PARALLEL EXCITATION SYSTEM CAPABLE OF SPATIAL ENCODING AND METHOD THEREOF

SYSTEME D'EXCITATION PARALLELE PERMETTANT DE PROCEDER A UN CODAGE SPATIAL ET PROCEDE ASSOCIE

English Abstract

A parallel excitation system based on spatial encoding technique
and a method thereof are provided. The system includes a parallel
excitation array consisting of a plurality of single-point excitation light
sources (11) and a spatial encoding control system (2). The spatial
encoding control system (2) includes a microcontroller (21), a driving
module (22), a switch control module (23), an output light power control
module (24) and an excitation time control module (25). The switch control
module (23) is used for the control of each single-point excitation light
source (11) to be turned on or off. The output light power of each single-
point
excitation light source (11) is controlled by the output light power
control module (24). The operating time of each single-point excitation
light source (11) is controlled by the excitation time control module (25).
The working parameters, such as the on or off, the output light power and
the operation time of the single-point excitation light sources, are
determined by the switch control module (23), the output light power
control module (24) and the excitation time control module (25). The
operating status of each single-point excitation light source (11) in the
parallel excitation array is set by the microcontroller (21) with the driving
module (22) according to corresponding parameters, and therefore spatial
encoding for the parallel excitation array is achieved with the spatial

encoding control system (2). The invention has wide applications with the
advantages of flexibility, high efficiency, convenience, and high spatial
resolution.

French Abstract

La présente invention a trait à un système d'excitation parallèle permettant de procéder à un codage spatial et à un procédé associé. Le système comprend un réseau d'excitation parallèle constitué d'une pluralité de sources lumineuses d'excitation à point unique (11) et d'un système de commande de codage spatial (2). Le système de commande de codage spatial (2) comprend un microcontrôleur (21), un module d'entraînement (22), un module de commande de commutation (23), un module de commande de puissance de lumière de sortie (24) et un module de commande de temps d'excitation (25). Le module de commande de commutation (23) est utilisé pour commander chaque source lumineuse d'excitation à point unique (11) afin qu'elle s'allume ou qu'elle s'éteigne. La puissance de lumière de sortie de chaque source lumineuse d'excitation à point unique (11) est commandée par le module de commande de puissance de lumière de sortie (24). Le temps de travail de chaque source lumineuse d'excitation à point unique (11) est commandé par le module de commande de temps d'excitation (25). Les paramètres du microcontrôleur (21) sont définis par le module de commande de commutation (23), le module de commande de puissance de lumière de sortie (24) et le module de commande de temps d'excitation (25), et en fonction des paramètres définis correspondants, l'état de fonctionnement de la source lumineuse d'excitation à point unique (11) dans le réseau d'excitation parallèle est défini par le microcontrôleur (21) au moyen du module d'entraînement (22), ce qui permet au système de commande de codage spatial (2) de procéder à un codage spatial du réseau d'excitation parallèle. L'invention présente les avantages suivants : flexibilité, grande efficacité, commodité, importante résolution de l'espace et portée étendue en termes d'application.

Claims

WHAT IS CLAIMED IS:
1. A parallel excitation system based on spatial encoding technique,
characterized in that the system includes a parallel excitation array
consisting of a plurality of single-point excitation light sources and a
spatial
encoding control system including a microcontroller, a driving module, a
switch control module, an output light power control module and an
excitation time control module; wherein the switch control module controls
each single-point excitation light source to turn on or off; the output light
power control module controls the output light power of each single-point
excitation light source; the excitation time control module controls the
operating time of each single-point excitation light source, wherein
working parameters, such as the on or off, the output light power and the
operation time of the single-point excitation light sources, are determined
by the switch control module, the output light power control module and
the excitation time control module; a working status of each single-point
excitation light source in the parallel excitation array is controlled by the
driver module, wherein the microcontroller sends the appropriate
parameters that have been set before to the driver module, and therefore
achieves space coding of the parallel excitation array.
11

2. The parallel excitation system based on spatial encoding
technique according to claim 1, characterized in that the single-point
excitation light source is a high power LED or a laser diode.
3. The parallel excitation system based on spatial encoding
technique according to claim 1 or 2, characterized in that the parallel
excitation array is an array of rectangular, round, fan or other shapes.
4. A method of parallel excitation with spatial encoding based on
the system according to any of claims 1 to 3, including the steps of:
(1) Determining a parallel excitation mode according to specific
experiment conditions such as goals, objects and fluorescent markers of an
experiment;
(2) Setting the contents of the parallel excitation mode into the
spatial coding control system after the mode determined according to
specific experiment requirements, and then operating states of each single-
point excitation light source are set by these modules in the spatial coding
control system to achieve spatial encoding for the parallel excitation array;
(3) Performing fluorescence imaging under the excitation of the
spatially encoded parallel excitation array.
12

5. The method of parallel excitation based on spatial encoding
technique according to claim 4, characterized in that the contents of the
parallel excitation mode include the number and distribution of the single-
point excitation light sources, as well as the output light power, operating
time and excitation sequence of each single-point excitation light source,
and the parallel excitation mode specifically includes the following four
modes:
1 When the whole-body distribution of fluorescent markers needs
to be imaged, a plurality of single-point excitation light sources are
selected
and set to work simultaneously to perform excitation, wherein the number
of the single-point excitation light sources is determined by the volume of
the object, and the output light power and operating time of each single-
point excitation light source are determined by specific experimental
requirements;
2 When the distribution of fluorescent markers in a local region of
the experimental animal needs to be imaged, a single-point excitation light
source is selected to perform excitation according to where the region
locates, wherein the output light power and operating time of the single-
point excitation light source are determined by specific experiment
requirements;
3 When a migration process of the fluorescent marker in the
experimental animal needs to be tracked dynamically, a plurality of single-
13

point excitation light sources are selected and set to work sequentially to
perform excitation, with each single-point excitation light source being set
to be turned on when the fluorescent marker passing the single-point
excitation light source, wherein the output light power is determined by
specific experiment requirements;
4 Other parallel excitation modes such as point-by-point scanning
excitation, row-by-row(column-by-column) sequential excitation,
interlacing excitation in rows/columns, or alternate excitation in two
rows/columns) can be selected according to practical needs.
14

Description

CA 02782964 2012-06-05
PARALLEL EXCITATION SYSTEM CAPABLE OF SPATIAL
ENCODING AND METHOD THEREOF
Technical Field
The present invention relates to the technique of optical molecular
imaging, particularly to a parallel excitation system based on spatial
encoding technique and a method thereof used in fluorescence imaging.
Background Art
Fluorescence molecular imaging is a new molecular imaging
technique which developed rapidly in recent years. It has broad application
prospects in the fields of tumor detection, drug development, and disease
diagnosis. In fluorescence imaging, an external light with appropriate
wavelength is used to excite specific fluorophore labeled molecules or cells,
followed almost immediately by release of fluorescence. After scattering
and absorption in biological tissues, the fluorescence signals can be
detected by specific devices at the surface of the imaged object. The
internal distributions of fluorochromes or chromophores in tissues can be
obtained based on the fluorescence measurements. Normal or abnormal
biological processes can be visualized at molecular and cellular levels
spatially and temporally, with the advantages of high sensitive, non-
ionizing radiation, non-invasive, and low cost.

CA 02782964 2012-06-05
However, with the conventional single-point light source excitation
mode, only a limited volume of the imaged object near the excitation light
source can be excited and fluorescence signals only from a local region can
be acquired in fluorescence imaging. Fluorescent markers distributed in
other volumes far away from the excitation light source may not be excited
or only poorly excited. As a result, the obtained fluorescence information is
incomplete and incorrect. Although fluorescence information at different
regions can be obtained by successively changing the position of the single-
point excitation light source to collect multiple cycles of projections, the
complexity of the imaging system and the data acquisition time will be
increased. It is unacceptable in practical cases where fluorescent signals
with different temporal and spatial distributions need to be observed,
especially in the imaging of fast dynamic process.
Summary of the Invention
For the above issues, the present invention provides a parallel
excitation system based on spatial encoding technique used for
fluorescence imaging and method thereof.
In order to achieve above objective, the present invention employs
the following technical solution: a parallel excitation system based on
spatial encoding technique is characterized in that: the system includes a
parallel excitation array consisting of a plurality of single-point excitation
2

CA 02782964 2015-01-20
light sources and a spatial encoding control system; the spatial encoding
control system includes a microcontroller, a driving module, a switch
control module, an output light power control module and an excitation
time control module; wherein the switch control module controls each
single-point excitation light source to be turned on or off, the output light
power control module controls the output light power of each single-point
excitation light source; the excitation time control module controls the
operating time of each single-point excitation light source. The working
parameters, such as the on or off, the output light power and the operation
time of the single-point excitation light sources, are determined by the
switch control module, the output light power control module and the
excitation time control module. The working status of each single-point
excitation light source in the parallel excitation array is controlled by the
driver module. The microcontroller sends appropriate parameters that have
been determined before to the driver module, and therefore achieves space
encoding of the parallel excitation array.
The single-point excitation light source is a high power LED or a
laser diode.
The parallel excitation array may be an array in a rectangular, round,
fan shape or other shapes.
A method of parallel excitation with spatial encoding technique
based on above system, includes the steps of: (1) determining a parallel
3

CA 02782964 2015-01-20
excitation mode according to specific experiment conditions such as goals,
objects and fluorescent markers of an experiment; (2) setting the
determined parallel excitation mode into the spatial encoding control
system. Spatial encoding of the parallel excitation array is achieved by
controlling each single point excitation light source with the modules in the
spatial encoding control system; (3) performing fluorescence imaging with
the spatially encoded parallel excitation array.
The contents of the parallel excitation mode include the number and
distribution of the single-point excitation light source, as well as the
output
light power, operating time and excitation sequence of each single-point
excitation light source. It specifically includes the following four modes:
0 when the whole-body distribution of fluorescent markers needs to be
imaged, a plurality of single-point excitation light sources are selected and
set to work simultaneously to perform excitation, wherein the number of
the single-point excitation light source is determined by the volume of the
object, and the output light power and operating time of each single-point
excitation light source are determined by specific experiment requirements;
0 when the distribution of fluorescent markers in a local region of the
experimental animal needs to be imaged, a single-point excitation light
source is selected to perform excitation according to where the region
locates, wherein the output light power and operating time of the single-
4

CA 02782964 2012-06-05
point excitation light source are determined by specific experiment
requirements; when a migration process of the fluorescent marker in
the experimental animal needs to be tracked dynamically, a plurality of
single-point excitation light sources are selected and set to work
sequentially to perform excitation, with each single-point excitation light
source being set to be turned on when the fluorescent marker passing it,
wherein the output light power is determined by specific experiment
requirements; ,CD other parallel excitation modes such as point-by-point
scanning excitation, row-by-row(column-by-column) excitation, interlacing
excitation in rows/columns, or alternate excitation in two rows/columns)
can be selected according to practical needs.
Since the present invention employs the above technical solution, it
has following advantages compared to the prior art: the present invention
employs the spatial encoding based parallel excitation technique, which can
control the operation status of each single-point excitation light source in
the light source array according to practical needs. This technique can be
used to observe the temporal and spatial distribution of fluorescent markers
in the whole animal, to feature the distribution of fluorescent markers in
local regions specifically, and to track a migration process of a certain
fluorescent marker dynamically. Compared to the existing excitation mode
with a single-point light source, the method of parallel excitation based on

CA 02782964 2012-06-05
spatial encoding designed by the invention has wider applications with the
advantages of flexibility, high efficiency, convenience, short imaging time,
and high spatial resolution.
Brief Description of Figures
FIG. 1 shows a block diagram of the structure of the present
invention;
FIG. 2 shows a schematic view of the structure of a parallel
excitation array in the present invention.
DETAILED DESCRIPTION
The present invention will be described in detail with reference to
the embodiments of the present invention in conjunction with the
accompanying drawings.
As shown in FIG. 1, the system of the present invention includes a
parallel excitation array 1 and a spatial encoding control system 2.
As shown in FIG. 2, the parallel excitation array 1 includes a
plurality of single-point excitation light source 11 (labeled as Si, in FIG.2,
wherein i indicates the row where the single-point excitation light source
11 locates, and j indicates the column where the single-point excitation
6

CA 02782964 2012-06-05
light sources 11 locates). A plurality of single-point excitation light
sources
11 are arranged in a mxn array. in indicates the number of rows of the
array, and n indicates the number of columns of the array, with a spacing of
d1 between neighboring columns , and a spacing of d, between neighboring
rows. m, n, d1, and d2 are determined according to practical needs.
As shown in FIG. 1, the spatial encoding control system 2 includes a
microcontroller 21, a driving module 22, a switch control module 23, an
output light power control module 24, and an excitation time control
module 25. Wherein, the switch control module 23 controls each single-
point excitation light source 11 to turn on or off; the output light power
control module 24 controls the output light power of each single-point
excitation light source 11; the excitation time control module 25 controls
the operating time of each single-point excitation light source 11. The
working parameters, such as the on or off, the output light power and the
operation time of the single-point excitation light sources, are determined
by the switch control module 23, the output light power control module 24
and the excitation time control module 25. The working status of each
single-point light source 11 in the parallel excitation array 1 is controlled
by the driver module 22. The microcontroller 21 sends appropriate
parameters that have been determined before to the driver module 22, and
therefore achieves space encoding of the parallel excitation array 1.
In the above embodiment, the single-point excitation light source 11
7

CA 02782964 2015-01-20
can be a high power LED (light emitting diode) or a laser diode.
In the above embodiment, the plurality of single-point excitation
light source 11 may be arranged in an array of rectangular, round, fan or
other shapes.
The use of the parallel excitation system based on spatial coding
technique in fluorescence imaging includes the following steps:
(1) Determining a parallel excitation mode according to specific
experiment conditions such as goals, objects and fluorescent markers of an
experiment. The contents of the parallel excitation mode include the
number and distribution of the single-point excitation light sources 11, as
well as the output light power, operating time and excitation sequence of
each single-point excitation light source 11. It specifically includes the
following four modes:
When the whole-body distribution of fluorescent markers of an
experimental animal needs to be imaged, i x j single-point excitation light
sources 11 (Sõ S1, S¨ ) are selected and set to work simultaneously
to perform excitation, wherein the values of i and j are determined by the
volume of the object, and the output light power and operating time of each
single-point excitation light source 11 are determined by specific
experiment requirements;
When the distribution of fluorescent markers in a local region of
8

CA 02782964 2012-06-05
the experimental animal needs to be imaged, a single-point excitation light
sources S, is selected to perform excitation, wherein the values of i and j
are determined by the position of the region, and the output light power and
operating time of the single-point excitation light source 11 are determined
by specific experiment requirements;
0 When a migration process of the fluorescent marker in the
experimental animal needs to be tracked dynamically (assuming that a
migration path is SH -4 Si 2 - -> S22 ---> S32 Si ¨> S34), a
series of point
sõ 512 Sõ S32 S33
Sm are selected and set to work sequentially to
perform excitation, with each single-point excitation light source 11 being
set to be turned on when the fluorescent marker passing it, wherein the
output light power is determined by specific experiment requirements;
0 Other parallel excitation modes such as point-by-point scanning
excitation, row-by-row (column-by-column) excitation, interlacing
excitation in rows/columns, or alternate excitation in two rows/columns,
may be selected according to practical needs.
(2) Setting the determined parallel excitation mode into the spatial
coding control system 2. The operating state of each single-point excitation
light source 11 (including whether the single-point excitation light sources
11 is turned on, its output light power and operating time, as well as the
excitation order of the single-point excitation light sources 11) are set by
9

CA 02782964 2012-06-05
the modules in the spatial encoding control system 2 to achieve spatial
encoding of the parallel excitation array 1.
(3) Performing fluorescence imaging under the excitation of the
spatially encoded parallel excitation array 1.
(4) When the imaging process ends, new fluorescence imaging
experiment can be performed by adjusting the working mode of the parallel
excitation array 1 with the spatial encoding control system 2 according to
new experiment requirements.
While the present invention has been described with reference to the
above embodiment, the structure, position and connection of each part can
be changed. Based on the technical solution of the present invention, any
modifications and equivalent changes to a specific part according to the
principle of the present invention should not be excluded from the claimed
scope of the invention.

Representative Drawing