ENDOSCOPE APPARATUS AND METHOD FOR CONTROLLING FLUORESCENCE IMAGING APPARATUS

• US 20130096376A1
• Filed: 12/07/2012
• Published: 04/18/2013
• Est. Priority Date: 06/07/2011
• Status: Active Grant

• Current Assignee: Olympus Corporation
• Original Assignee: Olympus Medical Systems Corporation (Olympus Corporation)
• Inventors: TAKEI, Shunji, DOGUCHI, Nobuyuki
• Granted Patent: US 8,721,532 B2
• Time in Patent Office: Days
• US Class Current: 600/103
• CPC Class Codes: A61B 1/00006 of control signals
• CPC Class Codes: A61B 1/000095 for image enhancement
• CPC Class Codes: A61B 1/0005 combining images e.g. side-by-side, superimposed or tiled
• CPC Class Codes: A61B 1/043 for fluorescence imaging
• CPC Class Codes: A61B 1/063 for monochromatic or narrow-band illumination
• CPC Class Codes: A61B 1/0655 Control therefor
• CPC Class Codes: A61B 1/0661 Endoscope light sources
• CPC Class Codes: G01N 2021/6484 Optical fibres
• CPC Class Codes: G01N 21/6456 Spatial resolved fluorescence measurements; Imaging
• CPC Class Codes: G02B 2207/113 Fluorescence
• CPC Class Codes: G02B 23/2461 Illumination
• CPC Class Codes: H04N 23/555 for picking-up images in sites, inaccessible due to their dimensions or hazardous conditions, e.g. endoscopes or borescopes
• CPC Class Codes: H04N 23/74 by influencing the scene brightness using illuminating means
• CPC Class Codes: H04N 23/743 Bracketing, i.e. taking a series of images with varying exposure conditions

Abstract

An endoscope apparatus includes: a light source portion that irradiates an excitation light and a reference light alternately; an image pickup portion that picks up images of the fluorescence from the living tissue and the reflected light; a signal processing portion that generates image signals from picked up signals; an addition processing portion that generates, from image signals of fluorescence, addition processed signals of fluorescence in which pixels are added; a light quantity control portion that controls the quantity of light so as to maintain a predetermined light quantity ratio between the quantities of the excitation light and the reference light from the addition processed signals of fluorescence and image signals of the reflected light; and a superimposition processing portion that superimposes the addition processed signals and the image signals of the reflected light, with the predetermined light quantity ratio being maintained.

Claims

1. An endoscope apparatus comprising:

a light source portion including light sources that irradiate living tissue with an excitation light for generating fluorescence and a reference light for generating a reflected light alternately;

an image pickup portion including image pickup devices having a predetermined number of pixels for picking up images of the fluorescence generated by the irradiation of the living tissue with the excitation light and a reflected light of the reference light reflected by the living tissue;

a signal processing portion that generates image signals from signals picked up by the image pickup portion;

an addition processing portion that generates, from fluorescence signals obtained when the image of the fluorescence is picked up or the image signals of the fluorescence generated by the signal processing portion, addition processed signals of fluorescence in which a plurality of adjacent pixels are added;

a light quantity control portion that controls a quantity of at least one of the excitation light and the reference light so as to maintain a predetermined light quantity ratio between quantities of the excitation light and the reference light from the addition processed signals of the fluorescence and reflected light signals as the image signals of the reflected light on the basis of change in a number of pixels to be added in the addition processing portion; and

a superimposition processing portion that outputs, to a display portion, superimposed image signals in which the addition processed signals of the fluorescence and the reflected light signals are superimposed, with the predetermined light quantity ratio being maintained in the light quantity control portion.

2. The endoscope apparatus according to claim 1, further comprising

a number-of-pixels setting portion that sets a number of pixels to be added by the addition processing portion to generate a pixel signal of one pixel from a plurality of pixels, wherein if the number of pixels to be added is changed, the light quantity control portion controls the quantity of the excitation light on the basis of information on the number of pixels immediately after the number of pixels is changed.

3. The endoscope apparatus according to claim 2, wherein

the light quantity control portion includes a light adjustment portion that generates a light adjusting signal for controlling the quantities of the excitation light and the reference light of the light source portion to achieve predetermined brightness of the superimposed image signals with the predetermined light quantity ratio between the excitation light and the reference light of the light source portion being maintained, and

if the light adjustment portion determines that the quantity of the excitation light generated by the light source portion needs a value higher than an upper-limit value of the quantity of the excitation light in order to set the brightness of the superimposed image signals to the predetermined brightness, the light adjustment portion controls the addition processing portion to increase a present number of addition pixels J to a number of pixels K and change the quantity of the excitation light to J/K immediately after the number of pixels is increased.

4. The endoscope apparatus according to claim 3, further comprising

an image addition processing portion that performs addition processing of the image signals of the fluorescence among a plurality of (P) images picked up on a time-series basis, wherein the light adjustment portion controls the light quantity of the excitation light depending on an operation of the image addition processing portion.

5. The endoscope apparatus according to claim 2, wherein

the signal processing portion superimposes the addition processed signals of the fluorescence and the reflected light signals on one another to generate image signals in pseudo color as the superimposed image signals.

6. The endoscope apparatus according to claim 1, wherein

the light source portion includes a mode switch that switches between a fluorescence imaging mode in which living tissue is irradiated with the excitation light and the reference light and a normal imaging mode in which the living tissue is irradiated with a white color light, and

if the normal imaging mode is selected, the signal processing portion generates colored image signals from signals picked up by the image pickup portion and outputs the colored image signals to the display portion.

7. The endoscope apparatus according to claim 3, further comprising a movement detection portion that detects a movement amount for one frame from images among temporally different frames in the superimposed image signals, wherein depending on the detected movement amount value, the movement detection portion restrains an upper-limit value of the number of pixels added by the addition processing portion.

8. The endoscope apparatus according to claim 4, further comprising a movement detection portion that detects a movement amount for one frame from images among temporally different frames in the superimposed image signals, wherein depending on the detected movement amount value, the movement detection portion restrains an upper-limit value of the number of pixels added by the addition processing portion and an upper-limit value of the number of a plurality of (P) images added by the image addition processing portion.

9. The endoscope apparatus according to claim 3, further comprising an image addition processing portion that performs addition processing on the image signals of the fluorescence among a plurality of (P) images picked up on a time-series basis, wherein in response to changing of an operation of the image addition processing portion from an off state to an on state, the light adjustment portion controls a quantity of the excitation light to 1/P of a quantity of light in the off state.

10. The endoscope apparatus according to claim 7, wherein the movement detection portion further includes an evaluated number-of-pixels calculating portion that calculates from the movement amount value an evaluated number of pixels corresponding to the number of pixels moving for one frame.

11. The endoscope apparatus according to claim 8, wherein the movement detection portion further includes an evaluated number-of-pixels calculating portion that calculates from the movement amount value an evaluated number of pixels corresponding to the number of pixels moving for one frame, and if the evaluated number of pixels is a large value, the movement detection portion restrains an upper-limit value of the plurality (P) with which the image addition processing portion performs the addition processing, and if the evaluated number of pixels is a small value, the movement detection portion restrains an upper-limit value of the number of pixels added by the addition processing portion.

12. A method for controlling a fluorescence imaging apparatus, the method comprising:

a signal processing step in which a signal processing portion generates image signals from obtained fluorescence signals and reflected light signals reflected by living tissue;

a pixel addition processing step in which a pixel addition processing portion generates addition processed signals of fluorescence obtained by addition processing among a plurality of adjacent pixels from the fluorescence signals or the image signals of the fluorescence generated in the signal processing step;

a light adjusting signal generating step in which a light adjusting signal generating portion generates a light adjusting signal for controlling a quantity of at least one of the excitation light and the reference light by a light quantity control portion so as to maintain a predetermined light quantity ratio between quantities of the excitation light and the reference light from the addition processed signals of the fluorescence and reflected light signals as the image signals of the reflected light on the basis of change in the number of pixels to be added in the pixel addition processing step; and

a superimposition signal generating step in which a superimposition processing portion generates superimposed image signals in which the addition processed signals of the fluorescence and the reflected light signals are superimposed, with the predetermined light quantity ratio being maintained in the light adjusting signal generating step.

13. The method for controlling a fluorescence imaging apparatus according to claim 12, wherein

if the light adjusting signal generating step determines that a quantity of an excitation light by which a light source portion generates the fluorescence needs a value higher than an upper-limit value of the quantity of the excitation light in order to achieve predetermined brightness, the step increases a number of pixels J in present addition processing to a larger number of pixels K in the pixel addition processing step and generates a light adjusting signal for changing the quantity of the excitation light to J/K immediately after the number of pixels is increased.

14. The method for controlling a fluorescence imaging apparatus according to claim 13, further comprising

an image addition processing step in which an image addition processing portion performs addition processing of the image signals of the fluorescence among a plurality of (P) images picked up on a time-series basis, wherein the light adjusting signal generating step generates a light adjusting signal for controlling the light quantity of the excitation light depending on an operation in the image addition processing step.

15. The method for controlling a fluorescence imaging apparatus according to claim 13, further comprising

a movement detecting step in which a movement detection portion detects a movement amount for one frame from images among temporally different frames in the superimposed image signals, wherein depending on the detected movement amount value, the movement detecting step restrains an upper-limit value of the number of pixels added in the pixel addition processing step.

16. The method for controlling a fluorescence imaging apparatus according to claim 14, further comprising

a movement detecting step in which a movement detection portion detects a movement amount for one frame from images among temporally different frames in the superimposed image signals, wherein depending on the detected movement amount value, the movement detecting step restrains an upper-limit value of the number of pixels added in the pixel addition processing step and an upper-limit value of the number of a plurality of (P) images added in the image addition processing step.