Image obtaining apparatus

• US 6,800,057 B2
• Filed: 05/29/2002
• Issued: 10/05/2004
• Est. Priority Date: 05/29/2001
• Status: Expired due to Fees

• Current Assignee: Fujifilm Corporation (Fujifilm Holdings Corporation)
• Original Assignee: Fuji Photo Film Co Limited (Fujifilm Holdings Corporation)
• Inventors: Tsujita, Kazuhiro, Nakajima, Yukihiko
• Primary Examiner(s): Leubecker, John P.
• Application Number:
  US10/156,693
• Publication Number:
  US 20030013937A1
• Time in Patent Office: 860 Days
• Field of Search: 600/160, 600/178, 600/109, 600/181, 600/476, 600/478, 250/458.1, 250/461.2, 348/65, 348/74, 348/76
• US Class Current: 600/160
• CPC Class Codes: A61B 1/000094 extracting biological structures
• CPC Class Codes: A61B 1/00186 with imaging filters
• CPC Class Codes: A61B 1/043 for fluorescence imaging
• CPC Class Codes: A61B 1/0638 providing two or more wavelengths
• CPC Class Codes: A61B 1/0646 with illumination filters
• CPC Class Codes: A61B 5/0071 by measuring fluorescence emission
• CPC Class Codes: A61B 5/0084 for introduction into the body, e.g. by catheters A61B5/1459 takes precedence

Abstract

An accurate determination of the tissue state of a diseased portion is performed by use of an image obtaining apparatus employing a charge multiplying type solid state image obtaining element. A target subject is irradiated with an illuminating light that contains an excitation light, and the reflected light, which includes a fluorescence image, reflected from the target subject thereupon is detected by a charge multiplying type CCD. At this time, the fluorescent light image is passed through a rotating filter, and is detected as a wide band fluorescent light image and a narrow band fluorescent light image by the charge multiplying type CCD, and obtained as a wide band fluorescence image data and a narrow band fluorescence image data by an image processing unit. A fluorescence diagnostic image is obtained of the wide band fluorescence image data and the narrow band fluorescence image data, and displayed on a monitor.

Claims

1. An image obtaining apparatus comprising:

a light emitting means for projecting an illuminating light that includes an excitation light onto a target subject,

a charge multiplying type solid state image obtaining element for obtaining an optical image based on the re-radiated light, which contains fluorescent light, generated by the target subject upon the irradiation thereof by the illuminating light, and obtaining an output data representing the obtained optical image,

a filter means for extracting at least two different wavelength ranges from said fluorescent light so that said solid state image obtaining element can obtain fluorescence images based on fluorescent light of said different wavelength ranges, and

a correcting means for detecting dark noise generated by the solid state image obtaining element, and correcting the output data, based on the detected dark noise, to obtain a corrected output data, wherein

said correcting means is a means for correcting the output data representing the fluorescence images.

2. An image obtaining apparatus as defined in claim 1, wherein said correcting means is a means for performing the steps of:

causing the emission of the illuminating light from the light emitting means onto the target subject to be paused periodically at regular intervals,

detecting the dark noise based on the output signal obtained by the solid state image obtaining element during the interval in which the emission of said illuminating light has been paused, and

correcting, based on the detected dark noise, the output data obtained by the solid state image obtaining element during the interval in which the illuminating light has been projected onto the target subject to obtain a corrected output data.

3. An image obtaining apparatus as defined in claim 2, wherein

said filter means is a rotating filter means having at least two filter elements, each of which transmits a different wavelength range of light, wherein

by the rotation of the different filter elements, each of said filter elements can be made to positionally correspond with a light receiving surface of the solid state image obtaining element.

4. An image obtaining apparatus as defined in claim 2, wherein

said filter means is provided on a light receiving surface of the solid state image obtaining element, and formed of a combination of two or more types of filter elements, each of which transmits a different wavelength range of light, disposed alternately on a two-dimensional flat surface.

5. An image obtaining apparatus as defined in any of the claims 1 or 2, wherein

a portion or the entirety of the light emitting means and the solid state image obtaining element can be provided in the form of an endoscope for insertion into a body cavity of a patient.

6. An image obtaining apparatus as defined in either of claims 3 or 4, wherein

a portion or the entirety of the light emitting means and the solid state image obtaining element can be provided in the form of an endoscope for insertion into a body cavity of a patient.

7. An image obtaining apparatus as defined in claim 1, wherein

said filter means is a rotating filter means having at least two filter elements, each of which transmits a different wavelength range of light, wherein

by the rotation of the different filter elements, each of said filter elements can be made to positionally correspond with a light receiving surface of the solid state image obtaining element.

8. An image obtaining apparatus as defined in claim 7, wherein

a portion or the entirety of the light emitting means and the solid state image obtaining element can be provided in the form of an endoscope for insertion into a body cavity of a patient.

9. An image obtaining apparatus as defined in claim 1, wherein

said filter means is provided on a light receiving surface of the solid state image obtaining element, and formed of a combination of two or more types of filter elements, each of which transmits a different wavelength range of light, disposed alternately on a two-dimensional flat surface.

10. An image obtaining apparatus as defined in claim 9, wherein

a portion or the entirety of the light emitting means and the solid state image obtaining element can be provided in the form of an endoscope for insertion into a body cavity of a patient.

11. The apparatus of claim 1, wherein said filter means comprises a narrow band filter element and a wide band filter element providing outputs to the image obtaining element.

12. The apparatus of claim 11, wherein said light emitting means alternately emits the illuminating light of red, green, and blue wavelengths, an infrared wavelength, and an excitation wavelength, wherein the wide band filter element is disposed to provide outputs of red, green, blues, infrared and wide band fluorescence images to the image obtaining element and the narrow band filter element is disposed to provide output of a narrow band fluorescence image to the image obtaining element.

13. The apparatus of claim 12, wherein

said light emitting means comprises a light source and light source filter means for alternately extracting from light emitted by the light source said illuminating light of red, green, and blue wavelengths, and infrared wavelength, and wherein

said filter means and said light source filter means are formed as an integrated rotational filter.

14. The apparatus of claim 1 further comprising a blocking device to block the illuminating light, wherein dark noise is determined by reading an image when the blocking device is disposed to block the illuminating light.

15. The apparatus of claim 14, wherein a ratio of a wide band dark image to a narrow band dark image is used to correct for dark noise.