text:
|Publication number
|Publication type
|Publication date
|Nov 24, 1970
|Filing date
|Apr 10, 1969
|Priority date
|Apr 10, 1969
|Publication number
|Epis James J
|Original Assignee
|Sylvania Electric Prod
|Export Citation
|BiBTeX, EndNote, RefMan
|Patent Citations (3), Referenced by (3), Classifications (17)
|External Links: USPTO, USPTO Assignment, Espacenet
Nov. 24, 1970 J. J. EPIS 3,543,276
BROADBAND CIRCULARLY POLARIZED FAN-SHAPED BEAM ANTENNA Filed April 10. 1-969 4 Sheets-Sheet 1 INVENTOR JAM ES J. EPIS B Mxm AGENT J. J. EPIS 3,543,276
4 Sheets-Sheet 2 Nov. 24, 1970 BROADBAND CIRCULARLY POLARIZED FAN-SHAPED BEAM ANTENNA Filed April 10, 1969 a W mm A N. W w NS G E M A III M NL M Y B \N \mm \\\\\\1% E: n X
Nov. 24, 1970 J. J. EPIS 3,543,276
BROADBAND CIRCULARLY POLARIZED FAN-SHAPED BEAM ANTENNA Filed April 10, 1969 4 Sheets-Sheet 3 INVENTOR.
E P 1 s I JAMES J.
AGENT Nov. 24, 1970 J. J. EPIS 3,543,276
BROADBAND CIRCULARLY POLARIZED FAN-SHAPED BEAM ANTENNA Filed April 10, 1969 4 Sheets-Sheet 4 VERTICAL POLARIZATION 6 odbs l0 s 20 HORIZONTAL POLARIZATION IE- El VERTICAL POLARIZATION AGENT United States Patent r 3,543,276 BROADBAND CIRCULARLY POLARIZED FAN- SHAPED BEAM ANTENNA James J. Epis, Sunnyvale, Calif., assignor to Sylvania Electric Products Inc., a corporation of Delaware Filed Apr. 10, 1969, Ser. No. 814,910 Int. Cl. H01q 19/00, 3/00 US. Cl. 343-756 7 Claims ABSTRACT OF THE DISCLOSURE This antenna comprises a circularly polarized conical horn that illuminates a cylindrical parabolic reflector. The horn has a relatively small aperture in one end thereof and a longitudinal axis that is tilted with respect to the reflector in the plane containing the directrix and focal line of the reflector, A quarter-wave plate and a resistanceabsorption card are oriented at 45 with respect to each other in a circular waveguide connected to the other end of the horn. The aperture of the horn is located on the focal line of the reflector.
BACKGROUND OF THE INVENTION The invention herein described was made in the course of or under a contract or subcontract thereunder, with the United States Army.
This invention relates to antennas and more particularly to a fan-shaped beam antenna that is capable of receiving electromagnetic wave signals of any linear polarization, Antenns used in azimuth direction finding (DF) applications receive signals from a number of different target antennas. Since the source of a particular received signal is often unknown, however, the following parameters defining the received signal are unknown:
(1) polarization orientation; (2) signal frequency;
(3) elevation angle; and
(4) azimuth angle.
In order to receive signals having any polarization orientation and to accurately determine the direction of the associated target antenna with a minimum number of antennas and associated receiver circuits, it is desirable that the DF antenna be circularly polarized, operate over a broad band of frequencies, and produce a beam having an azimuth boresight direction that is substantially independent of the polarization orientation of the received signal. The width of the beam in the elevation plane should be broad in order to receive a maximum number of signals. The width of the beam in the azimuth plane should be narrow, however, in order to precisely determine the azimuth direction of a target antenna.
In operation, the DF antenna is rotated in azimuth while the operating frequency of receiver equipment is swept over a band of frequencies at a rate that is much greater than the rotation rate of the DF antenna. Since the sweep rate is related to time constants of the receiver that are fixed, it is also desirable that the width of the azimuth beam be substantially independent of the frequency of a received signal.
An object of this invention is the provision of an im- Patented Nov. 24, 1970 proved directional antenna having a fan-shaped beam and satisfying the aforementioned considerations.
Another object is the provision of an antenna providing a circularly polarized fan-shaped beam.
Another object is the provision of a circularly polarized fan-shaped beam antenna having substantially constant half-power beam widths that are narrow in one plane and broad in an orthogonal plane over a frequency band greater than 1.5 :1.
A further object is the provision of a fan-shaped beam antenna wherein the angular direction of the azimuth boresight axis of the antenna beam is substantially independent of both the frequency and polarization of a received signal.
SUMMARY OF THE INVENTION In accordance with this invention, a circularly polarized fan-shaped antenna beam is provided by illuminating a cylindrical parabolic reflector with a feed having a center line that is tilted with respect to the reflector in a plane containing the directrix and focal lines of the reflector. The aperture of the antenna feed has a circular cross-section. In a preferred embodiment of the invention, the reflector is illuminated by a conical horn.
DESCRIPTION OF DRAWINGS FIG. 1 is a front view of an antenna embodying this invention;
FIG. 2 is a side view of the antenna of FIG. 1;
FIG. 3 is a section of the antenna feed assembly taken along line 3-3 in FIG. 2;
FIG. 4 is a section of the antenna feed assembly taken along lines 44 of FIG. 1;
FIG. 5 is a section of the antenna feed assembly taken along line 5-5 of FIG. 1;
FIG, 6 is a top view of the quarter-wave plate in the antenna feed assembly taken along line 66 in FIG. 5;
FIG. 7 is a side view of FIG. 6; and
FIGS. 8 and 9 are typical azimuth and elevation radiation patterns, respectively, illustrating the operation of the antenna of FIG. 1.
The scale factor of the illustrations in FIGS. 4-7 is twice the scale factor in FIG. 3, for illustrative purposes.
DESCRIPTION OF PREFERRED EMBODIMENT Referring now to FIGS. 1 and 2, this antenna comprises a reflector 1 which is illuminated by an antenna feed assembly 2. The reflector is secured to a plate 3 which is bolted to the top of an enclosure 4. The feed assembly is secured in a split bracket 5 which is also bolted to plate 3. The enclosure is mounted on a pedestal 6 which rotates the enclosure and thus the antenna and the fanv shaped beam produced thereby.
Reflector 1 is a cylindrical parabolic section that is tilted, see FIG. 2, so that the vertex line V thereof makes an acute angle a with respect to the vertical. The longitudinal axis XX of the feed assembly is located in the plane formed by a directrix D of the reflector and the vertex line V, i.e., in the plane of the paper in FIG. 2. This plane through the feed assembly and containing axis XX is normal to the plane of the paper in FIG. 1. As illustrated in FIG. 2, the feed assembly is tilted with respect to the reflector so that the axis XX forms an acute angle [3 with respect to the directrix D. This tilted orientation of the feed assembly (i.e., tilt feeding) is different from off-set feeding of a parabolic cylinder by a linear array of feeds to obtain electronic scanning of the antenna beam. In an off-set fed parabolic cylinder antenna, the longitudinal axis of each feed makes an angle with respect to its directrix D which is in a plane that is normal to the plane defined by the directrix and vertex lines of the reflector rather than in this latter plane in accordance with this invention.
The antenna feed assembly 2 is positioned so that the focal line F of the reflector passes through the aperture of the feed which is spaced the slant height it above plate 3. Thus, in azimuth DF applications in which the antenna is receiving signals, the principal ray R and reflected rays R each makes an angle 90-B with respect to the vertex line V. Electromagnetic wave signals are coupled between the antenna feed assembly and electronic receiving equipment such as a down-converter located in enclosure 4 by waveguide 7.
Referring now to FIG. 3, the antenna feed assembly comprises a rectangular to circular waveguide transition section 10, and waveguide sections 11 and 12. Waveguide section 11 is a split housing construction comprising two similar parts 14a and 14b, see FIG. 4. Each of the parts 14 has a semi-circular groove 15 therein so that a circular waveguide is formed when the parts 14a and 14b are bolted together. Recesses 16 and 17 are formed in the edges of the parts 14 and the surfaces of the grooves.
A resistance card 18 is located in the opening in section 11. Resistance card 18 may, by way of example, be a metalized sheet of mica having a constant thickness of approximately 0.005 inch for R-band. It is shown much thicker than this, however, in FIG. 4 for illustrative purposes. The resistance card is symmetrical about the center line XX of the waveguide and has tapered sides which terminate on the center line. Shoulders 19 and 20 on the center section of the card fit into the recesses 16 and 17, respectively, to locate and secure the card in the waveguide.
Waveguide section 12 comprises a length of circular waveguide 24 having one end 25 which is flared to form a conical horn that illuminates the reflector. A cover 26 that is made of Rexolite is secured over the horn aperture by a metal cap 27 to keep foreign material out of the feed assembly. The cover has a constant thickness of approximately 0.010 inch and has flat surface normal to the longitudinal axis of the feed assembly so that the cover does not function as a lens.
As illustrated in FIGS. 3 and 5, a quarter-wave plate 28 is located in circular waveguide 24. The quarter-wave plate is symmetrical about the center line XX of the feed assembly and is oriented at with respect to the resistance card and the plane defined by the lines D and V. Plate 28 is milled from a block of Rexolite and comprises a plurality of steps on opposite sides thereof (see FIGS. 6 and 7). The quarter-wave plate is press fitted into waveguide 24. Alternatively, the plate may be secured in the waveguide by dielectric screws (not shown) which extend through the waveguide wall and contact the edges of the plate. Waveguide transition 10 and section 12 are rigidly secured to opposite ends of waveguide section 11 by screws.
The operation of this antenna will now be described while considering the antenna as if it were transmitting electromagnetic wave signals. Consider that a linearly polarized wave is propagating in the dominant mode in rectangular waveguide 7 and circular waveguide section 11. This wave is not affected by resistance card 18 since the wave is polarized normal to the plane of the resistance card. Stated differently, the electric field of the dominant mode is perpendicular to the plane of the resistance card and is therefore not absorbed by the latter. Quarter-wave plate 28, however, is oriented at a 45 angle with respect to the plane of the resistance card 18 and the electric field of the linearly polarized wave. Thus, one component of the electric field is perpendicular to and another equal amplitude component is parallel to the plane of the quarter-wave plate. In propagating through circular waveguide 24, the phase of the electric field component that is parallel to the plane of the quarter-wave plate is delayed relative to the phase of the other orthogonal electric field component. Thus, an electromagnetic wave signal is radiated by conical horn 25. For the orientation of the quarter-wave plate illustrated in FIGS. 3 and 5 the ray R is right-hand circularly polarized. If the quarter-wave plate is rotated 90 in circular waveguide 24, signals radiated by horn 25 are left-hand circularly polarized. The ray R of the antenna has a polarization screw sense opposite to that of ray R in each case.
In practice, a small portion of the circularly polarized wave incident on the horn is reflected back toward the quarter-wave plate. This circularly polarized reflected wave has a sense opposite to that of the incident wave so that the former wave is converted to a linearly polarized wave. The electric field of this linearly polarized reflected wave is parallel to the plane of the resistance card and is therefor absorbed by the latter. If the resistance card were not present in waveguide section 11, the linearly polarized reflected signal would be reflected by rectangular waveguide 7 back toward plate 28. This new reflected wave would be converted by the quarter-wave plate to a third circularly polarized wave having a sense opposite to that of the original circularly polarized incident wave. Transmission of both of these circularly polarized waves would cause the polarization axial ratio of the antenna to increase. Thus, by employing resistance card 18 to absorb a small portion of the available signal energy, small values of polarization axial ratios are preserved.
The radiation pattern associated with the conical horn 25 is approximately a symmetrical surface of revolution about the horn axis XX. The horn has an aperture, however, that is located on the focal line of the cylindrical parabolic reflector and an axis XX that is tilted in the plane of the vertex and focal lines. In this configuration, radiation from the horn is diffracted by the reflector to form a fan-shaped beam having a narrow azimuth beamwidth in a plane parallel to the ground, see FIG. 8, and a broad elevation beamwidth in the vertical plane containing the focal and vertex lines, see FIG. 9.
Blockage of radiation from the reflector by the feed assembly is employed to advantage in this invention to shape the antenna radiation pattern in the vertical plane and thereby reduce the amount of radiation illuminating the earth over which the antenna is mounted. Specifically, the feed assembly is oriented at the angle )3 in front of a portion of the reflector so that the feed scatters the radiation incident on it after reflection from the parabolic cylinder 1. Thus, radiation from the antenna in the vertical plane at negative angles with respect to the horizontal, i.e., the angle 0 in FIG. 9, is reduced and the radiation pattern shape in the elevation plane is caused to be slightly asymmetrical with respect to the direction of maximum radiation, which is approximately along the line 30 that corresponds to the direction of the ray R in FIG. 2.. The reflector is tilted to make the angle a with respect to the vertical in order to make the relative signal level at zero elevation, i.e., at the earths surface, approximately 3 db below the maximum signal level of the beam in the elevation plane.
By way of example, an antenna embodying this invention that was built and tested had the following dimensions and characteristics:
Reflector 1 Vertex line length: 10.62 inches. Width: 6.825 inches. Focal length: 1.751 inches. Vertex angle a: 13 degrees.
Horn 25 Aperture diameter: 0.610 inch.
Taper angle 1: degrees.
Slant height h: 4.944 inches.
Tilt angle ,9: 32 degrees.
Aperture-to-reflector spacing: 1.751 inches.
Waveguide Sections 11 and 12 Inner diameter: 0.457 inches.
Quarter-wave plate 28 Width: 0.457 inch.
Total length: 1.111 inch.
Number of steps: 6.
Length: s =0.139 s =0.144 s =0.159 s =0.l84 inch.
Thickness: t =0.072 t =0.055 t =0.035 1 0.010
Resistance card 18 Center length 1 0.78 inch.
Taper length 1,: 1.22 inches.
Taper angle 7: 10.6 degrees.
Thickness: 0.005 inch.
Resistivity: 200 ohms/ square.
Frequency band: 16 to 26 gHz.
VSWR (max.): 1.24: 1.
Polarization axial ratio Maximum: 2.4 db.
Nominal: 1.2 db.
Azimuth half-power beamwidth Nominal: 6.65 degrees. Variation: :08 degrees.
Elevation half-power beamwidth Nominal: 50 degrees. Variation: :3 degrees.
This antenna operated over a frequency bandwidth of greater than 1.6:1 in K -band. The aperture diameter was approximately 1% times the diameter of the air-filled circular waveguide 24, i.e., 1.03 Wavelengths, at the center frequency (21 gHz). This relatively small conical horn was located on the focal line of the reflector. The azimuth half-power beamwidth varied less than 112% as compared to :24% variation for a typical antenna (assuming that the beamwidth of the latter varies linearly with wavelength) operating over the same frequency bandwidth. Similarly, the elevation half-power beamwidth varied less than 16% as compared to 124% for a typical antenna. The maximum side lobe levels on the azimuth and elevation patterns weer at least -19 db and db, respectively, relative to the maximum of the beam. The maximum side lobe level of the more important and relatively narrow azimuth radiation pattern, however, was at most frequencies more than 30 db below the beam maximum. The direction of the boresight axis of the azimuth radiation pattern was substantially constant as the polarization of an incident signal was varied through all possible values over the frequency band of 16 to 24.5 gHz. The maximum variation of the direction of the boresight axis over the frequency band of 24.5 to 26 gHz was :055 degree from the nominal direction as a function of incident polarization orientation. The maximum axial ratio of this antenna was less than 2.4 db, with values of 1.2 db being more common. The polarization axial ratio was measured over a 60 section on the elevation pattern.
Although it is not known exactly why the azimuth and elevation beamwidth patterns (e.g., see FIGS. 8 and 9, respectively) are so nearly constant when the antenna is operated over a broad band of frequencies greater than 1.5 1, several design considerations related to this feature were determined empirically. As stated previously, it is desirable that a DP antenna receive signals having any linear polarization. Although a horn with an aperture having either a square or circular cross section will propagate a circularly polarized wave, and thus any linear polarization, it was discovered that in order to accomplish the objects of this invention the aperture of the antenna feed must have a circular cross section. In the preferred embodiment of this invention the antenna feed is a conical horn. It was determined that the diameter of the feed aperture must also be small, preferably between 0.95 and 1.25 wavelengths at the center operating frequency of the antenna, for the orientation of the boresight axis of the antenna to be independent of frequency and polarization orientation of received signals over a broad band of frequencies. It is also desirable that the slant height h spacing of the aperture be approximately 46% of the vertex length of the reflector, that the focal length of the parabolic reflector be between 2.8 and 3.2 wavelengths, and that the tilt angle B of the feed born be between 29 and 35.
When the reflector was illuminated by a feed horn with an aperture having a square cross section the azimuth boresight direction of the DF antenna varied appreciably (i.e., scanned as a function of the polarization of received signals) and the azimuth pattern beam shape was asymmetrical with respect to the scanned boresight direction. Also, the magnitudes of the side lobes and the polarization axial ratios were substantially greater than those obtained when the reflector was illuminated by a conical horn having an aperture of the correct size.
The superior performance of this antenna with a conical horn feed is believed to be achieved because cross polarized currents are induced on the reflector surface by two different phenomena and the resulting pair of cross polarized currents substantially cancel each other; whereas only one of these cross polarized currents is induced on the reflector when a square horn is used so that a net cancellation of highly undesirable effects due to cross polarized currents cannot be obtained. The second set of cross polarization currents produced on the reflector by a conical horn is obtained because the electric field lines therein curve so that they are normal to the periphery of the horn. In the square horn the corresponding field lines are straight.
What is claimed is:
1. A broadband circularly polarized fan-shaped beam antenna comprising a cylindrical parabolic reflector having vertex and focal lines that are parallel to each other and define a plane, said reflector having a directrix that is orthoginal to said lines in said plane,
a feed assembly having a longitudinal axis and oriented to illuminate said reflector, said feed assembly comprising a waveguide symmetrical with respect to said axis and capable of supporting a circularly polarized wave,
a resistance card in said waveguide, said card being symmetrical with respect to said axis,
a quarter-wave plate in said waveguide between said card and one end of said waveguide and oriented at a 45 angle with respect to said card,
first means having an aperture in one end thereof, said aperture having a circular cross section, the other end of said first means being connected to said one end of said waveguide,
second means supporting said feed assembly and said reflector in a fixed relationship,
said axis being in said plane and tilted with respect to said reflector to form an acute angle with respect to said directrix,
said one end of said first means being located proximate said reflector, and
third means for moving said reflector and feed assembly for moving the fan-shaped antenna beam produced thereby.
2. The antenna according to claim 1 wherein the diameter of the aperture in the one end of said first means is in the order of one wavelength at the center operating frequency of the antenna.
3. The antenna according to claim 1 wherein said first meansv is a conical horn.
4. The antenna according to claim 3 wherein the tilt angle between said axis and the directrix is between 2 9 and 35.
5. The antenna according to claim 4 wherein the focal line of said reflector passes through the aperture of said horn, the slant height of said aperture being approximately forty-six percent of the vertex length of said reflector as measured from one end thereof, said axis being tilted toward said one end of said reflector.
"6. The antenna according to claim 3 wherein said waveguide has a circular cross section.
7. The antenna according to claim 1 wherein the focal length of said reflector is between 2.8 and 3.2 wavelengths and the aperture diameter of said horn is between 0.95
8 of the operating frequency bandwidth of said broadband circularly polarized fan-shaped beam antenna.
References Cited UNITED STATES PATENTS 2,786,198 3/1957 Weil et al. 343756 X 3,233,241 2/1966 Alford 343-756 3,495,261 2/1970 Lastinger et al. 343766 X 10 HERMAN K. SAALBACH, Primary Examiner T. VEZJEAU, Assistant Examiner US. Cl. X.R.
Wavelength and 1.25 wavelengths at the center frequency 15 33321; 343-766, 7 83 786 840
|Cited Patent
|Filing date
|Publication date
|Sep 20, 1954
|Mar 19, 1957
|Gilfillan Bros Inc
|Radar reflector for circularly polarized radiation
|May 25, 1955
|Feb 1, 1966
|Andrew Alford
|Horn for radiating circularly polarized waves
|May 8, 1968
|Feb 10, 1970
|Gardner Newell J
|Telescopic radar antenna
|Citing Patent
|Filing date
|Publication date
|Mar 16, 1982
|May 7, 1985
|U.S. Philips Corporation
|System for receiving microwave signals having orthogonal polarizations
|Oct 24, 1973
|May 2, 1974
|Thomson Csf
|Antenne mit einem parabolreflektor und einem primaerstrahler mit doppelpolarisation
|Mar 5, 1982
|Sep 22, 1982
|Receiving system for orthogonally polarized HF signals
|U.S. Classification
|343/756, 343/786, 343/783, 343/766, 343/840
|International Classification
|Cooperative Classification
|European Classification


text:
Our 2006 Awards
We laughed, we cried. Now that the campaign is over, we recognize some notable ads we didn't examine before.
November 7, 2006
Modified: November 7, 2006
eMail to a friend Printer Friendly Version
All year we've focused on what was true or false in the flood of 2006 campaign advertising, and we wrote about those that we found twisted, distorted, misleading or fabricated. Now, as we wait for the ballots to be counted, we look back on some of that ads that caught our attention for other reasons.
We offer these FactCheck.org awards just for fun.
Here they are, the FactCheck.org Awards for 2006. We present them in no particular order, and with no claim of scientific accuracy. These are just our opinions. Feel free to agree or not, as you please.
Charlton Heston Award for Worst Impersonation of Moses
This ad, set "somewhere in the mountains of Colorado," features a Moses-like figure speaking hyperbolically to God about the supposed evils of ballot initiative 42, which would amend the state Constitution to provide for an annual increase in the minimum wage that's pegged to inflation. "An annual minimum wage increase in stone for eternity," moans the faux Moses.
Busiest Supporting Actor
President Bush was far and away the most frequent supporting actor – in Democratic ads. His name or image have appeared in at least 186 Democratic ads since Oct. 1, by our count, and we probably missed some that appeared in smaller TV markets not covered by the Campaign Media Analysis Group. The strategy is clear: whether they're referring to a Republican candidate as a "supporter" of the "Bush agenda" or as a "rubberstamp," Democrats believe the President's low approval ratings are a stone they can use to sink their opponents. The Democratic Senatorial Campaign Committee's ad, "Together," which began running on Sept 19, is a classic of the genre.
Busiest Supporting Actress
Democratic Sen. Hillary Clinton of New York got the most mentions in Republican ads holding forth the supposed horrors of a Democratic-controlled Senate. We counted 11 since Oct. 1. This one from GOP Senate Candidate Pete Ricketts in Nebraska is typical, saying Democrat Ben Nelson will "vote to put Democrats in charge," including Sen. Clinton who "wants higher taxes."
The runner-up for this award is "San Francisco Liberal Nancy Pelosi," who is mentioned in at least 6 GOP ads as a reason not to vote for a Democrat who would in turn vote to make her Speaker of the House.
Kinkiest Action Figure
Independent Jewish Cowboy Kinky Friedman, who's running for governor of Texas, used the "Kinky Friedman Action Figure" as a major element of his campaign strategy. The plastic Kinky had the following responses to tough questions from reporters in this ad:
On border issues:
On getting the Democrats and Republicans to work together:
It is unclear whether the doll comes with karate chop action or hair you can style yourself.
The "Who Needs Enemies?" Award
State Rep. Bill Sali, a Republican running in
Cult Classic Award
Taken together, Robinson's ads make up an anthology he could title, "The Attack of the 40-Foot Liberal." In one that has received wide (and free!) exposure on cable news programs, Robinson compares modern day America to the Twilight Zone, illegal immigrants to intergalactic alien invaders, and equates the 1950's show Leave It to Beaver with "traditional American values." An announcer says, "You can burn the American flag and kill a million babies a year, but you can't post the Ten Commandments or say God in public." (Note to Vern: Actually, you can say God in public. The Supreme Court unanimously overturned that ruling against reciting "under God" in public schools.)
Best Send-up of an Ineffective Federal Mandate
Libertarian House candidate Phil Maymin, running in Connecticut's 4th district, ran a cable-only spot spoofing the "stand by your ad" provision of the McCain-Feingold campaign law. That's the federal requirement that candidates appear in their own ads and say "I approve this message," or words to that effect. The idea was to reduce the volume of distasteful attacks and false accusations by forcing candidates to take personal responsibility for them.
Best Musical Score
This ad's shrieking strings, reminiscent of the score in the Alfred Hitchcock classic "Psycho," seemed to us a perfect parody of much of this year's crop of attack ads, with their over-the-top appeals to fear. Imagine this score behind, for example, the RNC's ad suggesting that voting Democratic might lead to a terrorist attack with a nuclear weapon, which we critiqued here , and you get the idea.
The "Empty Calories" Award
This 15-second ad from a liberal group funded by labor unions takes the cake (so to speak) for lack of substance. It shows an elderly couple cutting a single hot dog in half to share for their meal, while the announcer asks "If George Bush and his backers in Congress privatize Social Security and cut benefits in half, what will you have to cut in half?" That wildly misrepresents Bush's proposal, which would not have touched benefits for anybody currently receiving them or about to receive them, and would have allowed benefits for future recipients to grow, though more slowly than under current law. The plan died last year for lack of Republican support in any case.
-Awards Committee: Brooks Jackson, Viveca Novak, Justin Bank, James Ficaro and Emi Kolawole
Footnotes? We don't need them here. These are just our opinions.

subset: commoncrawl


text:
We stayed here inbetween driving from death valley and Yosemite. As a cheap stopover it's fine. The room was a decent size, restaurants close by, free wifi and generally quite comfortable. We weren't expecting luxury so it suited us fine. Our room and bedding was clean. My only issues were - the breakfast is not great & the pool looked a bit dirty.
- Official Description (provided by the hotel):
- Located in beautiful downtown Bishop, California. Bishop is known as the "Mule Capital of the World" and hosts a week-long festival called "Mule Days" that has been held annually since 1969 during the week of Memorial Day, celebrating the contributions of pack mules in the area. ... more less
- Reservation Options:
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text:
|Publication number
|Publication type
|Application number
|Publication date
|Oct 30, 1979
|Filing date
|Jun 15, 1978
|Priority date
|Jun 15, 1978
|Publication number
|Richard A. Morrison
|Original Assignee
|Morrison Richard A
|Export Citation
|BiBTeX, EndNote, RefMan
|Non-Patent Citations (1), Referenced by (33), Classifications (5)
|External Links: USPTO, USPTO Assignment, Espacenet
This invention generally deals with the treatment of living tissue using radiation, and relates more particularly to a device implemented method for providing radiotherapy treatment conforming to a desired volume of tissue in a patient.
The therapeutic technique of applying dosages of radiation to tumors within the human body has been practiced for some time. Usually, only a slight difference will exist in the radio sensitivities of a tumor and the surrounding healthy tissue, with the former being somewhat more sensitive than the latter. Consequently, it is an important object in conducting radiation therapy to avoid as much injury as possible to the healthy surrounding tissue while delivering a homogeneous and adequate dose to the tumor. This presents an extremely difficult problem since the tumor comprises an irregularly configured, three-dimensional shape which is often situated well into the body and thus completely surrounded by healthy tissue.
Early attempts to minimize lethal damage to the healty tissue surrounding the treated tumor involved simply directing a rectangularly-shaped beam of radiation onto the tumor and rotating the beam around the patient (and thus, around the tumor) so that the resulting volume of tissue subjected to radiation was cylindrical in shape and included the irregularly configured tumor portion therewithin. Of course, this early technique resulted in destruction of a considerable amount of normal healthy tissue surrounding and sometimes enveloped by the tumor.
A more recent approach to the problem has succeeded in confining the treated area to the volume of the tumor and is commonly known in the art as "comformation" radiotherapy. Heretofore, conformation radiotherapy has involved the use of apparatus which conforms the beam of radiation to the shape of the tumor as the latter is rotated relative to the radiation beam. One method of practicing conformation radiotherapy involves interposing a beam shaping radiation shield between the source of radiation and the tumor, and then shifting the shield in synchronization with the rotation of either the patient or the radiation beam in a manner to continuously alter the cross-sectional shape of the beam as different sides of the tumor are exposed to such beam. Various types of apparatus for producing the needed synchronized shielding which continuously alters the cross-sectional shape of the beam have been employed in the past as discussed by Shinji Takahashi in: Conformation Radiotherapy, Department of Radiology, Nagoya University School of Medicine, Japan, ACTA Radiologica Supplementum 242, 1965 (see Chapter III, Pages 49-66). Prior art synchronized shielding apparatus typically have employed a multiplicity of differently configured, gear-driven cam elements, often operating on corresponding, shiftable, radiation shielding segments forming a diaphragm surrounding the radiation beam source. Each of the cam elements correspond to a geometrical section of a particular tumor volume of a individual patient and must therefore be tailor made for treating a particular tumor. As the radiation beam rotates around the patient, the cam elements are sychronously driven to continuously change the diaphram in a manner to alter the cross-sectional shape of the radiation beam to conform to the profile of the tumor, as the various sides or "profiles" of such tumor are presented to the beam while the latter rotates. From the foregoing, it is clearly apparent that the prior art apparatus for practicing conformation radiotherapy was particularly complex with respect to the mechanisms that were employed, moreover, the radiotherapy method of treatment using the mentioned prior art apparatus was particularly time-consuming, and therefore inefficient, since numerous mechanisms were required to be assembled and disassembled in the course of treating different patients.
To further complicate the problems associated with conformation radiotherapy, it is necessary to devise a means of protecting radiosensitive normal tissues and organs such as the spinal cord, kidneys, ocular lens, and small intestine, which organs lie in the path of the radiation beam, between the tumor to be treated and the radiation source. The prior art method of protecting healthy organs lying in the radiation beam path involved the placement of radiation absorbing structures between the source of radiation and the patient which function to reduce or "hollow out" the dosage of radiation applied to the healthy organs. These radiation absorbing structures possessed geometrical dimensions corresponding in direct proportion to the healthy organ to be protected, and in some cases were rotated in synchronization with the rotation of the radiation source where the healthy organ was of irregular shape. These radiation absorbing protective structures, commonly known in the art as "central absorbers" due to the fact that they absorb a portion of the radiation lying within central areas of the radiation beam, were less than completely effective in protecting the healthy organ because the thickness of the prior art absorber was dictated by the cross-sectional thickness of the organ being protected. This thickness limitation is due to the fact that the prior art method of protecting healthy organs requires that the central absorber be rotated relative to the radiation beam in a manner to cause various sides of the central absorber to be presented to the radiation beam as the latter rotates around the patient. Because the thickness of the central absorber is dictated by the cross-sectional area of the organ to be protected and must be directly proportional to the latter, the thickness of the central absorber is insufficient to completely absorb the radiation impinging thereon, and consequently allows a portion of such radiation to pass therethrough and onto the organ which is intended to be protected. Since it is optimally desired to prevent any radiation whatsoever from being applied to the healty organ, the prior art method of using rotating central absorbers having cross section geometries corresponding to the organ to be protected, are less than completely effective in shielding such organ from undesired radiation treatment. Moreover, it is quite clear that the complexity of the apparatus required to practice the previous method is considerably increased by the need for mechanism to rotate one or more central absorbers in synchronization with the shiftable shielding segments which continually change the cross section configuration of the radiation beam to correspond to different profiles of the tumor, while the radiation source is rotated around the patient. In fact, due to the excessive complexity, and therefore cost, of prior art radiotherapy apparatus of the type described above, conformation type radiotherapy using the "hollowed-out" technique has thus far enjoyed only limited use.
From the foregoing, it is readily apparent that there is a clear need in the art for a novel method of conformation radiotherapy which is considerably more efficient than prior art techniques, and which employs apparatus which reduces equipment cost and operating expenses to a level which will permit wide scale use of the conformation radiotherapy treatment method.
The present invention provides a device implemented method for practicing conformation cineradiotherapy which is highly efficient in terms of the number of patients which may be successively treated and which employs cineradiotherapy apparatus that is economical from a manufacturing standpoint while also yielding increased protection of healthy organs when using the "hollowed-out" technique of protecting healthy tissues. Conventional, radiotherapy apparatus having a radiation beam source mounted for rotation around a stationarily held patient, is adapted to have removably mounted for rotation thereon a circular treatment reel dedicated to the treatment of a particular tumor of an individual patient. The treatment reel is provided with a plurality of field shaping, radiation shields releasably held on the periphery thereof, which shields including cut-out portions corresponding to various cross-sectional profiles of the tumor to be treated and further may include a central radiation absorber disposed within the cut-out portions and corresponding in shape to the profile of a healthy organ to be protected. Each of the radiation shields, including the central absorber portions thereof, are of a thickness sufficient to almost completely preclude the passage of radiation therethrough. Gantry structure for positioning a radiation source in spaced relationship to the patient provides motorized, gear-driven, roller mounting of the treatment reel around the radiation source whereby to allow rotation of the reel around the radiation source in a manner to successively shift each of the radiation shields into a shielding position between the radiation source and the patient. With a treatment reel mounted in its operative position on the rotating gantry, the latter is rotated thereby likewise rotating the radiation source along with the reel between a plurality of discrete, treatment positions around the patient, corresponding in number to the number of radiation shields carried by the treatment reel. As the radiation source is moved to each new treatment position, thereby exposing a different profile of the tumor to such source, a different radiation shield having cut-out portions therein corresponding to the profile of the tumor then presented to the source, is shifted into shielding relationship between the source and the tumor, whereupon a predetermined dosage of radiation is delivered from the source thereof to the corresponding profile of the tumor as the gantry is rotated over a known arc, e.g. 30 degrees, to the next treatment starting position. After delivering such predetermined dosage to one profile of the tumor, the treatment reel is rotated to bring a subsequent radiation shield into the shielding position, which corresponds to the profile of the tumor next to be treated. The steps of rotating the radiation source between successive treatment positions around the patient and selectively rotating the treatment reel to interpose the various radiation shields into shielding relationship between corresponding profiles of the tumor and the radiation source, continues until the prescribed number of profiles of the tumor have all received the predetermined dosage of radiation. Inasmuch as the full thickness, central absorber needed for protecting healthy organs is provided integral with each of the plurality of radiation shields, it can be appreciated that mechanism is not required for rotating a central absorber in synchronization with the rotation of the radiation source about the patient. Upon completion of the treatment of one tumor in a patient, the associated treatment reel may be simply removed from the gantry and replaced with a second treatment reel having a plurality of radiation shields similarly mounted thereon which correspond to the various profiles of a second tumor in another patient, whereupon treatment of the second tumor may then be commenced in a manner identical to that described above.
In the drawings:
FIG. 1 is a side elevational view of the cineradiotherapy device which is used in practicing the method in the present invention, and which forms the preferred embodiment of the apparatus of the present invention, shown in operative relationship to a patient supporting treatment table;
FIG. 2 is a front elevational view of the treatment head having a treatment reel mounted in operative relationship thereon, parts being broken away in section to more clearly reveal means for releasably holding the reel on the treatment head;
FIG. 3 is a fragmentary front elevational view of the cineradiotherapy device showing a treatment reel mounted in operative relationship thereon with the radiation shield assemblies having been removed from the reel, and depicted in the reel exchanging position thereof;
FIG. 4 is a fragmentary, rear view of the treatment head, parts being broken away to more clearly show the gear-driven relationship between the treatment head and a treatment reel;
FIG. 5 is a fragmentary, rear view of a portion of the treatment head depicting motorized means for rotating the treatment reel relative to the treatment head and for locking the former into a treatment position with respect to the latter;
FIG. 6 is a fragmentary, sectional view taken along the line 6--6 in FIG. 2;
FIG. 7 is a fragmentary, sectional view taken along the line 7--7 in FIG. 2;
FIG. 8 is a fragmentary, sectional view taken along the line 8--8 in FIG. 2;
FIG. 9 is a fragmentary, sectional view taken along the line 9--9 in FIG. 7;
FIG. 10 is a fragmentary, top view of a portion of the treatment head depicting a reel positioning switch and trip dog for controlling the rotational position of the treatment reel; and,
FIG. 11 is a plan view of one of the radiation shield assemblies shown removed from a treatment reel, and including a central radiation absorber.
For sake of convenience, a description of the construction of the apparatus will first be provided, followed by a discussion of the operation of the apparatus in connection with the use thereof in practicing a novel method of radiotherapy.
Referring first to FIG. 1, a cineradiotherapy system generally indicated by the numeral 20 includes a pivotal treatment table 22 of the conventional type having a horizontally extending platform 24 for supporting a patient thereupon a spaced distance above the floor 27, and further includes a cineradiotherapy treatment device generally indicated by the numeral 26. The device 26 includes a movable portion 28 which is mounted on a stationary portion 30 for rotation about a horizontally extending axis 32. The movable portion 28 includes a horizontally extending supporting structure in the nature of a gantry 34 terminating in a treatment head 36 spaced from the horizontal axis 32 and in overlapping relationship to the platform 24, while a horizontally extending radiation safety shield 38 is mounted on the opposite extremity of the movable portion 28, in spaced, opposed relationship to the treatment head 36, and aligned in a vertical plane extending through the latter. Shield 38 is made of a suitable radiation absorbing material to prevent escape of stray radiation passing from the treatment head 36 past platform 24. The stationary portion 30 of the device 26 includes conventional motorized means for producing rotational movement of the movable portion 28 about the axis 32 and may also include a suitable power supply for energizing a later discussed, suitable source of radiation mounted in the treatment head 36. A cut-out portion 40 in the floor 27 beneath the platform 24 is provided to allow clearance of the treatment head 36 upon rotation of the latter about the horizontal axis 32.
Referring now also to the remaining figures, the treatment head 36 is adapted to have removably mounted for rotation thereon a treatment reel 42. Treatment reel 42 comprises a drum-like cylindrical structure having the opposite ends thereof open and includes a front and rear flange 44 and 46 respectively having secured therebetween, by any suitable means, at equally spaced radial locations around the periphery thereof the longitudinally extending support members 48 which are formed from any suitable rigid material such as steel or the like. Each of the support members 48 include oppositely beveled, adjacent upper surface areas 50 and are further provided with longitudinally extending slots 53 on opposite sides thereof. Certain selected ones of the support members 48, such as members 48a, 48b, and 48c, include a longitudinally extending, V-shaped groove 52 in the inner surface thereof adjacent the treatment head 36 while portions of the rear flange 46 in registration with the V-shaped grooves 52 in the support members 48 are provided with V-shaped openings 54 therein for purposes which will become later apparent. Each of the members 48 also includes an arcuately shaped V-shaped groove 57 in the inner surface thereof adjacent the front flange 44 which extends in a circumferential direction around the treatment reel 42.
A plurality of radiation shield assemblies each generally indicated by the numeral 56 includes a rectangularly shaped support plate 58 comprising material which is transparent to radiation having mounted on the upper, outer surface thereof, by any suitable means such as screws or the like, an outer, radiation shield 60 having cut-out portions 62 therethrough within which there is disposed a central radiation absorber 64, likewise secured by any suitable means to the upper surface of support plate 58. Radiation shield 60 and central absorber 64 may be manufactured from any suitable material adapted to absorb and prevent the transmission therethrough of radiation. The cut-out portions 62 in the radiation shield 60 will conform in geometrical shape to a particular profile of the volume of tissue in the patient to be treated, while the central absorber 64 will likewise conform in cross-sectional shape to a healthy organ to be protected which lies between a later discussed source of radiation and the volume of tissue within the patient to be treated. The sidewalls of both the radiation shield 60 and central absorber 64 adjacent the cut-out portions 62 are slightly inclined with respect to the support plate 58 in order to prevent an undesired radiation shadowing effect on the volume of tissue to be treated, and it is important that both the radiation shield 60 and central absorber 64 be sufficiently thick to almost completely prevent the passage of radiations through the solid portions thereof. Both the radiation shields 60 and central absorber 64 may be manufactured in accordance with a method for making a focused shield disclosed in U.S. Pat. No. 3,937,971.
The front flange 44 includes a cut-out portion 66 in the periphery thereof of sufficient width to allow the passage of the radiation shields 60 therethrough, and further includes a pair of slots 68 on opposite sides of the cut-out portion 66 to complementally receive the plate 58 therethrough. Thus, slots 53 and 68 slidably receive the plate 58 therewithin and function to position and partially hold the radiation shield assembly 56 in proper alignment between the front and rear flanges 44 and 46, while a shoulder bolt 70 held within threaded apertures passing through the bevel surface areas 50 of the support members 48 and through corresponding perforations in the margins of plate 58 releasably secure the radiation shield assembly 56 in place.
The treatment reel 42 further includes an annular, toothed reel gear 72 suitably mounted on the back of the rear flange 46 which has a plurality of gear teeth 74 on the inner periphery thereof that are adapted to meshingly engage a later discussed drive gear 76. Reel gear 72 further includes a plurality of circumferentially spaced, longitudinally extending apertures 78 therethrough radially aligned with the radiation shield assemblies 56 and adapted to receive therewithin a plunger 80 associated with a later discussed solenoid operated locking device 82. The reel gear 72 is provided with a plurality of longitudinally and outwardly extending actuating nodes 84 circumferentially spaced at regular intervals with respect to the radiation shield assemblies 56.
The treatment head 36 has a suitable source of radiation 86 mounted centrally therewithin, around which source a keyhole shaped layer of radiation shielding material 88 may be provided to avoid undesirable escape of radiation therefrom. The shielding material 88 includes a conically shaped cavity 90 therewithin placing an area in the periphery of the cylindrically shaped treatment head 36 in communication with the radiation source 86. As best seen in FIGS. 1 and 2, the cavity 90 permits radiation from the radiation source 86 to be directed through the radiation beam opening 92 in the head 36, thence through one of the reel openings 59 and corresponding radiation shield assembly 56 in registration with the beam opening 92 to a patient disposed on the platform 24, in alignment with the radially extending axis 94. Suitable means may be provided including beam collimating means (not shown) for limiting the cross-sectional area of the radiation beam passing through the opening 92 to the cross-sectional area of the radiation shield 60 in order to prevent undesired escape of radiation around the outer perimeter of the radiation shield 60.
The treatment head 36 includes a stairstep, annular, cut-out area in the periphery thereof which forms a first reel-receiving notch 96 therein for receiving the support members 48, rear flange 46, and reel gear 72, and further forms a second reel-receiving notch 98 for receiving the inner periphery of the front flange 44. A plurality of reel loading ball elements 100 suitably secured to the treatment head 36 at circumferentially spaced locations around the periphery of the latter and aligned with the V-shaped grooves 52, extend into the first reel-receiving notch 96 and are in communication with the V-shaped grooves 52 and 57. As will become apparent later, ball elements 100 in combination with the V-shaped grooves 52 provide a means for guiding the reel 42 onto the head 36. Treatment head 36 has three, recessed areas 102 in the outer periphery thereof, circumferentially spaced approximately 120� apart from each other. Means for releasably holding and supporting the reel 42 on the head 36 in the nature of a reel-supporting, roller assembly mounted within each of the recessed areas 102 includes a pair of longitudinally spaced roller members 104 and 106 respectively received within corresponding, annular channels provided in the associated flanges 44 and 46, and rotatably mounted on opposite extremities of an inclined axle element 108. Axle element 108 includes an enlarged central portion having a threaded aperture therethrough for threadably receiving an outwardly extending, threaded output shaft 110 of a selectively energizable motor means 112 adapted, when energized, to selectively rotate the output shaft 110 in either rotational direction. A stabilizing link 114 has the opposite extremities respectively pivotally coupled to the treatment head 36 and central portions of the axle element 108 in order to prevent rotation of the latter with respect to output shaft 110 upon rotation of the latter, it being understood that the pivotal mounting of the stabilizing link 114 include provision for lost motion to allow free reciprocal movement of the axle element 108. Means for rotating the treatment reel 42 relative to the treatment head 36 are provided which include a drive gear 76 meshingly engaging the gear teeth 74 associated with the reel gear 72, drive gear 76 being secured on the rotatable output shaft 116 of a motor means 118, such as an ordinary electric motor, which is mounted within a recessed portion 120 of the treatment head 36. Means for preventing the rotation of the treatment reel 42 relative to the treatment head 36, and for locking one of the radiation shield assemblies 56 in registration with the opening 92, are provided in the nature of a motor device 82, such as a solenoid, mounted within the recessed portion 120 and having a reciprocating output shaft 80 which is selectively insertable into the aperture 78 of the reel gear 72.
Means for sensing the position of the reel 42 relative to the head 36 and for controlling the operation of the motor means 118 to produce rotation of the reel 42 relative to the head 36 includes an electrical switch 122 secured to the treatment head 36 and having a switching element thereof connected to one extremity of a link element 124, the opposite extremity of the latter having rotatably mounted thereon an engagement wheel 126. Link element 124 is normally biased to shift the engagement wheel 126 into the space 128 between the treatment head 36 and reel gear 72 a sufficient distance to allow engagement therewith by the actuating nodes 84 upon rotation of the treatment reel 42.
Prior to discussing the method of treatment using the cineradiotherapy system 20, a description of the procedure in which treatment reels 42 are installed and removed from the treatment head 36 will first be provided. Let it first be assumed that the treatment head 36 does not have a treatment reel 42 mounted thereon and that it is desired to install such reel 42 in preparation for the treatment of a patient. The reel 42 is first positioned adjacent the cineradiotherapy device 26 in a standby position adjacent the latter while the device 26 is actuated to rotate the gantry 34, and thus the treatment head 36, until the latter is disposed at approximately a four-O'clock position with respect to the horizontal axis 32, as shown in FIG. 3. For convenience, a wheeled transportation cart (not shown) adapted for supporting one of the reels 42 at a suitable height for loading onto the treatment head 36 may be employed, and assuming such a cart or the like is being used, the V-shaped openings 54 in the rear flange 46 are aligned with, and positioned immediately adjacent to the corresponding ball elements 100, whereupon the cart (not shown) may be shifted in a manner to slide the open, rear end of the treatment reel 42 onto the treatment head 36. As the reel 42 is shifted onto the treatment head 36, the ball elements 100 are received within and engageably support the V-shaped grooves 52 in the support members 48, at the nine-O'clock, twelve-O'clock, and three-O'clock positions on the treatment reel 42 thereby reliably guiding and supporting the latter on the treatment head 36. The treatment reel 42 is shifted rearwardly onto the treatment head 36 until the annular channels in the front and rear flanges 44 and 46 are in radial alignment with the corresponding roller members 104 and 106; at this point the ball elements 100 are placed in communication with the annularly extending, V-shaped grooves 57 in each of the support members 48. Motor means 112 may then be energized to produce rotation of the output shaft 110 in a manner to shift the axle element 108 radially outward thereby shifting the roller members 104 and 106 into the channels respectively associated with the front and rear flanges 44 and 46. With the treatment reel 42 thus installed, the latter is supported for rotation about the treatment head 36 by means of the front and rear flanges 44 and 46 which are carried upon the roller members 104 and 106. The motor means 118 may then be energized to rotate the drive gear 76 which in turn drives the reel gear 72 to produce rotation of the treatment reel 42 relative to the treatment head 36. Normally, once activated, motor means 18 will produce rotation of the treatment reel 42 until one of the actuating nodes 84 engages the wheel 126 to actuate the switch 122 whereupon motor means 118 will be energized and the motor device 82 will be actuated to extend the plunger 80 into one of the apertures 78 aligned therewith. With the plunger 80 inserted into the aperture 72 it can be appreciated that the treatment reel 42 is securely locked in place and is substantially prevented from any rotational movement whatsoever. The number of apertures 78 and actuating nodes 84 correspond to the number of radiation assemblies 56 employed and are circumferentially spaced relative to each other in a manner to position one of the radiation shield assemblies 56 in alignment with the opening 92 upon successive actuations of the motor means 118. With the plunger 80 disposed within one of the apertures 78, successive energization of the motor means 118 results in deactuation of the motor device 82 and retraction of the plunger 80 to allow rotation of the treatment reel 42 until the next in the series of actuating nodes 84 produces operation of the switch 122 to deenergize the motor means 118 and actuate the motor device 82.
Although not specifically disclosed herein, the cineradiotherapy device 26 will include control means for successively rotating the treatment head 36 between a number of discrete, radial treatment positions about the horizontal axis 32, the number of such treatment positions corresponding to the number of radiation shield assemblies 56 carried by the treatment reel 42, and it may be appreciated that twelve radial treatment positions, spaced 30� apart, will be employed in connection with the preferred form of the invention disclosed herein, inasmuch as twelve radiation shield assemblies 56 are carried by the reel 42. Clearly, however, the number of radiation shield assemblies 56 employed in connection with the present invention will be dictated by the circumference of the treatment reel 42 and may vary in accordance with particular applications. In fact, obviously a fewer number of radiation shield assemblies 56 may be employed in connection with the treatment reel 42 disclosed herein, although as will become later apparent, it will generally be desirable to employ a maximum number of such radiation shield assemblies 56.
Assuming now that treatment has been completed of a particular volume of tissue in an individual patient, and that it is desired to treat a differently configured volume of tissue in the same patient, or in a different patient, the treatment reel 42 must be removed from the treatment head 36 and replaced with another treatment reel having radiation shield assemblies 56 particularly adapted for treatment of such other volume of tissue. In order to remove the treatment reel 42, the gantry 34 and treatment head 36 are rotated about the horizontal axis 32 until the treatment head 36 assumes the four-O'clock loading position depicted in FIG. 3. If desired, the previously mentioned transportation cart may be disposed beneath the treatment reel 42 and in supporting relationship to the latter when the reel 42 is delivered to the loading position shown in FIG. 3. The treatment reel 42 is then rotated until the V-shaped grooves 52 are in aligned, longitudinal registration with the corresponding ball elements 100 when the treatment head 36 is disposed in the loading position shown in FIG. 3. The motor means 112 may then be actuated to shift the axle element 108 radially inward, thereby likewise shifting the roller members 104 and 106 inwardly away from the corresponding front and rear flanges 44 and 46 and in clearing relationship to each of the latter. With the weight of the treatment reel 42 being supported by a transportation cart or the like, the reel 42 may be shifted outwardly away from the treatment head 36, over the ball elements 100, and the reel 42 may be moved away from the treatment area while a second treatment reel 42 associated with the treatment of a different volume of tissue in a patient may then be installed on the treatment head 36 in a manner similar to that described previously.
Having thus described the general operational characteristics of the cineradiotherapy device 26, attention is now turned to a discussion of a novel method of radiotherapy treatment employing the cineradiotherapy system 20. It is first necessary to determine the precise geometrical configuration of the tumor volume within the patient to be treated, as well as the position of such tumor volume within the patient's body. This may be accomplished using conventional radiographic methods and reconstruction procedures such as axial transverse multisection radiography and stereosynthesis in order to produce a three dimensional representation of the tumor. Having thus determined the exact volume and configuration of the tumor, a plurality of the radiation shield assemblies 56 are then custom fabricated for treatment of the particular tumor involved. More particularly, the radiation shields 60 are fabricated in accordance with the method disclosed in U.S. Pat. No. 3,937,971 with the cut-out portions 62 therein corresponding to various profiles of the tumor involved as viewed from various points on the circumference of a reference circle lying in a plane passing transversely through the mentioned tumor. Consequently, with respect to the treatment reel 42 disclosed herein having twelve of the radiation shield assemblies 56 mounted thereon, it can be appreciated that the cut-out portion 62 in such shield assemblies 56 correspond to twelve different profiles of the particular tumor to be treated. Similarly, in the event that it is desired to protect a vital, healthy organ in the patient which lies between the source of radiation 86 and the tumor to be treated, a plurality of central radiation absorbers 64 may also be manufactured, in accordance with the method disclosed in U.S. Pat. No. 3,937,971, with the cross-sectional configuration thereof corresponding to the various profiles of such organ, as viewed from various points on the above discussed reference circle lying in the mentioned plane passing transversely through the tumor. Having manufactured both the radiation shield 60 and central radiation absorber 64, each of the latter are mounted, using screws or the like, on the support plate 58 thereby completing fabrication of the radiation shield assembly 56. Each of the radiation shield assemblies 56 are then mounted on the treatment reel 42 in a prescribed, consecutive order, normally corresponding to the order of the view points lying around the circumference of the mentioned reference circle surrounding the tumor.
Each of the radiation shield assemblies 56 is mounted in the corresponding position on the treatment reel 42 by positioning the edges of the support plate 58 within the slots 68 in the front flange 44 on opposite sides of the cut-out portion 66, and the assembly 56 is then slid longitudinally, rearward through the slots 53 until the rear edge of the plate 58 contacts the front side of the rear flange 46, whereupon the shoulder bolts 70 may be inserted into support members 48 whereby to securely hold each of the assemblies 56 in place on the treatment reel 42, in aligned, side-by-side relationship to each other. The above described procedure of mounting the assemblies 56 on the treatment reel 42 may be performed when the latter is removed from the treatment head 36, or alternatively, it may be convenient to first mount the treatment reel 42 on the treatment head 36, as shown in FIG. 3, in order to allow automatic rotation of the reel 42 as the assemblies 56 are successively mounted thereon.
In any event, after each of the assemblies 56 is mounted on the reel 42 and the latter is installed on the treatment head 36 in the manner previously described, the treatment of a tumor volume of tissue in a patient is ready to commence. The patient is first placed on the upper side of the platform 24 of the treatment table 22, with the tumore volume transversely aligned with a vertical plane which will subsequently be traced by the radial axis 94, and axially aligned with the horizontally extending axis 32; for alignment purposes, the position of such tumor volume may be adjusted by laterally or elevationally shifting the platform 24 using mechanism of the treatment table 22 particularly designed for this purpose. With the tumor volume thus aligned at the intersection point 130 of the axes 32 and 94, the gantry 34 is then rotated to a starting position whereat the profile presented by the tumor volume to the source of radiation 86 coincides with the configuration of the cut-out portion 62 in one of the radiation shields 60 mounted on the treatment reel 42. For purposes of the present illustration, let it be assumed that the position of the gantry 34 as depicted in FIG. 1 coincides with the starting position, with the source of radiation 86 vertically aligned above the intersection point 130. With the treatment head 36 rotated to such starting position, motor means 118 is then actuated to rotate the treatment reel 42 with respect to the head 36 until the radiation shield assembly 56 having cut-out portions 62 therein corresponding to such starting position is shifted into a shielding position aligned with the beam opening 92 and interposed between the source of radiation 86 and the tumor volume. At this point, the gantry 34 is rotated in one angular direction toward the next treatment starting position, and the radiation source 86 is activated to produce a prescribed dosage of radiation, which radiation is delivered through the cavity 90 onto the radiation shield 60, which functions, by virtue of the latter's cut-out portions 62, to shape the resulting radiation beam emanating from the treatment head 36, whereby the cross-sectional configuration of the latter conforms to the profile of the tumor presented to the radiation source 86. As radiation is being delivered from the source 86 thereof to the tumor, the central radiation absorber 64, which is of "full thickness" in distinction to prior types thereof, virtually completely shields, and thereby protects, a vital, healthy organ disposed within the path of the radiation beam. After application of the radiation dosage to the first tumor profile and prior to initiating the application of radiation from the second treatment starting position, which coincides with the first treatment ending position, motor means 118 is energized to again rotate treatment reel 42 with respect to head 36 in order to move a second radiation shield assembly 56 into the shielding position aligned with the beam opening 92 between the radiation source and the tumor. Again the gantry 34 is rotated toward the next treatment starting position, and the source 86 is activated to deliver a prescribed dosage to the second treatment profile corresponding to the cut-out portions 62 in a second one of the radiation shields 60, while similarly, a second profile of a healthy organ to be protected is presented to the radiation source 86 which corresponds to the central absorber 64 associated with the mentioned second radiation shield 60. Normally, the radiation shield assemblies 56 will be mounted on the reel 42 in a prescribed order which allows sequential shifting of adjacent shield assemblies 56 into shielding position adjacent the opening 92 as the gantry 34 and head 36 are rotated about the axis 32 to each of the treatment positions. Thus, with respect to the preferred embodiment disclosed herein, it can be appreciated that twelve discrete dosages of radiation are applied to different profiles of the tumor as the treatment head 36 shifts between twelve discrete treatment starting positions around such tumor, in a manner to provide a treatment technique which I have termed "cineradiotherapy". Normally then, treatment of a tumor in a patient is completed upon a complete rotation of the treatment head 36 and one complete revolution of the treatment reel 42. After completion of a radiotherapy treatment session, the treatment reel 42 may be simply removed and placed in storage while another reel may be installed for treatment of the next patient in the manner previously described.
From the foregoing description of the unique method of cineradiotherapy using the novel cineradiotherapy system, it is clearly apparent that the need for complicated mechanism for producing continuous, synchronous shielding of healthy tissues is obviated. Moreover, due to the fact that the specially configured shielding assemblies may be rapidly installed and removed from the cineradiotherapy device, it is apparent that a high volume of patients may be treated with a single cineradiotherapy device, in contrast to the prior art conformation radiotherapy apparatus which required comlex interchange of shielding mechanisms to accommodate sequential treatment of various patients.
The construction details and mode of operation of the cineradiotherapy device have been made amply clear by the foregoing description thereof. Those skilled in the art of conformation radiotherapy will readily appreciate that the novel treatment method disclosed herein may be also practiced by maintaining the radiation source 86 at a fixed location while the patient (and thus the tumor) are rotated with respect to such radiation source 86 to present the various profiles of the tumor to such radiation source. Thus, it is clear the present method may be practiced merely by producing relative rotational motion between the tumor volume and the radiation source.
From the foregoing, it is apparent that the invention provides an effective device implemented method for performing conformation radiotherapy which not only conformally imparts uniform radiation to the volume of tissue defined by the tumor, but also provides enhanced radiation protection of vital, healthy organs disposed within the path of the radiation beam. Thus, it will be observed that the method and apparatus disclosed herein not only provide for the reliable accomplishment of the object of the invention, but do so in a particularly simple and economical manner. It is recognized, of course, that those skilled in the art may make various modifications or additions to the preferred embodiment chosen to illustrate the invention without departing from the gist and essence of this contribution to the art. Accordingly, it is to be understood that the protection sought and to be afforded hereby should be deemed to extend to the subject matter claimed and all equivalents thereof fairly within the scope of the invention.
|"An Examination of Synchronous Shielding in Co-60 Rotational Therapy" by Rawlinson et al., Radiology, vol. 102, pp. 667-671, Mar. 1972.
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|High energy phototherapeutic agents
|Jan 26, 2006
|Mar 31, 2009
|Siemens Medical Solutions Usa, Inc.
|Image-based flat panel alignment
|Dec 1, 2008
|Dec 14, 2010
|Siemens Aktiengesellschaft
|Beam admission unit, beam generation device and tomography device
|Mar 8, 2007
|Jun 25, 2013
|Provectus Pharmatech, Inc.
|Intracorporeal medicaments for high energy phototherapeutic treatment of disease
|Dec 6, 2007
|Oct 15, 2013
|Provectus Pharmatech, Inc.
|Medicaments for chemotherapeutic treatment of disease
|Aug 10, 2010
|Mar 18, 2014
|Varian Medical Systems, Inc.
|Electronic conical collimator verification
|Dec 13, 2011
|Jun 24, 2014
|Varian Medical Systems, Inc.
|Beam filter positioning device
|Aug 15, 2012
|Nov 18, 2014
|Varian Medical Systems, Inc.
|Internally mounted collimators for stereotactic radiosurgery and stereotactic radiotherapy
|Nov 8, 2007
|Mar 10, 2015
|Provectus Pharmatech, Inc.
|Topical medicaments and methods for photodynamic treatment of disease
|May 27, 2016
|Jul 18, 2017
|Michelle Corning
|High energy beam diffraction material treatment system
|Mar 26, 2001
|Jan 3, 2002
|Photogen, Inc.
|Intracorporeal medicaments for high energy phototherapeutic treatment of disease
|Dec 9, 2002
|Sep 4, 2003
|Xantech Pharmaceuticals, Inc.
|Ultrasound contrast using halogenated xanthenes
|Oct 2, 2006
|Apr 5, 2007
|Xantech Pharmaceuticals, Inc.
|Intracorporeal medicaments for high energy phototherapeutic treatment of disease
|Jan 26, 2006
|Jul 26, 2007
|Dieter Manthey
|Image-based flat panel alignment
|Mar 8, 2007
|Sep 6, 2007
|Dees H C
|Intracorporeal medicaments for high energy phototherapeutic treatment of disease
|Nov 8, 2007
|May 22, 2008
|Dees H Craig
|Topical Medicaments and Methods for Photodynamic Treatment of Disease
|Dec 1, 2008
|Jun 4, 2009
|Peter Aulbach
|Beam admission unit, beam generation device and tomography device
|Aug 10, 2010
|Feb 16, 2012
|Dusan Baic
|Electronic conical collimator verification
|U.S. Classification
|378/65, 378/148
|International Classification
|Cooperative Classification
|European Classification


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Okay people it is time for an app that is helpful to our world! i-care is that app. Now you can help those in your community with real issues and not sill posts on social media. Now we can make a difference in our world!!!
Now A word From The Creators of i-care!
I have just launched a mobile app named i-care. It is a community app helping those around you in times of need and also calling upon the community spirit to help you when you also need it. It helps with missing people, pets and items and remains anonymous.
It is truly a beneficial app to have on your phone and it's FREE!
It is truly a beneficial app to have on your phone and it's FREE!
I care....do you?


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- News
Coutts appoints Morley as new chief executive
Coutts & Co. has appointed the former head of Singer and Friedlander's wealth management unit as its new chief executive.
Michael Morley replaces Sarah Deaves, who is moving to become head of affluent banking at RBS UK Retail.
Morley is a seasoned private banker professional having also held senior positions at Barclays Wealth and...
To Read the Full Story, Start Your Free Trial or Sign In


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Business news & features
Sunday 25 May 2003
Unilever's venture capital arm invests in exploring the commercial potential of new ideas. Heather Connon reports.
Telegraph owner Lord Black, whose company Hollinger International is facing a liquidity crisis, is considering dispensing with his two corporate jets to appease shareholders. By Jamie Doward.
Azim Premji is one of the world's richest men and a global tech tycoon. But he has an asceticism inspired by his hero Gandhi, reports Faisal Islam.
Vodafone will this week reveal that it boosted operating profits to about £9bn last year, but that write-downs relating to past acquisitions have pushed it into the red for the second year running.


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Lenovo ThinkPad Laptop Ecoupons: 5/6 to 5/8
This past weekend's Lenovo ThinkPad promotions just ended, but that doesn't mean you've completely missed out. For another couple of days, you can save with the coupon code THINKULTRA. This coupon will get you up to 14% savings off select ThinkPad branded business-class laptops.
New Lenovo Laptop Ecoupons
Current Special Offers For: ThinkPad Laptops
Discounted Models List This Week:
Special Offers Available 5/06 to 5/08
10% off ThinkPad X230 Laptops
14% off ThinkPad X230 Tablets
12% off ThinkPad Tablet 2
$200.00 off ThinkPad T430s Laptops
10% off ThinkPad X1 Carbon Laptops


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Classes, Presentations and Workshops
RIEÛ Parent-Infant/Toddler Guidance Classes in Pasadena:
I offer ongoing Certified RIEÛ Parent-Infant Guidance classes which encourage babies to be attentive, active, exploring and aware of self and others. Designed to encourage children to become authentic and responsible from an early age, Parent-Infant Guidance classes help parents to be confident in their supportive role towards this great discovery. Small groups of parents and babies come together in a relaxing, infant-friendly environment to take pleasure in the infants unfolding development and play. Groups are on-going and remain together in continuous eight-week sessions until the youngest turns two. Whenever possible, infants are grouped according to their stages of motor development. Topics for discussion often include:
Age-appropriate expectations
The importance of play in childrens learning
Balancing parents and childrens needs and wants
Establishing clear, consistent, and appropriate limits
Adapting the home environment as baby grows
Sessions for 2017
Meeting at our new RIEÛ Pasadena Studio:
Wednesday 11:00am Young/Mobile Infants (now forming)
Wednesday 2:00pm Toddlers
Thursday 10:45am Mobile Infants
Thursday 2:00pm Young/Mobile Infants (now forming)
Saturday 3:00pm Older Toddlers
For more information and to register, contact me at:
RIEÛ Foundations: Theory & Observation Courses for Parents & Professionals:
The course provides an overview of the EducaringÛ Approach including psycho-motor, fine motor, social-emotional development of the infant, designing the environment, planning the curriculum, and issues in parenting. This course is designed to enhance the skills and competencies of parents and professionals who work in the field of infant care, teach in a college environment, work with parents, or train students in infant care and development. Participants will actively learn about Magda Gerbers Educaring Approach through lectures, videos, discussions, observations, reading and writing. Each student will be mentored according to his or her goals.
Upcoming Courses:
Washington, DC
August 21 - 30, 2017
Contact Ruth Anne
Los Angeles
September 11 - November 13, 2017
Monday evenings, 6:30-9:30PM and one Saturday (TBD)
Contact the RIE Office at www.RIE.org to register.
Beijing, China
Intensive November 28 - December 8, 2017
Contact Xu Shibo (Amanda) at email@example.com
Phone number :13691430074
Los Angeles
Intensive January 22 - February 2, 2018
Contact the RIE Office at www.RIE.org to register.
New Orleans, Louisiana
June 20 - 29, 2018
Contact Ruth Anne
September 5, 2017 6:30 - 8:30 PM
Evening for Parents & Professionals
Pono School
2002 5th Avenue in Manhattan, New York City
Topic: "Developmental Education" for the Early Years: Why sensitive care and free play are more important than academics.
To register go to link in right column
Other Presentations Available:
Translating Interpersonal Neurobiology to Practice with Infants & Toddlers
Attachment, Caregiving & Self-Regulation
Regulating Aggression in Young Children:
Working with Their Instincts, Not Against Them
Discipline with Respect
Lessons from Infant Mental Health & Neuroscience for Child Care Programs
Teaching by Not Teaching
RIE's Educaring Approach
RIE & Self-Regulation
Respecting Babies - Respecting Adults
Observation: Being Fully Present
How Are Babies & Toddlers Different from Preschoolers?


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Ocean Marine Yacht Club with South Florida's attitude and lifestyle. Enjoy spectacular ocean views.
The towers of DUO located in Hallandale Beach. Just A few blocks to the ocean, and views of Diplomata golf course.
Nnestled between Hollywood Beach and the Intracoastal Waterway, with private docks and ocean access.
Ocean Palms Hollywood Beach is one of the most luxurious condo offerings in the area.
On the sand in Hallandale Beach. Three building complex. Close to shopping, great resturants, Gulf Stream Race Track/casino.
The Diplomat Oceanfront Residences a sleek, chic 28-story residential tower features 135 condominium residences.
This seaside city is no longer a sleepy haven for retirees. Hallandale is encouraging the kind of growth it hasn't seen in decades, with the construction of family oriented condos and townhouses and the increase of small and large businesses. The city's population is getting younger, with a median age of 52. According to the 2000 U.S. census, the percentage of Hallandale Beach residents 65 years and older dropped from 48 percent in 1990 to 35 percent. More than 940 businesses employing 7,000 people now operate in a one-mile radius near the city's center.
A coastal city of over 130,000 residents located in Broward County, Hollywood is nestled between Fort Lauderdale and Miami. Fort Lauderdale-Hollywood International Airport abuts the city, while Port Everglades, the second busiest cruise port in the world, is partially within its municipal boundaries. Interstate 95, the Florida Turnpike, Tri-County Commuter Rail, and two major railroads cut through the city in a north-south direction. Miami International Airport and the Port of Miami are less than twenty-five miles away, providing further opportunities for Hollywood residents and companies to have access to the global marketplace. The region is served by a substantial post-secondary educational infrastructure, including Florida Atlantic University, Florida International University, the University of Miami, a number of smaller private universities and colleges, and a community college system.