Boiling histotripsy methods and systems for uniform volumetric ablation of an object by high-intensity focused ultrasound waves with shocks

Patent metadata

Field	Value
Publication number	US-12157018-B2
Application number	US-201916712680-A
Country	US
Kind code	B2
Filing date	Dec 12, 2019
Priority date	Mar 28, 2014
Publication date	Dec 3, 2024
Grant date	Dec 3, 2024

Abstract

An example method includes generating an acoustic ultrasound wave that is focused at a focal point. The method further includes sequentially directing the focal point upon distinct portions of an object to form respective shock waves at the distinct portions of the object. The method further includes, via the respective shock waves, causing the distinct portions of the object to boil and form respective vapor cavities. The method further includes causing substantially uniform ablation of a region of the object that comprises the distinct portions. The substantially uniform ablation is caused via interaction of the respective shock waves with the respective vapor cavities. An example ablation system and an example non-transitory computer-readable medium, both related to the example method, are also disclosed.

First claim

The invention claimed is:

1. A method comprising:
determining a trajectory based on characteristics of an object in tissue and a size of a focal point associated with an ultrasound transducer array, the trajectory including a first layer and a second layer set at different depths in the tissue;
generating, using the ultrasound transducer array, an acoustic ultrasound wave that is focused at the focal point;
directing the focal point upon a first portion of the object in the first layer to form first shock waves at the first portion, thereby applying a first ultrasound dose to the first portion and causing the first portion to boil and form a first vapor cavity via the first shock waves, wherein the first ultrasound dose is defined by a first quantity of first ultrasound pulses, a first amplitude of the first shock waves, a first oscillation frequency of the first ultrasound pulses, a first pulse duration of the first ultrasound pulses, and a first duty cycle of the first ultrasound pulses, and a first pulse repetition frequency that is greater than or equal to 4 Hz and less than or equal to 15 Hz; and
directing the focal point upon each second portion of a plurality of second portions of the object according to the trajectory in which the focal point is sequentially directed among second portions that are adjacent to second portions, to form second shock waves at each second portion of the plurality, thereby applying a second ultrasound dose to each second portion of the plurality, wherein at least one second portion of the plurality of second portions is in the second layer,
wherein the second ultrasound dose is defined by a second quantity of second ultrasound pulses that is substantially equal to the first quantity, a second amplitude of the second shock waves that is substantially equal to the first amplitude, a second pulse duration that is substantially equal to the first pulse duration, a second oscillation frequency that is substantially equal to the first oscillation frequency, a second duty cycle that is substantially equal to the first duty cycle, and a second pulse repetition frequency that is substantially equal to the first pulse repetition frequency, and causing each second portion of the plurality to boil and form a second vapor cavity via the second shock waves, wherein the plurality of second portions are distinct from each other and from the first portion.

2. The method of claim 1 , wherein the tissue is a biological object tissue within a living organism.

3. The method of claim 2 , wherein the biological tissue is selected from a group consisting of a brain tissue, a nerve tissue, a liver tissue, a kidney tissue, a muscle tissue, a fat tissue, a connective tissue, a tumor, a hematoma, an abscess, a lipoma, a diseased tissue, and an undesirable tissue.

4. The method of claim 1 , wherein the first oscillation frequency is greater than 900 kHz and less than 20 MHz.

5. The method of claim 1 , wherein the first pulse duration is greater than 0.1 millisecond and less than or equal to 40 milliseconds.

6. The method of claim 1 , wherein the first quantity is greater than 5 and less than about 200.

7. The method of claim 1 , wherein the first portion and the plurality of second portions are not colinear and/or not coplanar.

8. The method of claim 7 , wherein the first portion and the plurality of second portions form one or more concentric circles and/or one or more concentric spheres.

9. The method of claim 1 , wherein causing the first portion of the object to boil and form the first vapor cavity comprises heating the first portion to at least 100° C.

10. The method of claim 1 , wherein determining the trajectory comprises:
capturing an image of the object; and
determining the trajectory that includes the first portion and the plurality of second portions based on the image,
wherein the focal point is directed upon the first portion and the plurality of second portions according to the trajectory determined based on the image.

11. The method of claim 10 , the method further comprising:
determining the size, a shape, or a location of the object based on the image; and
apportioning the object into the first portion and the plurality of second portions based on the size, the shape, or the location.

12. The method of claim 1 , further comprising:
receiving input representing one or more parameters for generating the acoustic ultrasound wave or directing the focal point,
wherein the acoustic ultrasound wave is generated and/or directed according to the input.

13. A non-transitory computer-readable medium storing instructions that, when executed by an ablation system, cause the ablation system to perform the method of claim 1 .

14. The method of claim 1 , wherein applying the first ultrasound dose to the first portion and applying the second ultrasound dose to the plurality of second portions comprises causing substantially uniform ablation of the first portion and the plurality of second portions.

15. The method of claim 14 , wherein causing the substantially uniform ablation of the first portion and the plurality of second portions comprises causing mechanical ablation of the first portion and the plurality of second portions.

16. An ablation system configured to ablate an object, the ablation system comprising:
one or more processors;
a sensor module configured to collect sensory data from the object during ablation;
an input/output interface configured to receive user input and display an image representing the sensory data;
an ablation module configured to generate an acoustic ultrasound wave and sequentially direct a focal point of the acoustic ultrasound wave upon distinct portions of the object; and
a non-transitory computer-readable medium storing instructions that, when executed by the one or more processors, cause the ablation system to perform the method of claim 1 .

17. The method of claim 1 , wherein directing the focal point comprises directing the focal point via electronic steering of an array of transducer elements.

18. The method of claim 1 , wherein the first amplitude is at least 40 MPa, wherein the first duty cycle is greater than 0.5% and less than 12%, wherein a volume of the first portion is greater than 0.1 mm 3 and less than 0.5 mm 3 , wherein a volume of each second portion of the plurality is greater than 0.1 mm 3 and less than 0.5 mm 3 , and wherein a total volume of the first portion and the plurality of second portions is at least 1 cm 3 .

19. The method of claim 1 , wherein determining the trajectory comprises dividing the object into a plurality of distinct portions comparable in size to the focal point.

20. The method of claim 1 , wherein the first layer and the second layer are separated by about 5 mm.

21. The method of claim 1 , wherein the first layer defines a first pattern and the second layer defines a second pattern, wherein the second pattern is different than the first pattern.

Assignees

• Univ Washington
• Koninklijke Philips N V A Corporporation Organized And Existing Under The Laws Of Kingdom Of The Net

Inventors

• Khokhlova Vera
• Bailey Michael R
• Farr Navid
• Khokhlova Tatiana D
• Kreider Wayne
• Maxwell Adam D
• Partanen Ari
• Sapozhnikov Oleg A
• Schade George R
• Wang Yak-Nam

Classifications

• A61B2017/22007

  Cavitation or pseudocavitation, i.e. creation of gas bubbles generating a secondary shock wave when collapsing · CPC title

• A61B17/22004

  using mechanical vibrations, e.g. ultrasonic shock waves (A61B17/225 takes precedence) · CPC title

• A61N7/02 Primary

  Localised ultrasound hyperthermia · CPC title