CN108187186B

CN108187186B - Infusion monitoring and vital sign detection system

Info

Publication number: CN108187186B
Application number: CN201711442326.XA
Authority: CN
Inventors: 严如强; 周梦杰
Original assignee: Southeast University
Current assignee: Southeast University
Priority date: 2017-12-27
Filing date: 2017-12-27
Publication date: 2021-03-19
Anticipated expiration: 2037-12-27
Also published as: CN108187186A

Abstract

The invention discloses a transfusion monitoring and vital sign monitoring system, which comprises a dual-power supply module, a control unit, a liquid drop/liquid level detection module for detecting liquid drops and liquid levels, an electrocardio information acquisition module for acquiring electrocardio information, a pulse information acquisition module for acquiring pulse information, a blood pressure information acquisition module for acquiring blood pressure information, a storage module for storing acquired data, an alarm reminding module, an LCD display screen for displaying and displaying a monitoring value on a monitoring interface, a setting/function selection module for providing a user to autonomously select a corresponding monitoring function, setting parameters and an alarm threshold function, a wireless transmission module for transmitting information and set data to a data management computer for analysis, processing and fusion, and a dropping speed/blocking control module for controlling the dropping speed of transfusion and blocking control of transfusion termination. The invention can automatically monitor the infusion process and the main physiological parameters of the human body in real time, and is beneficial to reducing the working intensity of medical care personnel; and the health monitoring of the user can be realized.

Description

Infusion monitoring and vital sign detection system

Technical Field

The invention relates to the field of medical equipment and health monitoring, in particular to an infusion monitoring and vital sign monitoring system.

Background

Intravenous infusion is an important treatment means in medical care, is widely applied in clinic due to the characteristics of rapid drug administration, quick curative effect, small stimulation and the like, ensures the safety and effectiveness of the intravenous infusion process and is the main work content of a ward nurse, but the manual monitoring not only increases the working intensity of medical care personnel, but also is easy to cause nursing contradiction due to improper operation. In the process of infusion, the infusion cannot be monitored in the whole process, the mode of controlling the flow rate of the liquid medicine through the manual pulley is not accurate enough, and the manual regulation cannot meet the requirement. Therefore, the detection and the accurate control of the dropping speed in the infusion process are also the problems to be solved in the modern intelligent medical field.

The requirement of people on the quality of medical treatment and health is continuously improved due to the aggravation of aging degree and the continuous improvement of self-health care consciousness of people. Pulse, heart rate, electrocardio, blood pressure, etc. are the basic expressions of human vital activity, generally known as vital sign, and these activities are relatively stable in certain extent, indicate that human body probably has pathological change when it appears great change, as a health monitoring technique to the monitoring of vital sign, receive people gradually, especially middle-aged and old people's favor and attach attention gradually, vital sign monitoring facilities all have important status and better development prospect in every aspect.

The transfusion monitoring and vital sign monitoring system can comprehensively consider venous transfusion monitoring and vital sign monitoring, complete real-time monitoring and alarming on the dropping speed of liquid medicine, the residual amount of the liquid medicine, the liquid level and the like in the transfusion process, maintain the stable dropping speed through the control module of the stepping motor, and abandon the traditional method of controlling the dropping speed through a pulley; can simultaneously carry out real-time acquisition, detection and analysis processing on human vital signs (electrocardio, pulse, blood pressure and the like) in the infusion process, and has immeasurable significance to the current medical field. On one hand, the automatic monitoring and control of the infusion process greatly reduces the labor intensity of medical care personnel, improves the safety and reliability in the infusion process, and patients and family members can have good rest. On the other hand, the traditional vital sign detecting instrument has single measuring function, can only be used in specific application places such as hospitals or health centers, has larger volume and is not portable enough, and is not suitable for places such as field, family and community medical treatment. The invention designs an infusion monitoring and vital sign monitoring system to solve the problems.

Disclosure of Invention

The purpose of the invention is as follows: in order to solve the problems in the existing medical monitoring equipment and the venous transfusion process and realize the automatic monitoring of the dropping speed/liquid level and the simultaneous monitoring of a plurality of human body physiological parameters in the transfusion process, the invention provides a transfusion monitoring and vital sign monitoring system.

The technical scheme is as follows: the invention relates to a transfusion monitoring and vital sign monitoring system, which comprises a dual-power supply module, a control unit, a liquid drop/liquid level detection module, an electrocardio information acquisition module, a pulse information acquisition module, a blood pressure information acquisition module, a storage module, an alarm reminding module, an LCD display screen, a setting/function selection module, a wireless transmission module and a dropping speed/blocking control module, wherein the dual-power supply module is used for supplying power to the control unit;

the dual-power supply module is used for providing electric energy for the whole system; the liquid drop/liquid level detection module, the electrocardio information acquisition module, the pulse information acquisition module, the blood pressure information acquisition module, the storage module, the alarm reminding module, the LCD display screen, the setting/function selection module, the wireless transmission module and the dropping speed/blocking control module are all electrically connected with the control unit;

the liquid drop/liquid level detection module is used for detecting liquid drops and liquid levels; the electrocardio information acquisition module is used for acquiring electrocardio information; the pulse information acquisition module is used for acquiring pulse information; the blood pressure information acquisition module is used for acquiring blood pressure information; the storage module is used for storing the acquired data; the setting/function selection module can provide the functions of enabling a user to independently select corresponding monitoring functions and setting parameters and alarm thresholds, and can inform the user or medical personnel in time through the alarm reminding module when abnormal conditions occur; the LCD display module is used for displaying the monitoring interface and displaying the monitoring value; the dropping speed/blocking control module is used for controlling the dropping speed of the infusion and blocking control of the termination of the infusion; the wireless transmission module transmits various monitoring information and set data to the data management computer for analysis, processing and fusion.

In the liquid drop/liquid level detection module, a liquid drop/liquid level sensor is arranged on a Murphy's dropper in an intravenous infusion set, wherein the liquid drop sensor is positioned at the upper part of the Murphy's dropper, and the liquid level sensor is positioned at the lower bottom of the Murphy's dropper, can simultaneously monitor the drop speed and the liquid level and sends the drop speed and the liquid level to an LCD display screen for display; the dropping speed/blocking control module comprises a stepping motor, a stepping motor driving circuit and a sliding push rod, the stepping motor driving circuit is arranged on the infusion tube below the Murphy's dropper, and the stepping motor drives the screw rod to move forwards or backwards to extrude the infusion tube, so that the control of the dropping speed of the infusion and the blocking control of the termination of the infusion are realized.

Furthermore, the liquid drop sensor adopts an opposite infrared receiving and transmitting tube IR928-6C/PT928-6C, in the infusion process, according to the dropping condition of liquid drops, the output end of the receiving tube outputs square wave signals after being processed by a corresponding signal conditioning circuit and is electrically connected with the IO port of the control unit, the liquid level sensor adopts a DFRobot non-contact type liquid level sensor, and the output is electrically connected with the IO port of the control unit according to the existence of liquid on a horizontal line where the liquid level sensor is located and pulse signals can be output.

The electrocardiogram information acquisition module comprises a guide electrode, lead wires, an electrocardiogram sensor and a signal conditioning circuit, wherein the three lead wires of the electrocardiogram sensor are connected with the guide electrode and are respectively placed on the right arm, the left arm and the left leg of a tested person in a pressurization right upper limb single-pole lead mode; the pulse information acquisition module comprises a pulse sensor and a signal conditioning circuit, wherein the pulse sensor is placed at the radial artery of the wrist of the left hand or the right hand of a human body; the blood pressure information acquisition module comprises a cuff, an inflator pump and a control circuit, wherein the cuff is placed on the upper arm of a human body, and the distance between the lower edge of the cuff and the cross grain of the elbow is 2-3 cm.

Furthermore, the electrocardio sensor adopts an HKD-10A analog quantity electrocardio sensor, and an Ag/AgCl electrode is taken as a guide electrode and is attached to the corresponding position of the human body; the pulse sensor adopts an HK-2000B type pulse sensor, and senses pressure change through a PVDF piezoelectric film element; the blood pressure sensor module adopts a SUPERNIBP200A blood pressure measuring module and is communicated with the control unit through a UART1 serial port.

The storage module adopts an SD card storage mechanism and is used for storing a dropping speed set value, total liquid volume, residual liquid volume, real-time dropping speed, electrocardio, pulse and blood pressure monitoring data, and the SD card is communicated with the control unit through an SPI serial port; the alarm module comprises a buzzer and an NPN triode which are electrically connected with the control unit; the LCD display screen is communicated with the control unit through SCI to realize the display of various monitoring information and reminding information; the setting/function selection key module is electrically connected with the control unit by adopting keys, and the functions of setting each monitoring threshold and selecting functions are realized by using the inquiry mode detection keys.

The dual-power supply module adopts a power adapter, the output of the power adapter is connected with the input of the power management chip and is connected with the rechargeable lithium battery through the peripheral resistor capacitor and the field effect tube, and the output of the power adapter and the output of the lithium battery realize the automatic switching of the power supply of the adapter and the power supply of the lithium battery through two diodes.

Wherein, the monitoring system comprises a real-time monitoring control thread of the infusion process and comprises the following steps:

(1) setting the dropping speed, the total amount of the liquid medicine and the alarm reminding amount of the residual liquid medicine, sending a reset signal to a dropping speed/blocking control module, and interrupting the counting of the opened liquid drops and interrupting the liquid level;

(2) the watchdog timer is interrupted, and starting signals are sent to the liquid drop sensor and the liquid level sensor;

(3) when the timer times out, calculating the actual dropping speed and the residual liquid medicine amount;

(4) and (3) comparing the actual dropping speed and the residual liquid medicine amount with set values respectively, controlling a motor to adjust the dropping speed, storing and transmitting data, alarming in abnormal conditions, controlling the motor to block transfusion and terminate transfusion if the liquid level is low and the interruption is triggered, and otherwise, turning to the step (2).

The monitoring system comprises an electrocardio information acquisition processing thread and a pulse information acquisition processing thread, and comprises the following steps:

(1) reading a function setting command or receiving an acquisition command of a data management computer, and starting a timerA timer for interruption;

(2) if the timer counts and overflows, executing an interrupt service program and starting ADC sampling;

(3) and after the ADC sampling is finished, reading and storing the data, sending the data to an LCD display screen for display and actively transmitting the data to a data management computer, and otherwise, continuously waiting for the ADC to finish sampling.

The monitoring system comprises a blood pressure information acquisition processing thread and comprises the following steps:

(1) reading a function setting command or receiving an acquisition command of a data management computer, and sending a blood pressure detection instruction to a blood pressure detection module by a serial port UART 1;

(2) the blood pressure measuring module starts to detect the blood pressure value, if a measurement termination command is received, the measurement is terminated, and the step (1) is carried out;

(3) and reading the blood pressure measured value, storing the data, sending the data to an LCD display screen for display, and actively transmitting the data to a data management computer.

Has the advantages that: compared with the prior art, the infusion monitoring system can automatically monitor the dropping speed and the liquid level in the infusion process, relieves the working intensity of medical staff, enables patients and family members to have good rest, can monitor human vital signs (physiological parameters) while infusing, can be independently used as a vital sign monitor, introduces a wireless transmission and computer management data mode, provides precious physiological parameter historical data for self health management, provides data basis for diagnosis of doctors, simultaneously is used for providing electric energy for the whole system and can cope with sudden power failure and other emergencies, meets the use requirements in various places such as community medical treatment, families and outdoors and the like, relieves the contradiction between supply and demand to a certain extent, and has potential economic and social values. In addition, the invention can automatically monitor the infusion process and the main physiological parameters of the human body in real time, thereby being beneficial to reducing the working intensity of medical personnel; on the other hand, the health monitoring of the user can be realized, precious physiological parameter historical data are provided for the health management of the user, and the method has certain economic value.

Drawings

FIG. 1 is a circuit framework of the infusion monitoring and vital signs monitoring system of the present invention;

FIG. 2 is a drop/level sensor and drop rate/block control mounting layout of the present invention;

FIG. 3 is a layout diagram of the ECG, pulse sensor and blood pressure detection module of the present invention;

FIG. 4 is a signal conditioning circuit connection diagram of the present invention;

FIG. 5 is a connection diagram of a dual power supply module of the present invention;

fig. 6 is a flowchart of the main process of MSP430F149 according to the present invention.

Detailed Description

The technical solution of the present invention will be described in detail below with reference to the accompanying drawings.

The invention discloses an infusion monitoring and vital sign monitoring system which comprises a dual-power-supply power supply module, an MSP430 chip main control module, an infusion monitoring module, a vital sign monitoring module, a setting/function selection module, an LCD display module and a wireless transmission module. Wherein, monitoring system can realize four ways work according to setting for the demand: a, monitoring and controlling the dripping speed/liquid level in real time in the infusion process; b, monitoring electrocardio information of the human body; c, monitoring human pulse information; and D, monitoring the blood pressure information of the human body. In addition, the dual-power supply module is used for providing electric energy for the whole system and can deal with sudden power failure and other emergency situations, and the requirements of use in various places such as community medical treatment, families, outdoors and the like are met; the setting/function selection module can provide the functions of the user for independently selecting the corresponding monitoring function and setting parameters and alarm threshold values, and can inform the user or medical personnel in time through the alarm reminding module when abnormal conditions occur so as to take corresponding measures in time; the LCD display module is used for displaying the monitoring interface and displaying the monitoring value; the wireless transmission module transmits information such as infusion information, vital sign (electrocardio, pulse and blood pressure) information, set data and the like to the data management computer for analysis, processing and fusion so that medical personnel can evaluate the health condition of a user.

The system can realize real-time monitoring and monitoring of human body vital signs (or called human body physiological parameters) in the infusion process, corresponding functions can be automatically selected through the setting/function selection module, monitored information can be displayed on the LCD display screen in real time, automatic alarming can be realized through the alarming and reminding module when abnormal conditions occur, and simultaneously all monitored information is transmitted to the data management computer in a wireless mode, so that medical personnel can observe, record and analyze, the MSP430F149 is used as a main control chip (namely a control unit), and the orderly work of all modules is coordinated.

The content comprises the following steps:

a, a circuit frame of a transfusion monitoring and vital sign monitoring system consists of a dual-power supply module, an MSP430F149 processing chip, a liquid drop/liquid level sensor, a drop speed/blocking control stepping motor, an electrocardio sensor, a pulse sensor, a blood pressure sensor module, a storage module, an alarm module, an LCD display screen, a setting/function selection key module and a wireless transmission module;

b, the software main thread of the transfusion monitoring and vital sign monitoring system comprises: the infusion control method comprises a real-time monitoring control thread, a blood pressure information acquisition and processing thread, an electrocardio information acquisition and processing thread and a pulse information acquisition and processing thread in the infusion process.

The system comprises a dual-power supply module, a control unit, a liquid drop/liquid level detection module, an electrocardio information acquisition module, a pulse information acquisition module, a blood pressure information acquisition module, a storage module, an alarm reminding module, an LCD display screen, a setting/function selection module, a wireless transmission module and a dropping speed/blocking control module. The dual-power supply module is used for providing electric energy for the whole system; the liquid drop/liquid level detection module, the electrocardio information acquisition module, the pulse information acquisition module, the blood pressure information acquisition module, the storage module, the alarm reminding module, the LCD display screen, the setting/function selection module, the wireless transmission module and the dropping speed/blocking control module are all electrically connected with the control unit.

The liquid drop/liquid level detection module is used for detecting liquid drops and liquid levels; the electrocardio information acquisition module is used for acquiring electrocardio information; the pulse information acquisition module is used for acquiring pulse information; the blood pressure information acquisition module is used for acquiring blood pressure information; the storage module is used for storing the acquired data; the setting/function selection module can provide the functions of the user for independently selecting the corresponding monitoring function and setting the alarm threshold value, and the user or medical personnel can be informed in time through the alarm reminding module when the abnormal condition occurs; the LCD display module is used for displaying the monitoring interface and displaying the monitoring value; the dropping speed/blocking control module is used for controlling the dropping speed of the infusion and blocking control of the termination of the infusion; the wireless transmission module transmits the information and the set data to a data management computer for analysis, processing and fusion.

As shown in fig. 1, the circuit frame of the infusion monitoring and vital sign monitoring system is composed of a dual power supply module, an MSP430F149 main control chip, a droplet/liquid level detection module, a droplet speed/blocking control module, an electrocardiogram information acquisition module, a pulse information acquisition module, a blood pressure information acquisition module, an SD card storage module, an alarm reminding module, an LCD display screen, a setting/function selection module, and a wireless transmission module. As can be seen from fig. 1, the liquid drop/liquid level detection module, the electrocardiogram information acquisition module, the pulse information acquisition module, the setting/function selection module, the blood pressure information acquisition module, the LCD display screen, the wireless transmission module, the SD card storage module, the alarm reminding module and the stepping motor (the dropping speed/blocking control module) are electrically connected with the control unit (MSP430F149 main control chip).

The dropping speed/blocking control module adopts a stepping motor to drive a push rod to move forwards or backwards to extrude the infusion tube, so that the aims of dropping speed control and infusion stopping blocking are fulfilled; the storage module adopts an SD card storage mode, the SD card and the MSP430F149 processing chip realize data storage and reading through SPI serial port communication, and a port used by the SPI is a P5 port of the control unit; the wireless transmission module is connected with the control unit by a GPRS module, bidirectional transmission of data between the control unit and the data management computer is realized in a UART0 serial port communication mode, and UART0 communication occupies P3.4 and P3.5 pins of the control unit.

The setting/function selection module adopts a program scanning key mode to realize parameter setting and detection function selection, and a plurality of keys form a matrix keyboard form to be connected with the control unit and occupy a P2 port of the control unit; the LCD display screen module is connected with the control unit in an SCI communication mode to realize data display, and occupies a P3 port of the control unit; the alarm reminding module consists of a triode Q8050 and a buzzer, the base of the triode is connected with a P4.7 pin of the control unit, and the control unit controls the buzzer to sound through outputting high and low levels, so that the purpose of alarm reminding is achieved.

As shown in fig. 2, the installation layout of the droplet/liquid level sensor and the droplet speed/blocking control module of the droplet/liquid level detection module, for safety, in order to prevent contamination of the liquid medicine, neither the detection sensor (droplet/liquid level sensor) nor the droplet speed control unit (droplet speed/blocking control module) can directly contact with the liquid medicine, as can be seen from fig. 2, the droplet and liquid level sensor are installed on the murphy type dropper in the intravenous infusion set through a fixing device, wherein the droplet sensor is located at the upper part 1/3 of the murphy dropper, i.e. it is necessary to ensure that the droplet is located above the infrared light beam formed by the emitting end and the receiving end of the droplet sensor before the droplet is dropped, so as to prevent the droplet from interfering with the sensor response before the droplet is converged and. The liquid level sensor is located at the lower bottom of the Murphy's dropper, as shown in FIG. 2, and it is required to ensure that the liquid in the dropper is higher than the upper part of the probe of the liquid level sensor in the vertical direction. The dropping speed/blocking control module (comprising a stepping motor) is arranged at a position 5cm away from the lower part of the Murphy's dropper through a fixing device, the infusion tube is clamped between the baffle and the push rod, and the stepping motor drives the push rod to move forwards or backwards to extrude the infusion tube, so that the control of the infusion dropping speed and the blocking control of the infusion termination are realized.

The liquid drop sensor adopts a correlation type infrared receiving and transmitting tube IR928-6C/PT928-6C, the IR928-6C is a high-intensity light emitting diode, can transmit infrared rays through a plastic infusion dropper, has high radiation intensity and peak wavelength of 940nm, is driven by a driving circuit to emit light, forms a light path with a receiving tube, and has the principle of detecting liquid drops that: in the infusion process, when liquid drops fall to shield the light beam, the light signal received by the receiving tube is weak due to energy attenuation, and the receiving tube is not conducted enough; when the liquid drops do not block the light beam, the receiving tube receives the light signal with enough intensity, and the receiving tube is conducted. According to the dropping condition of the liquid drops, the output end of the receiving tube outputs square wave signals after being processed by a corresponding shaping circuit (signal conditioning circuit), and the square wave signals are electrically connected with an IO port of the control unit, and the control unit counts the liquid drops by capturing the rising edge or the falling edge of the square wave signals. The liquid level sensor adopts a DFRobot non-contact liquid level sensor which is also driven (powered) by a driving circuit, and the working principle is as follows: when liquid is in the transverse and longitudinal areas where the probes are located, high level is output, otherwise, low level is output. When the transfusion is finished, the liquid medicine in the Murphy's dropper is continuously reduced, and the liquid level is lower than the detection area of the probe, the liquid level sensor outputs a level jump signal, and the level jump signal is input into the control unit after being shaped by the shaping circuit.

The shaping circuit is composed of a voltage comparator LM393 and a filter capacitor, a square wave signal is output from the receiving end of the liquid drop sensor through the shaping circuit, and a jump signal is output from the liquid level sensor through the shaping circuit. The dripping speed/blocking control module is composed of a stepping motor, a stepping motor driving circuit, a sliding push rod and the like. The step motor driving circuit mainly comprises an ULN2003 driving chip, a high-voltage-resistance and high-current NPN Darlington tube is integrated in the step motor driving circuit, the step motor can be driven only by 5V voltage power supply, the step motor can automatically adjust the dropping speed and achieve the purposes of abnormal infusion and stopping blocked infusion by driving a sliding push rod to move forward or backward to extrude an infusion tube, an output pin of the ULN2003 driving chip is connected with the step motor in a two-phase four-wire system mode, an input pin of the ULN2003 driving chip is connected with a control unit, and the input pin of the ULN2003 driving chip occupies a P4 port. The model of the stepping motor is 24BYJ-48, and the parameters are as follows: the step angle is 5.625 degrees/64 degrees, the speed reduction ratio is 1:64, 4 phases and 5V are supplied. The control unit can control the rotation angle of the motor by controlling the output pulse number, and the rotation angle formula is as follows:

ω＝θ_N×N (1)；

wherein, theta_NIn the dripping speed control period, the difference between the actual dripping speed and the set dripping speed is obtained to obtain Delta T, and the sectional PID is adopted to control the rotation degree of the stepping motor so as to control the forward or backward distance of the sliding push rod (namely the degree of extruding the infusion tube) to realize the automatic regulation and control of the dripping speed. The propulsion or retraction distance calculation is as follows:

S＝K_i×△T×θ_N (2)；

wherein S is the distance (amplitude) of advance or retreat of the sliding push rod, K_iThe scale factor is segmented according to the size of Delta T, and the larger the Delta T is, the corresponding K is_iThe dripping speed is larger, and the dripping speed is smaller if the dripping speed is larger, namely the difference between the actual dripping speed and the set dripping speed is large, the stepping motor can rapidly adjust the dripping speed; when the difference is small, the stepping motor slowly finely adjusts the dripping speed to a set value, so as to achieve the purpose of sectional PID adjustment of the dripping speed.

As shown in figure 3, the layout of the electrocardio-pulse sensor and the blood pressure detection module, the electrocardio-information acquisition module comprises an electrocardio sensor, a guide electrode, a lead wire and a signal conditioning circuit, wherein the three lead wires of the electrocardio sensor are respectively connected with the guide electrode, an Ag/AgCl electrode is adopted as the guide electrode, 75 percent medical alcohol is needed to disinfect the skin surface of a user before use so as to reduce the contact noise between the electrode and the skin, improve the pickup performance of the guide electrode and obtain high-quality electrocardio signal waveforms, the guide electrode is respectively placed at a position (RA) 3cm above the inner wrist joint of the right arm, a position (LA) 3cm above the inner wrist joint of the left arm and a position (LL) 7cm above the inner ankle of the tibia of the lower limb of the left leg in a pressurizing mode as shown in figure 3, the output of the electrocardio sensor is connected with the input of the signal conditioning circuit, after signal conditioning, the signals are input into a control unit (MSP430F149 main control chip) for ADC acquisition. The pulse information acquisition module comprises a pulse sensor and a signal conditioning circuit, wherein the pulse sensor is placed at the radial artery of the wrist of the left hand or the right hand of a human body, and the output is conditioned by the signal conditioning circuit and then input to the control unit for ADC sampling. The blood pressure information acquisition module comprises a cuff, an inflator pump and a control circuit, the cuff is placed on the upper arm of a human body, the lower edge of the cuff is 2-3cm away from the cross grain of the elbow, the output of the cuff is connected with a UART1 serial port of the control unit, the control unit only needs to send an instruction to the blood pressure information acquisition module, the automatic acquisition of the blood pressure information can be realized, and the blood pressure information is transmitted back to the control unit after the acquisition.

The main frequency spectrum range of an Electrocardiosignal (ECG) is 0.05-100Hz, 90% of ECG frequency spectrum energy is mainly concentrated between 0.25-35 Hz, and the amplitude range is about 0-4 mV, so the ECG signal belongs to a low-frequency weak signal. In the specific implementation mode, the electrocardio sensor adopts an HKD-10A analog quantity electrocardio sensor, and the technical parameters are as follows: the signal amplification factor is 475 times; the common mode rejection ratio CMRR was 65 dB; input impedance of 10⁶M omega; a high-pass filter and a low-pass filter are integrated inside to extract a main energy frequency band of an Electrocardiosignal (ECG), namely 0.05-100 Hz; the internal 50Hz power frequency trap circuit can effectively filter 50Hz power frequency signals. The pulse sensor adopts an HK-2000B type pulse sensor, and pressure change caused by pulsation is sensed through a PVDF piezoelectric film element, so that pulse signal measurement is realized.

The blood pressure sensor module adopts a SUPERNIBP200A blood pressure measuring module, the blood pressure sensor module and the MSP430F149 main control chip realize communication through a UART1 serial port, the communication is in a TTL level mode, the baud rate is 4800bps, and the definition of each pin of the module is shown in the following table:

a serial port communication protocol is established between the blood pressure information acquisition module and the control unit, and the format, the instruction and the return data packet of communication are specified, specifically: start bit +8 bit data bit +1 bit stop bit, no check bit. The control unit sends a measurement command which comprises a measurement mode, a measurement cycle time, a measurement mode, pre-charging pressure value setting, gas path gas leakage detection and the like. For example, the measurement command "0230313B 3B 443703" indicates that automatic blood pressure measurement is turned on; a command "0230373B 3B 443903" indicates an automatic measurement mode set to a period of 60 minutes, or the like; if the module receives a command "X" at any time, it means that the measurement is terminated. The specific blood pressure measuring process comprises the following steps: A) the control unit sends a measurement command; B) the blood pressure information acquisition module receives the command, inflates the cuff and automatically detects the pressure in the cuff; C) when the pressure reaches a set value, the cuff is deflated and the pressure in the cuff is continuously detected until the pressure is 0; D) the blood pressure information acquisition module sends the measurement result to the control unit.

As shown in fig. 3 and 4, it can be seen from fig. 3 that the outputs of the pulse and the ecg sensors are processed by the signal conditioning circuit before being sampled by the control unit. Referring to fig. 4, the specific conditioning steps of the signal are: A) the output value of the sensor is subjected to inversion processing by a voltage inversion proportional circuit consisting of LM358, and a forward voltage value is output; B) a level lifting circuit composed of LM358 lifts the voltage in the step A) to enable the signal after level lifting to meet the voltage range which is met by the ADC acquisition of a control unit (MSP430F149 main control chip); C) the control unit performs ADC acquisition.

In the specific implementation process, the electrocardio detection adopts a pressurized monopole right upper limb lead mode, the amplitude voltage range of the electrocardio waveform obtained by the HKD-10 electrocardio sensor is about-0.8-0V and exhibits inversion, namely, an ECG signal presents an inverted image, the power supply voltage of the control unit is 3.3V, and the voltage range acquired by the ADC is 0-3.3V, so that the output signal of the sensor needs to be subjected to inversion and level lifting conditioning before A/D conversion of an analog quantity electrocardiosignal. In fig. 4, after the signal is conditioned by the first-stage inverting proportional circuit, the output amplitude range is 0.0-1.6V, and then the output amplitude range is 0.8-2.4V by the second-stage level-lifting circuit, so that the voltage range requirement of the control unit for ADC acquisition is met. Similar to an electrocardio sensor, the amplitude of the original output voltage of the pulse sensor is about-0.2-1V, and meanwhile, the A/D conversion can be carried out after the signal conditioning circuit is used for processing, and in the specific implementation process, the output range after the conditioning circuit is used for conditioning is as follows: 0.4-2.8V, and the voltage range requirement of ADC acquisition by the control unit is met.

As shown in fig. 1 and 5, the transfusion monitoring and vital sign monitoring system adopts a dual power supply module to provide electric energy for the whole system. As can be seen from fig. 5, the dual power supply module is composed of a power adapter, a MAX1873 lithium battery charging control module, a rechargeable lithium battery, and an output switching module. The power adapter plug is inserted into 220V alternating current commercial power, stable direct current 8.4V is output, current 800mA is output, the output of the power adapter plug is connected with the input of a power management chip MAX1873 on one hand, the output of the power adapter plug is connected with a rechargeable lithium battery through a peripheral resistor capacitor and a field effect transistor NDS8435A, meanwhile, a control unit periodically performs ADC acquisition on the voltage of the lithium battery and monitors the electric quantity, the MAX1873 realizes smooth switching control on the voltage and the charging current of the lithium battery through two control cycles of current and voltage, and realizes current regulation on an input source through the other control cycle; the output of the power adapter is connected to the output switching module, and the output of the rechargeable lithium battery is also connected to the output switching module, wherein the output switching module is composed of two diodes. The principle of dual power supply switching is as follows: when commercial power is available, the output voltage of the power adapter is higher than the voltage of the rechargeable lithium battery, and the output switching module only allows the power adapter to output power to supply power for the whole system; when power failure or other conditions without mains supply occur, the voltage of the rechargeable lithium battery is higher than the output voltage of the power adapter (no output of the power adapter exists at the moment), and the output switching module only allows the rechargeable lithium battery to provide electric energy for the whole system.

As shown in fig. 6, the main software thread for infusion monitoring and vital sign monitoring system mainly includes the following aspects: the automatic monitoring, blood pressure information acquisition and processing, electrocardio and pulse information acquisition and processing and the like of the infusion process can be seen from figure 6, and the main flow steps are as follows:

(1) initialization: the method comprises the steps of initializing a system clock, initializing each port of a control unit, initializing serial port communication, initializing an ADC (analog-to-digital converter), initializing a timer and the like, and starting total interruption;

in the initialization process, the main control unit ports used are described as follows:

(2) the LCD display screen displays necessary information, such as a bed number, an instrument number and the like, inquires a key setting command and waits for a receiving command;

(3) and (3) matching the addresses, if the addresses are not the local addresses, returning to continue inquiring, if the addresses are the local addresses, indicating that the addresses are successfully matched, and entering three main branch processes according to setting after the addresses are successfully matched.

The real-time monitoring control thread of the infusion process comprises the following implementation steps:

(1) parameter setting

Setting the dropping speed, the total amount of the liquid medicine and the alarm reminding amount of the residual liquid medicine (the default dropping speed is 50 drops/minute, the total amount of the liquid medicine in each bottle is 500ml, and the alarm reminding amount of the residual liquid medicine is 20ml), resetting the dropping speed/blocking control module of the stepping motor, and opening P1 to stop the counting of the liquid drops and stop the low liquid level.

(2) WDT ON timer interrupt

The watchdog timer is interrupted and the droplet sensor and the liquid level sensor start to work.

(3) Determining timing time

When the timer times out for 6s, calculating the actual dropping speed: v is 10 x Δ T, where Δ T is the number of drops in 6s, and the remaining amount of liquid medicine is calculated: v_res＝V_sum-0.05 x C, wherein V_sumFor the total amount of the liquid medicine set in the step A, 0.05 is an infusion coefficient (determined by an infusion set), namely the volume of each drop of liquid is 0.05ml, and C is the monitored total amount of the drops; if the timing time is not up, returningA query is made.

(4) The actual dropping speed, the residual liquid medicine amount and the like are respectively compared with set values, the motor is controlled to adjust the dropping speed, data are stored and transmitted, abnormal conditions are alarmed, if the liquid level is low and the interruption is triggered, the motor is controlled to block transfusion, and the transfusion is stopped.

The electrocardio/pulse information detection processing thread comprises the implementation steps of:

(1) turn on TimerA timer interrupt

Reading a function setting command or receiving an acquisition command of a data management computer, and starting a timerA timer for interruption;

(2) judging whether the count overflows

If the timer counts and overflows, executing an interrupt service program, and starting ADC sampling in the interrupt service program; otherwise, counting by the query timer;

In the specific implementation process, 2.5V is set as an internal reference voltage when an ADC digital-to-analog converter is initialized, and a sequence single sampling mode is adopted, so that the frequencies of electrocardiosignals and pulse signals are mainly concentrated in the range of 0.05-100Hz, and the sampling frequency of the ADC is set to be 200Hz when a timer A is initialized according to the Nyquist sampling theorem. In the electrocardio/pulse detection thread, the execution process in the timer interrupt service program is as follows: entering a timer A interrupt; starting ADC conversion; waiting for the completion of conversion, reading conversion data if the conversion is completed, and storing the conversion data into a one-dimensional array ECG [128] if the conversion is completed; setting a flag bit to count the acquired electrocardio-data, and when the count reaches 128, opening up an FFT transformation line to perform 128-point FFT transformation on the data in the array to obtain the frequency spectrum of an electrocardio-signal (ECG) signal; calculating a heart rate value according to the frequency spectrum, if the heart rate value is pulse data, recording the pulse beating times in unit time by threshold value comparison, and calculating the pulse rate; and storing and transmitting the data to the data management computer.

The blood pressure information acquisition and processing thread comprises the following implementation steps:

(2) the blood pressure information acquisition module starts to detect the blood pressure value, if a measurement termination command is received, the measurement is terminated, and the step A is carried out;

The wireless transmission module realizes the communication between the control unit and the data management computer, and the transmission module adopts a GPRS module and is connected with UART0 of the control unit. The UART0 serial port is initialized, the data format is set to 8 bit data bit, 1 bit stop bit, no check bit, the baud rate is 9600 bps. The format of the communication command (issuing command) issued by the data management computer to the monitoring system is formulated as follows:

wherein, the preamble is a flag of the data frame, here a fixed value of 0 xDA; the address code comprises a source address and a destination address, the length of the two bytes is the length of the source address, the source address is the address of the data management computer, and the destination address is the address of each monitoring system; the command code comprises a monitoring instruction to be executed by the monitoring system, and is 1 byte long, for example, 30H is used for monitoring transfusion, 31H is used for collecting electrocardio, 32H is used for collecting pulse, 33H is used for collecting blood pressure and the like; the reserved segment is used for command expansion; the check code is the check code of each frame of data. The format of the data frame transmitted from the monitoring system to the data management computer is formulated as follows:

the monitoring system periodically uploads data in the working process, wherein the definitions of a lead code, an address code, a command code and a check code are the same as those of an issued instruction, and the difference is that the lead code is set to be 0 xDD; wherein the data segment format is:

byte(s)	1-6	7-16	17-29	20-22	23-25	26-27
							Description of the invention	Time	Infusion information	Electrocardiographic information	Pulse information	Blood pressure information	Electric quantity

The infusion information comprises a bed number, a dropping speed, an infusion total amount, a reminding amount, an actual dropping speed, a residual amount and the like. In addition, if the function is not started, the corresponding monitoring values are all set to be 0, and if only the electrocardiograph detection is carried out, the information of infusion, pulse and blood pressure is all 0. The SD is also stored in this format.

Claims

1. The utility model provides an infusion control and vital sign monitoring system which characterized in that: the system comprises a dual-power supply module, a control unit, a liquid drop/liquid level detection module, an electrocardio information acquisition module, a pulse information acquisition module, a blood pressure information acquisition module, a storage module, an alarm reminding module, an LCD display screen, a setting/function selection module, a wireless transmission module and a dropping speed/blocking control module;

the liquid drop/liquid level detection module is used for detecting liquid drops and liquid levels; the electrocardio information acquisition module is used for acquiring electrocardio information; the pulse information acquisition module is used for acquiring pulse information; the blood pressure information acquisition module is used for acquiring blood pressure information; the storage module is used for storing the acquired data; the setting/function selection module can provide the functions of enabling a user to independently select corresponding monitoring functions and setting parameters and alarm thresholds, and can inform the user or medical personnel in time through the alarm reminding module when abnormal conditions occur; the LCD display module is used for displaying the monitoring interface and displaying the monitoring value; the dropping speed/blocking control module is used for controlling the dropping speed of the infusion and blocking control of the termination of the infusion; the wireless transmission module transmits various monitoring information and set data to the data management computer for analysis, processing and fusion;

in the liquid drop/liquid level detection module, a liquid drop/liquid level sensor is arranged on a Murphy's dropper in an intravenous infusion set, wherein the liquid drop sensor is positioned at the upper part of the Murphy's dropper, and the liquid level sensor is positioned at the lower bottom of the Murphy's dropper, can simultaneously monitor the drop speed and the liquid level and sends the drop speed and the liquid level to an LCD display screen for display; the drip speed/blocking control module comprises a stepping motor, a stepping motor driving circuit and a sliding push rod, and is arranged on the infusion tube at the lower part of the Murphy's dropper, and the stepping motor drives the screw rod to move forwards or backwards to extrude the infusion tube so as to realize the control of the infusion drip speed and the blocking control of the infusion termination;

the electrocardio information acquisition module comprises a guide electrode, lead wires, an electrocardio sensor and a signal conditioning circuit, wherein the three lead wires of the electrocardio sensor are connected with the guide electrode and are respectively placed on the right arm, the left arm and the left leg of the tested person in a pressurized right upper limb single-pole lead mode; the pulse information acquisition module comprises a pulse sensor and a signal conditioning circuit, wherein the pulse sensor is placed at the radial artery of the wrist of the left hand or the right hand of a human body; the blood pressure information acquisition module comprises a cuff, an inflator pump and a control circuit, wherein the cuff is placed on the upper arm of a human body, and the distance between the lower edge of the cuff and the cross grain of the elbow is 2-3 cm;

the storage module adopts an SD card storage mechanism and is used for storing the set value of the dropping speed, the total liquid amount, the residual liquid amount, the real-time dropping speed, the electrocardio, the pulse and the blood pressure monitoring data, and the SD card is communicated with the control unit through an SPI serial port; the alarm reminding module comprises a buzzer and an NPN triode which are electrically connected with the control unit; the LCD display screen is communicated with the control unit through SCI to realize the display of various monitoring information and reminding information; the setting/function selection module is electrically connected with the control unit by adopting a key, and the functions of setting each monitoring threshold and selecting functions are realized by using an inquiry mode detection key;

the monitoring system comprises a real-time monitoring control thread, an electrocardio information acquisition and processing thread, a pulse information acquisition and processing thread and a blood pressure information acquisition and processing thread in the infusion process;

the real-time monitoring control thread of the infusion process comprises the following steps:

(11) setting the dropping speed, the total amount of the liquid medicine and the alarm reminding amount of the residual liquid medicine, sending a reset signal to a dropping speed/blocking control module, and interrupting the counting of the opened liquid drops and interrupting the liquid level;

(12) the watchdog timer is interrupted, and starting signals are sent to the liquid drop sensor and the liquid level sensor;

(13) when the timer times out, calculating the actual dropping speed and the residual liquid medicine amount;

(14) the actual dropping speed and the residual liquid medicine amount are respectively compared with set values, the motor is controlled to adjust the dropping speed, data are stored and transmitted, abnormal conditions are alarmed, if the liquid level is low and the interruption is triggered, the motor is controlled to block transfusion, the transfusion is terminated, and if the liquid level is not low, the step (12) is carried out;

the electrocardio information acquisition and processing thread and the pulse information acquisition and processing thread comprise the following steps:

(21) reading a function setting command or receiving an acquisition command of a data management computer, and starting a timerA timer for interruption;

(22) if the timer counts and overflows, executing an interrupt service program and starting ADC sampling;

(23) after ADC sampling is finished, reading and storing data, sending the data to an LCD display screen for display and actively transmitting the data to a data management computer, and otherwise, continuously waiting for the ADC to finish sampling;

the blood pressure information acquisition and processing thread comprises the following steps:

(31) reading a function setting command or receiving an acquisition command of a data management computer, and sending a blood pressure detection instruction to a blood pressure detection module by a serial port UART 1;

(32) the blood pressure measuring module starts to detect the blood pressure value, if a measurement termination command is received, the measurement is terminated and the step (31) is carried out;

(33) and reading the blood pressure measured value, storing the data, sending the data to an LCD display screen for display, and actively transmitting the data to a data management computer.

2. The infusion monitoring and vital sign monitoring system of claim 1, wherein: the liquid drop sensor adopts a correlation type infrared receiving and transmitting tube IR928-6C/PT928-6C, in the infusion process, according to the dropping condition of liquid drops, the output end of the receiving tube outputs square wave signals after being processed by a corresponding signal conditioning circuit and is electrically connected with an IO port of a control unit, the liquid level sensor adopts a DFRobot non-contact type liquid level sensor, and the output is electrically connected with the IO port of the control unit according to the existence of liquid on a horizontal line where the liquid level sensor is positioned and pulse signals can be output.

3. The infusion monitoring and vital sign monitoring system of claim 1, wherein: the electrocardio sensor adopts an HKD-10A analog quantity electrocardio sensor, and an Ag/AgCl electrode is taken as a guide electrode and is attached to the corresponding position of a human body; the pulse sensor adopts an HK-2000B type pulse sensor, and senses pressure change through a PVDF piezoelectric film element; the blood pressure sensor module adopts a SUPERNIBP200A blood pressure measuring module and is communicated with the control unit through a UART1 serial port.

4. The system for monitoring infusion and monitoring vital signs according to claim 1, wherein the dual power supply module employs a power adapter, the output of which is connected to the input of the power management chip and to the rechargeable lithium battery via a peripheral resistor-capacitor and a field effect transistor, and the output of the power adapter and the output of the lithium battery implement automatic switching between adapter power supply and lithium battery power supply via two diodes.