This paper designs a drip velocity monitoring and alarming system, which not only realizes the prediction of total infusion time, the measurement and control of infusion velocity, but also realizes the alarm of infusion time, abnormal flow velocity, manual alarm of infusion accidents and remote monitoring and control of infusion information.
In clinical medicine, intravenous infusion has become the basic means to treat many diseases. With the development of science and technology and the improvement of information level, the digitalization and intellectualization of medical devices and equipment are the focus of current and future development of medical and health technology.
In the aspect of intravenous infusion, because of the requirement of accuracy and safety of infusion, a breakthrough has been sought in the intellectualization of intravenous infusion at home and abroad. The invention of infusion pump has solved this problem. It is a kind of medical equipment that can accurately control the number of infusion droplets or the flow rate of infusion, and ensure that the drug can be uniformly distributed, accurately and safely into the patient’s body. But because of the use of special consumables, the price is very expensive. Taking the transfusion pump of Berang in Germany as an example, the retail purchase price is about 20,000-25,000 yuan per unit and the batch bidding price is about 18,000-20,000 yuan per unit, so the popularization in hospitals is not optimistic. In the field of remote monitoring of infusion, there are also some attempts in China, but only gravity sensors are used to achieve the function of alarm at the patient end, and there is no good time prediction and speed control. Secondly, there is no third-party software attached to the hospital in the upper computer of the medical station, which can not be integrated with the hospital system, and mobile monitoring on the mobile phone.
The aspect is blank. Through the existing advanced precise measurement technology, Internet of Things technology and control technology at home and abroad, supplemented by some humanized parts, a drip velocity monitoring and control and alarm system is designed. On the one hand, thermostatic element the system can realize the remote real-time monitoring and control of patients’infusion information at the medical and nursing end; on the other hand, the accompanying staff can obtain infusion information through mobile phones, which greatly reduces the pressure of the accompanying staff, and provides a feasible step to improve the intelligence and digitalization of the medical system. The system is based on Arduino UNO R3 microcontroller, and consists of flow rate measurement and control, weighing and time prediction, communication, alarm and OLED display modules. The system is initialized after startup, and the velocity information is input by the medical staff. The velocity sensor can measure the drip velocity in real time, and the closed-loop control is carried out with the stepper motor. The high precision weighing sensor can measure the liquid quality in real time.
Combined with millis function, the infusion time can be predicted by the algorithm in real time.
Alarm can be given when abnormal flow rate, discomfort and infusion are about to be completed. Through ESP8266 wireless module, real-time data transmission is carried out between the medical and patient terminals, so that the medical staff can realize remote monitoring, and the family members can also obtain infusion information through mobile phones.
Arduino UNO R3 microcontroller is the nerve center of the system. It is mainly used to process the information of each sensor and to control the orderly work of each module of the system. The control microprocessor adopts ATmega328P-AU processor, which has strong application ability. The system is embedded with A/D conversion module. It has many interfaces, such as PWM interface, digital interface, analog input interface, serial communication interface and so on. It can carry many kinds of peripherals. It is very convenient to use and greatly improves the efficiency of hardware circuit. The data acquisition module consists of a velocity sensor and a weighing sensor, which are used to measure the flow rate of the infusion liquid and the quality of the weighing infusion bottle, including the bottle weight and the quality of the infusion bottle. Among them, the velocity sensor has three interfaces: VCC, GND and OUT. The OUT interface is connected with the 7 Digital interfaces of the controller, and the collected signals are output in high and low levels. The weighing sensor is connected with a 24-bit A/D conversion module HX711, and its measurement accuracy can reach 0.1g. HX711 has four interfaces: VCC, GND, SCK and DT. SCK and DT are connected with 5 and 6 Digital interfaces of MCU respectively to transmit the collected data. The schematic diagram is shown in Figure 2. Data processing module includes speed control module composed of stepping motor and mechanical pulley and alarm module. Stepper motor is a four-phase five-wire 5V motor driven by ULN2003.
It has the characteristics of high current gain, high working voltage, wide temperature range and strong load capacity. It is suitable for all kinds of high-speed and high-power drive systems. ULN2003 has VCC, GND and four digital input interfaces, corresponding to the 8-11 digital interface connected to MCU. The schematic diagram is shown in Figure 3. The data transmission module is composed of communication module, PC, mobile phone and so on.
It is used for remote transmission of infusion information. The communication module uses ESP8266 Wi-Fi module to realize bidirectional transmission of data between medical and patient terminals. The patient side uses ESP8266 Wi-Fi module, which transmits the infusion information to the cloud server for surveillance by doctors, nurses and family members. At the same time, the patient side and the medical side provide the function of two-way transmission of information, that is, the medical side can remotely control the infusion information of patients. The velocity sensor receives the transmission tube by infrared emission. Infrared light emitted by infrared LED is received by photosensitive diode through dropper.
When droplet drops down, the received signal will be weakened and pulse signal will be generated. The pulse signal will be sent to MCU through triode switch circuit. Number/time, expressed as “drip/minute”. Through the control of the positive and negative rotation of the stepping motor, the extrusion degree of the mechanical pulley on the transfusion pipe is changed to achieve the control of the transfusion flow rate. The stepping motor is used in conjunction with the flow sensor, and the closed-loop control method is adopted, so the control of the flow rate has relatively high accuracy. The weighing sensor pastes the resistance strain gauge on the elastic sensor and forms the bridge in an appropriate way, which converts the mass of the object into electrical signal. The weighing sensor measures the total mass of the infusion bottle, then subtracts the mass of the bottle input by manual keyboard or medical terminal, and obtains the net mass of the infusion bottle. By calculating and analyzing the information collected by the weighing sensor and the velocity sensor, we can predict the completion time of infusion. N1 is the current net mass of the infusion bottle and the infusion velocity. When the predicted remaining time of infusion is less than the preset value, the system sends out alarm information to the outside world (including remote alarm to the medical station); when the flow rate is lower or higher than the preset value of the system, the system automatically tries to increase or decrease the flow rate, and sends out alarm information to the outside world (including remote alarm to the medical station); the system also provides manual alarm. Button, when the patient in the process of infusion uncomfortable or other emergencies, you can contact the medical staff through this button. The monitoring and control of the medical and nursing end is mainly used to monitor and control the infusion information of patients remotely at the medical and nursing end. In the medical side, the upper computer or the function library of other monitoring software can be developed. The medical side can obtain the infusion information of patients through the cloud server (including the current quality of the liquid, the infusion speed and the expected time required for the completion of infusion), realize the monitoring of infusion information, or transmit the information to the micro-control through the cloud server. The device (information includes the quality of infusion bottle and the size of flow rate) controls infusion information, displays alarm information at the medical side (including the alarm of infusion time, the alarm of abnormal flow rate and the manual alarm information of infusion accidents), and numbers the patient’s room number and bed number, so as to realize the medical and nursing side. Monitoring and controlling infusion information of multiple patients. The patient’s family monitoring module is mainly used to provide patient’s infusion information to the patient’s family members remotely.
Family members of patients can obtain infusion information by means of micro-message scanning code, and monitor infusion information of patients in real time. This system effectively combines several functional units such as real-time monitoring and closed-loop control of flow rate, prediction and alarm of infusion time, which makes the infusion auxiliary equipment more intelligent and practical, and has lower cost, and is suitable for large-scale popularization and application. At the same time, through the application of “Internet ” technology, the real-time monitoring and intelligent management of patients’infusion situation in medical and nursing stations are realized, which improves the level of information service in hospitals, reduces the labor intensity of medical and nursing staff, and also reduces the psychological burden of accompanying staff.