APPARATUS AND METHOD FOR NON-INVASIVE DELIVERY AND TRACKING OF FOCUSED ULTRASOUND GENERATED FROM TRANSDUCER

• US 20110028867A1
• Filed: 07/28/2010
• Published: 02/03/2011
• Est. Priority Date: 07/29/2009
• Status: Abandoned Application

• Current Assignee: Seh-Eun Choo
• Original Assignee: Seh-Eun Choo
• Inventors: Choo, Seh-Eun, Yang, Jae Chun
• Application Number:
  US12/845,210
• Publication Number:
  US 20110028867A1
• Time in Patent Office: Days
• US Class Current: 601/2
• CPC Class Codes: A61B 17/2251 characterised by coupling elements between the apparatus, e.g. shock wave apparatus or locating means, and the patient, e.g. details of bags, pressure control of bag on patient
• CPC Class Codes: A61B 2034/2055 Optical tracking systems
• CPC Class Codes: A61B 8/4281 characterised by sound-transmitting media or devices for coupling the transducer to the tissue
• CPC Class Codes: A61B 90/13 guided by light, e.g. laser pointers
• CPC Class Codes: A61B 90/50 Supports for surgical instruments, e.g. articulated arms
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

The present invention provides an apparatus for non-invasive delivery of focused ultrasound to a targeted area of a biological tissue, and a method thereof. The apparatus comprises an ultrasound wave generator to provide an amplified modulated waveform, a resonance circuit for tuning the waveform to have a predetermined frequency, an ultrasound transducer for generating a focused beam of the tuned waveform, an applicator supporting the ultrasound transducer, and an ultrasound-tissue coupling bag detachably mounted to the ultrasound transducer.

Claims

1. An apparatus for non-invasive delivery of focused ultrasound to a targeted area of a biological tissue, the apparatus comprising:

an ultrasound wave generator (1) which includes an electrical function generator (1A) for generating a continuous current waveform with a specific frequency and a variable voltage amplitude, a pulse modulator (1B) operably connected to the electrical function generator (1A) for modulating amplitude of waveform, and a power amplifier (10) operably connected to the pulse modulator (1B) for amplifying the modulated waveform;

a resonance circuit (3) for tuning the amplified waveform to have a predetermined frequency;

an ultrasound transducer (4) for generating a focused beam of the tuned waveform;

an applicator (5) supporting the ultrasound transducer (4); and

an ultrasound-tissue coupling bag (7) detachably mounted to the ultrasound transducer (4) and holding therein a fluid that has acoustic impedance similar to that of the biological tissue.

2. The apparatus of claim 1, wherein the applicator (5) has a cylindrical shape with the top side open and the ultrasound transducer (4) is received in the open top of the applicator (5).

3. The apparatus of claim 1, further comprising a directional RF coupler (2) between the ultrasound wave generator (1) and the resonance circuit (3), wherein the directional FR coupler (2) is coupled to a power sensor (6) for measuring the electrical power supplied to the ultrasound transducer (4) and that reflected from the resonance circuit (3).

4. The apparatus of claim 1, further comprising at least two markers that allows the focus of the ultrasound transducer (4) to be detected and tracked in space.

5. The apparatus of claim 4, further comprising at least two MRI-CT markers (81), wherein the two MRI-CT markers (81) are spaced from each other by a predetermined distance and are spaced from the focus of the ultrasound transducer (4) by a predetermined distance such that the MRI-CT markers (81) and the focus are defined on an imaginary straight line.

6. The apparatus of claim 4, further comprising at least three infrared reflection (IR) markers (9), wherein the IR markers are positioned on an imaginary plane and the center of the IR markers and the sonication focus (F) are on an imaginary straight line forming a predetermined angle with the plane.

7. The apparatus of claim 6, wherein the predetermined angle is 90°

or substantially 90°

.

8. The apparatus of claim 6, further comprising at least two MRI-CT markers (81), wherein the two MRI-CT markers (81) are spaced from each other by a predetermined distance and are spaced from the focus of the ultrasound transducer (4) by a predetermined distance such that the MRI-CT markers (81) and the focus are defined on an imaginary straight line.

9. The apparatus of claim 1, further comprising at least two laser beam generators (111A, 111B), each of which is connected to a corresponding pivoting adapter (112A, 112B) that is attached to the applicator (5) for allowing the laser beam generators to be pivotably moved.

10. The apparatus of claim 9, further comprising further comprising at least two MRI-CT markers (81), wherein the two MRI-CT markers (81) are spaced from each other by a predetermined distance and are spaced from the focus of the ultrasound transducer (4) by a predetermined distance such that the MRI-CT markers (81) and the focus are defined on an imaginary straight line.

11. The apparatus of claim 9, further comprising at least three infrared reflection (IR) markers (9), wherein the IR markers are positioned on an imaginary plane and the center of the IR markers and the sonication focus (F) are on an imaginary straight line forming a predetermined angle with the plane.

12. The apparatus of claim 11, further comprising further comprising at least two MRI-CT markers (81), wherein the two MRI-CT markers (81) are spaced from each other by a predetermined distance and are spaced from the focus of the ultrasound transducer (4) by a predetermined distance such that the MRI-CT markers (81) and the focus are defined on an imaginary straight line.

13. The apparatus of claim 1, wherein the applicator is mounted to a moving stage.

14. A method for non-invasive delivery of focused ultrasound to modify a biological activity of the brain of a subject, the method comprising the steps of:

positioning a ultrasound transducer on or near a portion of the head of a subject;

generating a ultrasound waveform (continuous current waveform);

modulating the amplitude of the waveform;

amplifying the modulated waveform;

tuning the amplified modulated waveform to have a predetermined frequency;

focusing the modulated waveform on a predetermined focal point; and

adjusting the strength of the focused waveform and the position of the focal point.

17. The method of claim 14, wherein in the step of adjusting, the strength is adjusted to be between 1-65 Watt/cm² (Spatial peak pulse averaged), at a rate of 1 to 2000 Hz with the pulse duration of 1-100 msec, with total sonication duration less than 2 sec.

18. The method of claim 14, wherein in the step of adjusting, the strength is adjusted to be between 1-50 Watt/cm² (Spatial peak pulse averaged), at a rate of 100 to 2000 Hz with the pulse duration of less than 1 msec, for the duration more than 2 sec.

19. The method of claim 14, further comprising a step of visualizing the focus in an MRI or CT image in which the brain of a subject is shown.

15. The method of clam 14, further comprising the step of detachably mounting an ultrasound-tissue coupling bag containing degassed water and applying a hydrogel on the both sides of the bag.

16. The method of clam 14, wherein in the step of tuning, the amplified modulated waveform is tuned for the range of 200 kHz-700 Khz.