Dual mode ultrasound transducer (DMUT) system and method for controlling delivery of ultrasound therapy

Patent metadata

Field	Value
Publication number	US-11076836-B2
Application number	US-201916262138-A
Country	US
Kind code	B2
Filing date	Jan 30, 2019
Priority date	Jun 9, 2010
Publication date	Aug 3, 2021
Grant date	Aug 3, 2021

Abstract

A dual-mode ultrasound system provides real-time imaging and therapy delivery using the same transducer elements of a transducer array. The system may use a multi-channel driver to drive the elements of the array. The system uses a real-time monitoring and feedback image control of the therapy based on imaging data acquired using the dual-mode ultrasound array (DMUA) of transducer elements. Further, for example, multi-modal coded excitation may be used in both imaging and therapy modes. Still further, for example, adaptive, real-time refocusing for improved imaging and therapy can be achieved using, for example, array directivity vectors obtained from DMUA pulse-echo data.

First claim

The invention claimed is:

1. A dual mode ultrasound transducer system comprising:
an array of ultrasound transducer elements, the ultrasound transducer elements configured to deliver one or more therapy shots, each therapy shot comprising a plurality of sequential therapy bursts of ultrasonic energy to at least a portion of a target region and to transmit/receive imaging ultrasonic energy to/from the target region; and
a control apparatus comprising at least one processor configured to:
control conveyance of imaging signals to/from one or more of the array of ultrasound transducer elements;
generate treatment region image data usable to identify at least one or more target points within a target region based on imaging signals conveyed to/from one or more of the array of ultrasound elements;
generate therapy signals to drive one or more of the array of ultrasound transducer elements to deliver a plurality of sequential therapy bursts of ultrasonic energy to at least one of the one or more target points in the target region, wherein each of the sequential therapy bursts is defined to produce a response at one or more target points within the target region, wherein the therapy bursts are spaced by a duration of less than 10 milliseconds;
generate control image data based on imaging signals from one or more of the array of ultrasound transducer elements;
estimate a cavitation threshold in situ at the one or more target points using an estimated focal pressure and treatment region image data; and
design therapeutic pulses to be generated based on the estimated focal pressure and treatment region image data.

2. The system of claim 1 , wherein the control apparatus is further configured to use multi-modal coded excitation with multiple-focus synthesis.

3. The system of claim 1 , wherein the control apparatus is further configured to perform cavitation-based thermal treatment using the estimated cavitation threshold at each target point.

4. The system of claim 1 , wherein the control apparatus is further configured to use a dynamic power reallocation algorithm to adaptively determine power directed to the one or more target points.

5. The system of claim 1 , wherein the control apparatus is further configured to use image-based calibration of thermal response to therapy beams at sub-therapeutic levels and with sub-second durations to calculate calibrated exposure in situ for each therapy shot.

6. The system of claim 1 , wherein the control apparatus is further configured to initiate cavitation events to achieve thermal coagulation or interrogate tissue response.

7. The system of claim 1 , wherein the control apparatus is further configured to:
identify a vessel wall using control image data;
identify a boundary of the vessel wall; and
define therapy signals to minimize power at one or more critical points including the vessel wall.

8. The system of claim 1 , wherein the control apparatus is further configured to use vascular imaging to measure blood flow through at least one portion of a blood vessel.

9. The system of claim 1 , wherein the control apparatus is further configured to:
use multiple-focus synthesis to provide a heating pattern to a target region in which a blood vessel is located; and
define one or more critical points corresponding to the blood vessel.

10. The system of claim 1 , wherein the control apparatus is further configured to generate treatment region image data usable to identify one or more critical points representative of intervening tissue located between the array of ultrasound elements and the one or more target points within the target region based on imaging signals conveyed to/from one or more of the array of ultrasound elements.

11. The system of claim 10 , wherein, to generate at least one imaging signal to drive one or more of the array of ultrasound transducer elements to transmit at least one focused single transmit energy pulse, the control apparatus is further configured to:
generate imaging signals to drive one or more of the array of ultrasound transducer elements to transmit sequential single transmit energy pulses focused to each of a plurality of one or more target points within the target region and/or one or more critical points resulting in pulse-echo data to be captured; or
use coded excitation to generate at least one imaging signal to drive one or more of the array of ultrasound transducer elements to transmit at least one single transmit energy pulse focused to one or more target points within the target region and/or one or more critical points resulting in pulse-echo data to be captured.

12. The system of claim 1 , wherein, prior to delivery of a subsequent therapy burst of the plurality of sequential therapy bursts at therapeutic levels based on therapy signals generated using control image data generated during and/or following delivery of a previous therapy burst, the control apparatus is further configured to:
control a test of the subsequent therapy burst at sub-therapeutic levels; and
optionally modify therapy signals generated to deliver the subsequent therapy burst based on imaging results from the test.

13. The system of claim 1 , wherein, to generate control image data during and/or following delivery of each therapy burst of a plurality of sequential therapy bursts, the control apparatus is further configured to generate control image data comprising at least one of displacement and/or strain data, directivity data, thermal response data, and data indicative of cavitation for use in generating therapy signals to drive one or more of the array of ultrasound transducer elements to deliver a subsequent therapy burst of the plurality of sequential therapy bursts.

14. The system of claim 1 , wherein the system further comprises a display apparatus to display image data and a user interface to allow a user to input one or more commands for real-time control of the delivery of the plurality of sequential therapy bursts, and optionally the user interface is configured to allow a user to select at least one or more target points and/or one or more critical points for use in controlling delivery of the plurality of sequential therapy bursts.

15. The system of claim 1 , wherein, to generate control image data, the control apparatus is further configured to generate data based at least in part on imaging performed at least in part during delivery of one or more therapy bursts using coded excitation, or for use in controlling one or more characteristics of the plurality of therapy bursts, wherein the one or more characteristics comprise at least one of phase/delay, amplitude, and spectral content.

16. A dual mode ultrasound transducer system comprising:
an array of ultrasound transducer elements, the ultrasound transducer elements configured to deliver one or more therapy shots, each therapy shot comprising a plurality of sequential therapy bursts of ultrasonic energy to at least a portion of a target region and to transmit/receive imaging ultrasonic energy to/from the target region; and
a control apparatus comprising:
means for controlling conveyance of imaging signals to/from one or more of the array of ultrasound transducer elements;
means for generating treatment region image data usable to identify at least one or more target points within a target region based on imaging signals conveyed to/from one or more of the array of ultrasound elements;
means for generating therapy signals to drive one or more of the array of ultrasound transducer elements to deliver a plurality of sequential therapy bursts of ultrasonic energy to at least

Assignees

• Univ Minnesota

Inventors

• Ebbini Emad S
• Casper Andrew J
• Liu Dalong
• Ballard John R

Classifications

• A61B8/4488 Primary

  the transducer being a phased array · CPC title

• A61N2007/0082

  Scanning transducers · CPC title

• A61N2007/0095

  by modifying an excitation signal · CPC title

• A61N7/02 Primary

  Localised ultrasound hyperthermia · CPC title

• G01S7/5202

  for pulse systems · CPC title