Patent US6309355B1 successfully refreshed from Google Patents.
US6309355B1
Expired / Lapsed
US
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Method and assembly for performing ultrasound surgery using cavitation
Assignee: University of Michigan (System)
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Filing: 1998-12-22
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Granted: 2001-10-30
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Expires: 2018-12-22
Abstract
Abstract A method and assembly are provided which use cavitation induced by an ultrasound beam for creating a controlled surgical lesion in a selected treatment volume of a patient. First, a plurality of microbubbles are provided in the treatment volume. Preferably, the threshold for cavitation of microbubbles in the treatment volume is lowered compared with the threshold for cavitation in surrounding tissues. The expected location of the surgical lesion within the treatment volume may be previewed, and then the microbubbles in the treatment volume are cavitated with the ultrasound beam to create the controlled surgical lesion. Preferably, the creation of the surgical lesion at the expected lesion location is then verified. Using the method and assembly of the present invention, the cavitation threshold within the treatment volume is made predictable, and a low frequency ultrasound beam may be used to cavitate the microbubbles within the treatment volume without causing damage to surrounding tissues.
Inventors
- 👤 Charles A. Cain
- 👤 J. Brian Fowlkes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:40
CPC Classifications
A; A61; A61N; A61N7/00; A61B; A61B17/00; A61B17/22; A61B17/22004; A61M; A61M37/00; A61M37/0092; A61B2017/22005; A61B2017/22007; A61B2017/22008; A61B2017/22082; A61B2017/22089; A61N2007/0039; A61N2007/0086; A61N2007/0095
Claims Analysis
Total Claims: 25
Claim 1
Independent Claim
99 words
A method for creating a surgical lesion in a selected treatment volume of a patient, the method comprising: providing a plurality of microbubbles in the treatment volume and in a volume external to the treatment volume, the microbubbles having a threshold for cavitation; controlling the microbubbles in the external volume to create a differential threshold for cavitation between the external volume and the treatment volume; and cavitating the plurality of microbubbles in the treatment volume with an ultrasound beam of sufficient energy at an appropriate frequency to create the surgical lesion in a controlled manner within the treatment volume.
Claim 2
Independent Claim
99 words
A method for creating a surgical lesion in a selected treatment volume of a patient, the method comprising: providing a plurality of microbubbles in the treatment volume and in a volume external to the treatment volume, the microbubbles having a threshold for cavitation; controlling the microbubbles in the external volume to create a differential threshold for cavitation between the external volume and the treatment volume; and cavitating the plurality of microbubbles in the treatment volume with an ultrasound beam of sufficient energy at an appropriate frequency to create the surgical lesion in a controlled manner within the treatment volume.
Claim 3
Dependent Claim
17 words
The method of claim 1 , wherein the frequency of the ultrasound beam is a low frequency.
Claim 4
Dependent Claim
45 words
The method of claim 1 , further comprising lowering the threshold for cavitation of microbubbles in the treatment volume by producing a population of microbubbles within the treatment volume which have a limited size distribution, so that the microbubbles oscillate at a maximal response frequency.
Claim 5
Dependent Claim
15 words
The method of claim 3 , wherein the maximal response frequency is a low frequency.
Claim 6
Dependent Claim
25 words
The method claim 1 , wherein controlling the microbubbles in the external volume comprises eliminating microbubbles from the external volume with low intensity ultrasound beam.
Claim 7
Dependent Claim
20 words
The method of claim 1 , wherein providing the plurality of microbubbles includes injecting the microbubbles into the patient systemically.
Claim 8
Dependent Claim
21 words
The method of claim 1 , wherein providing the plurality of microbubbles includes injecting the microbubbles locally into the treatment volume.
Claim 9
Dependent Claim
23 words
The method of claim 1 , wherein providing the plurality of microbubbles includes providing an admixture of microbubbles having populations with differing properties.
Claim 10
Dependent Claim
39 words
The method of claim 8 , wherein providing an admixture of microbubbles includes providing a first population that responds primarily to high intensity ultrasound fields in combination with a second population that responds primarily to low intensity ultrasound fields.
Claim 11
Dependent Claim
23 words
The method of claim 1 , wherein providing the plurality of microbubbles comprises creating the plurality of microbubbles with a preliminary ultrasound beam.
Claim 12
Dependent Claim
17 words
The method of claim 1 , further comprising detecting the presence of microbubbles in the treatment volume.
Claim 13
Dependent Claim
31 words
The method of claim 11 , wherein detecting the presence of microbubbles in the treatment volume uses harmonic imaging to determine the particular size distribution of microbubbles in the treatment volume.
Claim 14
Dependent Claim
20 words
The method of claim 1 , further comprising previewing an expected location of the surgical lesion within the treatment volume.
Claim 15
Dependent Claim
43 words
The method of claim 13 , wherein previewing the expected location of the surgical lesion includes directing a low intensity ultrasound beam at the treatment volume so as to collapse microbubbles at the focus of the beam, thereby indicating the expected lesion location.
Claim 16
Dependent Claim
40 words
The method of claim 13 , wherein previewing the expected location of the surgical lesion includes briefly directing a high intensity ultrasound beam at the treatment volume to cause increased cavitation of the microbubbles, thereby indicating the expected lesion location.
Claim 17
Dependent Claim
12 words
The method of claim 1 , wherein the ultrasound beam is focused.
Claim 18
Dependent Claim
12 words
The method of claim 1 , wherein the ultrasound beam is unfocused.
Claim 19
Dependent Claim
20 words
The method of claim 1 , wherein providing the plurality of microbubbles includes providing an admixture of microbubbles and drugs.
Claim 20
Dependent Claim
18 words
The method of claim 1 , wherein cavitating the microbubbles releases drugs encapsulated therein within the treatment volume.
Claim 21
Dependent Claim
20 words
The method of claim 1 , further comprising verifying the creation of the surgical lesion at an expected lesion location.
Claim 22
Dependent Claim
34 words
The method of claim 20 , wherein verifying the creation of the surgical lesion includes providing new microbubbles in the treatment volume and monitoring the presence or absence thereof at the expected lesion location.
Claim 23
Dependent Claim
28 words
The method of claim 1 , wherein controlling the microbubbles in the external volume includes reducing the cavitation potential in the external volume compared with the treatment volume.
Claim 24
Independent Claim
125 words
A method for using cavitation induced by an ultrasound beam to create a controlled surgical lesion in a selected treatment volume of a patient, the method comprising: providing a plurality of microbubbles in the treatment volume and in a volume external to the treatment volume, the microbubbles having a threshold for cavitation; detecting the presence of microbubbles in the treatment volume; controlling the microbubbles in the external volume to create a differential threshold for cavitation between the external volume and the treatment volume; previewing an expected location of the surgical lesion within the treatment volume; cavitating the microbubbles in the treatment volume with the ultrasound beam to create the controlled surgical lesion; and verifying the creation of the surgical lesion at the expected lesion location.
Claim 25
Independent Claim
125 words
A method for using cavitation induced by an ultrasound beam to create a controlled surgical lesion in a selected treatment volume of a patient, the method comprising: providing a plurality of microbubbles in the treatment volume and in a volume external to the treatment volume, the microbubbles having a threshold for cavitation; detecting the presence of microbubbles in the treatment volume; controlling the microbubbles in the external volume to create a differential threshold for cavitation between the external volume and the treatment volume; previewing an expected location of the surgical lesion within the treatment volume; cavitating the microbubbles in the treatment volume with the ultrasound beam to create the controlled surgical lesion; and verifying the creation of the surgical lesion at the expected lesion location.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 2004-10-29 | 2005-04-30 | 2005-10-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2008-10-29 | 2009-04-30 | 2009-10-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2012-10-29 | 2013-04-30 | 2013-10-30 | $7700.00 | Window Closed / Lapsed |