U.S. patent application number 13/788165 was filed with the patent office on 2013-10-03 for micro-particle sorting apparatus and method of determining a trajectory of an ejected stream carrying micro-particles.
This patent application is currently assigned to Sony Corporation. The applicant listed for this patent is SONY CORPORATION. Invention is credited to Yosuke Muraki, Akiko Tsuji.
Application Number | 20130258075 13/788165 |
Document ID | / |
Family ID | 49234449 |
Filed Date | 2013-10-03 |
United States Patent
Application |
20130258075 |
Kind Code |
A1 |
Muraki; Yosuke ; et
al. |
October 3, 2013 |
MICRO-PARTICLE SORTING APPARATUS AND METHOD OF DETERMINING A
TRAJECTORY OF AN EJECTED STREAM CARRYING MICRO-PARTICLES
Abstract
A flow cytometer includes apparatus for evaluating a trajectory
of an ejected stream that carries micro-particles. The stream may
be ejected from a micro-orifice of a micro-fluidic chip. The
apparatus includes an imaging device and at least one processor
configured to evaluate a trajectory of the ejected stream in at
least two directions, e.g., a focusing direction and a direction
transverse to the focusing direction. Based upon a detected
trajectory, the system may execute an alarm function if the
trajectory indicates an abnormal condition, or may move sample
collection containers to accommodate for measured deviations in the
trajectory of the ejected stream.
Inventors: |
Muraki; Yosuke; (Tokyo,
JP) ; Tsuji; Akiko; (Kanagawa, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SONY CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
Sony Corporation
Tokyo
JP
|
Family ID: |
49234449 |
Appl. No.: |
13/788165 |
Filed: |
March 7, 2013 |
Current U.S.
Class: |
348/61 |
Current CPC
Class: |
G01N 2015/144 20130101;
G01N 15/1404 20130101; G01N 15/14 20130101 |
Class at
Publication: |
348/61 |
International
Class: |
G01N 15/14 20060101
G01N015/14 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 30, 2012 |
JP |
2012080366 |
Claims
1. A flow cytometer comprising: a micro-orifice configured to eject
a fluidic stream; an imaging device configured to image an ejected
stream, the ejected stream being at least a portion of the fluidic
stream ejected from the micro-orifice; and at least one processor
configured to receive and process an image of the ejected stream
imaged by the imaging device, detect one or more contrasted spots
located centrally within the ejected stream, and evaluate a
trajectory of the ejected stream from the received image.
2. The flow cytometer of claim 1, wherein the ejected stream
comprises a continuous liquid stream or comprises a stream of
separated liquid droplets.
3. The flow cytometer of claim 2, further comprising: electrostatic
deflection apparatus configured to deflect the liquid droplets; and
charging apparatus configured to apply charges to individual liquid
droplets so that individual liquid droplets carrying
micro-particles may be sorted according to pre-selected sorting
criteria.
4. The flow cytometer of claim 2, further comprising automated
focusing apparatus, wherein the at least one processor is further
configured to measure a first brightness level within at least one
central region of the liquid stream or liquid droplets and a second
brightness level in at least one remaining portion of the liquid
stream or liquid droplets and control the focusing apparatus based
upon the measured first and second brightness levels so as to
change a focus of the received image.
5. The flow cytometer of claim 4, wherein the focus of the received
image is changed according to a contrast ratio computed from the
first and second brightness levels.
6. The flow cytometer of claim 1, wherein the at least one
processor is configured to evaluate the trajectory of the ejected
stream based upon an arrangement of one or more bright spots
detected within the image of the ejected stream.
7. The flow cytometer of claim 6, wherein the at least one
processor is configured to evaluate the trajectory by identifying a
line that connects the one or more bright spots.
8. The flow cytometer of claim 1, wherein the at least one
processor is further configured to compute an angle associated with
the trajectory of the ejected stream.
9. The flow cytometer of claim 8, wherein the computed angle is a
measure of deviation of the ejected stream from a predetermined
direction.
10. The flow cytometer of claim 8, wherein the at least one
processor is further configured to detect an abnormality in
operation of the flow cytometer if the computed angle is greater
than a predetermined threshold value.
11. The flow cytometer of claim 10, wherein the detected
abnormality is associated with a micro-fluidic chip having the
micro-orifice.
12. The flow cytometer of claim 10, wherein the at least one
processor is further configured to execute an alerting function if
the computed angle is greater than a predetermined threshold
value.
13. The flow cytometer of claim 1, further comprising movable
sample collection tubes that are configured to be moved in an
automated manner responsive to the at least one processor
determining that the trajectory of the ejected stream deviates from
a predetermined trajectory.
14. The flow cytometer of claim 1, wherein the at least one
processor is configured to calculate the trajectory of the ejected
stream in a focus direction based upon a first focus condition of a
first portion of the ejected stream and a second focus condition of
a second portion of the ejected stream.
15. The flow cytometer of claim 14, wherein the first focus
condition is evaluated by focusing a first bright spot centrally in
the ejected stream near a first end of the ejected stream and the
second focus condition is evaluated by focusing a second bright
spot centrally in the ejected stream near a second end of the
ejected stream.
16. The flow cytometer of claim 14, wherein the at least one
processor is configured to calculate the trajectory of the ejected
stream based upon a difference in positions associated with the
first focus condition and second focus condition.
17. The flow cytometer of claim 1, wherein the at least one
processor is further configured to identify a width of the ejected
stream in the received image and determine a diameter of the
micro-orifice based upon the identified width of the ejected
stream.
18. The flow cytometer of claim 1, wherein the micro-orifice is an
exit orifice of a micro-fluidic chip.
19. A trajectory evaluation system for an ejected stream of a flow
cytometer, the trajectory evaluation system comprising: an imaging
device configured to image the ejected stream, wherein the ejected
stream is at least at portion of a fluidic stream ejected from a
micro-orifice of the flow cytometer; and at least one processor
configured to receive and process an image of the ejected stream
imaged by the imaging device, detect one or more contrasted spots
located centrally within the ejected stream, and evaluate a
trajectory of the ejected stream from the received image based upon
the one or more contrasted spots.
20. A method of measuring a trajectory of an ejected stream in a
flow cytometer, the method comprising: imaging, with an imaging
device, the ejected stream, wherein the ejected stream is at least
a portion of a fluidic stream ejected from a micro-orifice of the
flow cytometer; receiving, by at least one processor, an image of
the ejected stream imaged by the imaging device; and processing, by
the at least one processor, the received image to detect one or
more contrasted spots located centrally within the ejected stream
and to evaluate a trajectory of the ejected stream based upon the
one or more contrasted spots.
Description
FIELD
[0001] The present technology relates to a micro-particle sorting
apparatus and a method of determining a trajectory of an ejected
stream of the micro-particle sorting apparatus. In particular, the
present technology relates to a micro-particle sorting apparatus
which automatically determines a trajectory of a fluid stream or
the like carrying micro-particles that is ejected from an
orifice.
BACKGROUND
[0002] There has been a micro-particle sorting apparatus (for
example, a flow cytometer) which detects characteristics of
micro-particles such as cells optically, electrically or
magnetically, and fractionates or sorts the micro-particles so as
to collect only micro-particles having predetermined
characteristics.
[0003] In fractionating the micro-particles with the flow
cytometer, first, a fluid stream (laminar flow of sample liquid and
sheath liquid containing cells) is generated from an orifice formed
in a flow cell, a vibration is applied to the orifice to transform
the fluid stream into a form of liquid droplets, and electric
charge is applied to the liquid droplets. Then, the movement
direction of the liquid droplets containing the micro-particles
discharged from the orifice is electrically controlled to collect
target micro-particles having the desired characteristics and
non-target micro-particles having characteristics other than those
desired are sorted into separate collection containers.
[0004] For example, in Japanese Unexamined Patent Application
Publication No. 2010-190680, which is incorporated herein by
reference, describes a microchip flow cytometer according to one
embodiment as, "a micro-particle sorting apparatus including: a
microchip in which a flow path through which liquid containing
micro-particles flows and an orifice through which the liquid
flowing through the flow path is discharged into a space outside
the chip are disposed; a vibrating element configured to transform
the liquid into a form of liquid droplets and discharge the liquid
droplets in the orifice; charge means for adding an electric charge
to the discharged liquid droplets; optical detection means for
detecting the optical characteristics of micro-particles which flow
through the flow path; a pair of electrodes provided so as to be
opposed to each other with the moving liquid droplets interposed
therebetween along a movement direction of the liquid droplets
discharged into the space outside the chip; and two or more
containers that collect the liquid droplets passing through between
the pair of electrodes".
SUMMARY
[0005] In a micro-particle sorting apparatus, it is desirable to
design fluid collection such that a fluid stream or liquid droplets
generated from an orifice formed in a flow cell or a microchip
enter inside a collection container. Accordingly, it is necessary
to prevent a deviation of the fluid stream or the liquid droplets
from an assumed direction. In the related art, the prevention of
the deviation has been performed by checking an ejected fluid
stream or the like with visual observation of a user, and problems
regarding reliability and stability were generated and depended
upon the experience level of the user. Further, performing the
determination of the deviation with visual observation was
extremely complicated in the configuration of the apparatus.
[0006] It is desirable to provide a micro-particle sorting
apparatus capable of automatically detecting a deviation of a
trajectory of an ejected fluid stream or liquid droplets that
carries the micro-particles.
[0007] In the present technology, the term "micro-particles"
broadly includes biologically-relevant micro-particles such as
cells, microorganisms, liposomes, and the like, and synthetic
particles such as latex particles, gel particles, industrial
particles, and the like.
[0008] The biologically-relevant micro-particles include
chromosomes, liposomes, mitochondria, organelles, and the like
configuring various cells. Cells include animal cells
(hematopoietic cells and the like) and plant cells. Microorganisms
include bacteria such as coli bacteria, viruses such as tobacco
mosaic virus, and fungi such as yeast cells. Biologically-relevant
micro-particles include nucleic acids, proteins, and
biologically-relevant macromolecules such as a complex thereof.
Industrial particles may be organic or inorganic high polymer
materials, metals and the like, for example. Organic polymer
materials include polystyrene, styrene-divinylbenzene,
polymethylmethacrylate and the like. Inorganic polymer materials
include glasses, silica, magnetic materials, and the like. Metals
include gold colloids, aluminum and the like. The shape of the
micro-particles is generally spherical, however it may be
non-spherical and the size, weight and the like thereof are not
particularly limited.
[0009] According to the present technology, a micro-particle
sorting apparatus which is capable of automatically detecting the
deviation of the trajectory of an ejected fluid stream or liquid
droplets is provided. According to some embodiments, a flow
cytometer comprises a micro-orifice configured to eject a fluidic
stream, and an imaging device configured to image an ejected
stream, wherein the ejected stream is at least a portion of the
fluidic stream ejected from the micro-orifice. The flow cytometer
may further include at least one processor that is configured to
receive and process an image of the ejected stream imaged by the
imaging device, detect one or more contrasted spots located
centrally within the ejected stream, and evaluate a trajectory of
the ejected stream from the received image. The ejected stream may
comprise a continuous liquid stream or comprise a stream of
separated liquid droplets. The micro-orifice may be an exit orifice
of a micro-fluidic chip.
[0010] In some embodiments, the flow cytometer may further comprise
electrostatic deflection apparatus configured to deflect the liquid
droplets, and charging apparatus configured to apply charge to
individual liquid droplets so that individual liquid droplets
carrying micro-particles may be sorted according to pre-selected
sorting criteria. In some embodiments, the flow cytometer may
further comprise automated focusing apparatus, wherein the at least
one processor is further configured to measure a first brightness
level within at least one central region of the liquid stream or
liquid droplets and a second brightness level in at least one
remaining portion of the liquid stream or liquid droplets and
control the focusing apparatus based upon the measured first and
second brightness levels so as to change a focus of the received
image. The focus of the received image may be changed according to
a contrast ratio computed from the first and second brightness
levels.
[0011] According to some embodiments, the at least one processor
may be configured to evaluate the trajectory of the ejected stream
based upon an arrangement of one or more contrasted spots detected
within the image of the ejected stream. The at least one processor
may be configured to evaluate the trajectory by identifying a line
that connects the one or more contrasted spots. In some
embodiments, the at least one processor may be configured to
compute an angle associated with the trajectory of the ejected
stream. The computed angle may be a measure of deviation of the
ejected stream from a predetermined direction. According to some
embodiments, the at least one processor may be further configured
to detect an abnormality in operation of the flow cytometer if the
computed angle is greater than a predetermined threshold value. The
detected abnormality may be associated with or attributed to a
micro-fluidic chip having the micro-orifice. In some embodiments,
the at least one processor may be further configured to execute an
alerting function if the computed angle is greater than a
predetermined threshold value.
[0012] In some embodiments, the flow cytometer may further comprise
movable sample collection tubes that are configured to be moved in
an automated manner responsive to the at least one processor
determining that the trajectory of the ejected stream deviates from
a predetermined trajectory.
[0013] According to some embodiments, the at least one processor
may be configured to calculate the trajectory of the ejected stream
in a focus direction based upon a first focus condition of a first
portion of the ejected stream and a second focus condition of a
second portion of the ejected stream. The first focus condition may
be evaluated by focusing a first contrasted spot centrally in the
ejected stream near a first end of the ejected stream and the
second focus condition is evaluated by focusing a second contrasted
spot centrally in the ejected stream near a second end of the
ejected stream. In some embodiments, the at least one processor may
be configured to calculate the trajectory of the ejected stream
based upon a difference in positions associated with the first
focus condition and second focus condition.
[0014] In some embodiments, the at least one processor may be
further configured to identify a width of the ejected stream in the
received image and determine a diameter of the micro-orifice based
upon the identified width of the ejected stream.
[0015] The foregoing embodiments and features of a flow cytometer
may be implemented in a flow cytometer in any combination.
[0016] Embodiments also include a trajectory evaluation system for
a flow cytometer. The trajectory evaluation system may comprise an
imaging device configured to image the ejected stream, wherein the
ejected stream is at least at portion of a fluidic stream ejected
from a micro-orifice of the flow cytometer. The trajectory
evaluation system may further comprise at least one processor
configured to receive and process an image of the ejected stream
imaged by the imaging device, detect one or more contrasted spots
located centrally within the ejected stream, and evaluate a
trajectory of the ejected stream from the received image. The
ejected stream may comprise a continuous liquid stream or comprise
a stream of separated liquid droplets. The micro-orifice may be an
exit orifice of a micro-fluidic chip.
[0017] According to some embodiments, the trajectory evaluation
system may include automated focusing apparatus, wherein the at
least one processor is further configured to measure a first
brightness level within at least one central region of the liquid
stream or liquid droplets and a second brightness level in at least
one remaining portion of the liquid stream or liquid droplets and
control the focusing apparatus based upon the measured first and
second brightness levels so as to change a focus of the received
image. The focus of the received image may be changed according to
a contrast ratio computed from the first and second brightness
levels.
[0018] According to some embodiments, the at least one processor
may be configured to evaluate the trajectory of the ejected stream
based upon an arrangement of one or more contrasted spots detected
within the image of the ejected stream. The at least one processor
may be configured to evaluate the trajectory by identifying a line
that connects the one or more contrasted spots. In some
embodiments, the at least one processor may be configured to
compute an angle associated with the trajectory of the ejected
stream. The computed angle may be a measure of deviation of the
ejected stream from a predetermined direction. According to some
embodiments, the at least one processor may be further configured
to detect an abnormality in operation of a flow cytometer if the
computed angle is greater than a predetermined threshold value. The
detected abnormality may be associated with or attributed to a
micro-fluidic chip having the micro-orifice. In some embodiments,
the at least one processor may be further configured to execute an
alerting function if the computed angle is greater than a
predetermined threshold value.
[0019] In some embodiments, the trajectory evaluation system may
provide a signal for moving movable sample collection tubes that
are configured to be moved in an automated manner responsive to the
at least one processor determining that the trajectory of the
ejected stream deviates from a predetermined trajectory.
[0020] According to some embodiments, the at least one processor
may be configured to calculate the trajectory of the ejected stream
in a focus direction based upon a first focus condition of a first
portion of the ejected stream and a second focus condition of a
second portion of the ejected stream. The first focus condition may
be evaluated by focusing a first contrasted spot centrally in the
ejected stream near a first end of the ejected stream and the
second focus condition is evaluated by focusing a second contrasted
spot centrally in the ejected stream near a second end of the
ejected stream. In some embodiments, the at least one processor may
be configured to calculate the trajectory of the ejected stream
based upon a difference in positions associated with the first
focus condition and second focus condition.
[0021] In some embodiments, the at least one processor may be
further configured to identify a width of the ejected stream in the
received image and determine a diameter of the micro-orifice based
upon the identified width of the ejected stream.
[0022] The foregoing embodiments and features of a trajectory
evaluation system may be implemented in a trajectory evaluation
system for a flow cytometer in any combination.
[0023] Embodiments also include a method of measuring a trajectory
of an ejected stream in a flow cytometer. The method may comprise
an act of imaging, with an imaging device, the ejected stream,
wherein the ejected stream is at least a portion of a fluidic
stream ejected from a micro-orifice of the flow cytometer. The
method may further include receiving, by at least one processor, an
image of the ejected stream imaged by the imaging device, and
processing, by the at least one processor, the received image to
detect one or more contrasted spots located centrally within the
ejected stream and to evaluate a trajectory of the ejected stream.
The ejected stream may comprise a continuous liquid stream or
comprise a stream of separated liquid droplets. The micro-orifice
may be an exit orifice of a micro-fluidic chip.
[0024] According to some embodiments, the method of measuring a
trajectory may include an act of automated focusing, wherein the at
least one processor measures a first brightness level within at
least one central region of the liquid stream or liquid droplets
and a second brightness level in at least one remaining portion of
the liquid stream or liquid droplets and controls focusing
apparatus based upon the measured first and second brightness
levels so as to change a focus of the received image. The focus of
the received image may be changed according to a contrast ratio
computed from the first and second brightness levels.
[0025] According to some embodiments, the method of measuring a
trajectory may comprise evaluating the trajectory of the ejected
stream, by the at least one processor, based upon an arrangement of
one or more contrasted spots detected within the image of the
ejected stream. The at least one processor may evaluate the
trajectory by identifying a line that connects the one or more
contrasted spots. In some embodiments, the at least one processor
may compute an angle associated with the trajectory of the ejected
stream. The computed angle may be a measure of deviation of the
ejected stream from a predetermined direction. According to some
embodiments, the at least one processor may detect an abnormality
in operation of a flow cytometer if the computed angle is greater
than a predetermined threshold value. The detected abnormality may
be associated with or attributed to a micro-fluidic chip having the
micro-orifice. In some embodiments, the at least one processor may
execute an alerting function if the computed angle is greater than
a predetermined threshold value.
[0026] In some embodiments, the method of measuring a trajectory
may include providing a signal, by the at least one processor, for
moving movable sample collection tubes that are configured to be
moved in an automated manner responsive to the at least one
processor determining that the trajectory of the ejected stream
deviates from a predetermined trajectory.
[0027] According to some embodiments, the method of measuring a
trajectory may include calculating the trajectory of the ejected
stream in a focus direction, by the at least one processor, based
upon a first focus condition of a first portion of the ejected
stream and a second focus condition of a second portion of the
ejected stream. The first focus condition may be evaluated by
focusing a first contrasted spot centrally in the ejected stream
near a first end of the ejected stream and the second focus
condition is evaluated by focusing a second contrasted spot
centrally in the ejected stream near a second end of the ejected
stream. In some embodiments, the at least one processor may
calculate the trajectory of the ejected stream based upon a
difference in positions associated with the first focus condition
and second focus condition.
[0028] In some embodiments, the method of measuring a trajectory
may further comprise identifying, by the at least one processor, a
width of the ejected stream in the received image and determining a
diameter of the micro-orifice based upon the identified width of
the ejected stream.
[0029] The foregoing embodiments and features of a method of
measuring a trajectory of an ejected stream in a flow cytometer may
be implemented in flow cytometer in any combination.
[0030] The foregoing and other aspects, embodiments, and features
of the present teachings can be more fully understood from the
following description in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0031] The skilled artisan will understand that the figures,
described herein, are for illustration purposes only. It is to be
understood that in some instances various aspects of the
embodiments may be shown exaggerated or enlarged to facilitate an
understanding of the embodiments. In the drawings, like reference
characters generally refer to like features, functionally similar
and/or structurally similar elements throughout the various
figures. The drawings are not necessarily to scale, emphasis
instead being placed upon illustrating the principles of the
teachings. The drawings are not intended to limit the scope of the
present teachings in any way.
[0032] FIG. 1 is a schematic diagram illustrating a configuration
of a sorting system of a micro-particle sorting apparatus (flow
cytometer) according to an embodiment of the present technology.
The flow cytometer may be configured as a microchip flow
cytometer.
[0033] FIGS. 2A and 2B are schematic diagrams illustrating a
configuration of an example of a microchip which is mountable on a
flow cytometer.
[0034] FIGS. 3A to 3C are schematic diagrams illustrating a
configuration of an orifice of a microchip.
[0035] FIG. 4 is a flowchart illustrating steps for determining a
trajectory of a fluid stream or the like of a flow cytometer.
[0036] FIGS. 5A and 5B are pictures showing an example of images
before and after focusing which are imaged by a droplet camera of a
flow cytometer.
[0037] FIGS. 6A and 6B are schematic diagrams showing images of
fluid streams having different widths from each other imaged by a
droplet camera of a flow cytometer.
[0038] FIGS. 7A and 7B are pictures showing an example of images of
a fluid stream and liquid droplets imaged by a droplet camera of a
flow cytometer.
[0039] FIGS. 8A and 8B are pictures showing an example of images of
a fluid stream and liquid droplets imaged by a droplet camera of a
flow cytometer.
[0040] FIGS. 9A and 9B are pictures showing an example of images of
liquid droplets imaged by a droplet camera of a flow cytometer.
[0041] FIGS. 10A and 10B are schematic diagrams showing an example
of images of fluid streams imaged by a droplet camera of a flow
cytometer.
[0042] The features and advantages of the present embodiments will
become more apparent from the detailed description set forth below
when taken in conjunction with the drawings.
DETAILED DESCRIPTION
[0043] Hereinafter, an embodiment according to the present
technology will be described with reference to the drawings. The
embodiment, which will be described hereinafter, is an example of
the representative embodiments of the present technology, and the
scope of the present technology is not narrowed by the embodiment.
The description will be in the following order.
[0044] 1. Apparatus Configuration of Micro-particle Sorting
Apparatus according to Embodiment of Present Technology
[0045] 1-1. Chip Loading Module
[0046] 1-2. Microchip
[0047] 1-3. Deflection Plate
[0048] 1-4. Collection Unit
[0049] 1-5. Droplet Camera
[0050] 1-6. Control Unit and the like
[0051] 2. Method of Determining a Stream Trajectory of
Micro-particle Sorting Apparatus according to Another Embodiment of
Present Technology
[0052] 2-1. Fluid Stream Generating Step S.sub.1
[0053] 2-2. Droplet Camera Z Axis Scanning and Fluid Stream Imaging
Step S.sub.2
[0054] 2-3. Focusing Step S.sub.3
[0055] 2-4. Center Line Detecting Step S.sub.4
[0056] 2-5. Displaying Step S.sub.5
[0057] 2-6. Orbital Direction Determining Step S.sub.6
[0058] 2-6-1. Z Axis Direction Determining Step S.sub.61
[0059] 2-6-2. X Axis Direction Determining Step S.sub.62
[0060] 2-7. Alerting Step S.sub.7
[0061] 2-8. Collection Tube Moving and Aligning Step S.sub.8
[0062] 3. Various Additional Embodiments
1. Apparatus Configuration of Micro-Particle Sorting Apparatus
According to Embodiment of Present Technology
[0063] FIG. 1 is a schematic diagram illustrating a configuration
of a sorting system of a micro-particle sorting apparatus 1
(hereinafter, also referred to as a "flow cytometer 1") according
to an embodiment of the present technology. According to one
embodiment, the flow cytometer is configured as a microchip flow
cytometer.
[0064] 1-1. Chip Loading Module
[0065] Reference numeral 11 in the drawing denotes a chip loading
module storing a microchip 2. The chip loading module 11 includes a
chip loading unit which performs transportation to store the
microchip 2 inserted from the outside to a predetermined position,
and a transporting liquid connecting unit which supplies sample
liquid, sheath liquid, and the like including micro-particles to
the stored microchip 2 (both not shown). In addition, the chip
loading module 11 includes a chip vibrating unit which is formed in
the microchip 2, and applies a vibration to the orifice 21
generating laminar flow (flow stream S) of sample liquid and sheath
liquid to transform the fluid stream S into a form of liquid
droplets and discharge the liquid droplets, and an electric charge
unit which applies an electric charge to the discharged liquid
droplets (both not shown).
[0066] 1-2. Microchip
[0067] FIGS. 2A to 3C show an example of the microchip 2 which is
mountable on the flow cytometer 1. FIG. 2A shows a schematic
diagram of the upper surface and FIG. 2B shows a cross-sectional
schematic diagram taken along the line IIB-IIB of FIG. 2A. FIGS. 3A
to 3C are diagrams schematically illustrating one configuration of
the orifice 21 of the microchip 2. FIG. 3A shows a schematic
diagram of the upper surface, FIG. 3B shows a cross-sectional
schematic diagram, and FIG. 3C shows a plan diagram. FIG. 3B is a
cross-sectional diagram taken along the line IIIB-IIIB of FIG.
2A.
[0068] The microchip 2 may be formed by bonding substrate layers 2a
and 2b on which a sample flow path 22 is formed. The sample flow
path 22 on the substrate layers 2a and 2b can be formed by
injection molding of thermoplastic resin using mold. For the
thermoplastic resin, existing plastics of the related art as
materials of the microchip such as polycarbonate,
polymethylmethacrylate resin (PMMA), cyclic polyolefins,
polyethylene, polystyrene, polypropylene, polydimethylsiloxane
(PDMS) or the like may be used.
[0069] The sample liquid is introduced to a sample inlet 23 from
the transporting liquid connecting unit and joins with the sheath
liquid which is introduced to a sheath inlet 24 from the
transporting liquid connecting unit to transport the liquid to the
sample flow path 22. The sheath liquid introduced from the sheath
inlet 24 is transported by dividing into two directions. Then, in
the joining portion with the sample liquid introduced from the
sample inlet 23, the sheath liquid joins with the sample liquid so
as to interpose the sample liquid from two directions. Accordingly,
in the joining portion, three-dimensional laminar flow is formed in
which the laminar flow of the sample liquid is positioned at the
center of the laminar flow of the sheath liquid.
[0070] Reference numeral 25 denotes a suction flow path for
removing clogging and bubbles by causing a negative pressure inside
the sample flow path 22 to counterflow temporarily, when clogging
and bubbles are generated in the sample flow path 22. At the one
end of the suction flow path 25, a suction outlet 251 which is
connected to a negative pressure source such as a vacuum pump or
the like through the transporting liquid connecting unit is formed,
and another end thereof is connected to the sample flow path 22 in
a communicating port 252.
[0071] The laminar flow width of the three-dimensional laminar flow
may be formed to be narrowed down in narrowing units 261 (see FIGS.
2A and 2B) and 262 (see FIGS. 3A to 3C) so that the area of the
perpendicular cross section with respect to the transporting liquid
direction becomes small gradually or in steps from the upstream to
the downstream in the transporting liquid direction. After that,
the three-dimensional laminar flow becomes the fluid stream S (see
FIG. 1) and is discharged from the orifice 21 provided at one end
of the flow path. In FIG. 1, the discharging direction of the fluid
stream S from the orifice 21 is shown as the positive Y axis
direction.
[0072] The characteristics of the micro-particles may be detected
between the narrowing unit 261 and the narrowing unit 262 of the
sample flow path 22. For example, in optical detection by a light
irradiation detecting unit (now shown), a laser is emitted with
respect to the micro-particles which are arranged in a line in the
center of the three-dimensional laminar flow to flow inside the
sample flow path 22, and scattering light and fluorescence
generated from the micro-particles are detected by one or more
light detectors.
[0073] A connecting unit of the sample flow path 22 and the orifice
21 is set as a straight unit 27 formed to be linear. The straight
unit 27 functions for ejecting the fluid stream S from the orifice
21 linearly in the positive Y axis direction.
[0074] The fluid stream S ejected from the orifice 21 may be
transformed into a form of liquid droplets by the vibration applied
to the orifice 21 by a chip vibrating unit. The orifice 21 is
opened in the end surface direction of the substrate layers 2a and
2b, and a cut-out portion 211 is provided between the opening
position and the end surface of the substrate layers. The cut-out
portion 211 is formed by cutting out the substrate layers 2a and 2b
between the opening position of the orifice 21 and the end surface
of the substrates so that a diameter L of the cut-out portion 221
is larger than a diameter 1 of the opening of the orifice 21 (see
FIG. 3C). It is desirable that the diameter L of the cut-out
portion 211 be formed to be larger by more than double the diameter
1 of the opening of the orifice 21 so as not to interrupt the
movement of the liquid droplets discharged from the orifice 21.
[0075] 1-3. Deflection Plates
[0076] Reference numerals 12 and 12 in FIG. 1 denote a pair of
deflection plates which are arranged to oppose each other by
interposing the fluid stream S (or the discharged liquid droplets)
which is ejected from the orifice 21 and imaged by a droplet camera
4 which will be described later. The deflection plates 12 and 12
include electrodes which control the movement direction of the
liquid droplets discharged from the orifice 21 by an electric force
interacting with electric charge applied to the liquid droplets. In
addition, the deflection plates 12 and 12 also control the
trajectory of the fluid stream S generated from the orifice 21 by
an electric force interacting with electric charge applied to the
fluid stream S. In FIG. 1, the opposing direction of the deflection
plates 12 and 12 is shown as the X axis direction.
[0077] 1-4. Collection Unit
[0078] In the flow cytometer 1, the fluid stream S (or liquid
droplets D thereof) may be collected in any of a plurality of
collection tubes (collection containers) 3 which are arranged in a
line in the opposing direction (X axis direction) of the deflection
plates 12 and 12 (see FIG. 1). The collection tubes 3 may be
general-purpose plastic tubes or experimental glass tubes. The
number of the collection tubes 3 is not particularly limited, but
the embodiment shows a case of arranging five collection tubes. The
fluid stream S generated from the orifice 21 is introduced to any
one of the five collection tubes 3 depending on the existence or
non-existence, or the size of the electric force acting between the
deflection plates 12 and 12 and collected therein.
[0079] The collection tubes 3 may be disposed in a collection tube
container 31 in an exchangeable manner. The collection tubes 3 are
disposed in the movement direction (X axis direction) shown as an
arrow F1 in FIG. 1 in a movable manner. For example, the collection
tubes 3 may be disposed so that only the collection tubes 3 move in
the X axis direction in a state where the collection tube container
31 is fixed, or the collection tubes 3 may be disposed movably with
the movement of the collection tube container 31.
[0080] The collection tube container 31 may be disposed on a Z axis
stage 32 which is configured to be movable in a direction (Z axis
direction) perpendicular to the discharging direction (Y axis
direction) of the fluid stream S from the orifice 21 and the
opposing direction (X axis direction) of the deflection plates 12
and 12. An arrow F2 in FIG. 1 denotes the movement direction of the
Z axis stage 32. Reference numeral 321 in the drawing denotes a
waste liquid port provided on the Z axis stage 32. In the flow
cytometer 1, the collection tube container 31 and the Z axis stage
32 configure a collection unit 33 which is driven by a Z axis motor
(not shown).
[0081] 1-5. Droplet Camera
[0082] A droplet camera 4 may be any suitable camera (CCD camera,
CMOS image sensor or the like) for imaging the fluid stream S
ejected from the orifice 21 of the microchip 2 or the liquid
droplets discharged therefrom (see FIG. 1). The droplet camera 4
may be designed to be able to perform automated focusing under the
control of at least one processor on the captured image of the
fluid stream S or the liquid droplets. The image captured by the
droplet camera 4 may be displayed on the display unit such as a
display, and used for a user to check for the formation state
(size, shape, intervals and the like of the liquid droplets) of the
liquid droplets of the orifice 21.
[0083] In the flow cytometer 1, the trajectories of the fluid
stream S (or liquid droplets) ejected from the orifice 21 are
different depending on the individual differences of the mounted
microchips 2, and the position of the fluid stream S can be changed
in the Z axis direction (and X axis direction) in the drawing, at
each time of exchanging the microchip 2. Continuing ejecting the
fluid stream S or continuing discharging the liquid droplets may
result in the degradation or the like of the microchip 2, so that
the position of the fluid stream S (or the liquid droplets) can be
changed over time in the Z axis direction (and X axis direction) in
the drawing. The droplet camera 4 also functions for detecting such
position change of the fluid stream S (or the liquid droplets) in
the Z axis direction (and X axis direction).
[0084] 1-6. Control Unit and the Like
[0085] In addition to the above described configuration, the flow
cytometer 1 includes a light irradiation detecting unit for
detecting the optical characteristics of micro-particles, a data
analysis unit for determining the characteristics, a tank unit
which stores the sample liquid and the sheath liquid, and a control
unit for controlling each configuration thereof, which are included
in general flow cytometers.
[0086] The control unit may be configured by a general-purpose
computer including at least one CPU, a memory or a hard disk and
the like, and an OS. Machine-readable instructions that may be
executed by the at least one CPU may be stored in memory and, when
executed by the at least one CPU, specially adapt the computer for
executing each step of the position control, which will be
described later, and other processes of the flow cytometer.
[0087] The light irradiation detecting unit may be configured by a
laser light source, an irradiation system which includes a
condensing lens, a dichroic minor, a bandpass filter and the like
which condense and emit the laser with respect to the
micro-particles, and a detecting system which detects the measuring
target light generated from the micro-particles by excitation of
the laser. The detecting system may be configured by an area
imaging device or the like such as a PMT (photomultiplier tube), a
CCD, or a CMOS element.
[0088] The measuring target light which is detected by the
detecting system of the light irradiation detecting unit is the
light which is generated from the micro-particles by the emission
of the measuring light, and can be scattered light such as
forward-scattered light, backward-scattered light,
Rayleigh-scattered or Mie scattered light, or fluorescence. The
above measuring target light is converted into electrical signals,
output to the control unit and provided for determining the optical
characteristics of the micro-particles.
[0089] The flow cytometer 1 may magnetically or electrically detect
the characteristics of the micro-particles. In this case,
microelectrodes are arranged to oppose each other in the sample
flow path 22 of the microchip 2, and a resistance value, a
capacitance value, an inductance value, impedance, a changing value
of the electric field between the electrodes, or the change in
magnetization, magnetic field, and the like are measured.
2. Method of Determining a Stream Trajectory of Micro-Particle
Sorting Apparatus According to Another Embodiment of Present
Technology
[0090] 2-1. Fluid Stream Generating Step S.sub.1
[0091] FIG. 4 is a flowchart illustrating steps for determining the
trajectory of the fluid stream S (or the liquid droplets) of the
flow cytometer 1, according to one embodiment. The steps for
determining the trajectory include processes of a "fluid stream
generating step S.sub.1," a "droplet camera Z axis scanning and
fluid stream imaging step S.sub.2," a "focusing step S.sub.3," a
"center line detecting step S.sub.4," a "displaying step S.sub.5,"
an "orbital direction determining step S.sub.6," an "alerting step
S.sub.7," and a "collection tube moving and aligning step S.sub.8."
Hereinafter, each process will be described.
[0092] First, in the fluid stream generating step S.sub.1, the
transporting liquid connecting unit starts transporting the sample
liquid and the sheath liquid to the sample inlet 23 and the sheath
inlet 24 of the microchip 2, and a fluid stream S is ejected from
the orifice 21 (see FIG. 4). The control unit outputs the signals
to the transporting liquid connecting unit and starts transporting
the sample liquid and the sheath liquid. The fluid stream S ejected
from the orifice 21 may be collected in the waste liquid port 321
and disposed of.
[0093] In this step S.sub.1, the chip vibrating unit applies the
vibration to the orifice 21, and the liquid droplets may be
discharged instead of a continuous fluid stream S from the orifice,
so that the liquid droplets can be collected in the waste liquid
port 321 and disposed of.
[0094] 2-2. Droplet Camera Z Axis Scanning and Fluid Stream Imaging
Step S.sub.2
[0095] In the step S.sub.2, the control unit outputs the signals to
the droplet camera 4 and the droplet camera 4 which receives the
signals may be moved in the Z axis direction (see FIG. 4), for
example, to center an image of the stream. Then, the control unit
outputs the signals to the droplet camera 4, and the droplet camera
4 which receives the signals performs imaging of the fluid stream S
(or the liquid droplets).
[0096] 2-3. Focusing Step S.sub.3
[0097] In the step S.sub.3, in a case where the image of the fluid
stream S (or the liquid droplets) is detected, by the control unit,
the focusing may be performed in the X axis direction when imaging
the image of the fluid stream S (or the liquid droplets) by the
droplet camera 4 (see FIG. 4). The image of the fluid stream S (or
the liquid droplets) imaged by the droplet camera 4 may be output
to the control unit, and the control unit may perform focusing
control until detecting the contrasted or bright points in the
image in the focusing step S.sub.3. Herein, the bright points
denote one or a plurality of pixels having higher brightness than a
predetermined threshold value in the image of the fluid stream S
(or the liquid droplets) imaged by the droplet camera 4. A
contrasted point or spot may be a spot having a luminance or color
significantly different (e.g., greater than about 10% variation)
from a background luminance or color around the spot. For example,
a contrasted spot may be a gray spot on a white background, a
yellow spot on a red background, a white spot on a black
background, etc. in a recorded image.
[0098] FIG. 5A represents a picture showing an example of a state
before the focusing of the imaged liquid droplets is performed (see
FIG. 5A), and FIG. 5B represents a picture showing an example of a
state after the focusing of the liquid droplets is performed (see
FIG. 5B). As shown in FIG. 5B, since the focusing of the image P is
performed, it is possible to detect at least one bright point B in
the center position of each liquid droplet D. Even in a case where
the fluid stream S is ejected instead of the liquid droplets D from
the orifice, it is possible to detect at least one bright point B
in the center portion along the trajectory of the fluid stream S in
the same manner. Accordingly, in the step S.sub.4, the focusing of
the droplet camera 4 is executed until at least one bright point B
is detected in the captured image P. At that time, in a case where
the contrast ratio of the image P is in a predetermined range, the
control unit can determine whether the image P is in a focused
state.
[0099] When the fluid stream S is imaged by the droplet camera 4,
the control unit may determine the diameter of the orifice, based
on the width of the fluid stream S detected in the direction
perpendicular (Z axis direction) to the trajectory of the fluid
stream S in the captured image P.
[0100] FIGS. 6A and 6B show schematic diagrams of two captured
images which have a different width of the fluid stream S from each
other (FIGS. 6A and 6B). The control unit may be configured to
determine accurately that the diameter of the orifice is 100 .mu.m
or the like, for example, by evaluating the width of the fluid
stream S shown in FIG. 6A based on information stored in a memory
unit. In the example shown in FIG. 6B, which has different width of
the fluid stream S from that shown in FIG. 6A, the control unit may
be configured to determine accurately that the diameter of the
orifice is 70 .mu.m or the like, for example, by evaluating the
width of the fluid stream S based on the information stored in the
memory unit. The control unit may record or display the determined
diameter of the orifice as the diameter of the orifice of the chip
used in the flow cytometer 1. Accordingly, a manual setting or
recording of the diameter of the orifice by a user is not
necessary, and thus it is possible to prevent setting mistakes such
as mis-setting or mis-recording the diameter of the orifice.
[0101] 2-4. Center Line Detecting Step S.sub.4
[0102] In the step S.sub.4, the control unit may detect a center
line of the fluid stream S from one or more bright points in the
image of the fluid stream S (or the liquid droplets D) imaged by
the droplet camera 4, and may compare preset center line
information with the detected center line (see FIG. 4).
[0103] FIGS. 7A and 7B show states when a center line L of the
fluid stream S (or the liquid droplets D) is detected in the
captured image. When the fluid stream S is ejected from the
orifice, the control unit may be configured to detect the straight
line formed by the plurality of bright points displayed along the
ejecting direction of the fluid stream S in the image of the fluid
stream S imaged by the droplet camera 4 as the center line L. In
detail, as shown in FIG. 7A, the control unit may identify the
bright points B in the captured image P of the fluid stream S as
the center line L.
[0104] When the liquid droplets D are discharged from the orifice,
the control unit may be configured to detect a straight line formed
by connecting one or more bright points displayed in each of the
liquid droplets D as the center line L. In detail, as shown in FIG.
7B, when the liquid droplets D are imaged, the control unit may
identify a line formed by connecting the bright points of each of
the liquid droplets as the center line L of the liquid droplets. In
this case, according to the connecting method of the bright points
of each of the liquid droplets D, when a plurality of center lines
L can be generated, the control unit may set a line which most
closely approximates the center line information which will be
described later, as the center line.
[0105] 2-5. Displaying Step S.sub.5
[0106] In the step S.sub.5, the control unit can display the
captured image on a display unit such as a display monitor (see
FIG. 4).
[0107] As shown in FIGS. 7A and 7B, the control unit can arrange
and display the fluid stream S (see FIG. 7A) or the liquid droplets
D (see FIG. 7B) of the captured image in the center of such a
display based on the center line L which is described above. In
more detail, for example, first, the control unit may align the
droplet camera 4 in the Z axis direction. The control unit may
perform alignment based on the captured image P, until the number
of the pixels of the positive direction side and the negative
direction side of the Z axis direction become the same by setting
the center line L as the boundary between positive side and
negative side pixels.
[0108] Accordingly, in the flow cytometer 1, the image P of the
fluid stream S (or the liquid droplets D) can be automatically
aligned and displayed in the center of the display.
[0109] 2-6. Orbital Direction Determining Step S.sub.6
[0110] In the step S.sub.6, the control unit may determine the
trajectory of the fluid stream S (or the liquid droplets D) (see
FIG. 4). In more detail, the control unit may determines a
deviation of the trajectory in the Z axis direction and also a
deviation of the trajectory in the X axis direction. Hereinafter,
the processes of "Z axis direction determining step S.sub.61" and
"X axis direction determining step S.sub.62" are included. Each
process will be described later.
[0111] 2-6-1. Z Axis Direction Determining Step S.sub.61
[0112] In the step S.sub.61, the control unit may determine a
trajectory of the fluid stream S (or the liquid droplets D) in the
Z axis direction.
[0113] As depicted in FIGS. 7A and 7B, the control unit may compare
the center line L and predetermined center line information stored
in the memory unit in advance. With respect to the fluid stream S
(or the liquid droplets D), the center line L is detected as
described above. The predetermined center line information may be
information representing a straight line perpendicular to XZ plane
stored in the memory unit in advance, and may further represent a
line which makes the number of pixels of the positive direction
side and the negative direction side of the Z axis direction the
same by setting the predetermined center line as the boundary, in
the captured image.
[0114] Herein, the comparison between the center line L and the
predetermined center line information I stored in the memory unit
in advance will be described while further referring to FIGS. 8A
and 8B, in addition to FIGS. 7A and 7B. FIGS. 8A and 8B also show
states where the determined center line L of the fluid stream S (or
the liquid droplets D) is detected in the captured image in the
same manner as FIGS. 7A and 7B.
[0115] In the example shown in FIG. 8A, the center line L is
deviated by .theta.1 degrees in the YZ plane with respect to the
predetermined center line information I (see FIG. 8A). In the same
manner, in the example shown in FIG. 8B, the center line is
deviated by .theta.2 degrees in the YZ plane when compared to the
predetermine center line information I (see FIG. 8B). In the
example shown in FIG. 8A, the process of the display step S.sub.5,
for making the number of the pixels of the positive direction side
and the negative direction side of the Z axis direction the same by
setting the center line L as the boundary by the control unit is
omitted.
[0116] Meanwhile, in a case of the example shown in FIGS. 7A and
7B, the control unit may determine that there is nearly no
deviation of the center line L in the YZ plane with respect to the
predetermined center line information I (see FIGS. 7A and 7B).
[0117] The control unit may also be configured to determine that an
inclination angle (e.g., the angles .theta.1, or .theta.2) with
respect to the center line information I of the center line L
detected based on the comparison of the center line L and the
center line information I, exceeds a predetermined threshold value,
and determine that the microchip is abnormal. As described above,
the control unit can determine the deviation of the trajectory of
the fluid stream S (or the liquid droplets D) in the Z axis
direction by comparing the center line information I and the center
line L, and when the trajectory is deviated, the control unit can
automatically determine that the microchip or the like is in a
malfunction state (abnormal state of clogging or the like). An
inclination angle that may result in an abnormal determination may
be an inclination angle greater than 0.5 degree in some
embodiments, greater than 1 degree in some embodiments, greater
than 2 degrees in some embodiments, greater than 5 degrees in some
embodiments, greater than 10 degrees in some embodiments, or
greater than 20 degrees in some embodiments. An abnormal
inclination angle may be an angle at which the ejected stream will
no longer be captured by a collection vessel.
[0118] 2-6-2. X Axis Direction Determining Step S.sub.62
[0119] In the step S.sub.62, the control unit may determine a
trajectory of the fluid stream S (or the liquid droplets D) in the
X axis direction (see FIG. 4).
[0120] FIGS. 9A and 9B show pictures of an example of the images of
the liquid droplets in which the focusing may be performed. As
shown in FIG. 9A, when the trajectory of the liquid droplets D is
not deviated in the X axis direction, since the focusing of the
droplet camera 4 is performed based on the signals of the control
unit, a focused region R1 is detected for the length of the stream
in the image, while a non-focused region R2 is not detected.
[0121] Meanwhile, as shown in FIG. 9B, when the trajectory of the
liquid droplets D is deviated in the X axis direction, since the
focusing of the droplet camera 4 is performed based on the signals
of the control unit, a focused region R1 is detected for a portion
of the stream length and a non-focused region R2 is also
detected.
[0122] Since the control unit detects both the non-focused region
R2 and the focused region R1 in the image P, the abnormity of the
microchip or the like can be determined. Accordingly, when
identifying the existence of the non-focused region R2 in the image
of the fluid stream S or the liquid droplets D and confirming the
existence of the non-focused region R2, the control unit determines
that the trajectory of the fluid stream S or the liquid droplets D
is deviated in the X axis direction. Therefore, in the flow
cytometer 1, when the trajectory is deviated in the X axis
direction, the control unit may automatically determine that the
microchip or the like is in a malfunction state (abnormity state of
clogging or the like).
[0123] FIGS. 10A and 10B show schematic diagrams of the image of
fluid stream S in which at least one bright point is detected. As
shown in FIGS. 10A and 10B, for example, the control unit may
perform focusing on a negative direction side of the Y axis
direction, and at least one bright point B may be detected (see
FIG. 10A). Further, the control unit may perform focusing on a
positive direction side of the Y axis direction, and at least one
bright point B may be detected at a second focus position different
from a first focus position found for the at least one bright point
B shown in FIG. 10A (see FIG. 10B). Accordingly, the control unit
can perform the focusing on two portions of the end portions (end
portion of the positive Y axis direction side and the end portion
of the negative Y direction side) of the fluid stream S in the
image P of the fluid stream S. Thus, the control unit can obtain
position information corresponding to the deviation of the
trajectory in the X axis direction, and in the collection tube
moving and aligning step S.sub.8 which will be described later, the
aligning of the collection tubes 3 in the X axis direction can be
performed by using the detected position information.
[0124] 2-7. Alerting Step S.sub.7
[0125] In the step S.sub.7, after evaluating stream or droplet
trajectories in the Z axis direction and/or the X axis direction,
the control unit may determine that the inclination or deviation
angle exceeds a predetermined threshold value. In response, the
control unit may perform alerting with respect to a user (see FIG.
4). In this case, various methods such as, a method for displaying
a light or a message by a display unit such as a display, or a
method for providing an output unit in the flow cytometer 1 and
alerting by an audio output or the like, can be used as a method
for alerting a user. Thus, the user can check for the, malfunction,
breakage, or the like of the chip.
[0126] 2-8. Collection Tube Moving and Aligning Step S.sub.8
[0127] In the collection tube moving and aligning step S.sub.8, the
control unit may perform positioning of the collection tubes 3
based on the position information corresponding to the deviation of
the trajectory in the X axis direction described above (see FIG.
4). In detail, the information regarding the trajectory of the
fluid stream S (or the liquid droplets D) in the X axis direction
is converted into the position information of the collection tubes
3 in the same direction, and the collection tubes 3 are moved to
the position corresponding to the converted position information.
Accordingly, the collection tubes 3 disposed in the collection tube
container 31 and the fluid stream S are aligned in the X axis
direction, and it is possible for the ejected fluid stream S to
reach the collection tubes 3 precisely.
In addition, in the collection tube moving and aligning step
S.sub.8, the control unit may perform positioning of the collection
tube container 31 based on the position information obtained by the
aligning of the Z axis direction described above. In detail, the
information regarding the trajectory of the fluid stream S (or the
liquid droplets D) in the Z axis direction is converted into the
position information of the collection tubes 3 in the same
direction, and the Z axis stage 32 is moved to the position
corresponding to the converted position information. Thus, the
collection tubes 3 disposed in the collection tube container 31 and
the fluid stream S are aligned in the Z axis direction, and it is
possible for the ejected fluid stream S to reach the collection
tubes 3 precisely. In the above descriptions, each process of the
steps S.sub.1 to S.sub.8 has been described in order, however, the
present technology is not limited to be executed in this order. For
example, the process of step S.sub.7 may be executed after the
process of the step S.sub.8. In some embodiments, not all steps may
be implemented. In some embodiments, one or more steps may be
repeated.
3. Various Additional Embodiments
[0128] Additional embodiments of apparatus and related methods are
also contemplated. In some embodiments, a micro-particle sorting
apparatus comprises an imaging device that images a fluid stream
ejected from an orifice, or liquid droplets discharged from the
orifice, and a control unit. The control unit may be configured to
detects a center line of the fluid stream or the plurality of the
liquid droplets from contrasted points in an image of the fluid
stream or the liquid droplets imaged by the imaging device, and
compare the center line with preset center line information. The
micro-particle sorting apparatus may further include a display unit
that displays the image. According to some embodiments, the imaging
device may be configured to focus the captured image, and the
control unit may performs focusing on at least a part of regions of
the image. The control unit may be configured to determine, based
upon a contrast ratio of selected portion of the image falling in a
predetermined range, that the image is in a focused state or a
non-focused state. According to some embodiments, the
micro-particle sorting apparatus may comprise a microchip flow
cytometer in which the orifice is provided in a microchip.
[0129] In some embodiments, the control unit may be configured to
identify or set a straight line corresponding to a plurality of the
contrasted points of the fluid stream displayed along the ejection
direction in the image of the fluid stream imaged by the imaging
device. The straight line may be identified as the center line and
trajectory of the ejected fluid stream from the orifice. In some
embodiments, the control unit may be configured to identify or set
the straight line corresponding to a plurality of the contrasted
points of the liquid droplets displayed along the ejection
direction discharged from the orifice in the image of the fluid
stream imaged by the imaging device, and to identify the straight
line as a center line and trajectory of the ejected droplets. The
control unit may be configured to determine an abnormity of the
ejected fluid stream or liquid droplets by calculating an
inclination value between the identified center line and a
predetermined reference line. The abnormality may be determined
when a comparison between the center line and the reference line
exceeds a predetermined threshold value.
[0130] In some embodiments of the micro-particle sorting apparatus,
the control unit may be configured to determine an existence of a
non-focused region in the image of the fluid stream or the
plurality of the liquid droplets. The control unit may determine an
abnormity in the image when the non-focused region and a focused
region are detected in the image of the fluid stream or the
plurality of the liquid droplets.
[0131] According to some embodiments, the micro-particle sorting
apparatus may comprise a pair of deflection plates that are
disposed to oppose each other with the fluid stream or the liquid
droplets imaged by the imaging device interposed therebetween. The
micro-particle sorting apparatus may further comprise at least one
collection container configured to collect the fluid stream and
capable of moving at least in a direction parallel to the imaging
direction of the imaging device. The control unit may be configured
to adjust the position of the collection container based on
information regarding a deviation of the orbital direction of the
fluid stream obtained by focusing on at least two parts in the
image of the fluid stream. The focusing of the two parts may
comprise a focusing of two end portions of the fluid stream in the
image of the fluid stream.
[0132] In some embodiments, the control unit may be configured to
determine the diameter of the orifice based on the width of the
fluid stream detected in the perpendicular direction to the
trajectory direction of the fluid stream of the image imaged by the
imaging device.
[0133] The foregoing embodiments and features of a micro-particle
sorting apparatus may be implemented in any combination.
[0134] Embodiments also include a method of determining a
trajectory of a fluid stream or liquid droplets of a micro-particle
sorting apparatus. The method may comprise, in order, acts of
obtaining an image of an ejected fluid stream or liquid droplets,
detecting a center line from contrasted points within the image,
comparing the center line with preset reference line information,
and displaying the image. The contrasted points may be located
centrally within the ejected fluid stream or liquid droplets.
[0135] As described above, in the flow cytometer 1, the trajectory
of the fluid stream S (or the liquid droplets) can be automatically
determined. Thus, in the flow cytometer 1, highly precise analysis
can be simply performed.
[0136] The present technology contains subject matter related to
that disclosed in Japanese Priority Patent Application JP
2012-080366 filed in the Japan Patent Office on Mar. 30, 2012, the
entire contents of which are hereby incorporated by reference.
[0137] It should be understood by those skilled in the art that
various modifications, combinations, sub-combinations and
alterations may occur depending on design requirements and other
factors insofar as they are within the scope of the appended claims
or the equivalents thereof.
* * * * *