Simple device and method for monitoring concentrations of propofol and sevoflurane on line

Abstract

The invention relates to the technical field of anesthetic concentration monitoring, and provides a simple device and method for online monitoring the concentration of propofol and sevoflurane, the simple device comprises an adsorption tube, the outlet end of the adsorption tube is fixedly connected with a first tube body, one end of the first tube body is fixedly connected with a second tube body, and a semipermeable membrane is fixedly connected between the second tube body and the first tube body; a fixing plate is fixedly connected to the outer side of the second pipe body, a motor is fixedly installed on the outer side of the fixing plate, a negative pressure mechanism is arranged at the top ends of the first pipe body and the second pipe body, a detection mechanism is arranged at the outlet end of the negative pressure mechanism, and an air supply mechanism is arranged at the bottom end of the first pipe body. Under the action of the semipermeable membrane, propofol and sevoflurane in gas exhaled by a patient are separated, so that the two substances stay in the first tube body and the second tube body respectively, the separation mode is simple in structure, separation is realized by utilizing the characteristics of propofol and sevoflurane, the stability is high, and the separation cost is lower.

Description

Technical Field

[0001] The invention relates to the technical field of anesthetic drug concentration monitoring, and in particular to a simple device and method for online monitoring of propofol and sevoflurane concentrations. Background Art

[0002] At present, the most commonly used "balanced anesthesia" during surgery is a mixture of propofol and sevoflurane. In the process of maintaining anesthesia for patients using a mixture of propofol and sevoflurane, precise control of the amount of anesthetic used is of great significance for the smooth progress of the operation and the safety of the patient.

[0003] After searching, the Chinese patent publication number CN107179350B disclosed "a simple device for online monitoring of propofol and sevoflurane concentration, comprising: an adsorption tube, a virtual sensor array, a detection module, a vacuum pump and a controller; the adsorption tube is filled with Tenax-TA, with an air flow channel in the middle, the two ends of the adsorption tube are connected to a voltage source, and the inlet is connected to an expiratory tube; the virtual sensor array comprises a quartz plate and a constant temperature module attached to the lower surface of the quartz plate, the quartz plate is engraved with a groove passage, and the upper surface of the quartz plate is covered with a closed plate; the surface of the groove passage is coated with a layer of separation of volatile organic compounds by membrane technology The inlet of the groove passage is connected to the outlet of the adsorption tube, and the outlet of the groove passage is connected to the detection module; the detection module comprises a nozzle, a nozzle cover and a SAW detection platform; the top of the nozzle is a cone, the middle part is a cylinder, the bottom is a bracket plate, and the central axis is provided with an air flow channel running through the entire nozzle; two grooves are opened at the bottom of the cylindrical part of the nozzle, for placing the heating rod and PT100 respectively; the upper end of the nozzle cover is a bracket plate, and the lower end is a circular column, the diameter of the inner circle of the circular column is equal to the bottom diameter of the cone at the top of the nozzle, and the top of the circular column is connected to the SAW detection platform.

[0004] However, in the process of implementing relevant technologies, the above patent has technical defects. Among them, the above patent separates propofol and sevoflurane in the patient's exhaled gas through a virtual sensor array, wherein the virtual sensor array requires multiple groups of sensors to cooperate, the electronic control circuit is complex and the stability is poor. Once one of the sensors fails, it will affect the normal operation of the whole. In view of this, the present invention proposes a simple device and method for online monitoring of the concentration of propofol and sevoflurane. Summary of the invention

[0005] The invention provides a simple device and method for online monitoring of the concentrations of propofol and sevoflurane, which solves the problem of poor stability in the prior art.

[0006] The technical solution of the present invention is as follows: a simple device for online monitoring of propofol and sevoflurane concentrations, comprising an adsorption tube for introducing patient exhaled gas, wherein the outlet end of the adsorption tube is fixedly connected to a first tube body, one end of the first tube body is fixedly connected to a second tube body, a semipermeable membrane is fixedly connected between the second tube body and the first tube body, a fixing plate is fixedly connected to the outer side of the second tube body, a motor is fixedly installed on the outer side of the fixing plate, the top ends of the first tube body and the second tube body are provided with a negative pressure mechanism for intermittently sucking out the gas in the first tube body and the second tube body by cooperating with the start of the motor, the outlet end of the negative pressure mechanism is provided with a detection mechanism for detecting the concentration of the inhaled gas component, and the bottom end of the first tube body is provided with an air supply mechanism for intermittently introducing hot air to the outer wall of the semipermeable membrane by cooperating with the start of the motor.

[0007] Preferably, an expansion tube is fixedly connected to the adsorption tube, and the inner side of the expansion tube is filled with an adsorbent for absorbing moisture and volatile organic matter in the patient's exhaled gas.

[0008] Preferably, the negative pressure mechanism includes a first negative pressure cylinder, one end of the first negative pressure cylinder is fixedly connected to the second negative pressure cylinder, the inner side of the first negative pressure cylinder is slidably connected to the first piston, the inner side of the second negative pressure cylinder is slidably connected to the second piston, a sliding rod that passes through the side walls of the first negative pressure cylinder and the second negative pressure cylinder is fixedly connected between the second piston and the first piston, the sliding rod is slidably connected to the side walls of the first negative pressure cylinder and the second negative pressure cylinder, and one end of the sliding rod is provided with a transmission member that drives the sliding rod to slide back and forth by cooperating with the drive of the motor.

[0009] Preferably, the negative pressure mechanism also includes a first feed pipe, the inlet end of the first feed pipe is connected to the interior of the first tube body, the outlet end of the first feed pipe is connected to the inlet end of the first negative pressure cylinder, the outlet end of the first negative pressure cylinder is fixedly connected to a first discharge pipe, the inlet end of the second negative pressure cylinder is fixedly connected to a second feed pipe, the inlet end of the second feed pipe is connected to the interior of the second tube body, and the outlet end of the second negative pressure cylinder is fixedly connected to a second discharge pipe.

[0010] Preferably, the first feed pipe is fixedly connected with a first feed one-way valve, the first discharge pipe is fixedly connected with a first discharge one-way valve, the second feed pipe is fixedly connected with a second feed one-way valve, and the second discharge pipe is fixedly connected with a second discharge one-way valve.

[0011] Preferably, the transmission member includes a connecting plate, the top end of the connecting plate is fixedly connected to the sliding rod, the bottom end of the connecting plate is threadedly connected to a reciprocating screw, one end of the reciprocating screw is rotatably connected to the fixed plate, the other end of the reciprocating screw is fixedly connected to a stopper, the middle part of the reciprocating screw is fixedly connected to a first gear, and the output shaft of the motor is fixedly connected to a second gear meshing with the first gear.

[0012] Preferably, the detection mechanism includes a detection box, the outlet ends of the first discharge pipe and the second discharge pipe are fixedly connected to the detection box, a SAW sensor for detecting the concentrations of propofol and sevoflurane is fixedly connected to the inner side of the detection box, and a discharge pipe is fixedly connected to one side of the detection box.

[0013] Preferably, a control panel is fixedly connected to the top of the detection box, and the control panel includes a processor and a signal sending module electrically connected to the processor, the signal output end of the signal sending module is connected to the control terminal signal, and the SAW sensor is connected to the processor signal.

[0014] Preferably, the air supply mechanism includes an air cylinder fixedly connected to the top of the fixed plate, the inner side of the air cylinder is rotatably connected to a blowing impeller, one end of the air cylinder is provided with a plurality of through air inlet holes, the other end of the air cylinder is fixedly connected to an air guide pipe, the outlet end of the air guide pipe is connected to the interior of the first tube body, a heater for heating the air inside the air cylinder is fixedly installed on the inner side of the air cylinder, the outer side of the air cylinder is rotatably connected to a third gear coaxially fixed with the blowing impeller, the output shaft of the motor is fixedly connected to an incomplete gear, and the incomplete gear is intermittently meshed with the third gear.

[0015] The present invention also provides a method for online monitoring of propofol and sevoflurane concentrations, which is implemented according to a simple device for online monitoring of propofol and sevoflurane concentrations, and comprises the following steps:

[0016] S1: When the anesthetized patient enters passive breathing, the inlet end of the adsorption tube is connected to the patient's exhalation tube, so that the patient's exhaled gas is introduced into the first tube body through the adsorption tube;

[0017] S2: The patient's exhaled gas continues to be introduced into the second tube body, and the propofol and sevoflurane in the patient's exhaled gas are separated under the action of the semipermeable membrane, so that the two substances remain in the first tube body and the second tube body respectively;

[0018] S3: starting the motor so that the air supply mechanism intermittently introduces hot air to the outer wall of the semipermeable membrane, so that the temperature of the outer wall of the semipermeable membrane increases, and the substances attached to the outer wall of the semipermeable membrane are desorbed;

[0019] S4: When the motor is started, it drives the negative pressure mechanism to intermittently introduce the substances in the first tube body and the second tube body into the detection mechanism in turn, and the concentrations of propofol and sevoflurane are detected in turn through the detection mechanism, and finally the concentrations of propofol and sevoflurane in the patient's exhaled gas are detected.

[0020] The working principle and beneficial effects of the present invention are as follows: by connecting the inlet end of the adsorption tube to the patient's exhalation tube, the gas exhaled by the patient is introduced into the first tube body through the adsorption tube, and the gas exhaled by the patient is continuously introduced into the second tube body. Under the action of the semipermeable membrane, propofol and sevoflurane in the gas exhaled by the patient are separated, so that the two substances stay in the first tube body and the second tube body respectively. This separation method has a simple structure, utilizes the characteristics of propofol and sevoflurane themselves to achieve separation, has high stability, and has lower separation cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0022] Figure 1 It is a structural schematic diagram of a simple device for online monitoring of propofol and sevoflurane concentrations of the present invention;

[0023] Figure 2 It is a structural schematic diagram of a simple device for online monitoring of propofol and sevoflurane concentrations of the present invention;

[0024] Figure 3 It is a schematic diagram of the internal structure of the adsorption tube of the present invention;

[0025] Figure 4 It is a structural schematic diagram of the negative pressure mechanism of the present invention;

[0026] Figure 5 It is a structural schematic diagram of the transmission member of the present invention;

[0027] Figure 6 It is a structural schematic diagram of the detection mechanism of the present invention;

[0028] Figure 7 is a system block diagram of the present invention;

[0029] Figure 8 It is a structural schematic diagram of the air supply mechanism of the present invention.

[0030] In the figure: 1, adsorption tube; 11, expansion tube; 12, adsorbent; 2, first tube body; 3, second tube body; 4, semipermeable membrane; 5, fixing plate; 6, motor; 7, negative pressure mechanism; 71, first negative pressure cylinder; 72, second negative pressure cylinder; 73, first piston; 74, second piston; 75, sliding rod; 76, first feed pipe; 761, first feed check valve; 77, second feed pipe; 771, second feed check valve; 78, first discharge pipe; 781, first discharge check valve; 79 , second discharge pipe; 791, second discharge one-way valve; 70, transmission member; 701, connecting plate; 702, reciprocating screw rod; 703, stopper; 704, first gear; 705, second gear; 8, detection mechanism; 81, detection box; 82, SAW sensor; 83, discharge pipe; 84, control panel; 9, air supply mechanism; 91, air cylinder; 92, blowing impeller; 93, air inlet; 94, heater; 95, air guide duct; 96, third gear; 97, incomplete gear. DETAILED DESCRIPTION

[0031] The following will be combined with the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0032] like Figures 1 to 8 As shown, this embodiment proposes a simple device for online monitoring of propofol and sevoflurane concentrations, including an adsorption tube 1 for introducing patient exhaled gas, the adsorption tube 1 is fixedly connected with an expansion tube 11, and the inner side of the expansion tube 11 is filled with an adsorbent 12 for absorbing moisture and volatile organic matter in the patient's exhaled gas; the outlet end of the adsorption tube 1 is fixedly connected with a first tube body 2, one end of the first tube body 2 is fixedly connected with a second tube body 3, a semipermeable membrane 4 is fixedly connected between the second tube body 3 and the first tube body 2, a fixing plate 5 is fixedly connected to the outer side of the second tube body 3, a motor 6 is fixedly installed on the outer side of the fixing plate 5, the top ends of the first tube body 2 and the second tube body 3 are provided with a negative pressure mechanism 7 for intermittently sucking out the gas in the first tube body 2 and the second tube body 3 by cooperating with the start of the motor 6, the outlet end of the negative pressure mechanism 7 is provided with a detection mechanism 8 for detecting the concentration of the inhaled gas component, and the bottom end of the first tube body 2 is provided with an air supply mechanism 9 for intermittently introducing hot air to the outer wall of the semipermeable membrane 4 by cooperating with the start of the motor 6.

[0033] By connecting the inlet end of the adsorption tube 1 to the patient's exhalation tube, the patient's exhaled gas is introduced into the first tube body 2 through the adsorption tube 1, and the patient's exhaled gas is further introduced into the second tube body 3. Under the action of the semipermeable membrane 4, the propofol and sevoflurane in the patient's exhaled gas are separated, so that the two substances remain in the first tube body 2 and the second tube body 3 respectively. This separation method has a simple structure, utilizes the characteristics of propofol and sevoflurane themselves to achieve separation, has high stability, and has lower separation cost.

[0034] Furthermore, the negative pressure mechanism 7 includes a first negative pressure cylinder 71, one end of the first negative pressure cylinder 71 is fixedly connected to the second negative pressure cylinder 72, the inner side of the first negative pressure cylinder 71 is slidably connected to the first piston 73, the inner side of the second negative pressure cylinder 72 is slidably connected to the second piston 74, a sliding rod 75 that passes through the side walls of the first negative pressure cylinder 71 and the second negative pressure cylinder 72 is fixedly connected between the second piston 74 and the first piston 73, the sliding rod 75 is slidably connected to the side walls of the first negative pressure cylinder 71 and the second negative pressure cylinder 72, one end of the sliding rod 75 is provided with a transmission member 70 that drives the sliding rod 75 to slide back and forth by cooperating with the drive of the motor 6, and the inlet end of the first tube body 2 is fixedly connected to the first feeding pipe 7 6. The outlet end of the first feed pipe 76 is connected to the inlet end of the first negative pressure cylinder 71, the outlet end of the first negative pressure cylinder 71 is fixedly connected with the first discharge pipe 78, the inlet end of the second negative pressure cylinder 72 is fixedly connected with the second feed pipe 77, the inlet end of the second feed pipe 77 is connected to the inside of the second tube body 3, the outlet end of the second negative pressure cylinder 72 is fixedly connected with the second discharge pipe 79, the first feed pipe 76 is fixedly connected with the first feed check valve 761, the first discharge pipe 78 is fixedly connected with the first discharge check valve 781, the second feed pipe 77 is fixedly connected with the second feed check valve 771, and the second discharge pipe 79 is fixedly connected with the second discharge check valve 791.

[0035] By starting the motor 6, the transmission member 70 drives the slide bar 75 to slide back and forth, so that the second piston 74 and the first piston 73 slide synchronously. When the slide bar 75 slides to the outside of the second negative pressure cylinder 72, the first piston 73 approaches the first feed pipe 76, and the second piston 74 moves away from the second feed pipe 77, so that the pressure inside the first negative pressure cylinder 71 increases and the pressure inside the second negative pressure cylinder 72 decreases, which makes the second feed pipe 77 suck the material inside the second tube body 3, and the first discharge pipe 78 discharges the air inside the first negative pressure cylinder 71;

[0036] When the slide rod 75 slides toward the interior of the second negative pressure cylinder 72, the first piston 73 and the second piston 74 slide in opposite directions, so that the internal pressure of the first negative pressure cylinder 71 decreases and the internal pressure of the second negative pressure cylinder 72 increases, which causes the second discharge pipe 79 to introduce the inhaled substance into the detection mechanism 8 for detection. At the same time, the first feed pipe 76 inhales the substance inside the first tube body 2 into the first negative pressure cylinder 71. The cycle continues like this, and the second discharge pipe 79 and the first discharge pipe 78 successively and intermittently introduce the propofol and sevoflurane separated from the exhaled gas into the detection mechanism 8 for concentration detection, thereby avoiding the problem of errors in the detection results caused by mutual interference between propofol and sevoflurane.

[0037] Furthermore, the transmission member 70 includes a connecting plate 701, the top of which is fixedly connected to the sliding rod 75, the bottom end of the connecting plate 701 is threadedly connected to a reciprocating screw 702, one end of the reciprocating screw 702 is rotatably connected to the fixed plate 5, the other end of the reciprocating screw 702 is fixedly connected to a stopper 703, the middle of the reciprocating screw 702 is fixedly connected to a first gear 704, and the output shaft of the motor 6 is fixedly connected to a second gear 705 meshing with the first gear 704.

[0038] By starting the motor 6 to rotate the second gear 705, the first gear 704 rotates synchronously, which causes the reciprocating screw 702 to rotate, causing the connecting plate 701 to reciprocate along the axis of the reciprocating screw 702, and causing the slide bar 75 to slide back and forth.

[0039] Furthermore, the detection mechanism 8 includes a detection box 81, the outlet ends of the first discharge pipe 78 and the second discharge pipe 79 are fixedly connected to the detection box 81, the inner side of the detection box 81 is fixedly connected with a SAW sensor 82 for detecting the concentration of propofol and sevoflurane, one side of the detection box 81 is fixedly connected with a discharge pipe 83, and the top of the detection box 81 is fixedly connected with a control panel 84, the control panel 84 includes a processor, a signal sending module electrically connected to the processor, the signal output end of the signal sending module is connected to the control terminal signal, and the SAW sensor 82 is connected to the processor signal. The SAW sensor 82 can detect the concentration of propofol and sevoflurane respectively, and at the same time send the detection data to the processor, and then send the data signal to the control terminal through the signal sending module for online monitoring, so as to facilitate medical staff to accurately control the amount of anesthetic used.

[0040] Furthermore, the air supply mechanism 9 includes a wind tube 91 fixedly connected to the top of the fixed plate 5, the inner side of the wind tube 91 is rotatably connected to a blowing impeller 92, one end of the wind tube 91 is provided with a plurality of through air inlet holes 93, the other end of the wind tube 91 is fixedly connected to an air guide pipe 95, the outlet end of the air guide pipe 95 is connected to the interior of the first tube body 2, a heater 94 for heating the air inside the wind tube 91 is fixedly installed on the inner side of the wind tube 91, the outer side of the wind tube 91 is rotatably connected to a third gear 96 coaxially fixed with the blowing impeller 92, the output shaft of the motor 6 is fixedly connected to an incomplete gear 97, and the incomplete gear 97 is intermittently meshed with the third gear 96. The incomplete gear 97 is driven to rotate by the motor 6. When the incomplete gear 97 is engaged with the third gear 96, the third gear 96 rotates, and the blowing impeller 92 rotates synchronously. At the same time, the heater 94 heats the air inside the wind tube 91, so that the air guide duct 95 guides the hot air into the first tube body 2 and contacts the outer wall of the semipermeable membrane 4, so that the temperature of the outer wall of the semipermeable membrane 4 increases, and the substances attached to the outer wall of the semipermeable membrane 4 are desorbed.

[0041] The present invention also provides a method for online monitoring of propofol and sevoflurane concentrations, which is implemented according to a simple device for online monitoring of propofol and sevoflurane concentrations, and comprises the following steps:

[0042] S1: When the anesthetized patient enters passive breathing, the inlet end of the adsorption tube 1 is connected to the patient's exhalation tube, so that the patient's exhaled gas is introduced into the first tube body 2 through the adsorption tube 1;

[0043] S2: The patient's exhaled gas continues to be introduced into the second tube body 3, and the propofol and sevoflurane in the patient's exhaled gas are separated under the action of the semipermeable membrane 4, so that the two substances remain in the first tube body 2 and the second tube body 3 respectively;

[0044] S3: The motor 6 is started to drive the incomplete gear 97 to rotate. When the incomplete gear 97 is meshed with the third gear 96, the third gear 96 rotates, and the impeller 92 rotates synchronously. At the same time, the heater 94 heats the air inside the air cylinder 91, so that the air guide 95 guides the hot air into the first tube body 2 and contacts the outer wall of the semipermeable membrane 4, so that the temperature of the outer wall of the semipermeable membrane 4 increases, so that the substances attached to the outer wall of the semipermeable membrane 4 are desorbed;

[0045] S4: When the motor 6 is started, the second gear 705 will rotate, causing the first gear 704 to rotate synchronously, which will cause the reciprocating screw 702 to rotate, causing the connecting plate 701 to reciprocate along the axial direction of the reciprocating screw 702, which will cause the sliding rod 75 to slide back and forth, causing the second piston 74 to slide synchronously with the first piston 73. When the sliding rod 75 slides toward the outside of the second negative pressure cylinder 72, the first piston 73 approaches the first feeding pipe 76, and the second piston 74 moves away from the second feeding pipe 77, causing the internal pressure of the first negative pressure cylinder 71 to increase, and the internal pressure of the second negative pressure cylinder 72 to decrease, which causes the second feeding pipe 77 to suck the material inside the second tube body 3, and at the same time, the first discharge pipe 78 sucks the material inside the first negative pressure cylinder 71. The air is discharged, and when the slide rod 75 slides toward the inside of the second negative pressure cylinder 72, the first piston 73 and the second piston 74 slide in opposite directions, so that the internal pressure of the first negative pressure cylinder 71 decreases and the internal pressure of the second negative pressure cylinder 72 increases, which makes the second discharge pipe 79 introduce the inhaled substance into the detection mechanism 8 for detection, and at the same time the first feed pipe 76 inhales the substance inside the first tube body 2 into the first negative pressure cylinder 71. In this cycle, the second discharge pipe 79 and the first discharge pipe 78 successively introduce the propofol and sevoflurane separated from the exhaled gas into the detection mechanism 8 intermittently for concentration detection. In this way, the concentrations of the two substances can be detected by one sensor, which greatly saves costs and finally detects the concentrations of propofol and sevoflurane in the patient's exhaled gas.

[0046] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A simple device for online monitoring of propofol and sevoflurane concentrations, comprising an adsorption tube (1) for introducing patient exhaled gas, wherein the outlet end of the adsorption tube (1) is fixedly connected to a first tube body (2), and one end of the first tube body (2) is fixedly connected to a second tube body (3), characterized in that: A semipermeable membrane (4) is fixedly connected between the second tube body (3) and the first tube body (2); a fixing plate (5) is fixedly connected to the outer side of the second tube body (3); a motor (6) is fixedly installed on the outer side of the fixing plate (5); a negative pressure mechanism (7) is provided at the top end of the first tube body (2) and the second tube body (3) for intermittently sucking out the gas in the first tube body (2) and the second tube body (3) by cooperating with the start of the motor (6); a detection mechanism (8) is provided at the outlet end of the negative pressure mechanism (7) for detecting the concentration of the inhaled gas components; and a wind supply mechanism (9) is provided at the bottom end of the first tube body (2) for intermittently introducing hot air to the outer wall of the semipermeable membrane (4) by cooperating with the start of the motor (6).

2. A simple device for online monitoring of propofol and sevoflurane concentrations according to claim 1, characterized in that: The adsorption tube (1) is fixedly connected to an expansion tube (11), and the inner side of the expansion tube (11) is filled with an adsorbent (12) for absorbing moisture and volatile organic matter in the patient's exhaled gas.

3. A simple device for online monitoring of propofol and sevoflurane concentrations according to claim 1, characterized in that: The negative pressure mechanism (7) comprises a first negative pressure cylinder (71), one end of which is fixedly connected to a second negative pressure cylinder (72), a first piston (73) is slidably connected to the inner side of the first negative pressure cylinder (71), a second piston (74) is slidably connected to the inner side of the second negative pressure cylinder (72), a sliding rod (75) penetrating the side walls of the first negative pressure cylinder (71) and the second negative pressure cylinder (72) is fixedly connected between the second piston (74) and the first piston (73), the sliding rod (75) is slidably connected to the side walls of the first negative pressure cylinder (71) and the second negative pressure cylinder (72), and a transmission member (70) is provided at one end of the sliding rod (75) for driving the sliding rod (75) to slide back and forth by cooperating with the drive of the motor (6).

4. A simple device for online monitoring of propofol and sevoflurane concentrations according to claim 3, characterized in that: The negative pressure mechanism (7) also includes a first feed pipe (76), the inlet end of the first feed pipe (76) is connected to the interior of the first tube body (2), the outlet end of the first feed pipe (76) is connected to the inlet end of the first negative pressure cylinder (71), the outlet end of the first negative pressure cylinder (71) is fixedly connected to a first discharge pipe (78), the inlet end of the second negative pressure cylinder (72) is fixedly connected to a second feed pipe (77), the inlet end of the second feed pipe (77) is connected to the interior of the second tube body (3), and the outlet end of the second negative pressure cylinder (72) is fixedly connected to a second discharge pipe (79).

5. A simple device for online monitoring of propofol and sevoflurane concentrations according to claim 4, characterized in that: The first feed pipe (76) is fixedly connected to a first feed check valve (761), the first discharge pipe (78) is fixedly connected to a first discharge check valve (781), the second feed pipe (77) is fixedly connected to a second feed check valve (771), and the second discharge pipe (79) is fixedly connected to a second discharge check valve (791).

6. A simple device for online monitoring of propofol and sevoflurane concentrations according to claim 5, characterized in that: The transmission member (70) comprises a connecting plate (701), the top end of the connecting plate (701) is fixedly connected to the sliding rod (75), the bottom end of the connecting plate (701) is threadedly connected to a reciprocating screw (702), one end of the reciprocating screw (702) is rotatably connected to the fixed plate (5), the other end of the reciprocating screw (702) is fixedly connected to a stopper (703), the middle part of the reciprocating screw (702) is fixedly connected to a first gear (704), and the output shaft of the motor (6) is fixedly connected to a second gear (705) meshing with the first gear (704).

7. A simple device for online monitoring of propofol and sevoflurane concentrations according to claim 5, characterized in that: The detection mechanism (8) comprises a detection box (81), the outlet ends of the first discharge pipe (78) and the second discharge pipe (79) are fixedly connected to the detection box (81), a SAW sensor (82) for detecting the concentration of propofol and sevoflurane is fixedly connected to the inner side of the detection box (81), and a discharge pipe (83) is fixedly connected to one side of the detection box (81).

8. A simple device for online monitoring of propofol and sevoflurane concentrations according to claim 7, characterized in that: A control panel (84) is fixedly connected to the top of the detection box (81), and the control panel (84) comprises a processor and a signal sending module electrically connected to the processor, a signal output end of the signal sending module is signal-connected to a control terminal, and the SAW sensor (82) is signal-connected to the processor.

9. A simple device for online monitoring of propofol and sevoflurane concentrations according to claim 1, characterized in that: The air supply mechanism (9) comprises a wind tube (91) fixedly connected to the top of the fixed plate (5), the inner side of the wind tube (91) is rotatably connected to a blowing impeller (92), one end of the wind tube (91) is provided with a plurality of through air inlet holes (93), the other end of the wind tube (91) is fixedly connected to an air guide pipe (95), the outlet end of the air guide pipe (95) is connected to the interior of the first tube body (2), the inner side of the wind tube (91) is fixedly installed with a heater (94) for heating the air inside the wind tube (91), the outer side of the wind tube (91) is rotatably connected to a third gear (96) coaxially fixed with the blowing impeller (92), the output shaft of the motor (6) is fixedly connected to an incomplete gear (97), and the incomplete gear (97) is intermittently meshed with the third gear (96).

10. A method for online monitoring of propofol and sevoflurane concentrations, implemented according to a simple device for online monitoring of propofol and sevoflurane concentrations according to any one of claims 1 to 9, characterized in that: The steps include: S1: When the anesthetized patient enters passive breathing, the inlet end of the adsorption tube (1) is connected to the patient's exhalation tube, so that the gas exhaled by the patient is introduced into the interior of the first tube body (2) through the adsorption tube (1); S2: The patient's exhaled gas continues to be introduced into the second tube body (3), and the propofol and sevoflurane in the patient's exhaled gas are separated under the action of the semipermeable membrane (4), so that the two substances remain in the first tube body (2) and the second tube body (3) respectively; S3: starting the motor (6) so that the air supply mechanism (9) intermittently introduces hot air to the outer wall of the semipermeable membrane (4), thereby increasing the temperature of the outer wall of the semipermeable membrane (4) and causing substances attached to the outer wall of the semipermeable membrane (4) to be desorbed; S4: When the motor (6) is started, it drives the negative pressure mechanism (7) to intermittently introduce the substances in the first tube body (2) and the second tube body (3) into the detection mechanism (8) in turn, and the concentrations of propofol and sevoflurane are detected in turn through the detection mechanism (8), and finally the concentrations of propofol and sevoflurane in the patient's exhaled gas are detected.

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