Control apparatus, measurement apparatus, control method, and storage medium

Patent metadata

Field	Value
Publication number	US-2016338592-A1
Application number	US-201615152759-A
Country	US
Kind code	A1
Filing date	May 12, 2016
Priority date	May 20, 2015
Publication date	Nov 24, 2016
Grant date	—

Abstract

A control apparatus includes a data acquiring unit configured to acquire a measured signal obtained by measuring light emitted from a test object onto which light is irradiated, a processing unit configured to calculate an objective function that varies in accordance with a statistical value obtained by statistically processing the measured signal, and a controller configured to control a modulation amount of a wavefront of the light irradiated onto the test object so as to minimize the objective function.

First claim

What is claimed is:

1 . A control apparatus comprising:
a data acquiring unit configured to acquire a measured signal obtained by measuring light emitted from a test object onto which light is irradiated; a processing unit configured to calculate an objective function that varies in accordance with a statistical value obtained by statistically processing the measured signal; and a controller configured to control a modulation amount of a wavefront of the light irradiated onto the test object so as to minimize the objective function.

2 . The control apparatus according to claim 1 , wherein the controller determines the modulation amount when the objective function is minimum, as a result of that the controller makes the data acquiring unit and the processing unit iteratively perform a processing by changing the modulation amount.

3 . The control apparatus according to claim 1 , wherein the modulation amount is at least one of a phase modulation amount and an amplitude modulation amount.

4 . The control apparatus according to claim 1 , wherein the controller sets a target area in the measured signal, and
wherein the processing unit calculates the objective function in the target area.

5 . The control apparatus according to claim 4 , wherein the test object contains an area in which an optical property changes with time, and
wherein the controller sets the area in which an optical property changes with time, to the target area.

6 . The control apparatus according to claim 1 , wherein the controller provides control so as to scan the test object with the light having a modulated wavefront.

7 . The control apparatus according to claim 1 , wherein the statistical value includes at least one of a standard deviation, a variance, and an average value of an intensity of the measured signal.

8 . The control apparatus according to claim 7 , wherein the objective function is a speckle contrast based on the standard deviation and the average value.

9 . The control apparatus according to claim 1 , wherein the statistical value is a temporal correlation of the measured signal.

10 . A measurement apparatus comprising:
a modulator configured to modulate a wavefront of light irradiated onto a test object; a measurement unit configured to measure light emitted from the test object and to output a measured signal; and a control apparatus configured to control the modulator and the measurement unit, wherein the control apparatus includes: a data acquiring unit configured to acquire the measured signal output from the measurement unit; a processing unit configured to calculate an objective function that varies in accordance with a statistical value obtained by statistically processing the measured signal; and a controller configured to control a modulation amount of the modulator for the wavefront of the light irradiated onto the test object so as to minimize the objective function.

11 . The measurement apparatus according to claim 10 , wherein the measurement unit includes an image capturing unit configured to capture an image of the test object, and
wherein the processing unit calculates a contrast value of the image obtained from the image capturing unit, and an objective function in which the contrast value and the contrast value are set as variables.

12 . The measurement apparatus according to claim 11 , wherein the objective function is larger when the contrast value has a first value than when the contrast value has a second value larger than the first value.

13 . The measurement apparatus according to claim 10 , wherein the test object contains an area in which an optical property changes with time, and the measurement unit obtains a change of the optical property with time by spatially and temporally performing a plurality of measurements.

14 . A control method comprising the steps of:
acquiring a measured signal obtained by measuring light emitted from a test object onto which light is irradiated; calculating an objective function that varies in accordance with a statistical value obtained by statistically processing the measured signal; and controlling a modulation amount of a wavefront of the light irradiated onto the test object so as to minimize the objective function.

15 . The control method according to claim 14 , wherein the controlling step determines the modulation amount when the objective function is minimum, as a result of that the controlling step makes the acquiring step and the processing step repetitively perform processing by changing the modulation amount.

16 . A non-transitory computer-readable storage medium for enabling a computer to execute a control method, wherein the control method includes the steps of:
acquiring a measured signal obtained by measuring light emitted from a test object onto which light is irradiated; calculating an objective function that varies in accordance with a statistical value obtained by statistically processing the measured signal; and controlling a modulation amount of a wavefront of the light irradiated onto the test object so as to minimize the objective function.

Assignees

• Canon Kk

Inventors

• Masumura Takahiro

Classifications

• G01N21/49

  within a body or fluid · CPC title

• A61B5/02007

  Evaluating blood vessel condition, e.g. elasticity, compliance · CPC title

• A61B5/0059 Primary

  using light, e.g. diagnosis by transillumination, diascopy, fluorescence (photoacoustic A61B5/0093; optical measurement of heart rate A61B5/02416; optical measurement of blood flow A61B5/0261; optical measurement of analytes A61B5/1455) · CPC title

• G01N2201/069

  Supply of sources · CPC title

• G01N21/4795 Primary

  spatially resolved investigating of object in scattering medium (in vivo A61B) · CPC title