U.S. patent application number 12/080644 was filed with the patent office on 2008-08-14 for dielectric profile controlled microwave sterilization system.
This patent application is currently assigned to Frontier Engineering LLC. Invention is credited to David R. Wilson.
Application Number | 20080190913 12/080644 |
Document ID | / |
Family ID | 37766520 |
Filed Date | 2008-08-14 |
United States Patent
Application |
20080190913 |
Kind Code |
A1 |
Wilson; David R. |
August 14, 2008 |
Dielectric profile controlled microwave sterilization system
Abstract
A dielectric profiler establishes a dielectric profile of
microwave characteristics for identifying, sterilizing or
inactivating a target material prior to performing a microwave
irradiation event to sterilize or inactivate the target
material.
Inventors: |
Wilson; David R.;
(Platteville, CO) |
Correspondence
Address: |
CR MILES, P.C.;CRAIG R. MILES
405 MASON COURT, SUITE 119
FORT COLLINS
CO
80524
US
|
Assignee: |
Frontier Engineering LLC
|
Family ID: |
37766520 |
Appl. No.: |
12/080644 |
Filed: |
April 4, 2008 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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11437399 |
May 18, 2006 |
7354504 |
|
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12080644 |
|
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|
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60682497 |
May 18, 2005 |
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Current U.S.
Class: |
219/679 |
Current CPC
Class: |
A61L 2/24 20130101; A61L
2/0011 20130101; A61L 2/12 20130101; H05B 6/72 20130101; H05B 6/80
20130101; H05B 2206/045 20130101; H05B 6/705 20130101 |
Class at
Publication: |
219/679 |
International
Class: |
H05B 6/64 20060101
H05B006/64 |
Claims
1. A method of irradiating a target material, comprising the steps
of: a. performing a first profiling event of said target material;
b. generating a first dielectric profile of said target material
based on said first profiling event; c. generating a target
material irradiation profile of said target material based on said
first dielectric profile; and d. irradiating said target material
with an amount of microwave radiation based on said target material
irradiation profile.
2. A method of irradiating a target material as described in claim
1, further comprising the step of performing a second profiling
event of said target material subsequent to irradiating said target
material.
3. A method of irradiating a target material as described in claim
2, further comprising the step of generating a second dielectric
profile of said target material based on said second profiling
event.
4. A method of irradiating a target material as described in claim
3, further comprising the step of comparing said second dielectric
profile said target material to said first dielectric profile of
said target.
5. A method of irradiating a target material as described in claim
4, further comprising the step of assessing alteration of said
target material based on comparison of said second target material
irradiation profile to said first target material irradiation
profile.
6. A method of irradiating a target material as described in claim
5, further comprising the step of establishing sufficiency of
alteration of said target material based on comparison of said
second target material irradiation profile to said first target
material irradiation profile.
7. A method of irradiating a target material as described in claim
5, further comprising the steps of; a. establishing insufficiency
of alternation of said target material based on comparison of said
second target material irradiation profile to said first target
material irradiation profile; and b. repeating said step of
irradiating said target material with an amount of microwave
radiation based on said target material irradiation profile to
achieve said step of establishing sufficiency of alteration of said
target material based on comparison of said second target material
irradiation profile to said first target material irradiation
profile.
8. A method of irradiating a target material as described in claim
1, wherein said step of performing said first profiling event
comprises the steps of: a. generating a plurality of frequencies of
microwave radiation which correspond to a swept microwave frequency
spectrum; b. exposing said target material to said plurality of
frequencies of microwave radiation which correspond to said swept
microwave frequency spectrum; and c. detecting adsorption by said
target material of each one of said plurality of frequencies of
microwave radiation which correspond to said swept microwave
frequency spectrum
9. A method of irradiating a target material as described in claim
1, wherein said step of generating a first dielectric profile of
said target material comprises the step of generating a measure of
adsorption by said target material of each one of said plurality of
frequencies of microwave radiation which correspond to said swept
microwave frequency spectrum.
10. A method of irradiating a target material as described in claim
1, wherein said step of generating a target material irradiation
profile of said target material based on said first profiling event
comprises the step of identifying each one of said plurality of
frequencies of microwave radiation which correspond to said swept
microwave frequency spectrum absorbed by said target material.
11. A method of irradiating a target material as described in claim
10, wherein said step of generating a target material irradiation
profile of said target material based on said first profiling event
further comprises the step of establishing a power value of each
one of said plurality of frequencies of microwave radiation which
correspond to said swept microwave frequency spectrum identified as
absorbed by said target material.
12. A method of irradiating a target material as described in claim
10, wherein said step of generating a target material irradiation
profile of said target material based on said first profiling event
further comprises establishing a duration value of each one of said
plurality of frequencies of microwave radiation which correspond to
said swept microwave frequency spectrum identified as absorbed by
said target material.
13. A method of irradiating a target material as described in claim
1, wherein said step of irradiating said target material with an
amount of microwave radiation based on said target material
irradiation profile further comprises the step of: a. adjusting
each one of said plurality of frequencies of microwave radiation
which correspond to said swept microwave frequency spectrum
identified as absorbed by said target material to; b. adjusting a
duration of each one of said plurality of frequencies of microwave
radiation which correspond to said swept microwave frequency
spectrum identified as absorbed by said target material; c.
irradiating said target material with at least one of said
plurality of frequencies of microwave radiation which correspond to
said swept microwave frequency spectrum identified as absorbed by
said target material at said power and for said duration of
time.
14. A method of irradiating a target material as described in claim
2, wherein said step of performing said second profiling event
comprises the steps of: a. generating said plurality of frequencies
of microwave radiation which correspond to a swept microwave
frequency spectrum; b. exposing said target material to said
plurality of frequencies of microwave radiation which correspond to
said swept microwave frequency spectrum; and c. detecting
adsorption by said target material of each one of said plurality of
frequencies of microwave radiation which correspond to said swept
microwave frequency spectrum
15. A method of irradiating a target material as described in claim
3, wherein said step of generating a second dielectric profile of
said target material comprises the step of generating said measure
of adsorption by said target material of each one of said plurality
of frequencies which correspond to said swept microwave frequency
spectrum.
16. A method of identifying a target material, comprising the steps
of: a. performing a profiling event on each one of a plurality of
standard materials; b. generating a standard material dielectric
profile corresponding to each one of said plurality of standard
materials; c. performing said profiling event on a target material;
d. generating a target material dielectric profile corresponding to
said target material; e. comparing said target material dielectric
profile to said standard material dielectric profile generated for
each one of said plurality of standard materials; and f. matching
said target material dielectric profile to said standard material
dielectric profile of one of said plurality of standard materials
to identify said target material.
17. A method of identifying a target material as described by claim
16, wherein said step of performing said profiling event comprises
the steps of: a. generating a plurality of frequencies of microwave
radiation which correspond to a swept microwave frequency spectrum;
b. exposing said target material to said plurality of frequencies
of microwave radiation which correspond to said swept microwave
frequency spectrum; and c. detecting adsorption by said target
material of each one of said plurality of frequencies of microwave
radiation which correspond to said swept microwave frequency
spectrum
18. A method of identifying a target material as described in claim
16, wherein said steps of generating a standard material dielectric
profile corresponding to each one of said plurality of standard
materials and of generating a target material dielectric profile
corresponding to said target material comprise generating a measure
of adsorption for each of said standard material and said target
material of each one of a plurality of frequencies of microwave
radiation which correspond to a swept microwave frequency
spectrum.
19. A target material irradiator, comprising: a. at least one
microwave source which emits a plurality of frequencies of
microwave radiation which correspond to a swept microwave frequency
spectrum at a first power level in a first time duration; b. a
target material exposed to said plurality of frequencies of
microwave radiation which correspond to said swept microwave
frequency spectrum at said first power level in said first time
duration; c. at least one microwave detector which generates a
signal which varies based on adsorption by said target material of
each one of said plurality of frequencies of microwave radiation
which correspond to said swept microwave frequency spectrum at said
first power level in said first time duration; d. a dielectric
profiler which measures adsorption by said target material of each
one of said plurality of frequencies which correspond to said swept
microwave frequency spectrum at said first power level in said
first time duration; e. a target material irradiation profiler
which identifies each one of said plurality of frequencies of
microwave radiation which correspond to said swept microwave
frequency spectrum absorbed by said target material at said first
power level in said first time duration, and wherein said target
irradiation profiler further establishes a power value of each one
of said plurality of frequencies of microwave radiation which
correspond to said swept microwave frequency spectrum identified as
absorbed by said target material at said first power level in said
first time duration, and wherein said target irradiation profiler
further establishes a time duration value of each one of said
plurality of frequencies of microwave radiation which correspond to
said swept microwave frequency spectrum identified as absorbed by
said target material a said first power in said first time
duration; and f. a microwave irradiator which irradiates said
target material with at least one of said plurality of frequencies
of microwave radiation which correspond to said swept microwave
frequency spectrum identified as absorbed by said target material
at said first power level in said first duration of time, wherein
said microwave irradiator emits said at least one of said plurality
of frequencies of microwave radiation at a second power level which
corresponds to said established power value, and wherein said
microwave irradiator emits said at least one of said plurality of
frequencies of microwave radiation in a second time duration which
corresponds to said established time duration value.
20. A target material irradiator as described in claim 19, where
said at least one microwave source couples to a first one half of a
duplex cell, and wherein said at least one microwave detector
couples to a second one half of said duplex cell.
Description
[0001] This United States Non-provisional patent application claims
the benefit of U.S. Provisional Patent Application No. 60/682,497,
filed May 18, 2005, hereby incorporated by reference herein.
I. BACKGROUND
[0002] Microwave radiation has been used to heat a wide variety of
materials to the point where temperatures are sufficient to create
sterilization effects. Many materials, especially those which have
not absorbed moisture, may require prolonged exposure at high power
levels to ensure complete sterilization.
[0003] However, the determination of when a material is rendered
inactive or destroyed by irradiation with microwaves still relies
largely upon observable changes of the irradiated material. This
reliance upon observation of the irradiated material may be
impractical when the irradiated material is divided among a large
number of discrete containers or when the irradiated material is a
biological pathogen or toxic chemical, or may be unlawful for
example in the case of opening the United States mail to obtain
samples of the irradiated material.
[0004] Moreover, conventional irradiation devices and irradiation
methods suffer from a lack of precision. Conventional material
irradiation devices and methods rely upon a fixed frequency
microwave source which provides a high intensity, non-specific
radiation field that may be many times stronger than is required to
sterilize or heat a particular material because determination as to
when a material has been rendered inactive remains largely a matter
of guesswork in many cases.
[0005] As to these problems and other problems related with
conventional microwave irradiation of materials for the purpose of
sterilization or heating of a material, rendering the material
inactive or destroying the material, the instant invention
addresses each in practical fashion.
II. SUMMARY OF THE INVENTION
[0006] Accordingly, a broad object of the invention can be to
provide a dielectric profiler which analyzes the dialect profile of
a material over a wide frequency range which allows adjustment of
the microwave frequency prior to material irradiation to achieve
sterilization or heating.
[0007] Another broad object of the invention can be to provide a
computer which operates a dielectric profiler application program
which compensates for a numerous and wide variety of material
variables including without limitation moisture, volume,
temperature, density, contaminants, or the like, by use of
calibration profiles retrievable from a computer memory
element.
[0008] Another broad object of the invention can be to operate a
dielectric profiler at power levels which avoid or reduce
alteration of the target material (the "profiling event") prior to
irradiation for the purpose of sterilization or heating. Many
substances display an altered irradiation absorption profile once
they have been exposed to any intense radio frequency field. In
certain instances, the amount of microwave energy a material can
absorb can be altered by increasing wavelength frequency of
microwave irradiation. As such, application of a strong irradiation
field at one frequency can alter material characteristics and
hinder measurement of the dielectric characteristics of the
material at a different frequency.
[0009] Another broad object of the invention can be to provide a
method of microwave irradiation of a material which includes at
least a first step of assessing the dielectric profile of a
material to determine a frequency (or frequencies) at which to
irradiate the material, and can include additional steps of
assessing rate of change in temperature of the material at such
established frequency (or frequencies) to establish a duration of
an irradiation period at such frequency (or frequencies),
irradiation of the material at such frequency (or frequencies) for
such irradiation period (the "irradiation event"), comparison of
the dielectric profile of the material before the irradiation event
and the dielectric profile after the irradiation event, assessment
based upon such comparison as to the degree to which the material
has been altered by the irradiation event, and assessment based
upon such comparison as to whether any undesired products have been
generated by the irradiation event.
[0010] Another broad object of the invention can be to provide
automatic detection and selective destruction or inactivation of a
first material on the surface of a second material such as a
manufacturing material; or of a first material contained inside a
space defined by the configuration of a second material such as
parcels, envelopes, boxes, containers, or the like; or of a first
material such as mold or other pathogen located in the wall space
of a building. However, these specific examples are not intended to
be limiting with respect to the numerous and wide variety of
applications encompassed by the invention.
[0011] Another broad object of the invention can be to provide for
detection and identification of concealed materials such as
bacteria, viruses, pathogens, cells, cell components, chemicals,
compositions, or mixtures or combinations thereof, which as to
certain embodiments of the invention, can further comprise the
generation of 3D images of a concealed materials.
[0012] Naturally, further objects of the invention can be
understood from the description and drawings.
III. A BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 shows an embodiment of the invention which operates
to provide both a profiling event and a microwave irradiation event
of a target material.
[0014] FIG. 2 provides non-limiting examples of configurations of
microwave cells and arrays of microwave cells which can be used in
embodiments of the invention to provide a profiling event or a
microwave irradiation event of a target material.
[0015] FIG. 3 shows a particular embodiment of the invention used
to provide a profiling event or an irradiation event, or both, of a
target material such as a letter or package.
IV. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0016] A device and method of using microwaves to irradiate target
material(s) which allows pre-selection of microwave characteristics
to limit duration of the irradiation event, assess alteration of
the material due to the irradiation event, and to detect undesired
products generated by the irradiation event.
[0017] The term "target material" is intended to broadly encompass
any manner of composition regardless of form or configuration which
absorbs microwave radiation and with limitation animal tissue,
plant tissue, biological particles such as bacteria, viruses,
cells, cancer cells, tumors, inorganic materials which in certain
cases may be rare, exotic, or precious materials such as gold,
diamonds, or like or because the material is obtainable only in
small quantity.
[0018] The term "microwave characteristic" is intended to broadly
encompass any microwave frequency or combination of microwave
frequencies, the power or power profile of such microwave frequency
or combination of frequencies, the period or the periods in which
microwave irradiation occurs whether continuous or discontinuous,
or the like.
[0019] The term "sterilization" is intended to broadly encompass
any alteration of the target material including without limitation
killing or inactivating bacteria, viruses, pathogens molds, cells
or components thereof, or inactivating or altering chemicals,
toxins or the like; or increasing the temperature of a target
material to a desired temperature.
[0020] Now referring primarily to FIG. 1, embodiments of the
invention can generate a profile of the microwave characteristics
of a target material(s) of interest. The profile of the microwave
characteristics of the target material can be generated by the
invention by use of a dielectric profiler which measures the amount
of energy absorbed by the target material as a microwave frequency
is swept across a microwave spectrum (the "profiling event").
Variations in the harmonics and the ratio between the fundamental
wave frequency and harmonics are detected and assessed to generate
a target material irradiation profile. The material irradiation
profile can be used to control microwave characteristics applied to
the target material to achieve a level of microwave absorption over
a duration of time (the "irradiation event"). A first material
irradiation profile of a material can be stored in a memory element
and compared against a second material irradiation profile of the
material to assess alteration of the material due to the
irradiation event.
[0021] A computer (22) and associated software provides logistical
and safety control of the various components or element of the
invention. An interface (23) provides manual control(s), input
control(s) and output control(s). A target material conveyer (1)
can transport the target material (2) along the travel path of the
invention. The target material (2) may be moved back and forth
along the travel path by reversing the target material conveyer
(1). The target material (2) can be located between at least one
matrix array panel (26, 29) for the profiling event and a second
matrix array panel (19, 20) for the irradiation event. The number
of matrix panels utilized for the profiling event or the
irradiation event, or both, may be tailored to suit the particular
application.
[0022] A microwave generator (17)(variable frequency or otherwise)
and a series of multiplexors (12, 14, 18, 21, 25, 30) can be
connected to corresponding oscillators (15, 31) and detectors (11,
24) to provide a focused matrix array panel. Each element of the
matrix array panel pair (26, 29 or 19, 20) can be connected to the
corresponding multiplexor (12, 14, 18, 21, 25, and 30) by a network
of microwave transmission lines or circuits (13). Infrared sensors,
humidity sensors, or other sensors (21) can be coupled to the
matrix array panel (20) to provide feedback on temperature rise. A
safety module (16) provides protection against overloads.
[0023] The dielectric profiler can comprise a radiofrequency source
(15 or 31) and a corresponding opposed radiofrequency detector (11
or 24) which can be calibrated over a wide frequency range. The
calibration procedure encompasses each cell of a transmission
element (19 or 29) and each corresponding cell of a receiver
element (20 or 26) of the each matrix array panel used to during
the profiling event associated with the target material (2). The
component parts above-described, define the "radiofrequency
network" of the invention.
[0024] Calibration of the radiofrequency network comprises the
steps of using the computer (22) to locate the transmission
element(s) (19 or 29) and the corresponding receiver elements (20
or 26) a distance apart according to an operators input (if the
system is set for manual mode) or from sensors (32) if the system
is in automatic mode. The target material (2) used for calibration
can be located between the transmission element-receiver element
pairs. The transmission element-receiver element pairs as shown by
FIGS. 1, 2, 3 can be vertically oriented but as to certain
embodiments of the invention the transmission element-receiver
element pairs can be oriented horizontally or at other angles
depending on the application. It is also possible for two
transmission element-receiver element pairs to be mounted to form a
square, or other geometric configuration, for use in processing all
the surfaces of a target material (2) in one operation.
[0025] The computer (22) can adjust the oscillator of each
radiofrequency source ("RF source") (15, 31) to a first frequency
"x" and connects the output of the RF source (15, 31) through the
selector (18, 30) to the matrix array panel (19, 29) to transmit
cell "A". The output of the receiver cell "Ar" opposing the
transmit cell "A" can be connected through the selector (12, 25) to
the radiofrequency detector "RF detector" (11, 24). The analog
output of the receiving cell "Ar" is proportional to the intensity
of the radiofrequency field received from the transmit cell "A".
The analog signal of receiver cell "Ar" can be converted into a
digital signal retrievably storable in a memory element of the
computer (22).
[0026] The computer as to transmission cell "A" and receiver cell
"Ar" can adjust the oscillator of each RF source (15, 31) to a
second frequency "y" and the sequence of steps above-described can
be repeated. Once a plurality of frequencies in the frequency range
have been applied to the target material calibrated for the
transmission cell "A" and receiver cell "Ar", as above-described,
the computer calibrates a second transmission cell-receiver cell
pair by the above-described steps. The steps in the sequence are
repeated until all the transmission cell-receiver cell pairs in the
matrix array panel (19, 20 or 29, 26) are calibrated.
[0027] Each transmission cell or receiver cell within a matrix
array panel pair may itself be comprised of a number of "elements"
to allow for a wide variety of target material configurations
whether size or shape variations. Each element can undergo a
similar sequence of calibration cycles.
[0028] Upon completion of the calibration procedure the computer
(22) now has a "map" of the field intensity related the plurality
of transmission cell-receiver cell pairs or plurality of element
pairs within the matrix array panel or portion thereof utilized in
the calibration event. The result of the calibration event is that
substantially all of the radio frequency variables are "calibrated
out" of the response of the radiofrequency network over the
calibration frequency range. When a target material (2) is located
between the cell pairs or element pairs of a calibrated matrix
array panel pair (29, 26 or 19, 20), the signal from the
corresponding detector (11 or 24) reflects the alteration of the
microwave energy absorbed due to the dielectric characteristics of
the target material (2) to which the dielectric profiling event was
applied.
[0029] As the target material (2) is subjected to a dielectric
profiling event, changes within the target material (2) can affect
the relative amplitude of the harmonics of the fundamental
frequency. Some harmonics may increase while others may decrease.
These alterations in harmonics of the fundamental frequency form
part of the dielectric profiling data gathered along with other
dielectric profiling data such as exposure time, temperature, field
intensity, or the like. The dielectric profiling data can be stored
in the memory element of the computer (22) and can be used to
generate a dielectric profile of the target material (2) which can
be utilized to identify the target material (2) by comparison to
dielectric profiles of target materials used as standards and can
be further utilized as the basis for prescribing the microwave
characteristics of the microwave irradiation event.
[0030] The dielectric profiling event for a target material (2) can
be carried by repeating the steps of the calibration event
above-described. Dielectric profiling event values can be
mathematically manipulated to correct for all of the variables of
the original calibration event. The results can be stored as the
"dielectric profile" of the target material (2). The dielectric
profile is a measure of the target material's absorption of the
different frequencies within the microwave frequency spectrum
applied during the dielectric profiling event. The frequency or
frequencies that the target material absorbs most represents the
frequency or frequencies to which the target material is most
sensitive.
[0031] Once the dielectric profile for the target material (2) has
been stored in the memory element of the computer (22) a map can be
generated showing which frequency or frequencies are associated
with energy absorption for that particular target material. As
such, a plurality of dielectric profiles can be used as standard
dielectric profiles to identify the corresponding target material
in applications such as screening mail or baggage. The dielectric
profile can also be used in conjunction with an application program
to control the frequency and output power of a microwave generator
(17) for subsequent microwave irradiation events.
[0032] If the target material (2) undergoes the microwave
irradiation event utilizing the frequency and output power
established by use of the dielectric profile in conjunction with
the application program, alteration of the target material (2) due
to the microwave irradiation event can be assessed by comparison of
a first dielectric profile of the target material generated before
the microwave irradiation event and second dielectric profile of
the target material generated after the microwave irradiation
event.
[0033] The computer (22) can be programmed to automatically select
the appropriate field strength and duration of exposure(s) for any
target material (2) identified by the dielectric profiler. Software
may be used to manipulate the stored values to suit the particular
application, for example it may be desirable to extend exposure
time if a temperature or humidity change in the immediate
environment surrounding the sample were to occur. In the embodiment
of the invention shown by FIG. 1 there are two dielectric
profilers; the first comprises elements 11, 12, 13, 33, 32, 14 and
15. The second comprises elements 24, 25, 26, 29, 30 and 31. The
duplication of the dielectric profiler and the profiling event and
the associated circuitry and computer application program can
increase throughput and accuracy in an environment in which a large
number discrete targets require assessment. It can avoid the need
to reverse the target material conveyor (1) to re-appraise the
target material (2) after the microwave irradiation event. The
basic configuration of the embodiment of the invention shown by
FIG. 1 may be repeated if increased speed, accuracy or throughput
is required. The system could be a continuum of dielectric profiler
1, generator 1, dielectric profiler 2, generator 2, dielectric
profiler 3 and so forth. The invention is normally operated under
computer (22) control but a manual interface (23) is provided to
allow local control of the invention if required.
[0034] Now referring primarily to FIGS. 2 and 3, a matrix of
microwave antenna cells (7, 9) can be formed into a microwave
transmission array (3) large enough to provide >100% coverage of
the target material (2) to be examined or evaluated. Each
transmission cell can be connected in turn to the microwave
generator (17) through a multiplexer (14) (as shown by FIG. 1). The
dwell time (the length of time each transmission cell stays
connected to the microwave generator) is determined by the computer
(22) which also controls the speed at which the target material (2)
passes in front of the microwave transmission array (3).
[0035] Now referring specifically to FIG. 2, an embodiment of the
microwave transmission array (3) can comprise a plurality of
microwave antenna cells (7, 8 or 9) formed into a matrix (3, 4, 5,
6) which may be configured to optimize performance in the frequency
bands of interest or accommodate the size and shape of the target
material (2) to provide the optimum depth of field or provide a
uniform intensity field, or both, for use in profiling events to
detect and identify target materials. These attributes conserve
power by focusing the energy; applying the optimum energy field
strength over the desired area and minimizing collateral damage to
surrounding objects or substances. There are many variations and
permutations available in existing microwave antenna technology
that can provide the desired matrix cell, aperture and gain. By
combining numerous individual transmission elements (such as 10)
with a parabolic reflector (7), or an alternative reflector (9) of
less focal capability but perhaps wider bandwidth, an array with
the desired beam width, bandwidth and gain may be produced.
[0036] The microwave energy (to or from) the individual cells
within the overall matrix may be electronically manipulated to
provide a series of macro-cells which allows a lower or higher
resolution to be achieved. For example the matrix shown in FIG. 3
can be comprised of 36 cells in a 6.times.6 format. Each cell may
be used individually or the energy from 2.times.2 or 3.times.3 or
4.times.4 or 2.times.4, or the like, can be combined to produce a
desired distribution of microwave energy. Any permutation is
possible within the constraints of normal microwave engineering
problems such as insertion loss, bandwidth, reduced signal to noise
ratio and the like. The individual transmission elements (10)
within a transmission cell can also be configured as antennas with
specified beam width and directivity. Individual cells (7, 9) may
be "nested` to form a compound structure designed to achieve a
specified bandwidth or other desirable characteristic. High and low
frequency cells may be interleaved to achieve a specified bandwidth
or other desirable characteristic. A matrix may be composed of as
many cells as is desired, a practical limit will be set
automatically by physical constraints or microwave engineering
limitations.
[0037] For analysis of a small target material (2) or for analyzing
small amounts of a target material (2), an individual "duplex cell"
(7 and 8) can be used. Typically, one half of the cell could have a
concave surface (7), the other a convex surface (8). Regardless of
the surface profile actually used, both parts of the cell must mate
together accurately. Membranes or coatings of inert material can be
used to electrically isolate the surfaces of the transmission cell
from the target material (2). Conductive bands, strips or arrays of
elements (such as, but not limited to, dipoles) of conductive
material, may be configured into the cell structure to provide the
desired energy distribution profile. The cells can be moved by
actuating mechanisms, such as but not limited to motors or
piezoelectric crystals. Cells may be brought into close proximity
under computer or manual control. Cells may be mounted in a sealed
chamber for security, safety or other considerations such as
cryogenic temperature analysis etc. Cells, especially those used
for dangerous substance analysis or where cross contamination is a
concern could be designed and manufactured to be disposable. The
matrix assemblies can be moved by actuating mechanisms, such as but
not limited to motors, air pistons, hydraulic rams etc. Matched
pairs of matrix assemblies may be brought into close proximity
under computer or manual control. Matched pairs of matrix
assemblies may be mounted in a sealed chamber for security, safety
or other considerations such as cryogenic temperature analysis, or
the like. A version of the matrix assembly can be designed and
manufactured to be disposable. Cells or matrix assemblies may be
fitted with an integrated tracking device for security purposes.
Cells or matrix assemblies may be fitted with an auto destruct
mechanism to protect against the contents being exposed. Cells or
matrix assemblies may be fitted with a device which provides a
magnetic field or other form of desirable feature. Duplex cell
pairs or matrix assemblies, which are pre-profiled may be made
available for use by organizations requiring the ability to insert
their substance, seal the matrix or duplex cell and send it to a
third party (such as a government agency for example) for
evaluation or treatment. The dielectric profiler function may be
constructed to make use of the high power array elements in an
interleaved configuration with the dielectric profiler. It can
allow for repeated profiling events to be followed by high energy
microwave irradiation events for extremely accurate control. It can
have the added benefit of avoiding the need to move the target
material (2) during the profiling event or the microwave
irradiation event, or both. The position of the matrix panels can
be adjustable and they may be configured automatically, if desired,
by computer control. As the relative position of the panel is
altered so the computer reconfigures and compensates for any change
in focal or target illumination requirements. The invention can
also be scaled to accommodate very large structures such as
shipping containers, trucks, or the like, which may be moved
automatically through the invention, as described for smaller
targets such as letters, boxes, or the like. In such cases, array
scanning techniques, doppler shift measurement and pulsed operation
would provide benefits for large scale structure analysis. By
configuring matrix panels in a cubic configuration, a 3D image of a
target(s) internal structure may be constructed from a series of
measurements using a uniform field absorption profile. For large
area targets, some form of measurement correction, such as using
doppler shift, or the like, could be included. For biological
substances or objects, pulsed operation and the ability to
accurately focus the energy ensures maximum control and minimal
damage to surrounding substances.
[0038] As can be easily understood from the foregoing, the basic
concepts of the present invention may be embodied in a variety of
ways. The invention involves numerous and varied embodiments of a
microwave sterilization system and methods of making and using such
microwave sterilization system.
[0039] As such, the particular embodiments or elements of the
invention disclosed by the description or shown in the figures
accompanying this application are not intended to be limiting, but
rather exemplary of the numerous and varied embodiments generically
encompassed by the invention or equivalents encompassed with
respect to any particular element thereof. In addition, the
specific description of a single embodiment or element of the
invention may not explicitly describe all embodiments or elements
possible; many alternatives are implicitly disclosed by the
description and figures.
[0040] It should be understood that each element of an apparatus or
each step of a method may be described by an apparatus term or
method term. Such terms can be substituted where desired to make
explicit the implicitly broad coverage to which this invention is
entitled. As but one example, it should be understood that all
steps of a method may be disclosed as an action, a means for taking
that action, or as an element which causes that action. Similarly,
each element of an apparatus may be disclosed as the physical
element or the action which that physical element facilitates. As
but one example, the disclosure of a "profiler" should be
understood to encompass disclosure of the act of
"profiling"--whether explicitly discussed or not--and, conversely,
were there effectively disclosure of the act of "profiling", such a
disclosure should be understood to encompass disclosure of a
"profiler" and even a "means for profiling." Such alternative terms
for each element or step are to be understood to be explicitly
included in the description.
[0041] In addition, as to each term used it should be understood
that unless its utilization in this application is inconsistent
with such interpretation, common dictionary definitions should be
understood to included in the description for each term as
contained in the Random House Webster's Unabridged Dictionary,
second edition, each definition hereby incorporated by
reference.
[0042] Thus, the applicant(s) should be understood to claim at
least: i) each of the microwave profiling or sterilization devices
herein disclosed and described, ii) the related methods disclosed
and described, iii) similar, equivalent, and even implicit
variations of each of these devices and methods, iv) those
alternative embodiments which accomplish each of the functions
shown, disclosed, or described, v) those alternative designs and
methods which accomplish each of the functions shown as are
implicit to accomplish that which is disclosed and described, vi)
each feature, component, and step shown as separate and independent
inventions, vii) the applications enhanced by the various systems
or components disclosed, viii) the resulting products produced by
such systems or components, ix) methods and apparatuses
substantially as described hereinbefore and with reference to any
of the accompanying examples, x) the various combinations and
permutations of each of the previous elements disclosed.
[0043] The claims set forth in this specification are hereby
incorporated by reference as part of this description of the
invention, and the applicant expressly reserves the right to use
all of or a portion of such incorporated content of such claims as
additional description to support any of or all of the claims or
any element or component thereof, and the applicant further
expressly reserves the right to move any portion of or all of the
incorporated content of such claims or any element or component
thereof from the description into the claims or vice-versa as
necessary to define the matter for which protection is sought by
this application or by any subsequent continuation, division, or
continuation-in-part application thereof, or to obtain any benefit
of, reduction in fees pursuant to, or to comply with the patent
laws, rules, or regulations of any country or treaty, and such
content incorporated by reference shall survive during the entire
pendency of this application including any subsequent continuation,
division, or continuation-in-part application thereof or any
reissue or extension thereon.
[0044] The claims set forth below are intended describe the metes
and bounds of a limited number of the preferred embodiments of the
invention and are not to be construed as the broadest embodiment of
the invention or a complete listing of embodiments of the invention
that may be claimed. The applicant does not waive any right to
develop further claims based upon the description set forth above
as a part of any continuation, division, or continuation-in-part,
or similar application.
* * * * *