Invasive hyperthermia apparatus and method

• US 4,448,198 A
• Filed: 09/24/1981
• Issued: 05/15/1984
• Est. Priority Date: 06/19/1979
• Status: Expired due to Term

• Current Assignee: BSD Medical Corporation
• Original Assignee: BSD Medical Corporation
• Inventors: Turner, Paul F.
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US06/305,180
• Time in Patent Office: 964 Days
• Field of Search: 128/422, 128/804, 128/420 A
• US Class Current: 607/99
• CPC Class Codes: A61B 2018/0075 Phase
• CPC Class Codes: A61N 1/323 Interference currents, i.e. treatment by several currents summed in the body
• CPC Class Codes: A61N 5/02 using microwaves

Abstract

Invasive hyperthermia apparatus includes an electromagnetic energy radiation source, and a plurality of applicators. Each applicator is adapted for insertion into body tissue and radiating electromagnetic energy therein. Interconnected between the applicators and the radiation source are a power splitter and a plurality of line stretchers for providing the applicator with electromagnetic energy in a preselected frequency - phase power relationship. The applicators, power splitter and line stretchers are operative for causing constructive interference between emitted electromagnetic radiation when the applicators are inserted into body tissue in a preselected spaced apart relationship.

Claims

1. Electromagnetic hyperthermia apparatus for heating local regions within body tissue comprising:

(a) a source of electromagnetic radiation;

(b) a plurality of electromagnetic energy radiating applicators, wherein said applicators are inserted into the body tissue in a preselected pattern, and further wherein said applicators are substantially parallel; and

(c) means interconnected between the radiation source and each of said applicators for continuously providing each said applicator with electromagnetic energy having the same frequency and preselected relative phase and power relationships, wherein the radiation emitted by said applicators undergoes constructive interference in the local region to be heated.

2. The hyperthermia apparatus of claim 1, wherein said interconnected means comprises a power splitter, wherein the electromagnetic energy supplied to each of said applicators has the same relative phase and power.

3. The hyperthermia apparatus of claim 1, wherein said interconnected means comprises;

a power splitter coupled to said applicators and to said source; and

means coupled to said power splitter for controlling the relative phase of the electromagnetic energy applied to each of said applicators.

4. The hyperthermia apparatus of claim 3, wherein said controlling means comprises a plurality of line stretchers.

5. The hyperthermia apparatus of claim 3, wherein said controlling means comprises means for continuously varying the relative phase of the electromagnetic energy applied to said applicators.

6. The hyperthermia apparatus of claim 1, wherein said applicators are spaced so as to define the circumference of a circle.

7. The hyperthermia apparatus of claim 6, wherein the diameter of the cicle is no more than approximately three-quaters of a wavelength of the electromagnetic radiation in the tissue.

8. Electromagnetic hyperthermia apparatus for heating local regions within body tissue, comprising:

a source of electromagnetic radiation;

a plurality of individual electromagnetic energy radiators suitable for substantially parallel insertion into the body tissue so as to define points equally spaced on the circumference of a circle;

a power splitter coupled to said source; and

9. a plurality of line stretchers coupled between said power splitter and said applicators, wherein the relative phase of energy supplied to said applicators is controlled by said line stretchers.

11. The method of claim 9, wherein step (b) comprises the step of simultaneously providing all of the applicators with electromagnetic energy having the same frequenc, relative phase and power.

12. The method of claim 9 further comprising the step of:

(c) continuously varying the relative phase of the electromagnetic energy provided to the applicators.

10. A method for heating local regions within body tissue with electromagnetic radiation, comprising the steps of:

(a) inserting a plurality of electromagnetic energy radiating applicators into the body tissue in a substantially parallel, spaced apart relationship; and

(b) simultaneously providing all of the applicators with electromagnetic energy having aligned fields, the same frequency, and preselected relative phase and power relationships.