US 8,998,813 B2Granted

Image forming apparatus and image forming method

AssigneeCanon Kabushiki Kaisha

InventorKatsumi Nakagawa

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Abstract

An image forming apparatus has acoustic transducers; and an image processing unit which calculates intensity of acoustic waves irradiated from regions inside a subject respectively by processing received signals, which are output from the acoustic transducers, by a Fourier-domain method. The image processing unit includes: a coefficient memory which stores coefficients computed in advance, the coefficient being a value determined only by a position of the acoustic transducer, position of the region and a time of receipt of the acoustic wave; a multiplier unit which multiplies the received signal of the acoustic transducer by the corresponding coefficient; and a voxel memory which accumulates multiplication results of the multiplier unit for each region.

Claims11

Dependent claims

An image forming apparatus for creating image data from information on an interior of a subject based on acoustic waves irradiated from the interior of the subject, comprising:

a plurality of acoustic transducers which receive acoustic waves and convert the acoustic waves into received signals;
and
an image processing unit which obtains intensity of acoustic waves irradiated from a plurality of regions inside the subject respectively by processing the received signals, which are output from said plurality of acoustic transducers, wherein said image processing unit includes:
a coefficient memory which stores coefficients determined by a position of a corresponding acoustic transducer, a position of a region a time of receipt of the acoustic wave, and variables of a Fourier transform having wave number dimensions;
a multiplier unit which obtains a coefficient corresponding to the acoustic transducer from said coefficient memory, and multiplies a received signal which is output from the acoustic transducer by the coefficient, for each acoustic transducer;
and
a voxel memory which accumulates multiplication results of said multiplier unit for each region,
wherein a coefficient A is obtained by a following formula, when (xi,yi) represents a position of the acoustic transducer i, (xj,yj,zj) represents a position of a region j in the subject, and t* represents a time of receipt of the acoustic wave:
A
⁡
(
x
j
,
y
j
,
z
j
⁢
:
⁢
⁢
x
i
,
y
i
,
t
*
)
=
1
(
2
⁢
π
)
3
⁢
∫
∫
∫
-
∞
∞
⁢
2
⁢
w
⁢
⁢
sgn
⁡
(
w
)
u
2
+
v
2
+
w
2
⁢
exp
⁢
{
ⅈ
⁡
[
u
⁢
(
x
i
-
x
j
)
+
v
⁡
(
y
i
-
y
j
)
-
wz
j
+
sgn
⁡
(
w
)
⁢
u
2
+
v
2
+
w
2
⁢
t
*
]
}
⁢
ⅆ
u
⁢
ⅆ
v
⁢
ⅆ
w
[
Expression
⁢
⁢
1
]
where u, v and w are variables of a Fourier transform, and sgn(w) is a function which is 1 when w>0, is 0 when w=0, and is −1 when w<0.

128 more elements

Dependencies are inferred from the claim text.

Facts

Application: 13/496,760Filed 9 Nov 2010
Priority: JP 2009-26189817 Nov 2009
Published: US 2012/0179041 A112 Jul 2012
Granted: 7 Apr 2015
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

A61B 5/0095
Detecting, measuring or recording by applying one single type of energy and measuring its conversion into another type of energy: by applying…
A61B 5/0073
Using light, e.g. diagnosis by transillumination, diascopy, fluorescence: by tomography, i.e. reconstruction of 3D images from 2D projections
A61B 5/7257
Characterised by using transforms: using Fourier transforms
A61B 8/00
Diagnosis using ultrasonic, sonic or infrasonic waves

Family

US 2012/0179041 A1Pre-grant publication · published 12 Jul 2012
US 8,998,813 B2This patent

From the US filing history. Foreign family members aren’t listed.

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