Endoscope system for fluorescent observation

Abstract

An endoscope system is disclosed for detecting fluorescent light emitted in the near-infrared region by a plurality of fluorescent labeling materials introduced into a living tissue. An illumination system generates illumination light in the wavelength range 600 nm-2000 nm which serves as excitation light for the plurality of fluorescent labeling materials, and a detection system that can separately detect different ones of the plurality of fluorescent light emissions that are emitted at different wavelengths from among the plurality of fluorescent labeling materials is provided. The endoscope system may include a conventional-type endoscope having an insertion section, or a capsule endoscope that wirelessly transmits image data. By superimposing the image data obtained using reflected light in the visible region and fluorescent light emitted by the fluorescent labeling materials, improved diagnostic capabilities are provided.

Description

This application claims the benefit of priority of JP 2003-172361, filed in Japan on Jun. 15, 2003, and of JP 2004-176198, filed in Japan on Jun. 14, 2004, the subject matters of which are hereby incorporated by reference. BACKGROUND OF THE INVENTION Prior art endoscopes have conventionally been used in diagnosis and treatment where a fluorescent substance having an affinity to a lesion, such as cancer, has been previously administered into a subject's body and excitation light that excites the fluorescent substance is then irradiated onto tissue of the subject so that fluorescent emissions from the fluorescent substance that deposits at the lesion can be detected. For example, Japanese Laid-Open Patent Application H10-201707 describes a prior art endoscope wherein indocyanine green derivative labeled antibodies have been previously introduced into the living tissue. The lesions then emit fluorescent light when excited by infrared light, with the infrared light being readily tran...

AI Technical Summary

Problems solved by technology

However, cancer cells in the earliest stage show only meager morphologic changes from normal cells, and thus, conventional techniques that focus primary on morphologic changes in cells for determining the presence of cancer are not applicable for detecting cancer in the earliest stage.

In addition, living tissue scatters light in a sufficiently intense manner that the living tissue layer above the cancerous region blocks observation of the cancer.

This becomes a remarkably adverse factor in solving the problem of detecting cancer in the earliest stage.

Of course, the fact that the tissues to be observed are within a living body is also an adverse factor.

However, the resolution of these devices is not yet sufficient to enable cancer to be detected in its earliest stage or to enable a diagnosis to be made of whether the cancer has become malignant.

Living tissue scatters light in a sufficiently intense manner that illuminated living tissue is difficult to see through.

However, living tissue rarely scatters or absorbs significant amounts of light in the near-infrared to infrared range.

In prior art endoscopes, the wavelength used can be varied only by varying the wavelength of the light source, and thus a technique for separating plural wavelengths in the near-infrared range is not available in the detection component.

Therefore, in prior art endoscopes, plural fluorescent wavelengths that emit fluorescence in the near-infrared range when excited by illumination cannot be detected even when such labels have been previously introduced into living tissue that is to be observed.

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