Electromagnetic imaging and therapeutic (EMIT) systems

• US 6,332,087 B1
• Filed: 10/19/1999
• Issued: 12/18/2001
• Est. Priority Date: 07/05/1996
• Status: Expired due to Term

• Current Assignee: EMTensor GmbH, The Carolinas Heart Institute
• Original Assignee: The Carolinas Heart Institute
• Inventors: Baranov, Vladimir, Svenson, Robert H., Semenov, Serguei Y.
• Primary Examiner(s): Casler, Brian L.
• Application Number:
  US09/420,660
• Time in Patent Office: 791 Days
• Field of Search: 600/407, 600/10, 600/2, 600/425, 600/430, 600/547, 607/89, 607/101, 324/637, 324/638, 324/639, 364/481, 364/482, 606/27, 606/32-34
• US Class Current: 600/407
• CPC Class Codes: A61B 18/1815 using microwaves
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/0507 using microwaves or terahertz waves
• CPC Class Codes: A61B 5/0536 Impedance imaging, e.g. by tomography

Abstract

The invention is a system and method for non-invasive tomographic spectroscopy of tissue using a plurality of microwave emitter-receivers spatially oriented to the tissue, an interface medium placed between the emitter-receivers, and a control subsystem operably coupled to the plurality of emitter-receivers for selectively controlling power to the plurality of emitter-receivers and for receiving signals from the plurality of emitter-receivers so that multiple frequency radiation is emitted from a selected plurality of emitter-receivers and received by a selected plurality of emitter-receivers after interacting with and passing through the tissue, and a computational subsystem operably connected to the control subsystem for computing a tomographic spectroscopic image of the tissue from the microwave signals received from the selected plurality of emitter-receivers.

Claims

1. A method of detecting the onset of biological tissue disease comprising the method of:

a) designating a target tissue area for electromagnetic irradiation;

b) determining expected tissue dielectric values for a designated target tissue area at frequencies above and below a relaxation frequency of the designated target tissue;

c) providing a multiple frequency radiation emitting and receiving system having emission means comprising a plurality of emitter-receiver locations, receiving means comprising a plurality of emitter-receiver locations, and signal analysis means;

d) irradiating the target tissue area with the multiple frequency radiation emitted from a plurality of emitter-receiver locations;

e) receiving the radiation from the irradiated target tissue area with microwave receiving means; and

f) analyzing the received radiation with the signal analysis means to obtain observed tissue dielectric values and comparing the observed tissue dielectric values for a desired range of frequencies best correlating to the target tissue with the expected tissue dielectric values to determine a change in the physiologic state of the target tissue indicative of an onset of tissue disease.

2. The method of claim 1 in which the multiple frequency radiation is preferably within a range of about 100 kHz to about 6 GHz.

3. A tomographic spectroscopic method of rapid non-invasive mapping of cardiac tissue to localize different physiologic states of the tissue, comprising the steps of:

a) designating a target cardiac tissue area for irradiation;

b) determining expected cardiac tissue dielectric values for the designated cardiac tissue area;

c) providing a multiple frequency radiation emitting and receiving system having radiation emission means comprising a plurality of emitter-receiver locations, radiation receiving means comprising a plurality of emitter-receiver locations, and radiation analysis means;

d) irradiating the target cardiac tissue area with the multiple frequency radiation emitted from a plurality of emitter-receiver locations;

e) receiving the radiation from the irradiated target cardiac tissue area with the radiation receiving means;

f) analyzing the received radiation with the radiation analysis means to obtain observed tissue dielectric values and comparing the observed tissue dielectric values with the expected tissue dielectric values to determine the physiologic states of the tissue within the designated target tissue area;

the analyzing and comparing step utilizing an E* calculation which functions as a representative value of dielectric contrast between tissue regions or tissue physiologic states, where E*=E

+iε

″ and

where E and

ε

″

are the values of measured dielectric permittivity and dielectric loss and i represents the imaginary number; and

g) displaying a representation of the irradiated target cardiac tissue area on a display means so that different physiologic states of the tissue are recognizable.

4. The method of claim 3 in which the analyzing and comparing step includes the step of solving the reverse problem to reconstruct tomographic biophysical images of the tissue based on the measured change of the radiation, the reverse problem solution step comprising the steps of:

a) determining a functional formation component;

b) calculating a derivative value of the functional formation component to create a gradient formation component useful for increasing the processing speed of the mathematical reconstruction calculations;

c) calculating a minimization parameter tau; and

d) performing an E* calculation.