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US5694936A Expired / Lapsed US ⏱️ 0.0 years remaining

Ultrasonic apparatus for thermotherapy with variable frequency for suppressing cavitation

Assignee: Toshiba Corp
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Filing: 1995-09-14
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Granted: 1997-12-09
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Expires: 2015-09-14
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Abstract

Abstract An ultrasonic diagnosis apparatus for raising tissue temperature for hypothermic treatments, including an ultrasonic source for generating an ultrasonic treatment wave and a driving means for driving the ultrasonic source such that a frequency of the ultrasonic treatment wave generated by the ultrasonic source changes with time. The frequency of the ultrasonic treatment wave is changed along the time axis. By this change in frequency, some bubbles formed by cavitation as a result of the ultrasonic treatment wave are divided, and some bubbles are collapsed and therefore eliminated. Side effect cavitation and spread of a thermal degeneration area is suppressed, and thermal degeneration can be accurately induced in a desired area, thereby realizing a reliable, safe ultrasonic thermotherapy. Since cavitation is positively suppressed, the total treatment period can be shortened because cavitation would otherwise interfere with and slow down the thermal degeneration process. Therefore, treatment throughput can be improved as compared with a case in which cavitation is left to naturally break and disappear.

Inventors

  • 👤 Katsuhiko Fujimoto
  • 👤 Yoshiharu Ishibashi
  • 👤 Mariko Shibata
  • 👤 Takuji Suzuki
  • 👤 Satoshi Aida
  • 👤 Shiroh Saitoh
  • 👤 Kazuya Okamoto

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-23 18:42
CPC Classifications
A; A61; A61N; A61N7/00; A61N7/02; A61B; A61B17/00; A61B2017/00017; A61B2017/00137; A61B2017/00154; A61B2017/00172; A61B2017/00176; A61B17/22; A61B17/22004; A61B2017/22005; A61B2017/22007; A61B2017/22009; A61N2007/0056; A61N2007/0065; A61N2007/0073

Claims Analysis

Total Claims: 25
Claim 1
Independent Claim 53 words
An ultrasonic treatment apparatus for raising tissue temperature for thermotherapy treatments, comprising: an ultrasonic source for generating an ultrasonic treatment wave; and driving means for driving said ultrasonic source such that a frequency of the ultrasonic treatment wave generated by said ultrasonic source changes along a time axis such that cavitation is suppressed.
Claim 2
Dependent Claim 53 words
An ultrasonic treatment apparatus for raising tissue temperature for thermotherapy treatments, comprising: an ultrasonic source for generating an ultrasonic treatment wave; and driving means for driving said ultrasonic source such that a frequency of the ultrasonic treatment wave generated by said ultrasonic source changes along a time axis such that cavitation is suppressed.
Claim 3
Dependent Claim 33 words
An apparatus according to claim 1, wherein said driving means includes driving signal generating means for generating a driving signal to said ultrasonic source and means for controlling said driving signal generating means.
Claim 4
Dependent Claim 49 words
An apparatus according to claim 1, wherein said driving means modulates an amplitude of a driving signal in accordance with the frequency of the ultrasonic treatment wave such that an output level of the ultrasonic treatment wave generated by said ultrasonic source is kept at a substantially constant level.
Claim 5
Dependent Claim 23 words
An apparatus according to claim 1, wherein the frequency of the ultrasonic treatment wave changes from a low frequency to a high frequency.
Claim 6
Dependent Claim 28 words
An apparatus according to claim 1, wherein the frequency of the ultrasonic treatment wave repeatedly changes at a period within a range of 500 μs to 50 ms.
Claim 7
Dependent Claim 63 words
An apparatus according to claim 1, wherein said driving means drives said ultrasonic source such that a first interval in which the frequency of the ultrasonic treatment wave is fixed to a specific frequency and a second interval in which the frequency of the ultrasonic treatment wave changes along the time axis; and said driving means alternates between said first and second interval.
Claim 8
Dependent Claim 26 words
An apparatus according to claim 6, wherein the specific frequency is set to a resonance frequency of at least one ultrasonic element of said ultrasonic source.
Claim 9
Dependent Claim 32 words
An apparatus according to claim 6, wherein the frequency of the ultrasonic treatment wave repeatedly changes at a period within a range of 500 μs to 50 ms in the second interval.
Claim 10
Dependent Claim 20 words
An apparatus according to claim 6, wherein the second interval is set not more than three times the first interval.
Claim 11
Dependent Claim 55 words
An apparatus according to claim 6, wherein the second interval is set not less than three times the first interval and not more than 10 times the first interval, and the frequency of the ultrasonic treatment wave repeatedly changes at a period within a range of 500 μs to 50 ms in the second interval.
Claim 12
Dependent Claim 30 words
An apparatus according to claim 1, wherein the frequency of the ultrasonic treatment wave changes within a range of at least 20% the resonance frequency unique to said ultrasonic source.
Claim 13
Dependent Claim 75 words
An apparatus according to claim 1, further comprising: means for scanning a slice of a target object with an ultrasonic beam to repeatedly generate ultrasonic images on the basis of resultant reception signals; difference means for obtaining a difference between two ultrasonic frame images generated at different times; and means for counting, on the basis of a difference result from said difference means, timings at which the frequency of the ultrasonic treatment wave is changed.
Claim 14
Dependent Claim 29 words
The apparatus according to claim 1, wherein said driving means changes said frequency to break at least part of bubbles which appear with generation of said ultrasonic treatment wave.
Claim 15
Dependent Claim 26 words
The apparatus according to claim 1, further comprising an imaging probe for transmitting an ultrasonic wave for imaging, and for receiving an echo from a subject.
Claim 16
Dependent Claim 38 words
An ultrasonic treatment apparatus comprising: an ultrasonic source for generating an ultrasonic treatment wave; and driving means for driving said ultrasonic source such that a phase of the ultrasonic treatment wave generated by said ultrasonic source is modulated.
Claim 17
Dependent Claim 38 words
An ultrasonic treatment apparatus comprising: an ultrasonic source for generating an ultrasonic treatment wave; and driving means for driving said ultrasonic source such that a phase of the ultrasonic treatment wave generated by said ultrasonic source is modulated.
Claim 18
Dependent Claim 17 words
An apparatus according to claim 15, wherein the phase of the ultrasonic treatment wave is intermittently inverted.
Claim 19
Dependent Claim 75 words
An apparatus according to claim 15, further comprising: means for scanning a slice of a target object with an ultrasonic beam to repeatedly generate ultrasonic images on the basis of resultant reception signals; difference means for obtaining a difference between two ultrasonic frame images generated at different times; and means for counting, on the basis of a difference result from said difference means, timings at which the phase of the ultrasonic treatment wave is modulated.
Claim 20
Dependent Claim 48 words
An ultrasonic treatment apparatus comprising: a first ultrasonic source for generating an ultrasonic treatment wave; a second ultrasonic source for generating an ultrasonic cavitation destruction wave having a frequency higher than that of the ultrasonic treatment wave; and driving means for driving said first and second ultrasonic sources.
Claim 21
Dependent Claim 48 words
An ultrasonic treatment apparatus comprising: a first ultrasonic source for generating an ultrasonic treatment wave; a second ultrasonic source for generating an ultrasonic cavitation destruction wave having a frequency higher than that of the ultrasonic treatment wave; and driving means for driving said first and second ultrasonic sources.
Claim 22
Dependent Claim 43 words
An apparatus according to claim 18, wherein said first and second ultrasonic sources are formed in a spherical pattern as a whole, said second ultrasonic source is located near the center, and said first ultrasonic source is located around said second ultrasonic source.
Claim 23
Dependent Claim 44 words
An apparatus according to claim 18, wherein the ultrasonic treatment wave is generated by a first piezoelectric layer, and the ultrasonic cavitation destruction wave is generated by simultaneously driving said first piezoelectric layer and a second piezoelectric layer stacked on said first piezoelectric layer.
Claim 24
Dependent Claim 18 words
An apparatus according to claim 18, wherein said driving means alternatively drives said first and second ultrasonic generators.
Claim 25
Dependent Claim 18 words
An apparatus according to claim 18, wherein said driving means simultaneously drives said first and second ultrasonic sources.

References Cited (Backward Citations)

US5150711A Cited
US4689986A Cited
US5247935A Cited
US5368032A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 2000-12-08 2001-06-09 2001-12-09 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 2004-12-08 2005-06-09 2005-12-09 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2008-12-08 2009-06-09 2009-12-09 $7700.00 Window Closed / Lapsed

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