Method for mapping internal body tissue

• US 6,529,759 B1
• Filed: 03/08/2001
• Issued: 03/04/2003
• Est. Priority Date: 03/08/2001
• Status: Expired due to Term

• Current Assignee: Magstim Group, Incorporated
• Original Assignee: Electrical Geodesics, Inc. (Koninklijke Philips N.V.)
• Inventors: Tucker, Don, Tucker, Susan E.
• Primary Examiner(s): Hoang, Tu Ba
• Application Number:
  US09/803,085
• Time in Patent Office: 726 Days
• Field of Search: 600/407, 600/409, 600/410, 600/414, 600/418, 600/421, 600/425, 600/436, 600/544, 600/545, 600/547, 600/562, 600/372, 600/382, 600/384, 600/386, 600/461, 600/476, 600/477, 600/478, 250/272, 250/273, 250/274, 250/277.R, 250/278, 250/279, 378/62, 378/54, 378/19, 378/145, 378/146
• US Class Current: 600/407
• CPC Class Codes: A61B 2562/02 Details of sensors specially adapted for in-vivo measurements
• CPC Class Codes: A61B 2562/046 in a matrix array
• CPC Class Codes: A61B 5/0059 using light, e.g. diagnosis by transillumination, diascopy, fluorescence A61B5/0093, A61B5/1455, A61B5/02416 and A61B5/0261 take precedence
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/4509 Bone density determination
• CPC Class Codes: A61B 5/6814 Head
• CPC Class Codes: A61B 8/4272 involving the acoustic interface between the transducer and the tissue

Abstract

A method for mapping internal body tissue. The method preferably includes determining the spatial distribution of bone tissue of a patient that shields target soft tissue, the structure of which it is desired to determine and monitor, and subjecting the patient to changing electric, magnetic or electromagnetic fields adapted for interacting with the target soft tissue as a function of the spatial distribution of the soft tissue. Electric, magnetic or electromagnetic energy that is transmitted through the bone and the soft tissue is analyzed to infer the spatial distribution of the soft tissue with the assistance of knowledge of the spatial distribution of the bone tissue.

Claims

1. A method for mapping tissue of a body, the tissue being at least partially shielded by bone, comprising:

(a) determining the density of the bone as a function of spatial coordinates;

(b) applying a first input signal to the tissue through the surface of the body;

(c) measuring a first output signal representing said input signal as modified by the tissue;

(d) determining a relationship between said input signal and said output signal, said relationship being a function of the density of the bone as well as the density of the tissue; and

(e) employing the result of step (a) in step (d) to reduce the number of unknowns in said step (d).

2. The method of claim 1, wherein step (a) further comprises irradiating the bone with input X-rays, measuring a second output signal representing said input X-rays as modified by the bone, and determining a relationship between said input X-rays and said second output signal, said relationship being a function of the density of the bone.

3. The method of claim 2, wherein, in step (b), said input signal is a current directly applied to the skin.

4. The method of claim 2, wherein, in step (b), said input signal is an electromagnetic wave in the near-infrared.

5. The method of claim 3, further comprising (f) applying a second input signal to the tissue through the surface of the body, wherein step (d) further comprises determining a relationship between said second input signal and said output signal, said relationship being a function of the density of the bone as well as the density of the tissue.

6. The method of claim 5, wherein, in step (f), said second input signal is an electromagnetic wave in the near-infrared.

7. The method of claim 4, further comprising (f) applying a second input signal to the tissue through the surface of the body, wherein step (d) further comprises determining a relationship between said second input signal and said output signal, said relationship being a function of the density of the bone as well as the density of the tissue.

8. The method of claim 7, wherein, in step (f), said second input signal is a current directly applied to the skin.