US 2021/0356573 A1Published application

Two dimension and three dimension imaging based on speed changes of sound/ultrasound

AssigneesHai Huang, Tony Huang

InventorsHai Huang, Tony Huang

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Abstract

The invention is based on speed changes of sound/ultrasound pulses and a fixed detecting depth between a transducer and sampling points to collect information of the detecting depth and/or a velocity of motionless and/or moving objects from the sampling points to construct two-dimension or three-dimension images of the sampling points. By taking advantages of a pulse ultrasound and a continuous ultrasound, a method of coded sound pulses can simultaneously collect the information of the detecting depth and the velocity from the sampling points, which improves imaging quality. Calculating a speed of the moving objects by simultaneously detecting time-of-flight (TOF) and TOF shift at same site from two separated piezoelectric (PZT) elements improves testing results with accuracy, simplification and reproducibility. An aliasing can be rectified based on the TOF and the TOF shift.

Claims18

Dependent claims

A method for correctly registering a position of sampling points on a sound imaging system by calculating a detecting depth based on a speed reduction of sound pulses during a transmission, the method comprising:

establishing a sound imaging system containing piezoelectric (PZT) elements within a transducer, wherein the PZT elements send emitted sound pulses and receive reflected sound pulses from the sampling points to calculate time-of-flight (TOF);
and
establishing a speed reducing coefficient (Coef) of the sound pulses in a transmitting medium, wherein the Coef contains various speed affecting factors for the sound pulses, including a density of the transmitting medium, a density and a thickness of the PZT elements, and a constant value (k), which comprising:
and
coef
=
k
×
medium
⁢
⁢
density
PZT
⁢
⁢
density
×
PZT
⁢
⁢
thickness
calculating an emitted time (TOFa) of the sound pulses emitted from the PZT elements to the sampling points, wherein the emitted time from the PZT elements to the sampling points is less than a reflected time from the sampling points back to the PZT elements due to the speed reduction during the transmission;
and
TOFa
=
TOF
⁡
(
1
-
Coef
)
2
-
Coef
obtaining an average speed (Vavg) of the emitted sound pulses during the TOFa based on a maximal speed (Vm) of the sound pulses, the Coef and the TOFa;
the Vm is a maximal speed of the sound pulses as just entering the transmitting medium from the PZT elements, wherein the Vavg is variable due to different detecting depths of the sampling points, which will compensate an effect of the speed reduction on calculating the detecting depth, which comprising:
Vavg=Vm×(1−Coef×TOFa);
and
Calculating the detecting depth of the sampling points, wherein the detecting depth is based on the Vavg and the TOFa, which is more accurate than a compromised detecting depth of the sampling points calculated based on an identical speed of the sound pulses and the TOF;
and
Detecting depth=Vavg×TOFa
Correctly registering the position of the sampling points on the sound imaging system, wherein the compromised detecting depth of the sampling points based on the identical speed of the sound pulses is rectified, which improves imaging quality.

40 more elements

A method of establishing the sound image for a continuous, a pulsed and a color ultrasound by calculating a velocity of moving objects based on speed changes of the sound pulses, which comprising:

constructing the sound imaging system containing the PZT elements within the transducer to send the emitted sound pulses and receive the reflected sound pulses from the sampling points;
and
obtaining a TOF shift from the sound pulses reflected from different moving objects that pass the sampling points to calculate the velocity of the moving objects;
and
constructing the sound image or the profile of the velocity of the moving objects from the sampling points.

2 more elements

A method of using coded sound pulses to simultaneously obtain the detecting depth and the velocity from the sampling points with motionless/moving objects, which comprising:

the transducer containing one pair or more of emitting PZT elements and receiving PZT elements, wherein different numbers of the sound pulses within each pulse duration is assigned to form different pulse characters, a resting period is a time between each adjacent pulse duration;
and
forming an emitted code of the pulse characters, wherein the emitting PZT elements send the coded sound pulses to form the emitted code of the pulse character, which endows each pulse character with an emitted time, and an emitted resting period keeps identical;
and
obtaining the TOF and the TOF shift, wherein the receiving PZT elements receive reflected coded sound pulses and the sound imaging system decodes the reflected coded sound pulses to form a received code of the pulse characters, which is compares with the emitted code of the pulse characters;
then the TOF is obtained from a time between the emitted code of the pulse characters and the correspondingly received code of the pulse characters, and the TOF shift is obtained from a time difference between the emitted resting period and the correspondingly received resting period;
and
identifying the sampling points with the motionless objects, wherein the TOF is identical and the TOF shift is zero from the sampling points with the motionless objects;
and then the detecting depth of the sampling points with the motionless objects is calculated from the TOF;
and
identifying the sampling points with the moving objects, wherein variable values of the TOF and the TOF shift are obtained from the sampling points with the moving objects;
the velocity of the moving objects from the sampling points is calculated with the Rt equation, the detecting depth of the sampling points is calculated based on a sum of the TOF and the TOF shift with the average speed of the sound pulses in the transmitting medium;
for the sampling points with the forward moving objects, the TOF shift is positive, which compensates shortened TOF;
and for the sampling points with the reversely moving objects, the TOF shift is negative, which offsets elongated TOF;
Rco is a ratio of the TOF shift with the emitted resting period;
the detecting depth and the velocity of the moving objects at the sampling points can be calculated as following:
TOF
⁢
⁢
shift
=
emitted
⁢
⁢
resting
⁢
⁢
period
-
received
⁢
⁢
resting
⁢
⁢
period
Rco
=
TOF
⁢
⁢
shift
emitted
⁢
⁢
resting
⁢
⁢
period
Rc
=
2
×
V
objects
V
avg
sum
⁢
⁢
of
⁢
⁢
TOF
=
TOF
+
TOF
⁢
⁢
shift
TOFa
=
sum
⁢
⁢
of
⁢
⁢
TOF
×
(
1
-
Coef
)
2
-
Coef
Detecting
⁢
⁢
depth
=
V
avg
×
TOFa

95 more elements

Dependencies are inferred from the claim text.

Facts

Application: 17/388,175Filed 29 Jul 2021
Priority: 12 Mar 2015
Published: 18 Nov 2021
Term ends: Not estimatedThe source records don’t support an estimate.

Classification5 codes

G01S 7/523
Of systems according to group G01S15/00: details of pulse systems
G01S 15/02
Systems using the reflection or reradiation of acoustic waves, e.g. sonar systems: using reflection of acoustic waves
G01S 15/58
Systems of measurement, based on relative movement of the target: velocity or trajectory determination systems; Sense-of-movement determination…
G01S 15/8986
Combined Doppler and pulse-echo imaging systems: with measures taken for suppressing velocity ambiguities, i.e. anti-aliasing

Family

Application14/645,475Continuation · filed 12 Mar 2015
Application15/613,308Continuation · filed 5 Jun 2017
Application17/388,175Continuation
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From the US filing history. Foreign family members aren’t listed.