U.S. patent application number 12/236234 was filed with the patent office on 2010-11-04 for stereoscopic x-ray system and method.
Invention is credited to Bassel Kano.
Application Number | 20100278301 12/236234 |
Document ID | / |
Family ID | 39269218 |
Filed Date | 2010-11-04 |
United States Patent
Application |
20100278301 |
Kind Code |
A1 |
Kano; Bassel |
November 4, 2010 |
STEREOSCOPIC X-RAY SYSTEM AND METHOD
Abstract
Disclosed are systems and methods for obtaining stereoscopic
x-ray images. The method includes taking two digital x-ray views of
the same object from differing positions. The included angle
between the axes of the x-rays for each position generally
coincides with that formed by a pair of eyes viewing the object,
though larger angles can be used. The x-rays can be taken by two
x-ray generators within a single housing or within separate but
attached housings. The generators are spaced apart and aimed at the
object to form the appropriate angle. Care is taken not to move the
object. Preferably, the x-ray generators have dual collimators to
take the views. In this case, the time between taking the two
x-rays need only be as long as the image capture time of the sensor
being used, which lessens the chance of the object moving.
Inventors: |
Kano; Bassel; (Boston,
MA) |
Correspondence
Address: |
FOLEY HOAG, LLP;PATENT GROUP, WORLD TRADE CENTER WEST
155 SEAPORT BLVD
BOSTON
MA
02110
US
|
Family ID: |
39269218 |
Appl. No.: |
12/236234 |
Filed: |
September 23, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11539007 |
Oct 5, 2006 |
7440540 |
|
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12236234 |
|
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Current U.S.
Class: |
378/41 |
Current CPC
Class: |
A61B 6/022 20130101 |
Class at
Publication: |
378/41 |
International
Class: |
G21K 4/00 20060101
G21K004/00 |
Claims
1. A method of obtaining a stereoscopic x-ray image of a target,
comprising: energizing a first x-ray tube to emit x-rays in a
direction towards the target; energizing a second x-ray tube spaced
apart from the first x-ray tube to emit x-rays in a direction
towards the target; detecting emitted x-rays at a sensor to obtain
sensor data; processing the sensor data to obtain image data; and
displaying the image data to provide a stereoscopic x-ray image of
the target, wherein the image data does not include information
from prior 3-D images; and wherein the stereoscopic x-ray image of
the target does not include information from prior 3-D images.
2. The method of claim 1, further comprising: connecting to a power
supply; and transforming power from the power supply to provide a
differential voltage at the x-ray tubes sufficient to energize the
x-ray tubes.
3. The method of claim 2, comprising limiting the power from the
power supply to that required for energizing the first and the
second x-ray tubes.
4. The method of claim 1, wherein detecting comprises: downloading
the sensor data obtained by detecting the x-rays emitted from the
first x-ray tube to a processor; and downloading the sensor data
obtained by detecting the x-rays emitted from the second x-ray tube
to the processor.
5. The method of claim 1, further comprising: prior to energizing
the second x-ray tube, cutting power to the first x-ray tube; and
clearing the sensor data obtained by detecting the x-rays emitted
from the first x-ray tube from the sensor.
6. The method of claim 1 wherein displaying comprises filtering the
stereoscopic x-ray image to restrict viewing of a portion of the
stereoscopic x-ray image corresponding to x-rays detected by the
sensor from one of the x-ray tubes to viewing from one eye of a
viewer at a position of the eye with respect to the display
corresponding to a position of the one of the x-ray tubes with
respect to the object.
7. The method of claim 6, wherein filtering comprises restricting
an angle at which light from a pixel of a liquid crystal display
can be viewed.
8. The method of claim 1 wherein displaying comprises: displaying a
first portion of the stereoscopic x-ray image corresponding to
x-rays detected by the sensor from the first x-ray tube to a first
eye of a viewer; and displaying a second portion of the
stereoscopic x-ray image corresponding to x-rays detected by the
sensor from the second x-ray tube to a second eye of the
viewer.
9. The method of claim 1, further comprising maintaining the
positions of the first and second x-ray tubes, the sensor and the
target during energizing and detecting.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The present application claims the benefit of U.S. Utility
patent application Ser. No. 11/539,007, which was filed Oct. 5,
2006, entitled "STEREOSCOPIC X-RAY SYSTEM AND METHOD," by Bassel
Kano, which is hereby incorporated by reference.
FIELD
[0002] The disclosed methods and systems relate to diagnostic
imaging systems, and more specifically to systems and methods for
obtaining stereoscopic x-ray images.
BACKGROUND
[0003] X-ray technology has found many practical uses in medical,
industrial, and scientific fields. One of the more familiar uses of
x-rays is as a diagnostic tool in the fields of medicine and
dentistry. As such, x-rays are used to visualize anatomical
structures and detect the presence of pathology, disease or
abnormal anatomy. Advances in x-ray technology include the use of
digital x-ray equipment, wherein images are captured digitally. The
use of digital x-ray equipment can greatly reduce a patient's
exposure to potentially harmful radiation, while providing sharper
image detail and ease of processing.
[0004] However, the usefulness of x-ray technology has been limited
by the difficulty in providing three-dimensional information of the
object being examined. Studies in the field of dentistry have shown
that for a more accurate diagnosis, two or three radiographs taken
at different angles are necessary. Those radiographs are
conventionally viewed individually by the examiner and processed
and compared in the examiner's brain to be visualized in 3
dimensions.
[0005] Several systems have been devised to obtain three
dimensional information, including transmission X-ray microscopes
and Computerized Axial Tomography (CAT) scanners. These systems
combine x-ray transmission systems with tomographical
reconstruction methods to enable recreation of three-dimensional
information from sets of flat cross-sectional images. The systems
rely on a large number of different cross-sectional images of an
object taken from many different angles. The digital image data is
processed in a computer to yield a three-dimensional picture that
can display the object being examined in great detail.
[0006] The systems, however, are complicated and generally
expensive, making them somewhat inaccessible and unaffordable. In
addition, the amount of the radiation necessary to produce a CAT
image is very high compared to standard two-dimensional images.
What is needed, then, is a system and method for extracting
three-dimensional information from two-dimensional x-ray images
that is relatively simple to use, is accessible and affordable, yet
provides limited exposure of a patient or other object to
radiation.
SUMMARY
[0007] Disclosed are systems and methods for obtaining stereoscopic
x-ray images. The method includes taking two digital x-ray views of
the same object from differing positions. The included angle
between the axes of the x-rays for each position generally
coincides with that formed by a pair of eyes viewing the object,
though larger angles can be used. The x-rays can be taken by two
x-ray generators within a single housing or within separate but
attached housings. The x-ray generators are spaced apart and aimed
at the object to form the appropriate angle. Care is taken not to
move the object. Preferably, the x-ray generators have dual
collimators to take the views. In this case, the time between
taking the two x-rays need only be as long as the image capture
time of the sensor being used, which lessens the chance of the
object moving.
[0008] The digital data from the sensor for each position is
processed in the normal manner to provide an image of the object
from each position. The two resulting images are displayed in a
manner such that only the image corresponding to the viewer's eye
position is received at that eye. Current methods of displaying
three-dimensional (3D) images can be used. For example, the images
can be polarized and viewed through corresponding polarized
eyeglasses. Preferably, the images can be displayed on a 3D liquid
crystal display (LCD) screen, such as the Sharp Actius.TM. RD3D. On
such screens, the two images are overlapped, but use separate
pixels for each image. An LCD filter restricts the angle at which
light from the pixels can be viewed, such that the image
corresponding to the viewer's left eye can only be viewed by the
left eye and vice versa. Other screens are formed with ridges that
restrict the viewing angle for each pixel. Other means for viewing
stereoscopic images include eyeglass video displays that present
the separate images to the corresponding eye, or a 3D viewer using
mirrors to reflect the corresponding image from two monitors to the
respective eye of the viewer.
[0009] In one embodiment, a system for obtaining a stereoscopic
x-ray image of a target includes at least one housing, a pair of
spaced apart x-ray tubes within the at least one housing, each
x-ray tube generating x-rays when energized, a collimator
associated with each x-ray tube and a digital image sensor spaced
opposite the target from the collimators. A longitudinal axis of
each collimator is aligned between its associated x-ray tube and
the target. Each collimator filters the x-rays from its associated
x-ray tube such that x-rays not travelling towards the target are
limited. The digital image sensor detects x-rays from the x-ray
tubes and outputs sensor data for each x-ray tube for forming the
stereoscopic x-ray image. In some aspects, the x-ray tubes may be
located within a single housing.
[0010] In one aspect, the system can include a processor in
communication with the digital image sensor to receive the sensor
data and output image data, and a display in communication with the
processor to receive the image data and output the stereoscopic
x-ray image for viewing. The display can further include a filter
to restrict viewing of a portion of the stereoscopic x-ray image
corresponding to x-rays detected by the sensor from one of the
x-ray tubes to viewing from one eye of a viewer wherein a position
of the eye with respect to the display corresponding to a position
of the one of the x-ray tubes with respect to the object. The
display can be a liquid crystal display and the filter can restrict
an angle at which light from a pixel of the liquid crystal display
can be viewed. The display can be an eyeglass display having a
separate display for each eye of a viewer, wherein each display
presents a portion of the stereoscopic x-ray image corresponding to
x-rays detected at the sensor from one of the x-ray tubes.
[0011] A transformer can convert incoming power to a voltage
differential required to energize the x-ray tubes to emit x-rays. A
power switch can be configured to limit the incoming power. A
transfer switch can be configured to transfer energizing power from
one x-ray tube to the other x-ray tube. A timer can be configured
to activate the transfer switch.
[0012] In one embodiment, a method of obtaining a stereoscopic
x-ray image of a target can include energizing a first x-ray tube
to emit x-rays in a direction towards the target, energizing a
second x-ray tube spaced apart from the first x-ray tube to emit
x-rays in a direction towards the target, detecting emitted x-rays
at a sensor to obtain sensor data, processing the sensor data to
obtain image data and displaying the image data to provide a
stereoscopic x-ray image of the target. In some aspects, the method
can include maintaining the positions of the first and second x-ray
tubes, the sensor and the target during energizing and
detecting.
[0013] The method can include connecting to a power supply and
transforming power from the power supply to provide a differential
voltage at the x-ray tubes sufficient to energize the x-ray tubes.
The method can include limiting the power from the power supply to
that required for energizing the first and the second x-ray
tubes.
[0014] In one aspect, detecting can include downloading the sensor
data obtained by detecting the x-rays emitted from the first x-ray
tube to a processor and downloading the sensor data obtained by
detecting the x-rays emitted from the second x-ray tube to the
processor. Prior to energizing the second x-ray tube, power to the
first x-ray tube may be cut and the sensor data obtained by
detecting the x-rays emitted from the first x-ray tube can be
cleared from the sensor.
[0015] In one aspect, displaying can include filtering the
stereoscopic x-ray image to restrict viewing of a portion of the
stereoscopic x-ray image corresponding to x-rays detected by the
sensor from one of the x-ray tubes to viewing from one eye of a
viewer at a position of the eye with respect to the display
corresponding to a position of the one of the x-ray tubes with
respect to the object. Filtering can include restricting an angle
at which light from a pixel of a liquid crystal display can be
viewed.
[0016] In one aspect, displaying can include displaying a first
portion of the stereoscopic x-ray image corresponding to x-rays
detected by the sensor from the first x-ray tube to a first eye of
a viewer and displaying a second portion of the stereoscopic x-ray
image corresponding to x-rays detected by the sensor from the
second x-ray tube to a second eye of the viewer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic representation of a stereoscopic x-ray
system; and
[0018] FIG. 2 is a block diagram of a method for providing
stereoscopic x-ray images.
DESCRIPTION
[0019] To provide an overall understanding, certain illustrative
embodiments will now be described; however, it will be understood
by one of ordinary skill in the art that the apparatus described
herein can be adapted and modified to provide apparatus for other
suitable applications and that other additions and modifications
can be made without departing from the scope of the systems and
methods described herein.
[0020] Unless otherwise specified, the illustrated embodiments can
be understood as providing exemplary features of varying detail,
and therefore, unless otherwise specified, features, components,
modules, and/or aspects of the illustrations can be otherwise
combined, separated, interchanged, and/or rearranged without
departing from the disclosed systems or methods. Additionally, the
shapes and sizes of components are also exemplary and unless
otherwise specified, can be altered without affecting the disclosed
systems or methods. Throughout the entirety of the present
disclosure, use of the articles "a" or "an" to modify a noun can be
understood to be used for convenience and to include one, or more
than one of the modified noun, unless otherwise specifically
stated.
[0021] FIG. 1 illustrates a schematic representation of a system 10
for producing stereoscopic x-ray images. A transformer 12 within
housing 14 of system 10 is connected to a power supply 3 via power
switch 16. Power switch 16 may be remotely located so as not to
expose an operator to radiation. Transformer 12 converts incoming
power from power supply 3 to provide a high voltage differential
across the electrode pairs (not shown) of x-ray tubes 18a and 18b.
X-ray tubes 18a, 18b operate in the manner of known x-ray tubes to
emit x-rays. For example, current to the cathode of the electrode
pair heats a filament, which sputters electrons to a tungsten anode
at high speed. A high speed electron can knock loose an electron
from a tungsten atom's lower orbital and an electron from a higher
orbital can fall to the lower energy level, releasing a high energy
x-ray photon. Transfer switch 20 can transfer current from x-ray
tube 18a to x-ray tube 18b and vice versa. Switch 20 can include
timer 22 for automatic transfer of current.
[0022] Collimator tubes 24a, 24b absorb unwanted x-rays to
effectively limit the emitted x-rays to a direction along their
longitudinal axes 26a, 26b. In this manner, the emitted x-rays are
filtered so that only those travelling essentially parallel to axes
26a, 26b and generally convergent on target 5 are allowed through
the collimator tubes 24a, 24b. Pure aluminum disks 28a, 28b may be
placed in the path of the x-ray beams to filter out low energy
x-rays whose wave lengths are such that they would not penetrate
the object and hence would not be useful for producing images.
Image sensor 30 digitally captures the x-ray photons passing
through object 5 and the digital sensor data captured by sensor 30
is input to processor 32 (as illustrated by arrow 34). Processor 32
processes the sensor data obtained from each x-ray tube 18a, 18b to
obtain image data for a pair of two-dimensional images 36a, 36b
that are displayed on display 38.
[0023] The two resulting images 36a, 36b are displayed in a manner
such that only the image for the x-ray tube corresponding to the
viewer's eye position is received at that eye, thus providing a 3D
image 36 to the user. Known methods for displaying 3D images may be
utilized. For example, the images can be polarized and/or colored
and viewed through corresponding polarized and/or colored
eyeglasses. Preferably, the images can be displayed on a 3D LCD
screen, such as the Sharp Actius.TM. RD3D. On such screens, the two
images are overlapped, but use separate pixels for each image. An
LCD filter restricts the angle at which light from the pixels can
be viewed, such that the image corresponding to the viewer's left
eye can only be viewed by the left eye and vice versa. Other types
of displays include screens formed with ridges that restrict the
viewing angle for each pixel; eyeglass video displays that present
the separate images to the corresponding eye; 3D viewers using
mirrors to reflect the corresponding image from two monitors to the
respective eye of the viewer; and other means as are known in the
art.
[0024] FIG. 2 is a block diagram of a method 100 by which system 10
provides stereoscopic x-ray images for viewing. X-ray system 10 is
activated (102) using power switch 16. When system 10 is activated,
current flows (104) to transformer 12. Power switch 16 may limit
the amount of current that flows to transformer 12 to that required
for system 10 to obtain the image data for forming the stereoscopic
image. Power switch 16 may work in conjunction with transfer switch
20 and timer 22 to limit the total time of exposure, i.e., the time
during which the object 5 is exposed to x-rays. Transformer 12
converts (106) the incoming power to provide the necessary high
voltage differential across the electrode pairs of a first of the
x-ray tubes 18a, 18b so as to energize (108) the tube. For the sake
of illustration, but not limitation, the systems and methods are
described herein with x-ray tube 18a being the first energized
x-ray tube and x-ray tube 18b being the second energized x-ray
tube. It will be understood that the order in which the x-ray tubes
are energized does not affect the operation of the systems or
methods described.
[0025] When x-ray tube 18a has been energized for a time sufficient
to obtain sensor data at image sensor 28 for forming a digital
image, as determined by timer 22 at block 110, switch 20 is
activated to cut power to x-ray tube 18a, as at block 112. Image
sensor 28 may download (114) the sensor data obtained from x-rays
emanating from x-ray tube 18a to processor 30. After a time
sufficient for image sensor 28 to clear, as determined by timer 22
at block 116, switch 20 is activated (118) such that the output
from transformer 12 is directed to x-ray tube 18b to energize x-ray
tube 18b (120).
[0026] When x-ray tube 18b has been energized for a time sufficient
to obtain sensor data at image sensor 28 for forming a digital
image, as determined by timer 22 at block 122, switch 20 is
activated to cut power to x-ray tube 18b, as at block 124. Timer 22
may operate in conjunction with switch 16 to limit power to
transformer 12, such that when power to x-ray tube 18b is cut,
switch 16 may be activated to cut power to transformer 12, as
indicated by dashed block 126. Switch 16 may independently cut
power to transformer 12 after a preset amount of time as a
fail-safe measure.
[0027] Image sensor 28 may download (128) the sensor data obtained
from x-rays emanating from x-ray tube 18b to processor 30. For
illustration purposes, downloading of the sensor data from image
sensor 28 to processor 30 (blocks 114, 128) is shown following the
cutting of power to x-ray tubes 18a, 18b. However, depending on the
configuration of image sensor 28 and processor 30, image sensor 28
may download the sensor data to processor 30 while x-ray tubes 18a,
18b are energized or both during and after x-ray tubes 18a, 18b are
energized.
[0028] Processor 30 processes (130) the sensor data to obtain image
data corresponding to a two-dimensional x-ray image for x-ray tube
18a and a two-dimensional x-ray image for x-ray tube 18b. The image
data is forwarded (132) to display 36. Using the image data from
processor 30, display 36 displays (134) the image data such that a
viewer perceives a 3D x-ray image of the target, as described with
relation to display 36.
[0029] Although the stereoscopic x-ray system and method have been
described relative to specific embodiments thereof, they are not so
limited. Obviously many modifications and variations may become
apparent in light of the above teachings. For example, timer 22 can
be configured with power switch 16, or separately along power line
40 feeding transformer 12. Alternately, x-ray tubes 24a, 24b may
each be located within a housing that may be attached together to
form housing 14. Similarly, each x-ray tube 24a, 24b may have its
own transformer 12 and transfer switch 20 may be configured with
power switch 16 to transfer power between the transformers 12.
Elements, components, modules, and/or parts thereof that are
described and/or otherwise portrayed through the figures to
communicate with, be associated with, and/or be based on, something
else, can be understood to so communicate, be associated with, and
or be based on in a direct and/or indirect manner, unless otherwise
stipulated herein.
[0030] Many additional changes in the details, materials, and
arrangement of parts, herein described and illustrated, can be made
by those skilled in the art.
* * * * *