Cell detachment device and cell detachment method

Abstract

Provided are a cell detachment device and a cell detachment method which are capable of efficiently detaching cells from a culture vessel in a non-contact manner. This cell detachment device (10) detaches cells (1) from a cell adhesion surface of a culture vessel (2), and comprises: a plurality of vibrators (11) which irradiate the cells (1) with ultrasonic beams (13) via the culture vessel (2); element driving units (14) which apply voltages to piezoelectric elements (411) of the vibrators (11); a scanning mechanism (15) which moves the positions of the vibrators (11) relative to the culture vessel (2); and a control unit (16) which controls the presence or absence of the output of the ultrasonic beams (13), the beam output intensity, and the positions of the vibrators (11), wherein the vibrators (11) are arranged along an arbitrary arrangement axis direction, and the scanning mechanism (15) scans the vibrators (11) along a scanning axis direction different from the arrangement axis direction.

Description

Cell detachment device and cell detachment method

[0001] The present invention relates to a cell detachment device and a cell detachment method.

[0002] In the field of regenerative medicine, treatments using cultured cells have been put to practical use. Cells are grown in specific cell culture vessels (hereinafter sometimes simply referred to as "culture vessels"), including cell culture dishes and plates, multiwell plates, microtiter plates, flasks, multi-cell culture flasks, and multi-layer cell culture vessels. During culture, cells adhere to the bottom of the culture vessel and grow. The grown cells form aggregates such as cell sheets, which are used for treatment.

[0003] As a method for detaching cells adhered to a culture vessel from the vessel, for example, the technique described in Patent Document 1 is known.

[0004] Patent Document 1 describes a cell detachment device that detaches cultured cells from a culture vessel to which the cells are attached. This cell detachment device includes an ultrasonic probe, a movement mechanism, a voltage application unit, a cell state detection unit, and a detachment planning unit. In this device, the ultrasonic probe has multiple piezoelectric elements that generate ultrasonic waves in response to an applied voltage and convert them into an ultrasonic beam. The movement mechanism moves the ultrasonic probe, enabling the relative position of the ultrasonic probe and the culture vessel to be changed. The voltage application unit is connected to the multiple piezoelectric elements and applies voltage to the multiple piezoelectric elements with a delay time. The cell state detection unit detects the state of the cells in the culture vessel. The detachment planning unit determines the transmission conditions of the ultrasonic beam by referring to the cell state obtained by the cell state detection unit.

[0005] That is, Patent Document 1 describes a technique for detaching cells by moving an ultrasonic probe relative to a cell culture vessel.

[0006] Japanese Patent Application Laid-Open No. 2023-069062

[0007] However, the cell detachment device described in Patent Document 1 still has room for improvement. For example, when the surface area of ​​a culture vessel is increased to culture a large number of cells, the cell detachment device described in Patent Document 1 requires a long time to evenly detach the entire culture vessel, raising concerns that this is inefficient. Therefore, it is considered desirable to improve this.

[0008] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a cell detachment device and a cell detachment method that can efficiently detach cells from a culture vessel in a non-contact manner.

[0009] The cell detachment device of the present invention, which solves the above-mentioned problems, is a cell detachment device that detaches cells from a cell adhesion surface of a culture vessel, and includes a plurality of transducers that irradiate the cells with ultrasonic beams through the culture vessel, an element driving unit that applies voltage to piezoelectric elements of the transducers, a scanning mechanism that moves the position of the transducers relative to the culture vessel, and a control unit that controls whether or not the ultrasonic beams are output, the beam output intensity, and the position of the transducers, wherein the transducers are arranged along an arbitrary array axis direction, and the scanning mechanism scans the transducers along a scanning axis direction that is different from the array axis direction.

[0010] The present invention provides a cell detachment device and a cell detachment method that can efficiently detach cells from a culture vessel in a non-contact manner. Problems, configurations, and effects other than those described above will become apparent from the following description of the embodiments.

[0011] 1 is a schematic diagram of a cell detachment device 10 according to a first embodiment; FIG. 2 is a plan view of the cell detachment device 10 according to the first embodiment; FIG. 3 is a schematic cross-sectional view of a transducer 11; FIG. 4 is a schematic plan view of a transducer 11; FIG. 5 is a schematic diagram showing an example of a beam shape 310 of an ultrasonic beam 13; FIG. 6 is a schematic diagram showing another example of a beam shape 310 of an ultrasonic beam 13; FIG. 7 is an explanatory diagram showing the arrangement of the direction of a major axis 321 of a flat beam shape 310 and the scanning axis, showing a configuration in which a direction perpendicular to the major axis 321 is the scanning axis; FIG. 8 is an explanatory diagram showing the arrangement of the direction of a major axis 321 of a flat beam shape 310 and the scanning axis, showing a configuration in which the direction of the major axis 321 is the scanning axis; FIG. 9 is an explanatory diagram of a case in which an ultrasonic beam 13 is irradiated onto an inner region of a cell sheet adhered to a cell adhesive surface inside a culture vessel 2; and FIG. 10 is an explanatory diagram of a case in which an ultrasonic beam 13 is irradiated onto an edge of a cell sheet. FIG. 11 is a schematic diagram of a cell detachment device 10, explaining the control unit 16 in detail. 1 is an explanatory diagram illustrating an example of a voltage waveform output from an element driving unit 14 and applied to each transducer 11 constituting an ultrasonic probe 12. FIG. 2 is a schematic diagram illustrating cells 1 on a cell culture surface in a culture vessel 2 with a detachment region 511 and a non-detachment region 512. FIG. 3 is a schematic diagram illustrating an example of time-series control of the transducer 11 in the first embodiment. FIG. 4 is a schematic diagram illustrating an example of an array axis and a scanning axis of the transducer 11. FIG. 5 is a schematic diagram illustrating another example of the array axis and the scanning axis of the transducer 11. FIG. 6 is a schematic diagram illustrating another example of the array axis and the scanning axis of the transducer 11. FIG. 7 is a schematic diagram illustrating another example of the array axis and the scanning axis of the transducer 11. FIG. 8 is a schematic diagram illustrating a cell detachment device 10 according to a first modified example of the first embodiment. FIG. 9 is a schematic diagram illustrating a configuration example of the cell detachment device 10 according to the first modified example of the first embodiment, particularly illustrating in detail a configuration example of the control unit 16. FIG. 10 is a schematic diagram illustrating an example of time-series control of the transducer 11 in the first modified example of the first embodiment. FIG. 11 is a schematic diagram illustrating a cell detachment device 10 according to a second modified example of the first embodiment. FIG. 1 is a schematic diagram of a cell detachment device 10 according to a second embodiment. FIG. 2 is a schematic diagram showing an example of a database 52 having ultrasonic irradiation conditions. FIG. 3 is a flowchart illustrating one aspect of a cell detachment method according to the present embodiment. FIG. 4 is a flowchart illustrating another aspect of a cell detachment method according to the present embodiment. FIG. 5 is a flowchart illustrating the contents of a specific example of a cell detachment method according to the present embodiment.

[0012] Hereinafter, a cell detachment device and a cell detachment method according to one embodiment of the present invention will be described in detail with reference to the accompanying drawings. In the description of each embodiment, substantially the same or similar components are designated by the same reference numerals, and redundant descriptions may be omitted.

[0013] The cell detachment device and method according to this embodiment detach cells that are adhered to a cell adhesion surface, which is the culture surface of a culture vessel. In this specification, the cell adhesion surface refers to the surface in the culture vessel to which cells adhere. The cell adhesion surface may be flat or curved. The cell detachment device according to this embodiment can be used as part of a cell culture device. Furthermore, the cell detachment method according to this embodiment describes, as an example, a method of culturing adherent cells by forming a cell culture medium in a commonly used cell culture dish, but the scope of application is not limited to this. Furthermore, this embodiment can target various culturable adherent cells and is not limited to specific cells. Furthermore, the medium used for cell culture in this embodiment can be either a serum-free medium or a serum-added medium.

[0014] Furthermore, the culture vessel is not limited to a single-layer or double-layered vessel. A single-layer culture vessel is one in which the inner wall of the culture vessel serves as the cell adhesion surface. A double-layer culture vessel is one in which, for example, a sheet-like member is provided inside the culture vessel, and the surface of the sheet-like member as well as the inner wall of the culture vessel serve as the cell adhesion surface. The cell detachment device and method according to this embodiment are intended for culture vessels with a cell adhesion surface inside the culture vessel, and may also be a culture vessel with multiple sheets. Note that, in this specification, the term "culture vessel" refers to any container in which cells are stored and is not limited to those used for cell culture. For example, the cell detachment device and method according to this embodiment can be applied to detaching cells after culturing them in a culture vessel. The cell detachment device and method according to this embodiment can also be applied to transporting cells using a container (culture vessel) and then removing the cells as needed.

[0015] In order to explain this embodiment, a system will be described in which an ultrasonic beam is irradiated upward from the outside of the bottom surface of a culture vessel in a state of single-layer culture in which cells immersed in a culture medium in a culture vessel adhere to the bottom surface. However, this embodiment is not limited to this system and can be applied to a system in which ultrasonic waves are transmitted from the side or top surface of the culture vessel through the culture medium, etc.

[0016] In the cell detachment device and method according to this embodiment, an ultrasonic probe equipped with multiple transducers is placed on the outside of the culture vessel, for example, on the outside of the bottom surface, and ultrasonic beams with arbitrarily controlled beam output are irradiated from this ultrasonic probe onto cells adhered to the culture surface of the culture vessel. The ultrasonic probe and the outer surface of the culture vessel may be in contact via an acoustic coupler for efficient transmission of ultrasonic waves, or a matching layer made of silicone rubber, fluororubber, or the like. Alternatively, the ultrasonic probe (transducers) and the outer surface of the culture vessel may not be in direct contact with each other, but may be placed with a fluid interposed between them.

[0017] In the cell detachment device and method according to this embodiment, an ultrasonic probe emits an ultrasonic beam having a certain intensity or higher, thereby applying acoustic radiation pressure to cells. Furthermore, acoustic streaming may occur along the path of the ultrasonic beam. An upward force is applied to the cells by the acoustic radiation pressure and / or acoustic streaming. Experiments have confirmed that cells can be detached from the cell adhesion surface of a culture vessel by emitting an ultrasonic beam with an ultrasonic intensity exceeding a certain threshold (detachment threshold). Ultrasonic forces include forces due to high-speed mechanical vibrations and forces due to sound waves. In this specification, to distinguish between the two, high-speed mechanical vibrations will be referred to as "vibration force" and forces due to sound waves will be referred to as "acoustic force." Acoustic force includes the driving forces of the acoustic radiation pressure and acoustic streaming described above. The cell detachment device and method according to this embodiment use acoustic force to detach cells.

[0018] In this embodiment, the beam output of the arbitrarily controlled ultrasonic beam may be, for example, an ultrasonic beam whose intensity, transmission time (duty ratio, repetition interval), etc. are electronically controlled. Note that the ultrasonic beam refers to a band-like or rod-like region formed by ultrasonic waves transmitted from a piezoelectric element.

[0019] The intensity of the beam output of the ultrasonic beam can be controlled, for example, by the following methods: Changing the intensity of the voltage applied to the transducer of the ultrasonic probe; Changing the wave number (number of sine waves) of the voltage waveform to be applied; In the case of an ultrasonic probe having multiple piezoelectric elements, selecting all or some of the piezoelectric elements to which voltage is applied. Note that the voltage waveform is not limited to a sine wave and may be, for example, a rectangular wave.

[0020] The transmission time of the ultrasonic beam can be controlled, for example, by the following methods: Changing the wave number or application time of the voltage applied to the piezoelectric element of the ultrasonic probe at a specific frequency. The specific frequency is determined by the dimensions and material of the piezoelectric element and is arbitrarily determined depending on the piezoelectric element. According to experiments conducted by the inventors of the present application, the preferred frequency for cell detachment is approximately 150 kHz to 50 MHz. While the methods for controlling the intensity and transmission time of the ultrasonic beam have been described above, these control methods are not limited to those described above.

[0021] In this embodiment, the ultrasonic probe includes multiple transducers, which are arranged in an arbitrary axial direction. In this specification, this axis is referred to as the array axis. The multiple transducers scan along a scanning axis that is different from the array axis and is generally perpendicular to the array axis. In this case, multiple transducers that generate ultrasonic beams may scan simultaneously, or individual transducers may be selected in order to scan.

[0022] The cell detachment device according to this embodiment adjusts the beam intensity of the ultrasonic beam output to a level exceeding a specific threshold (detachment threshold) based on the coordinate data and the desired detachment area within the culture vessel, and locally irradiates the ultrasonic beam from outside the culture vessel through the bottom surface to sever the bond between the cells and the cell adhesion surface. The desired detachment area can be the entire culture vessel or a specific part of it.

[0023] For example, by scanning a transducer corresponding to the coordinates of the array axis of the desired ablation region on a track that passes through the desired ablation region and irradiating the cells with an ultrasonic beam, it is possible to efficiently ablate only a desired region. In this embodiment, multiple transducers corresponding to the desired region can be scanned simultaneously or sequentially, allowing for efficient ablation even in a large ablation region.

[0024] Therefore, the cell detachment device according to this embodiment can detach cells from a culture vessel in a non-contact manner, and as a result, a cell culture device equipped with the cell detachment device according to this embodiment can automate the cell detachment process and achieve high throughput.

[0025] First Embodiment Next, a specific embodiment (first embodiment) of the cell detachment device according to the present invention will be described. FIG. 1A is a schematic diagram of a cell detachment device 10 according to the first embodiment. FIG. 1B is a plan view of the cell detachment device 10 according to the first embodiment. Note that in this specification and the drawings, the directions of the x, y, and z axes are indicated in the drawings to show the relative positions of the drawings. In the coordinate axis display, a double circle indicates an arrow pointing from the back side of the drawing to the front side, and an x ​​indicates an arrow pointing from the front side of the drawing to the back side. Note that the coordinate system display of the x, y, and z axes indicates the direction of the axes, and the origin position is irrelevant. Furthermore, since the coordinate system display indicates the relative orientation of the drawings, it goes without saying that the direction of the x axis is arbitrary. In this specification, the x axis is aligned with the scanning direction (scanning axis), and the x-y plane is aligned parallel to the scanning plane. The z axis is aligned perpendicular to the x-y plane.

[0026] In this embodiment, for example, the following configuration is disclosed. As shown in FIG. 1A , a cell detachment device 10 according to this embodiment is a device that detaches cells 1 during culture by transmitting ultrasound to the cells 1 that are adhered to the cell adhesion surface of a culture vessel 2. The cell detachment device 10 has an ultrasonic probe 12, an element drive unit (drive circuit) 14, a scanning mechanism 15, and a control unit 16. The ultrasonic probe 12 is connected to the element drive unit 14. The element drive unit 14 and the scanning mechanism 15 are connected to the control unit 16. The cell detachment device 10 also has an input unit 56 and a display unit 57 (both of which are shown in FIG. 6 ).

[0027] The ultrasonic probe 12 has a plurality of transducers 11, and generates ultrasonic beams 13 in response to an applied voltage. The ultrasonic beams 13 generated by the plurality of transducers 11 are irradiated onto the cells 1 through the culture vessel 2. The element driver 14 is connected to the transducers 11 and applies a voltage to the piezoelectric elements 411 (see FIGS. 2A and 2B ) of the transducers 11. The scanning mechanism 15 moves the ultrasonic probe 12 as shown by the arrow (scanning axis) in FIG. 1B to move the position of the ultrasonic probe 12 relative to the culture vessel 2, i.e., the position of the transducers 11. With this configuration, the ultrasonic probe 12 is moved, allowing the cells 1 to be efficiently detached.

[0028] The control unit 16 controls whether or not to output the ultrasonic beam 13, the beam output intensity, and the position of the transducer 11. The control unit 16 may also include an input unit 56 (see FIGS. 6, 12, and 15). The input unit 56 inputs the shape of the region of cells 1 to be detached from the cell adhesion surface of the culture vessel 2. The control unit 16 controls the element driving unit 14 and the scanning mechanism 15 using information obtained from the input unit 56. The control unit 16 controls whether or not to apply a voltage to the transducer 11, the intensity of the applied voltage, the wave number, and the repetition time. Furthermore, the control unit 16 controls the scanning mechanism 15 based on the coordinates of the desired detachment region 511 (see FIG. 8).

[0029] The cell detachment device 10 has transducers 11 arranged along an arbitrary array axis direction, and a scanning mechanism 15 causes the transducers 11 to scan along a scanning axis direction different from the array axis direction. In this manner, the cell detachment device 10 can scan the arranged transducers 11 in a scanning axis direction different from the array axis direction (e.g., a direction perpendicular to the array axis direction). This allows the cell detachment device 10 to efficiently detach cells 1 from the cell adhesion surface of the culture vessel 2. The cell detachment device 10 also irradiates the cells 1 with an ultrasonic beam 13 through the culture vessel 2. This allows the cell detachment device 10 to detach cells 1 from the cell adhesion surface of the culture vessel 2 in a non-contact manner. Furthermore, the cell detachment device 10 has transducers 11 arranged along an arbitrary array axis direction. Therefore, the cell detachment device 10 can reduce the size of the ultrasonic probe 12 (the number of transducers 11 can be reduced) compared to, for example, a case in which the transducers 11 are provided to cover the entire bottom surface of the culture vessel 2, thereby reducing costs.

[0030] (Culture vessel and cell adhesion surface) The culture vessel 2 has cells 1 inside it. In this specification, the surface inside the culture vessel 2 to which the cells 1 are attached is called the cell adhesion surface. The cell adhesion surface may be the inner wall of the culture vessel 2. Alternatively, another member may be placed inside the culture vessel 2 and the cells 1 may be cultured on the surface of that member, in which case the surface of the member to which the cells 1 are attached becomes the cell adhesion surface.

[0031] The cell detachment device 10 is configured to irradiate cells 1 attached to a cell adhesion surface inside a culture vessel 2 and immersed in a culture solution 3 such as a medium with an ultrasonic beam 13 to detach the cells 1 from the cell adhesion surface. The cells 1 are adhered to the inner bottom surface of the culture vessel 2 in the form of, for example, cells, colonies, cell sheets, organoids, etc. That is, in this embodiment, the inner bottom surface of the culture vessel 2 is the cell adhesion surface.

[0032] 1A, the ultrasonic beam 13 is indicated by two dotted lines. The entire area between the two dotted lines is the ultrasonic beam 13. The ultrasonic beam 13 is emitted from the transducer 11 and irradiated onto the cells 1 in the culture vessel 2 via the fluid 4 and the vessel wall of the culture vessel 2. Since the present invention uses the acoustic force of ultrasound to detach the cells 1, the energy of the ultrasonic beam 13 can be transmitted between the transducer 11 and the culture vessel 2 even via the fluid 4.

[0033] In FIG. 1A, cells 1 are depicted as a group of many cells 1. To give a specific example, the width of the transducer 11 in the long axis direction (y-axis in FIG. 1A) is typically 5 to 40 mm. On the other hand, the size of each cell 1 is typically 10 to 50 micrometers. Therefore, many cells 1 are located within the range of the long axis width of the transducer 11. For convenience, in FIG. 1A, the many cells 1 are collectively shown as a single oval. This is also true in other drawings in this specification.

[0034] The culture vessel 2 is partially immersed in a fluid 4, which is a contact medium, in a tank 5 as shown in Figures 1A and 1B. Specifically, as shown in Figures 1A and 1B, a highly viscous fluid 4 that can efficiently transmit ultrasound can be supplied between the ultrasonic probe 12 and the culture vessel 2. In this embodiment, water can be used as such a fluid 4. However, the configuration between the culture vessel 2 and the cell detachment device 10 is not limited to this.

[0035] 1A, an ultrasonic probe 12 is placed outside the culture vessel 2 and is preferably immersed in the fluid 4. A transducer 11 in the ultrasonic probe 12 irradiates an ultrasonic beam 13 onto cells 1 in the culture vessel 2 through the fluid 4 and the cell adhesion surface.

[0036] (Configuration of Ultrasonic Probe) An example configuration of the transducer 11 (ultrasonic transducer) will be described using FIGS. 2A and 2B . FIG. 2A is a schematic cross-sectional view of the transducer 11. FIG. 2B is a schematic plan view of the transducer 11. As shown in FIGS. 2A and 2B , the transducer 11 includes, as an example, a flat piezoelectric element 411. The transducer 11 includes a ground electrode 412 on the upper surface of the piezoelectric element 411, i.e., on the side facing the culture vessel 2, and a protective film 415 adhered to the upper surface of the ground electrode 412. The protective film 415 of the transducer 11 comes into contact with the fluid 4. The protective film 415 is a thin film made of metal or resin. The transducer 11 also includes a signal electrode 413 that applies a voltage to the lower surface of the piezoelectric element 411. The shape of the piezoelectric element 411 can be, but is not limited to, a circle, an ellipse, a rectangle (square in plan view in FIGS. 2A and 2B ), or the like. The connection portion between the signal electrode 413 and the signal line 17 (FIG. 1A) is covered with resin and fixed.

[0037] The piezoelectric element 411 is an element that converts an electrical signal into mechanical motion. In this embodiment, the piezoelectric element 411 emits an ultrasonic beam 13 into the fluid 4 by applying a high-frequency electrical signal. The piezoelectric element 411 is made of, for example, ceramics such as lead zirconate titanate or lead titanate, materials such as zinc oxide or lithium niobate, or a composite (composite material). The ground electrode 412 and the signal electrode 413 are made of, for example, gold, silver, copper, platinum, titanium, aluminum, or other materials. The piezoelectric element 411 may also be a composite piezoelectric material in which multiple piezoelectric materials are solidified with resin or the like.

[0038] 2B, the signal electrode 413 is shown by a dotted line because it is located on the back surface of the piezoelectric element 411. When a voltage is applied to the signal electrode 413, an electric field is applied to the piezoelectric element 411 in the region where the signal electrode 413 and the ground electrode 412 overlap, and an ultrasonic beam 13 is emitted from the overlapping region of the two electrodes. In this way, by appropriately designing the overlapping shape of the signal electrode 413 and the ground electrode 412, a desired beam shape 310 (FIGS. 3A and 3B), such as a rectangle or an ellipse, can be obtained.

[0039] In this embodiment, the upper surface side is the ground electrode 412, but the upper surface side may be the signal electrode 413 and the lower surface side may be the ground electrode 412. Also, a voltage may be applied to both the ground electrode 412 and the signal electrode 413. In either case, it goes without saying that an appropriate electric field can be applied to the piezoelectric element 411, and therefore the ultrasonic beam 13 can be generated.

[0040] A single piezoelectric element 411 may be configured with a plurality of transducers 11. As described above, the ultrasonic beam 13 is emitted from the overlapping region between the signal electrode 413 and the ground electrode 412. Therefore, by providing a plurality of signal electrodes 413, a plurality of overlapping regions between the signal electrode 413 and the ground electrode 412 can be created. Each overlapping region becomes a transducer 11. Even in this case, the transducer 11 that emits the ultrasonic beam 13 can be selected by selecting the signal electrode 413 to which a voltage is applied, thereby achieving the effect of this embodiment.

[0041] (Cell Surface and Beam Shape) Before explaining the beam shape 310, the cell surface is defined. The cell surface is defined as the surface in the culture vessel 2 to which the cell 1 to be detached is attached. Usually, the cell surface coincides with the cell adhesion surface. In this specification, the z-direction position of the cell surface is referred to as the cell surface height zc.

[0042] Next, the beam shape 310 of the ultrasonic beam 13 emitted from the ultrasonic probe 12 will be described with reference to Figures 3A and 3B. Figure 3A is a schematic diagram showing an example of the beam shape 310 of the ultrasonic beam 13. Figure 3B is a schematic diagram showing another example of the beam shape 310 of the ultrasonic beam 13. In this specification, the beam shape 310 is defined as the shape of the ultrasonic beam 13 on the cell surface.

[0043] As shown in Figures 3A and 3B, the beam shape 310 of the ultrasonic beam 13 emitted from the ultrasonic probe 12 has a flat shape. In this specification, a flat shape refers to a shape whose widths vary in directions perpendicular to each other, and includes, for example, a rectangle (specifically, a rectangle in Figure 14A) or an ellipse (Figure 14B). In this specification, the longitudinal direction of the flat beam shape 310 is referred to as the major axis 321, and the direction of the short side is referred to as the minor axis 322. The minor axis 322 is set in a direction perpendicular to the major axis 321.

[0044] In this embodiment, the direction of the minor axis 322 is usually set as the scanning axis direction (see FIG. 1B ). The array axis along which the ultrasonic probes 12 are arranged is usually set as the direction of the major axis 321. When the ultrasonic probe 12 is installed in this direction, the beam irradiation area increases when the ultrasonic beam 13 is scanned a certain distance Δx, so that the cell 1 can be efficiently ablated.

[0045] Typically, the long axis 321 is arranged perpendicular to the scanning axis, but it is sufficient if it is approximately perpendicular. In Fig. 3A, consider a case where the scanning axis of the ultrasonic beam 13 is the x-axis direction, and the long axis 321 of the beam shape 310 is offset by an angle θ from the perpendicular direction (i.e., the y-axis). When the width of the long axis 321 of the beam shape 310 is WL and the beam shape 310 is scanned a distance Δx, the sweep area ΔS is given by Equation 1. ΔS = WL × Δx × cos θ (Equation 1)

[0046] ΔS given by Equation 1 is maximized when θ = 0, which is preferable because it allows efficient detachment of cell 1. However, even if θ is slightly shifted, for example, when θ = 40°, ΔS remains at 77% of the maximum value, and the effect of this embodiment can be obtained. In other words, an angle shifted by ±40° from the y-axis can also be considered "approximately right angles."

[0047] As a configuration for realizing the flat beam shape 310, for example, the overlapping region of the electrode shapes sandwiching the piezoelectric element 411 may be made flat. Alternatively, the beam shape 310 may be made flat by selecting specific vibrators 11 from a plurality of array-shaped vibrators 11. The configuration for making the beam shape 310 flat is not limited to this.

[0048] Alternatively, the transducer 11 may be curved so that its cross section is U-shaped, and may emit a linearly convergent ultrasonic beam 13. The use of such a linearly convergent ultrasonic probe has the effect of widening the beam emission area, thereby obtaining a strong ultrasonic beam 13 near the convergence position. Even when a linearly convergent ultrasonic probe is used, the beam shape 310 on the cell surface is flat. In this case, the beam shape 310 on the cell surface also defines the long axis 321 and short axis 322 directions.

[0049] (Relationship between the Long Axis of the Flat Shape and the Scanning Axis) In this embodiment, it is important that the beam shape 310 of the ultrasound emitted by the transducer 11 is flat and that the direction generally perpendicular to the long axis 321 of the beam shape 310 is the scanning axis. The effects of this configuration will be described. FIG. 4A is an explanatory diagram showing the arrangement of the direction of the long axis 321 of the flat beam shape 310 and the scanning axis, and is a diagram showing a configuration in which the direction perpendicular to the long axis 321 is the scanning axis. FIG. 4B is an explanatory diagram showing the arrangement of the direction of the long axis 321 of the flat beam shape 310 and the scanning axis, and is a diagram showing a configuration in which the direction of the long axis 321 is the scanning axis. The width of the long axis 321 is designated WL, and the width of the short axis 322 is designated WS. Hereinafter, the configuration of FIG. 4A will be referred to as Configuration A, and the configuration of FIG. 4B will be referred to as Configuration B.

[0050] As an example, in configuration A of FIG. 4A, WL = 20 mm and WS = 3 mm. In configuration B of FIG. 4B, WL = 10 mm and WS = 6 mm. Since the beam area of ​​beam shape 310 is WL x WS, the beam area is equal in configurations A and B. Therefore, if the ease of detachment from the cell adhesion surface is constant regardless of location, the amount of detachment that can be achieved with one irradiation of ultrasonic beam 13 should be the same in both cases. However, when detaching cell 1, using configuration A can achieve the effects described below.

[0051] The inventors have experimentally found that when cells 1 are detached by irradiation with an ultrasonic beam 13, the adhesiveness between the cells 1 and the cell adhesive surface varies depending on the location. For example, taking a cell sheet as an example of the cells 1, the cells 1 are easily detached by the ultrasonic beam 13 at the edges of the cell sheet, but are difficult to detach from the inner region of the cell sheet.

[0052] Furthermore, the inventors discovered that the impact on cells 1 is smaller when the cell sheet is peeled from the edge. The reason for this will be explained using Figures 5A and 5B. Figure 5A is an explanatory diagram of the case where an ultrasonic beam 13 is irradiated onto the inner region of a cell sheet adhered to the cell adhesive surface inside a culture vessel 2. Figure 5A shows an enlarged view of the area irradiated with the ultrasonic beam 13, with the culture medium 3 not shown. As shown in Figure 5A, when the ultrasonic beam 13 is irradiated, cells 1-1 in the irradiated area are detached. However, because cells 1-1 in the irradiated area are in the inner region of the cell sheet, cells 1 around the detached area (cells 1-2 at the detachment boundary) remain attached to the cell adhesive surface. Therefore, strain stress is applied to cells 1-2 at the detachment boundary, which deforms cells 1 and negatively affects cells 1-2 at the detachment boundary. In other words, mechanical stress is applied to cells 1-2 at the detachment boundary, which negatively affects cells 1-2 at the detachment boundary. Furthermore, the cell sheet may be damaged by stress that mechanically stretches cells 1-1 in the irradiated area.

[0053] In contrast, Figure 5B is an explanatory diagram of the case where an ultrasonic beam 13 is irradiated onto the edge of a cell sheet. In this case, cells 1-1 at the irradiated portion of the detached edge are not fixed to the cell adhesion surface, so the strain stress on cells 1-2 at the detachment boundary is significantly reduced. According to experiments by the inventors, the edge is considered to be within 5 mm from the edge of the cell sheet, but it is more preferable if it is within 3 mm from the edge.

[0054] Returning to FIG. 4 , we continue the explanation. In the configuration A of FIG. 4A , WS = 3 mm, so that a single irradiation of the ultrasonic beam 13 irradiates only the edge of the cell sheet. This makes the cells 1 easily peel off, and the strain stress on the cells 1 becomes negligibly small. When the edge of the cell sheet peels off, the position of the peeling boundary becomes a new edge. Therefore, if the beam irradiation position is moved in the scanning axis direction by a width WS = 3 mm of the minor axis 322 and the next ultrasonic beam 13 is irradiated, the ultrasonic beam 13 is sequentially irradiated to a new edge region, making it possible to easily peel off the cells 1. In this way, by using a flat beam shape 310 and scanning in a direction approximately perpendicular to the major axis 321 of the beam shape 310, the cell sheet can be peeled off sequentially from the edge, and the cells 1 can be easily peeled off.

[0055] On the other hand, in configuration B of FIG. 4B , a single irradiation of the ultrasonic beam 13 irradiates a range of WL = 10 mm from the edge of the cell sheet. Therefore, the ultrasonic beam 13 is also irradiated to the inner region of the cell sheet. This makes it difficult for the cells 1 to peel off, and increases the strain stress on the cells 1 in the inner region. For the above reasons, in this embodiment, the width WS of the minor axis 322 of the beam shape 310 of the flat ultrasonic beam 13 is preferably 5 mm or less. In this embodiment, it is more preferable to set the width WS of the minor axis 322 to 3 mm or less. Furthermore, in this embodiment, it is even more preferable to set the width WS of the minor axis 322 to 2 mm.

[0056] While the above description uses a cell sheet as an example, the same applies to cells 1 that are not sheet-shaped. The configuration of this embodiment shown in FIG. 4A is also effective in terms of high-speed detachment and device cost. The drive current required for the element driver 14 that drives the transducer 11 is proportional to the area of ​​the transducer 11. Since an increase in drive current increases the cost of the circuitry constituting the element driver 14, the area of ​​the transducer 11 affects cost. Meanwhile, since reducing the number of scans in the y-axis direction is effective for high-speed detachment, it is preferable to increase the width of the transducer 11 in the y-axis direction (width WL of the major axis 321). More preferably, the length of the ultrasonic probe 12 in the y-axis direction is longer than the length of the culture vessel 2 in the y-axis direction. In this way, cells 1 can be detached from the entire culture vessel 2 by scanning only in the x-axis direction, so a single-axis scanning device is sufficient, which not only increases speed but also reduces device costs.

[0057] 4A (Configuration A) and 4B (Configuration B), when the area of ​​the transducer 11 is constant, the length of the ultrasonic probe 12 in the y-axis direction can be made longer in Configuration A. This provides the advantage of achieving both high-speed detachment and low device costs. As described above, in the cell detachment device 10, the beam shape 310 of the ultrasonic beam 13 emitted by the transducer 11 is flattened, and the scanning axis is positioned approximately perpendicular to the major axis 321 of the beam shape 310, thereby providing the advantage of making it easier to detach the cells 1.

[0058] (Element driving unit and scanning mechanism) Returning to Fig. 1 , the explanation will continue. The element driving unit 14 applies a voltage to the transducers 11 of the ultrasonic probe 12 based on a control command from the control unit 16, causing the transducers 11 to generate an ultrasonic beam 13 having a desired beam output. An element driving unit 14 is provided for each transducer 11, and applies a voltage to the transducer 11 independently. The voltage waveform applied to the transducer 11 will be described later. The order in which the four transducers 11 shown in Figs. 1A and 1B are driven (drive sequence) will also be described later.

[0059] The scanning mechanism 15 is a mechanism for moving the ultrasonic probe 12 and the culture vessel 2 relatively. In this embodiment, the scanning mechanism 15 is configured to move the ultrasonic probe 12 along the outer surface of the bottom of the culture vessel 2 and along a trajectory calculated by the control unit 16. The scanning mechanism 15 may be configured using a well-known mechanism such as an X-Y axis moving table. Note that the scanning mechanism 15 may be attached to the culture vessel 2, and the positions of the ultrasonic probe 12 and the culture vessel 2 may be moved relatively by scanning the culture vessel 2.

[0060] (Control Unit and Scanning Path Calculation Unit) The configuration of the control unit 16 will be described with reference to FIG. 6. FIG. 6 is a schematic diagram of the cell detachment device 10, illustrating the control unit 16 in detail. As shown in FIG. 6, the control unit 16 has a beam control unit 53, a beam condition determination unit 54, a scanning path calculation unit 55, and a planning unit 59 as internal functions realized by executing software on hardware. In the example shown in FIG. 6, the beam control unit 53 is connected to each element driving unit 14 and controls the driving of each element driving unit 14. The scanning path calculation unit 55 is connected to the scanning mechanism 15 and controls scanning by the scanning mechanism 15.

[0061] In other words, the beam control unit 53 and the scanning path calculation unit 55 calculate the path for moving the ultrasonic probe 12 to ablate the desired area of ​​the cell 1 and the output of the ultrasonic beam 13 at a position on the path, and control the scanning mechanism 15 and the ultrasonic probe 12.

[0062] For example, the planning unit 59 refers to the irradiation conditions of the ultrasonic beam 13 input by the input unit 56 and the coordinates of the desired ablation region 511, and plans the intensity of the ultrasonic beam 13 and the coordinates to be scanned. Based on this, the scanning path calculation unit 55 issues a scanning instruction to the scanning mechanism 15.

[0063] The beam condition determination unit 54 determines the voltage and waveform to be applied to the transducers 11 by the element driving unit 14 based on the irradiation conditions of the ultrasonic beam 13 planned by the planning unit 59. The transducers 11 that irradiate ultrasonic waves may be switched on software using a circuit based on an electrical signal. Alternatively, the transducers 11 that irradiate ultrasonic waves may be switched using a physical button or the like.

[0064] The beam control unit 53 controls the conditions of the voltage to be applied to the element driving unit 14 based on the applied voltage and waveform determined by the beam condition determination unit 54. The beam control unit 53 calculates the signal and intensity of the voltage to be applied to the ultrasonic probe 12.

[0065] The scan path calculation unit 55 calculates the path of the ultrasonic probe 12 moved by the scanning mechanism 15 based on the irradiation position planned by the planning unit 59. The trajectory of the ultrasonic beam 13 by the scan path calculation unit 55 can be arbitrarily set by the input unit 56. The scan path calculation unit 55 calculates the coordinates of the ultrasonic probe 12 based on the input shape so that the ultrasonic beam 13 is irradiated starting from an arbitrary coordinate point of an arbitrary ultrasonic probe 12 and following the input shape. After the ultrasonic beam 13 is irradiated to the planned irradiation position, the scan path calculation unit 55 calculates the amount of movement of the ultrasonic probe 12 to the next specified position.

[0066] The input unit 56 inputs information specifying the region to be detached from the cells 1 on the cell adhesion surface of the culture vessel 2. For example, the input unit 56 can input information for cutting out a detached portion having a desired shape from the cells 1 being cultured, which is displayed on the display unit 57. The input unit 56 has a keyboard and a mouse, and an operator or the like inputs information, and the input information such as the shape of the detached portion is provided to the database 52 and the control unit 16.

[0067] The display unit 57 is provided to assist the input unit 56 and allows input while referring to input information. The display unit 57 may be provided as needed. The database 52 stores the irradiation conditions of the ultrasonic beam 13, i.e., control data of the ultrasound required for detaching the cells 1, such as the size, intensity, and transmission time of the ultrasonic beam 13, depending on the type of ultrasonic probe 12 (or transducer 11) used, the type of cultured cells, the type of culture vessel 2, the number of days of culture, and the state of culture. The database 52 is not essential, but providing the database 52 allows the control unit 16 (e.g., the beam condition determination unit 54) to appropriately set the irradiation conditions of the ultrasonic beam 13 depending on the type and state of the cells 1, the type of culture vessel 2, and the like, thereby enabling more efficient detachment of the cells 1.

[0068] (Vibrator Drive Waveform) FIG. 7 is an explanatory diagram illustrating an example of a voltage waveform output from the element driver 14 and applied to each vibrator 11 constituting the ultrasonic probe 12. The voltage waveform applied by the element driver 14 is a burst waveform, and is composed of a wave packet made up of N fundamental waves. One wave packet is a waveform in which a waveform (fundamental wave) of fundamental frequency f0 is repeated N cycles. In this specification, the period between a wave packet and the next wave packet is called a repetition period Tr. In this embodiment, the repetition period Tr is typically 0.2 seconds to 2 seconds. In this embodiment, it is preferable to set the repetition period Tr to 1 second. The wave packet repetition period Tr is not limited to these values.

[0069] In this embodiment, as shown in Figure 7, a sine wave can be used as the fundamental wave, but a square wave or a triangular wave can also be used. Using a square wave has the advantage of simplifying the circuit configuration of the element driving unit 14. In this embodiment, the fundamental frequency f0 is set to 1 MHz, and the number of cycles N of the fundamental wave can be set to 3000. In other words, N cycles of the fundamental wave constitute one wave packet. It goes without saying that the setting ranges of the fundamental frequency f0 and the number of cycles N are not limited to these.

[0070] The fundamental frequency f0 can be set in the range of 150 kHz to 50 MHz. It is known that if the fundamental frequency f0 is set to less than 150 kHz, cavitation is more likely to occur in the culture solution 3, although this depends on the type of culture solution 3. Since the shock waves emitted by the cavitation may affect the cells 1, it is desirable to set the frequency to 150 kHz or more, and more desirable to set the frequency to 200 kHz or more, so as not to affect the cells 1. Furthermore, if the frequency exceeds 50 MHz, it becomes difficult to design the element driving unit 14. It is more preferable that the range of the fundamental frequency f0 is 400 kHz to 5 MHz. In addition, one period T ０ is the fundamental frequency f0 / (i.e., T ０ = 1 / f0).

[0071] The wavelength of ultrasound is expressed by Equation 2, where c is the speed of sound (m / s) and f is the frequency (Hz): λ = c / f (Equation 2) Since the speed of sound in the culture solution 3 is approximately 1500 (m / s), if f0 = 1 MHz, the wavelength λ is 1.5 mm. In this embodiment, as described above, the acoustic force of the ultrasound beam 13 is used, and if the ultrasound beam 13 spreads, the acoustic force per unit area at the cell adhesion surface decreases. To keep the spread of the ultrasound beam 13 to a few mm, it is preferable to set the ultrasound wavelength to 4 mm or less. To achieve this, it is preferable that the fundamental frequency f0 be 400 kHz or higher.

[0072] (Drive Sequence of Transducers) Next, the drive sequence of the multiple transducers 11 in the cell detachment device 10 shown in FIG. 1 will be described. FIG. 8 is a schematic diagram showing cells 1 on the cell culture surface in a culture vessel 2 as a detachment region 511 and a non-detachment region 512. In the figure, the shaded region is the non-detachment region 512, and the remaining region is the detachment region 511. The numbers 1 to 4 arranged vertically correspond to the numbers of the four transducers 11. The letters t1, t2, etc. arranged horizontally indicate the x-axis positions at which cells 1 are detached at times t1 and t2, respectively. As shown in FIG. 8, in this embodiment, the element driver 14 is turned on / off and output controlled for each of the four transducers 11, starting from the left end of the culture vessel 2 and corresponding to times t1, t2, etc. This allows control to be performed so that cells 1 are detached in the detachment region 511 and not detached in the non-detachment region 512.

[0073] Fig. 9 is a schematic diagram showing an example of time-series control of the transducer 11 in the first embodiment. Fig. 9 shows the drive sequence of the transducer 11 for detaching the cell 1 in the detachment region 511 in Fig. 8. The numbers 1 to 4 in the vertical direction in Fig. 9 correspond to the numbers of the four transducers 11. In the sequence in Fig. 9, the horizontal axis represents elapsed time, and the sequence up to time t2 shown in Fig. 8 is shown.

[0074] In each waveform, a low level indicates a state in which no voltage is applied to the ultrasound probe 12, and a high level indicates a wave packet to be applied. Here, the wave packet is as described above with reference to Figure 7. As shown in Figure 8, at time t1, cells 1 in all regions corresponding to transducers 11 numbers 1 to 4 are to be ablated, and therefore, as shown in Figure 9, wave packets are applied to four transducers 11 at time t1.

[0075] Next, the transducers 11 are scanned in the x-axis direction by the scanning mechanism 15. Thereafter, at time t2, cells 1 are detached in all regions corresponding to the transducers 11 numbered 1 and 4, so as shown in FIG. 9, wave packets are applied only to the two transducers 11 numbered 1 and 4 at time t2. Although the sequence from time t3 onwards is omitted, in this manner, cells 1 can be selectively detached in a desired detachment region 511 as shown in FIG. 8. As described above, according to this embodiment, by using a plurality of transducers 11, cells 1 can be selectively detached in a desired region of the cell adhesion surface in the culture vessel 2.

[0076] In this way, the cell detachment device 10 according to this embodiment can irradiate the cells 1 being cultured with an ultrasonic beam 13, thereby efficiently detaching the cells 1 in any shape and without contact from the culture vessel 2. In particular, the cell detachment device 10 according to this embodiment independently controls and scans the multiple transducers 11 aligned in the array axis direction with respect to the desired detachment region 511, thereby expanding the region irradiated with the ultrasonic beam 13 and enabling faster detachment.

[0077] (Arrangement of transducers) Here, the arrangement of the multiple transducers 11 will be described. Figures 10A to 10D are schematic diagrams illustrating an example of the array axis and scanning axis of the transducers 11. All of Figures 10A to 10D show the arrangement of multiple transducers 11. For the sake of simplicity, Figures 10A to 10D show a configuration using three transducers 11.

[0078] 10A shows a configuration in which the transducers 11 are arranged so that the long axis direction of the beam shape 310 of the ultrasonic beam 13 emitted on the cell adhesion surface is aligned with the array axis. The scanning axis along which the transducers 11 scan is perpendicular to the array axis. In other words, the beam shape 310 of the ultrasonic beam 13 emitted by the transducers 11 is flat, and the transducers are arranged so that the long axis of the flat shape is perpendicular to the scanning axis.

[0079] 10B shows a configuration in which the scanning axis is generally perpendicular to the array axis. In other words, the beam shape 310 of the ultrasonic beam 13 emitted by the transducer 11 is flat, and the transducer is arranged so that the long axis of the flat shape is generally perpendicular to the scanning axis. When the array axis is tilted by θ from the direction perpendicular to the scanning axis (y-axis), as described above, if the absolute value of θ is 40° or less, the rate of decrease in the cell detachment sweep area ΔS expressed by Equation 1 is small, and therefore the angle can be considered "generally perpendicular."

[0080] 10C shows a configuration in which adjacent transducers 11 are arranged to be offset from each other in the direction of the minor axis 322 of the flat beam shape 310, and to overlap in the direction of the major axis 321. That is, in FIG. 10C , adjacent transducers 11 are arranged so that the overlap amount Lov of the positions in the direction of the major axis 321 is positive (i.e., so that there is overlap). Arranging in this manner is more preferable, as it eliminates any peeling residue on adjacent transducers 11.

[0081] Fig. 10D shows a modified example of the configuration shown in Fig. 10C. Fig. 10D shows a configuration in which adjacent transducers 11 are arranged to be offset in the direction of the minor axis 322 of the flat beam shape 310, and are arranged to overlap in the direction of the major axis 321. That is, also in Fig. 10D, adjacent transducers 11 are arranged so that the amount of overlap Lov between their positions in the direction of the major axis 321 is positive. Even with this arrangement, it is possible to obtain the same effect as the configuration shown in Fig. 10C. Note that the arrangement of the transducers 11 is not limited to the configurations shown in Figs. 10A to 10D.

[0082] 1 , in this embodiment, a fluid 4 is placed inside a tank 5, and a culture vessel 2 is placed in the fluid 4. In this manner, an ultrasonic beam 13 emitted from a transducer 11 constituting an ultrasonic probe 12 is irradiated onto the culture vessel 2 via the fluid 4. By adopting a configuration in which the ultrasonic beam 13 is irradiated onto the culture vessel 2 via the fluid 4 in this manner, an effect of facilitating scanning of the ultrasonic beam 13 is obtained.

[0083] It is more preferable that the viscosity of the fluid 4 is 20 mPa·s or less, since this reduces the contact resistance during scanning. In this embodiment, water can be used as the fluid 4. The viscosity of water varies depending on the temperature, but is between 0.7 and 1.3 mPa·s.

[0084] In this specification, the distance between the ultrasound emission surface of the transducer 11 and the culture vessel 2 is defined as the gap length Lg. The gap between the ultrasound emission surface and the culture vessel 2 is filled with a fluid 4. In order for the ultrasound beam 13 to be efficiently irradiated onto the culture vessel 2, it is preferable that the gap length Lg be smaller than twice the wavelength λw of the ultrasound beam 13 in the fluid 4. That is, it is preferable to satisfy the following: Lg≦2×λw (Equation 3). Note that the wavelength λw of the ultrasound beam 13 is a quantity calculated using Equation 2. For example, when water is used as the fluid 4 and an ultrasound beam 13 with a fundamental frequency of 1 MHz is used, the wavelength λw in the fluid 4 is 1.5 mm, so the gap length Lg is preferably 3 mm or less. In this embodiment, Lg can be set to, for example, 1 mm.

[0085] (First Modification of First Embodiment) Next, a cell detachment device 10 according to a first modification of the first embodiment will be described. Fig. 11 is a schematic diagram of the cell detachment device 10 according to the first modification of the first embodiment. Fig. 12 is a schematic diagram showing an example of the configuration of the cell detachment device 10 according to the first modification of the first embodiment, and particularly explaining in detail an example of the configuration of the control unit 16. Note that this modification will be described mainly focusing on the differences from the first embodiment.

[0086] As shown in FIG. 11 , this modification differs from the first embodiment in that only one element driver 14 applies voltage to the transducer 11, and the transducer 11 to be driven is selectively switched by the switching unit 31 to irradiate the ultrasonic beam 13. Note that this modification differs from the first embodiment in that, as shown in FIG. 12 , the beam controller 53 is connected to one element driver 14. The beam controller 53 controls the conditions of the voltage applied to the element driver 14 based on the applied voltage and waveform determined by the beam condition determination unit 54. The beam controller 53 calculates the signal and intensity of the voltage applied to the ultrasonic probe 12. The switching unit 31 includes, for example, a relay circuit, and switches the transducers 11 that transmit the ultrasonic beam 13 determined by the control unit 16 in any order, applying voltage to each transducer 11 one by one. As in FIG. 1B , in the cell detachment device 10 according to this modification, the ultrasonic probe 12 scans in the direction of the minor axis 322 of the beam shape 310, i.e., the x-axis direction. According to this modification, the number of element driving sections 14 can be reduced, thereby reducing costs.

[0087] Next, a drive sequence of the four transducers 11 in the cell detachment device 10 shown in Figures 11 and 12 will be described. Figure 13 is a schematic diagram showing an example of time-series control of the transducers 11 in a first modification of the first embodiment. The drive sequence described here is a sequence for selectively detaching cells 1 in the detachment region 511 shown in Figure 8.

[0088] As shown in Figure 8, at time t1, cells 1 in all regions corresponding to transducers 11 numbered 1 to 4 are peeled off, so as shown in Figure 13, wave packets are applied sequentially to transducers 11 numbered 1 to 4 from time t1.

[0089] Next, the transducer 11 is scanned in the x-axis direction by the scanning mechanism 15. After that, at time t2, cells 1 in all regions corresponding to the transducers 11 numbered 1 and 4 are peeled off, so as shown in Figure 13, from time t2, wave packets are applied sequentially to the transducers 11 numbered 1 and 4.

[0090] In this modification, as an example, one wave packet is formed by 3,000 cycles of a fundamental wave with a fundamental frequency of 1 MHz. Therefore, the output time of one wave packet is 3 ms. Including the switching time in the relay circuit, the delay times of the wave packets of adjacent ultrasonic probes 12 are shifted by 10 ms when output. Therefore, the time required to drive four transducers 11 is 33 ms. Meanwhile, the time between time t1 and time t2 (the wave packet repetition period Tr) is preferably set to 1 second. Thus, in a typical example, the wave packet output time is sufficiently short compared to the wave packet repetition period Tr. Therefore, even if the voltage is switched and output sequentially, the required time is short, as shown in FIG. 13 . Although the sequence from time t3 onward is omitted, in this manner, cells 1 can be selectively detached in the desired detachment region 511 as shown in FIG. 8 . Thus, according to this modification, cells 1 can be selectively detached in the desired region of the cell adhesion surface in the culture vessel 2 by using multiple transducers 11. In this way, in the cell detachment device 10 according to this modified example, the number of element driving units 14 can be reduced, thereby reducing costs.

[0091] (Second Modification of First Embodiment) Next, a cell detachment device 10 according to a second modification of the first embodiment will be described. Fig. 14 is a schematic diagram of the cell detachment device 10 according to the second modification of the first embodiment. Note that this modification will be described mainly focusing on the differences from the first embodiment.

[0092] 14 , this modification differs from the first embodiment in that a beam variable mechanism 41 is provided in the ultrasonic probe 12, allowing the beam shape 310 of the ultrasonic beam 13 to be varied. The cell detachment device 10 according to this modification can adjust the intensity of the irradiated ultrasonic beam 13 using the beam variable mechanism 41. In other words, the cell detachment device 10 according to this modification can irradiate the ultrasonic beam 13 with varying intensity locally using the beam variable mechanism 41 to accommodate different adhesion states depending on the degree of adhesion of the cells 1. Therefore, the cell detachment device 10 according to this modification can efficiently detach the cells 1.

[0093] The beam variable mechanism 41 may be provided corresponding to the multiple transducers 11 that make up the ultrasonic probe 12. In this way, each transducer 11 can vary the beam shape 310, enabling more precise detachment of the cells 1. Furthermore, when the beam variable mechanism 41 is shared by multiple transducers 11, one beam variable mechanism 41 may be provided in the ultrasonic probe 12.

[0094] The beam variable mechanism 41 can be composed of, for example, one or more acoustic lenses. The acoustic lenses are controlled by the control unit 16 to change the focal position of the ultrasonic beam 13 in the transmission axis direction. The beam shape 310 of the ultrasonic beam 13 at the cell adhesion surface is flat with the major axis in the y-axis direction. In this modification, the beam shape 310 of the ultrasonic beam 13 at the cell adhesion surface is set to a rectangle. In the cell detachment device 10 according to this modification, similar to FIG. 1B , the ultrasonic probe 12 also scans in the direction of the minor axis 322 of the beam shape 310, i.e., in the x-axis direction. With this configuration, the cell detachment device 10 according to this modification can efficiently detach cells 1.

[0095] The output conditions of the ultrasonic beam 13, including the conditions for focusing the ultrasonic waves by the acoustic lens, are determined by the control unit 16. In this modification, a Fresnel lens may be provided to change the focus of the ultrasonic beam 13, and a voltage may be applied to the piezoelectric element 411 of the transducer 11 (see FIG. 2A, etc.) by modulating the frequency. In this case, the control unit 16 may determine the output conditions of the ultrasonic beam 13, including the Fresnel lens and the modulated frequency. In this way, the cell detachment device 10 according to this modification can vary the strength of the local ultrasonic beam 13, thereby enabling efficient detachment of cells 1.

[0096] Second Embodiment Next, a cell detachment device 10 and a cell detachment method according to a second embodiment will be described. Fig. 15 is a schematic diagram of the cell detachment device 10 according to the second embodiment. Fig. 16 is a schematic diagram showing an example of a database 52 containing ultrasonic irradiation conditions. The following description of this embodiment will focus on the differences from the first embodiment.

[0097] As shown in Figure 15, the cell detachment device 10 according to the second embodiment differs from the first embodiment in that it additionally includes a detection unit 51 that detects the detached state (adhesion state) of the cell 1. The cell detachment device 10 according to the second embodiment also differs from the first embodiment in that it includes a recognition unit 58 instead of the planning unit 59 in the first embodiment. This recognition unit 58 recognizes whether or not the cell 1 has been detached based on the information detected by the detection unit 51. Note that, like the first embodiment (see Figure 6), the cell detachment device 10 according to the second embodiment includes a database 52, a beam control unit 53, a beam condition determination unit 54, a scanning path calculation unit 55, an input unit 56, and a display unit 57.

[0098] Through various investigations, the present inventors have found that there is variation (unevenness) in the adhesion state of the cells 1. That is, the present inventors have found that there is a difference in adhesive force between the cells 1 and the cell adhesion surface depending on the location of the cell adhesion surface in the culture vessel 2. Therefore, depending on the intensity of the ultrasonic beam 13, after irradiation with one wave packet of the ultrasonic beam 13, the cells 1 may be separated into those that are detached and those that remain attached without being detached.

[0099] In the second embodiment, based on the experimentally confirmed fact that there is variation (unevenness) in the adhesion state of the cells 1, the presence or absence of detachment of the cells 1 is checked for each irradiation of the ultrasonic beam 13, and if detachment is not found, the ultrasonic beam 13 is irradiated again. In this way, in the second embodiment, detachment of the cells 1 can be achieved without leaving any detached cells 1 and with the irradiated ultrasonic energy reduced as much as possible. In the second embodiment, the intensity of the ultrasonic beam 13 can be reduced, so that detachment can be achieved without affecting the cells 1.

[0100] Note that each irradiation of the ultrasonic beam 13 means each irradiation of a wave packet of a burst wave. That is, in the second embodiment, after one wave packet is irradiated, the state of the cell 1 is detected by a detection unit 51 and a recognition unit 58 (to be described later) to determine the next ultrasonic irradiation position.

[0101] The detection unit 51 detects the detachment state of the cells 1. The detachment state refers to the state of how many cells 1 have detached within a predetermined area, and means, for example, the proportion of detached cells 1 within a predetermined area. The proportion of cells 1 in an adherent state is also an indicator of the detachment state. Since the proportion of adhered cells 1 (cells 1 in an adherent state) can be detected and converted into the detachment state, the detachment state may be detected by detecting the adhesion state.

[0102] The detection unit 51 may be, for example, an optical camera or an optical microscope. The detection unit 51 may also measure data such as the shape of the cell 1 and the coordinates of its edges, and store the data in the database 52. The recognition unit 58 recognizes the shape and detached state of the cell 1. For recognition, image processing using an image of the observed cell 1 may be used. Here, for example, the detached portion of the cell 1 vibrates when subjected to the acoustic force of the ultrasonic beam 13, but the portion of the cell 1 adhering to the cell adhesion surface does not vibrate even when subjected to the acoustic force of the ultrasonic beam 13. Therefore, the detached state of the cell 1 can be recognized by observing these states.

[0103] In their study, the inventors used an optical camera as the detection unit 51. The optical camera was installed on the upper side of the culture vessel 2. That is, the inventors installed the optical camera, which is the detection unit 51, on the opposite side to the side where the ultrasonic beam 13 is irradiated. Installing it on the opposite side has the effect of eliminating physical interference between the ultrasonic probe 12 and the optical camera, which is the detection unit 51. In the second embodiment, images taken before and after irradiation with the wave packet of the ultrasonic beam 13 are sent to the recognition unit 58. The recognition unit 58 detects the detachment state of the cells 1 by comparing the images taken before and after irradiation. That is, the recognition unit 58 determines the proportion of cells 1 that remain adhered without being detached (residual cells 1).

[0104] In the second embodiment, as described above, an optical camera is used as the detection unit 51 as an example, but the remaining cells 1 may be detected by using a reflected signal of the ultrasonic beam 13. In this way, the detection unit 51 may be any unit that detects the detached state of the cells 1. Note that, although the detection unit 51 is shown inside the control unit 16 in FIG. 15, the detection unit 51 may also be provided outside the control unit 16. That is, in the second embodiment, the cell detachment device 10 may be provided with the detection unit 51.

[0105] In the second embodiment, the following steps (operations) are appropriately set based on the proportion of cells 1 remaining after detachment. First, the database 52 saves (stores) data related to the shape (coordinate data) and adhesion state of the cells 1 recognized by the detection unit 51 and the recognition unit 58. The database 52 also stores the irradiation conditions of the ultrasonic beam 13, i.e., the control data of the ultrasound required for detaching the cells 1, such as the size, intensity, and transmission time of the ultrasonic beam 13, depending on the type of ultrasonic probe 12 (or transducer 11) used, the type of cultured cells, the number of days of culture, and the culture state. For example, as shown in FIG. 16 , the database 52 stores information such as the type of ultrasonic probe 12 (AA), the type of cultured cells (BB), the number of days of culture (CC), the applied voltage (DD~), the wave number (number of sine waves) of the ultrasonic beam 13 (HH~), the frequency (LL~), and the number of irradiations per location (PP~).

[0106] Next, the beam condition determination unit 54 sets the basic conditions for the irradiation conditions of the ultrasonic beam 13 based on the information in the database 52. The beam condition determination unit 54 determines the output of the ultrasonic beam 13 based on the irradiation conditions of the ultrasonic beam 13 stored in the database 52. Specifically, the beam condition determination unit 54 determines the voltage and waveform to be applied to the transducer 11 by the element driving unit 14. Here, the "output of the ultrasonic beam 13" includes the irradiation intensity of the ultrasonic beam 13 and a decision on whether to output the ultrasonic beam 13. Furthermore, the beam condition determination unit 54 may determine the conditions, as necessary, by referring to information on the detachment state of the cells 1 (detachment state information) obtained by the detection unit 51 and the recognition unit 58. For example, if residual cells 1 are generated by the first irradiation of the ultrasonic wave packet, the irradiation intensity of the second wave packet may be increased. Alternatively, if the proportion of residual cells 1 is small, the irradiation intensity of the second wave packet may be decreased compared to the first. Here, the irradiation intensity of the ultrasonic beam 13 is an amount determined by the voltage applied to the transducer 11, the number of cycles N that constitutes the wave packet, and the like.

[0107] The scanning path calculation unit 55 calculates a path for peeling a desired peeling region 511 of the cell 1. The scanning path starts from any coordinate of any element number and scans to fill the entire surface of the peeling region 511. Alternatively, the scanning path calculation unit 55 may perform scanning to peel the edge of the group of cells 1 detected by the detection unit 51 by irradiating the ultrasonic beam 13, and then irradiate the ultrasonic beam 13 to the boundary between the peeling region 511 from which the cells 1 have peeled and the adhesion region (non-peeled region 512). The scanning path calculation unit 55 can refer to information on the peeling state of the cell 1 (peeling state information) obtained by the detection unit 51. Specifically, if the cell 1 has not been sufficiently peeled in the current beam irradiation region, the scanning path calculation unit 55 (i.e., the control unit 16) determines a scanning path to irradiate the same region with the ultrasonic beam 13 again. If the cell 1 has been sufficiently peeled, the scanning path calculation unit 55 (i.e., the control unit 16) determines a scanning path to move to the next irradiation region.

[0108] If there are any remaining cells 1, the beam condition determination unit 54 and the scanning path calculation unit 55 may be configured so that only the corresponding transducers 11 among the plurality of transducers 11 irradiate the ultrasonic beam 13. For example, as shown in Figures 9 and 13, after irradiating the first wave packet at time t1, if the proportion of remaining cells 1 is high on the cell adhesion surface corresponding to the transducers 11 numbered 1 and 4, the second wave packet at time t2 may be irradiated only by the transducers 11 numbered 1 and 4. In this embodiment, since a configuration using a plurality of transducers 11 is used, the amount of irradiation energy of the ultrasonic beam 13 can be reduced.

[0109] The input unit 56 inputs data (information) specifying the region to be detached from the cells 1 on the cell adhesion surface of the culture vessel 2. For example, the input unit 56 can input information for cutting out a detached portion having a desired shape from the cells 1 being cultured, which is displayed on the display unit 57. The input unit 56 has a keyboard and a mouse, and is operated by an operator or the like to input information. The information such as the shape of the detached portion input from the input unit 56 is provided to the database 52 and the control unit 16.

[0110] The display unit 57 has a monitor screen and displays at least one of the actual image acquired by the detection unit 51, the exfoliated area 511, the shape of the exfoliated portion of the cell 1 (shape of the cell 1) input by the input unit 56, the mode of the ultrasound during irradiation, the scanning path, and the irradiation position. In this way, the operator or the like can obtain appropriate information.

[0111] (Variation of the embodiment: Updating the database) In yet another embodiment, the control unit 16 is provided with an external connection unit (not shown), which enables the information in the database 52 to be updated externally. Here, the "external connection unit" may be, for example, a unit that directly connects to an external storage device such as a hard disk drive, or may be a unit that connects to a network and performs updates from an external update database. This configuration is more preferable in that the information in the database 52 can be updated to the latest content.

[0112] (Cell detachment method) Next, one aspect of the cell detachment method according to this embodiment will be described with reference to Fig. 17. Fig. 17 is a flowchart illustrating one aspect of the cell detachment method according to this embodiment. As shown in Fig. 17, this aspect of the cell detachment method according to this embodiment includes a selection step S171, a scanning path calculation step S172, a movement step S173, and a detachment step S174.

[0113] In the selection step S171, the shape of the detachment region 511 to be detached from the cell 1 is selected. The selection step S171 can be performed by the input unit 56. In the scan path calculation step S172, a scan path of the transducer 11 corresponding to the shape selected in the selection step S171 is calculated. The scan path calculation step S172 can be performed by the scan path calculation unit 55. In the movement step S173, the transducer 11 is moved to the specified position calculated and determined in the scan path calculation step S172. The movement step S173 can be performed by the scanning mechanism 15. In the detachment step S174, a voltage is applied to the transducer 11, ultrasonic waves are generated from the transducer 11, and an ultrasonic beam 13 is irradiated to detach the cell 1 from the cell adhesion surface. The detachment step S174 can be performed by the beam condition determination unit 54, the beam control unit 53, the element driving unit 14, the ultrasonic probe 12, etc.

[0114] In one aspect of the cell detachment method according to this embodiment, the transducers 11 are arranged along an arbitrary array axis direction (see, for example, Figures 10A to 10D). The beam shape 310 of the ultrasonic beam 13 emitted by the transducer 11 is flat, and its long axis 321 is arranged (approximately) perpendicular to the scanning axis. Furthermore, in the movement step S173, the scanning mechanism 15 moves the position of the transducer 11 relative to the culture vessel 2, causing the transducer 11 to scan along a scanning axis direction different from the array axis direction. As a result, in one aspect of the cell detachment method according to this embodiment, as described with respect to the cell detachment device 10, the beam irradiation area when the ultrasonic beam 13 is scanned a certain distance is large, thereby enabling efficient non-contact detachment of the cells 1 from the culture vessel 2.

[0115] Next, another aspect of the cell detachment method according to this embodiment will be described with reference to Fig. 18. Fig. 18 is a flowchart illustrating another aspect of the cell detachment method according to this embodiment. As shown in Fig. 18, this aspect of the cell detachment method according to this embodiment includes a selection step S181, a scanning path calculation step S182, a movement step S183, a detachment step S184, a detection step S185, and an adjustment step S186.

[0116] Here, the selection step S181, the scanning path calculation step S182, the movement step S183, and the peeling step S184 in this other aspect are the same as the selection step S171, the scanning path calculation step S172, the movement step S173, and the peeling step S174 in the above-mentioned aspect, and therefore, a description thereof will be omitted, and only the detection step S185 and the adjustment step S186 will be described.

[0117] In the detection step S185, the detached state of the cell 1 at the location irradiated in the detachment step S184 is detected. The detection step S185 can be performed by the detection unit 51 and the recognition unit 58. In the adjustment step S186, the output conditions and irradiation position of the ultrasonic beam 13 for detaching the undetached cell 1 detected in the detection step S185 are adjusted. As described above, the adjustment step S186 can be performed by the beam condition determination unit 54 after detection by the detection unit 51 and the recognition unit 58.

[0118] In another aspect of the cell detachment method according to this embodiment, similar to the aspect described above, the transducers 11 are arranged along an arbitrary array axis direction (see, for example, Figures 10A to 10D). The beam shape 310 of the ultrasonic beam 13 emitted by the transducer 11 is flat, and its long axis 321 is arranged (approximately) perpendicular to the scanning axis. Furthermore, in the movement step S183, the scanning mechanism 15 moves the position of the transducer 11 relative to the culture vessel 2, causing the transducer 11 to scan along a scanning axis direction different from the array axis direction. As a result, in this other aspect of the cell detachment method according to this embodiment, as described for the cell detachment device 10, the beam irradiation area is increased when the ultrasonic beam 13 is scanned a certain distance, thereby enabling efficient non-contact detachment of the cells 1 from the culture vessel 2.

[0119] Next, a specific example of the cell detachment method according to this embodiment will be described with reference to Fig. 19. Fig. 19 is a flowchart illustrating the details of a specific example of the cell detachment method according to this embodiment. In the description of this specific example, multiple transducers 11 are used for independent scanning, but the scanning steps (movement steps S173 and S183) are shown as a flowchart of a detachment method for any one ultrasonic probe 12. The cell detachment method according to this embodiment is not limited to these, and is not limited to the following.

[0120] 19, first, the detachment conditions for the cell 1 are input to the input unit 56. The detachment conditions to be input include, for example, the selection of the region to be detached, the intensity of the ultrasonic beam 13 to be used for detachment, and the number of the transducer 11 to be used (step S191) (selection steps S171 and S181).

[0121] The scanning path calculation unit 55 reads out the coordinates of the arbitrary shape input in step S191 relative to the origin of the dissection area (the origin is, for example, the center of the culture vessel 2) stored in the database 52. Next, the scanning path calculation unit 55 calculates the transducer 11 (ultrasonic probe 12) corresponding to the shape selected in step S191 and its scanning path (step S192) (scanning path calculation steps S172 and S182).

[0122] Next, the scanning mechanism 15 changes the relative positions of the transducer 11 (ultrasonic probe 12) and the incubation vessel 2. Specifically, the scanning mechanism 15 moves the transducer 11 (ultrasonic probe 12) to a specified position so that the center of the ultrasonic beam 13 is positioned at the initial ultrasonic transmission point (origin) (step S193) (movement steps S173 and S183).

[0123] Next, the beam condition determination unit 54 adjusts and determines the intensity and number of times of the ultrasonic beam 13 based on the ultrasonic beam 13 stored in the database 52 and the irradiation conditions inputted in the input unit 56 (step S194).

[0124] Next, the element driving unit 14 applies a voltage to the transducer 11 of the ultrasonic probe 12 to generate ultrasonic waves and irradiate the ultrasonic beam 13, thereby detaching the cell 1 (step S195) (detachment steps S174, S184).

[0125] Next, the detection unit 51 measures the cell 1 at the location irradiated with the ultrasonic beam 13. Based on the measured data, the recognition unit 58 recognizes whether or not detachment has occurred (step S196) (detection step S185).

[0126] If the cell 1 is not detached (No in step S196), the process returns to step S194, where the beam condition determination unit 54 again determines the intensity and number of times of the ultrasonic beam 13 at the same coordinates (adjustment step S186). On the other hand, if a predetermined detachment rate or more of cells has been detached within the irradiated area (Yes in step S196), the scanning mechanism 15 moves to the next irradiation position (step S197). Then, when the ultrasonic beam 13 is irradiated over the entire cell 1 to detach the cell 1 from the culture vessel 2, the cell detachment process for one cell 1 is completed.

[0127] Thereafter, if other cells 1 are adhered within one culture vessel 2, or if cells 1 are cultured in other wells of a multi-well plate, the cell detachment device 10 moves the transducer 11 to the next position, that is, to another cell 1 or another well within one culture vessel 2, using the scanning mechanism 15. The cell detachment device 10 then performs the series of steps S191 to S197 described above, and is able to detach cells 1 of any shape from the cell adhesion surface of the culture vessel 2.

[0128] As described above, the cell detachment device 10 and cell detachment method according to this embodiment can irradiate the cells 1 being cultured with an ultrasonic beam 13, thereby efficiently detaching the cells 1 in any shape without contact from the culture vessel 2. In particular, by detecting the detached state of the cells 1, the number of times the ultrasonic beam 13 is irradiated onto the cells 1 can be reduced, thereby minimizing damage to the cells 1 being detached.

[0129] Illustrative aspects of this embodiment are described below. [Aspect 1] A cell detachment device for detaching cells from a cell adhesion surface of a culture vessel, comprising: a plurality of transducers for irradiating the cells with ultrasonic beams via the culture vessel; an element drive unit for applying voltage to piezoelectric elements of the transducers; a scanning mechanism for moving the positions of the transducers relative to the culture vessel; and a control unit for controlling whether or not to output the ultrasonic beams, the beam output intensity, and the positions of the transducers, wherein the transducers are arranged along an arbitrary array axis direction, and the scanning mechanism scans the transducers along a scanning axis direction different from the array axis direction. [Aspect 2] The cell detachment device according to Aspect 1, wherein the ultrasonic beams emitted by the transducers have a flat beam shape, and the major axis of the flat shape is arranged approximately perpendicular to the scanning axis direction. [Aspect 3] The cell detachment device according to Aspect 1, wherein a switching unit for switching the piezoelectric elements to be driven is included. [Aspect 4] The cell detachment device according to Aspect 1, wherein the transducers are equipped with a beam variable mechanism for focusing the ultrasonic beams. [Aspect 5] The cell detachment device of Aspect 4, characterized in that the beam variable mechanism includes one or more acoustic lenses that focus the ultrasonic beam, and the control unit determines the output conditions of the ultrasonic beam, including the focusing conditions of the ultrasonic beam by the acoustic lens. [Aspect 6] The cell detachment device of Aspect 4, characterized in that the beam variable mechanism includes a Fresnel lens that changes the focus of the ultrasonic beam, and the control unit determines the output conditions of the ultrasonic beam, including the voltage to be applied to the piezoelectric element by modulating the frequency. [Aspect 7] The cell detachment device of Aspect 1, characterized in that it includes a database containing output conditions for the beam output of the ultrasonic beam according to at least one of the type of cell and the type of culture vessel, and the control unit sets the output conditions of the ultrasonic beam by referring to the database. [Aspect 8] The cell detachment device of Aspect 7, characterized in that the control unit includes an external connection unit, and the information in the database is updated with external information via the external connection unit.[Aspect 9] The cell detachment device according to Aspect 1, further comprising a detection unit that detects the detachment state of the cells, and the control unit determines the output of the ultrasonic beam and the scanning path for moving the transducer based on detachment state information output by the detection unit. [Aspect 10] The cell detachment device according to Aspect 9, further comprising: detaching an edge of the cell group detected by the detection unit by irradiating the ultrasonic beam; and then irradiating the ultrasonic beam onto the boundary between the detached region where the cells have detached and the adhered region. [Aspect 11] The cell detachment device according to Aspect 1, further comprising a display unit that displays at least one of an actual image of the cells, the detached region, the shape of the cells, the mode of the ultrasonic beam, the scanning path, and the irradiation position. [Aspect 12] The cell detachment device according to Aspect 1, further comprising a fluid interposed between the culture vessel and the transducer. [Aspect 13] The cell detachment device according to Aspect 12, further comprising: water. [Aspect 14] The cell detachment device according to Aspect 1, wherein the element drive unit outputs a burst wave of a wave packet having a fundamental frequency f0, the fundamental frequency f0 being 150 kHz or more and 50 MHz or less. [Aspect 15] The cell detachment device according to Aspect 1, wherein the transducer emits a converging ultrasonic beam. [Aspect 16] The cell detachment device according to Aspect 1, wherein the culture vessel is placed in a tank containing a fluid, the space between the culture vessel and the transducer is filled with the fluid, and the gap length between the culture vessel and the transducer is not more than twice the wavelength of the ultrasonic beam in the fluid. [Aspect 17] The cell detachment device according to Aspect 1, wherein the array axis direction is approximately perpendicular to the scanning axis direction. [Aspect 18] The cell detachment device according to Aspect 2, wherein adjacent transducers are arranged to be offset from each other in the direction of the minor axis of the flat beam shape, and are arranged so that the amount of overlap between adjacent transducers is positive in the direction of the major axis. [Aspect 19] The cell detachment device according to Aspect 2, wherein the width of the short axis of the flat shape is 5 mm or less.[Aspect 20] A cell detachment method for detaching cells from a cell adhesion surface of a culture vessel, comprising: a selection step of selecting a shape of a detachment region to be detached from the cells; a scan path calculation step of calculating a scan path of a transducer corresponding to the shape selected in the selection step; a movement step of moving the transducer to a designated position calculated and determined in the scan path calculation step; and a detachment step of applying a voltage to the transducer, generating ultrasound from the transducer, and irradiating an ultrasound beam to detach the cells from the cell adhesion surface, wherein the transducers are arranged along an arbitrary array axis direction, and the movement step causes the transducer to scan along a scan axis direction different from the array axis direction using a scanning mechanism that moves the position of the transducer relative to the culture vessel. a moving step of moving the transducer to a designated position calculated and determined in the scanning path calculation step; a detachment step of applying a voltage to the transducer to generate ultrasound from the transducer and irradiate an ultrasound beam to detach the cells from the cell adhesion surface; a detecting step of detecting a detached state of the cells at the point irradiated in the detachment step; and an adjusting step of adjusting output conditions and irradiation position of the ultrasound beam for detaching the undetached cells detected in the detecting step, wherein the transducers are arranged along an arbitrary array axis direction, and the moving step causes the transducer to scan along a scanning axis direction different from the array axis direction using a scanning mechanism that moves the position of the transducer relative to the culture vessel. [Aspect 22] A cell detachment method according to Aspect 20 or Aspect 21, characterized in that the ultrasonic beam emitted by the transducer has a flat beam shape, and the long axis of the flat beam is positioned approximately perpendicular to the scanning axis direction.

[0130] The cell detachment device and cell detachment method according to the present invention have been described in detail above using embodiments. However, the present invention is not limited to the above-described embodiments and includes various modifications. For example, the above-described embodiments have been described in detail to clearly explain the present invention, and the present invention is not necessarily limited to those including all of the described configurations. Furthermore, it is possible to replace part of the configuration of one embodiment with the configuration of another embodiment, or to add the configuration of another embodiment to the configuration of one embodiment. Furthermore, it is possible to add, delete, or replace part of the configuration of each embodiment with other configurations. These embodiments and their modifications are included within the scope and spirit of the invention, and are also included in the scope of the invention and its equivalents as set forth in the claims.

[0131] REFERENCE SIGNS LIST 1 Cell 2 Culture vessel 4 Fluid 5 Tank 10 Cell detachment device 11 Transducer 13 Ultrasonic beam 14 Element driving unit 15 Scanning mechanism 16 Control unit 31 Switching unit 41 Beam variable mechanism 51 Detection unit 52 Database 310 Beam shape 321 Major axis 322 Minor axis 411 Piezoelectric element

Claims

1. A cell detachment device for detaching cells from a cell adhesion surface of a culture vessel, comprising: a plurality of transducers for irradiating ultrasonic beams to the cells through the culture vessel; an element driving unit for applying a voltage to piezoelectric elements of the transducers; a scanning mechanism for moving the position of the transducers relative to the culture vessel; and a control unit for controlling whether or not to output the ultrasonic beam, the beam output intensity, and the position of the transducers, wherein the transducers are arranged along an arbitrary array axis direction, and the scanning mechanism scans the transducers along a scanning axis direction different from the array axis direction.

2. The cell detachment device according to claim 1, characterized in that the ultrasonic beam emitted by the transducer has a flat beam shape, and the major axis of the flat beam is arranged approximately perpendicular to the scanning axis direction.

3. The cell detachment device according to claim 1, further comprising a switching unit for switching the piezoelectric element to be driven.

4. The cell detachment device according to claim 1, characterized in that the transducer is provided with a beam variable mechanism for focusing the ultrasonic beam.

5. The cell detachment device described in claim 1, further comprising a database having output conditions for the beam output of the ultrasonic beam according to at least one of the type of the cell and the type of the culture vessel, and the control unit sets the output conditions for the ultrasonic beam by referring to the database.

6. The cell detachment device according to claim 5, characterized in that the control unit is provided with an external connection unit, and information in the database is updated with external information via the external connection unit.

7. The cell detachment device described in claim 1, further comprising a detection unit that detects the detachment state of the cells, and the control unit that determines the output of the ultrasonic beam and the scanning path for moving the transducer based on the detachment state information output by the detection unit.

8. The cell detachment device according to claim 1, wherein a fluid is interposed between the culture vessel and the vibrator.

9. The cell detachment device according to claim 1, characterized in that the element driving unit outputs a burst wave of a wave packet having a fundamental frequency f0, the fundamental frequency f0 being 150 kHz or more and 50 MHz or less.

10. The cell detachment device described in claim 1, characterized in that the culture vessel is placed in a tank containing a fluid, the space between the culture vessel and the transducer is filled with the fluid, and the gap length between the culture vessel and the transducer is less than twice the wavelength of the ultrasonic beam in the fluid.

11. A cell detachment device as described in claim 2, characterized in that adjacent transducers are positioned with a shift from each other in the direction of the short axis of the flat beam shape, and are positioned so that the amount of overlap between the positions of adjacent transducers is positive in the direction of the long axis.

12. A cell detachment method for detaching cells from a cell adhesion surface of a culture vessel, comprising: a selection step of selecting a shape of a detachment area to be detached from the cells; a scanning path calculation step of calculating a scanning path of a transducer corresponding to the shape selected in the selection step; a movement step of moving the transducer to a specified position calculated and determined in the scanning path calculation step; and a detachment step of applying a voltage to the transducer, generating ultrasound from the transducer, and irradiating an ultrasonic beam to detach the cells from the cell adhesion surface, wherein the transducers are arranged along an arbitrary array axis direction, and the movement step causes the transducer to scan along a scanning axis direction different from the array axis direction by a scanning mechanism that moves the position of the transducer relatively to the culture vessel.

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