Ultra sound hyperthermia device

• US 4,646,756 A
• Filed: 10/24/1983
• Issued: 03/03/1987
• Est. Priority Date: 10/26/1982
• Status: Expired due to Fees

• Current Assignee: Aberdeen The University of, Carlton Medical Products Limited (Cancer Research UK)
• Original Assignee: Carlton Medical Products Limited (Cancer Research UK), University of Aberdeen
• Inventors: Watmough, David J., Hynynen, Kullevro, Mallard, John R.
• Primary Examiner(s): Coven, Edward M.
• Assistant Examiner(s): HINDENBURG, MAX F
• Application Number:
  US06/544,820
• Time in Patent Office: 1,226 Days
• Field of Search: 128/24 A, 128/76.5, 128/422, 128/660, 128/661, 128/804
• US Class Current: 607/154
• CPC Class Codes: A61B 2017/00084 Temperature
• CPC Class Codes: A61B 2017/22028 arrays, e.g. phased arrays
• CPC Class Codes: A61N 7/02 Localised ultrasound hyperthermia hyperthermia in general A61F7/00

Abstract

An ultrasound unit for the clinical application of hyperthermia to tumor cells in soft tissue. The ultrasound hyperthermic unit includes in one aspect an array of sonic transducers (1) radially disposed about an axis and angled to direct sonic energy (12) towards said axis at a point remote from said array, each transducer being adapted for angular movement relative to the other transducers thereby to allow adjustment of the shape of the acoustic focus. The array is computer controlled both with regard to acoustic focus and with regard to the energy imparted by each member of the array, said control being mediated by temperatures sensing means (40) adjacent a tumor. This ultrasound unit may be associated with a heat treatment tank (51, 31) including a flexible membrane (32, 52) which may overlie a tumor, thereby to locally raise the temperature and reduce the amount of ultrasonic power required to achieve a desired temperature. Suitable adjustment of the focused energy raises the temperature of the tumor cells above viability whereas the same temperature applied to healthy cells still allows viability by virtue of their relatively greater heat dissipation ability.

Claims

1. An ultrasound hyperthermia unit for treatment of tumors comprising:

(a) ultrasound transducer means comprising an angled array of ultrasonic transducers, each transducer being individually movable, the ultrasound transducer means being angled for directing sonic energy toward an ultrasound acoustic focus, and the ultrasound acoustic focus being movable to substantially all locations within a tumor to be treated by moving the transducers individually;

(b) drive means for moving the individually movable transducers;

(c) temperature sensing means for sensing temperature within the tumor and for providing a signal indicative of temperature at a plurality of locations within the tumor; and

(d) a control circuit for receiving the signal indicative of temperature and for controlling the ultrasound transducer means and drive means, the control circuit being operable in response to the signal indicative of temperature for;

(1) controlling the power output of sonic energy by the ultrasound transducer means toward the ultrasound acoustic focus; and

(2) controlling the drive means to treat such tumor by automatically moving the transducers individually, to move the ultrasound acoustic focus to substantially all locations throughout the tumor volume for localized heating of tumor tissues above viability by controlled application of sonic energy; and

(e) the ultrasound acoustic focus and the sonic energy output being jointly controlled to raise the temperature of substantially all portions of the tumor to above the temperature of viability, each portion being heated substantially only long enough to kill such portion, tumor portions having nonuniform physical characteristics and blood supply being differentially treated to avoid substantial overheating.

2. A unit as in claim 1, wherein the sonic energy from said ultrasound transducer means heats such tumor tissues without being sufficient to cause substantial cavitation thereof.

3. An ultrasound hyperthermia unit for treatment of tumors comprising:

(a) an ultrasound transducer comprising a concave array of elements, each element being individually movable, the elements of the ultrasound transducer being angled for directing sonic energy toward an ultrasound acoustic focus, and the ultrasound acoustic focus being movable to substantially all parts of a tumor to be treated by moving the elements individually;

(b) drive means for moving the individually movable elements;

(c) a temperature sensing array for sensing the temperature within the tumor and for providing a signal indicative of temperature at a plurality of locations within the tumor;

(d) a heat treatment tank for containing a heat exchange fluid, the tank comprising a flexible heat conductive member for overlying the tumor to be treated for applying heat from the heat exchange fluid to raise the temperature of the skin adjacent the tumor;

(e) means for changing the temperature of the heat exchange fluid; and

(f) a control circuit for receiving the signal indicative of temperature and for controlling the ultrasound transducer, the drive means and the temperature changing means, the control circuit being operable in response to the signal indicative of temperature for;

(i) controlling the drive means to position the ultrasound acoustic focus within the tumor and for

(ii) controlling the heat applied to the skin adjacent the tumor by controlling the temperature changing means to change the temperature of the heat exchange fluid, while controlling the ultrasound transducer to direct sonic energy toward the ultrasound acoustic focus within the tumor;

(g) the drive means being controlled to treat such tumor by automatically moving the ultrasonic acoustic focus to substantially all locations throughout the tumor volume for localized treatment of tumor tissues above the temperature of viability, the temperature of each such portion being raised to above viability substantially only long enough to kill such portion, tumor portions having non-uniform physical characteristics and blood supply being differentially treated to avoid substantial overheating, and the sonic energy coacting with the heat applied by the heat treatment tank to carry out such heating.

4. A unit as in claim 3, wherein the sonic energy from said ultrasound transducer means heats such tumor tissues without being sufficient to cause substantial cavitation thereof.

5. A method for the controlled treatment of tissue by ultrasound hyperthermia comprising:

positioning a plurality of temperature sensors to sense the temperature at a plurality of locations within the tissue, the sensors providing a temperature dependent output signal;

individually adjusting each of an array of transducer elements to focus ultrasound acoustic energy from the transducer elements on an ultrasound acoustic focus within the tissue;

processing the temperature dependent output signal to obtain temperature information; and

adjusting the power output of ultrasound acoustic energy by the transducer elements and individually adjusting each of the array of transducer elements in response to the temperature information to move the ultrasound acoustic focus to a plurality of locations within the tissue to achieve localized heating of the tissue at each such location to above its viability levels substantially only long enough to kill such tissue while not exceeding the viability levels of adjacent healthy tissue.

6. The method of claim 5 further comprising:

applying a flexible heating jacket to skin adjacent the tissue; and

passing heated fluid through the flexible heating jacket to bring the skin to a temperature of approximately 41°

-43°

C. during the application of the ultrasound acoustic energy to coact with such energy to carry out such heating.

7. A method as in claim 5, including heating such tissue without applying sufficient sonic energy to cause substantial cavitation thereof.