Method for investigation of distribution of physiological components in human body tissues and apparatus for its realization

• US 5,747,789 A
• Filed: 07/11/1996
• Issued: 05/05/1998
• Est. Priority Date: 12/01/1993
• Status: Expired due to Fees

• Current Assignee: DOBI Medical Systems, Inc. (IBOD Imaging, Inc.)
• Original Assignee: Dynamic Imaging Incorporated (General Electric Company)
• Inventors: Godik, Eduard E.
• Primary Examiner(s): Westin, Edward P.
• Assistant Examiner(s): Lee, John R.
• Application Number:
  US08/678,786
• Time in Patent Office: 663 Days
• Field of Search: 250/226, 250/208.1, 250/562, 250/330, 250/339.02, 250/363.02, 250/363.09, 250/341.8, 250/341.5, 250/341.1, 128/691, 128/664, 128/665, 128/654, 128/633, 128/653.1, 364/413.13
• US Class Current: 250/208.1
• 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

Abstract

The method of investigation of physiological components distribution in human body tissues includes optical illumination of the investigated area, recording of the spatial distribution of the intensity of the light reflected by the investigated area within a definite period of time through sequential time intervals, which are small compared to the time constant of the investigated process. The wavelength of the illuminating or recorded reflected radiation is chosen at one of the spectral intervals with a maximal steepness of the spectral changes in the physiological pigments absorption, this radiation being modulated by the frequency and the amplitude-modulated part of the reflected light thus appearing is recorded synchronously at the modulation frequency. In one aspect of the method, the investigated area is illuminated at one or several points and the reflected radiation is recorded at points shifted relative to the illuminated ones. An apparatus for investigation of distribution of physiological components in human body tissues contains an illuminator for the optical illumination of the investigated area with a control block, a detecting device for recording of the investigated area images, means for assignment of the radiation wavelength, a system of image formation, a video control device, a dynamic interface board for formation and accumulation at the video memory of the image processing system of the frame sequence.

Claims

1. An apparatus for the investigation of distribution of physiological components in human body tissues over a preselected area of the body comprising:

illumination means for providing electromagnetic radiation to illuminate the preselected area of the body at one or more spectral bands;

control means operably connected to said illumination means for modulating said illumination means in both frequency and amplitude;

photodetector means for receiving and recording spatial distribution of intensity of electromagnetic radiation reflected from said preselected area of the body;

accumulator means operably connected to said control means and said photodetector means for;

forming sequences of video images over a preselected period of time from said recorded spatial distribution of intensity of said reflected electromagnetic radiation from said preselected area of the body;

subtracting a reference video image from any video image from said sequences of video images resulting in sequences of subtracted video images; and

accumulating said sequences of subtracted video images for processing in a computer;

display means operably connected to said computer for displaying, based upon said sequences of subtracted video images, the distribution of physiological components in human body tissues over the preselected area of the body; and

interface means for coordinating said control means with said photodetector means and said accumulator means by said computer.

2. The apparatus as defined in claim 1 wherein illumination means comprises a source of electromagnetic radiation and means for diffusing said electromagnetic radiation to provide uniform illumination to said preselected area of the body.

3. The apparatus as defined in claim 1 wherein the spectral band of said electromagnetic radiation is less than the frequency interval over which the frequency modulation is performed.

4. The apparatus as defined in claim 1 wherein said illuminator means comprises an array of electromagnetic radiation sources to provide nonuniform illumination to said preselected area of the body in order to provide points of illumination of said preselected area of the body.

5. The apparatus as defined in claim 4 further comprising optical means for varying the size, form and position of projection of said array of electromagnetic radiation sources onto said preselected area of the body.

6. The apparatus as defined in claim 4 further comprising:

another photodetector, in addition to said photodetector means, said other photodetector comprising an array of photodetectors arranged in a similar fashion to said array of electromagnetic radiation sources;

optical means interposed between said array of sources and said other photodetector for projecting an optical image of said array of sources on said preselected area of the body and focusing electromagnetic radiation from said optical image reflected from the preselected area of the body onto said other photodetector; and

synchronous detector means operably connected to said other photodetector for synchronous recording of frequency and amplitude modulated electromagnetic radiation reflected at points shifted from said points of illumination of said preselected area of the body and for providing an output therefrom.

7. The apparatus as defined in claim 6 wherein said array of electromagnetic radiation sources and said array of photodetectors are combined into a single device wherein said sources and said photodetectors are arranged in alternating rows and columns.

8. The apparatus as defined in claim 6 wherein said array of electromagnetic radiation sources and said array of photodetectors are combined into a single device by arranging said sources and said photodetectors in alternating rows.

9. A method for investigation of distribution of physiological components in human body tissues comprising the steps of:

illuminating a preselected area of the human body to be investigated with electromagnetic radiation at one or more spectral bands;

recording spatial distribution of the intensity of reflected electromagnetic radiation from the preselected area of the human body continuously over a predetermined period of time;

forming sequences of video images from said recorded spatial distributions over said predetermined period of time;

subtracting a reference video image from any video image from said sequences of video images resulting in sequences of subtracted video images;

accumulating said sequences of subtracted video images for processing in a computer; and

viewing, based upon said sequences of subtracted video images, the distribution of physiological components in human body tissues over the preselected area of the body.

10. The method as defined in claim 9 wherein said electromagnetic radiation provides uniform illumination to the preselected area of the body.

11. The method as defined in claim 9 further comprising the step of illuminating the area of the human body with an array of sources for nonuniform illumination of the points on the human body in patterns which vary in size, form and location.

12. The method as defined in claim 11 further comprising the step of using an array of photodetectors to record reflected radiation at points displaced from said points illuminated by said array of sources.