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Description
Ultrasound imaging apparatus
The present invention relates to an ultrasound imaging
apparatus capable of displaying B-Mode and Doppler-mode
images. The invention specifically relates to an ultrasonic
imaging apparatus capable of tracking blocks in blood
vessels.
Ultrasonic imaging apparatuses are widely used in various
industrial fields. In particular, development of ultrasonic
imaging apparatuses as ultrasonic diagnostic apparatuses has
been significant in the medical field. In conventional
ultrasound imaging, the operator is required to manually
position an ultrasound transducer which transmits ultrasound
waves to the examination part of a subject to be diagnosed.
The transducer receives reflected ultrasonic waves from the
examination part of the subject. The transmitted and received
ultrasound signals are analyzed to produce B-Mode and
Doppler-mode images for diagnosis.
The processes using both B-Mode and Doppler-mode imaging is
time consuming and requires skill on the part of the
operator. During this period both the time of the operator as
well as the machine is blocked. In practice, it is often
difficult to keep the transducer on the exact place of
interest due to the movement of the probe in which the
transducers are located and/or the movement of the subject
under examination. Also in practice, it is still challenging
to obtain a good Doppler image for accurate positioning.
It is an object of the present invention to provide a more
accurate and fast automatic guidance system for tracking
blocks in blood vessels.
The above object is achieved by an ultrasonic imaging
apparatus, comprising:

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an ultrasound transducer that transmits a series of
ultrasound pulses into a subject under examination, and
receives echo signals in response to the series of
ultrasound pulses,
a Doppler-mode processing means that analyzes the echo
signals to produce a Doppler image,
a blood flow information output means, coupled to said
Doppler-mode processing means, for determining the blood
flow information in the blood vessel, and
a means adapted to provide indication of the trajectory
of the blood vessel corresponding to the blood flow
information.
The blood flow information output means coupled with the
Doppler-mode processor utilizes a phenomenon that an
ultrasonic pulse signal transmitted into a subject undergoes
a frequency deviation due to the Doppler Effect occurring
when the pulse signal is reflected by a moving object such as
a blood stream. And the apparatus is adapted to measure the
speed of the blood stream acting as a reflector by detecting
a Doppler deviated frequency. From these observations the
trajectory of the blood vessel having the block could be well
determined.
In a preferred embodiment of the invention, the Ultrasound
imaging apparatus comprises a B-Mode processing means that
analyzes the echo signals to produce a B-Mode image. This
facilitates the operator to position the transducer
accurately in the blood vessel where the block is suspected
and provides the operator the freedom to freeze the image and
take a screen shot at any point of time.
In a further preferred embodiment, the Ultrasound imaging
apparatus further comprises a switching means adapted to

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switch between the Doppler processing means and the B-Mode
processing means. The apparatus need to change from the B-
Mode to the Doppler-mode once the suspected blood vessel
having the block is detected for finding the blood flow
information. Also the apparatus need to change from the
Doppler-mode to the B-Mode once the position of the block is
detected. The switching means facilitates the automatic
switching of the modes allowing faster tracking and
detection.
In an alternative embodiment, the Ultrasound imaging
apparatus further comprises a display system adapted to
display the Doppler image and the B-Mode image. The display
system facilitates the operator to analyze the images
processed and displayed in both image modes.
In another alternative embodiment, the Ultrasound imaging
apparatus further comprises an indication means adapted to
generate an audio signal corresponding to a relative position
of a block and the series of ultrasound pulses. This
facilitates the operator to find the exact position of the
block much faster by interpreting the variations of the audio
signal.
In another alternative embodiment, the means adapted to
provide indication of the trajectory of the blood vessel is a
visual indication means associated with the ultrasound
transducer. The operator can move the transducer along the
exact blood vessel having the suspected block if the
trajectory of the vessel is known. The visual indication
means facilitates the presentation of the trajectory of the
blood vessel to the operator resulting in a faster tracking
of the block.
In another alternative embodiment, the means adapted to
provide indication of the trajectory of the blood vessel is
the display system. This enables the operator to view the
current position of the transducer and the trajectory of the

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blood vessel carrying the block or even the block itself if
present. This also facilitates a precise and faster detection
of the block.
The present invention is further described hereinafter with
reference to illustrated embodiments shown in the
accompanying drawings, in which:
FIG 1 is a block diagram illustrating the Ultrasound imaging
apparatus according to the present invention,
FIG 2 is a block diagram illustrating the means providing
indication of the trajectory of the blood vessel,
FIG 3 is a flowchart illustrating the detection of a block in
a blood vessel using the Ultrasound imaging apparatus of the
present invention,
FIG 4 shows a probe head with visual indication means for
providing the trajectory of the blood vessel having a
suspected block, and
FIG 5 shows an embodiment of the visual indication means
where a probe head with a laser light source projects a light
beam on the subject to be examined showing the blood vessel
traj ectory.
FIG 1 illustrates the block diagram of Ultrasound imaging
apparatus according to the present invention. The ultrasound
apparatus uses an ultrasound transducer 10 which transmits
ultrasonic waves to a part of a subject to be examined and
receives ultrasonic waves from the examined part of the
subject, where the waves alternately change over in a time-
sharing manner. The apparatus comprises of a Doppler-mode
processing means 20 which processes the transmitted and
received complex Doppler signals in the Doppler-mode to
produce Doppler images. The blood flow information means 30
is coupled to Doppler-mode processing means 20, for

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determining the blood flow information in the blood vessel.
The determined information consists of the velocity of blood
flow, which is used for detecting the trajectory of the blood
vessel. The apparatus further comprises a display system 40
adapted to display the Doppler image and the B-Mode image.
The apparatus comprises of a B-Mode processing means 50 which
processes, the transmitted and received ultrasonic waves for
obtaining a B-Mode tomographic image. A switching means 60 is
employed to automatically switch between the Doppler
processing means 20 and the B-Mode processing means 50. In
practice while performing an ultrasound imaging the operator
first searches for the blood vessel in which a probable block
is suspected using B-Mode images. Once the blood vessel
carrying the block is detected the image signals are locked
at the blood vessel and the apparatus automatically switches
to the Doppler-mode. In the Doppler-mode the block is
detected using Doppler echoes. Once the block is detected the
apparatus automatically switches to the B-Mode, where the
exact image of the block could be printed out. The apparatus
is also adapted to measure, for example, the velocity of
blood flow by the Doppler method, while observing the B-Mode
tomographic image of the subject in real time. The apparatus
also comprises of an indication means 70 adapted to generate
an audio signal corresponding to a relative position of a
block and the series of ultrasound pulses.
FIG 2 is a block diagram illustrating the means providing
indication of the trajectory of the blood vessel. The means
100 is adapted to provide indication of the trajectory of the
blood vessel corresponding to the blood flow information. The
transducer 10 is connected to the means 100 which can be the
display system 40 or a visual indication means 110 associated
with the ultrasound transducer which provides an indication
of the trajectory of the blood vessel having the suspected
block. One way to present the operator the information is by
displaying the trajectory in the display system. Also the
trajectory could be indicated by providing light sources in a
probe which usually incorporates the transducer.

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FIG 3 is a flowchart illustrating the detection of a block in
a blood vessel using the Ultrasound imaging apparatus. At
step 300, the operator positions the ultrasound transducer on
the subject for examination having a suspected block in a
blood vessel. At step 305, the operator detects the blood
vessel having the suspected block using B-Mode imaging and
prints the said image if required. Once the blood vessel is
detected the image signals gets locked at the blood vessel
and the B-Mode gets automatically switched to Doppler-mode
(step 310). At step 315 the operator obtains the blood flow
information. The trajectory of the blood vessel will be the
same as the trajectory of the blood flow. Operator can get
the trajectory indication using a display system or by means
of any visual indicators for example light source associated
with a probe which carry the transducer. The indicator can
display the trajectory on the surface of the subject which is
examined. At step 320 the operator guides the transducer
along the projected trajectory for detecting the suspected
block. At step 325 the operator detects the block in the
blood vessel using the Doppler echoes. Once the block has
been detected the apparatus is automatically switched to the
B-Mode from the Doppler-mode (step 330), wherein the images
of the block could be printed if required.
FIG 4 shows a probe head with visual indication means for
providing the trajectory of the blood vessel having a
suspected block. The probe is associated with a display panel
400 on the probe head, where the operator is given a visual
indication of the direction, the probe should be moved to
detect the block. The direction indicator 410 in the display
panel points to the same direction of the detected trajectory
of the blood vessel containing the block.
FIG 5 shows an embodiment of the visual indication means,
where a probe head with a laser light source projects a light
beam on the subject to be examined indicating the trajectory
of the blood vessel. The probe 500 comprises a laser light

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source 510 which is adapted to provide a light beam on the
surface of the subject 520 under examination. The direction
of the light beam points to the same direction of the
detected trajectory of the blood vessel containing the block.
A laser point 530 made on the subject by the laser beam
indicated the direction of the blood vessel so that the
operator can follow the laser beam to follow the trajectory
of the blood vessel.
Summarizing, the present invention relates to an ultrasonic
imaging apparatus capable of tracking blocks in blood
vessels. While performing an ultrasound imaging the operator
first searches for the blood vessel in which a probable block
is suspected using B-Mode images. This is made possible by
using the B-Mode processor and a display system. Once the
blood vessel carrying the block is detected the image signals
gets locked at the blood vessel and the apparatus
automatically switches to the Doppler-mode. In the Doppler-
mode a Doppler-mode processor coupled with a blood flow
information means detects the trajectory of the blood vessel
containing the suspected block. Finally the block is detected
using Doppler echoes which are processed by the Doppler-mode
processor. Once the block is detected the apparatus
automatically switches to the B-Mode, where the exact image
of the block could be printed out. The apparatus also
comprises of an indication means adapted to generate an audio
signal corresponding to a relative position of a block and
the series of ultrasound pulses and also a visual indication
means to provide indication of the trajectory of the blood
vessel to the operator.
Although the invention has been described with reference to
specific embodiments, this description is not meant to be
construed in a limiting sense. Various modifications of the
disclosed embodiments, as well as alternate embodiments of
the invention, will become apparent to persons skilled in the
art upon reference to the description of the invention. It is
therefore contemplated that such modifications can be made

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without departing from the spirit or scope of the present
invention as defined

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Patent claims
1. An ultrasonic imaging apparatus, comprising:
an ultrasound transducer (10) that transmits a series of
ultrasound pulses into a subject under examination, and
receives echo signals in response to the series of
ultrasound pulses,
a Doppler-mode processing means (20) that analyzes the
echo signals to produce a Doppler image,
a blood flow information output means (30), coupled to
said Doppler-mode processing means, for determining the
blood flow information in the blood vessel, and
a means (100) adapted to provide indication of the
trajectory of the blood vessel corresponding to the
blood flow information.
2. The apparatus according to claim 1, further comprising a
B-Mode processing means (50) that analyzes the echo signals
to produce a B-Mode image.
3. The apparatus according to claim 2, further comprising a
switching means (60) adapted to switch between the Doppler
processing means (20) and the B-Mode processing means (50).
4. The apparatus according to claim 2 or 3, further comprises
a display system (40) adapted to display the Doppler image
and the B-Mode image.
5. The apparatus according to any of the preceding claims
further comprises an indication means (70) adapted to
generate an audio signal corresponding to a relative position
of a block and the series of ultrasound pulses.

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6. The apparatus according to any of the preceding claims,
wherein the means adapted to provide indication of the
trajectory of the blood vessel is a visual indication means
(110) associated with the ultrasound transducer.
7. The apparatus according to any of the preceding claims,
wherein the means adapted to provide indication of the
trajectory of the blood vessel is the display system (40).

The present invention relates to an ultrasonic imaging apparatus capable of tracking blocks in blood vessels. While performing an ultrasound imaging an operator first searches for the blood vessel in which a probable block is suspected
using B-Mode images. This is made possible by using the B-Mode processing means (50) and a display system (40). Once the blood vessel carrying the block is detected the image
signals gets locked at the blood vessel and the apparatus automatically switches to the Doppler-mode. A switching means (60) is employed to automatically switch between the Doppler
processing means (20) and the B-Mode processing means (50). In the Doppler-mode a Doppler-mode processing means (20) coupled to a blood flow information means (30) detects the trajectory of the blood vessel containing the suspected
block. Finally the block is detected by following the detected trajectory. Once the block is detected the apparatus automatically switches to the B-Mode, where the exact image
of the block could be printed out. The apparatus also comprises of an indication means (70) adapted to generate an audio signal corresponding to a relative position of a block
and the series of ultrasound pulses and also a visual indication means (100) to provide indication of the trajectory of the blood vessel to the operator.