CN1251660C - Deep vein embolus preventing instrument - Google Patents

Abstract

The invention discloses a device for preventing deep vein thrombosis. It is mainly composed of two parts: control circuit and pneumatic device. Embedded single-chip microcomputer is used as the control core, the air pressure in the air bag is detected by the pressure sensor, and the signal is transmitted to the single-chip microcomputer system through the interface circuit. Execute the action in a certain order, so that the three airbags are inflated and deflated according to the law, and a certain gradient of pressure is applied to the lower limbs of the patient, so as to achieve the purpose of preventing DVT in medicine. The instrument has the advantages of simple structure, low manufacturing cost, stable performance and high degree of intelligence.

Description

Deep Vein Thrombosis Prevention Device

technical field

The invention relates to a physiotherapy device, in particular to a device for preventing deep vein thrombosis.

Background technique

The formation of deep vein thrombosis (Deep Vein Thrombosis, DVT) is due to the obstruction of a deep vein by thrombus, resulting in the obstruction of blood return to the distal side of the thrombus and tissue stasis. With the rapid development of vascular surgery and the popularization and application of various diagnosis and treatment techniques, the detection rate of DVT has increased, and it has become a common and frequently-occurring disease in peripheral vascular disease, and has an increasing trend year by year. Currently, effective measures to prevent DVT are mainly anticoagulant drugs. The application of anticoagulant drugs has bleeding tendency, gastrointestinal adverse reactions and allergic problems, especially for elderly patients and patients with cardiopulmonary insufficiency, they should be used with caution.

Contents of the invention

The purpose of the present invention is to provide a device for preventing deep vein thrombosis, which can prevent DVT by using the mechanical method (elastic pressure) of periodic inflation and pressurization, thereby eliminating the side effects produced by anticoagulant drugs for treating DVT.

Technical solutions:

The technical solution adopted by the present invention to solve its technical problems is: it comprises a control circuit and a pneumatic device, wherein:

1) Control circuit: including single-chip system circuit, keyboard control circuit, display control circuit, buzzer alarm circuit, EEPROM storage circuit, power processing circuit, AD conversion circuit, isolation drive circuit, signal amplification circuit, sensor interface circuit; single-chip system circuit The control pins and I/O port pins are respectively connected to the keyboard control circuit, display control circuit, buzzer alarm circuit, EEPROM storage circuit, power processing circuit, AD conversion circuit and isolation drive circuit, and the AD conversion circuit passes through the signal input port AIN1, AIN2, and AIN3 are respectively connected to the three signal output ports out in the signal amplification circuit, and the three input ports -IN and +IN in the signal amplification circuit are respectively connected to the three output ports in the sensor interface circuit;

2) Pneumatic device: It includes three independent air circuits, each of which has an air intake valve, an air release valve, a four-way joint, a pressure sensor and an air bag; the four-way joint is connected with the air intake valve, air release valve, pressure sensor and The air bag is connected, the intake valve and the deflation valve are respectively connected to the isolation drive circuit, the pressure sensor is connected to the voltage amplification circuit through the sensor interface circuit, and the three intake valves are connected in parallel to a micro air pump.

The beneficial effects that the present invention has are:

After the present invention starts, the control core first reads each key value of the keyboard, and sets each parameter. Then read the converted digital value of the pressure sensor, and through the internal control judgment, output the control signal to control the intake valve and the deflation valve to perform actions according to a certain law, so that the three airbags can be inflated and deflated according to the law, exerting pressure on the lower limbs of the patient. A certain gradient of pressure to achieve the purpose of preventing DVT in medicine. The instrument has the advantages of simple structure, low manufacturing cost, stable performance and high degree of intelligence.

Description of drawings

Fig. 1 is a general structural block diagram of the present invention;

Fig. 2 is a structural principle diagram of the pneumatic device of the present invention;

Fig. 3 is an exploded view of the action of the single-path gas path of the present invention;

Fig. 4 is the main program block diagram of control circuit of the present invention;

Fig. 5 is a control circuit diagram of the present invention.

In the figure: 1. Micro air pump, 2. Inlet valve, 3. Air release valve, 4. Four-way joint, 5. Pressure sensor, 6. Air bag, 7. Sensor interface circuit, 8. Signal amplification circuit, 9. AD conversion circuit, 10. Drive isolation circuit, 11. Single-chip microcomputer system circuit, 12. Keyboard control circuit, 13. Display control circuit, 14. Buzzer alarm circuit, 15. EEPROM storage circuit, 16. Power processing circuit.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Fig. 1 and Fig. 2, the present invention includes a control circuit and a pneumatic device, wherein:

1) Control circuit: including microcontroller system circuit 11, keyboard control circuit 12, display control circuit 13, buzzer alarm circuit 14, EEPROM storage circuit 15, power processing circuit 16, AD conversion circuit 9, isolation drive circuit 10, signal amplification circuit 8. Sensor interface circuit 7. The single-chip microcomputer system circuit 11 is respectively connected with the keyboard control circuit 12, the display control circuit 13, the buzzer alarm circuit 14, the EEPROM storage circuit 15, the power processing circuit 16, the AD conversion circuit 9 and the isolation drive through the control pin and the I/O port pin. The circuit 10 is connected, and the AD conversion circuit 9 is respectively connected to the three signal output ports out in the signal amplification circuit 8 through the signal input ports AIN1, AIN2, and AIN3, and the three input ports -IN and +IN in the signal amplification circuit 8 are respectively connected to the sensor Three output ports are connected in the interface circuit 7;

2) Pneumatic device: including three independent air circuits, each of which has an intake valve 2, an air release valve 3, a four-way joint 4, a pressure sensor 5 and an air bag 6; the four-way joint 4 is connected to the intake valve 2, Air release valve 3, pressure sensor 5 and airbag 6 are connected, intake valve 2 and air release valve 3 are respectively connected to isolation drive circuit 10, pressure sensor 5 is connected to voltage amplification circuit 8 through sensor interface circuit 7, three intake valves 2 The micro air pump 1 is connected after the parallel connection.

The single-chip microcomputer system circuit 11 adopts AT89C52, AT89C2051 or AT89C51; the keyboard control circuit 12 has 4 buttons in total, adopts a 2×2 structure, and the row lines and column lines are directly connected to the P14～P17 ports of the single-chip microcomputer; the display control circuit 13 adopts 6 Bit LED dynamic display, MCU P24~P26 connected to 3~8 decoder 74LS138 input terminal, output 6 useful signals and then amplified by inverter 74LS14 and transistor, connected to LED as bit signal; MCU P20~P23 connected to 4 Line-7-segment decoder/driver 74LS247, output 7-way signal as segment code to connect to LED; buzzer alarm circuit 14, whose buzzer is powered by voltage regulator module 7805, directly connected to P06 of single-chip microcomputer; EEPROM storage circuit 15 is X25045 , using the chip standard circuit; the power processing circuit 16 uses filter diodes and voltage regulator module 7824, voltage regulator module 7805, voltage regulator module 7905, and voltage regulator module LM336 to provide power, and adopts LM324 circuit to reduce voltage to provide reference power for AD620; The AD conversion circuit 9 is AD7706, and adopts the chip standard circuit; the isolation drive circuit 10 is the single chip microcomputer P00～P05, passes through the isolation chip TLP521-2, and then passes through the drive chip ULN2003 to control the intake valve and exhaust valve of each channel; the signal is amplified Circuit 8 adopts AD620 and adopts the standard circuit of this chip; the power supply of sensor interface circuit 7 is provided by LM336 regulated power supply, and then the power processing circuit 16 is isolated by voltage follower LM324.

The intake valve 2 is a two-position two-way solenoid valve, the air discharge valve 3 is a two-position two-way solenoid valve, the four-way joint 4 is an ordinary plastic four-way joint, and the pressure sensor 5 is an MPX10 pressure sensor.

The mechanical and electrical interface part is mainly that the pressure sensor 5 detects the gas pressure in the airbag, and the signal is transmitted to the interface of the signal amplification circuit 8 through the sensor interface circuit 7 . The single-chip microcomputer system circuit 11 sends a signal processed by software, and controls the intake valve 2 and the air discharge valve 3 through the isolation drive circuit 10 . After the instrument starts, the power processing circuit 16 starts to supply power, the micro air pump 1 is turned on, and the single-chip microcomputer system circuit 11 first reads the parameter original value in the EEPROM storage circuit 15, then reads the keyboard control circuit 12 key values, and sets each parameter. Send EEPROM storage circuit 15 to store and display control circuit 13 to display. After the parameter setting is completed, read the digital value of the sensor interface circuit 7 through the voltage amplifying circuit 8 and the AD conversion circuit 9, and judge through the software control of the single-chip system circuit 11, output a control signal, and control the intake valve 2, The deflation valve 3 performs actions according to a certain rule, and the internal air pressure of the four-way joint 4 is connected to make the three airbags 6 charge and deflate according to the rule. When the instrument breaks down and causes the internal pressure to exceed the alarm pressure, or after running the set cycle, the buzzer alarm circuit 14 will alarm.

As shown in the schematic diagram of the air circuit in Figure 2, the air route provides a total air source by a micro air pump 1, which is divided into three independent air circuits. During the implementation of the instrument, the control core of the single-chip system circuit 11 sequentially sends control signals to the intake valve 2 and the deflation valve 3 in the three independent air circuits, so that the three airbags 6 are inflated and deflated sequentially. The control core of the single-chip system circuit 11 first powers on the intake valve 2 in the first circuit, then the air bag 6 in the first circuit is inflated, and when the pressure sensor 5 reaches the set value, the intake valve 2 stops being powered on, The air bag enters the pressure-holding state. After a delay, power on the first air release valve 3, and then the air bag 6 in the first air release. When it is detected that the internal gas pressure drops to atmospheric pressure, the air release valve 3 stops. Turn on the power and end the deflation. After the time delay, perform the same operation on the intake valve 2 and exhaust valve 3 in the next air path until all three air paths are completed, then re-operate the first path to enter a new cycle, thus realizing three airbags 6 Inflate and deflate in turn.

In the implementation process shown in the exploded view of the single air path action in Figure 3, one port of the intake valve 2 is connected to the micro air pump 1, the other port is connected to the four-way joint 4, and one port of the air release valve 3 is connected to the four-way joint. Joint 4 is connected, and the other port is directly communicated with the atmosphere. The other two outlets of the four-way joint are connected with the pressure sensor 5 and the air bag 6 respectively. After the instrument is started, the micro air pump 1 supplies air. When the intake valve 2 is powered on and the exhaust valve 3 is powered off, the intake valve 2 is in the open state, and the gas in the micro air pump 1 passes through the intake valve 2 and directly enters the air bag 6. , and at this time the air release valve 3 is in the closed state, so that the internal gas is isolated from the atmosphere, and the airbag is inflated to pressurize; when the intake valve 2 and the air release valve 3 are powered off at the same time, the intake valve 2 is in the closed state, The micro-air pump 1 is isolated from the internal air circuit and cannot supply air, and at this time, the air release valve 3 is also in a closed state, so that the internal gas is isolated from the atmosphere, and the air ports of the air bag 6 are all closed to maintain pressure; when the air intake valve 2 When the power is off and the deflation valve 3 is powered on, the intake valve 2 is in the closed state, the micro air pump 1 is isolated from the internal air circuit and cannot supply air, and at this time the deflation valve 3 is in the open state, so that the airbag 6 is directly connected to the The atmosphere communicates, deflates and depressurizes. The control core of the single-chip system circuit 11 controls the intake valve 2 and the deflation valve 3 by sending a switch signal to realize the inflation and deflation of a single air bag 6 .

Fig. 4 is a flow chart of the main program, the system starts up, reads various original parameters from the EEPROM storage circuit 15, initializes, and waits for the signal of the "execute" key or the "setting" key. If the "Execute" key responds, the program directly enters the running state; if the "Setting" key responds, the program first enters the parameter setting state. After setting a parameter, the value is sent to the EEPROM storage circuit 15 and sent to the display control circuit 13 for display. . After all parameters are set, it will directly enter the running state. During operation, the software first sets the gas path symbol n=1, performs power-on control on the intake valve 2 in the nth path, and detects the signal output by the A/D converter 9, and sends the measured actual pressure sensor 5 value to The display control circuit 13 shows that until the pressure rises to the set value, the power-off control is performed on the intake valve 2 in the nth circuit. Delay the pressure, and then the software will power-on control the purge valve 3 in the nth circuit, and detect the signal output by the A/D converter 9, and send the actual measured value of the pressure sensor 5 to the display control circuit 13 for display until the pressure When the pressure drops to atmospheric pressure, power-off control is performed on the purge valve 3 in the nth circuit. After the time delay, add one to the sign number n of the gas path, and judge whether a cycle is completed (n=4), and if it is not completed (n<4), perform the same operation on the next path. After the software performs one-side operation on the three gas circuits (n=4), the cycle symbol m is decremented by one, and it is checked whether the cycle symbol m is equal to 0. If it is equal to 0, the program returns, otherwise the program enters the next cycle to run, and then operates on the first channel.

Figure 5 is the circuit diagram of the control part, the circuit components and working principles are as follows: SCM system circuit 11: the core is AT89C52, and its basic unit also includes a 12MHZ crystal resonator. Read and control each branch circuit through control pins and I/O port pins. Keyboard control circuit 12: the instrument has 4 buttons in total—execution reading key, setting key, up key, and down key. In order to save I/O, a 2×2 structure is adopted. When no key is closed on the keyboard, all row lines and column lines are disconnected. When a key on the keyboard is closed, the row and column corresponding to the key are short-circuited. The row lines and column lines are directly connected to the P14-P17 ports of the microcontroller. Display control circuit 13: 6-bit LED dynamic display is adopted, the single-chip microcomputer P24～P26 is connected to the input terminal of 3～8 decoder 74LS138, and 6 routes of useful signals are output, which are then amplified by the inverter 74LS14 and the transistor, and connected to the LED as a bit signal. Single-chip microcomputer P20～P23 is connected to 4-wire-7-segment decoder/driver 74LS247, outputs 7-way signal as segment code, and connects to LED. Signal amplifying circuit 8: AD620 is used as an instrument amplifier, which amplifies the signal output by the sensor and outputs it to the AD conversion circuit 9. AD conversion circuit 9: AD7706 is used for AD conversion, which receives the signal from the signal amplifier circuit 8 and outputs the converted signal directly to the single-chip microcomputer. Power processing circuit 16: adopts 220V mains power supply, and the transformer outputs 24V, 5V and -5V in three circuits. Each channel is rectified by the bridge circuit and filtered by the capacitor, respectively connected to the voltage stabilizing module 7824, the voltage stabilizing module 7805, and the voltage stabilizing module 7905, and the output power is connected to the circuit to provide power for each device. The reference voltage of the AD conversion circuit 9 is output by the reference voltage regulator diode LM336, and then the operational amplifier LM324 is used to form a stable voltage source with good performance, which provides a reliable reference voltage for the amplifying circuit and the AD conversion circuit, and ensures conversion accuracy. Buzzer alarm circuit 14: The buzzer is powered by the voltage regulator module 7805, directly connected to P06 of the single-chip microcomputer, and the status of the buzzer is controlled by software. EEPROM storage circuit 15: The circuit adopts X25045, which contains 4k serial EEPROM. By connecting with the single-chip microcomputer P10-P13, it can save the system parameters in time, in case the system accidentally drops points or can be read again when the system is turned on next time. The chip contains a watchdog circuit, an external button, and provides functions such as software reset and button reset. Sensor interface circuit 7: The sensor uses Motorola MPX10, its power supply is provided by a regulated power supply, and then the forward circuit is isolated by a voltage follower LM324. The output signal is directly input to the input end of the voltage amplifying circuit. Drive isolation circuit 10: single-chip microcomputers P00-P05 control the air intake valve 2 and air discharge valve 3 of each channel through the isolation chip TLP521-2, and then through the drive chip ULN2003.

Claims (3)

1. A device for preventing deep vein thrombosis, characterized in that: it includes a control circuit and a pneumatic device, wherein: 1) Control circuit: including microcontroller system circuit (11), keyboard control circuit (12), display control circuit (13), buzzer alarm circuit (14), EEPROM storage circuit (15), power processing circuit (16), AD Conversion circuit (9), isolation drive circuit (10), signal amplification circuit (8), sensor interface circuit (7); single-chip microcomputer system circuit (11) is connected with keyboard control circuit ( 12), display control circuit (13), buzzer alarm circuit (14), EEPROM storage circuit (15), power processing circuit (16), AD conversion circuit (9) and isolation drive circuit (10) are connected, AD conversion circuit (9) The signal input ports AIN1, AIN2, and AIN3 are respectively connected to the three signal output ports out in the signal amplification circuit (8), and the three input ports -IN and +IN in the signal amplification circuit (8) are respectively connected to the sensor interface Three output ports are connected in the circuit (7); 2) Pneumatic device: including three independent air circuits, each of which has an inlet valve (2), an air release valve (3), a four-way joint (4), a pressure sensor (5) and an air bag (6); four The connection joint (4) is respectively connected with the intake valve (2), the exhaust valve (3), the pressure sensor (5) and the air bag (6), and the intake valve (2) and the exhaust valve (3) are respectively connected to the isolation drive The circuit (10), the pressure sensor (5) is connected with the voltage amplifying circuit (8) through the sensor interface circuit (7), and the three intake valves (2) are connected in parallel and then connected with the miniature air pump (1). 2. A device for preventing deep vein thrombosis according to claim 1, characterized in that: the single-chip system circuit (11) adopts AT89C52, AT89C2051 or AT89C51; ×2 structure, the row lines and column lines are directly connected to the P14～P17 ports of the single-chip microcomputer; the display control circuit (13) adopts 6-bit LED dynamic display, and the single-chip microcomputer P24～P26 is connected to the input terminal of the 3～8 decoder 74LS138, and the output is 6 The useful signal is amplified by the inverter 74LS14 and the transistor, and connected to the LED as a bit signal; the P20~P23 of the single-chip microcomputer is connected to the 4-wire-7-segment decoder/driver 74LS247, and the output 7-way signal is connected to the LED as a segment code; buzzer Its buzzer of alarm circuit (14) is powered by voltage stabilizing module 7805, is directly connected with the P06 of single-chip microcomputer; EEPROM storage circuit (15) is X25045; 7805, voltage stabilizing module 7905 and voltage stabilizing module LM336 provide power supply, and use LM324 circuit to reduce voltage to provide reference power supply for AD620; AD conversion circuit (9) is AD7706; isolation drive circuit (10) is single chip microcomputer P00～P05 through isolation chip TLP521-2, and then through the drive chip ULN2003 to control the intake valve and exhaust valve of each channel; the signal amplification circuit (8) adopts AD620; the power supply of the sensor interface circuit (7) is provided by the regulated power supply LM336, and then followed by the voltage The device LM324 isolates the power processing circuit (16). 3. A device for preventing deep vein thrombosis according to claim 1, characterized in that: the intake valve (2) is a two-position two-way electromagnetic valve, and the air release valve (3) is a two-position two-way electromagnetic valve. The valve and the four-way joint (4) are plastic four-way joints, and the pressure sensor (5) is an MPX10 pressure sensor.

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