US 6,859,659 B1Granted

Estimation of vector velocity

AssigneeB-K Medical A/S

InventorJørgen Arendt Jensen

Life of this patent

Estimating the term…

Abstract

A method and apparatus are provided for estimating the velocity vector of a remotely sensed object or group of objects using either ultrasound or electromagnetic radiation. The movement of the object is determined by emitting and receiving a pulsed field with spatial oscillations in both the axial and transverse directions. Using a number of pulsed emissions and the transverse spatial oscillations the received signal is influenced by transverse motion and a new autocorrelation estimator is used for determining the velocity vector.

Claims11

Dependent claims

An apparatus for measuring the velocity of a moving object or a collection of moving objects, the apparatus comprising:

a generator for generating pulses of excitation signals, an emitting transducer for transforming said excitation signals into a beam of wave energy and for emitting said wave energy in a predetermined direction of propagation, a receiving transducer for receiving signals from said moving object or objects generated by interaction with said wave energy emitted from said emitting transducer, wherein said emitting transducer and said receiving transducer having respective sensitivities which in combination give a resulting sensitivity oscillating spatially in a direction transverse to said direction of propagation, wherein the velocity component transverse to the beam is estimated using
v
x
=
d
x
2
⁢
π
⁢
⁢
k2T
prf
⁢
arctan
⁡
(
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
+
𝒥
⁢
{
R
2
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
1
⁡
(
k
)
}
ℛ
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
-
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
𝒥
⁢
{
R
2
⁡
(
k
)
}
)
(
36
)
as an estimator,
and the axial velocity component along the beam is estimated using
v
z
=
c
2
⁢
π
⁢
⁢
k4T
prf
⁢
f
0
⁢
arctan
⁡
(
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
-
𝒥
⁢
{
R
2
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
1
⁡
(
k
)
}
ℛ
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
+
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
𝒥
⁢
{
R
2
⁡
(
k
)
}
)
(
37
)
as an estimator,
where ℑ{R(k)} denotes the imaginary part of the complex autocorrelation and ℑ{R(k)} the real part, and where R1(k) is the complex lag k autocorrelation value for the signal r1(i) given by
r1(i)=rsq(i)+jrsqh(i) (38)
where rsq(i) is the received and sampled spatial quadrature field and rsqh(i) is the spatial Hilbert transform of rsq(i) and R2(1) is the complex lag one autocorrelation value for the signal r2(i) given by
r2(i)=rsq(i)−jrsqh(i), (39)
where i denotes the pulse-echo line number, c is the speed of the wave energy, f0 is the center frequency of the emitted wave energy, dx is a period of the lateral oscillation of the sensitivity, and Tprf is the time between pulse emissions.

220 more elements

A method of estimating the velocity of a moving object or a collection of moving objects, the method comprising

emitting an excitation signal of pulses of wave energy as a beam in a predetermined direction of propagation, whereby at least part of the wave energy will interact with the moving object or collection of moving objects, receiving, from said moving object or objects, reflected signals resulting from interaction of emitted wave energy with the moving object or collection of moving objects, wherein the emission of the excitation signal and the reception of reflected signals have respective sensitivities which in combination give a resulting sensitivity oscillating spatially in a direction transverse to the direction of propagation, estimating the velocity component transverse to the predetermined direction, using
v
x
=
d
x
2
⁢
π
⁢
⁢
k2T
prf
⁢
arctan
⁡
(
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
+
𝒥
⁢
{
R
2
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
1
⁡
(
k
)
}
ℛ
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
-
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
𝒥
⁢
{
R
2
⁡
(
k
)
}
)
(
36
)
as an estimator, and
estimating the axial velocity component along the predetermined direction using
v
z
=
c
2
⁢
π
⁢
⁢
k4T
prf
⁢
f
0
⁢
arctan
⁡
(
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
-
𝒥
⁢
{
R
2
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
1
⁡
(
k
)
}
ℛ
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
+
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
𝒥
⁢
{
R
2
⁡
(
k
)
}
)
(
37
)
as an estimator,
where ℑ{R(k)} denotes the imaginary part of the complex autocorrelation and {R(k)} the real part, and where R1(k) is the complex lag k autocorrelation value for the signal r1(i) given by
r1(i)=rsq(l)+jrsqh(i) (38)
where rsq(i) is the received and sampled spatial quadrature field and rsqh(i) is the spatial Hilbert transform of rsq(i) and R2(1) is the complex lag one autocorrelation value for the signal r2(i) given by
r2(i)=rsq(i)−jrsqh(i), (39)
where i denotes the pulse-echo line number, c is the speed of the wave energy, f0 is the center frequency of the emitted wave energy, dx is a period of the lateral oscillation of the sensitivity, and Tprf is the time between pulse emissions.

220 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/959,883Filed 10 May 2000
Priority: DK 1999 0063310 May 1999
Granted: 22 Feb 2005
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

G01S 15/8984
Combined Doppler and pulse-echo imaging systems: measuring the velocity vector
G01P 5/22
By measuring the time taken to traverse a fixed distance: using auto-correlation or cross-correlation detection means
G01P 5/244
By using reflection of acoustical waves, i.e. Doppler-effect: involving pulsed waves
G01P 13/02
Indicating or recording presence, absence, or direction, of movement: indicating direction only, e.g. by weather vane

Family

No related US applications are recorded in the indexed filing history.

Timeline

Citations

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Abstract

An apparatus for measuring the velocity of a moving object or a collection of moving objects, the apparatus comprising:

a generator for generating pulses of excitation signals, an emitting transducer for transforming said excitation signals into a beam of wave energy and for emitting said wave energy in a predetermined direction of propagation, a receiving transducer for receiving signals from said moving object or objects generated by interaction with said wave energy emitted from said emitting transducer, wherein said emitting transducer and said receiving transducer having respective sensitivities which in combination give a resulting sensitivity oscillating spatially in a direction transverse to said direction of propagation, wherein the velocity component transverse to the beam is estimated using
v
x
=
d
x
2
⁢
π
⁢
⁢
k2T
prf
⁢
arctan
⁡
(
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
+
𝒥
⁢
{
R
2
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
1
⁡
(
k
)
}
ℛ
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
-
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
𝒥
⁢
{
R
2
⁡
(
k
)
}
)
(
36
)
as an estimator,
and the axial velocity component along the beam is estimated using
v
z
=
c
2
⁢
π
⁢
⁢
k4T
prf
⁢
f
0
⁢
arctan
⁡
(
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
-
𝒥
⁢
{
R
2
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
1
⁡
(
k
)
}
ℛ
⁢
{
R
1
⁡
(
k
)
}
⁢
ℛ
⁢
{
R
2
⁡
(
k
)
}
+
𝒥
⁢
{
R
1
⁡
(
k
)
}
⁢
𝒥
⁢
{
R
2
⁡
(
k
)
}
)
(
37
)
as an estimator,
where ℑ{R(k)} denotes the imaginary part of the complex autocorrelation and ℑ{R(k)} the real part, and where R1(k) is the complex lag k autocorrelation value for the signal r1(i) given by
r1(i)=rsq(i)+jrsqh(i) (38)
where rsq(i) is the received and sampled spatial quadrature field and rsqh(i) is the spatial Hilbert transform of rsq(i) and R2(1) is the complex lag one autocorrelation value for the signal r2(i) given by
r2(i)=rsq(i)−jrsqh(i), (39)
where i denotes the pulse-echo line number, c is the speed of the wave energy, f0 is the center frequency of the emitted wave energy, dx is a period of the lateral oscillation of the sensitivity, and Tprf is the time between pulse emissions.

220 more elements

Facts

Application

09/959,883Filed 10 May 2000

Priority

DK 1999 0063310 May 1999

Granted

22 Feb 2005

Term ends

Not estimatedThe source records don’t support an estimate.

Classification11 codes

G01S 15/8984
Combined Doppler and pulse-echo imaging systems: measuring the velocity vector
G01P 5/22
By measuring the time taken to traverse a fixed distance: using auto-correlation or cross-correlation detection means
G01P 5/244
By using reflection of acoustical waves, i.e. Doppler-effect: involving pulsed waves
G01P 13/02
Indicating or recording presence, absence, or direction, of movement: indicating direction only, e.g. by weather vane