US5552707A
Expired / Lapsed
US
⏱️ 0.0 years remaining
RF probe which can vary distance between receiving coils which face each other
Assignee: Hitachi Healthcare Manufacturing Ltd
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Filing: 1994-08-29
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Granted: 1996-09-03
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Expires: 2014-08-29
Abstract
Abstract An RF probe including: two coils for detecting MR signals which are arranged at positions which face each other at a predetermined distance; an apparatus for changing a distance between those coils; and an apparatus for reducing a high frequency coupling between the two coils which is caused due to a change in distance between the coils, in accordance with the distance between the coils.
Inventors
- 👤 Tetsuhiko Takahashi
- 👤 Hiroyuki Takeuchi
- 👤 Yoshikuni Matsunaga
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 16:51
CPC Classifications
G; G01; G01R; G01R33/00; G01R33/20; G01R33/28; G01R33/32; G01R33/34; G01R33/34084; G01R33/34046; G01R33/34061; G01R33/36; G01R33/3642; G01R33/365; G01R33/3628
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
116 words
An RF probe comprising: a first coil and a second coil which are arranged in a magnetostatic field space for independently detecting MR signals emitted from a subject, in which said first and second coils are arranged at positions which face each other at a predetermined distance, each of said first and second coils having an output port for transforming detected MR signals to amplifier means; means for changing the distance between said first and second coil means; and decoupling means for reducing a high frequency coupling between said first and second coils so that a magnitude of reduction of said high frequency coupling changes in accordance with the distance between said first and second coils.
Claim 2
Dependent Claim
116 words
An RF probe comprising: a first coil and a second coil which are arranged in a magnetostatic field space for independently detecting MR signals emitted from a subject, in which said first and second coils are arranged at positions which face each other at a predetermined distance, each of said first and second coils having an output port for transforming detected MR signals to amplifier means; means for changing the distance between said first and second coil means; and decoupling means for reducing a high frequency coupling between said first and second coils so that a magnitude of reduction of said high frequency coupling changes in accordance with the distance between said first and second coils.
Claim 3
Dependent Claim
79 words
An RF probe according to claim 1, wherein said decoupling means for reducing said high frequency coupling includes means for reducing said high frequency coupling by allowing a current to flow in said second coil, said current flowing in said second coil having a level substantially equal to a level of an induced current that is induced in said second coil by said first coil and having a flow direction opposite to a flow direction of said induced current.
Claim 4
Dependent Claim
83 words
An RF probe according to claim 2, wherein said decoupling means for reducing said high frequency coupling includes a third auxiliary coil which is serially connected to said first coil and a fourth auxiliary coil which is serially connected to said second coil and said third and fourth auxiliary coils are arranged at positions so as to be magnetically coupled in a manner such that a degree of said magnetic coupling changes in accordance with the distance between said first and second coils.
Claim 5
Dependent Claim
28 words
An RF probe according to claim 3, wherein said third and fourth auxiliary coils are provided so as to be perpendicular to said first and second coils, respectively.
Claim 6
Dependent Claim
47 words
An RF probe according to claim 4, wherein said third and fourth auxiliary coils have a mutually overlapped portion and an area of said overlapped portion changes in accordance with the distance between said first and second coils, so that the degree of said magnetic coupling changes.
Claim 7
Dependent Claim
26 words
An RF probe according to claim 5, wherein the area of said overlapped portion automatically changes when the distance between said first and second coils changes.
Claim 8
Dependent Claim
63 words
An RF probe according to claim 2, wherein said decoupling means for reducing said high frequency coupling includes an 8-like shaped single auxiliary coil which is electromagnetically coupled to said first and second coils and an intensity of the magnetic coupling between said first and second coils and said auxiliary coil changes in accordance with the distance between said first and second coils.
Claim 9
Dependent Claim
19 words
An RF probe according to claim 1, wherein said first and second coils include a circular or rectangular coil.
Claim 10
Dependent Claim
17 words
An RF probe according to claim 1, wherein said first and second coils include a multiple coil.
Claim 11
Dependent Claim
89 words
An RF probe according to claim 1, wherein said decoupling means for reducing said high frequency coupling includes: means for detecting the distance between said first and second coils; a plurality of capacitive element circuits which are provided so as to be connected in parallel between cables connected to said first and second coils, respectively; and switching means for selecting one of said capacitive element circuits on the basis of an output of said detecting means and for connecting the selected capacitive element circuit in parallel between said cables.
Claim 12
Dependent Claim
71 words
An RF probe according to claim 1, wherein said decoupling means for reducing said high frequency coupling includes: means for detecting the distance between said first and second coils; a capacitive element circuit connected in parallel between cables connected to said first and second coils, respectively; and control means for changing a value of a capacitor of said capacitive element circuit on the basis of an output of said detecting means.
References Cited (Backward Citations)
DE3323657A1
Cited
US4587493A
Cited
US4752738A
Cited
DE3628035A1
Cited
JPH02500175A
Cited
US4825164A
Cited
US4891596A
Cited
JPH01213432A
Cited
EP0338624A1
Cited
DE3905564A1
Cited
EP0412824A2
Cited
US5321360A
Cited
JPH04114633A
Cited
US5196796A
Cited
JPH05154126A
Cited
US5270656A
Cited
US5382903A
Cited
JP2500175B2
Cited
US5389880A
Cited
US5280248A
Cited
DE4325206A1
Cited
US5307806A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-09-03 | 2000-03-04 | 2000-09-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-09-03 | 2004-03-04 | 2004-09-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-09-03 | 2008-03-04 | 2008-09-03 | $7700.00 | Window Closed / Lapsed |