阅读说明：本技术 一种平面细胞的加载装置及气动控制方法 (Planar cell loading device and pneumatic control method ) 是由 夏明一 周成波 徐振邦 于 2021-07-29 设计创作，主要内容包括：本发明提供一种平面细胞的加载装置及气动控制方法,包括从上到下依次布置的透明盖、培养板、加载板和加载底座；培养板设有细胞培养孔,细胞培养孔在孔底设置加载膜用以承载细胞,细胞培养孔通过透明盖与外部环境隔绝；加载底座为顶部具有开口的腔体；培养板封装腔体形成气室；腔体的内部设有加载板；加载板设有位于加载膜的下方的加载台,加载台遮挡部分的加载膜,气室经过加载板上的通孔为加载膜提供压力。本发明通过将加载膜安装在细胞培养孔上,便于单独更换加载膜；结构简单也便于更换加载台。(The invention provides a loading device and a pneumatic control method for planar cells, which comprises a transparent cover, a culture plate, a loading plate and a loading base which are sequentially arranged from top to bottom; the culture plate is provided with a cell culture hole, a loading membrane is arranged at the bottom of the cell culture hole for bearing cells, and the cell culture hole is isolated from the external environment through a transparent cover; the loading base is a cavity with an opening at the top; the culture plate is sealed with the cavity to form an air chamber; a loading plate is arranged in the cavity; the loading plate is provided with a loading platform positioned below the loading membrane, the loading platform shields part of the loading membrane, and the air chamber provides pressure for the loading membrane through the through hole on the loading plate. According to the invention, the loading membrane is arranged on the cell culture hole, so that the loading membrane can be conveniently and independently replaced; simple structure also is convenient for change loading platform.)

1. A loading device for plane cells is characterized by comprising a transparent cover (11), a culture plate (12), a loading plate (14) and a loading base (15) which are arranged from top to bottom in sequence;

the culture plate (12) is provided with at least one cell culture hole (122);

the cell culture well (122) comprises a loading membrane (124) arranged at the bottom of the well, the loading membrane (124) is used for loading cells, and the cell culture well (122) is isolated from the external environment through the transparent cover (11);

the loading base (15) is a cavity with an opening at the top, and the culture plate (12) encapsulates the cavity to enable the cavity to form an air chamber;

the loading plate (14) is arranged in the cavity, and the loading plate (14) is provided with a through hole for allowing the gas in the gas chamber to pass through;

the upper part of the loading plate (14) is provided with a loading platform which is positioned below the loading film (124), and the loading platform does not completely shade the loading film (124), so that the loading film (124) is subjected to plane force when being loaded.

2. The planar cell loading device according to claim 1, wherein the loading base (15) is provided with a gas chamber boss (151) extending toward the inside of the cavity, and the loading plate (14) is overlapped on the gas chamber boss (151).

3. The planar cell loading device according to claim 2, wherein said loading device is provided with two loading plates (14) which are respectively provided as a first loading plate (141) and a second loading plate (142), and said first loading plate (141) and said second loading plate (142) are alternatively connected with said loading base (15);

the pore wall of the cell culture pore (122) extends towards the lower part of the loading membrane (124) to form a dome space below the loading membrane (124);

the loading platform of the first loading plate (141) is a cylinder and is arranged in the dome space, the diameter of the cylinder is smaller than that of the loading membrane (124), so that the loading membrane (124) is stressed in two dimensions;

the loading table of the second type loading plate (142) is in the shape of a long strip and is arranged in the dome space, and the long strip is arranged along the radial direction of the loading film (124), so that the loading film (124) is stressed in one dimension.

4. The planar cell loading device according to claim 1, wherein the wall of the cell culture well (122) extends to the lower part of the loading membrane (124) to form a dome space below the loading membrane (124);

the loading platform is a cylinder and is arranged in the dome space, and the diameter of the loading platform is smaller than that of the loading film (124); subjecting the loaded membrane (124) to a two-dimensional force.

5. The planar cell loading device according to claim 1, wherein the wall of the cell culture well (122) extends to the lower part of the loading membrane (124) to form a dome space below the loading membrane (124);

the loading platform is in a long strip shape and is arranged in the space of the round cover, and the long strip shape is arranged along the radial direction of the loading film (124), so that the loading film (124) is stressed in one dimension.

6. The planar cell loading device according to claim 1, further comprising a sealing ring (13) disposed between the culture plate (12) and the loading base (15);

a sealing boss surrounding the sealing ring (13) is arranged at the top of the loading base (15);

the cross section of the sealing ring (13) is L-shaped, so that the sealing ring (13) is clamped between the bottom surface of the culture plate (12) and the top surface of the loading base (15), and is clamped between the outer surface of the culture plate (12) and the inner wall surface of the sealing boss.

7. The planar cell loading device according to claim 1, wherein the through hole is provided at the edge of the loading plate (14).

8. The planar cell loading device according to claim 1, wherein the culture plate (12) comprises an outer frame and the cell culture holes (122) fixed in the outer frame, the outer frame has a rectangular frame structure, and the transparent cover (11) is sleeved on the top of the culture plate (12);

and a culture plate chamfer (121) is arranged between two side faces of the outer frame, and a transparent cover chamfer (111) matched with the culture plate chamfer (121) is arranged on the transparent cover (11).

9. The planar cell loading device according to claim 1, further comprising a pneumatic system, wherein the pneumatic system comprises a pneumatic device (61), a pressure sensor (62) and a controller (63);

the cavity of the loading base (15) is connected with a positive pressure pump connecting port (153) and a negative pressure pump connecting port (155) in parallel;

the pneumatic device (61) comprises a negative pressure pump (615), a negative pressure filter (614), a negative pressure stabilizing bottle (613), a negative pressure flow valve (612) and a negative pressure electromagnetic valve (611) which are connected in sequence, and the negative pressure electromagnetic valve (611) is connected with the negative pressure pump connecting port (155);

the pneumatic device (61) further comprises a positive pressure pump (616), a positive pressure filter (617), a positive pressure stabilizing bottle (618), a positive pressure flow valve (619) and a positive pressure electromagnetic valve (620) which are sequentially connected, and the positive pressure electromagnetic valve (620) is connected with the positive pressure pump connecting port (153);

the pressure sensor (62) is used for monitoring a pressure value in the cavity of the loading base (15) and converting the pressure value into an electric signal to be transmitted to the controller (63);

the controller (63) is respectively electrically connected with the negative pressure flow valve (612), the negative pressure electromagnetic valve (611), the positive pressure flow valve (619) and the positive pressure electromagnetic valve (620).

10. A method of pneumatic system control by the pneumatic system of claim 9, comprising the steps of:

a1, starting the pneumatic system, inputting a required pressure waveform from initial time to termination time, averagely dividing the initial time to the termination time into a plurality of time periods according to a preset width value, and setting a target pressure for each time period, wherein the target pressure is used for fitting the pressure of the corresponding waveform in the time period; the controller (63) converting the value of the target pressure into an electrical signal;

a2, the controller (63) judges whether the target pressure in the current time period is increased or reduced compared with the target pressure in the last time period; if the current time period is the first time period, judging whether the target pressure in the current time period is increased or reduced compared with the pressure of 0 value;

a3, if the pressure is increased, closing the negative pressure electromagnetic valve (611) and the negative pressure flow valve (612), and opening the positive pressure electromagnetic valve (620) and the positive pressure flow valve (619); if the pressure is reduced, closing the positive pressure electromagnetic valve (120) and the positive pressure flow valve (619), and opening the negative pressure electromagnetic valve (611) and the negative pressure flow valve (612);

a4, according to the judgement result of the step A3 or the step A7, adjusting the opening of the corresponding positive pressure flow valve (619) or negative pressure flow valve (612) as required to adjust the pressure in the cavity of the loading base (15);

a5, the controller (63) judges whether the current time is the termination time, if yes, the step A8 is executed; if not, executing the step A6;

a6, the controller (63) executes the next time period, whether the target pressure of the current time period and the target pressure of the time period of the step A5 are changed or not is judged, and if yes, the step A2 is executed; if not, executing the step A7;

a7, the controller (63) receiving the electric signal from the pressure sensor (62), comparing with the target pressure converted electric signal for the time period in the step A6, if the absolute value of the difference is less than or equal to a predetermined error, executing the step A5;

if the difference is smaller than zero and the absolute value of the difference is larger than a preset error, judging that the pressure is increased, closing the negative pressure electromagnetic valve (611) and the negative pressure flow valve (612), opening the positive pressure electromagnetic valve (620) and the positive pressure flow valve (619), and executing the step A4;

if the difference is greater than zero and the absolute value of the difference is greater than a preset error, determining that the pressure is reduced, closing the positive pressure electromagnetic valve (620) and the positive pressure flow valve (619), opening the negative pressure electromagnetic valve (611) and the negative pressure flow valve (612), and executing the step A4;

a8, unloading the pressure in the loading base (15).

Technical Field

The invention relates to the field of cell mechanics, in particular to a loading device and a pneumatic control method for planar cells.

Background

The study of various cellular responses in vivo is currently a direction of greater interest in biology. Due to the complex in vivo environment, in vivo cell mechanics experiments are difficult to distinguish the effect of mechanical factors and other factors on cells, such as the influence of hydrostatic pressure, fluid shear stress, current, biochemical environment and other factors. The existing scientific research personnel have the technical problem of interference of other factors when carrying out in-vivo cell mechanics experiments, and the key point for researching cell mechanics is to find a proper cell mechanics loading method and device.

Therefore, it is desirable to provide a loading device for planar cells to solve the above problems.

Disclosure of Invention

The present invention provides a loading device for planar cells to solve the above problems.

In order to provide mechanical loading in a plane for cells to simulate the single stress condition in vivo, the invention adopts the following specific technical scheme:

a loading device for planar cells comprises a transparent cover, a culture plate, a loading plate and a loading base which are sequentially arranged from top to bottom;

the culture plate is provided with at least one cell culture hole;

the cell culture well comprises a loading membrane arranged at the bottom of the well, the loading membrane is used for loading cells, and the cell culture well is isolated from the external environment through the transparent cover;

the loading base is a cavity with an opening at the top, and the culture plate encapsulates the cavity to enable the cavity to form an air chamber;

the loading plate is arranged in the cavity and is provided with a through hole for allowing the gas in the gas chamber to pass through;

the upper part of the loading plate is provided with a loading platform, the loading platform is positioned below the loading film, and the loading platform does not completely shield the loading film, so that the loading film is subjected to a plane force during loading.

The invention can obtain the following technical effects:

the culture plate of the loading device for the plane force cells provided by the invention is provided with a plurality of cell culture holes, and the loading membrane is integrated in the cell culture holes, so that compared with the prior art in which a whole loading membrane is used for separating the loading plate from the culture plate, the loading membrane can be conveniently and independently replaced according to the requirement; the loading plate only needs to be placed on the loading base, in other words, the loading plate and the loading base are movably disassembled, so that different types of loading plates can be conveniently replaced, and the mechanical loading in two directions in a plane can be realized; the device has small integral volume and compact and simple structure, and reduces the production cost. In addition, the device can be put into a cell constant temperature incubator for use, so that the cell culture with dynamic mechanical loading has feasibility.

Drawings

Fig. 1 is a schematic structural diagram of a loading device according to an embodiment of the present invention;

fig. 2 is an exploded view of a loading device according to an embodiment of the present invention;

FIG. 3 is a schematic diagram illustrating a pre-operation state of a first loading plate according to an embodiment of the present invention;

FIG. 4 is a schematic diagram illustrating a first loading plate according to an embodiment of the present invention in an operating state;

FIG. 5 is a top view diagram of a first load plate in operation according to an embodiment of the present invention;

FIG. 6 is a top view diagram of a second load plate in operation according to an embodiment of the present invention;

FIG. 7 is a schematic structural diagram of a transparent cover provided in an embodiment of the present invention;

FIG. 8 is a schematic front view of a culture plate according to an embodiment of the present invention;

FIG. 9 is a schematic view of the reverse structure of a culture plate according to an embodiment of the present invention;

FIG. 10 is a schematic structural diagram of a seal ring provided in accordance with an embodiment of the present invention;

FIG. 11 is a schematic structural diagram of a first loading plate according to an embodiment of the present invention;

FIG. 12 is a schematic structural diagram of a second loading plate provided in an embodiment of the present invention;

FIG. 13 is a schematic diagram of a front structure of a loading base according to an embodiment of the present invention;

FIG. 14 is a schematic view of the bottom structure of an end cap according to an embodiment of the present invention;

FIG. 15 is a schematic diagram of a pneumatic system provided by an embodiment of the present invention;

fig. 16 is a flowchart illustrating a control method of a pneumatic system according to an embodiment of the present invention.

Wherein the reference numerals include:

11. a transparent cover; 12. culturing the plate; 13. a seal ring; 14. a loading plate; 15. loading a base;

111. chamfering the transparent cover;

121. chamfering the culture plate; 122. a cell culture well; 123. a rib plate on the front surface of the culture plate; 124. loading a film; 125. culturing a plate boss; 126. the rib plate on the back side of the culture plate;

131. an inner ring step; 132. the bottom of the sealing ring;

141. a first load plate; 142. a second load plate;

151. a boss of the air chamber; 152. a sealing ring mounting surface; 153. a positive pressure pump connection port; 154. a pressure sensor connector; 155. a negative pressure pump connector; 156. a clamping tool mounting groove 1411 and a first loading platform; 1412. a first grasping port; 1413. hollowing out; 1421. a second loading table; 1422. a second grasping port;

61. a pneumatic device; 62. a pressure sensor; 63. a controller; 64. a cell loading device; 611. a negative pressure solenoid valve; 612. a negative pressure flow valve; 613. a negative pressure stabilizing bottle; 614. a negative pressure filter; 615. a negative pressure pump; 616. a positive pressure pump; 617. a positive pressure filter; 618. a positive pressure stabilizing bottle; 619. a positive pressure flow valve; 620. a positive pressure solenoid valve.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be described in further detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not to be construed as limiting the invention.

A loading device for planar cells as shown in FIGS. 1-2 mainly comprises a loading plate 14, a transparent cover 11 for isolating from the external environment, a culture plate 12 for cell culture, and a loading base 15 for providing support and air chamber, which are arranged in sequence from top to bottom. As shown in FIG. 1, assume that the x-axis is oriented in a first direction, the y-axis is oriented in a second direction, and the z-axis is orthogonal to the x-axis and the y-axis. The plate 12 may be provided with six cell culture wells 122, as described herein, and multiple wells may facilitate multiple experiments simultaneously.

Wherein the cell culture wells 122 are used for carrying cells by arranging a loading membrane 124 at the bottom of the wells, and the cell culture wells 122 in the culture plate 12 are 6 separate cell culture chambers in which the cells are cultured. The cell culture hole 122 is a hollow cylinder with a top and a bottom removed, the inner wall surface of the cylinder is fixedly connected with an annular culture plate boss 125, the culture plate boss 125 extends to the radial inner part of the cylinder, the function of the culture plate boss 125 is to fix the loading membrane 124 on the cell culture hole 122, and the loading membrane 124 forms a seal with the periphery of the cell culture hole 122 positioned at the upper part of the culture plate boss 125. The loading membrane 124 on the plane of the projection 125 of the culture plate divides the wall of the cell culture well 122 into two parts, and the cell culture well 122 and the loading membrane 124 on the lower part of the projection 125 of the culture plate form a dome space which can be sleeved on the top of the loading table to facilitate the positioning of the loading table. The front rib 123 and the back rib 126 of the culture plate 12 are connected between the cell culture holes 122 and between the cell culture holes and the outer frame, so that no gas passes through the thickness of the culture plate 12, the structural strength is increased, the transparent cover and the loading base are separated by the culture plate, and when the culture plate is placed on the loading base 15, an air chamber is formed and used for receiving pressure.

As shown in FIGS. 7 to 9, the outer frame of the culture plate 12 has a cross section of a generally shell-like rectangular parallelepiped surrounding the six cell culture wells 122, and the transparent cover 11 has a bottom surface of a shell-like rectangular parallelepiped having an opening. The transparent cover 11 is sleeved on the top of the culture plate 12, when the culture plate is used, the transparent cover is pressed to the culture plate by using a clamping tool in the field, the culture plate is pressed, the transparent cover is in contact connection with the culture plate, the transparent cover and the culture plate do not shift relatively, and sealing is not needed between the transparent cover and the culture plate.

Preferably, the plate 12 includes an outer frame, and the cell culture wells 122 are fixedly attached to the inside of the outer frame. The shape of the transparent cover 11 is matched with the shape of the outer frame of the culture plate 12, and the transparent cover 11 is buckled on the culture plate 12 when in use to ensure that the culture plate 12 is isolated from the external environment. The present disclosure will be described by taking an example in which the outer frame is a rectangular frame having a rectangular parallelepiped shape with a through hole in the height direction.

Preferably, a plate chamfer 121 is provided between two sides of the outer frame of the plate 12, i.e. a vertically placed side of the outer frame is chamfered. Similarly, a transparent cover chamfer 111 is arranged at the corresponding position of the transparent cover 11, so that one corner of the four corners of the culture plate 12 and the transparent cover 11 is cut off. The culture plate chamfer 121 is matched with the transparent cover chamfer 111, so that the transparent cover cannot move in the horizontal plane, and the transparent cover plays roles in blocking environmental pollution and protecting cells.

Preferably, the outer frame of the culture plate 12 has an L-shaped cross section in the vertical plane, and a step surface is formed on the outer frame to facilitate the overlapping of the bottom surface of the transparent cover 11 on the step surface, thereby further protecting the culture plate.

As shown in fig. 13-14, the loading base 15 is a cavity with an opening at the top for providing support and air space. The loading base 15 is a hollow cuboid, and the culture plate 12 encapsulates a cavity.

Preferably, the culture plate 12 is connected to the loading base 15 in a sealing manner by a sealing ring 13. The cross-sectional shape of the seal ring 13 is L-shaped, and an inner ring step 131 is formed inside the seal ring. The bottom surface of the culture plate 12 is matched with the inner ring step 131 of the sealing ring 13 to play a role of sealing; the sealing ring mounting surface 152 of the loading base 15 cooperates with the sealing ring bottom 132 of the sealing ring 13 to provide sealing. More specifically, the top of the loading base 15, i.e., the seal ring mounting surface 152, is provided with a ring of seal bosses. As shown in FIG. 10, the cross-sectional shape of the seal ring 13 is L-shaped, the inner wall surface of the seal ring surrounds the outer surface and the bottom surface of the culture plate, the inner wall surface of the seal boss surrounds the outer wall surface of the seal ring, and the bottom surface of the seal ring is lapped on the load base. So that the packing 13 is sandwiched between the bottom surface of the culture plate 12 and the top surface of the loading base 15, and between the outer surface of the culture plate 12 and the inner wall surface of the seal projection.

The loading plate 14 is a flat plate having loading stages corresponding to the number of the cell culture wells 122 protruded from the upper portion thereof, and is disposed inside the loading base. The loading plate 14 is provided with a loading stage located below the loading film 124. The loading station does not completely obscure the loading film 124 such that only a portion of the loading film 124 is in contact with the loading station. The air chamber provides negative pressure for the culture plate 12 through the through hole on the loading plate 14, the transparent cover 11 is pressed downwards through a clamping tool commonly used in the field, so that the transparent cover 11 is tightly contacted with the culture plate 12, and the cell culture hole 122 is also tightly contacted with the transparent cover 11 without additional sealing. The shape of the load table is known in the art and preferably includes a first load plate and a second load plate as described below with respect to fig. 3-4. The loading platform is used for constructing a stress condition for the cell stress for loading the membrane.

Preferably, the loading base 15 is provided with an air chamber boss 151 extending toward the inside of the cavity, and the loading plate 14 is movably overlapped on the air chamber boss 151. The air chamber bosses 151 may be provided on a pair of inner wall surfaces of the loading base which are arranged oppositely. The top surface of the air chamber boss 151 is fitted with the bottom surface of the loading plate 14, the periphery of the loading plate is fitted with the periphery of the loading base to play a positioning role, and in addition, the air chamber boss 151 raises the loading plate 14 so as not to contact with the lowest surface of the loading base, thereby forming an air passage. When the loading plate 14 is disassembled, the clamping tool is loosened, so that the transparent cover 11 and the culture plate 12 have no pressing force and are disconnected, the transparent cover 11 and the culture plate 12 can be taken down, and finally the clamping tool can be placed at the through hole on the loading plate 14 by hand so as to be convenient for taking out the loading plate. This facilitates replacement of load plates 14 for different configurations of load stations.

Wherein, the loading plate 14 is provided with a through hole for facilitating the gas in the gas chamber to pass through the loading plate and be pressurized on the loading membrane.

Preferably, the through hole is formed at the edge of the loading plate 14, that is, a part of one edge of the loading plate 14 is removed due to the through hole, so that the through hole not only has a ventilation function, but also can be conveniently held by hand to separate the loading plate from the loading base.

In a preferred embodiment of the present invention, as shown in fig. 3 to 4 and fig. 11 to 12, the loading device is provided with two loading plates 14, which are respectively provided as a first loading plate 141 and a second loading plate 142, and the first loading plate 141 and the second loading plate 142 are alternatively connected to the loading base 15.

The loading platform of the first loading plate 141 is a cylinder which is sleeved in the round cover space, and the diameter of the cylinder is smaller than that of the loading film 124, so that the loading film 124 bears two-dimensional force; the diameter of the cylindrical body is smaller than the inner diameter of the plate boss 125.

Here, the loading table of the second type loading plate 142 is an elongated shape placed in the radial direction of the loading film 124, so that the loading film 124 is subjected to a one-dimensional force. Preferably, the width of the loading platform is smaller than the diameter of the loading membrane, so that two sides of the loading membrane are not contacted with the loading platform; the loading platform is placed at the diameter of the loading membrane passing through the circle center, so that the middle part of the loading platform is in contact with the loading membrane; the loading membrane 124 and the wall of the culture well 122 form a dome space with a downward opening, and the two ends of the loading platform in the length direction are arc surfaces matching the shape of the dome space. The loading table and the dome are in interference fit in space, so that gas is prevented from entering the loading film 124 from two arc surfaces of the loading table.

The two kinds of load plates 14 include a first load plate 141 and a second load plate 142. The first grabbing port 1412 and the second grabbing port 1422 on the first loading plate 141 and the second loading plate 142 are arc-shaped, so that the two loading plates 14 can be conveniently taken out of the loading base 15, more importantly, a smooth air passage is provided for the device, and the grabbing ports of the two loading plates are provided with rounded corners, so as to prevent hands from being scratched by sharp corners during operation; the first 1411 and second 1421 load stations of both load plates 14 are located in close proximity to the load membrane 124 of the growth plate 12, which may be considered to be in contact but not generating force; the hollow 1413 of the first loading plate 141 is for reducing the material consumption of the first loading plate 141, and the hollow of the second loading plate 142 is not provided because the loading platform has a special shape and the cost of the hollow is high. When the device starts to be loaded, the loading membrane 124 is pressed against the top surface of the first loading stage 141 and the top surface of the second loading stage, and the loading membrane 124 is subjected to tensile deformation, so that the cells on the loading membrane are subjected to strain force.

Preferably, the loading device further comprises a pneumatic system, see fig. 15-16, as shown, the pneumatic system for cell loading comprising: a pneumatic device 61 for adjusting the pressure in the cell loading device, a pressure sensor 62 for monitoring the pressure in the cell loading device in real time, and a controller 63 for receiving, processing and sending signals.

The pneumatic device 61 is connected to the loading base 15, and includes a negative pressure pump 615, a negative pressure filter 614, a negative pressure stabilizing bottle 613, a negative pressure flow valve 612, and a negative pressure solenoid valve 611, which are connected in sequence by a pipe joint and a gas pipe, and the negative pressure solenoid valve 611 is connected to the negative pressure pump connection port 155.

The pneumatic device 61 further comprises a positive pressure pump 616, a positive pressure filter 617, a positive pressure stabilizer 618, a positive pressure flow valve 619 and a positive pressure solenoid valve 620 which are sequentially connected by a pipe joint and a gas pipe, wherein the positive pressure solenoid valve 620 is connected with the positive pressure pump connecting port 153.

The positive pressure pump connection port 153 and the negative pressure pump connection port 155 of the cell loading device are respectively connected with the positive pressure electromagnetic valve and the negative pressure electromagnetic valve through pipe joints and air pipes.

The positive pressure pump 616 and the negative pressure pump 615 are air sources, the pneumatic device 61 provides a required power source by the air sources, pure, dry and stable air flow is obtained from the air flow in the air sources through a filter and a pressure stabilizing bottle, then the air flow is adjusted through a flow valve and a solenoid valve to obtain air flow with required flow, and finally the air flow enters the loading base 15. The air from the positive pressure pump or the negative pressure pump firstly passes through the corresponding filter and then enters the corresponding pressure stabilizing bottle, so that moisture and impurities in the air are prevented from being accumulated in the pressure stabilizing bottle; the solenoid valves connected in sequence are closer to the loading base 15 than the flow valves because: the electromagnetic valve is used for opening or cutting off the air path, the flow valve is used for adjusting the size of the opening of the air path, and when the electromagnetic valve is closed, any action of the flow valve has no influence on the pressure in the loading base 15.

The pressure sensor 62 is connected to a pressure sensor connection port 154 of the loading base 15, and can monitor the pressure inside the loading base 15 in real time and convert the pressure into an electrical signal to be transmitted to the controller 63.

The controller 63 is connected to two flow valves, two solenoid valves and also to the pressure sensor 62. The controller 63 receives the electric signal from the pressure sensor 62, processes the waveform of the target pressure and converts it into a corresponding electric signal, and transmits a control signal to the flow valve and the solenoid valve in the pneumatic device 61.

The pneumatic device can adjust the pressure intensity in the loading base 15 to pressurize, decompress and pressure-maintaining the loading device. The control method monitors the pressure in the cell loading device at any time and feeds the pressure back to the controller, error compensation is added compared with open-loop control, so that the control precision is higher, pressure relief operation is carried out on the cell loading device before the system finishes working, the device cannot be operated under pressure, and the safety and the reliability of the system during experiment are ensured.

A method of controlling a pneumatic system for cell loading, as shown in fig. 16, comprising the steps of:

A1、

s10, starting a pneumatic system;

s20, inputting a waveform of the required pressure within the time from the initial time to the ending time, uniformly dividing the time from the initial time to the ending time into a plurality of time periods according to a preset width value, setting a target pressure for each time period by the controller 13, wherein the target pressure is used for fitting the pressure corresponding to the time period; for example, the desired pressure waveform is a sine curve, the waveform is sequentially divided equally in time, and the average of the pressures for each time period may be selected as the target pressure. Converting the corresponding target pressure into an electric signal, wherein the preset width value is preferably 10 ms;

a2, S30, the controller 63 judges whether the target pressure of the current time period is increased or decreased compared with the target pressure of the previous time period; if the current time period is the first time period, the target pressure in the current time period is increased or decreased compared with the pressure of 0 value, and it is easy to think that the target pressure is not related to the pressure value in the loading base 15;

A3、

s311, if the pressure is increased, closing the negative pressure electromagnetic valve 611 and the negative pressure flow valve 612, and opening the positive pressure electromagnetic valve 620 and the positive pressure flow valve 619;

s312, if the pressure is reduced, closing the positive pressure electromagnetic valve 620 and the positive pressure flow valve 619, and opening the negative pressure electromagnetic valve 611 and the negative pressure flow valve 612;

a4, according to the judgment result of A3 or A7, adjusting the opening of the positive pressure flow valve 619 or the negative pressure flow valve 612 as required to adjust the pressure in the loading base 15;

a5, the controller 13 judges whether the end time is reached at present, that is, whether the loading process is finished, if yes, step A8 is executed, otherwise, step A6 is executed;

a6, the controller 63 executes the next time slot and judges whether the target pressure of the time slot of the step A5 needs to be changed, if yes, the step A2 is executed; if not, step a7 is executed, if the pressure does not change, the valve is controlled according to the actual and expected pressure difference;

a7, the controller 63 receives the electric signal from the pressure sensor 62, compares it with the electric signal converted from the target pressure in the time period in step a6 to obtain the difference between the electric signal of the pressure sensor 62 and the electric signal of the target pressure in the time period in step a6, and if the absolute value of the difference is less than or equal to a predetermined error, then step a5 is executed;

if the difference is smaller than zero and the absolute value of the difference is larger than the preset error, the pressure is increased, the negative pressure electromagnetic valve 611 and the negative pressure flow valve 612 are closed, the positive pressure electromagnetic valve 620 and the positive pressure flow valve 619 are opened, and the step A4 is executed;

if the difference is greater than zero and the absolute value of the difference is greater than the predetermined error, the pressure is reduced, the positive pressure electromagnetic valve 620 and the positive pressure flow valve 619 are closed, the negative pressure electromagnetic valve 611 and the negative pressure flow valve 612 are opened, and step a4 is executed;

a8, unloading the pressure in the loading base 15, opening the device to observe the cells and stopping the pneumatic system.

The example is described as a linear waveform diagram, in which the time varies from the initial time 0 to the end time 20ms, the pressure is kept at 2KPa, the preset width value is 10ms, and the preset error epsilon is 0.1 KPa.

B1、

S10, starting a pneumatic system;

s20, inputting a waveform of required pressure, and sequentially dividing time into a first time period and a second time period in sequence, wherein the width of each time period is 10 ms; assigning a target pressure to each time segment to fit a design value of the pressure for the time segment, where the pressure for each time segment is 2 KPa; the controller 63 converts the target pressure corresponding to each time period into an electric signal;

b2, S30 and the controller 63 judge that the current time period is the first time period, and the target pressure of the current time period is increased compared with the 0-value pressure;

b3 and S311, if pressurization is needed, closing the negative pressure electromagnetic valve 611 and the negative pressure flow valve 612, and opening the positive pressure electromagnetic valve 620 and the positive pressure flow valve 619;

b4, adjusting the opening of the positive pressure flow valve 619 to adjust the pressure in the loading base 15;

b5, the controller 63 finishes executing the current time period, judges that the ending time is not reached at present, namely, the second time period is needed to be executed, and executes the step B6;

b6, the controller 63 executes a second time period, and judges whether the value of the target pressure in the second time period compared with the target pressure in the previous time period needs to be changed, if not, the positive pressure electromagnetic valve 620 and the positive pressure flow valve 619 do not change the opening size, and executes step B7;

b7, the controller 63 receives the electric signal from the pressure sensor 62, compares the electric signal with the target pressure in the second time period, and if the difference is greater than the predetermined error, executes step B8;

b8, judging whether pressure is required to be increased or reduced according to the difference controller, and adjusting the opening of the positive pressure flow valve 619 or the negative pressure flow valve 612 as required to adjust the pressure in the loading base 15 so that the difference is smaller than or equal to a preset error;

b9, the controller 63 determines whether the ending time is reached at present, the system has already executed the second time period to reach the ending time, and executes step B10;

b10, unloading the pressure in the loading base 15, opening the device to observe cells conveniently, and stopping the pneumatic system.

Gas entering the gas chamber from the positive pressure pump connection port 153 can exit from the negative pressure pump connection port 155; the positive pressure pump connecting port 153 is connected with a pipeline port of the positive pressure pump and used as an air inlet of the device, the negative pressure pump connecting port 155 is connected with a pipeline port of the negative pressure pump and used as an air outlet of the device, and the pressure sensor connecting port 154 is connected with a pressure sensor which is used for monitoring the pressure in the device in real time; the clamping tool mounting groove 156 in the loading base 15 is used for mounting a clamping tool. Compared with the prior art that the air in the air chamber is singly controlled by only the negative pressure pump, the pneumatic system can simulate the air pressure of various waveforms, such as static, positive rotation, E-heart type, P-heart type, triangle, rectangle and various custom waveforms, by controlling the relationship between the total output air pressure value of the positive pressure pump and the negative pressure pump and the time.

Referring to fig. 1 to 14, a planar force cell loading device according to an embodiment of the present invention is used to provide planar mechanical loading to cells to simulate a single stress condition in a body, and can implement a plurality of mechanical loading waveforms in two directions, and includes a mechanical structure portion, a pneumatic system, and a control system, where the mechanical structure portion is connected to the pneumatic system, and the control system controls the pneumatic system to provide a desired positive pressure and a desired negative pressure to the mechanical structure portion, so as to simulate air pressures of various waveforms. The mechanical structure part comprises a transparent cover 11 for isolating from the external environment, a culture plate 12 for cell culture, a sealing ring 13 for sealing the device, two kinds of loading plates 14 for assisting in forming the loading, and a loading base 15 for providing support and an air passage. The mechanical and pneumatic parts are referred to the above description and will not be described in detail. Control systems are prior art in the field of control and will not be described in detail here.

The working principle of the device can be clearly understood with reference to fig. 3-6. FIG. 3 is a schematic view showing the first loading plate before operation, in which the loading membrane 124 of the culture plate 12 is located at a close distance from the first loading platform 1411 of the first loading plate 141, and can be considered to be in contact with the first loading platform, but no stress is generated. Fig. 4 is a schematic view of the loading plate in operation, when the device cavity is under negative pressure, the loading membrane 124 is divided into a first portion in contact with the loading platform and a second portion not in contact with the loading platform. The first portion is stretched around, the second portion is sucked down by the gas, and the cells on the first portion are subjected to radial two-dimensional tension. The load membrane around the first load table 1411 of the first load plate 141 is forced downward and the load membrane on the first load projection 1411 is tensioned along the radius of the load boss as shown in the top view force diagram of the first load plate in operation in fig. 5. The second type of loading plate operates on a similar principle to the first type of loading plate, and the second type of loading plate operates under the force in a plan view as shown in fig. 6, unlike the first type of loading plate, the loading membrane on the loading table 1411 of the second type of loading plate 141 is subjected to tension in a direction perpendicular to the linear side of the loading table.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the invention. In this specification, the schematic representations of the terms used above are not necessarily intended to refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples. Furthermore, various embodiments or examples and features of different embodiments or examples described in this specification can be combined and combined by one skilled in the art without contradiction.

While embodiments of the present invention have been shown and described above, it should be understood that the above embodiments are exemplary and should not be taken as limiting the invention. Variations, modifications, substitutions and alterations of the above-described embodiments may be made by those of ordinary skill in the art without departing from the scope of the present invention.

The above embodiments of the present invention should not be construed as limiting the scope of the present invention. Any other corresponding changes and modifications made according to the technical idea of the present invention should be included in the protection scope of the claims of the present invention.