Cell observation device, method for operating cell observation device, and program for operating cell observation device

Abstract

This cell observation device is provided with a processor. The processor acquires flow path information, which is information pertaining to a flow path through which a cell suspension containing cells flows, and determines, on the basis of the flow path information, image acquisition conditions for acquiring an image of cells in the flow path.

Description

CELL OBSERVATION DEVICE, METHOD FOR OPERATION OF CELL OBSERVATION DEVICE, AND OPERATION PROGRAM FOR CELL OBSERVATION DEVICE

[0001] The technology of the present disclosure relates to a cell observation device, an operating method for a cell observation device, and an operating program for a cell observation device.

[0002] A cell culture system (see, for example, International Publication No. WO 2015 / 069616) is known that cultures cells using a culture vessel. The culture vessel contains a cell suspension in which cells are suspended in a culture medium. When culturing cells, it is necessary to appropriately determine process conditions for the culture process, such as temperature control of the culture vessel, concentration control of the cell suspension in the culture vessel, and control of components of the culture medium, such as vitamins and amino acids.

[0003] In order to determine appropriate process conditions, it is necessary to understand the cell quality, which is the state of the cells during cultivation, and take this understood cell quality into consideration. To achieve this, cells are extracted from the culture vessel during cultivation, transferred to a container such as a petri dish, and observed to determine cell quality. However, because this type of offline inspection is time-consuming and labor-intensive, inline inspection techniques are being considered, in which cells are observed inline while flowing through a flow channel during cultivation. Cell observation devices such as phase-contrast microscopes and 3D image measurement using digital holography technology are used.

[0004] However, when observing cells inline, there is a concern that image quality may be degraded due to the inclusion of the flow path in the image, in addition to the cells being observed. This degradation in image quality makes it difficult to accurately grasp cell quality, which may hinder the determination of appropriate process control conditions.

[0005] The technology of the present disclosure provides a cell observation device, an operating method for a cell observation device, and an operating program for a cell observation device that are capable of acquiring cell images with better image quality than conventional devices.

[0006] In order to achieve the above-mentioned objective, the cell observation device according to the technology of the present disclosure is a cell observation device equipped with a processor, which acquires flow path information, which is information about a flow path through which a cell suspension containing cells flows, and determines image acquisition conditions for acquiring images of cells in the flow path based on the flow path information.

[0007] The image acquisition conditions preferably include either imaging conditions for capturing images of cells in the flow channel or image processing conditions for performing image processing.

[0008] The photographing conditions preferably include at least one of the wavelength of the illumination light that illuminates the flow channel and the exposure conditions.

[0009] The flow path information preferably includes at least one of information regarding the structure and characteristics of the flow path.

[0010] The characteristics of the flow path preferably include the refractive index of the flow path member that constitutes the flow path.

[0011] The imaging device is provided for capturing images of the cells, and the imaging device is preferably an image measurement device that uses digital holography technology.

[0012] The system preferably includes an imaging device that captures images of cells, and a detection mechanism that detects the passage of cells in a section of the flow path upstream of the imaging device and detects at least one of the timing, number, and density of the passing cells and the size of the passing cell aggregates, and the processor determines the image acquisition conditions based on the detection results of the detection mechanism.

[0013] The processor preferably determines the image acquisition conditions based on at least one of the following information in addition to the flow path information: the type of cell; and the type of culture medium used for the cell suspension.

[0014] Furthermore, the processor preferably has a function of determining process conditions for the cell culture process based on the image.

[0015] The flow channel is preferably extracted from a culture vessel for culturing cells, and is a flow channel through which a cell suspension containing cells in the middle of culturing flows.

[0016] The method of operating a cell observation device according to the disclosed technology is a method of operating a cell observation device equipped with a processor, in which the processor acquires flow path information, which is information about a flow path through which a cell suspension containing cells flows, and determines image acquisition conditions for acquiring images of cells in the flow path based on the flow path information.

[0017] The operating program of a cell observation device according to the disclosed technology is an operating program of a cell observation device equipped with a processor, and causes the processor to execute processes including acquiring flow path information, which is information about a flow path through which a cell suspension containing cells flows, and determining image acquisition conditions for acquiring images of cells in the flow path based on the flow path information.

[0018] According to the technology of the present disclosure, cell images of better image quality than conventional ones can be obtained.

[0019] 1 is a diagram showing an overview of a cell culture system incorporating a cell observation device. FIG. 2 is a block diagram showing the hardware configuration of the cell observation device. FIG. 3 is a diagram showing a photographing unit using digital holography technology. FIG. 4 is a conceptual diagram showing the principle of interference fringe generation and an interference fringe image. FIG. 4 is a diagram showing the positional relationship between a flow path member and a photographing unit. FIG. 5 is an explanatory diagram of image acquisition conditions. FIG. 6 is a diagram showing how to determine the amount of illumination light according to the transmittance of a flow path member. FIG. 7 is a diagram showing how to determine the amount of illumination light according to the dimensions of a flow path. FIG. 8 is a diagram showing image processing conditions determined based on flow path information. FIG. 9 is a flowchart showing the operation procedure of the cell observation device. FIG. 10 is a diagram showing an overview of a cell observation device of a second embodiment. FIG. 11 is a diagram showing cell number-related information detected based on a photosensor. FIG. 12 is a diagram showing an example of using the timing of cell passage. FIG. 13 is a diagram showing an example of a state where cells have a high density. FIG. 14 is a diagram showing a cell aggregate. FIG. 15 is a diagram showing how to determine the amount of illumination light according to cell density, etc. FIG. 16 is a diagram showing how to determine the wavelength of illumination light according to the size of a cell aggregate. FIG. 17 is a diagram showing a cell observation device having a function of determining process control conditions.

[0020] 1, a cell observation device 11 is incorporated into a cell culture system 2. The cell culture system 2 contains a cell suspension 15 in which cells 13 are suspended in a culture solution 14, and includes a culture vessel 16 in which the cells 13 are cultured. In the cell culture system 2, the culture process of the cells 13 is appropriately managed.

[0021] To properly manage the culture process, it is necessary to determine appropriate process conditions, such as culture conditions. Culture conditions include the environmental conditions of the culture vessel 16, the conditions for replenishing components of the culture solution 14, and the timing of replacing the culture solution 14. The environmental conditions of the culture vessel 16 include the temperature of the culture vessel 16 and the agitation speed of the cell suspension 15 by the agitator 17. The conditions for replenishing components of the culture solution 14 include the amount and timing of replenishing components contained in the culture solution 14 by the addition device 18. Components of the culture solution 14 include a carbon source, vitamins, and amino acids. Management of the culture process includes state management of the cell suspension 15, such as removal of debris (dead cells and debris) from the cell suspension 15 and replacement of the culture solution 14. The culture controller 19 controls the culture process in this manner.

[0022] The cultured cells 13 or a product produced by the cells 13 are recovered from the culture vessel 16 for the next step through a culture recovery path 21. The process conditions also include the timing of recovery of the cultured cells 13.

[0023] In addition to the culture recovery path 21, an observation path 22 is provided in the culture vessel 16. A pump 23 is provided in the observation path 22, and the pump 23 extracts a cell suspension 15 containing cells 13 in the middle of culturing from the culture vessel 16. The cells 13 in the middle of culturing flowing through a flow path 29 of the observation path 22 are observed by the cell observation device 11.

[0024] The cell observation device 11 is used to grasp the cell quality of the cells 13 during culture in order to appropriately manage the culture process. That is, the cell observation device 11 performs in-line inspection of the cells 13 flowing through the flow path 29 of the observation path 22. Then, based on the cell quality of the cells 13 during culture, it is determined whether or not changes to process conditions, including culture conditions, are necessary and what changes to make are necessary. Furthermore, based on the cell quality, the timing for removing debris, the timing for replacing the culture medium 14, and the timing for recovering the culture product are determined.

[0025] The cell observation device 11 includes a control device 26 and a photographing unit 27. The photographing unit 27 is disposed on the observation path 22. The cells 13 flow through the observation path 22 and are photographed and stored in a storage section 30. Some of the cells 13 in the storage section 30 are returned to the culture vessel 16 and some are discarded, for example, depending on the state of the cells.

[0026] The photographing unit 27 has a light source 27A that emits illumination light L that illuminates the cell 13 to be observed, and an image sensor 27B that captures an optical image of the illuminated light source 27A. The cell observation device 11 is, for example, an image measurement device that uses digital holography technology. The cell observation device 11 measures, for example, an image that represents the three-dimensional shape of the cell 13. The image that represents the three-dimensional shape of the cell 13 is also called a three-dimensional image. By observing the three-dimensional shape of the cell 13, it is possible to more accurately grasp the cell quality. The photographing unit 27 is an example of an "imaging device" according to the technology of the present disclosure.

[0027] The image sensor 27B captures an interference fringe image 31 representing the interference state between the object light and the reference light as an optical image. The control device 26 controls the driving of the photographing unit 27 and performs image processing to reconstruct a cell image 32 representing the three-dimensional shape of the cell 13 based on the interference fringe image 31. The control device 26 determines image acquisition conditions for acquiring the cell image 32. The image acquisition conditions include the photographing conditions of the photographing unit 27 and image processing conditions for reconstructing the interference fringe image 31 into the cell image 32.

[0028] Furthermore, the cell observation device 11 acquires flow path information, which is information about the flow path 29 through which the cell suspension 15 flows, in the section of the observation path 22 where the photography unit 27 is located. Then, the cell observation device 11 determines image acquisition conditions based on the acquired flow path information.

[0029] The cell quality of the cells 13 during culture is determined based on the cell image 32 acquired by the cell observation device 11, and process conditions including the culture conditions for the above-mentioned culture process are determined based on the determined cell quality. The culture process is controlled by the culture control device 19 according to the determined process conditions.

[0030] 2 , in the cell observation device 11, the control device 26 is configured by, for example, a computer. The control device 26 includes a storage 50, a memory 51, a CPU (Central Processing Unit) 52, a communication unit 53, a display 54, and an input device 55. These are interconnected via a bus line 56.

[0031] The storage 50 is a hard disk drive built into the computer that constitutes the control device 26 or connected via a cable or network. Alternatively, the storage 50 is a disk array consisting of multiple hard disk drives. The storage 50 stores control programs such as an operating system, various application programs, and various data associated with these programs. Note that a solid state drive may be used instead of a hard disk drive.

[0032] The memory 51 is a work memory for executing processes by the CPU 52. The CPU 52 loads programs stored in the storage 50 into the memory 51 and executes processes in accordance with the programs, thereby providing overall control over each part of the computer.

[0033] An operating program 58 according to the technology of the present disclosure is also stored in the storage 50. The operating program 58 is an application program for causing a computer to function as the cell observation device 11. By executing the operating program 58, the CPU 52 works in cooperation with the memory 51 to function as a processor 61 according to the technology of the present disclosure.

[0034] The communication unit 53 is a network interface that controls the transmission of various information via a network such as a LAN (Local Area Network). The display 54 displays various screens. The computer that constitutes the control device 26 accepts input of operation instructions from an input device 55 via the various screens. The input device 55 is a keyboard, a mouse, a touch panel, etc.

[0035] 3, the photographing unit 27 includes a light source 27A, an image sensor 27B, and a photographing optical system 66. As is well known, digital holography is a technology that utilizes the coherence of light to record light phase information in addition to light intensity information of an object to be observed, and then reconstructs a three-dimensional image of the object by using the recorded intensity information and phase information.

[0036] Digital holography utilizes the coherence of light and therefore uses coherent laser light as illumination light L. Light source 27A is a laser light source that emits laser light as illumination light L. Image sensor 27B is a two-dimensional image sensor having an imaging surface on which light-receiving elements are arranged two-dimensionally, and may be, for example, a CMOS (complementary metal-oxide semiconductor) image sensor.

[0037] An imaging optical system 66 is disposed on the optical path from the light source 27A to the image sensor 27B. The imaging optical system 66 includes, for example, a first reflecting mirror 66A, a beam splitter 66B, a second reflecting mirror 66C, an imaging lens LZ, a third reflecting mirror 66D, and a beam combiner 66E. The first reflecting mirror 66A reflects illumination light L emitted by the light source 27A toward the beam splitter 66B. The beam splitter 66B splits the illumination light L into an object light path toward the second reflecting mirror 66C and a reference light path toward the third reflecting mirror 66D.

[0038] A flow path 29 through which the cells 13 pass is disposed within the object light path including the second reflecting mirror 66C, and illumination light L reflected by the second reflecting mirror 66C is irradiated onto the cells 13. The illumination light L transmitted through the flow path 29 and the cells 13 is incident on an imaging lens LZ as object light OL. The imaging lens LZ focuses the object light OL and forms an optical image of the focused object light OL on the imaging surface of the image sensor 27B via a beam combiner 66E.

[0039] On the other hand, the illumination light L traveling along the reference light path from the beam splitter 66B to the third reflecting mirror 66D is incident on the third reflecting mirror 66D without passing through the flow path 29 through which the cells 13 flow. The illumination light L reflected by the third reflecting mirror 66D is incident on the beam combiner 66E as the reference light RL. Then, the illumination light L passes through the beam combiner 66E and is incident on the image sensor 27B.

[0040] As conceptually shown in Figure 4, the object light OL that passes through the flow path 29 and the cell 13 is diffracted by the cell 13 and the material that makes up the flow path 29, resulting in a curved wavefront. On the other hand, the reference light RL that does not pass through the flow path 29 and the cell 13 is a plane wave because it is not diffracted by the cell 13 or the like. Furthermore, the object light OL has a phase difference with respect to the reference light RL, and this phase difference has a magnitude that depends on the refractive index of the material that makes up the cell 13 and the flow path 29. The object light OL and the reference light RL interfere on the imaging surface 27BA of the image sensor 27B, generating interference fringes 67. The image sensor 27B captures the interference fringes 67 and outputs an interference fringe image 31.

[0041] The pixel value of each pixel in the interference fringe image 31 is the intensity of the interference fringes 67. In other words, the interference fringe image 31 is a two-dimensional distribution of the intensities of the interference fringes 67. The intensity of the interference fringes 67 changes in the imaging plane 27BA (XY plane) according to the phase difference between the object light OL and the reference light RL.

[0042] Of the lines representing the object light OL and the reference light RL, the solid lines indicate the wavefronts of the object light OL and the reference light RL with the maximum amplitude. In contrast, the dashed lines indicate the wavefronts of the object light OL and the reference light RL with the minimum amplitude. The white dots 68 shown on the imaging plane 27BA are areas where the wavefronts of the object light OL and the reference light RL are aligned and constructive with each other. The areas of these white dots 68 appear as bright areas 67A in the interference fringes 67. In contrast, the black dots 71 shown on the imaging plane 27BA are areas where the wavefronts of the object light OL and the reference light RL are shifted by half a wavelength and destructive with each other. The areas of these black dots 71 appear as dark areas 67B in the interference fringes 67.

[0043] For example, a digital holography image reconstruction method uses a plurality of interference fringe images 31 captured by changing the optical path difference between the object light OL and the reference light RL. Furthermore, for the illumination light L, for example, interference fringe images 31 captured using three or more illumination light beams L with different wavelengths (see interference fringe images of wavelengths λ1, λ2, and λ3 shown in FIG. 9 ) are acquired. Based on these plurality of interference fringe images 31, a cell image 32 representing the three-dimensional shape of the cell 13 is reconstructed.

[0044] 5, the flow path 29 is formed in, for example, a flow path member 74. The flow path member 74 is a flat plate-like member that is transparent to the illumination light L and is made of, for example, plastic. The flow path 29 is formed, for example, by forming a groove in a part of the flow path member 74, and the formed groove is sealed with a lid. Such a flow path member 74 is also called a micro-flow path device, etc.

[0045] The illumination light L passes through the flow path member 74 and the cells 13. Furthermore, because a cell suspension 15 containing cells 13 flows through the flow path 29, the illumination light L also passes through the culture solution 14 other than the cells 13 in the cell suspension 15. In the example shown in Fig. 5, the cross-sectional shape of the flow path 29 perpendicular to the flow direction is rectangular. Of course, the cross-sectional shape of the flow path 29 may also be circular. Furthermore, the flow path member 74 need not be a flat member, but may be a tube or the like.

[0046] For example, the photographing unit 27 repeatedly photographs still images of the interference fringe image 31 at preset intervals, thereby photographing the interference fringe image 31 showing the cells 13 flowing through the flow channel 29. Of course, the interference fringe image 31 may also be recorded as a moving image.

[0047] 6, the processor 61 of the control device 26 functions as an image processing unit 61A and an image acquisition condition determination unit 61B. The image processing unit 61A acquires an interference fringe image 31 from the photographing unit 27 and reconstructs a cell image 32 based on the acquired interference fringe image 31. The image acquisition condition determination unit 61B determines image acquisition conditions including the photographing conditions of the photographing unit 27 and the image processing conditions of the image processing unit 61A.

[0048] The image acquisition condition determination unit 61B determines the imaging conditions and image processing conditions based on the flow path information. The flow path information includes information about the structure and characteristics of the flow path. The information about the structure of the flow path includes the shape and dimensions of the flow path 29. It may also include the shape and dimensions of the flow path member 74. The information about the characteristics of the flow path 29 includes the transmittance and refractive index of the flow path member 74. The transmittance and refractive index are characteristics that are determined depending on the material of the flow path member 74.

[0049] Furthermore, the image acquisition condition determination unit 61B acquires, as observation target information, the type of cell 13 and the type of culture solution 14. The image acquisition condition determination unit 61B determines image acquisition conditions based on the observation target information in addition to the flow channel information.

[0050] The photographing conditions include the exposure condition and the wavelength of the illumination light L. For the same amount of illumination light L, the lower the transmittance of the flow path member 74, the lower the exposure amount of the image sensor 27B. Furthermore, for the same amount of illumination light L, the larger the dimensions of the flow path 29, the lower the exposure amount of the image sensor 27B. This is because, for example, if the cross-sectional area of ​​the flow path 29, which is determined by the width and height of the flow path 29, is large, the amount of diffusion and attenuation of the illumination light L increases accordingly.

[0051] If the exposure amount is too low, the contrast of the cell image 32 will decrease. The exposure amount is determined according to the exposure time, which is the accumulation time for accumulating incident light in the image sensor 27B, and the exposure condition of the light amount of the illumination light L from the light source 27A. The image acquisition condition determination unit 61B determines the exposure conditions of the photographing unit 27, including the exposure time and the illumination light amount from the light source 27A, based on the transmittance of the flow path member 74, so as to obtain an appropriate exposure amount.

[0052] For example, as shown in FIG. 7 , the image acquisition condition determination unit 61B increases the amount of illumination light L as the transmittance of the flow path member 74 decreases. Also, as shown in FIG. 8 , the image acquisition condition determination unit 61B increases the amount of illumination light L as the dimensions of the flow path 29 increase. By controlling the exposure conditions in this manner, an appropriate exposure amount can be obtained regardless of the transmittance of the flow path member 74 and the dimensions of the flow path 29. This prevents a decrease in the contrast of the cell image 32 and improves image quality. For example, table data or functions showing the relationships shown in FIGS. 7 and 8 are stored in the storage 50, and the image acquisition condition determination unit 61B controls the exposure conditions based on the flow path information while referring to this data.

[0053] Furthermore, if the illumination light L is scattered significantly at the object of observation, the image quality will be reduced. The shorter the wavelength of the illumination light L, the more detailed the structure of the object of observation can be visualized, but the more scattering there will be, which may result in a reduction in image quality. Therefore, by increasing the wavelength of the illumination light L, it may be possible to reduce scattered light and suppress the reduction in image quality. Therefore, the image acquisition condition determination unit 61B determines the wavelength to be used as the illumination light L depending on the shape of the flow path 29 and the characteristics of the flow path member 74, such as the transmittance.

[0054] 9, the image processing conditions include conditions for specifying the region of the cell 13 to be subjected to image reconstruction processing in the interference fringe image 31, conditions for setting parameters in the image reconstruction processing, etc. As an example, three interference fringe images 31 having wavelengths λ1, λ2, and λ3 are used.

[0055] If the region AR of the cell 13 can be identified in the interference fringe image 31, it is possible to remove noise information, such as information about the flow path 29 other than the cell 13. This improves the image quality of the cell image 32. To identify the region AR, for example, the difference between the refractive index of the flow path member 74 and the refractive index of the cell 13 is used. In addition, the difference between the refractive index of the cell 13 and the refractive index of the culture solution 14 may also be used. Based on these refractive index differences, the region of the interference fringe 67 corresponding to the cell 13 can be identified in the interference fringe image 31.

[0056] Furthermore, as an example of image reconstruction processing in digital holography, the Fourier iterative phase retrieval method is used. The Fourier iterative phase retrieval method involves repeated calculations of Fourier transform and inverse Fourier transform while changing parameters, which requires a large amount of calculation and takes a very long time. If the area AR in which the cell 13 exists in the interference fringe image 31 is identified, the area where the repeated calculations are performed can be narrowed down to the area AR, thereby reducing the influence of noise. This also improves the image quality of the cell image 32. Furthermore, narrowing down the area AR when performing image processing also shortens the processing time for image processing.

[0057] In this way, the image acquisition condition determination unit 61B determines image acquisition conditions, including imaging conditions and image processing conditions, based on the flow path information and the observation target information. In this example, the observation target information is used in addition to the flow path information, but flow path information alone may be used. For example, even if the type of cell 13 and the type of culture solution 14 are not specified, the area AR may be appropriately identified by using the average values ​​of the refractive indexes of the cells 13 and the culture solution 14.

[0058] Such flow path information and observation target information are input to the control device 26 by, for example, manual operation by the operator via the input device 55. The flow path information may be the actual values ​​of the dimensions, transmittance, refractive index, etc. of the flow path 29, or representative values ​​that can identify these values. An example of the representative value is the model number of the flow path member 74. The representative values ​​of the transmittance and refractive index of the flow path 29 may be the material of the flow path member 74, etc. When these representative values ​​are input, the control device 26 obtains information such as the dimensions and refractive index corresponding to the representative values ​​from table data prepared in advance. In this way, the control device 26 obtains the flow path information. Observation target information is also similarly input to the control device 26 by manual operation.

[0059] The operation of the above configuration will be described with reference to the flowchart shown in Fig. 10. As shown in Fig. 10, first, in step ST100, the processor 61 of the control device 26 acquires flow path information. As the flow path information, flow path information related to the flow path 29 of the cell culture system 2 in which the cell observation device 11 is used is set. Observation target information is also similarly set in the cell observation device 11. Then, in step ST110, the processor 61 determines image acquisition conditions, including imaging conditions and image processing conditions, based on the acquired flow path information and observation target information.

[0060] In the cell culture system 2, when culture is started, a cell suspension 15 containing cells 13 is extracted from the culture vessel 16 during the culture. The extracted cell suspension 15 flows through the flow path 29 and is photographed by the photographing unit 27 in step ST120. The processor 61 acquires an interference fringe image 31 of the photographed cells 13. In step ST130, the processor 61 performs image reconstruction processing based on the acquired interference fringe image 31 to reconstruct a cell image 32. In step ST140, the processor 61 outputs the cell image 32 to the display 54. The processor 61 proceeds to step ST150 to determine whether or not the observation has ended, and repeats the above processing until the observation has ended.

[0061] The operator checks the cells 13 shown in the displayed cell image 32 and understands the cell quality. Then, depending on the cell quality, the operator determines the process conditions for the culture process and sets the determined process conditions in the culture control device 19. This allows the process conditions to be set and changed depending on the cell quality. As a result, appropriate cell culture is performed. Furthermore, the frequency of monitoring to check the cell quality may be changed depending on the cell quality, such as by increasing the number of times the cell quality is checked if the cell quality does not reach the target.

[0062] According to the cell observation device 11 according to the technology of the present disclosure, the processor 61 acquires channel information, which is information about the channel 29 through which the cell suspension 15 containing the cells 13 flows, and determines, based on the channel information, image acquisition conditions for acquiring an image of the cells 13 in the channel 29. In the case of an image acquired by digital holography, for example, the image according to the technology of the present disclosure is an interference fringe image 31 or a cell image 32 representing the three-dimensional shape of the cells 13. Therefore, the image quality of the cell image 32 representing the cells 13 in the channel 29 can be improved compared to when channel information is not used to determine the image acquisition conditions.

[0063] The improved image quality of the cell image 32 allows for accurate understanding of cell quality, thereby enabling appropriate determination of process conditions for the culture process. Observation of the cells 13 flowing through the flow channel 29 is also necessary when determining the cell quality of the cells 13 during culture. The technology disclosed herein is effective for observing the cells 13 in the flow channel 29 because it determines image acquisition conditions using flow channel information.

[0064] In the above embodiment, the image acquisition conditions include either imaging conditions for capturing images of the cells 13 in the flow channel 29 or image processing conditions for performing image processing. By including either the imaging conditions or the image processing conditions, a good cell image 32 can be acquired.

[0065] Furthermore, in the above embodiment, the region AR of the cell 13 is specified as an image processing condition. This allows noise other than that of the cell 13 to be reduced, thereby obtaining a cell image 32 with good image quality. Furthermore, when acquiring an image using digital holography technology, the range of image processing can be narrowed by specifying the region AR of the cell 13 in the interference fringe image 31. This allows the amount of calculation and processing time for image processing to be reduced.

[0066] In the above embodiment, the imaging conditions include at least one of the wavelength of the illumination light L that illuminates the flow path 29 and the exposure conditions. By appropriately selecting the wavelength of the illumination light L, scattering can be suppressed, making it possible to obtain a cell image 32 with good image quality. Furthermore, by including the exposure conditions, it is possible to obtain a cell image 32 with high contrast and good image quality.

[0067] Furthermore, in the above embodiment, the flow channel information includes at least one of information regarding the structure and characteristics of the flow channel 29. In the above embodiment, compared to when information regarding the structure and characteristics of the flow channel 29 is not available, the imaging conditions or image processing conditions can be appropriately determined. For example, in the interference fringe image 31 and the cell image 32, information other than the cells 13, such as the flow channel 29, becomes noise. During image processing, if the dimensions and shape of the flow channel 29 are known as information regarding its structure, it is easy to identify the region of the flow channel 29 in the interference fringe image 31 or the cell image 32, and therefore the information regarding the flow channel 29 as noise can be removed from the interference fringe image 31 or the cell image 32. Furthermore, if the transmittance of the flow channel member 74, for example, is known as a characteristic of the flow channel 29, the amount of illumination light L transmitted into the flow channel 29 can be estimated, enabling appropriate exposure control.

[0068] Furthermore, in the above embodiment, the flow channel information includes, as a characteristic of the flow channel 29, the refractive index of the flow channel member 74 that constitutes the flow channel 29. If the refractive index of the flow channel member 74 is known as a characteristic of the flow channel 29, it is possible to remove information about the flow channel 29 as noise from the interference fringe image 31 or the cell image 32 based on the refractive index difference with the cell 13.

[0069] Furthermore, in the above embodiment, the cell observation device 11 is equipped with an imaging device (for example, the imaging unit 27) that captures images of the cells 13, and the imaging device is an image measurement device that uses digital holography technology. As described above, when using an image measurement device that uses digital holography technology, the image acquisition conditions are important for improving image quality and the efficiency of image processing, and therefore the technology disclosed herein is very effective.

[0070] Furthermore, in the above embodiment, the processor 61 determines the image acquisition conditions based on the flow path information as well as information on at least one of the type of cells 13 and the type of culture medium 14 used in the cell suspension 15. In addition to the flow path information, the processor 61 can take into account the characteristics (transmittance, refractive index, etc.) according to the type of cell and the type of culture medium, thereby making it possible to determine more appropriate image acquisition conditions.

[0071] The photographing unit 27 is disposed in the observation path 22. The flow path 29 of the observation path 22 is extracted from the culture vessel 16 in which the cells 13 are cultured, and is a flow path through which a cell suspension 15 containing the cells 13 in the middle of culture flows. Therefore, it is possible to grasp the state of the cells in the middle of culture, and to control the process conditions of the culture process in the middle of cell culture.

[0072] The flow path 29 of the observation path 22 is a flow path for observing the cells 13 in the middle of culturing, and therefore, unlike the flow path of the culture recovery path 21 through which the cultured cells 13 flow, the range of changes in the cell quality of the cells 13 is wider. Therefore, when observing the cells 13 in the middle of culturing, it is more necessary to accurately grasp the cell quality than when observing the cultured cells 13, and the technology of the present disclosure is particularly effective.

[0073] 11 differs from the first embodiment in that it includes a photosensor 76 that is arranged upstream of the photographing unit 27 in the observation path 22. The rest of the configuration is the same as that of the first embodiment, except for the processing using the photosensor 76.

[0074] As an example, the photosensor 76 is a transmission type photosensor in which a light-emitting element 76A and a light-receiving element 76B are arranged opposite each other across the flow path 29 of the observation path 22. As is well known, the photosensor 76 receives detection light emitted by the light-emitting element 76A with the light-receiving element 76B. When an object such as a cell 13 passes between the light-emitting element 76A and the light-receiving element 76B, the object blocks part of the detection light, causing a change in the amount of light received by the light-receiving element 76B. The light-receiving element 76B outputs a detection signal according to the amount of received light to the processor 61. Note that a reflective photosensor may be used as the photosensor 76 instead of a transmission type photosensor.

[0075] 12, the processor 61 detects cell number-related information based on the detection signal received from the photosensor 76. The cell number-related information includes the timing of passage of the cells 13, the number of cells 13 passing within a certain period of time, the density of the cells 13 passing within a certain period of time, and the size of a cell aggregate 13S (see FIG. 15) formed by an aggregation of multiple cells 13.

[0076] The processor 61 can detect the timing of the passage of cells 13 passing through the photosensor 76 based on changes in the detection signal corresponding to the amount of light received from the photosensor 76. Furthermore, by counting the changes in the detection signal, the processor 61 can detect the number of cells 13 passing through the photosensor 76. Furthermore, by measuring the average period of the detection signal, which periodically changes when multiple cells 13 pass through the photosensor 76, the processor 61 can detect the density of multiple cells 13 passing within a certain period of time. Furthermore, the processor 61 can detect the size of the cell aggregate 13S by measuring the degree and duration of the drop in the detection signal. This is because the drop in the amount of light received by the light-receiving element 76B per unit time is greater and the drop continues for a longer period of time when a cell aggregate 13S passes than when a single cell 13 passes.

[0077] In this way, the photosensor 76 and the processor 61 detect at least one of the passage timing, number, and density of the cells 13 and the size of the cell aggregates in the section of the flow path 29 upstream of the photographing unit 27 (an example of a photographing device). That is, the photosensor 76 and the processor 61 are an example of a "detection mechanism" according to the technology of the present disclosure. Then, in the processor 61, the image acquisition condition determination unit 61B determines the image acquisition conditions based on the detection results of the detection mechanism.

[0078] 13 , the image acquisition condition determination unit 61B can determine the image acquisition timing, which is the image acquisition condition of the image acquisition unit 27. Specifically, the image acquisition condition determination unit 61B can determine the image acquisition timing t2 of the image acquisition unit 27 by detecting the passage timing t1 of the cell 13 passing through the photosensor 76. The flow velocity of the cell 13 can be estimated from the driving force of the pump 23. Therefore, by detecting the passage timing t1, the image acquisition timing t2 can be determined by calculating the time it takes for the cell 13, having passed through the photosensor 76, to reach the image acquisition unit 27 downstream of the flow path 29. Knowing the image acquisition timing t2 allows image acquisition to be performed only during the period when the cell 13 passes through the image acquisition unit 27, thereby reducing unnecessary image acquisition in which the cell 13 is not present.

[0079] Furthermore, for example, the image acquisition condition determination unit 61B determines exposure conditions as imaging conditions depending on the density of the cells 13 or the size of the cell aggregates 13S. As shown as an example in FIG. 14 , when the intervals between the passing cells 13 are shorter and the density of the cells 13 is higher than in FIG. 5 , the amount of illumination light L from the imaging unit 27 blocked by the cells 13 increases, which may result in a decrease in contrast. Furthermore, as shown as an example in FIG. 15 , when the cross-sectional area of ​​the flow path 29 is large, multiple cells 13 may aggregate within the flow path 29 and flow as a single cell aggregate 13S. When imaging such a cell aggregate 13S, the amount of illumination light L blocked is greater than when imaging a single cell 13, which may result in a decrease in contrast.

[0080] Therefore, as shown in FIG. 16 as an example, the image acquisition condition determination unit 61B performs control such as increasing the intensity of the illumination light L according to the density of the cells 13 or the size of the cell aggregate 13S. Of course, instead of increasing the intensity of the illumination light L, the exposure time may be lengthened. This allows an appropriate exposure amount to be obtained regardless of the density of the cells 13, etc. This suppresses a decrease in contrast and improves the image quality of the cell image 32. For example, the storage 50 stores table data or functions showing the relationships shown in FIGS. 16 and 17, and the image acquisition condition determination unit 61B controls the exposure conditions based on the flow path information while referring to this data.

[0081] Furthermore, the larger the size of the cell aggregate 13S, the more scattering of the illumination light L occurs, which may result in a deterioration in the image quality of the cell image 32. The scattered light may be suppressed by increasing the wavelength of the illumination light L. Therefore, as shown in FIG. 17 as an example, the image acquisition condition determination unit 61B increases the wavelength of the illumination light L as the size of the cell aggregate 13S increases.

[0082] In this way, the cell observation device 11 of the second embodiment can use the photosensor 76 to detect changes in the state of the cells 13 in the flow path 29 in real time, such as the number and density of the cells 13 flowing through the flow path 29, and determine appropriate exposure conditions according to the changes in the state of the cells 13.

[0083] The processor 61 may control the flow rate of the cells 13 to decrease in accordance with the timing of imaging, thereby suppressing blurring of the cell image 32. The flow rate of the cells 13 can be controlled by controlling the pump 23.

[0084] (Modification) In the above embodiment, the operator grasps the cell quality based on the cell image 32 output by the cell observation device 11, and determines the process conditions for the culture process based on the grasped cell quality. Such a function may be added to the cell observation device 11.

[0085] 18 , the processor 61 has a function of determining process conditions for a culture process of the cells 13 based on the cell image 32. The processor 61 executes a process condition determination process. In the process condition determination process, the processor 61 determines the cell quality of the cells 13 by performing image analysis on the cell image 32. Based on the determination result, the processor 61 determines the process conditions, including the above-mentioned culture conditions for the cells 13.

[0086] Furthermore, although an image measurement device using digital holography technology has been described as an example of the cell observation device 11, a phase-contrast microscope, a bright-field microscope, or the like may also be used as the cell observation device 11. For example, control of exposure conditions based on flow path information is also effective for phase-contrast microscopes and bright-field microscopes.

[0087] There are various modifications possible to the hardware configuration of the computer that constitutes the cell observation device 11. For example, the cell observation device 11 can be configured with multiple computers separated as hardware, for the purpose of improving processing capacity and reliability.

[0088] In this way, the hardware configuration of the computer of the cell observation device 11 can be changed as appropriate according to the required performance, such as processing power, safety, reliability, etc. Furthermore, not only the hardware, but also application programs such as the operating program 58 can of course be duplicated or stored in a distributed manner across multiple storage devices in order to ensure safety and reliability.

[0089] The above description further discloses the following techniques. [Supplementary Item 1] A cell observation device including a processor, wherein the processor acquires flow path information, which is information about a flow path through which a cell suspension containing cells flows, and determines image acquisition conditions for acquiring an image of cells in the flow path based on the flow path information. [Supplementary Item 2] The cell observation device according to Supplementary Item 1, wherein the image acquisition conditions include either imaging conditions for capturing an image of cells in the flow path or image processing conditions for performing image processing. [Supplementary Item 3] The cell observation device according to Supplementary Item 2, wherein the imaging conditions include at least one of the wavelength of illumination light that illuminates the flow path and exposure conditions. [Supplementary Item 4] The cell observation device according to any one of Supplementary Item 1 to Supplementary Item 3, wherein the flow path information includes at least one of information about the structure and characteristics of the flow path. [Supplementary Item 5] The cell observation device according to Supplementary Item 4, wherein the flow path information includes at least one of information about the structure and characteristics of the flow path. [Supplementary Item 6] The cell observation device according to any one of Supplementary Items 1 to 5, further comprising: an imaging device that captures images of cells, wherein the imaging device is an image measurement device using digital holography technology. [Supplementary Item 7] The cell observation device according to any one of Supplementary Items 1 to 6, further comprising: an imaging device that captures images of cells; and a detection mechanism that detects the passage of cells in a section of the flow path upstream of the imaging device, and detects at least one of the timing, number, and density of the passing cells and the size of the passing cell aggregates, wherein the processor determines the image acquisition conditions based on the detection results of the detection mechanism. [Supplementary Item 8] The cell observation device according to any one of Supplementary Items 1 to 7, wherein the processor determines the image acquisition conditions based on at least one of information on the type of cells and the type of culture medium used for the cell suspension, in addition to the flow path information. [Supplementary Item 9] The cell observation device according to any one of Supplementary Items 1 to 8, further comprising: a processing unit that processes the cells based on the image.[Supplementary Item 10] A cell observation device according to any one of Supplementary Items 1 to 9, wherein the flow path is extracted from a culture vessel in which cells are cultured, and through which a cell suspension containing cells in the middle of culture flows. [Supplementary Item 11] A method for operating a cell observation device equipped with a processor, wherein the processor acquires flow path information that is information relating to a flow path through which a cell suspension containing cells flows, and determines image acquisition conditions for acquiring an image of cells in the flow path based on the flow path information. [Supplementary Item 12] An operation program for a cell observation device equipped with a processor, which causes the processor to execute processes including acquiring flow path information that is information relating to a flow path through which a cell suspension containing cells flows, and determining image acquisition conditions for acquiring an image of cells in the flow path based on the flow path information.

[0090] In each of the above embodiments, the hardware structure of the processing units that perform various processes, such as the image processing unit 61A and the image acquisition condition determination unit 61B, may be any of the following processors: As described above, the various processors include the CPU 52, which is a general-purpose processor that executes software (operation program 58) to function as various processing units, as well as dedicated electrical circuits that are processors having a circuit configuration specifically designed to perform specific processes, such as a programmable logic device (PLD) that is a processor whose circuit configuration can be changed after manufacture, such as an FPGA (Field Programmable Gate Array), and an ASIC (Application Specific Integrated Circuit).

[0091] A single processing unit may be configured with one of these various processors, or may be configured with a combination of two or more processors of the same or different types (e.g., a combination of multiple FPGAs and / or a combination of a CPU and an FPGA).Furthermore, multiple processing units may be configured with a single processor.

[0092] Examples of configuring multiple processing units with a single processor include, first, a form in which one processor is configured with a combination of one or more CPUs and software, as typified by computers such as client and server, and this processor functions as multiple processing units. Second, a form in which a processor is used to realize the functions of the entire system including multiple processing units with a single IC (Integrated Circuit) chip, as typified by systems on chips (SoCs). In this way, various processing units are configured using one or more of the above-mentioned various processors as a hardware structure.

[0093] Furthermore, more specifically, the hardware structure of these various processors can be an electric circuit (circuitry) that combines circuit elements such as semiconductor elements.

[0094] The technology of the present disclosure can be appropriately combined with the various embodiments and various modifications described above. Furthermore, the technology is not limited to the above embodiments, and various configurations can be adopted as long as they do not deviate from the gist of the present disclosure. Furthermore, the technology of the present disclosure also covers, in addition to programs, storage media that non-temporarily store programs. Examples of storage media include computer-readable non-temporary storage media such as USB (Universal Serial Bus) memory, flexible disks, and CD-ROMs (Compact Disc Read Only Memory). The programs may also be provided online via a network such as the Internet. The technology of the present disclosure also covers, in addition to programs, program products. A program product includes any type of product for providing a program. Like a program, a program product may be provided stored on a computer-readable non-temporary storage medium or provided online.

[0095] The above-described description and illustrations are a detailed explanation of the parts related to the technology of the present disclosure and are merely an example of the technology of the present disclosure. For example, the above description of the configuration, functions, actions, and effects is an explanation of an example of the configuration, functions, actions, and effects of the parts related to the technology of the present disclosure. Therefore, it goes without saying that unnecessary parts may be deleted, new elements may be added, or replacements may be made to the above-described description and illustrations within the scope of the gist of the technology of the present disclosure. Furthermore, to avoid confusion and facilitate understanding of the parts related to the technology of the present disclosure, the above-described description and illustrations omit explanations of common technical knowledge that do not require particular explanation to enable the implementation of the technology of the present disclosure.

[0096] In this specification, "A and / or B" is synonymous with "at least one of A and B." In other words, "A and / or B" means that it may be only A, only B, or a combination of A and B. Furthermore, in this specification, the same concept as "A and / or B" is also applied when three or more things are expressed by connecting them with "and / or."

[0097] The disclosure of Japanese Patent Application No. 2024-026481, filed on February 26, 2024, is incorporated herein by reference in its entirety. In addition, all documents, patent applications, and technical standards described herein are incorporated herein by reference to the same extent as if each individual document, patent application, and technical standard was specifically and individually indicated to be incorporated by reference.

Claims

1. A cell observation device equipped with a processor, wherein the processor acquires flow path information, which is information about a flow path through which a cell suspension containing cells flows, and determines image acquisition conditions for acquiring images of the cells in the flow path based on the flow path information.

2. A cell observation device as described in claim 1, wherein the image acquisition conditions include either imaging conditions for taking images of the cells in the flow channel or image processing conditions for performing image processing.

3. The cell observation device according to claim 2, wherein the imaging conditions include at least one of the wavelength of the illumination light that illuminates the flow channel and exposure conditions.

4. The cell observation device according to claim 1, wherein the flow channel information includes at least one of information relating to the structure and characteristics of the flow channel.

5. The cell observation device according to claim 4, wherein the characteristics of the flow path include the refractive index of a flow path material that constitutes the flow path.

6. The cell observation device according to claim 1, further comprising an imaging device for capturing images of the cells, the imaging device being an image measurement device using digital holography technology.

7. A cell observation device as described in claim 1, comprising: an imaging device that captures images of the cells; and a detection mechanism that detects the passage of the cells in a section of the flow path upstream of the imaging device and detects at least one of the timing, number, and density of the passing cells and the size of the passing cell aggregates, and the processor determines the image acquisition conditions based on the detection results of the detection mechanism.

8. The cell observation device according to claim 1, wherein the processor determines the image acquisition conditions based on at least one of the following information in addition to the flow path information: the type of the cells; and the type of culture medium used for the cell suspension.

9. The cell observation device according to claim 1, wherein the processor further has a function of determining process conditions for the cell culture process based on the image.

10. The cell observation device according to claim 1, wherein the flow path is extracted from a culture vessel in which the cells are cultured, and is a flow path through which the cell suspension containing cells in the process of being cultured flows.

11. A method for operating a cell observation device equipped with a processor, wherein the processor acquires flow path information, which is information relating to a flow path through which a cell suspension containing cells flows, and determines image acquisition conditions for acquiring images of the cells in the flow path based on the flow path information.

12. An operating program for a cell observation device equipped with a processor, the operating program causing the processor to execute processes including: acquiring flow path information, which is information about a flow path through which a cell suspension containing cells flows; and determining image acquisition conditions for acquiring images of the cells in the flow path based on the flow path information.

Images