Constant temperature control device and method based on air bath

Abstract

The invention discloses a constant-temperature control device and method based on an air bath, relates to the field of constant-temperature control, and solves the problems of non-uniform temperature, limited temperature control precision, limited heating and cooling speed and the like of a constant-temperature control device in the existing nucleic acid amplification field. The device comprises a turbulent flow fan, a rectifier, a guide pipe, a heating cylinder, a turbulent flow fan and a servo motor, the turbulent flow fan is connected with the rectifier and is mounted above the machine upper cover; the rectifier is connected with the guide pipe; the guide pipe is fastened with the heating cylinder; the turbulent flow fan and the base are installed in a matched mode, the servo motor is connected with the turbulent flow fan, and the turbulent flow fan is driven by the servo motor to operate. And the heating cylinder is fastened with the machine upper cover and is vertically arranged right above the micro-fluidic chip bracket. The centrifugal force and aerodynamics are effectively combined, the temperature of the air bathroom is controlled in a mechanical mode, the problem of non-uniformity of the temperature is avoided, and the device is further suitable for the field of constant-temperature control of nucleic acid amplification experiments.

Description

Technical Field

[0001] The present invention relates to the technical field of constant temperature control, and particularly relates to a constant temperature control device and method based on an air bath. Background Art

[0002] It plays a crucial role in many fields such as life science research, clinical diagnosis, forensic identification, etc., and has greatly promoted the development of related fields. The core of nucleic acid amplification technology is to achieve specific amplification of DNA through precise temperature control. Its process mainly includes three stages: high-temperature denaturation, low-temperature annealing, and appropriate-temperature extension. Each stage has strict requirements for temperature. Although nucleic acid amplification technology has been quite mature and the temperature control system is constantly improving, there are still problems in current nucleic acid amplification temperature control such as uneven temperature, limited temperature control accuracy, and limitations in heating and cooling rates.

[0003] When designing a nucleic acid amplification device, it must be considered that during the heating process, due to the limitation of heat conduction, the temperature at different positions of the reaction vessel will be different. For example, compared with the central area of the heating block, the temperature at the edge may have an obvious deviation. This temperature non-uniformity will lead to inconsistent reaction processes at different positions. The DNA amplification efficiency in some wells may be higher, while in some wells it may be lower, and even amplification failure may occur. This will not only affect the accuracy of experimental results but also bring difficulties to subsequent data statistics and analysis.

[0004] After analyzing and comparing existing nucleic acid amplification methods, existing PCR temperature control systems and PCR detectors. The PCR temperature control system includes a temperature control base, an electromagnetic heating device, and a liquid cooling device. The temperature control base is formed with an insertion space for fitting and inserting a PCR reaction tube. The electromagnetic heating device is arranged on the temperature control base and is used for electromagnetic heating of the temperature control base. The liquid cooling device includes a liquid cooling head. The liquid cooling head is sleeved on the outer peripheral wall of the insertion space and forms a liquid cooling flow channel. Liquid inlets and outlets communicating with the liquid cooling flow channel are opened on opposite sides of the liquid cooling head. Then, the temperature control base can be directly heated by electromagnetic heating without heat transfer thermal resistance, and can be cooled by convection through contact with the coolant. However, this will result in uneven heating of the periphery and the inside of the reaction tube, and there are differences in the heating and cooling rate changes. This electromagnetic heating method cannot quickly and accurately reach the required temperature, and the liquid cooling device is not convenient for carrying and transporting, and is troublesome to operate, with a slow cooling rate. There may be liquid leakage at the liquid outlet and liquid inlet, affecting life safety. It is not conducive to popularization and application. Summary of the Invention

[0005] The present invention aims at the problems existing in the prior art that in the field of nucleic acid amplification, the constant temperature control device still has problems such as uneven temperature, limited temperature control accuracy, and limitations in heating and cooling rates.

[0006] To solve the above technical problems, the present invention is realized through the following technical solutions: Solution 1: The present invention provides a constant temperature control device based on air bath. The device includes a turbulent flow fan, a rectifier, a guiding pipe, a heating cylinder, a microfluidic chip carrier, a base, a turbulent flow fan, a servo motor, a sealing plate, an upper cover, and a bracket. The turbulent flow fan is connected to the rectifier, and the rectifier and the guiding pipe are fixed by bolted connection to the threads on the sealing plate. The guiding pipe wraps around the heating cylinder for firm connection. The turbulent flow fan is installed on the base, and the servo motor is directly connected to the turbulent flow fan to drive the turbulent flow fan to rotate. The heating cylinder is vertically above the microfluidic chip carrier.

[0007] Furthermore, a preferred embodiment is provided. The device further includes a baffle plate, which is trapezoidal in shape and installed on the upper side inside the rectifier. The baffle plate is connected to the rectifier by welding.

[0008] Furthermore, a preferred embodiment is provided. The device further includes a rectifying plate, which is in the shape of a wing-shaped double-leaf fan blade and is used to adjust the form of the air blown by the turbulent flow fan. Four rectifying plates form a rectifying body.

[0009] Furthermore, a preferred embodiment is provided. The device further includes hot film anemometers. Two hot film anemometers are provided on the rectifier, and four hot film anemometers are provided on the base, which are used to detect the air flow rate input by the turbulent flow fan to the rectifier after being sorted and the remaining air flow rate reaching the bottom after passing through the guiding pipe and the heating cylinder.

[0010] Furthermore, a preferred embodiment is provided. The device further includes a carrier retaining ring bracket and a microfluidic chip sealing cover. The microfluidic chip sealing cover is located below the upper cover and is installed on the microfluidic chip carrier, and is connected to the microfluidic chip sealing cover by a flange structure.

[0011] Furthermore, a preferred embodiment is provided. The device further includes a toothed sealing ring. The outer edge of the connection between the base and the upper cover is connected to the toothed sealing ring by a coupling connection. The toothed sealing ring is in the shape of a toothed hollow ring with a thickness of 8 mm, and the microfluidic chip carrier is rotated by the coupling.

[0012] Furthermore, a preferred embodiment is provided. The heating cylinder includes a heating wire and a heating wire skeleton. The heating wire skeleton is a cross-shaped skeleton, and the heating wire is wound around the outer surface of the heating wire skeleton.

[0013] Furthermore, a preferred embodiment is provided. The turbulent flow fan is a nine-leaf right-angle fan blade centrifugal cooling fan.

[0014] Further, a preferred embodiment is provided. Four optical systems and four T-type thermocouple temperature sensors are also provided on the surface of the base. The four T-type thermocouple temperature sensors are 90 degrees apart from each other. The four hot film anemometers provided on the base are simultaneously inserted between the T-type thermocouple temperature sensors and the four optical systems.

[0015] Solution 2: A control method for a constant temperature control device based on an air bath. The control method is implemented based on a constant temperature control device based on an air bath described in any one of Solution 1. The control method is applied to nucleic acid amplification experiments. The control method includes the following steps: Step 1: Install the prepared mixed reagent and sample on the microfluidic chip carrier between the turbulent flow fan and the heating cylinder. Step 2: Start the device. Use the door state detection sensor to detect whether the upper cover is tightly closed. If it is not tight, an alarm will be issued until the upper cover is tight and then proceed to Step 3. The irregular wind blown out by the turbulent flow fan enters the rectifier. After being sorted by the four rectifying plates and baffle plates in the rectifier, regular wind is output. If irregular wind appears behind the rectifying plate, it will be returned to the rectifying plate by the baffle plate for re-filtering until all the wind passing through the rectifying plate is regular wind. The baffle plate guides it to the pipe connection. Step 3: The heating wire in the heating cylinder quickly heats up to the required temperature in the detection chamber, and the regular wind entering from the pipe is passed through the heating cylinder. The heating wire in the heating cylinder changes its temperature according to the temperature requirement in the nucleic acid detection chamber. Taking 120 temperature cycles as a period, when the heating wire lights up and shows red, it is in the heating state; when the brightness of the heating wire decreases, it is in the cooling state. Step 4: The hot film anemometer installed above the base detects whether the temperature transmitted from the heating cylinder meets the nucleic acid amplification temperature. If it meets the requirement, the servo motor drives the turbulent flow fan to rotate stably, so that the hot air flowing out of the heating cylinder is blown to the whole device surrounding the surface of the microfluidic chip to make the reaction sufficient. If it does not meet the requirement, the servo motor controls the rotation of the turbulent flow fan. When the hot film anemometer detects that the air flow is too small, the increased rotation speed is 0.5 times the lack of air flow of the turbulent flow fan and the heating cylinder raises the temperature by more than 10 degrees above the normal temperature. If the hot film anemometer detects that the air flow is too large, the increased rotation speed is 0.6 times the lack of air flow of the turbulent flow fan and the heating cylinder raises the temperature by more than 3 degrees above the normal temperature. Step 5: Adjust the rotation speed of the turbulent flow fan through the servo motor, and at the same time adjust the temperature of the heating wire in the heating cylinder to complete the constant temperature control of the air bath.

[0016] The beneficial effects of the present invention are as follows: The constant temperature control device and control method based on air bath according to the present invention effectively combines centrifugal force and aerodynamics, and uses a mechanical method to control the temperature of the air bath, so as to prevent the problem of temperature non-uniformity. At the same time, the present invention can also meet the requirements of rapid and accurate temperature rise and fall. This device has the characteristics of temperature uniformity, rapid temperature rise and fall, simple operation, safety and low cost.

[0017] The present invention is also applicable to the field of constant temperature control for nucleic acid amplification experiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 The external view of a constant temperature control device based on air bath according to Embodiment 1.

[0019] Figure 2 The sectional view of a constant temperature control device based on air bath according to Embodiment 1.

[0020] Figure 3 The axonometric sectional view of a constant temperature control device based on air bath according to Embodiment 1.

[0021] Figure 4 The side view of a constant temperature control device based on air bath according to Embodiment 1.

[0022] Figure 5 The top view of the turbulent flow fan and the rectifier in a constant temperature control device based on air bath according to Embodiment 1.

[0023] Figure 6 The cross-sectional view of the turbulent flow fan and the rectifier in a constant temperature control device based on air bath according to Embodiment 1.

[0024] Figure 7 The side sectional view of the turbulent flow fan and the rectifier in a constant temperature control device based on air bath according to Embodiment 1.

[0025] Figure 8 The longitudinal sectional view of the turbulent flow fan and the rectifier in a constant temperature control device based on air bath according to Embodiment 1.

[0026] Figure 9 The structural schematic diagram of a constant temperature control device based on air bath according to Embodiment 1.

[0027] Among them, there are a turbulent flow fan 1, a rectifier 2, an upper cover 3, a door state detection sensor 4, a lead pipe 5, a microfluidic chip sealing cover 6, an upper bracket 7, a toothed sealing ring 8, a heating cylinder 9, a carrier pressing ring bracket 10, a microfluidic chip carrier 11, a base 12, a middle bracket 13, a support pillar 14, a lower bracket 15, an anti-abrasion buckle 16, a support plate 17, a servo motor 18, a T-type thermocouple temperature sensor 19, a spoiler fan 20, a bracket 21, a limit spring 22, and a sealing plate 23. Specific implementation mode

[0028] To make the purpose, technical solutions, and advantages of the embodiments of this application clearer, the following will clearly and completely describe the technical solutions in the embodiments of this application in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are part of the embodiments of this application, rather than all of the embodiments.

[0029] Embodiment 1. Refer to Figures 1 to 9Description of this embodiment: A constant temperature control device based on air bath according to this embodiment includes: a turbulent flow fan 1, a rectifier 2, an upper cover 3, a door state detection sensor 4, a guiding pipe 5, a microfluidic chip sealing cover 6, an upper bracket 7, a toothed sealing ring 8, a heating cylinder 9, a carrier pressing ring bracket 10, a microfluidic chip carrier 11, a base 12, a middle bracket 13, a pillar 14, a lower bracket 15, an anti-abrasion buckle 16, a support plate 17, a servo motor 18, a T-type thermocouple temperature sensor 19, a turbulent flow fan 20, a bracket 21, a limiting spring 22, and a sealing plate 23. Between the turbulent flow fan 1 and the rectifier 2, relying on the clamping structure on the rectifier 2, the turbulent flow fan 1 and the rectifier 2 are tightly connected by four screws. Through calculation and measurement, it is obtained that the outlet diameter of the turbulent flow fan 1 is 1 mm smaller than the inlet diameter of the rectifier 2. The rectifier 2 is located above the upper cover 3. The outlet of the rectifier 2 and the inlet of the guiding pipe 5 are connected by two large-sized screws, and the screws pass through the guiding pipe 5 and are connected to the thread on the sealing plate 23 of the rectifier 2. The connection port between the guiding pipe 5 and the rectifier 2 and the upper cover 3 are respectively connected to the upper and lower sides of the sealing plate 23 in a glued form, ensuring the heat preservation of the entire machine. A limiting spring 22 is arranged between the upper cover 3 and the upper bracket 7, aiming to connect the whole machine, limit the position of the upper cover 3 at the same time, and prevent people from forgetting to close the upper cover 3. The upper cover 3 can automatically close slowly. The door state detection sensor 4 is installed on the front side of the upper cover 3, aiming to facilitate the machine to check whether the upper cover is closed and sealed properly. The upper cover 3 and the door state detection sensor 4 are connected in a bolt form. The microfluidic chip sealing cover 6 is located below the upper cover 3 and is installed on the microfluidic chip carrier 11, adopting a flange structure. The microfluidic chip sealing cover 6 is used to ensure the sealing characteristics in the nucleic acid amplification chamber, better protect the constant temperature in the nucleic acid amplification chamber, and prevent the influence of other external lights at the same time. There is a hot air hole in the middle of the microfluidic chip sealing cover 6. The hot air hole is circular, similar to the radius of the heating cylinder 9, so that the heating cylinder 9 passes through the hot air hole in the middle of the microfluidic chip sealing cover 6. The carrier pressing ring bracket 10 is installed on the inner ring of the microfluidic chip carrier 11, perpendicular to the inner ring of the microfluidic chip carrier 11. The diameter of the inner ring is the same as that of the microfluidic chip sealing cover. The microfluidic chip carrier 11 and the pressing ring bracket 10 are connected by a flange to form a whole, presenting a hollow cylindrical structure. The outer edge of the microfluidic chip carrier 11 is in a sealed state, and the bottom is in the shape of 6 fan-shaped heat dissipation holes, which is convenient for the turbulent flow fan 20 to evenly blow the hot air in the heating cylinder 9 to reach around the microfluidic chip, and is conducive to rapid temperature rise and fall. The microfluidic chip carrier 11 is installed above the base 12, and the calculated distance is 32 mm.The outer edge of the connection between the base 12 and the upper cover 3 is connected to the toothed sealing ring 8 by means of a coupling. The toothed sealing ring 8 is in the shape of a toothed hollow ring with a thickness of 8 mm. The microfluidic chip carrier 11 can be rotated by an external coupling, which facilitates the observation of the reaction process of the microfluidic chip by an external optical instrument, and at the same time plays a role in heat preservation and sealing. The turbulence fan 20 is installed 3 mm above the base 12. The servo motor 18 is directly connected to the turbulence fan 20. The servo motor 18 controls the speed of the turbulence fan 20 to control the temperature in the nucleic acid reaction chamber and the speed of temperature rise and fall. The base 12 is stacked and installed on the middle bracket 13. Four optical systems are designed on the bottom plane of the base 12 and are located on the same circumference. The outer diameter of the optical system is on the same circumference as the detection chamber on the microfluidic chip, which is convenient for observing fluorescence imaging during nucleic acid amplification, etc. Four T-type thermocouple temperature sensors 19 and four hot film anemometers are designed on the base 12 and are connected by a flange structure. The T-type thermocouple temperature sensors 19 are 90 degrees apart from each other and are inserted between the optical systems. The four hot film anemometers are also inserted between the optical systems. The four hot film anemometers are connected to the base by welding and are on the same horizontal plane and are vertically distributed on the surface of the base 12. The 90-degree angle installation is to better measure the temperature change in the nucleic acid detection chamber and avoid uneven temperature or non-compliance of the temperature in the nucleic acid detection chamber, which may seriously cause the heating wire and the servo motor 18 to burn out. The design of the surface of the middle bracket 13 is consistent with the shape and size of the base 12. The front side below the base 12 is installed with two of the struts 14 by screw threads, and the side rear is installed with two of the support plates 17 by screw threads. The support plates 17 are designed with a plurality of hollow rectangles to facilitate the wiring of the machine and the installation and debugging of other components. The bottoms of the struts 14 and the support plates 17 are connected to the lower bracket 15 by screw threads. Six anti-wear buckles are installed at the bottom of the lower bracket 15 to prevent wear and ensure stability during the transportation of the machine.

[0030] The interior of the heating cylinder 9 includes a heating wire and a heating wire skeleton, which provides a heat source for heating the nucleic acid amplifier. In this embodiment, the heating wire surrounds the outside of the heating wire skeleton. The heating wire skeleton is a cross-shaped heating coil made of mica sheet. The heating wire material includes but is not limited to Cr20Ni80 alloy electric heating wire. The turbulence fan 20 is a nine-blade right-angle fan blade centrifugal cooling fan. The fan material includes but is not limited to polyether ether ketone (PEEK). This material can withstand high temperatures up to 300 degrees and has good insulation performance and wear resistance. The hot air blown out from the heating cylinder 9 quickly flows to the turbulence fan 20 on the base 12. Driven by the servo motor 18, the turbulence fan 20 makes the hot air quickly gather near the nucleic acid detection chamber, quickly raises the temperature in the nucleic acid detection chamber, and synchronously adjusts the temperature in the nucleic acid detection chamber by changing the rotation speed of the turbulence fan 20 and the heating temperature of the heating cylinder 9. After calculation, the outer radius of the turbulence fan 20 is 25.07 mm, the inner radius is 24.07 mm, the fan blade height is 21.66 mm, and the radius of the base 12 is 74 mm, which are the optimal dimensions. The cylinder between the conduit 5 and the heating cylinder 9 is connected by a flange structure. The irregular wind output by the turbulence blower 1 is processed by the rectifier 2, and the rectifier 2 outputs regular wind. Among them, the interior of the rectifier 2 consists of four rectifying plates, a baffle plate, and two hot film anemometers. The double blades of the rectifying plate form an angle of 180 degrees, and the fan blade height is 32.47 mm. It is located 60 mm at the interface between the rectifier 2 and the turbulence blower 1. The rectifier 2 is rectangular, and each of its four sides is fixed with a rectifying plate by bolts with a length of 29.3 mm. The rectifying plate material includes but is not limited to polyether ether ketone (PEEK). This material can withstand high temperatures up to 300 degrees and has good insulation performance and wear resistance. The baffle plate is made of stainless steel wire mesh. This material can withstand high temperatures and can better filter the turbulent wind and the downwind. It is installed in a trapezoidal shape on the upper side inside the rectifier.The rectifying plate blades are fixed at an angle of 270 degrees. When the machine starts, the four rectifying plates cooperate with each other to organize the chaotic wind into regular wind. If the turbulent flow fan 1 blows too fast or the chaotic wind runs out through the rectifying plate, it will return to the rectifying plate through the baffle plate for re-organization. The regular wind will be guided by the baffle plate into the guiding pipe 5. There are two hot film anemometers, one behind the baffle plate and one at the air outlet. The hot film anemometer located behind the baffle plate is installed behind the baffle plate of the rectifier 2 and is connected perpendicularly to the upper plane of the rectifier 2 with bolts. The hot film anemometer at the air outlet is installed in the form of bolts, and the inclination angle is 125 degrees. This angle is measured to be the most suitable for detection accuracy and is more conducive to detecting the air flow after passing through the rectifier 2, ensuring that the air flow reaching the turbulent flow fan 20 meets the requirements of the nucleic acid detection chamber during the transmission process, avoiding too large or too small air flow being blown out. If the air flow is too large, it will form stagnant air between the turbulent flow fan 20 and the air in the heating cylinder 9, causing the turbulent flow fan 20 to not rotate and resulting in the burning of the servo motor 18. Seriously, it will cause the heating wire to continuously heat and burn out. If the output wind force of the turbulent flow fan 1 is too small, the air flow reaching the turbulent flow fan 20 will be too small, causing the air flow output from the heating cylinder 9 to be too small, resulting in uneven temperature and non-compliance with the temperature standard in the nucleic acid detection chamber.

[0031] When the hot film anemometer sensor in the rectifier 2 detects that the incoming air flow rate and the air flow rate detected in the base 12 are in a ratio of 1.5 to 1 cubic meters per second, it conforms to the normal air flow transmission of the machine. If the hot film anemometer sensor in the rectifier 2 detects that the air flow rate is too large, the turbulent flow fan 1 reduces its horsepower while the spoiler fan 20 is driven by the servo motor 18 to increase its rotational speed. The increased rotational speed is 1.45 times the excess air flow rate of the turbulent flow fan 1 and the heating cylinder 9 raises its temperature by more than 5 degrees above the normal temperature. If the hot film anemometer sensor in the rectifier 2 detects that the air flow rate is too small, the turbulent flow fan 1 increases its horsepower while the spoiler fan 20 is driven by the servo motor 18 to reduce its rotational speed. The reduced rotational speed is 0.85 times the lack of air flow rate of the turbulent flow fan 1 and the heating cylinder 9 raises its temperature by more than 8 degrees above the normal temperature. If the hot film anemometer sensor in the base 12 detects that the air flow rate is too small, the turbulent flow fan 1 increases its horsepower while the spoiler fan 20 is driven by the servo motor 18 to increase its rotational speed. The increased rotational speed is up to 0.5 times the lack of air flow rate of the turbulent flow fan 1 and the heating cylinder 9 raises its temperature by more than 10 degrees above the normal temperature. If the hot film anemometer sensor in the base 12 detects that the air flow rate is too large, the turbulent flow fan 1 reduces its horsepower while the spoiler fan 20 is driven by the servo motor 18 to increase its rotational speed. The increased rotational speed is up to 0.6 times the lack of air flow rate of the turbulent flow fan 1 and the heating cylinder 9 raises its temperature by more than 3 degrees above the normal temperature. The hot film anemometer sensor is used to detect the temperature in the nucleic acid amplification chamber to ensure that the air flow rate can achieve the uniformity of the temperature throughout the nucleic acid amplification chamber and has a fast and stable temperature rise and fall rate, and to avoid the occurrence of stagnant air between the heating cylinder 9 and the spoiler fan 20 or the burning of the heating wire in the heating cylinder 9 and the servo motor 18. The above are the values obtained through calculation and actual measurement, but are not limited to these values. If the size of the rectifier 2, the number and size of the rectifying plates, the baffle plates, etc. are changed, or the number of blades, the height of the blades, etc. of the spoiler fan 20 are changed, these values will all change.

[0032] Embodiment 2. A method for using a constant temperature control device based on air bath according to the present embodiment includes the following steps: Step 1. Sample and reagent preparation: Prepare the sample for nucleic acid detection of respiratory diseases to ensure that the collection process complies with the specifications. At the same time, prepare the supporting nucleic acid amplification reagents, including the primer-probe mixture (about 10 - 15 μL), the enzyme mixture (about 5 - 10 μL), and mix them with the extracted nucleic acid sample (about 5 - 10 μL) according to the requirements of the reagent instruction manual. The mixing process must strictly follow the relevant experimental specifications and be operated in a biosafety cabinet to avoid contamination. After completion, start to install the sample and reagent, carefully install the prepared mixed reagent and sample on the microfluidic chip carrier between the turbulent flow fan and the heating cylinder, pay attention to the accurate placement position, and avoid shaking or deviation that may affect the experimental results. Close the sealing cover to ensure that it is tightly closed, and then close the upper cover.

[0033] Step 2. After preparing the reagents, start the device. The door status detection sensor detects whether the upper cover is tightly closed. If not, it will give an alarm until the upper cover is tightly closed and then proceed to the next step. After the upper cover is tightly closed, the turbulent flow fan blows out chaotic air. The irregular air blown out by the turbulent flow fan enters the rectifier and is sorted out after passing through the four rectifying plates and the baffle plate in the rectifier, and then regular air is output. If irregular air appears behind the rectifying plate, it will be returned to the rectifying plate by the baffle plate for re-filtration until all the air passing through the rectifying plate is regular air, and the baffle plate guides it to the pipe connection. While outputting the regular air, the hot film anemometer respectively detects the air flow rate of the regular air behind the baffle plate and the air flow rate of the regular air about to enter the pipe to ensure that the air flow rate is within the specified range.

[0034] Step 3. The heating wire in the heating cylinder rapidly increases the temperature, rapidly rising to the temperature required in the detection chamber. The regular air entering from the pipe passes through the heating cylinder, and at this time, the output air is regular hot air with a certain temperature. The heating wire in the heating cylinder changes the temperature according to the temperature requirements in the nucleic acid detection chamber. Taking 120 temperature cycles as a period, when the heating wire lights up and shows red, it is in the heating state; when the brightness of the heating wire decreases, it is in the cooling state. The air flowing out of the heating cylinder is directly above the turbulent flow fan.

[0035] Step 4. The hot film anemometer installed above the base detects whether the temperature transmitted from the heating cylinder meets the nucleic acid amplification temperature.

[0036] If it meets the requirement, the servo motor drives the turbulent flow fan to rotate stably, so that the hot air flowing out of the heating cylinder is blown to the entire device surrounding the surface of the microfluidic chip to make the reaction sufficient; If not, the servo motor controls the spoiler fan to rotate. When the hot film anemometer sensor detects that the air flow rate is too small, the turbulent flow fan increases its horsepower while the spoiler fan is driven by the servo motor to increase its rotational speed. The increased rotational speed is up to 0.5 times the lack of air flow rate of the turbulent flow fan and the temperature of the heating cylinder rises by more than 10 degrees above the normal temperature. If the hot film anemometer sensor detects that the air flow rate is too large, the turbulent flow fan reduces its horsepower while the spoiler fan is driven by the servo motor to increase its rotational speed. The increased rotational speed is up to 0.6 times the lack of air flow rate of the turbulent flow fan and the temperature of the heating cylinder rises by more than 3 degrees above the normal temperature.

[0037] Step Five: When the temperature in the nucleic acid amplification chamber meets the requirements and is balanced, the servo motor drives the spoiler fan to rotate stably at this time, so that the hot air flowing out of the heating cylinder is blown around the entire nucleic acid amplification device and surrounds all parts of the surface of the microfluidic chip, enabling the nucleic acid amplification reaction to proceed fully.

[0038] Step Six: According to the specific requirements of the nucleic acid amplification experiment, the rotational speed of the spoiler fan is adjusted through the servo motor, and at the same time, the temperature of the heating wire in the heating cylinder is adjusted, so as to achieve the effect of precise temperature increase and decrease, ensuring that the nucleic acid amplification chamber reaches the temperature required for the experiment. During the adjustment process, the four-way optical system and the four T-type thermocouple temperature sensors evenly designed on the surface of the base can be used to observe and test the changes in the nucleic acid amplification chamber in real time, providing a basis for temperature adjustment and ensuring the uniformity of the nucleic acid amplification reaction.

[0039] Step Seven: After the nucleic acid amplification experiment is completed, first turn off the power of the device. Carefully take out the sample on the carrier rack and properly dispose of the sample and experimental waste according to the laboratory regulations. For example, the waste after detecting virus samples needs to be processed according to the medical waste treatment process, and after high-pressure sterilization or special chemical disinfection treatment, subsequent disposal can be carried out. After that, clean and maintain the nucleic acid amplifier for the next use.

[0040] Those skilled in the art can understand that the above description is only the preferred embodiment of the present invention. The features described in each embodiment and / or claim of the present disclosure can be combined or combined in various ways, even if such combinations or combinations are not explicitly recorded in the present disclosure. It is not used to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

[0041] Although the preferred embodiments of the present invention have been described, additional changes and modifications can be made to these embodiments by those skilled in the art once they learn the basic inventive concept. Therefore, the appended claims are intended to be construed to include the preferred embodiments as well as all changes and modifications that fall within the scope of the present invention. Obviously, those skilled in the art can make various changes and variations to the present invention without departing from the spirit and scope of the present invention. Thus, if these modifications and variations of the present invention fall within the scope of the claims of the present invention and their equivalent technologies, the present invention is also intended to include these modifications and variations.

Claims

1. A constant temperature control device based on air bath, characterized in that, The device includes a turbulent flow fan (1), a rectifier (2), a guiding pipe (5), a heating cylinder (9), a microfluidic chip carrier (11), a base (12), a turbulent flow fan (20), a servo motor (18), a sealing plate (23), an upper cover (3) and a bracket (21); The turbulent flow fan (1) is connected to the rectifier (2), and the rectifier (2) and the guiding pipe (5) are fixed by threaded connection on the sealing plate (23) through bolts; the guiding pipe (5) wraps the heating cylinder (9) for firm connection. The turbulent flow fan (20) is installed on the base (12), and the servo motor (18) is directly connected to the turbulent flow fan (20). The servo motor (18) drives the turbulent flow fan (20) to rotate. The heating cylinder (9) is vertically above the microfluidic chip carrier (11).

2. The constant temperature control device based on air bath according to claim 1, characterized in that, The device further includes a baffle plate. The baffle plate is trapezoidal and is installed on the upper side inside the rectifier (2). The baffle plate is connected to the rectifier (2) by welding.

3. The constant temperature control device based on air bath according to claim 1, characterized in that, The device further includes a rectifying plate. The rectifying plate is in the shape of a wing-shaped double-leaf fan blade and is used to adjust the form of the air blown by the turbulent flow fan (1). Four rectifying plates form a rectifying body.

4. The constant temperature control device based on air bath according to claim 1, characterized in that, The device further includes hot film anemometers. Two hot film anemometers are provided on the rectifier (2), and four hot film anemometers are provided on the base (12) to detect the air flow rate after the air input by the turbulent flow fan (1) is rectified by the rectifier (2) and the remaining air flow rate at the bottom after passing through the guiding pipe (5) and the heating cylinder (9).

5. The constant temperature control device based on air bath according to claim 1, characterized in that, The device further includes a carrier retaining ring bracket (10) and a microfluidic chip sealing cover (6). The microfluidic chip sealing cover (6) is located below the upper cover (3) and is installed on the microfluidic chip carrier (11). A flange structure is used to connect with the microfluidic chip sealing cover (6).

6. The constant temperature control device based on air bath according to claim 1, characterized in that, The device further includes a toothed sealing ring (8). The outer edge of the connection between the base (12) and the upper cover (3) is connected with the toothed sealing ring (8) by means of a coupling. The toothed sealing ring (8) is in the shape of a toothed hollow ring with a thickness of 8 mm. The microfluidic chip carrier (11) is rotated through the coupling.

7. The constant temperature control device based on air bath according to claim 1, characterized in that, The heating cylinder (9) includes a heating wire and a heating wire skeleton. The heating wire skeleton is a cross-shaped skeleton, and the heating wire is wound around the outer surface of the heating wire skeleton.

8. The constant temperature control device based on air bath according to claim 1, characterized in that, The turbulent flow fan (20) is a nine-leaf right-angle fan blade centrifugal cooling fan.

9. The constant temperature control device based on air bath according to claim 4, characterized in that, Four optical systems and four T-type thermocouple temperature sensors (19) are further provided on the surface of the base (12). The four T-type thermocouple temperature sensors (19) are 90 degrees apart. The four hot film anemometers provided on the base (12) are simultaneously inserted between the T-type thermocouple temperature sensors and the four optical systems.

10. A control method for a constant temperature control device based on air bath, the control method is implemented based on a constant temperature control device according to any one of claims 1-9, characterized in that, The control method is realized by a nucleic acid amplification experiment. The control method includes the following steps: Step 1: Install the prepared mixed reagent and sample on the microfluidic chip carrier (11) between the turbulent flow fan (20) and the heating cylinder (9); Step 2: Start the device. Use the door status detection sensor (4) to detect whether the upper cover (3) is tightly closed. If it is not, an alarm will be issued until the upper cover (3) is tightly closed, and then proceed to Step 3. The irregular wind blown out by the turbulent flow fan (1) enters the rectifier (2). After being sorted by the four rectifying plates and the baffle plate in the rectifier (2), regular wind is output. If irregular wind appears behind the rectifying plate, it will be returned to the rectifying plate by the baffle plate for re-filtration until all the wind passing through the rectifying plate is regular wind. The baffle plate guides it to the connection of the guiding pipe (5). Step 3: The heating wire in the heating cylinder (9) rapidly heats up to the required temperature in the detection chamber, and the regular wind entering from the guiding pipe (5) passes through the heating cylinder (9). The heating wire in the heating cylinder (9) changes its temperature according to the temperature requirement in the nucleic acid detection chamber. Taking 120 temperature cycles as a period, when the heating wire lights up and appears red, it is in the heating-up state; when the brightness of the heating wire decreases, it is in the cooling state. Step 4: The hot film anemometer installed above the base (12) detects whether the temperature transmitted from the heating cylinder (9) meets the nucleic acid amplification temperature. If it meets the requirement, the servo motor (18) drives the turbulent flow fan (20) to rotate stably, so that the hot air flowing out from the heating cylinder (9) is blown to the whole device surrounding the surface of the microfluidic chip to make the reaction sufficient. If it does not meet the requirement, the servo motor (18) controls the rotation of the turbulent flow fan (20). When the hot film anemometer detects that the air flow rate is too small, the increased rotation speed is 0.5 times the lack of air flow rate of the turbulent flow fan (1) and the temperature of the heating cylinder (9) rises by more than 10 degrees above the normal temperature; if the hot film anemometer detects that the air flow rate is too large, the increased rotation speed is 0.6 times the lack of air flow rate of the turbulent flow fan (1) and the temperature of the heating cylinder (9) rises by more than 3 degrees above the normal temperature. Step 5: Adjust the rotation speed of the turbulent flow fan (20) through the servo motor (18), and at the same time adjust the temperature of the heating wire in the heating cylinder (9) to complete the constant temperature control of the air bath.

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