RF power controller for ultrasound therapy system

• US 9,931,523 B2
• Filed: 03/09/2011
• Issued: 04/03/2018
• Est. Priority Date: 03/09/2010
• Status: Active Grant

• Current Assignee: Profound Medical Inc. (Profound Medical Corp.)
• Original Assignee: Profound Medical Inc. (Profound Medical Corp.)
• Inventors: Mahon, Cameron, Yak, Nicolas, Chopra, Rajiv, Asselin, Mathew, Bronskill, Michael
• Primary Examiner(s): Moher, Amanda Lauritzen
• Assistant Examiner(s): Mohammed, Shahdeep
• Application Number:
  US12/932,923
• Publication Number:
  US 20110270366A1
• Time in Patent Office: 2,582 Days
• Field of Search: None
• CPC Class Codes: A61B 17/225 for extracorporeal shock wave lithotripsy [ESWL], e.g. by using ultrasonic waves
• CPC Class Codes: A61N 2007/0095 by modifying an excitation signal
• CPC Class Codes: A61N 7/00 Ultrasound therapy lithotripsy A61B17/22, A61B17/225; massage using supersonic vibration A61H23/00 ; using ultrasound for introducing media into the body A61M37/0092
• CPC Class Codes: A61N 7/022 intracavitary

Abstract

An apparatus for driving and controlling ultrasonic elements includes a computer-based host unit that determines driving characteristics with which to drive the ultrasonic elements; a microprocessor-based controller that receives an output from the host and provides signals representing a frequency and/or an amplitude characteristic; a frequency control circuit receiving the frequency characteristic signal; an amplitude control circuit receiving the amplitude characteristic signal; an RF amplifier acting on an output from the frequency and/or the amplitude control circuits to provide an amplified output signal corresponding to the frequency and/or amplitude characteristic; a coupling circuit that couples the amplified output signal to the ultrasonic elements and provides a forward output signal to a first RF detector circuit and a reverse output signal to a second RF detector circuit; and an analog-to-digital converter that receives an output of the RF detector circuits and provides a corresponding converted output to the controller.

Claims

1. An apparatus for driving and controlling a plurality of ultrasonic elements in an array in a system for thermal therapy of diseased tissue operating through the application of the plurality of ultrasonic elements in the array, the apparatus comprising:

a computer-based host unit that determines a desired set of driving characteristics with which to drive said plurality of ultrasonic elements;

a microprocessor-based controller that receives an output from said host and provides at least signals representing a frequency characteristic and an amplitude characteristic;

a frequency control circuit in electrical communication with said controller, said frequency control circuit configured to receive said frequency characteristic signal from said controller and to provide a first output signal;

an amplitude control circuit in electrical communication with said controller, said amplitude control circuit configured to receive said amplitude characteristic signal from said controller and to provide a second output signal;

a radio frequency (RF) amplifier in electrical communication with said frequency and said amplitude control circuits, said RF amplifier configured to act on said first output signal and said second output signal and to provide an amplified output signal having both frequency and amplitude characteristics corresponding to said frequency characteristic and said amplitude characteristic;

a coupling circuit in electrical communication with said RF amplifier and said plurality of ultrasonic elements, said coupling circuit configured to receive said amplified output signal and to couple the same to a corresponding plurality of said ultrasonic elements in said array;

a first RF detector circuit in electrical communication with said coupling circuit, said first RF detector circuit configured to sense a forward RF power delivered to each of said ultrasonic elements;

a second RF detector circuit in electrical communication with said coupling circuit, said second RF detector circuit configured to sense a reverse RF power from each of said ultrasonic elements;

and

an analog-to-digital converter that receives outputs of said first and second RF detector circuits and provides a corresponding converted output to said microprocessor-based controller, said converted output corresponding to said forward RF power and said reverse RF power sensed by said first and second RF detector circuits;

wherein the microprocessor-based controller tunes at least one of said frequency characteristic and said amplitude characteristic according to said forward RF power and said reverse RF power.

2. The apparatus of claim 1, said frequency control circuit further providing an output to said amplitude control circuit.

3. The apparatus of claim 1, said converted output comprising a digital output suitable for use by said microprocessor-based controller.

4. The apparatus of claim 1 said microprocessor-based controller comprising a proportional integral derivative controller.

5. The apparatus of claim 1 said microprocessor-based controller comprising an application-specific integrated circuit.

6. A method for ultrasound thermal therapy in a patient, comprising:

determining a desired therapeutic result of said therapy;

inserting a thermal therapy apparatus into an orifice in said patient;

positioning said thermal therapy apparatus in said patient so that an ultrasonic array of transducer elements is at least partially located within a volume of diseased tissue of said patient;

in a computer-based host unit, determining a driving frequency and amplitude or power level with which to drive each of the transducer elements of said array to achieve said desired therapeutic result;

providing host output signals from said host unit to a microprocessor-based controller, said host output signals representing said driving frequency and said amplitude or said power level;

in a frequency control circuit, receiving said host output signal representing said driving frequency, said frequency control circuit further providing a first output signal;

in an amplitude control circuit, receiving said host output signal representing said amplitude or said power level, said amplitude control circuit further providing a second output signal;

providing said first output signal and said second output signal to a radio frequency (RF) amplifier in electrical communication with said frequency control circuit and said amplitude control circuit, said RF amplifier acting on said first output signal and said second output signal to provide an amplified output signal having both frequency and amplitude characteristics corresponding to said frequency characteristic and said amplitude characteristic;

providing said amplified output signal to a corresponding plurality of said ultrasonic elements in said array;

in a first RF detector circuit, sensing a forward RF power delivered to each of said elements of said array;

in a second RF detector circuit, sensing a reverse RF power from each of said elements of said array;

providing said forward and said reverse RF power as inputs to said controller; and

generating in said controller, using said inputs, control output signals to control at least said frequency with which to drive said elements of said array.

7. The method of claim 6, further comprising making temperature measurements in said diseased tissue and adjusting at least said amplitude with which to drive said elements of said array.

8. The method of claim 6 further comprising averaging said forward driving signals.

9. The method of claim 6 further comprising averaging said reverse signals.

10. The method of claim 6 further comprising generating said control output signals based at least in part on an expected output power to said array.

11. The method of claim 6 further comprising generating said control output signals based at least in part on an existing output power of said array.

12. The method of claim 6 further comprising generating said control output signals based at least in part on said forward driving signals and said reverse signals.

13. The method of claim 6 further comprising generating in said microprocessor output signals to control at least said amplitude with which to drive said elements of said array.

14. The method of claim 13 further comprising generating said output signals with a proportional integral derivative controller.