ULTRASOUND PHASED ARRAYS

• US 20100022921A1
• Filed: 09/14/2009
• Published: 01/28/2010
• Est. Priority Date: 03/02/2004
• Status: Abandoned Application

• Current Assignee: Narendra T. Sanghvi, Ralf Seip, Wo-Hsing Chen
• Original Assignee: Narendra T. Sanghvi, Ralf Seip, Wo-Hsing Chen
• Inventors: Sanghvi, Narendra T., Seip, Ralf, Chen, Wo-Hsing
• Application Number:
  US12/558,822
• Publication Number:
  US 20100022921A1
• Time in Patent Office: Days
• US Class Current: 601/2
• CPC Class Codes: A61N 2007/0052 using the same transducer for therapy and imaging
• CPC Class Codes: A61N 2007/0065 Concave transducers
• CPC Class Codes: A61N 2007/0078 with multiple treatment transducers
• CPC Class Codes: A61N 2007/0095 by modifying an excitation signal
• CPC Class Codes: A61N 2007/027 with multiple foci created simultaneously
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

Ultrasound transducers are disclosed which focus acoustic energy at various focal locations while minimizing focal spot degradation and the generation of unwanted on-axis or off-axis energy concentrations through using a generally constant f-number at the various focal locations.

Claims

1-22. -22. (canceled)

23. A method of treating tissue with HIFU including a transducer, the method comprising the steps of:

providing HIFU Therapy to a first portion of the tissue, the first portion being located at a first distance from the transducer;

providing HIFU Therapy to a second portion of the tissue, the second portion being located at a second distance from the transducer, the second distance being further from the transducer than the first distance;

maintaining a generally constant f-number with the transducer when providing HIFU Therapy to both the first portion of the tissue and the second portion of the tissue.

24. A transducer for use with HIFU, the transducer, comprising:

an active surface having a plurality of transducer elements; and

a controller operably coupled to the transducer, the controller being configured to select which transducer elements emit acoustic energy and to control such emissions to focus the acoustic energy at various focal depths so that the active surface has a generally constant f-number at the various focal depths.

25. A method for controlling the emission of acoustic energy from a plurality of transducer elements of a multi-element transducer such that the acoustic energy is focused at a desired location, the method comprising the steps of:

determining a phase and an amplitude required for a first transducer element of the plurality of transducer elements;

providing a digital phase input value to a channel operatively coupled to the first transducer element of the plurality of transducer elements;

providing a digital amplitude input value to the channel operatively coupled to the first transducer element of the plurality of transducer elements;

providing a reference continuous wave signal to the channel operatively coupled to the first transducer element;

digitally generating from the reference signal a delayed and pulse-width modulated signal for the first transducer element based on the digital phase input value and the digital amplitude input value;

generating an amplitude modulated analog signal for the first transducer element based on the delayed and pulse-width modulated signal for the first transducer element; and

driving the first transducer element with the amplitude modulated analog signal.

26. The method of claim 25, wherein the amplitude modulated analog signal is generated by filtering of the delayed and pulse-width modulated signal.

27. A method of imaging a targeted tissue and treating portions of the tissue with HIFU Therapy, the method comprising the steps of:

providing a transducer having a longitudinal extent at least equal to a longitudinal extent of the targeted tissue, the transducer including a plurality of individually controlled transducer elements;

electronically scanning a first sub-aperture of the transducer to generate at least one image of the targeted tissue while the transducer is held in place longitudinally, wherein the at least one image is a two-dimensional image including a plurality of line images and at a first scan location the first sub-aperture receives information for a first line image of the two-dimensional image and at a second scan location the first sub-aperture receives information for a second line image;

identifying portions of the targeted tissue for treatment with HIFU Therapy;

treating each of the identified portions of the targeted tissue with HIFU Therapy.

29. The method of claim 27, wherein the first transducer element is driven to produce a continuous wave having a duration in the range of 1 second to 10 seconds and contributing to a total acoustic power at the desired location in the range of about 5 Watts to about 250 Watts.

30. The method of claim 29, wherein the continuous wave has a frequency in the range of 3 MHz to 5 MHz.

28. A method of imaging a targeted tissue and treating portions of the tissue with HIFU Therapy, the method comprising the steps of:

providing a transducer having a longitudinal extent at least equal to a longitudinal extent of the targeted tissue, the transducer including a plurality of individually controlled transducer elements;

electronically scanning a first sub-aperture of the transducer to generate at least one image of the targeted tissue while the transducer is held in place longitudinally, wherein the step of electronically scanning the first sub-aperture, includes the steps of;

activating a first subset of transducer elements proximate to a first side of the transducer;

generating at a first time an acoustic pulse with the first subset transducer elements;

receiving at a second time subsequent to the first time a echo signal reflected back from the targeted tissue with the first subset of transducer elements;

activating a second subset of transducer elements, the second subset being further from the first side than the first subset, the second subset and the first subset being generally the same size;

generating at a third time subsequent to the second time an acoustic pulse with the second subset of transducer elements; and

receiving at a fourth time subsequent to the third time a echo signal reflected back from the targeted tissue with the second subset of transducer elements;

identifying portions of the targeted tissue for treatment with HIFU Therapy;

treating each of the identified portions of the targeted tissue with HIFU Therapy.