U.S. patent application number 12/118310 was filed with the patent office on 2008-10-09 for computed radiography x-ray cassette with rigid embedded cr plate.
Invention is credited to Stephen Neushul.
Application Number | 20080245973 12/118310 |
Document ID | / |
Family ID | 23786483 |
Filed Date | 2008-10-09 |
United States Patent
Application |
20080245973 |
Kind Code |
A1 |
Neushul; Stephen |
October 9, 2008 |
COMPUTED RADIOGRAPHY X-RAY CASSETTE WITH RIGID EMBEDDED CR
PLATE
Abstract
Embodiments include a method and apparatus for improving the
reusability of a computed radiography (CR) plate by housing it in a
cassette. The CR plate remains in the cassette during scanning. The
embodiments of the method and apparatus improve the reusability of
the CR plate.
Inventors: |
Neushul; Stephen; (Redondo
Beach, CA) |
Correspondence
Address: |
BLAKELY SOKOLOFF TAYLOR & ZAFMAN LLP
1279 OAKMEAD PARKWAY
SUNNYVALE
CA
94085-4040
US
|
Family ID: |
23786483 |
Appl. No.: |
12/118310 |
Filed: |
May 9, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10714087 |
Nov 13, 2003 |
7375350 |
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12118310 |
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10386326 |
Mar 10, 2003 |
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10714087 |
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09747616 |
Dec 20, 2000 |
6532092 |
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10386326 |
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09450031 |
Nov 24, 1999 |
6188501 |
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09747616 |
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Current U.S.
Class: |
250/485.1 ;
250/484.4 |
Current CPC
Class: |
G02B 27/023 20130101;
H04N 1/193 20130101; H04N 1/12 20130101; H04N 2201/0418 20130101;
Y10S 359/90 20130101 |
Class at
Publication: |
250/485.1 ;
250/484.4 |
International
Class: |
G01J 1/58 20060101
G01J001/58; H05B 33/00 20060101 H05B033/00 |
Claims
1. A system comprising: a scanning device; and a cassette removably
coupled to the scanning device comprising a housing, a
photostimulatable unit securely coupled to the housing and a cover
movably coupled to the housing to move between a first position
concealing the photostimulatable unit in the housing and a second
position revealing the photostimulatable unit.
2. The system of claim 1, wherein the scanning device comprises an
erasing device.
3. The system of claim 1, wherein the scanning device comprises a
chamber to protect the photostimulatable unit from ambient energy
sources when exposed.
4. The system of claim 2, wherein the photostimulatable unit is a
computed radiography plate.
5. The system of claim 1, wherein the scanning device and cassette
have a complementing interconnection mechanism.
6. A method comprising: revealing a photostimulatable unit to a
scanning device without decoupling the photostimulatable unit from
a cassette; stimulating the photostimulatable unit; scanning the
activated photostimulatable unit; and erasing the photostimulatable
unit.
7. The method of claim 6, further comprising: closing the cassette
to return the photostimulatable unit to a concealed position.
8. The method of claim 6, wherein the photostimulatable unit is a
computed radiography plate.
9. The method of claim 6, further comprising: unlocking a cover of
the cassette.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] The application is a Divisional of patent application Ser.
No. 10/714,087, filed Nov. 13, 2003 entitled, "COMPUTED RADIOGRAPHY
X-RAY CASSETTE WITH RIGID EMBEDDED CR PLATE," which is a
Continuation-In-Part of co-pending patent application Ser. No.
10/386,326, filed Mar. 10, 2003 entitled, "AN APPARATUS AND METHOD
OF CAPTURING IMAGES FROM ALTERNATIVE MEDIA TYPES," which is a
Divisional of Issued U.S. Pat. No. 6,532,092, which is a
Continuation of Issued U.S. Pat. No. 6,188,501.
BACKGROUND
[0002] 1. Field of the Invention
[0003] The embodiments of the invention relate to x-ray cassettes
and computed radiography plates. Specifically, embodiments of the
invention relate to a system for creating images from a plate in a
cassette and erasing the plate with improved reusability of the
plate.
[0004] 2. Background
[0005] Traditional x-ray film has been used for decades. 28 years
ago, a fundamental innovation by Kodak created the first version of
a re-usable X-ray plate instead of film. These Computed Radiography
(CR) plates store a latent image in a photostimulatable storage
phosphor plate. Fuji improved on the Kodak concept and produced the
first medical X-ray images using this technique. The CR plate is
reflective and erasable allowing repeated exposures, the number of
possible exposures is greater than 150,000 if there are no
mechanical stresses on the material. An x-ray impregnates the plate
with energy which, when subsequently exposed to a particular
excitation, is released, recreating the image. Scanners or CR
readers of these plates typically include a flying spot laser and
photomultiplier tube sensor. The photo multiplier tube captures the
image corresponding to the energy being released by excitation of
the flying spot laser. The plate is traditionally removed from a
cassette and transported by a drive mechanism, typically a set of
rollers. This roller type reading process necessitates that the
phosphorescent plate be flexible. The feed mechanism used for
scanning the plates is typically a set of pinch rollers. Over time
the flexing and contact with the rollers causes a deleterious
effect on the plate resulting in limited reusability. The phosphor
materials in the plates do not degrade due to read/write cycles if
mechanical and physical stresses do not act on the plate.
Additional wear and tear on the plate is caused by the removal and
replacement of the plate in a cassette that protects the plate from
ambient energy (light) sources during transportation. In addition
to causing degradation of the quality of the plate the pinch
rollers can slip causing line artifacts and blurring of the image
being generated.
BRIEF DESCRIPTION OF THE DRAWINGS
[0006] Embodiments of the invention are illustrated by way of
example and not by way of limitation in the figures of the
accompanying drawings in which like references indicate similar
elements. It should be noted that different references to "an" or
"one" embodiment in this disclosure are not necessarily to the same
embodiment, and such references mean at least one.
[0007] FIG. 1A is a diagram of a closed cassette.
[0008] FIG. 1B is a diagram of an open cassette.
[0009] FIG. 2 is a side view of a scanning device and cassette with
an exploded view of the coupling mechanism.
[0010] FIG. 3A is a diagram of scanner prior to loading of a
cassette.
[0011] FIG. 3B is a diagram of a scanner with an attached
cassette.
[0012] FIG. 3C is a diagram of a scanner with a secured
cassette.
[0013] FIG. 4 is a diagram of a latching mechanism for a
cassette.
[0014] FIG. 5 is a flowchart of the operation of scanner
operation.
DETAILED DESCRIPTION
[0015] FIG. 1A is a diagram of a closed cassette. In one
embodiment, cassette 101 includes housing 111 to enclose a computed
radiography plate. A computed radiography (CR) plate may be a plate
covered in a phosphor storage material used to capture x-ray
images. In another embodiment, other photostimulatable materials
may be used to construct the CR plate. Housing 111 is constructed
primarily from carbon fiber, aluminum, Delrin plastic and similar
material that protect the CR plate from ambient energy sources.
[0016] In one embodiment, cassette 101 includes a sliding cover 103
or similar mechanism to provide access to an internal cavity of
cassette 111 where the CR plate is embedded. In another embodiment,
other exposure mechanisms may be employed to control access to the
CR plate stored within housing 111. This may include hinged doors,
spring loaded covers, form fit covers, snap fit covers and similar
configurations. The CR plate may be affixed to the sliding or
moving cover. In one embodiment, cassette 101 meets national
emergency medicine association (NEMA) standards for size of x-ray
cassettes.
[0017] In one embodiment, at either end of the cassette may be a
set of steel strips 105, 115. Steel strips 105, 115 may be
magnetized. In another embodiment, other magnetizable materials may
be used. Steel strip 105 may be attached to the housing. Steel
strip 115 may be attached to sliding cover 103. Cover 103 may slide
in a track defined by housing 111 or move in relation to housing
111 by hinge or similar mechanism. In one embodiment, cover may be
removed from cassette 101. Cover 103 may be constructed of carbon
fiber, aluminum, Delrin plastic or similar materials. Steel strips
105, 115 may be used to move or hold cover 103 in relation to
housing 111 in order to open and close cassette 101. Steel strips
105, 115 may include a notch 107. Notch 107 may be used to position
cassette 101 in relation to a scanner. Magnetized protrusions may
be attached to the scanner to interact with the notches 107 to
allow manipulation of the cassette to open and close the cassette.
In another embodiment, physical interconnections between cassette
101 and scanner 301 may be used to move cover 103 in relation to
housing 111.
[0018] In one embodiment, cassette 101 may include an attachment
mechanism 109 along an edge or side of cassette 101. Attachment
mechanism 109 may be a clip, groove to fit a complementary tongue,
hook or similar connection mechanism.
[0019] In one embodiment, cassette 101 may have a label attached to
an outer surface. The label may be a bar code or similar
electronically readable label. The label may be used to identify a
patient, identify characteristics such as size of cassette and
encode similar information.
[0020] FIG. 1B is an illustration of a partially opened cassette.
In one embodiment, cassette 101 encloses a CR plate 113. CR plate
113 may be exposed to a scanner or for other purposes by movement
of housing 111 in relation to cover 103. Cover 103 may be form fit
into a set of tracks in the housing allowing easy movement between
an open and closed position.
[0021] FIG. 2 is a cross section illustration of a securing
mechanism. In one embodiment, cassette 101 may include a securing
mechanism to secure cover 103 in relation to housing 111. In one
embodiment, the securing mechanism may be a latch 201. Latch 201
may be spring loaded or similarly biased into a lock position where
a catch 203 on cover 103 is engaged by latch 201. This prevents the
movement of cover 103 in relation to housing 111. The locked
position provides protection for CR plate 113 during transport. If
cover 103 were to open accidentally then ambient energy sources may
damage the stored image. In one embodiment latch 201 may be
attached to housing 111 near the edge where attachment mechanism
109 is present. Latch 201 may include a protrusion 205 that
protrudes through the exterior of housing 111. Pressure exerted on
protrusion 205 may release latch 201 and allow the movement of
cover 103. In one embodiment, the attachment of cassette 101 to a
scanner automatically disengages latch 201.
[0022] FIGS. 3A-3B illustrate the attachment of a cassette 101 to a
scanner 301. FIG. 3A illustrates an embodiment where a scanner 301
has an open panel 303 for the insertion of cassette 101. Cassette
101 may be loaded through front panel 303. In another embodiment,
scanner 301 does not have a front panel 303. Cassette 101 is placed
adjacent a flat surface of scanner 301.
[0023] FIG. 3B illustrates the initial attachment of cassette 101
using a hook or clip type attachment mechanism 109. In one
embodiment, cassette 101 is attached to scanner 301 using a hook or
clip type attachment mechanism 109. Cassette 101 is angled to
insert the forward protruding section of the hook, clip or similar
device into a receiving groove, hook, slot or similar
mechanism.
[0024] FIG. 3C is an illustration of the final placement of
cassette 101 in scanner 301. In one embodiment, cassette 101 is
laid flat against a surface of scanner 301. Cassette 101 may be
coupled in a removable manner to scanner 301. The coupling
mechanism may be a complementary hook, slot, groove, clip or
similar system. In another embodiment, cassette 101 is form fit or
set in a track in scanner 301. Scanner 301 may include a sliding or
hinged door 305 to panel 303 that may completely enclose cassette
101.
[0025] In one embodiment, scanner 301 may move cassette 101 in a
lateral or horizontal direction across the surface of scanner 301.
Scanner 301 may include a scanning head such as a photo multiplier
or charged coupled device (CCD) to capture the image of CR plate
113 as it is moves past the head. A set of magnets in scanner 301
may exert force on steel strips 105, 115 to move housing 111 while
holding cover 103 in place thereby to expose CR plate 113 to the
scanner head. In one embodiment, the magnets utilized in scanner
301 have a complementary polarity to magnetized steel strips 105,
115. In another embodiment, CR plate 113 may be attached to cover
103 and cover 103 moved past scanner 301. In a further embodiment,
alternative movement mechanisms may be used to move housing 111 and
cover 103. The movement mechanism may physically grip either cover
103 or housing 111 to move each component in relation to the other
and to the scan head. Other movement mechanisms may include
rollers, moving tracks, belts and similar mechanisms. Scanner 301
may also include a laser, set of light emitting diodes (LED) or
similar energy source to erase CR plate 113.
[0026] In one embodiment, scanner 301 has a flat scan path to
enable the reading of labels on cassette 101. Scanner 301 may
include a label reader such as a bar code scanner. Scanner 301 may
obtain information about a patient or the content of the x-ray
being scanned or may obtain information about the characteristics
of cassette 101 from the label. Scanner 301 may utilize the
information obtained from the label to adjust the manner in which
cassette 101 is scanned such as adjusting the length or speed of
the scan or making similar adjustments. In one embodiment, data
read from the label may influence handling of the digital
representation captured by scanner 301. For example, label content
may indicate where in memory or the file system of the host
computer the digital representation is stored.
[0027] FIG. 4 is a side view illustration of a non-enclosing
scanner with and exploded view of an attachment mechanism. In one
embodiment, attachment mechanism 109 may be a clip with a
complementary slide clip 401 attached to scanner 301. Cassette 101
may rest against the front surface of scanner 301. Clip 109 may be
nestled into an interlocking position with slide clip 401. Slide
clip 401 may run the full length of cassette 101 and clip 109.
Slide clip 401 may slide laterally or horizontally in a track or
similar mechanism to allow the movement of cassette 101 past a scan
head and erasure mechanism. Attachment mechanism 109 interlocked
with slide clip 401 or similar mechanism may form an ultra rigid
scan substrate for CR plate 113 to be scanned by scanner 301. In an
exemplary embodiment, cassette 101 may have a clip type attachment
mechanism 109 along the length of an upper edge. Cassette 101 may
be placed at an angle to a complementary slide clip 401 on scanner
301. In this position the protruding edges of the complementary
clips may rest against one another. A slight rotation of cassette
101 toward scanner 301 brings the complementary clips into an
interlocking position and cassette 101 may rest flatly against
scanner 301. A lateral force pushing or pulling cassette 101 away
from scanner 301 may cause the clip of cassette 101 to disengage
from slide clip 401.
[0028] In one embodiment, the secure attachment of cassette 101 to
scanner 301 enables an ultra high resolution scan process where
cassette 101 is driven past a scan head to obtain high fidelity.
Thus, the scan resolution is not diminished by the slipping of
pinch rollers. The system completes a scan of CR plate 113 without
touching CR plate 113. This results in a scanning process that
reduces wear on the photostimulatable material, enhances the
lifetime of CR plate 113 and improves the reading of CR plate 113
during scanning. Scan and erase may take place simultaneously with
the erase following the scan on the same cassette 101. This
increases the throughput for the scanning system. This system may
scan a CR plate 113 on average at a rate of better than twenty five
seconds for a fourteen inch by seventeen inch plate.
[0029] In one embodiment, cassette 101 may have a concave inner
surface or shape to define a concave space for CR plate 113. CR
plate may have a matching concave shape. The concavity of CR plate
113 allows the scanning process and x-ray process to occur on a
curved surface. The curve of the plate may match the spread of
x-ray energy and the sweep of a scanning laser. The curve of CR
plate 113 may be matched to the scanning laser to allow the
operation of the scanner without the use of an F theta lens. F
theta lenses have a high cost and a scanner 301 that does not
require an F theta lens may have a reduced cost to manufacture.
Scanning may be done under this circumstance without losing
fidelity in the scanning process. The laser spot size will change
as the laser scans from top to bottom along a flat surface. The
spot may remain constant in size if the focal distance of the laser
is maintained at a constant by curving CR plate 113 inside of
cassette 113.
[0030] FIG. 5 is a flowchart of the operation of a scanning device
utilizing cassettes 101. In one embodiment, cassette 101 must be
loaded into scanner 301 (block 501). Loading cassette 101 into
scanner 301 may automatically unlock cassette 101 via latch 201 or
similar securing mechanism. In one embodiment, loading cassette 101
involves engaging complementary attachment mechanisms of cassette
101 and scanner 101. Cassette 101 may have an attachment mechanism
109 such as a clip, hook, or similar attachment mechanism. Scanner
301 may have a complementary clip 401, hook, latch or similar
attachment mechanism.
[0031] In one embodiment, scanner 301 may start to move cassette
101 via magnetic force, motorized movement of sliding clip 401 or
similar movement mechanism while cover 103 is held in position by a
magnetic force, latch or similar restraint thereby exposing CR
plate 113 to scanner 301 (block 503). In an exemplary embodiment,
cassette 101 may be attached to sliding clip 401. Sliding clip 401
may be attached to a track to allow it to slide across the surface
of scanner 301. In one embodiment, the length of the slide track is
approximately equal to twice the size of a cassette to allow a
slide to completely expose CR plate 113 by sliding cassette 101
away from cover 103. Movement of sliding clip 401 in the track may
be effected by an electric motor or similar mechanism. In one
embodiment, scanner 301 may stimulate the phosphorous material of
CR plate 113 using a flying spot laser or similar device while
cassette 101 slides across the surface of scanner 301 (block 505).
Scanner 301 continues to move CR plate 113 past a scanner head such
as a photo multiplier or CCD to image the CR plate 113 (block
507).
[0032] In one embodiment, after CR plate 113 or a section of CR
plate 113 has been imaged, scanner 301 may erase the plate or
section using an LED or similar device (block 509). After the
erasure and scan, scanner 301 may return cassette 101 to a closed
position by sliding clip 401 back to its start position on the
scanner track before allowing it to be unloaded (block 511). When
cassette 101 is removed the locking mechanism may be engaged
preventing accidental exposure during transport.
[0033] Cassette 101 may improve the reusability of a CR plate 113
by protecting CR plate 113 throughout its use. CR plate 113 remains
encased in cassette 101 during x-ray capture, scan, erase and
further reuse of CR plate 113. Cassette 101 prevents wear and tear
on CR plate 113 that may cause it to degrade. For example, cassette
101 may be used when a patient has an x-ray taken without removing
CR plate 113 from cassette 101. Cassette 101 may then be safely
transported to scanner 301 where it is imaged and erased and made
ready for reuse without CR plate 113 making any physical contact
with scanner 301 or users. In one embodiment, scanner 301 may be
part of a hybrid direct radiology solution. A patient may stand in
front of an embedded CR plate in a cassette while in an enclosure
where the plate receives the x-rays and scanner 301 reads and
erases CR plate 113. Two cassettes may be rotated into scanner 301
to maintain one CR plate 113 in position for x-rays.
[0034] In the foregoing specification, the invention has been
described with reference to specific embodiments thereof. It will,
however, be evident that various modifications and changes can be
made thereto without departing from the broader spirit and scope of
the invention as set forth in the appended claims. The
specification and drawings are, accordingly, to be regarded in an
illustrative rather than a restrictive sense.
* * * * *