Tissue imaging system and in vivo monitoring method

Patent metadata

Field	Value
Publication number	US-8965474-B2
Application number	US-201213464393-A
Country	US
Kind code	B2
Filing date	May 4, 2012
Priority date	May 12, 2011
Publication date	Feb 24, 2015
Grant date	Feb 24, 2015

Abstract

An in vivo monitoring method in a laparoscope system is provided. An object image is sequentially created with expression of a surface color of an object in a body cavity. A lock area (specific area) is determined within the object image, the lock area being movable by following motion of the object. A monitor image including a graph of oxygen saturation is generated according to a part image included in the object image and located in the lock area. The monitor image is displayed. Preferably, the oxygen saturation of the lock area is acquired according to two spectral data with respect to wavelengths of which an absorption coefficient is different between oxidized hemoglobin and reduced hemoglobin in data of the object image. The object is constituted by a blood vessel.

First claim

What is claimed is:

1. A tissue imaging system comprising:
an imaging unit configured to create an object image with information of oxygen saturation of a blood vessel;
an area determining unit configured to determine a lock area within said object image;
a location updating unit configured to update a location of said lock area according to motion of said object at each time of creating a frame of said object image, said location updating unit executing:
a landmark point extracting process to extract first landmark points from a first frame, and to extract second landmark points from a second frame created after creation of said first image, wherein said first and second landmark points are distinct from said lock area;
a landmark point specifying process to specify part of said second landmark points whose feature value is equal to part of said first landmark points;
a movement amount obtaining process to obtain a movement amount between said first and second landmark points whose feature value is equal; and
a location changing process to change the location of said lock area according to said movement amount;

a data acquisition unit configured to acquire said oxygen saturation in said lock area when said lock area is updated;
a monitor image generating unit configured to generate a monitor image including acquired change information of said oxygen saturation; and
a display unit configured to display said monitor image.

2. A tissue imaging system as defined in claim 1 , wherein said first and second landmark points are extracted from a form of said blood vessel in said object.

3. A tissue imaging system as defined in claim 2 , wherein said first and second landmark points are obtained by edge detection.

4. A tissue imaging system as defined in claim 1 , wherein said object image created by said imaging unit is two spectral images of wavelength components of light of which an absorption coefficient is different between oxidized hemoglobin and reduced hemoglobin, and said data acquisition unit acquires said oxygen saturation of said lock area according to said two spectral images.

5. A tissue imaging system as defined in claim 1 , wherein said monitor image generating unit generates a graph of said oxygen saturation changeable with time, and said monitor image includes said graph, and wherein said display unit displays a currently created frame of said object image within said monitor image together with said graph.

6. A tissue imaging system as defined in claim 1 , further comprising an alarm device for generating an alarm signal if said oxygen saturation in said lock area becomes equal to or lower than a predetermined level.

7. A tissue imaging system as defined in claim 1 , further comprising an illumination apparatus configured to apply narrow band light of a predetermined wavelength range and broad band light of a broad wavelength range alternately to said object;
wherein said imaging unit is a color image sensor for imaging said object illuminated with said narrow band light and said broad band light.

8. A tissue imaging system as defined in claim 7 , wherein said narrow band light has a wavelength range of 460-480 nm, and wherein said imaging unit obtains a special light mode image upon application of said narrow band light, and obtains a normal image upon application of said broad band light, as said object image.

9. A tissue imaging system as defined in claim 8 , wherein said data acquisition unit including:
a ratio generator configured to determine a first signal ratio of a blue signal of said special light mode image to a green signal of said normal image, and a second signal ratio of a red signal of said normal image to a green signal of said normal image;
a correlation memory configured to store information of a correlation between said oxygen saturation and said first and second signal ratios; and
an arithmetic processor configured to determine said oxygen saturation in said lock area by use of said correlation read from said correlation memory and said first and second signal ratios obtained by said ratio generator.

10. A tissue imaging system as defined in claim 1 , further comprising an illumination apparatus configured to apply plural narrow band light components of wavelength ranges different from one another to said object successively one after another;
wherein said imaging unit is a monochromatic image sensor for imaging said object illuminated with said narrow band light components.

11. A tissue imaging system as defined in claim 10 , wherein said plural narrow band light components are a first light component in a wavelength range of 460-480 nm, a second light component in a wavelength range of 540-580 nm, and a third light component in a wavelength range of 590-700 nm, and wherein said imaging unit obtains a blue signal corresponding to said first light component, a green signal corresponding to said second light component, and a red signal corresponding to said third light component, as said object image.

12. A tissue imaging system as defined in claim 11 , wherein said data acquisition unit including:
a ratio generator configured to determine a first signal ratio of said blue signal to said green signal, and a second signal ratio of said red signal to said green signal;
a correlation memory configured to store information of a correlation between said oxygen saturation and said first and second signal ratios; and
an arithmetic processor configured to determine said oxygen saturation in said lock area by use of said correlation read from said correlation memory and said first and second signal ratios obtained by said ratio generator.

13. A tissue imaging system as defined in claim 1 , wherein said object is present in an abdominal cavity, and said imaging unit is a laparoscope.

14. A tissue imaging system as defined in claim 1 , wherein said object is present in a gastrointestinal tract, and said imaging unit is an endoscope.

15. An in vivo monitoring method comprising steps of:
creating an object image with information of oxygen saturation of a blood vessel;
determining a lock area within said object image;
updating a location of said lock area according to motion of said object at each time of creating a frame of said object image, said updating step executing:
extracting first landmark points from a first frame, and to extract second landmark points from a second frame created after creation of said first image, wherein said first and second landmark points are distinct from said lock area;
specifying part of said second landmark points whose feature value is equal to part of said first landmark points;
obtaining a movement amount between said first and second landmark points whose feature value is equal; and
changing the location of said lock area according to said movement amount;

acquiring said oxygen saturation in said lock area when said lock area is updated;
generating a monitor image including acquired change information of said oxygen saturation; and
displaying said monitor image.

16. An in vivo monitoring method as defined in claim 15 , wherein said object image created by said creating step is two spectral images of wavelength components of light of which an absorption coefficient is different between oxidized hemoglobin and reduced hemoglobin, and in said acquiring step, said oxygen saturation of said lock area is acquired according to said two spectral images.

Assignees

• Yamaguchi Hiroshi
• Fujifilm Corp

Inventors

• Yamaguchi Hiroshi

Classifications

• A61B1/0655

  Control therefor · CPC title

• A61B1/000094

  extracting biological structures · CPC title

• A61B1/0646

  with illumination filters · CPC title

• A61B1/0653

  with wavelength conversion · CPC title

• A61B5/0075

  by spectroscopy, i.e. measuring spectra, e.g. Raman spectroscopy, infrared absorption spectroscopy (A61B5/0071 takes precedence) · CPC title