Ultrasonic treatment of pathological tissue

• US 5,209,221 A
• Filed: 09/20/1991
• Issued: 05/11/1993
• Est. Priority Date: 03/01/1988
• Status: Expired due to Fees

• Current Assignee: Rainer E. Riedlinger
• Original Assignee: Richard Wolf GmbH (Richard & Annemarie Wolf- Stiftung)
• Inventors: Riedlinger, Rainer
• Primary Examiner(s): Cohen, Lee S.
• Assistant Examiner(s): PONTIUS, KEVIN LANE
• Application Number:
  US07/763,475
• Time in Patent Office: 599 Days
• Field of Search: 128/24 EL, 128/660.03, 128/24 AA, 606/127, 606/128, 310/317, 310/335
• US Class Current: 601/2
• CPC Class Codes: A61B 17/22004 using mechanical vibrations, e.g. ultrasonic shock waves A61B17/225 takes precedence
• CPC Class Codes: A61B 2017/0015 applied simultaneously
• CPC Class Codes: A61B 2017/00172 Pulse trains, bursts, intermittent continuous operation
• CPC Class Codes: A61B 2017/22008 used or promoted
• 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: G10K 11/28 using reflection, e.g. parabolic reflectors

Abstract

A device for generating sonic signal forms for limiting, preventing or regressing the growth of pathological tissue comprises an ultrasonic transmission system for transmitting sound waves, focussed on the tissue to be treated, by way of a coupling medium. An ultrasonic signal produced at the focus of the system comprises brief pulses having at least one rarefaction phase with a negative sonic pressure amplitude with a value greater than 2×10⁵ Pa. The ultrasonic signal is radiated with a carrier frequency exceeding 20 kHz, a sonic pulse duration T of less than 100 μs and a pulse recurrence rate of less than 1/(5T). The device produces controlled cavitation in the tissue to be treated.

Claims

1. An ultrasonic transmission system for the treatment of pathological tissue by producing controlled cavitation in the pathological tissue comprising:

an ultrasonic pulse generating means comprising;

means for generating an ultrasonic signal having a carrier frequency exceeding 20 kHz;

means for generating pulses for controlled pathological tissue cavitation, said pulse generating means coupled to said signal generating means to generate briefly emitted pulses of said ultrasonic signal, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa in value, a pulse duration (T) of less than 100 μ

s, and a pulse recurrence rate of less than 1/(5T); and

means for focussing said ultrasonic pulses, said focussing means positioned with respect to said ultrasonic pulse generating means to focus the ultrasonic pulses generated therefrom upon a focal point whereby location of pathological tissue at the focal point of said focussing means and generation of ultrasonic pulses by way of a coupling medium by said ultrasonic pulse generating means upon the pathological tissue so located effects the destruction thereof by controlled cavitation,

said pulse generating means being capable of producing at said focal point a pulse envelope amplitude profile which is shaped as an exponential function.

2. An ultrasonic transmission system for the treatment of pathological tissue by producing controlled cavitation in the pathological tissue comprising:

an ultrasonic pulse generating means comprising;

means for generating an ultrasonic signal having a carrier frequency exceeding 20 kHz;

means for generating pulses for controlled pathological tissue cavitation, said pulse generating means coupled to said signal generating means to generate briefly emitted pulses of said ultrasonic signal, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa in value, a pulse duration (T) of less than 100 μ

s, and a pulse recurrence rate of less than 1/(5T); and

means for focussing said ultrasonic pulses, said focussing means positioned with respect to said ultrasonic pulse generating means to focus the ultrasonic pulses generated therefrom upon a focal point whereby location of pathological tissue at the focal point of said focussing means and generation of ultrasonic pulses by way of a coupling medium by said ultrasonic pulse generating means upon the pathological tissue so located effects the destruction thereof by controlled cavitation,

said pulse generating means being capable of producing at said focal point a pulse envelope amplitude profile which is shaped as a Gaussian function.

3. An ultrasonic transmission system for the treatment of pathological tissue by producing controlled cavitation in the pathological tissue comprising:

an ultrasonic pulse generating means comprising;

means for generating an ultrasonic signal having a carrier frequency exceeding 20 kHz;

means for generating pulses for controlled pathological tissue cavitation, said pulse generating means coupled to said signal generating means to generate briefly emitted pulses of said ultrasonic signal, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa in value, a pulse duration (T) of less than 100 μ

s, and a pulse recurrence rate of less than 1/(5T); and

means for focussing said ultrasonic pulses, said focussing means positioned with respect to said ultrasonic pulse generating means to focus the ultrasonic pulses generated therefrom upon a focal point whereby location of pathological tissue at the focal point of said focussing means and generation of ultrasonic pulses by way of a coupling medium by said ultrasonic pulse generating means upon the pathological tissue so located effects the destruction thereof by controlled cavitation,

said pulse generating means being capable of producing at said focal point a pulse envelope amplitude profile which is a stepped profile.

4. An ultrasonic transmission system for the treatment of pathological tissue by producing controlled cavitation in the pathological tissue comprising:

an ultrasonic pulse generating means comprising;

means for generating an ultrasonic signal having a carrier frequency exceeding 20 kHz;

means for generating pulses for controlled pathological tissue cavitation, said pulse generating means coupled to said signal generating means to generate briefly emitted pulses of said ultrasonic signal, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa in value, a pulse duration (T) of less than 100 μ

s, and a pulse recurrence rate of less than 1/(5T); and

means for focussing said ultrasonic pulses, said focussing means positioned with respect to said ultrasonic pulse generating means to focus the ultrosonic pulses generated therefrom upon a focal point whereby location of pathological tissue at the focal point of said focussing means and generation of ultrasonic pulses by way of a coupling medium by said ultrasonic pulse generating means upon the pathological tissue so located effects the destruction thereof by controlled cavitation,

said pulse generating means being capable of producing at said focal point a pulse envelope amplitude profile which is shaped as a sloping linear function.

5. An ultrasonic transmission system for the treatment of pathological tissue by producing controlled cavitation in the pathological tissue comprising:

an ultrasonic pulse generating means comprising;

means for generating an ultrasonic signal having a carrier frequency exceeding 20 kHz;

means for generating pulses for controlled pathological tissue cavitation, said pulse generating means coupled to said signal generating means to generate briefly emitted pulses of said ultrasonic signal, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa in value, a pulse duration (T) of less than 100 μ

s, and a pulse recurrence rate of less than 1/(5T); and

means for focussing said ultrasonic pulses, said focussing means positioned with respect to said ultrasonic pulse generating means to focus the ultrasonic pulses generated therefrom upon a focal point whereby location of pathological tissue at the focal point of said focussing means and generation of ultrasonic pulses by way of a coupling medium by said ultrasonic pulse generating means upon the pathological tissue so located effects the destruction thereof by controlled cavitation,

said pulse generating means being capable of producing at said focal point a pulse envelope amplitude profile which is a rectangular profile.

6. The ultrasonic transmission system as claimed in claim 5, wherein said pulse generating means is further characterized as capable of producing initially a rarefaction phase.

7. The ultrasonic transmission system as claimed in claim 6, wherein said ultrasonic signal generating means is further characterized as capable of producing a signal having a carrier frequency between 0.2 and 4 MHz, whereby the duration of each said rarefaction phase can be less than 2.5 μ

s.

8. The ultrasonic transmission system as claimed in claim 5, wherein said pulse generating means is further characterized as capable of producing pulses the duration of which measured at the focal point of said focussing means is equal to the cycle length of the carrier frequency and is synchronized with its passages through zero.

9. The ultrasonic transmission system as claimed in claim 5, wherein said ultrasonic signal generating means is further characterized as capable of producing a signal having a carrier frequency between 0.2 and 4 MHz, whereby the duration of each said rarefaction phase can be less than 2.5 μ

s.

10. An ultrasonic transmission system for the treatment of pathological tissue by producing controlled cavitation in the pathological tissue comprising:

an ultrasonic pulse generating means comprising;

means for generating an ultrasonic signal having a carrier frequency exceeding 20 kHz;

means for generating pulses for controlled pathological tissue cavitation, said pulse generating means coupled to said signal generating means to generate briefly emitted pulses of said ultrasonic signal, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa in value, a pulse duration (T) of less than 100 μ

s, and a pulse recurrence rate of less than 1/(5T); and

means for focussing said ultrasonic pulses, said focussing means positioned with respect to said ultrasonic pulse generating means to focus the ultrasonic pulses generated therefrom upon a focal point whereby location of pathological tissue at the focal point of said focussing means and generation of ultrasonic pulses by way of a coupling medium by said ultrasonic pulse generating means upon the pathological tissue so located effects the destruction thereof by controlled cavitation,

said pulse generating means producing at said focal point a pulse envelope amplitude profile which is adapted to the treatment that is needed, and

said focussing means further comprising first and second focussing reflectors one of which reflects in a soft manner and the other of which reflects in a hard manner, said reflectors being so staggered spatially with respect to said signal generating means and said pulse generating means so that said signal is a signal of alternative prefix and is produced in a common focal area of the first reflector and of a combination of the second reflector with the first reflector.

11. The ultrasonic transmission system as claimed in claim 10, wherein said pulse generating means is further characterized as capable of producing initially a rarefaction phase.

12. The ultrasonic transmission system as claimed in claim 10, wherein said pulse generating means is further characterized as capable of producing initially a positive pressure phase.

13. An ultrasonic transmission system for the treatment of pathological tissue by producing controlled cavitation in the pathological tissue comprising:

an ultrasonic pulse generating means comprising;

means for generating an ultrasonic signal having a carrier frequency exceeding 20 kHz;

means for generating pulses for controlled pathological tissue cavitation, said pulse generating means coupled to said signal generating means to generate briefly emitted pulses of said ultrasonic signal, each pulse having at least one rarfaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa in value, a pulse duration (T) of less than 100 μ

s, and a pulse recurrence rate of less than 1/(5T); and

means for focussing said ultrasonic pulses, said focussing means positioned with respect to said ultrasonic pulse generating means to focus the ultrasonic pulses generated therefrom upon a focal point whereby location of pathological tissue at the focal point of said focussing means and generation of ultrasonic pulses by way of a coupling medium by said ultrasonic pulse generating means upon the pathological tissue so located effects the destruction thereof by controlled cavitation,

said pulse generating means producing at said focal point a pulse envelope amplitude profile which is adapted to the treatment that is needed, and

said focussing means further comprising two mutually confronting focussing reflectors, one of which reflects in a soft manner and the other of which reflects in a hard manner, said reflectors spatially positioned and offset with respect to said ultrasonic signal producing means and said pulse generating means so that said signal is a signal of alternative prefix and is produced in the common focal area of said reflectors.

14. The ultrasonic transmission system as claimed in claim 13, wherein said pulse generating means is further characterized as capable of producing initially a rarefaction phase.

15. The ultrasonic transmission system as claimed in claim 13, wherein said pulse generating means is further characterized as capable of producing initially a positive pressure phase.

16. A method of treating pathological tissue using an ultrasonic signal comprising the steps of:

providing an ultrasonic transmission system capable of producing an ultrasonic signal at a focus of the system;

locating tissue to be treated;

producing controlled cavitation in the tissue to be treated by operating the system to emit an ultrasonic signal formed of pulses focussed on the tissue to be treated, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa, the signal having a carrier frequency greater than 20 kHz, a pulse duration (T) less than 100 μ

s, and a pulse recurrence rate less than 1/(5T), and each pulse having at said focus a pulse envelope amplitude profile which is adapted to the treatment that is needed, said profile having the shape of an exponential function.

17. A method of treating pathological tissue using an ultrasonic signal comprising the steps of:

providing an ultrasonic transmission system capable of producing an ultrasonic signal at a focus of the system;

locating tissue to be treated;

producing controlled cavitation in the tissue to be treated by operating the system to emit an ultrasonic signal formed of pulses focussed on the tissue to be treated, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa, the signal having a carrier frequency greater than 20 kHz, a pulse duration (T) less than 100 μ

s, and a pulse recurrence rate less than 1/(5T), and each pulse having at said focus a pulse envelope amplitude profile which is adapted to the treatment that is needed, said profile having the shape of a Gaussian function.

18. A method of treating pathological tissue using an ultrasonic signal comprising the steps of:

providing an ultrasonic transmission system capable of producing an ultrasonic signal at a focus of the system;

locating tissue to be treated;

producing controlled cavitation in the tissue to be treated by operating the system to emit an ultrasonic signal formed of pulses focussed on the tissue to be treated, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa, the signal having a carrier frequency greater than 20 kHz, a pulse duration (T) less than 100 μ

s, and a pulse recurrence rate less than 1/(5T), and each pulse having at said focus a pulse envelope amplitude profile which is adapted to the treatment that is needed, said profile being a stepped profile.

19. A method of treating pathological tissue using an ultrasonic signal comprising the steps of:

providing an ultrasonic transmission system capable of producing an ultrasonic signal at a focus of the system;

locating tissue to be treated;

producing controlled cavitation in the tissue to be treated by operating the system to emit an ultrasonic signal formed of pulses focussed on the tissue to be treated, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa, the signal having a carrier frequency greater than 20 kHz, a pulse duration (T) less than 100 μ

s, and a pulse recurrence rate less than 1/(5T), and each pulse having at said focus a pulse envelope amplitude profile which is adapted to the treatment that is needed, said profile having the shape of a sloping linear function.

20. A method of treating pathological tissue using an ultrasonic signal comprising the steps of:

providing an ultrasonic transmission system capable of producing an ultrasonic signal at a focus of the system;

locating tissue to be treated;

producing controlled cavitation in the tissue to be treated by operating the system to emit an ultrasonic signal formed of pulses focussed on the tissue to be treated, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa, the signal having a carrier frequency greater than 20 kHz, a pulse duration (T) less than 100 μ

s, and a pulse recurrence rate less than 1/(5T), and each pulse having at said focus a pulse envelope amplitude profile which is adapted to the treatment that is needed, said profile being a rectangular envelope profile.

21. The method of claim 20, wherein a pulse begins with said rarefaction phase.

22. The method of claim 21, wherein the carrier frequency lies between 0.2 and 4 MHz, the duration of each said rarefaction phase being less than 2.5 μ

s.

23. The method of claim 20, wherein the duration of pulse measured at said focus is equal to the period of the carrier frequency and the beginning of the pulse is synchronized with the passage through zero of the carrier frequency.

24. The method of claim 20, wherein the carrier frequency lies between 0.2 and 4 MHz, the duration of each said rarefaction phase being less than 2.5 μ

s.

25. A method of treating pathological tissue using an ultrasonic signal comprising the steps of:

providing an ultrasonic transmission system capable of producing an ultrasonic signal at a focus of the system;

locating tissue to be treated;

producing controlled cavitation in the tissue to be treated by operating the system to emit an ultrasonic signal formed of pulses focussed on the tissue to be treated, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa, the signal having a carrier frequency greater than 20 kHz, a pulse duration (T) less than 100 μ

s, and a pulse recurrence rate less than 1/(5T), and each pulse having at said focus a pulse envelope amplitude profile which is adapted to the treatment that is needed;

said step is emitting an ultrasonic signal comprising the step of generating said signal using the steam bubble explosion principle; and

said step of producing controlled cavitation comprising the steps of reflecting the signal both off a first focussing reflector in a soft manner and off a second focussing reflector in a hard manner, said reflections occurring so as to produce a signal of alternative prefix and to produce controlled cavitation in a common focal area of the first reflector and of a twin reflector formed by the combination of the first and second reflectors.

26. The method of claim 25, wherein a pulse begins with said rarefaction phase.

27. The method of claim 25, wherein a pulse begins with a positive pressure phase.

28. A method of treating pathological tissue using an ultrasonic signal comprising the steps of:

providing an ultrasonic transmission system capable of producing an ultrasonic signal at a focus of the system;

locating tissue to be treated;

producing controlled cavitation in the tissue to be treated by operating the system to emit an ultrasonic signal formed of pulses focussed on the tissue to be treated, each pulse having at least one rarefaction phase of negative sonic pressure amplitude exceeding 2×

10⁵ Pa, the signal having a carrier frequency greater than 20 kHz, a pulse duration (T) less than 100 μ

s, and a pulse recurrence rate less than 1/(5T), and each pulse having at said focus a pulse envelope amplitude profile which is adapted to the treatment that is needed;

said step of emitting an ultrasonic signal comprising the step of generating said signal using the steam bubble explosion principle; and

said step of producing controlled cavitation comprising the steps of reflecting the signal both off first and second mutually confronting focussing reflectors, reflection off the first focussing reflector occurring in a soft manner, reflection off the second focussing reflector occurring in a hard manner, said reflections occurring so as to produce a signal of alternative prefix and to produce controlled cavitation in a common focal area of said reflectors.

29. The method of claim 28, wherein a pulse begins with said rarefaction phase.

30. The method of claim 28, wherein a pulse begins with a positive pressure phase.