is warned to take corresponding measures to achieve the purpose.
Since the constant temperature box and the constant temperature circulating water tank belong to mature technologies, the constant temperature box and the constant temperature circulating water tank are easy to obtain in the market and are not described here.
2) Medicine storage residue alarming: insulin pumps all have the detection function to remaining dose, mainly in order to prevent that the user from setting up the infusion volume after, insulin reserves are not enough, causes insulin infusion volume to reduce. The function can inform the user of preparing for replacing the medicine storage device in advance, and the occurrence of hyperglycemia is prevented.
Carry out test operation under the airtight experimental environment of normal atmospheric temperature, store up medicine and remain warning measurement characteristic detection means, when adjusting remaining dose in the medicine storage device and making the liquid measure reach certain unit to through the electron weighing module, the surplus dose of weighing is rechecked, whether can report to the police through the inspection instrument and indicate so that the user in time changes the medicine storage device and go on.
3) Transfusion blockage alarm: in order to ensure the safety of insulin pump infusion, the infusion process is ensured to be in a controllable and safe state.
The test operation is performed in a normal-temperature closed experimental environment, a blocking alarm threshold (pressure) specified by the manufacturer is selected, and if the blocking alarm threshold (pressure) can be selected, the minimum value is set. The insulin pump was started and the flow reached steady state, and the situation from the beginning of occlusion to the triggering of the occlusion alarm was observed.