Title of Invention

A SYSTEM FOR SCREENING THE BREAST TISSUE.

Abstract A-system for screening breast tissue, comprising an ultrasound scanning device provided with an ultrasound probe that is capable of generating an image data representing images of cellular tissue. One or more sensors coupled with the probe to determine the probe's location. A viewer to display the image data as images, the viewer providing a rapid, sequential display of scan images. A pad to cover the patient's nipple, said pad being ultrasonically conductive and having different ultrasonic characteristics than breast tissue; and a fabric covering for the breast tissue, adapted to hold the breast tissue in place during scanning, wherein the fabric is capable of absorbing an ultrasonic coupling agent, and transmitting ultrasonic energy with minimal interference.
Full Text DESCRIPTION
A System for Screening the Breast Tissue
Field Of The Invention
The field of the present invention is ultrasonic scanning and diagnostics for cellular
tissue.
Background Of The Invention
Ultrasonic probes have been used for scanning cellular tissue for many years.
Presently, any medical ultrasound examination, whether of the heart, pelvis, abdomen, soft
tissues or any other system, is usually displayed as a number of individual frames or
pictures from a study performed in a dynamic movie-like manner. The usefulness of the
scan, however, is dependent on the skill of the operator, who manipulates the probe by
hand while watching the scan images on a monitor to identify areas of interest. Once these
areas are identified, the operator usually records single or multiple single scan images
showing those areas.
Because the operator must choose a few frames from the large number generated
during the scan, the process is open to error. The operator may fail to select an image of
an important finding, or may select an image that misrepresents the overall findings. In
addition, since the operator is manipulating the probe by hand, and the speed of the probe
over the tissue cannot be correlated with the image capture rate of the probe, the coverage
of the scanned tissue is somewhat haphazard. As a result, the operator does not record a
series of images that represent a contiguous and complete set of images for the entire
scanned tissue. Nor does the manual operation of the probe allow for entirely uniform
coverage of the tissue, even if multiple passes are used.
A second method of recording ultrasonic examinations is used for dynamic
examinations such as echocardiography, where a dynamic recording is made on videotape.
Unfortunately, this analog method is not matched to the digital sonographic recording of
individual frames. Consequently, there is a great loss of detail that prevents the evaluation
of individual frames, which limits the usefulness of the videotape for diagnosing tissue
anomalies. The interpreting physician has no way to vary the speed of playback or to vary
the size of the images. Nor can the physician vary the inherent contrast and brightness of
the images, only the monitor settings. These difficulties lengthen the review time and
prevent optimum viewing. In addition, the use of separate videotapes for individual
patients is expensive, and creates a storage problem.
Specific to screening asymptomatic women for occult breast cancer, there are two
methods presently in widespread use, physical examination and mammography. Both of
these methods are imperfect. Physical examination usually cannot detect cancers smaller
than 1/2 inch in diameter. Some cancers have to be many times larger to be detected.
Mammography is unable to detect as many as 30 percent of cancers smaller than 1/2 inch.
About 5 to 10 percent of larger cancers are mammographically occult. Mammograms also
use radiation and necessitate painful compression of the breasts, which discourage women
from having routine mammograms.
Although not well recognized by the medical community, ultrasound is very
proficient at diagnosing breast cancers if the location of the abnormality is first discovered
by another modality, such as mammography or physical examination. When using
ultrasound as a screening method for the entire breast, however, malignancies are usually
difficult to pick out of the background tissue. In the past there have been two schemes to
use ultrasound for breast screening, but they failed to gain acceptance due to their
unacceptably low success rate in finding cancers.
One method was a water bath system with multiple ultrasound probes and the
breast in a water bath that allowed generation of images of the whole breast in consecutive
slices. These slices could be viewed in sequence at a rate of one every ten seconds.
The second method was to videotape-record the scanning performed by a
technician examining the entire breast. This method had the disadvantage of being
somewhat haphazard in breast coverage. The variable speed of manual motion does not
allow the tissue to be uniformly imaged because the speed is not synchronized to the frame
capture rate of the ultrasound probe. Videotaping also results in a degradation of the
images for the reasons described above.
To date, no method has been developed to uniformly and reliably use ultrasound
probes to create a contiguous and complete set of scan images for an entire area of cellular
tissue, such as a human breast. Ultrasound is usually used to investigate areas of interest
in cellular tissue that have already been identified by other screening methods such as
mammograms, x-rays, and MRI-scans. Ultrasound is not ordinarily used as a screening
tool for cellular tissue anomalies.
Summary Of The Invention
The present invention is directed to an improved system of ultrasonic scanning and
diagnostics of cellular tissue. A sequence of cross-sectional ultrasonic images of tissue are
generated, with means to determine the location of each individual image. The present
invention also presents a systematic method for screening cellular tissue, using cross-
sectional ultrasonic scans.
In a first separate aspect of the present invention, an ultrasonic probe is propelled
over the tissue to be scanned at a uniform speed. Uniform imaging of the tissue can be
achieved.
In a second separate aspect of the present invention, an ultrasonic probe is
propelled over the tissue to be scanned at a uniform speed. The speed of the probe over
the tissue is matched to the image capture rate of the ultrasound scanner. Further uniform
imaging of the tissue can be achieved.
In a third separate aspect of the present invention, an ultrasonic probe is propelled
over the tissue to be scanned at a uniform speed. The angle of the ultrasonic probe may be
adjusted prior to and during the scanning process to maintain optimal contact with the
tissue being scanned. Further uniform imaging of the tissue can be achieved.
In a fourth separate aspect of the present invention, an ultrasonic probe is propelled
over the tissue to be scanned at a uniform velocity, accounting for velocity variations
caused by changes in the angle of the probe in following the contours of the tissue.
Further uniform imaging of the tissue can be achieved.
In a fifth separate aspect of the present invention, an ultrasonic probe is propelled
over the tissue to be scanned at a uniform speed in a substantially straight line, and the
probe's location is adjusted laterally along that substantially straight line to account for
changes in the angle of the probe caused by following the contours of the tissue. Further
uniform imaging of the tissue can be achieved.
In a sixth separate aspect of the present invention, an ultrasonic probe is propelled
over the tissue to be scanned at a uniform speed. The image data from the ultrasonic
probe is converted and stored in a format compatible with a viewer. The data are viewed
with a specialized viewer that allows rapid, sequential playback of the images. An
improved method of scanning tissue for cancers and anomalies is thus achieved. The
viewer can have the capability of allowing the user to select points of interest on
individual scan images, and also select a known reference point on the same or another
individual image. The viewer then calculates the distances between the two points in three
dimensions. The exact location of the point of interest on the patient may thus be
determined.
In a seventh separate aspect of the present invention, location data are collected for
each image frame. This allows an ultrasonic probe to be operated without need for
completely uniform speed, and still allow for accurate location of features or anomalies.
In an eighth separate aspect of the present invention, the images can be viewed to
allow the user to select points of interest on individual scan images, and also select a
known reference point on the same or another individual image, which in breast cancer
screening is usually the nipple. Distances between the two points in three dimensions can
then be calculated. The exact location of the point of interest on the patient may thus be
determined by measuring from the nipple to the point of interest.
In a ninth separate aspect of the present invention, in breast tissue scanning a pad is
placed over the nipple that has different ultrasonic characteristics than breast tissue, and
the scan is performed. The pad shows up in the scan images and identifies the nipple as a
reference point, and reduces the loss of sonic information behind the nipple (ultrasonic
shadowing).
In a tenth separate aspect of the present invention, the breast tissue scanning of the
ninth aspect further includes a covering placed over the breast during scanning to hold the
breast and nipple pad in place and reduce ultrasonic shadowing. Improved imaging is thus
possible.
In an eleventh separate aspect of the present invention, combinations of the
foregoing aspects are contemplated to provide increased advantage.
Accordingly, it is an object of the present invention to provide a system and
method that will allow cellular tissue to be reliably screened for anomalies by ultrasonic
scanning. Other and further objects and advantages will appear hereafter.
Brief Description Of The Drawings
Figure 1 is a block diagram showing the elements of a cellular tissue screening tool
and its interconnections.
Figure 2 depicts a plan view of a patient platform and probe carrier.
Figure 3 depicts a side view of a patient platform and probe carrier.
Figure 4 depicts an end view of a patient platform, and the probe carrier holding an
ultrasonic probe.
Figure 4A depicts a side view of a carrier arm and probe earner holding an
ultrasonic probe and angle sensor.
Figure 4B depicts an end view of a carrier arm and probe carrier holding an
ultrasonic probe and angle sensor
Figure 5 is a schematic diagram showing a plurality of scan rows of scan row
images of a human breast.
Figure 6 is a flow chart describing how the viewing program on the computer
acquires data from the ultrasonic scanner, converts it into digital image data that can be
used by the viewing program, and creates an image file.
Figure 7 is a flow chart describing how a user interface of the viewing program
operates to acquire data from the ultrasonic scanner and create an image file on the
computer.
Figure 8 is a schematic of a preferred embodiment of an image file containing a
plurality of scan row images.
Figure 9 is a flow chart describing how the user interface of the viewing program
operates during playback of images on the computer.
Figure 10 is a flow chart describing the operation of the viewing program's
location function.
Figure 11A is a front view of a fabric covering.
Figure 11B is a rear view of a fabric covering.
Figure 12A is a plan view of a nipple pad.
Figure 12B is a side view of a nipple pad.
Figure 12C is a perspective view of a nipple pad.
Figure 13 is a schematic diagram showing the signals between the angle sensor, the
computer and the motors.
Detailed Description Of A Preferred Embodiment
As shown in Figure 1, a preferred embodiment is comprised of a patient platform 2
to steady the patient and provide a base for the support member 4, the probe carrier 5
connected with the support member 4 that is capable of translational movement to guide
the probe across the tissue to be scanned, a standard medical ultrasound scanning device 6
with an associated probe 8, a remote control device 10 that operates the probe carrier 5, a
standard computer 12, a connection device 14 between the ultrasound device 6 and the
computer 12, and a viewing program that obtains image data from the ultrasound device
and converts it into image data compatible with the viewing program and displays the
images. The medical ultrasound scanning device 6 is a machine that sends and receives
signals from the associated ultrasound probe 8, both of which are usually sold as a single
unit. The ultrasound scanning device 6 with associated probe 8, computer 12, and
connection device 14 are commercially available.
The mechanical carrier 5 holding the ultrasound probe 8 can be connected with the
ultrasound scanner 6. Synchronization between the probe holder mechanical carrier 5 and
the ultrasound scanner 6 can be employed while recording the scans.
Probe Carrier
In order to obtain substantially parallel and contiguous images, a mechanical
device holding the ultrasound probe 8 propels the probe across the tissue to be scanned at
a uniform rate. In a preferred embodiment shown in Figure 3, the mechanism holding the
probe 8 is mounted to a patient platform 16 that steadies the patient during the exam and
acts as a base for the mechanism. The carrier carriage 18 shown in Figures 2 and 3 is
comprised of two parallel vertical members attached to rails 20 beneath the platform and a
horizontal member that is attached to the top of the two vertical members, as shown in
Figure 4. The rails 20 allow the carriage 18 to move along the length of the platform, or
the x-axis, as shown in Figures 2 and 3. Attached to the horizontal member between the
two vertical members is another vertical member with an attached semi U-shaped member,
called the carrier arm 22, which is attached to a carrier 24 holding an ultrasound probe 8.
The carrier arm 22 is attached in such a manner that allows it to move along both the y-
axis and the z-axis, so that it can move both across the patient and nearer/further from the
patient on the platform, as shown in Figure 4. The carrier 24 itself is articulated to hold
the probe at any desired angle relative to the patient by rotating about the x and y axes.
The carrier 24 may hold the probe 8 at a fixed angle during scanning, or can adjusted
during the scanning process to keep the probe 8 perpendicular to the patient's skin (or any
other preferred orientation).
To protect the carriage assembly when not in use, and to prevent the patient from
becoming entangled in it when first lying on the platform, the assembly is housed in a
"garage" 26 at one end of the platform 16. In a preferred embodiment, the carriage 18 is
propelled along the x-axis of the platform 16 by one or more motors that are controlled by
a microprocessor. The carrier arm 22 is also moved along its two axes during scanning by
one or more motors controlled by one or more microprocessors. The microprocessors)
can be separate from the computer 12 that operates the viewing program (described
below), or the computer 12 can be used for this purpose. The carrier arm 22 moves along
the z-axis to maintain consistent contact between the probe 8 and the patient's skin during
scanning. The carrier arm 22 maintains a constant pressure of the probe 8 on the patient,
with a user-selected preset value. This pressure is monitored during the scan and an
override function will move the carrier arm 22 up and away from the patient in the z-axis
if a maximum pressure level is detected. In another embodiment, the operator will
maintain the pressure manually during the scanning process, and the pressure may be
measured using pressure transducer(s) in close proximity to the probe head. The carrier
arm 22 will move upward to clear the patient at the end of the scan. A manual override on
the remote control 10 is also available to move the carrier arm 22 away from the patient
when there is a panic or emergency situation.
In other embodiments, the carriage 18 and carrier arm 22 can be either on a parallel
track arrangement (one sided or multi-sided), or be comprised of an articulating arm or
some other contrivance, located over, underneath or adjacent to the patient (with or
without the use of a patient platform) positioned either upright or prone. The carrier arm
22 need not be supported by a carriage assembly connected to the patient platform, but
could be independently suspended from the ceiling, wall, or floor, providing translational
movement in both the x and y directions relative to the patient platform. The carrier
mechanism could be similar to carriage mechanisms currently used to support x-ray
machines, with means added to provide the requisite movement of the probe. The probe
may be supported and propelled by a mechanical carrier by any means (manually,
mechanically, electrically, hydraulically, pneumatically or by any other means, with or
without control feedback), or any combination of methods. These methods, singularly or
combined may be utilized to control the probe in the X, Y and Z-axes. Gravity may also
be employed to provide the requisite pressure of the probe on the patient, or assist in the
propulsion of the probe across the tissue.
The probe 8 may be designed as a permanent or removable component of the
mechanical carrier 24. The carrier 24 may be designed with or without an onboard
integrated ultrasound machine 6, ultrasound probe 8, and or ultrasound probe interface.
As shown in Figures 4A and 4B, the carrier 24 can be articulated to change the
angular position of the probe 8 prior to or during scanning either manually, or by one or
more motors controlled by one or more microprocessors. The microprocessor(s) can be
separate from the computer 12 that operates the viewing program (described below), or the
computer 12 can be used for this purpose. If the probe itself has an articulating head, the
carrier may not need to be articulated.
In an embodiment where the probe's 8 angular position is adjusted automatically
during scanning, the pitch and roll adjustments are triggered by one or more displacement
transducers positioned around the ultrasound probe 8. In this embodiment, all the data
related to the position and angle of the probe 8 may be provided to the viewing program to
allow the images to be correlated with their corresponding location on the patient. The
position data may allow the program to compensate for the overlapping of, or gaps
between images. The measurement system can be by any means or convention and may
consist of any or all of x, y, and z-axes and/or the probe angular position.
The speed of the carrier 24 holding the probe 8 is precisely controlled by a
microprocessor. The speed may be correlated with the capture rate of the ultrasonic
scanning device 6. The uniform speed of the probe face 9 over the tissue results in images
that are uniformly spaced, which allows the viewing program (discussed below) to
calculate the position of a selected point on any image. In an embodiment where the probe
is held at a fixed angle during the scan, the uniform spacing is all that is necessary to
determine the position of each frame of the scan on the patient. The ultrasound scanning
device 6 may act as a controller in communication with the probe 8 to sequentially activate
the probe 8 as it moves across the tissue, but any other controller could be used to activate
the probe, including a computer linked to the probe or the scanning device or both.
The operator may determine the amount of area to be scanned, and input various
parameters of that area into the computer's 12 positioning program. For example, when
used for breast tissue scanning, the operator will measure across the skin, providing the
total length to be traversed by the probe 8. In current practice, the width of the tissue
scanned by the ultrasound probe 8 is generally too small to capture an image of an entire
organ such as the breast. As a result, several adjacent passes are performed to provide
complete coverage. Each pass (called a scan row 30) will have some overlap with the
preceding pass, to achieve full coverage and eliminate the potential for missing features at
the fringes of the scan. Prior to each successive pass, the carrier arm 22 lifts away from
the patient, moves along the y-axis across the breast and along the x-axis to the top of the
of the area to be scanned to position itself for the next scan row 30, then lowers itself
along the z-axis onto the patient. Alternatively, the carrier arm 22 may be raised or
lowered manually.
A scan row 30 contains a plurality of individual images or frames 28, typically
about 200 to 300 for a breast. Figure 5 depicts how the frames 28 in scan rows 30 are
aligned on a typical breast scan, but for clarity, no overlap is shown. A scan row 30 can
be thought of as a stack of photographic slides, each slide representing an individual frame
28. The frames 28 are evenly spaced, which may be accomplished by uniform motion of
the probe 8 and uniform timing of the scans. The frames 28 are most conveniently
substantially parallel to each other.
In an embodiment where the probe's angle is changed during scanning, the probe 8
is attached to a carrier 24 that allows the probe 8 to be pivoted in any direction. The roll
plane 11 refers to the forward and backward pivoted movement of the probe 8 along the x-
axis at the roll plane pivot 100. See Figures 4A and 4B. The pitch plane 13 refers to the
left and right pivoted movement of the probe 8 along the y-axis at the pitch plane pivot
102. The pitch and roll pivots 100, 103 allow the probe to maintain full contact between
the probe face 9 and the skin surface by allowing the probe 8 to be positioned at a
perpendicular angle to the skin regardless of skin contour, to allow for optimal ultrasonic
imaging. A commercially available angle sensor 25 may be attached to the carrier 24 so
that it is parallel to the probe 8 at all times in both the roll plane 11 (x-axis) and the pitch
plane 13 (y-axis), see Figures 4A and 4B The angle sensor 25 sends the roll and the pitch
angles to the positioning program in the computer 12 at short regular intervals, one tenth
of a second in a preferred embodiment. Figure 15 is a schematic diagram of the signals
between the angle sensor, the computer and the motors.
Where the probe 8 is dynamically angled as the probe 8 is moved over the tissue,
particularly where the tissue is not flat, several problems arise in achieving proper speed
and location during the scan. For example, when trying to uniformly scan a convex
object, such as a breast, the degree of convexity of the breast is unknown in both the 'x'
and 'y' axes. Using a breast as an example, if the probe 8 is propelled at a constant speed
along the x-axis, the speed of the probe face 9, in reference to the skin, will increase on the
upslope and the downslope of the breast. In addition, since the roll plane pivot 100 in the
carrier 24 is some distance above where the probe face 9 touches the skin (called the
fulcrum length 27), the probe face 9 and the carrier 24 will not be in the same position
along the x-axis when the probe 8 is pivoted in the roll plane. Thus the carrier 24 will be
behind the probe face 9 on upslopes and in front of it on downslopes.
Location sensors could be used to track the location of the carrier 24, and the
angular position of the probe 8, for accurate location and speed corrections. Sensors may
determine the carrier's 24 location by counting the number of rotations of the motors
controlling the movement of the carrier arm 22 in the 'x' and 'y' directions. The probe's 8
angular position may be determined by the angle sensor 25. These location sensors are
"coupled" with the probe even though no direct connection to the probe may exist.
Speed correction over the skin may be implemented with an angle sensor 25
attached to the probe 8 that sends the probe's 8 angle in both the 'x' and 'y' axes to the
controlling computer 12 continuously, at least ten times per second. The change of angle
in the V axis may be used to properly adjust the velocity for the next increment of time
by applying a two-term trigonometric formula. The first term maintains a constant speed
along the skin by decreasing the horizontal speed of the carrier 24 as the probe 8 gains
vertical speed by climbing or descending along the slope of the breast The second term
accounts for the effect of the pivot in displacing the carrier arm 22 relative to the probe
face 9. Therefore, the angle sensor 25 provides angle data to the positioning program
residing on the computer 12, which controls the x-axis motor to produce uniform velocity
of the pivoted probe 8 over the skin of the breast, while continuously changing only the
horizontal (x-axis) velocity. To produce the desired constant velocity, the positioning
program uses the cosine of current roll angle to calculate the x-axis motion vector. The
positioning program also compensates for the horizontal component of the offset of the
carrier 24 from the probe face 9 produced by the position of the roll plane pivot 100 in the
carrier 24 being above the probe face 9. The positioning program uses the absolute
change of the sines of the roll angle between the present angle and the angle in the
previous time interval, using the following formula:
HV = (DV * cos(NRA) + (FL/TI * (isin(ORA) - sin(NRA)D)
Where:
HV = Horizontal Velocity (of the carrier arm 22 necessary to produce DV at the present
roll angle)
DV = Default Velocity (desired velocity of the probe face 9 over the skin)
FL = Fulcrum Length (distance between the roll plane pivot 100 and
the center of the probe face 9)
TI = Time Interval (time in seconds between angle measurements)
ORA = Old Roll Angle (Angle of probe 8 along x-axis in last time increment)
NRA = New Roll Angle (Angle of probe 8 along x-axis at present)
If the computer 12 clock and the software that receives signals from the angle
sensor 25 are not precisely matched, the time intervals (TI) in the above equation can be
slightly different. Although in a preferred embodiment the cycles are sufficiently long to
cancel out each of the small differences, to prevent errors introduced by these variable
length time intervals, an additional correction factor can be used. Velocities can be
requested for set intervals to achieve specific distances along the x and y-axes, but the
inexactness of the time intervals may result in approximate rather than exact distances
with each move. These small errors summated over an entire row could be significant and
result in errors in row length and width. The solution is to interrogate the exact position of
the probe 8 along the length of the x and y-axes after each time interval, and correct any
small error during that time interval and convert that distance into a velocity to be added
or subtracted during the next time interval. The positioning program records the number
of rotations of the motors driving the horizontal (x-axis and y-axis) motion, from which
the exact position of the probe 8 can be calculated.
The fact that the probe can be angled in the pitch plane 13 creates an additional
lateral correction factor, using data from the location sensors. Like the roll plane pivot
100, the pitch plane pivot 102 is above the probe face 9, so any angulation in the y-axis as
a result of the curvature of the tissue, such as on a breast, will cause the probe 8 to deviate
from its straight-line course. If this lateral movement is not corrected, it will result in a
curved row, and gaps in tissue coverage. Again, using the change in angle sent by the
angle sensor 25 and a one-term trigonometric formula, the positioning program on the
computer 12 can signal a y-axis motor to continuously change the lateral position of the
probe 8 to maintain straight rows. To maintain straight travel over a convex surface, the
positioning program calculates the correction of the y-axis position, using the change of
the sines of the previous and the present pitch angles. The effect of canting the probe 8 in
the pitch plane 13 adds another term to compensate for additional movement of the probe
This term is subtracted from the first term, and is the change of the cosines of the previous
and the present pitch angles, using the following formula:
YCD = (PFW * (sin(OPA) - sin(NPA))) - ½ PFW * (cos(OPA) - cos(NPA))
Where:
YCD = y-axis Correction Distance (of the probe 8 to correct for the offset from the
change in y-axis angle from the previous time increment)
PFW = Probe Face Width (width of the probe face 9)
OPA = Old Pitch Angle (Angle of probe 8 along y-axis in last time increment)
NPA = New Pitch Angle (Angle of probe 8 along y-axis at present)
To maintain complete coverage, the carrier 24 must move the width of the probe
face 9 over the skin, rather than along the 'y' axis, when beginning its next row. The
sensors may be used to provide location data to the positioning program, which
continuously records the maximum y-axis angle and uses the maximum angle in each row
in a one-term trigonometric formula, and calculates the distance to move the probe 8 along
the y-axis so that no skip area will occur. To assure that no tissue will be skipped, the
rows overlap slightly, and the initial starting position of each row should be calculated to
assure overlap. The positioning program uses the difference of the sines of the initial pitch
angle and the maximum pitch angle in a row to calculate the distance to move the carrier
24 on the y-axis to begin the next row, using the following formula:
NRO = (cos(MPA) * PFW) - OA
Where:
NRO = Next Row Offset (of the probe 8 to avoid skip areas)
PFW = Probe Face Width (width of the probe face 9)
MPA = Maximum Pitch Angle (in the present row)
OA = Overlap Amount (of the contiguous rows)
In the embodiment where the probe's 8 angular position is dynamically adjusted
during scanning to follow the contours of the tissue being scanned, the tops of the frames
28 are substantially evenly spaced, and the tissue contours will be sufficiently gentle that
adjacent frames 28 will remain substantially parallel to each other, although they may
differ by as much as a few degrees. Although adjacent frames 28 within a single scan row
30 are substantially parallel, frames 28 may become progressively less parallel as they are
separated by an increasing number of frames 28. Frames 28 in two adjacent scan rows 30
are not necessarily substantially parallel.
In a preferred embodiment, an organ such as a breast can be scanned in one
segment, with the scan rows 30 progressing across the entire breast from lateral to medial,
or vice-versa. Figure 5 depicts a series of scan rows 30 comprising one segment. In other
embodiments, each breast may be scanned in two segments, with the first scan row of each
segment aligned at the center of the breast at the nipple and successive scan rows 30 being
progressively further from the nipple.
Viewing Program
A preferred embodiment of the viewing program (or viewer) is a streamlined,
monolithic, 32-bit Windows application designed to run on Windows 95, Windows 98, NT
4, and Windows 2000. A preferred embodiment is implemented to interface with and
acquire data from the General Electric Logiq 700 medical ultrasound scanner. The
viewing program could, of course, be written to run on other types of computer systems
and future versions of operating systems, and to interface with other types of scanning
devices. As used in the claims, "computer" generically refers to any suitable device using
one or more microprocessors to process data.
The viewing program's monolithic structure and relatively small size allow it to be
bundled with the image data for ease of transport and viewing flexibility. In most cases,
complete scan data for a patient and the program can be placed on a single CD, allowing
the user to transport a number of patient scans in a relatively small package, and view
them on any computer that is compatible with the software on the CD. Although it would
be even more convenient to transmit scans via e-mail, the current speed and size
limitations of e-mail make sending the entire scan impractical. If desired, however, the
viewing program can select small segments of the scan data and bundle it with the viewing
program, for a small data package that is practical to send via current e-mail systems.
Other delivery options could also be utilized, such as streaming video over the internet, or
discrete file downloads using file compression to speed download time. In addition, the
viewer can export or print single frames 28 in a standard image format, such as bitmap.
In other embodiments, the viewing program could be designed to operate solely on
a computer on which it resides, or it could be resident on a server in a client-server
environment. The program could also be non-monolithic, using Java or a similar
language, in a network-centric environment.
In a preferred embodiment shown in Figure 1, the viewer program controls the
scanning operation and data offloading via a connection device 14, such as a network
TCP/IP interface. Other connection devices could be used, or with certain scanners, none
may be needed. The General Electric Logiq 700 ultrasonic scanning device has an internal
buffer that can store a finite amount of image data before offloading is required to clear
the buffer for another scan. Other scanning devices have no such buffer, but instead
provide an output of streaming data as the scan is being performed, and the program is
capable of acquiring image data from a variety of scanning devices.
In a preferred embodiment, the computer acts as a receiver and recorder for the
ultrasonic images obtained from the ultrasonic scanning device. As shown in Figure 6, a
preferred embodiment uses a handshake sequence between the viewer and scanner to
begin the scan acquisition process 32. The viewer then invokes the scanner to clear its
internal frame buffer 34 and then to acquire a scan row to its internal buffer 36. The
viewer freezes the scanner buffer 38, determines the number of frames 28 in the buffer,
their dimensions and pixel format 40, initializes a new scan row in the image file 42, reads
individual frames 28 from the buffer 44, counts the frame format 46 and writes them into
the image file 48 on a data storage device. It then repeats the acquisition process until all
the frames 28 in the scan row are processed 50, and terminates the scan row in the file 52.
It then starts all over with additional scan rows 30 until the entire scan is acquired in the
image file 54. A preferred embodiment of the viewer uses a proprietary image file format,
which contains a header for patient information and scan information ("image file"), but
images could also be converted into standardized formats such as DICOM.
Figure 7 is a flow chart showing the user interface for the data transfer process
from the scanner to the computer. The user creates a new file by choosing from the file
menu 56, specifies a name for the new file 58, enters the patient data and relevant
information 60, makes a selection from the data menu 62, and specifies what segment of
the breast is about to be acquired 64. The user then begins the acquisition process 66, and
frames 28 are then offloaded sequentially from the scanner's frame buffer via a connection
device 14, such as a network interface, then normalized, compressed losslessly (if desired)
and written sequentially to the image file, said file recorded on a data storage device.
When all buffered frames are processed, the viewer terminates the constructed row in the
image file 68. Another scan row can then be acquired and so on, or the interface to the
scanner may be terminated 70. For offloading streaming data, the program performs a
real-time write-through.
Acquiring The Data
In a preferred embodiment, the viewer creates (and subsequently displays)
proprietary image files, the format of which consists of a file header 72, a patient
information block 74, and zero or more blocks of scan row frames 76, as shown in Figure
8. The patient information block 74 contains not only information about the patient, but
also information about the scan itself, such as the depth and width of the scan, length of
the scan row, speed of the carrier 24 during the scan, the number of frames per second
captured by the scanner, the spacing between each frame, etc
In another embodiment where the probe's angular position is dynamically adjusted
during the scan, the viewer program may record on a data storage device the angular
position of each frame and other information for each frame. The angular position data
can be provided to the viewer program though the scanner 6, from angle sensor 25
attached to the probe 8 or the carrier 24, or from an intermediary computer program that
gathers this data.
The viewer is implemented to be largely independent of the particular scanner
hardware with which it is paired. A specific module written for each scanner is
responsible for "normalizing" data from the internal format used by that particular scanner
to the format used within an image file. The computer acts as a conversion device to
convert this scanner data into the viewer's image file format. Scan row frame elements
stored in an image file are written in a format optimized for rapid rendering during
display. In a preferred embodiment, the viewer is run on computers using a WFN 32
operating system, and scan frames 28 are written to image files in an 8-bit format that
closely mirrors 8-bit grayscale Windows DEB (device-independent bitmap) format. This
allows the images to be efficiently displayed on a Windows computer with practically no
routine translation.
Displaying The Images
After acquiring, converting, and storing the scan data, the second major task of the
viewer is to display the scan images. The viewer opens a previously created image file
and renders sequential scan row frames within its interface in a "movie-like" manner. The
images can be played at variable speed, backward or forward, and can pause on a single
frame.
The user interface for the viewing program may look and operate in largely the
same manner as commercially available digital video players, such as Microsoft Windows
Media Player, with buttons for Play, Pause, Stop, a slider bar to move back and forth
within segments, etc. The playback features may utilize standard Windows input/output
operations commonly used in digital video applications. A generalized flow diagram
showing the user interface steps for playback operation is shown in Figure 9.
One of the viewer features is a location function, which determines the physical
location (on the patient) of any point on any frame 28 given any selected reference point
on the same frame, or on a different frame. For example, if a physician finds an
abnormality on one frame, he needs to then be able to locate some prominent feature
elsewhere in the frame data, i.e., the nipple or a temporary mark placed by the operator,
and then find the position of the abnormality relative to that reference point.
The user interface for the location feature operates as shown in the flowchart in
Figure 10. The user marks the point-of-interest ("POl") on a particular frame 28 being
viewed 78 by double-clicking it with the computer mouse 80. An overlapped window
then appears, and within that window a small display pane shows "thumbnail"-sized
sonograph frames taken from the scan rows (actually, the same row "segment") in which
the abnormality lies 82. The user can then traverse through the thumbnailed frames until
he locates a reference frame containing a reference point ("RP") he wishes to use 84. Jn
the case of a breast scan, the RP will often be the nipple, which can be positively identified
by placing a special pad 120 over the nipple during the scan, readily identifiable on the
viewer image. The user can then mark a point on that reference frame using the mouse 84
The viewer program immediately calculates the first position relative to the reference
point 86 and displays the results (in both textual and graphical format) to the user 88. The
user then closes the dialog box to end the function 90.
To implement the location function, the viewer takes advantage of the data known
about the scan, which is written in the image file's header as part of the data acquisition
process. Such information includes the width of the frame, and the distance between
subsequent frames in a particular scan row, and the offset between scan rows. Within an
individual frame, the location function calculates the position of a user-selected point by
proportional math, using the number of image data points (pixels) in the height and width,
and the size of the frame, to calculate the distance of the point from the sides of the frame.
The program counts the number of pixels across the width of the frame, then the user-
selected pixel position number is multiplied by the frame width and divided by the total
number of pixels. For example, assuming the frame width is 4 centimeters, the program
counts 400 pixels across that width, and the user selected a point at pixel position 100: 100
* 4 cm / 400 = 1 cm. So the selected point is 1 centimeter from the side of the frame. The
program then performs a similar calculation to determine the selected point's distance
from the top of the frame. Figure 10 depicts this process and also shows how the location
function determines the distances and angles from a user-selected point of interest (POI) to
a user-selected reference point (RP), using the known values and simple trigonometry 86.
In breast cancer screening, the POI is usually a suspected cancer, and the RP is the nipple.
The substantially uniform motion of the probe 8 results in evenly spaced frames
28, and thus the distance from a reference frame to a particular frame is calculated by
counting the number of frames between them and multiplying by the spacing 86. In
addition, the overlap of each scan row is known, and thus if the RP is in a different scan
row than the POI, determining the location is a simple matter of determining the overlap
and measuring the distance, and using trigonometry to make any angular and remaining
distance calculations 86. Therefore, counting the frames from the RP and taking into
account their overlap provides the location of each individual image.
In a preferred embodiment where the angular position of the probe is dynamically
adjusted during the scanning process, the viewing program may obtain each frame's
angular position during the scar, from the angle sensor 25, along with the other
information described above. Using that information, the location function may again use
simple trigonometry to calculate the distances between the RP and the POI.
Another feature of the viewer is its ability to accurately measure the distance
between two user-selected points on a single frame. This allows the user to measure
anomalies or features found in the images. The process for measuring is very similar to
the location function process. Using the known values for frame depth and width, the
measuring function uses proportional math to determine the distance between the two
points. To measure diagonally across a frame, proportional math is used to determine the
lengths of the triangle legs, and simple trigonometry is used to calculate the length of the
hypotenuse, which is the distance between the points.
Carrier-less Embodiment
It is possible to obtain the sequential scans without the use of a carrier. The probe
may be coupled with one or more location sensors to provide location data that is
correlated with each individual frame. The term "coupled" means the sensors could be
attached to the probe itself, or used to track the probe's movement without actual
attachment. These sensors may provide feedback to the operator to move the probe over
the tissue at the correct speed, and to start each scan row in the correct position. This will
allow sufficiently complete coverage of the tissue without the need for a mechanized
carrier. Alternatively, to obtain relatively uniform spacing of the frames, a speed sensor
on the probe could signal the ultrasound scanning device to vary the frame capture rate to
match the speed of the probe as it is moved across the tissue.
This camer-less embodiment does not necessarily rely on the precise movement of
the carrier to provide uniform spacing between the frames of a scan row in order to
calculate distances between frames. Because location data are available for each frame,
the location function of the viewer can use the location information of the POI frame and
compare it to the location information of the RP frame, and make the requisite distance
and trigonometric calculations to determine the distances from the RP to the POI.
The location sensors can be arranged in a variety of implementations. A simple
inclinometer can be used to determine the orientation of the probe in two or three axes.
The location of the probe face 9 could be tracked by an inertial sensor system, or a laser or
infrared system, or a radio frequency local positioning system. Alternatively, a simple
wheel device could be used to measure distances as well as the speed the probe is being
moved over the tissue. Alternatively, an optical movement sensor, such as those
commonly used in optical mice, or a laser interferometer, could be attached to the probe to
track its movement. When used for scanning breast tissue in conjunction with a covering,
the covering could be made of some type of fabric that is compatible with an optica)
movement sensor. All of these systems could use a point on the body as a reference
location, such as the nipple when the system is used for breast scanning.
Method For Tissue Screening
The above-described devices, the probe, scanner, carrier, and viewing program,
can be combined to provide a method to scan for anomalies in cellular tissue, such as
cancers. The tissue is scanned, and the user views the images on a computer, rapidly
scanning through the images in a "movie-like" fashion. This technique causes any
anomalies in the tissue to become visible during the rapid sequential playback, as they
distort or disrupt normal fibrous planes or sheets The user can then run the images back
and forth until the frame containing the anomaly is found, and the user can mark that
anomaly and locate it using the location function of the program. The viewer program
emits an audible and/or visual signal that marks the end of each scan row 30 or segment to
allow the user to know the approximate location without having to look away from the
images. The viewer can also play a continuous loop with user-selected start and end
points. Follow-up studies can be performed using the location information, including a
more focused ultrasound investigation, biopsy, etc.
Individual images can be manipulated using image software such as Photoshop,
using filters and other manipulation techniques to enhance the appearance of the
anomalies and make them more visible, including image magnification. Brightness and
contrast of the frames can be adjusted. In addition, a variety of image enhancement
algorithms are commonly known in the art and the viewer program allows them to be used
"on the fly" as the images arc displayed in rapid succession.
It is anticipated that the image review process could eventually be automated, once
software is developed to identify any anomalies. If necessary, the user could then study
the images to determine the accuracy of the software's identification.
For scanning breast tissue specifically, a preferred methodology is as follows. The
mechanical probe carrier 24 is used, and depending upon the size of the probe, the breast
may be scanned in strips or in its entirety, in either multiple passes or a single pass,
respectively. The breast may be scanned with or without a covering. Figures 11A and
1 IB show a bra-like covering 92 that may aid in holding the breast in position for
screening, as well as assisting in uniform integrity of image gathering by reducing
information loss from ultrasonic shadowing. The covering 92 also provides some modesty
for the patient. Current ultrasound technology requires the use of sonographic coupling
agent, usually a gel, to exclude any air between the probe and the skin. Therefore, any
such covering 92 would have to be capable of absorbing the gel, be relatively transparent
to ultrasonic energy, and have a sufficiently loose weave so that any air trapped between
the skin and the covering 92 may easily escape. The covering 92 could be pre-
impregnated with the coupling agent, or the agent could be applied by the operator just
prior to the scan, or both. To avoid having the patient pull a gel-soaked covering 92 over
her head after the scan is completed, the covering 92 could be designed to dismantle after
use. The covering 92 can be equipped with a seam in the back 94 that is constructed with
chain stitching that is easily undone so that the covering 92 may be removed by slipping it
off the patient's arms. The shoulder seams 96 could also be made with chain stitching to
further ease removal. Since a preferred embodiment of the covering 92 is designed to be a
single-use item, the covering 92 could be cut off with scissors without the need for special
stitching. Zippers, hook and loop, or other fasteners could also be used to ease the putting
on or removal of the covering 92, and would allow the covering 92 to be re-used. A
preferred embodiment uses a stretch fabric for the covering 92, but any suitable material
that can conduct or pass through ultrasonic energy could be used.
A nipple pad 120 is placed on the patient's nipple to provide a reference point on
the images. The nipple pad 120 shows up on the scan images due to its ultrasonic
characteristics that distinguish it from the breast tissue. The nipple pad 120 has the added
benefit of reducing ultrasonic shadowing. Figures 12A, 12B and 12C depict a preferred
embodiment of a nipple pad 120, which is made of an ultrasonically conductive material,
such as a solid gel. A preferred embodiment of the nipple pad 120 is approximately 70
mm in diameter and varies in thickness from less than 1 at the periphery to 4 mm at the
center, but other sizes could be used. Larger and thicker gel pads are commercially
available for isolated ultrasound scans, where offsetting the probe from the tissue is
advantageous, but they are not designed to be completely traversed across their periphery
during a scan. As shown in Figures 12A, 12B and 12C, the circular nipple pad 120 is
tapered to an edge 122 about its full periphery, and has a very smooth surface. The edge
122 of the nipple pad 120 is thick enough to resist tearing, yet thin enough to allow the
ultrasound probe to traverse its periphery during scanning without dislodging the nipple
pad 120 or causing an ultrasonic shadow at the nipple pad's edge 122. The nipple pad 120
may be held in place by positioning it beneath the above-mentioned fabric covering 92.
As described above, the images are reviewed in a rapid sequential fashion,
imparting a sense of motion through the breast tissue. The reviewer can observe or detect
a disruption of the normal breast architecture through comparative image analysis or
observation. The method has advantages over other ultrasound scanning techniques,
including the following:
1) Parallel and contiguous images are obtained, optimizing the coverage of the
breast tissue and improving the appearance of the images when viewed in a "movie-like"
fashion.
2) The entire breast is imaged in a uniform and reproducible manner.
3) The images may be maintained and reviewed singularly, in strip form, or
assembled to represent an entire breast, such as 3-D reconstruction.
Accordingly, an improved ultrasonic cellular tissue screening tool is disclosed.
Although embodiments and applications of this invention have been shown, it would be
apparent to those skilled in the art that many more modifications are possible without
departing from the inventive concepts herein. The invention, therefore, is not to be
restricted except in the spirit of the appended claims.
We claim
1. A system for screening breast tissue, comprising
an ultrasound scanning device provided with an ultrasound probe that is capable of
generating an image data representing images of cellular tissue;
one or more sensors coupled with the probe to determine the probe's location;
a viewer to display the image data as images, the viewer providing a rapid, sequential
display of scan images;
a pad to cover the patient's nipple, said pad being ultrasonically conductive and
having different ultrasonic characteristics than breast tissue; and
a fabric covering for the breast tissue, adapted to hold the breast tissue in place during
scanning, wherein the fabric is capable of absorbing an ultrasonic coupling agent, and
transmitting ultrasonic energy with minimal interference.
2. The system as claimed in claim 1, optionally comprising
a receiver to receive image data from the ultrasound scanning device.
3. The system as claimed in claim 2, optionally comprising
a recorder in communication with the receiver to store the image data.
4. The system as claimed in claim 2, optionally comprising
a conversion device in communication with the receiver that converts the image data
into a format compatible with the viewer.
5. The system as claimed in claim 1, optionally comprising
a pad to cover the nipple of the breast tissue, the pad being ultrasonically conductive and
having different ultrasonic characteristics than breast tissue, said pad placed beneath the
fabric covering and held in place by the fabric covering.
6. The system as claimed in claim 1, optionally comprising
a carrier driven to more progressively over the cellular tissue, the probe being mounted to the
carrier to generate a series of cross-sectional images of the cellular tissue that are substantially
parallel to adjacent images in the series.
7. The system as claimed in claim 6, optionally comprising
a controller in communication with the probe to sequentially activate the probe during
progressive movement of the probe over the cellular tissue.
8. The system as claimed in claim 6, optionally comprising a computer
that controls the progressive movement of the probe and is matched to
the frame capture rate of the ultrasound scanner.
9. The system as claimed in claim 6, optionally comprising
a platform to stead the patient,
a carrier arm mounted for translational movement relative to the platform,
when the carrier is connected with the carrier arm, the probe is connected with the
carrier, the probe being pivotally mounted related to the carrier arm about at least one axis.
10. The system as claimed in claim 9, optionally comprising
at least one motor controlled by at least one microprocessor to drive the probe and the
carrier over the cellular tissue.
11. The system as claimed in claim 9, optionally comprising
at least one motor controlled by at least one microprocessor to adjust the angular
position of the probe.
12. The system as claimed in claim 11, optionally comprising an
additional system for dynamically adjusting the angular position of the
probe, including
one or more displacement sensors proximate to the probe;
wherein the displacement sensor(s) produces signals that are sent to the at least one
microprocessor, which in turn produce signals that are sent to the at least one motor to adjust
the angular position of the probe.
13. The system as claimed in claim 10, wherein the at least one
microprocessor determines the velocity of the probe face over the skin
based on the motor speed and the probe's angular position, and sends
signals to the at least one motor to maintain a uniform velocity.
14. The system as claimed in claim 13, wherein the at least one
microprocessor calculates the proper velocity using the following
formula
HV = (DV* cos(NRA) + (FL/TI * (lsin(ORA) - sin(NRA)1))
Where:
HV = Horizontal Velocity (of the carrier arm necessary to produce DV at the present roll
angle)
DV = Default Velocity (desired velocity of the probe face over the skin)
FL = Fulcrum Length (distance between the roll plane pivot and the center of the probe face)
TI = Time Interval (time in seconds between angle measurements)
ORA = Old Roll Angle (Angle of the probe alone x-axis in last time increment)
NRA = New Roll Angel (Angle of probe along x-axis as present)
15. The system as claimed in claim 10, wherein the at least one
microprocessor determines the lateral position of the face of the probe
during the scanning process and sends signals to the at least one motor
to make position corrections.
16. The system as claimed in claim 15, wherein the at least one
microprocessor calculates the later position corrections using the
following formula
YCD = (PFW * (sin(OPA) - sin(NPA))) - ½ PFW * (cos(OPA) - cos(NPA))
Where:
YCD = y-axis Correction Distance (of the probe to correct for the offset from the change in y-
axis angle from the previous time increment)
PFW = Probe Face Width (width of the probe face)
OPA = Old Pitch Angle (Angle of probe along y-axis in last time increment)
NPA = New Pitch Angle (Angle of probe along y-axis at present).
A-system for screening breast tissue, comprising an ultrasound scanning device provided
with an ultrasound probe that is capable of generating an image data representing images
of cellular tissue. One or more sensors coupled with the probe to determine the probe's
location. A viewer to display the image data as images, the viewer providing a rapid,
sequential display of scan images. A pad to cover the patient's nipple, said pad being
ultrasonically conductive and having different ultrasonic characteristics than breast tissue;
and a fabric covering for the breast tissue, adapted to hold the breast tissue in place during
scanning, wherein the fabric is capable of absorbing an ultrasonic coupling agent, and
transmitting ultrasonic energy with minimal interference.

Documents:

411-KOLNP-2003-FORM-27.pdf

411-kolnp-2003-granted-abstract.pdf

411-kolnp-2003-granted-assignment.pdf

411-kolnp-2003-granted-claims.pdf

411-kolnp-2003-granted-correspondence.pdf

411-kolnp-2003-granted-description (complete).pdf

411-kolnp-2003-granted-drawings.pdf

411-kolnp-2003-granted-examination report.pdf

411-kolnp-2003-granted-form 1.pdf

411-kolnp-2003-granted-form 18.pdf

411-kolnp-2003-granted-form 3.pdf

411-kolnp-2003-granted-form 5.pdf

411-kolnp-2003-granted-gpa.pdf

411-kolnp-2003-granted-reply to examination report.pdf

411-kolnp-2003-granted-specification.pdf


Patent Number 225444
Indian Patent Application Number 411/KOLNP/2003
PG Journal Number 46/2008
Publication Date 14-Nov-2008
Grant Date 12-Nov-2008
Date of Filing 04-Apr-2003
Name of Patentee SONOCINE, INC. ,
Applicant Address 445 28TH AVENUE, VENICE, CA
Inventors:
# Inventor's Name Inventor's Address
1 PONCE LUIS E 718 SUNSET BOULEVARD, #C, ARCADIA, CA 91107
2 KELLY KEVIN 445 28TH AVENUE, VENICE, CA 90291
3 ROYCE ROGER 445 28TH AVENUE, VENICE, CA 90291
4 PETERSON RICHARD J 1116 BENNETT #7, LONG BEACH, CA 90804
5 UNDERBRINK CHRISTOPHER M 1359 NORTH HOLLISTON, PASADENA, CA 91104
6 SMITH MATTHEW W 7757 S. JAMESTOWN AVENUE, TULSA, OK 74136
7 GOSS DONALD C 7749 ST. BERNARD #C, PLAYA DEL REY, CA 90293
PCT International Classification Number A61B 8/08
PCT International Application Number PCT/US2001/32392
PCT International Filing date 2001-10-15
PCT Conventions:
# PCT Application Number Date of Convention Priority Country
1 09/687,128 2000-10-13 U.S.A.