US 12,468,059 B2Granted

Method of measuring by electrical impedance tomography

AssigneeCommissariat A L'energie Atomique Et Aux Energies Alternatives

InventorsMathieu Darnajou, Guillaume Ricciardi

Life of this patent

Estimating the term…

Abstract

An electrical impedance tomography method for the measurement of a body comprising a cylindrical part containing a fluid, the method comprising arranging a number of electrodes around a periphery of the cylindrical part of the body, simultaneously exciting each of the electrodes, each electrode being excited by a potential of a selected form, measuring the electrical properties of the body using electrodes, and processing the data from measuring step so as to obtain a signed data matrix representative of an image.

Claims7

Dependent claims

An electrical-impedance-tomography measuring method of a body comprising a cylindrical portion containing a fluid, the method comprising:

arranging a number ne of electrodes around a periphery of the cylindrical portion of the body,
simultaneously exciting each of the ne electrodes, each electrode being excited by a potential Vnexc having a form:
V
n
exc
(
t
)
=
A
⁢
∑
m
=
1
n
e
cos
(
2
⁢
π
⁢
f
m
⁢
t
)
[
δ
m
cos
𝕆
(
m
⁢
θ
n
)
+
δ
m
sin
𝔼
(
m
⁢
θ
n
2
)
]
where A is a signal amplitude, θn is an angular position of electrode n, fm=m*f0 is an oscillation frequency, f0 is a fundamental frequency chosen such that fm is less than a Nyquist frequency of the system for all m, δ is the Kronecker delta, and
={2k+1:k∈} is the set of odd integers
={2k:k∈*} is the set of non-zero even integers,
measuring electrical properties Vnmeas of the body using the electrodes, and
processing data generated in the measuring step, by:
a) for each electrode En, computing data points Mn defined by:
M
n
(
k
)
=
1
RP
⁢
❘
"\[LeftBracketingBar]"
∑
p
=
0
P
-
1
V
n
meas
(
p
)
⁢
e
ik
⁢
β
p
❘
"\[RightBracketingBar]"
where R is a resistance of a resistor used to measure Vnmeas with Vnmeas=R In across terminals of the resistor, P is a number of points in a discrete sequence of measurement of the current In, p is a discrete time, k is a Fourier coefficient comprised between 1 and (ne−1) and βp=(2πp/P),
b) constructing a data matrix D from the data points Mn(k) for all n and for all k, according to the equation:
D
=
(
{
M
n
(
1
)
}
{
M
n
(
2
)
}
{
M
n
(
3
)
}
⋮
{
M
n
(
n
e
-
1
)
}
)
[
[
.
]
]
,
and
c) constructing a signed data matrix, the elements of which are defined by the following equation when a phase shift Φn,l(k) between an excitation potential at electrode 1 and a current measured at electrode n is less than π/2:
D
~
n
m
=
sin
⁡
(
Φ
n
,
l
(
k
)
)
❘
"\[LeftBracketingBar]"
sin
⁡
(
Φ
n
,
l
(
k
)
)
❘
"\[RightBracketingBar]"
⁢
D
n
m
[
[
.
]
]
and the elements of which are defined by the following equation when the phase shift Φn,l(k) between the excitation potential at electrode 1 and the current measured at electrode n is greater than or equal to π/2:
{tilde over (D)}nm=ΣnmDnm
where Σ is a sign matrix defined such that an i-th element of a j-th row of Σ is the sign of cosine ([2π/([j 1]/2)]*(i−1)/ne) for odd j and a sign of sine ([2π/(j/2)]*(i−1)/ne) for even j.

176 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/551,338Filed 25 Mar 2022
Priority: FR 210309926 Mar 2021
Published: US 2024/0184010 A16 Jun 2024
Granted: 11 Nov 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01N 27/026
By investigating impedance: dielectric impedance spectroscopy
G01V 3/06
Operating with propagation of electric current: using AC
G01V 3/02
Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation: operating with…
G01N
Investigating or analysing materials by determining their chemical or physical properties

Family

US 2024/0184010 A1Pre-grant publication · published 6 Jun 2024
US 12,468,059 B2This patent

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

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Abstract

An electrical-impedance-tomography measuring method of a body comprising a cylindrical portion containing a fluid, the method comprising:

arranging a number ne of electrodes around a periphery of the cylindrical portion of the body,
simultaneously exciting each of the ne electrodes, each electrode being excited by a potential Vnexc having a form:
V
n
exc
(
t
)
=
A
⁢
∑
m
=
1
n
e
cos
(
2
⁢
π
⁢
f
m
⁢
t
)
[
δ
m
cos
𝕆
(
m
⁢
θ
n
)
+
δ
m
sin
𝔼
(
m
⁢
θ
n
2
)
]
where A is a signal amplitude, θn is an angular position of electrode n, fm=m*f0 is an oscillation frequency, f0 is a fundamental frequency chosen such that fm is less than a Nyquist frequency of the system for all m, δ is the Kronecker delta, and
={2k+1:k∈} is the set of odd integers
={2k:k∈*} is the set of non-zero even integers,
measuring electrical properties Vnmeas of the body using the electrodes, and
processing data generated in the measuring step, by:
a) for each electrode En, computing data points Mn defined by:
M
n
(
k
)
=
1
RP
⁢
❘
"\[LeftBracketingBar]"
∑
p
=
0
P
-
1
V
n
meas
(
p
)
⁢
e
ik
⁢
β
p
❘
"\[RightBracketingBar]"
where R is a resistance of a resistor used to measure Vnmeas with Vnmeas=R In across terminals of the resistor, P is a number of points in a discrete sequence of measurement of the current In, p is a discrete time, k is a Fourier coefficient comprised between 1 and (ne−1) and βp=(2πp/P),
b) constructing a data matrix D from the data points Mn(k) for all n and for all k, according to the equation:
D
=
(
{
M
n
(
1
)
}
{
M
n
(
2
)
}
{
M
n
(
3
)
}
⋮
{
M
n
(
n
e
-
1
)
}
)
[
[
.
]
]
,
and
c) constructing a signed data matrix, the elements of which are defined by the following equation when a phase shift Φn,l(k) between an excitation potential at electrode 1 and a current measured at electrode n is less than π/2:
D
~
n
m
=
sin
⁡
(
Φ
n
,
l
(
k
)
)
❘
"\[LeftBracketingBar]"
sin
⁡
(
Φ
n
,
l
(
k
)
)
❘
"\[RightBracketingBar]"
⁢
D
n
m
[
[
.
]
]
and the elements of which are defined by the following equation when the phase shift Φn,l(k) between the excitation potential at electrode 1 and the current measured at electrode n is greater than or equal to π/2:
{tilde over (D)}nm=ΣnmDnm
where Σ is a sign matrix defined such that an i-th element of a j-th row of Σ is the sign of cosine ([2π/([j 1]/2)]*(i−1)/ne) for odd j and a sign of sine ([2π/(j/2)]*(i−1)/ne) for even j.

176 more elements

Facts

Application

18/551,338Filed 25 Mar 2022

Priority

FR 210309926 Mar 2021

Published

US 2024/0184010 A16 Jun 2024

Granted

11 Nov 2025

Term ends

Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01N 27/026
By investigating impedance: dielectric impedance spectroscopy
G01V 3/06
Operating with propagation of electric current: using AC
G01V 3/02
Electric or magnetic prospecting or detecting; Measuring magnetic field characteristics of the earth, e.g. declination, deviation: operating with…
G01N
Investigating or analysing materials by determining their chemical or physical properties