JP4008184B2 - Fluorescence detection device - Google Patents

Description

一方、蛍光差成分Ifλ₋は、

次いで、蛍光差成分Ifλ_ー と蛍光和成分Ifλ_＋ との除算を除算手段５で行う。蛍光差成分Ifλ_ー と蛍光和成分Ifλ_＋ との除算を行うと、

となる。即ち、本構成においても励起光照度の場所による不均一さIλ_ｅｘ がキャンセルされる。X の値は自家蛍光分子濃度で規格化した薬剤蛍光分子濃度を表しており、Ifλ_ー / Ifλ_＋ が大きいということは薬剤蛍光が弱いことを示し正常部位であることを示し、逆にIfλ_ー / Ifλ_＋ が小さくなると薬剤蛍光が強いことを示し病変部であることを意味する。このように蛍光差成分Ifλ_ー と蛍光和成分Ifλ_＋ との間で除算演算を行うことによっても、病変部を特異的に抽出することが可能となる。この際、分母に蛍光和成分Ifλ_＋ を用いることにより分母を大きくすることができ、ゼロ割り算に伴う演算エラーの発生を抑えることができる。
【００４７】
上記説明は、薬剤蛍光検出の場合について説明したが、自家蛍光検出の場合にも同様に適用が可能であるのは言うまでもない。この場合において、上記説明における「蛍光差成分」は、短波長成分（例えば、緑色領域成分Ｇ）と長波長成分（例えば、赤色領域成分Ｒ）との蛍光差成分（Ｇ−Ｒ）」と、「蛍光和成分」は、短波長成分（例えば、緑色領域成分Ｇ）と長波長成分（例えば、赤色領域成分Ｒ）との蛍光和成分（Ｇ＋Ｒ）」として考える。
【００４８】
上記説明は、いずれも蛍光和成分との除算を行う場合について説明したが、励起光によって励起されたおよそ全領域の蛍光成分（全蛍光成分）との除算を行う場合についても同様に適用が可能である。以下に、この場合について詳細に説明する。最初に、自家蛍光検出の場合であって、短波長成分（例えば、緑色領域成分Ｇ）と長波長成分（例えば、赤色領域成分Ｒ）との蛍光差成分（Ｇ−Ｒ）と、全蛍光成分との除算に適用する場合について説明する。
【００４９】
上述の蛍光和成分の場合と同様に、生体観察部10から生じた蛍光L3を集光光学系２で集光し、ダイクロイックミラーや光学フィルタ等によって生体観察部10から発せられる短波長成分と長波長成分との蛍光差成分と、短波長成分から長波長成分までの全蛍光成分に波長分離され、蛍光検出手段３が蛍光差成分を検出し、蛍光検出手段４が全蛍光成分を検出する。その他の構成は、上述の場合と同様である。尚、上述の場合と同様に、蛍光差成分を検出する手段および全蛍光成分を検出する手段は本構成例に限定されるものではなく、所定の波長領域に波長分離して検出し、その検出結果を加減算等の演算を行うことによって最終的に必要とする波長領域の蛍光成分を求めても良いのは言うまでもない。特に、全蛍光成分を検出する手段としては、短波長成分と長波長成分との波長分離特性を工夫する（例えば短波長成分の長波長側の遮断特性と長波長成分の短波長側の遮断特性とを同一にする等）ことによって、短波長成分と長波長成分に波長分離して検出しその結果を加算して蛍光和成分を求めることにより、この蛍光和成分を全蛍光成分として考えることも可能である。すなわち、この場合は、上記説明の蛍光和成分との除算を行う構成がそのまま全蛍光成分との除算を行う構成として機能させることができることとなる。以下同様である。
【００５０】
以下、上記構成の蛍光検出装置の作用について詳細に説明する。蛍光検出手段３および４により検出された各々の波長成分は以下のように表される。上記説明で明らかなように、蛍光差成分Ifλ₋ は、

一方、短波長領域から長波長領域までの全蛍光成分Ifλ_１２は、
Ifλ_１２＝ kλ_１２・Iλ_ｅｘ・ηFλ_１２・M・ηD
次いで、蛍光差成分Ifλ_ー と全蛍光成分Ifλ_１２との除算を除算手段５で行う。蛍光差成分Ifλ_ー と蛍光和成分Ifλ_１２ との除算を行うと、

となる。但し、C_１ および C_２ は定数である。
【００５１】
即ち、本構成においても、励起光照度の場所による不均一さIλ_ｅｘ がキャンセルされる。ここで、Ifλ_ー / Ifλ_１２が大きいということは短波長領域の蛍光が強いことを示し正常部位であることを示し、逆にIfλ_ー / Ifλ_１２が小さくなると短波長領域の蛍光が弱いことを示し病変部であることを意味する。このように蛍光差成分Ifλ_ー と全蛍光成分Ifλ_１２との間で除算演算を行うことによっても、病変部を特異的に抽出することが可能となる。この際、分母に全蛍光成分Ifλ_１２を用いることにより分母を大きくすることができ、ゼロ割り算に伴う演算エラーの発生を抑えることができる。
【００５２】
上記説明は、自家蛍光検出の場合であって、短波長成分（例えば、緑色領域成分Ｇ）と長波長成分（例えば、赤色領域成分Ｒ）との蛍光差成分（Ｇ−Ｒ）と、全蛍光成分との除算に適用する場合について説明したが、長波長成分（例えば、赤色領域成分Ｒ）と全蛍光成分との除算を行う場合についても同様に適用が可能であるのは言うまでもない。この場合において、上記説明における「蛍光差成分」は「長波長成分」として考える。
【００５３】
また、上記説明は自家蛍光検出の場合についてのものであるが、薬剤蛍光検出の場合についても同様に適用が可能であるのは言うまでもない。この場合において、上記説明における「短波長成分と長波長成分との蛍光差成分と全蛍光成分との除算」は「自家蛍光成分Inと薬剤蛍光成分Exとの蛍光差成分（In−Ex）と全蛍光成分との除算」と、「長波長成分と全蛍光成分との除算」は、「薬剤蛍光成分Exと全蛍光成分との除算」として考える。
【００５４】
次に本発明による蛍光検出装置を適用した具体的な実施の形態の一例について説明する。図６は本発明による蛍光検出装置を適用した内視鏡装置の概略構成図であり、本内視鏡は、蛍光診断薬が予め注入された生体観察部に励起光を照射することにより発せられる蛍光を検出し、赤色蛍光成分と、青色蛍光成分、緑色蛍光成分および赤色蛍光成分との蛍光和成分との除算を行うものである。
【００５５】
本発明の第三の実施の形態にかかる上記内視鏡装置は、患者の病巣と疑われる部位に挿入される内視鏡100 、通常観察用白色光および蛍光像観察用励起光を発する光源を備える照明装置110 、通常観察時に前記白色光の生体被照射部位からの反射光および蛍光像観察時に前記励起光の生体被照射部位からの蛍光を検出する蛍光検出手段としての高感度カメラユニット300 、検出された反射光像あるいは蛍光像の画像処理を行う画像処理装置310 、および該画像処理装置310 で処理された画像情報を可視画像として表示するディスプレイ160 から構成されている。
【００５６】
内視鏡100 は、内視鏡挿入部101 内部に該内視鏡挿入部101 の先端まで延びるライトガイド106 およびイメージファイバ104 を備えており、該ライトガイド106 とイメージファイバ104 の先端部即ち内視鏡挿入部101 先端部には、それぞれ、照明レンズ102 、対物レンズ103 を備えている。前記ライトガイド106 の一端は照明装置110 から操作部105 をつなぐ接続部107 を通り照明装置110 内へ達している。前記イメージファイバ104 の一端は操作部105 内に延び、接眼レンズ109 を有する接眼部108 に接している。
【００５７】
前記照明装置110 は、通常像観察用の白色光L2を発するキセノンランプ118 、蛍光観察用の励起光L1を発する水銀ランプ111 、該水銀ランプ111 から発せられた励起光L1の透過波長を設定する光学フィルタ112 、および通常観察時と蛍光観察時とで白色光L2と励起光L1を切り換えるためドライバ116 により駆動される切換ミラー115 からなる。
【００５８】
高感度カメラユニット300 は、透過する反射光および蛍光L3の励起光成分をカットする励起光シャープカットフィルタ302 と、該フィルタ302 を透過した反射光および蛍光L3による像を結像する撮像手段としての冷却CCD カメラ303 とからなり、冷却CCD カメラ303 の検出面には図７にその模式図を示す色モザイクフィルタ304 が装着されている。色モザイクフィルタ304 は蛍光をＲ、Ｇ、Ｂの各色の波長領域に分離する微少なフィルタＲ、Ｇ、Ｂから構成され、各フィルタの光学的透過特性は図８に示す通りである。
【００５９】
画像処理装置310 は、冷却CCD カメラ303 で得られた映像信号をデジタル化するA/D 変換回路311 、デジタル化されたRGB 各々の画像信号を保存するR 画像メモリ314 、G 画像メモリ313 、B 画像メモリ312 、各画像メモリの出力を加算処理して得られる蛍光和成分を反映する加算信号を保存する加算メモリ315 、R 画像メモリ314 の出力と加算メモリ315 の出力との除算処理を行い除算結果を保存する除算メモリ316 、該除算メモリ316 に保存された除算画像信号をディスプレイ160 に可視画像として表示するための画像処理を行うビデオ信号発生回路317 、照明装置110 と光路切換ユニット120 との切換ミラー115,121 を駆動するドライバ116,123 に信号を送るタイミングコントローラ319 、および該タイミングコントローラ319 を制御するビデオプロセッサ318 からなる。
【００６０】
以下、本発明による蛍光検出装置を適用した上記構成の内視鏡装置の作用について説明する。最初に、本内視鏡装置の通常像観察時の作用を説明する。
【００６１】
通常観察時には、照明装置110 内の切換ミラー115 は、タイミングコントローラ158 からの信号に基づきドライバ116 によって駆動されて白色光L2の進行を妨害しないように破線の位置に移動する。キセノンランプ118 から出力される白色光L2は、レンズ117 を経て切換ミラー115 へ向かう。前記白色光L2はレンズ114 によってライトガイド106 に入力され、内視鏡先端部まで導光された後、照明レンズ102 から病変部11を含む観察部10へ照射される。
【００６２】
生体に照射された白色光L2の反射光は対物レンズ103 よって集光され、イメージファイバ104 、接眼部108 内に設けられた接眼レンズ109 を経て、高感度カメラユニット300 へ向かう。接眼レンズ109 を透過した白色光L2の反射光は、レンズ301 、および励起光シャープカットフィルタ302 を透過し、冷却CCD カメラ303 へ結像する。なお、冷却CCD カメラ303 の検出面には、色モザイクフィルタ304 が装着されているため、色モザイクフィルタ304 を透過した光は、Ｒ、Ｇ、Ｂの各色の波長領域に分離される。冷却CCD カメラ303 からの映像信号はA/D 変換回路311 へ入力され、RGB の各映像信号成分についてデジタル化された後、それぞれ、R 画像メモリ314 、G 画像メモリ313 、B 画像メモリ312 へ保存される。R 画像メモリ314 、G 画像メモリ313 、B 画像メモリ312 へ保存された通常画像信号は、ビデオ信号発生回路317 によってDA変換後にカラーマトリックス処理およびエンコード処理され、NTSC信号としてディスプレイ160 へ入力され、該ディスプレイ160 に可視画像として表示される。
【００６３】
次いで、蛍光像観察時の作用を説明する。ここでは、蛍光診断薬としてλ_ｅｍ＝635nm 前後の蛍光を発する5-ALA を用いる場合について説明する。生体の被照射部には予め前記蛍光診断薬5-ALA が投与される。
【００６４】
切換ミラー115 はタイミングコントローラ158 からの信号に基づき、ドライバ116 によって駆動されて白色光L2の通過を遮断すると共に励起光L1を反射するように実線の位置に移動する。水銀ランプ111 から出力される励起光L1は、光学フィルタ112 およびレンズ113 を透過し、切換ミラー115 へ向かう。切換ミラー115 で反射された励起光L1は、レンズ114 によってライトガイド106 に入力され、内視鏡先端部まで導光された後、照明レンズ102 から病変部11を含む観察部10に照射される。なお、光学フィルタ112 は、図９に示すような透過特性をしており光学フィルタ112 を透過した水銀ランプ111 から発せられる励起光L1は、波長405nm の輝線スペクトルとなる。
【００６５】
励起光を照射されることにより生じる生体観察部10からの蛍光L3は、対物レンズ103 よって集光され、イメージファイバ104 および接眼レンズ109 を経て、励起光シャープカットフィルタ302 を透過し励起光成分が除去された後、冷却CCD カメラ303の検出面に装着された色モザイクフィルタ304 によりＲ、Ｇ、Ｂの各色の波長領域に分離されて、冷却CCD カメラ303 へ結像される。なお、通常観察光に比べて蛍光強度は弱いので、蛍光像観察時においては冷却CCD カメラ303 の撮像レートを通常像観察時より充分遅くする。冷却CCD カメラ303 からの蛍光映像信号はA/D 変換回路311 へ入力され、R 画像、G 画像、B 画像各々についてデジタル化された後、それぞれ、R 画像メモリ314 、G 画像メモリ313 、B 画像メモリ312 へ保存される。RGB 蛍光像を反映する各々の映像信号が取得された後、加算メモリ315 において、R 画像メモリ314 、G 画像メモリ313 およびB 画像メモリ312 の出力の加算処理が行われ、加算結果が蛍光和成分を反映する加算信号として加算メモリ315 に保存される。生体からの蛍光はR 映像信号が主として薬剤蛍光を反映し、BG映像信号が主として自家蛍光を反映するため、前記加算結果が、自家蛍光と薬剤蛍光との和を表す。
【００６６】
次いで、除算メモリ316 において、R 画像メモリ314 の出力と加算メモリ315 の出力との除算処理が行われ、除算結果が除算メモリ316 に保存される。除算メモリ316 へ保存された除算画像信号は、ビデオ信号発生回路317 によってDA変換後にエンコード処理され、ディスプレイ160 に可視画像として表示される。なお、通常画像を保存するメモリを上記RGB メモリと別に設けることにより、除算画像と通常画像をオーバーレイ表示することもできる。
【００６７】
また、水銀ランプ111 に対しては、上記光学フィルタ112 とは異なる透過特性の光学フィルタを用いることが可能であり、例えば、図10に示すように405nm と365nm の輝線を選択的に透過させることができる光学フィルタを用いてもよい。405nm は蛍光診断薬を高効率で励起することができる波長λ_ｅｘ１ 、365nm は自家蛍光分子を高効率で励起することができる波長λ_ｅｘ２ であるので、このような２種の光を併せて用いることはＳＮ比向上のために望ましい。以下薬剤蛍光検出の場合において同様である。
【００６８】
尚、本構成にあっては、自家蛍光はG 領域が強いので、自家蛍光成分と薬剤蛍光成分との和を求める際に、G 画像メモリ313 の出力とR 画像メモリ314 の出力との加算処理に代えても良い。
【００６９】
さらに、本構成における色モザイクフィルタ304 の波長分離特性が図８に示すものであり、蛍光和成分を求めることは全蛍光成分を求めることと実質的に等価と考えることができる。この場合において、色モザイクフィルタ304 の波長分離特性を変えることにより（例えば各色の遮断特性がオーバーラップしないようにする等）、全蛍光成分と等価とならない蛍光和成分との除算を行うものとして機能させることもできる。
【００７０】
また、本内視鏡装置は蛍光検出手段である高感度カメラユニット300 の蛍光検出面に色モザイクフィルタ304 が装着され、該色モザイクフィルタ304 により、蛍光が所望の波長領域に分離されているので、高感度カメラユニット300 の構成を簡易化することができる。
【００７１】
またそのため、内視鏡先端部に色モザイクフィルタ304 が装着されたCCD カメラを配置することが容易に可能であり、すなわち内視鏡先端部に撮像素子を具備する電子内視鏡として適用することができる。
【００７２】
さらに、上記実施の形態にかかる装置に使用されているシャープカットフィルタは所望の励起光波長に応じて適宜変更可能である。
【００７３】
また、上記実施の形態の説明は、いずれも薬剤蛍光検出を行う場合についてのものであるが、自家蛍光検出を行う自家蛍光画像診断装置に適用可能なことは言うまでもなく、上記実施の形態の構成にほぼそのまま適応できる。但し、励起光としては、生体内在色素の励起ピーク波長近辺の領域の波長の光を用いればよい。
【００７４】
また、上記具体的な実施の形態の説明は薬剤蛍光成分又は長波長成分（例えば赤色成分Ｒ）を除算する場合についてのものであるが、蛍光差成分（（In−Ex）又は（Ｇ−Ｒ））を除算する場合についても適用可能である。
【図面の簡単な説明】
【図１】本発明による蛍光検出装置の基本構成図
【図２】励起波長λ_ｅｘと、自家蛍光Ifλ_２と、薬剤蛍光Ifλ_１との関係を示す原理説明図
【図３】薬剤蛍光Ifλ_１と全蛍光Ifλ との除算Ifλ_１/ Ifλと、自家蛍光分子濃度で薬剤蛍光分子濃度を規格化した変数 N/n＝X との関係を示す原理説明図
【図４】励起波長λ_ｅｘ１および励起波長λ_ｅｘ２における自家蛍光Ifλ_２，Ifλ_２'と薬剤蛍光Ifλ_１，Ifλ_１'との関係を示す原理説明図
【図５】薬剤蛍光Ifλ_１と全蛍光Ifλとの除算Ifλ_１/If＝(Ifλ_１+Ifλ_１')/(Ifλ_１+Ifλ_１'+Ifλ_２+Ifλ_２')と、自家蛍光分子濃度で薬剤蛍光分子濃度を規格化した変数 N/n＝X との関係を示す原理説明図
【図６】本発明による蛍光検出装置を適用した具体的な実施の形態である内視鏡装置の概略構成図
【図７】上記実施の形態にかかる内視鏡装置に使用される高感度カメラに用いられる色モザイクフィルタを示す説明図
【図８】上記色モザイクフィルタの光透過特性図
【図９】上記実施の形態の励起光光源の励起光スペクトルを示す説明図
【図１０】上記実施の形態の励起光光源の励起光スペクトルの他の態様を示す説明図
【図１１】自家蛍光の蛍光スペクトルを示す説明図
【符号の説明】
１ 励起光照射手段
２ 集光光学系
３ 蛍光検出手段
４ 蛍光検出手段
５ 除算手段
６ 表示手段
L1 励起光
L3 蛍光
100 内視鏡
104 イメージファイバ
106 ライトガイド
110 照明装置
111 水銀ランプ
115 切換ミラー
118 キセノンランプ
160 ディスプレイ
300 高感度カメラユニット
303 冷却CCD カメラ
304 色モザイクフィルタ
310 画像処理装置
311 Ａ／Ｄ変換回路
316 除算画像メモリ
317 ビデオ信号発生回路
318 ビデオプロセッサ
319 タイミングコントローラ[0001]
BACKGROUND OF THE INVENTION
The present invention irradiates an observation part of a living body into which a photosensitive substance that emits fluorescence with strong affinity for a tumor is previously injected, and the intensity of the fluorescence emitted from the photosensitive substance and the in vivo dye at that time. The present invention relates to a fluorescence detection apparatus that can be applied to a fluorescence diagnosis apparatus that diagnoses a tumor based on the intensity of autofluorescence emitted from a living body dye without diagnosing a tumor or injecting a photosensitive substance in advance.
[0002]
[Prior art]
Conventionally, various researches on photodynamic diagnosis generally called PDD (Photodynamic Diagnosis) have been made. This PDD has a tumor affinity, and a photosensitizer (ATX-S10, 5-ALA, NPe6, HAT-D01, Photofrin-2, etc.) that emits fluorescence when excited by light is used as a fluorescent diagnostic agent. It is absorbed in advance in a tumor part such as cancer in the living body, and the part is irradiated with excitation light in the excitation wavelength region of the photosensitive substance to generate fluorescence from the fluorescent diagnostic agent accumulated in the tumor part, and this fluorescence is received. This is a technique for diagnosing a tumor part by displaying the localization / infiltration range of a lesion as an image.
[0003]
For example, Japanese Patent Publication No. 63-9464, Japanese Patent Application Laid-Open No. 1-136630, and Japanese Patent Application Laid-Open No. 7-59783 disclose a fluorescent diagnostic apparatus for performing this PDD. This type of fluorescence diagnostic device basically has an excitation light irradiation means for irradiating the living body with excitation light in the excitation wavelength region of the photosensitive substance, and detects fluorescence emitted from the photosensitive substance to generate a fluorescent image of the living body. It consists of a means for imaging and an image display means for receiving the output of this imaging means and displaying the fluorescent image, and is often incorporated in an endoscope inserted in a body cavity, a surgical microscope, etc. Configured.
[0004]
In addition, without injecting a photosensitive substance into the living body in advance, the living body observation part (living body irradiated part) is irradiated with excitation light in the excitation wavelength region of the living body dye, and fluorescence emitted from the living body dye is received. Accordingly, a technique for diagnosing a tumor part by displaying the localization / infiltration range of a lesion as an image has been proposed.
[0005]
Furthermore, the fluorescence intensity can be diagnosed as to whether or not the point is a tumor part by detecting the fluorescence intensity for each point on the living body part without taking a two-dimensional fluorescence image as described above. A diagnostic device has also been proposed (for example, Japanese Patent Application No. 7-252295).
[0006]
By the way, in the fluorescence diagnostic apparatus as described above, the distance from the excitation light irradiation system to the living body observation part is not uniform because the part of the living body is uneven, and the excitation light illuminance at the excitation light irradiation part of the living body is generally non-uniform. is there. In general, the fluorescence intensity is approximately proportional to the excitation light illuminance, and the excitation light illuminance decreases in inverse proportion to the square of the distance. Therefore, the normal part nearer to the lesion part far from the light source emits stronger fluorescence, or the fluorescence from the lesion part at a position inclined with respect to the excitation light is extremely reduced. When the illuminance of the excitation light is non-uniform in this way, the fluorescence intensity changes according to the level of the illuminance of the excitation light, which may cause erroneous diagnosis of the tumor part.
[0007]
Therefore, in order to compensate for such a change in fluorescence intensity due to the non-uniformity of the distance to the living body observation unit, for example, as disclosed in Japanese Patent Application Laid-Open No. 62-247232, Japanese Patent Publication No. 3-58729, etc. A fluorescence diagnostic apparatus is provided. In the fluorescence diagnostic apparatus described in Japanese Examined Patent Publication No. 3-58729, the fluorescent light generated by irradiating a part of a living body into which a photosensitive substance having a strong affinity for a lesion is previously injected with excitation light is received and the excitation light. The reflected light is received, and image calculation based on the division of the fluorescent component and the reflected light component is performed, and the term due to the distance from the living body observation unit is eliminated by such division. However, since the term relating to the reflectance of the excitation light irradiated portion remains in the division result of the fluorescent component and the reflected light component, a fluorescent image reflecting the distribution of the fluorescent diagnostic agent cannot be obtained as a result. Still remains.
[0008]
On the other hand, in the apparatus shown in “FLUORESCENCE IMAGING OF EARLY LUNG CANCER” (Annual International Conference of the IEEE Engineering and Biology Society, Vol.12, No.3, 1990) The autofluorescence generated from the living body dye is separated into a component in the green wavelength region (hereinafter referred to as “green region component G”) and a component in the red wavelength region (hereinafter referred to as “red region component R”). Then, image calculation based on the division between the red region component R and the green region component G is performed, and the division result is displayed. This is because the autofluorescence spectrum is different between the normal part and the lesioned part, that is, the autofluorescence spectrum emitted by the in-vivo dye in the normal part is extremely decreased in the lesioned part, especially in the green region compared to the normal part. Therefore, the lesion uses the fact that the reduction rate of the green region component G of autofluorescence is very large compared to the reduction rate of the red region component R, and the fluorescence from the lesion is divided by the division of R / G. It can be extracted specifically and displayed as an image. In this apparatus, the fluorescence intensity term depending on the distance between the excitation light source and the fluorescence light receiving unit and the living body observation unit is canceled, but the S / N ratio is extremely low because the autofluorescence at the lesion is extremely small. There's a problem.
[0009]
Therefore, in the "Fluorescence imaging diagnosis of cancer using Red / Green Ratio" (Tokyo Medical University, Hamamatsu Photonics) announced at the 16th Annual Meeting of the Laser Society of Japan in 1995, red fluorescence accumulated at the lesion. It has been proposed to amplify the red fluorescence intensity in the lesioned area and perform the R / G calculation using a fluorescent diagnostic agent that emits. As a result, a fluorescence image in which the fluorescence intensity from the lesion is amplified as compared with the apparatus shown in the above-mentioned “FLUORESCENCE IMAGING OF EARLY LUNG CANCER” is obtained.
[0010]
By performing the calculation of R / G as in both cases, the fluorescence intensity term depending on the distance between the excitation light source and the fluorescence light receiving unit and the living body observation unit irradiated with the excitation light can be ignored.
[0011]
[Problems to be solved by the invention]
However, since the green autofluorescent component in the lesion is extremely weak, there is still a problem that any of the above methods may cause division by zero and easily cause a calculation error.
[0012]
The present invention has been made in view of the above problems, and fluorescence that corrects the fluorescence intensity depending on the distance between the excitation light source and the fluorescence light receiving unit and the living body observation unit irradiated with the excitation light so as not to cause a calculation error. An object of the present invention is to provide a detection device.
[0013]
[Means for Solving the Problems]
The first fluorescence detection apparatus according to the present invention irradiates a living body observation part preliminarily injected with a light-sensitive substance (fluorescence diagnosis) that emits fluorescence, and detects fluorescence generated from the observation part. An apparatus for detecting fluorescence, the excitation light irradiation means for irradiating excitation light in the excitation wavelength region of the fluorescent diagnostic agent and the indigenous dye that emits fluorescence, and drug fluorescence ("" All fluorescent components including the wavelength region of autofluorescence emitted from the living body dye, or part of the wavelength region of drug fluorescence emitted from the fluorescent diagnostic agent. One of a fluorescent component of a wavelength region and a fluorescent sum component of a fluorescent component of a part of the wavelength region of the autofluorescent wavelength region emitted from the living body dye, and the wavelength region of the drug fluorescence Fluorescence component in a part of the wavelength region, or fluorescence difference between a part of the wavelength region of the drug fluorescence and a part of the autofluorescence wavelength region. Fluorescence detection means for extracting any one of the components, division for dividing any one of the total autofluorescence component or the fluorescence sum component extracted by the fluorescence detection means, and either the fluorescence component or the fluorescence difference component And the fluorescence detection means separates the fluorescence emitted from the observation unit into either the whole autofluorescence component or the fluorescence sum component and the fluorescence component or the fluorescence difference component A mosaic filter; and an imaging unit that two-dimensionally detects fluorescence transmitted through the color mosaic filter, and the color mosaic filter is mounted on a fluorescence detection surface of the imaging unit. It is characterized in.
[0014]
In this case, in order to improve the S / N ratio of the fluorescence component extracted by the fluorescence detection means, the excitation light uses light in a wavelength region near the excitation peak wavelength of the fluorescence diagnostic agent, It is desirable to use light in a wavelength region near the excitation peak wavelength and light in a wavelength region near the excitation peak wavelength of the in vivo dye.
[0015]
The “excitation peak wavelength” is “the wavelength of excitation light that gives the strongest intensity of fluorescence (or autofluorescence) emitted by the excitation light from the fluorescent diagnostic agent and / or the living body dye”. is there. The same applies hereinafter.
[0016]
In addition, the second fluorescence detection apparatus according to the present invention irradiates the living body observation part into which the photosensitive substance (fluorescent diagnostic agent) is not injected with excitation light, and thereby emits the self emitted from the living body dye of the observation part. A fluorescence detection device for detecting fluorescence, the excitation light irradiation means for irradiating the observation part of the living body with the excitation light in the excitation wavelength region of the fluorescent substance that emits fluorescence, and emitted from the biological dye of the observation part All of the autofluorescent components in the visible region including a relatively short wavelength region and a relatively long wavelength region of the autofluorescent components, or a relatively short wavelength region of the autofluorescent components emitted from the in-vivo dye of the observation unit Any one of a fluorescent sum component of a fluorescent component in a predetermined wavelength region in the region and a fluorescent component in a predetermined wavelength region in a relatively long wavelength region in the autofluorescence, and a relative component in the autofluorescent component Long A fluorescent component in a part of the wavelength region of the wavelength region, or a fluorescent component of a part of the wavelength region in the relatively short wavelength region of the autofluorescent component and a relatively long wavelength of the autofluorescent component A fluorescence detection means for extracting any one of the fluorescence difference components from the fluorescence component in a part of the wavelength region of the area, and either the total autofluorescence component or the fluorescence sum component extracted by the fluorescence detection means, Division means for performing division with either the fluorescence component or the fluorescence difference component, and the fluorescence detection means converts the fluorescence emitted from the observation unit to either the total autofluorescence component or the fluorescence sum component. A color mosaic filter that separates into either the fluorescent component or the fluorescent difference component, and an imaging unit that two-dimensionally detects the fluorescence transmitted through the color mosaic filter. Filter in which is characterized in that it is mounted on the fluorescent detection surface of the image pickup means.
[0017]
In this case, in order to improve the S / N ratio of the fluorescence component extracted by the fluorescence detection means, it is desirable to use light in the wavelength region near the excitation peak wavelength of the living dye as the excitation light.
[0018]
【The invention's effect】
According to the first and second fluorescence detection apparatuses according to the present invention described above, by performing a division operation using the total autofluorescence component over a predetermined wavelength region or the fluorescence sum component of a desired wavelength region as a denominator, Since the denominator for division can be made sufficiently large, there is no calculation error of dividing by zero in image calculation, and the excitation light source and the fluorescence light receiving unit and the living body observation unit irradiated with the excitation light are not affected. It is possible to stably remove the fluctuation of the fluorescence intensity due to the distance.
[0019]
Since the denominator and numerator for division can be made sufficiently large by using light in the wavelength region near the excitation peak wavelength of the in vivo dye and / or fluorescent diagnostic agent as the excitation light, the SN ratio is high. Arithmetic processing is possible.
[0020]
In addition, by applying to a fluorescence diagnostic apparatus that observes a fluorescence image using an imaging means such as an imaging device as a fluorescence detection means, a fluorescence image from which fluctuations in fluorescence intensity due to the distance are removed can be obtained, In addition, since a good image with a high S / N ratio can be obtained, it is possible to improve the diagnostic performance.
[0021]
Furthermore, the configuration of the fluorescence detection means is simplified by separating the fluorescence into a desired wavelength region using the color mosaic filter.
[0022]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a basic configuration of a fluorescence detection apparatus according to the present invention. The fluorescence detection apparatus having this basic configuration includes an excitation light irradiating means 1 that irradiates the living body observation unit 10 with the excitation light L1, and a fluorescent light L3 generated from the living body observation unit 10 after being condensed by the condensing optical system 2, and then a desired one. Fluorescence detection means 3 for extracting a fluorescent component in a desired wavelength region by separating and detecting the wavelength region, and all fluorescent components over a predetermined wavelength region of fluorescence (or autofluorescence) excited by excitation light or desired It comprises fluorescence detection means 4 for extracting a fluorescence sum component in the wavelength region, and division means 5 for performing a division operation based on the outputs of the fluorescence detection means 3 and 4. The output of the division means 5 is, for example, image information. Is input to the display means 6 for displaying a visible image. Needless to say, the fluorescence detection means 3 and 4 may be considered as fluorescence detection means including the condensing optical system 2, and in this configuration example, they are merely separated for convenience of explanation.
[0023]
Hereinafter, in the fluorescence detection apparatus having the above basic configuration, a method for correcting the fluorescence intensity depending on the distance between the excitation light source and the fluorescence light receiving unit and the living body observation unit irradiated with the excitation light will be described in detail.
[0024]
First, the living body observation part into which a photosensitive substance (fluorescent diagnostic agent) is previously injected is irradiated with excitation light, and the resulting fluorescence from the fluorescent diagnostic agent and autofluorescence from the in vivo dye are detected. A fluorescence detection apparatus (hereinafter referred to as “drug fluorescence detection”), which is applied to division of a drug fluorescence component Ex and a fluorescence sum component (Ex + In) of the drug fluorescence component Ex and the autofluorescence component In explain.
[0025]
Excitation wavelength λ from excitation light irradiation means 1_exThe living body observation unit including the lesioned part of the living body to which the fluorescent diagnostic agent has been administered in advance is emitted. As a result, the fluorescence L3 generated from the biological observation unit 10 is collected by the condensing optical system 2, and the drug fluorescent component emitted from the fluorescent diagnostic agent of the biological observation unit 10 by the dichroic mirror, the optical filter, etc. The wavelength is separated into the fluorescence sum component with the fluorescence component, the fluorescence detection means 3 detects the drug fluorescence component, and the fluorescence detection means 4 detects the fluorescence sum component. Needless to say, the light detection element used in the fluorescence detection means 3 and 4 may be a light detection element such as a photodiode for detecting the fluorescence L3 point by point, and the fluorescence L3 is detected two-dimensionally to obtain a fluorescence image. A CCD image sensor for imaging may be used. The same applies hereinafter.
[0026]
Further, the wavelength region of the “drug fluorescence component” and the wavelength region of the “drug fluorescence component included in the fluorescence sum component” are not necessarily the same. Furthermore, the means for detecting the fluorescent component of the drug and the means for detecting the fluorescent sum component are not limited to this configuration example. The detection is performed by separating the wavelength into a predetermined wavelength region, and the detection result is subjected to operations such as addition and subtraction. It is possible to obtain a fluorescent component in a wavelength region that is finally required by performing the process. For example, wavelength separation is performed on the drug fluorescence component and the autofluorescence component, the fluorescence detection means 3 detects the drug fluorescence component, the fluorescence detection means 4 detects the autofluorescence component, and the respective outputs are added to add the fluorescence sum component You may ask for. In addition, the wavelength is separated into the autofluorescence component and the fluorescence sum component of the drug fluorescence component and the autofluorescence component, the autofluorescence component is detected by the fluorescence detection means 3, the fluorescence sum component is detected by the fluorescence detection means 4, and the fluorescence The drug fluorescence component may be obtained by subtracting the autofluorescence component from the sum component.
[0027]
Hereinafter, the operation of the fluorescence detection apparatus having the above configuration will be described. When the observation unit 10 is irradiated with the excitation light L1, the observation unit 10 emits fluorescence L3 having a spectrum shown in FIG. This fluorescence L3 is an autofluorescence component Ifλ due to in vivo dyes such as FAD and NADH.₂And the drug fluorescence component Ifλ by the fluorescent diagnostic agent accumulated in the lesion.₁It consists of. In general, autofluorescence component Ifλ₂Has a maximum peak around the wavelength of 500 nm and attenuates greatly at a wavelength of 600 nm or more. On the other hand, the drug fluorescence component Ifλ₁Has a maximum peak at a wavelength of 600 nm or more.
[0028]
Each wavelength component detected by the fluorescence detection means 3 and 4 is expressed as follows.
[0029]
Drug fluorescence component Ifλ₁Is
Ifλ₁= Kλ₁・ Iλ_ex・ ΗFλ₁・ N ・ ηD
Apparent autofluorescence component Ifλ₂Is
Ifλ₂= Kλ₂・ Iλ_ex・ ΗFλ₂・ N ・ ηD
Fluorescence sum component Ifλ₊Is
Ifλ₊= Ifλ₁+ Ifλ₂
The symbols used here have the following meanings unless otherwise specified. The same applies to the case of drug fluorescence detection.
[0030]
λ_ex: Excitation light wavelength
Iλ_ex: Intensity of excitation light in the living body observation part depending on the distance L from the excitation light source to the living body observation part, the power P of the excitation light limit, and the angle θ between the excitation light beam and the observation part, Iλ_ex= Iλ_ex (L, P, θ)
n: Apparent autofluorescent molecule concentration (There may be multiple types of autofluorescent molecules, but the term “apparently” is used here in the sense that it can be treated as if there is virtually one type of molecule. Is used.)
N: Drug fluorescent molecule concentration
kλ₁  : Excitation light wavelength λ_exAnd the constant depending on the drug fluorescent molecule
kλ₂  : Excitation light wavelength λ_exAnd constants depending on the apparent autofluorescent molecule
kλ₁₂ : Excitation light wavelength λ_exAnd constants depending on the apparent fluorescent molecules contributing to fluorescence in the entire wavelength range
ηFλ₁: Excitation light wavelength of drug fluorescent molecule λ_exFluorescence quantum yield for
ηFλ₂: Apparent autofluorescent molecule excitation light wavelength λ_exFluorescence quantum yield for
ηFλ₁₂: Apparent light wavelength λ of apparent fluorescent molecules that contribute to fluorescence in the entire wavelength range_exFluorescence quantum yield for
ηD: Fluorescence detection efficiency depending on the distance L ′ between the light emitting part and the condensing optical system, the aperture size D of the condensing system, and the efficiency ξ of the detector, ηD = ηD (L ′, ξ, D) (Strictly speaking, the detection efficiency for autofluorescence is different from the detection efficiency for drug fluorescence, but here they can be treated as being approximately equal.)
It is.
[0031]
Next, the drug fluorescence component Ifλ₁And the fluorescence sum component Ifλ₊Is divided by the dividing means 5. Drug fluorescence Ifλ₁And fluorescence sum Ifλ₊When dividing with
Ifλ₁ / Ifλ₊= (Kλ₁ ・ ΗFλ₁・ N) / (kλ₁ ・ ΗFλ₁・ N + kλ₂・ ΗFλ₂・ N)
Where (kλ₁ ・ ΗFλ₁) / (kλ₂・ ΗFλ₂) = C, N / n = X
Then,
Ifλ₁ / Ifλ₊= (C ・ X) / (C ・ X + 1)
Since C is a constant term, Ifλ₁/ Ifλ₊Is represented as the graph in Figure 3. That is, non-uniformity Iλ depending on the location of the excitation light illuminance_exWill be cancelled. The value of X represents the concentration of the drug fluorescent molecule normalized by the autofluorescent molecule concentration.₁/ Ifλ₊A large value means a lesion. Thus, the fluorescence sum component Ifλ₊And drug fluorescence component Ifλ₁It is possible to extract a lesion part specifically by performing a division operation between and. At this time, the fluorescent sum component Ifλ is used in the denominator.₊By using, the denominator can be increased and the occurrence of calculation errors associated with zero division can be suppressed. Therefore, for example, by using an imaging device as the fluorescence detection means 3 and 4, a fluorescence image with corrected fluorescence intensity can be displayed as a visible image on the display means 6.
[0032]
As the excitation light, the excitation peak wavelength λ of the fluorescent diagnostic agent_ex1Light in the near wavelength region and the excitation peak wavelength λ of the endogenous dye_ex2 When using light in the vicinity of the wavelength region, a fluorescence spectrum shown in FIG. 4 is obtained from the living body observation unit. here,
Ifλ₁ : Wavelength λ of fluorescence from living body observation part_ex1Contribution of drug excitation light to drug fluorescence
Ifλ₁': Λ of the fluorescence from the living body observation part_ex2Contribution of drug excitation light to drug fluorescence
Ifλ₂ : Wavelength λ of fluorescence from living body observation part_ex1Of the excitation light to the autofluorescence
Ifλ₂': Λ of the fluorescence from the living body observation part_ex2Of the excitation light to the autofluorescence
Iλ_ex1: Wavelength λ_ex1Excitation light intensity at the living body observation part
Iλ_ex2: Wavelength λ_ex2Excitation light intensity at the living body observation part
However, Iλ_ex1And Iλ_ex2Have the same light distribution and Iλ_ex2= M · Iλ_ex1Assume that m is an arbitrary constant.
[0033]
Similarly to the above, wavelength separation into a predetermined wavelength region is performed, and the fluorescence detection means 3 causes the drug fluorescence component Ifλ₁+ Ifλ₁′ And the fluorescence detection means 4 detects the fluorescence sum component Ifλ.₊= Ifλ₁+ Ifλ₁'+ Ifλ₂+ Ifλ₂'Is detected.
[0034]
Where Ifλ₁, Ifλ₁', Ifλ₂, Ifλ₂'
Ifλ₁ = K₁λ₁・ Iλ_ex1 ・ ΗFλ₁・ N ・ ηD
Ifλ₁'＝ k₁λ₁′ ・ Iλ_ex1・ ΗFλ₁′ ・ N ・ ηD
Ifλ₂= K₂λ₂・ Iλ_ex2・ ΗFλ₂・ N ・ ηD
Ifλ₂'＝ k₂λ₂′ ・ Iλ_ex2・ ΗFλ₂′ ・ N ・ ηD
It is expressed. here,
k₁λ₁: Excitation light wavelength λ_ex1And the constant depending on the drug fluorescent molecule
k₁λ₁': Excitation light wavelength λ_ex2And the constant depending on the drug fluorescent molecule
ηFλ₁  : Excitation light wavelength of drug fluorescent molecule λ_ex1Fluorescence quantum yield for
ηFλ₁': Excitation light wavelength λ of drug fluorescent molecule_ex2Fluorescence quantum yield for
k₂λ₂: Excitation light wavelength λ_ex1Constants depending on the autofluorescence molecule
k₂λ₂': Excitation light wavelength λ_ex2Constants depending on the autofluorescence molecule
ηFλ₂: Apparent autofluorescent molecule excitation light wavelength λ_ex1Fluorescence quantum yield for
ηFλ₂': Apparent autofluorescent molecule excitation light wavelength λ_ex2Fluorescence quantum yield for
It is.
[0035]
Next, the drug fluorescence component Ifλ₁+ Ifλ₁'And the fluorescence sum component Ifλ₊= Ifλ₁+ Ifλ₁‘+ Ifλ₂+ Ifλ₂When division with 'is performed by the dividing means 5,
(Ifλ₁+ Ifλ₁’) / (Ifλ₁+ Ifλ₁'+ Ifλ₂+ Ifλ₂′) ＝ C ・ X / (1 + C ・ X)
However,
C = (k₁λ₁・ ΗFλ₁+ K₁λ₁′ ・ M ・ ηFλ₁’) / (K₂λ₂・ ΗFλ₂+ K₂λ₂′ ・ M ・ ηFλ₂’)
X = N / n
And C is a constant term (Ifλ₁+ Ifλ₁’) / (Ifλ₁+ Ifλ₁‘+ Ifλ₂+ Ifλ₂′) Is expressed as in the graph of FIG. That is, non-uniformity due to the location of excitation light illuminance_ex1, Iλ_ex2Will be cancelled. The value of X represents the drug fluorescent molecule concentration normalized by the autofluorescent molecule concentration.₁+ Ifλ₁’) / (Ifλ₁+ Ifλ₁‘+ Ifλ₂+ Ifλ₂A large ') means a lesion.
[0036]
Therefore, even in this case, the fluorescence sum component Ifλ₊Based fluorescence image and drug fluorescence component Ifλ₁+ Ifλ₁By performing the inter-image division with the fluorescence image based on ', the fluorescence from the lesion can be specifically extracted as an image. Thus, the fluorescence sum component Ifλ₊And drug fluorescence component Ifλ₁+ Ifλ₁By performing a division operation with ′, it is possible to specifically extract a lesion. At this time, the fluorescent sum component Ifλ is used in the denominator.₊ By using, the denominator can be increased and the occurrence of calculation errors associated with zero division can be suppressed. Therefore, for example, by using an imaging device as the fluorescence detection means 3 and 4, a fluorescence image with corrected fluorescence intensity can be displayed as a visible image on the display means 6. In addition, as the excitation light, the excitation peak wavelength λ of the fluorescent diagnostic agent_ex1Light in the near wavelength region and excitation peak wavelength λ of living dye_ex2By using light in the near wavelength region, the fluorescence intensity can be sufficiently increased, and a good fluorescence image with a high SN ratio can be obtained.
[0037]
The above explanation is for the case of detection of drug fluorescence, and the case where it is applied to the division of the drug fluorescence component and the fluorescence sum component of the drug fluorescence component and the autofluorescence component has been described. The present invention can be similarly applied to a fluorescence detection apparatus that detects autofluorescence emitted from the observation unit (hereinafter referred to as “autofluorescence detection”). In this case, the living body observation part is irradiated with excitation light, and a fluorescent component in a relatively long wavelength region (for example, a red region component R. hereinafter referred to as a “long wavelength component”) among the autofluorescence generated by the living body dye. )) And a fluorescence sum component of a long wavelength component and a fluorescent component in a relatively short wavelength region (for example, a green region component G, hereinafter referred to as a “short wavelength component”). This case will be described in detail below.
[0038]
As in the case of the above-described drug fluorescence detection, the autofluorescence L3 generated from the in-vivo dye of the living body observation unit 10 is converted into a long wavelength component Ifλ by a dichroic mirror or an optical filter.₁And long wavelength component Ifλ₁And short wavelength component Ifλ₂Fluorescence sum component Ifλ₊The fluorescence detection means 3 detects a long wavelength component in the autofluorescence L3 generated from the living body dye of the living body observing unit 10, and the fluorescence detecting means 4 detects the self generated from the living body dye of the living body observing section 10. The fluorescence sum component in the fluorescence L3 is detected. Other configurations are the same as in the case of the above-described drug fluorescence detection. The means for detecting the long wavelength component and the means for detecting the fluorescence sum component are not limited to this configuration example, and the wavelength detection is performed by separating the wavelength into a predetermined wavelength region, and the detection result is subjected to operations such as addition and subtraction. It is possible to obtain a fluorescent component in a wavelength region that is finally required by performing the process. For example, the wavelength is separated into a long wavelength component and a short wavelength component, the long wavelength component is detected by the fluorescence detection means 3, the short wavelength component is detected by the fluorescence detection means 4, and the respective outputs are added to add the fluorescence sum component. You may ask for. Further, the wavelength is separated into a short wavelength component and a fluorescence sum component of the long wavelength component and the short wavelength component, the short wavelength component is detected by the fluorescence detection means 3, the fluorescence sum component is detected by the fluorescence detection means 4, and the fluorescence The long wavelength component may be obtained by subtracting the short wavelength component from the sum component.
[0039]
Hereinafter, the operation of the fluorescence detection apparatus having the above configuration will be described. When the observation unit 10 is irradiated with the excitation light L1, the observation unit 10 emits autofluorescence L3 having a spectrum shown in FIG. This autofluorescence L3 is presumed to be superimposed with fluorescence from various in vivo dyes such as FAD, collagen, fibronectin, porphyrin, etc. As shown in the fluorescence spectrum in FIG. And the size of the fluorescence spectrum is different and the shape is different, the autofluorescence L3 is generally large in the normal part, but the autofluorescence L3 is generally reduced in the lesion part, and particularly in this lesion part, the blue color ~ Compared with the degree of reduction of the green fluorescent component, the degree of reduction of the fluorescent component having a longer wavelength than that of red is small (however, the reason why the fluorescence spectrum differs between the lesioned part and the normal part has not been elucidated). That is, in the lesioned part and the normal part, the fluorescence component near red (long wavelength component) Ifλ₁And green fluorescent component (short wavelength component) Ifλ₂Ifλ obtained by division₁/ Ifλ₊ It can be determined that the part where the value of is large is a lesioned part, and the part where the value is small is a normal part. Each wavelength component is expressed as follows.
[0040]
Apparent long wavelength component Ifλ when irradiated with excitation light L1₁ Is
Ifλ₁ = Kλ₁・ Iλ_ex・ ΗFλ₁・ N ・ ηD
Apparent short wavelength component Ifλ when irradiated with excitation light L1₂ Is
Ifλ₂ = Kλ₂・ Iλ_ex・ ΗFλ₂・ N ・ ηD
Therefore, the fluorescence sum component Ifλ of the short wavelength component and the long wavelength component₊Is expressed as follows.
[0041]
Ifλ₊= (Kλ₁・ Iλ_ex・ ΗFλ₁・ N ・ ηD) + (kλ₂・ Iλ_ex・ ΗFλ₂・ N ・ ηD)
The symbols used here have the following meanings unless otherwise specified. The same applies to the case of autofluorescence detection.
[0042]
λ_ex: Excitation light wavelength
Iλ_ex: Excitation light intensity at the living body observation part, Iλ depending on the distance L from the excitation light source to the living body observation part, the power P of the excitation light source, and the angle θ between the excitation light beam and the observation part_ex= Iλ_ex (L, P, θ)
n: Apparent autofluorescent molecule concentration that contributes to fluorescence in the long wavelength region (although there may be multiple types of fluorescent molecules that contribute to autofluorescence, it can be treated as if there is virtually one type of molecule In this sense, the term “apparent” is used here, and so on.)
N: Apparent autofluorescent molecule concentration contributing to fluorescence in the short wavelength region
M: Apparent autofluorescent molecule concentration that contributes to fluorescence in all wavelengths
kλ₁  : Excitation light wavelength λ_exAnd constants depending on the apparent fluorescent molecules contributing to long-wavelength fluorescence
kλ₂  : Excitation light wavelength λ_exAnd constants depending on the apparent fluorescent molecules contributing to fluorescence in the short wavelength region
kλ₁₂  : Excitation light wavelength λ_exAnd constants depending on the apparent fluorescent molecules contributing to fluorescence in the entire wavelength range
ηFλ₁: Apparent light wavelength λ of apparent fluorescent molecules contributing to fluorescence in the long wavelength region_exFluorescence quantum yield for
ηFλ₂: Apparent light wavelength λ of apparent fluorescent molecules that contribute to fluorescence in the short wavelength region_exFluorescence quantum yield for
ηFλ₁₂: Apparent light wavelength λ of apparent fluorescent molecules that contribute to fluorescence in the entire wavelength range_exFluorescence quantum yield for
ηD: Fluorescence detection efficiency depending on the distance L ′ between the light emitting part and the light receiving system, the aperture size D of the light receiving system, and the efficiency ξ of the detector, ηD = ηD (L ′, ξ, D) ( Strictly speaking, although the detection efficiency for fluorescence in the short wavelength region is different from the detection efficiency for fluorescence in the long wavelength region, they can be treated as approximately equal here.
Next, the long wavelength fluorescent component Ifλ is divided by the dividing means 5.₁And the fluorescence sum component Ifλ₊(Ifλ₁+ Ifλ₂) Divide with. Division value Ifλ₁/ (Ifλ₁+ Ifλ₂) Is expressed as follows:
[0043]
Ifλ₁/ (Ifλ₁+ Ifλ₂) = (Kλ₁・ ΗFλ₁・ N) / (kλ₁・ ΗFλ₁・ N + kλ₂・ ΗFλ₂・ N)
By this division operation, the non-uniformity Iλ due to the location of the illumination intensity of the excitation light_exWill be cancelled. Therefore, it is applied to the division of the long wavelength component (for example, red region component R) of autofluorescence, and the short wavelength component (for example, green region component G) and the fluorescence sum component (G + R) of the long wavelength component. Even in the case, the fluorescent sum component Ifλ in the denominator₊By using, the denominator can be increased and the occurrence of calculation errors associated with zero division can be suppressed. Therefore, for example, by using an imaging device as the fluorescence detection means 3 and 4, a fluorescence image with corrected fluorescence intensity can be displayed as a visible image on the display means 6.
[0044]
The fluorescence detection apparatus according to the present invention can also be applied to the division of the fluorescence difference component and the fluorescence sum component. First, in the case of drug fluorescence detection, the fluorescence difference component (In−Ex) between the autofluorescence component In and the drug fluorescence component Ex, and the fluorescence sum component (Ex + In) of the autofluorescence component In and the drug fluorescence component Ex The case of applying to the division with.
[0045]
In the same manner as described above, the fluorescence L3 generated from the living body observation unit 10 is collected by the condensing optical system 2, and the autofluorescence component and the drug fluorescence component emitted from the living body observation unit 10 by a dichroic mirror, an optical filter, or the like. The wavelength difference is separated into the fluorescence difference component and the fluorescence sum component of the autofluorescence component and the drug fluorescence component, the fluorescence detection means 3 detects the fluorescence difference component, and the fluorescence detection means 4 detects the fluorescence sum component. Other configurations are the same as those described above. It should be noted that the wavelength ranges of “autofluorescent component” and “drug fluorescent component” included in the fluorescence difference component are not necessarily the same as each wavelength region of “autofluorescent component” and “drug fluorescent component” included in the fluorescence sum component. Need not be. Further, as in the case described above, the means for detecting the fluorescence difference component and the means for detecting the fluorescence sum component are not limited to this configuration example, and the detection is performed by separating the wavelength into a predetermined wavelength region. It goes without saying that the fluorescent component in the wavelength region that is finally required may be obtained by performing operations such as addition and subtraction on the result. Hereinafter, the operation of the fluorescence detection apparatus having the above configuration will be described in detail.
[0046]
Each wavelength component detected by the fluorescence detection means 3 and 4 is expressed as follows. As apparent from the above description, the fluorescence sum component Ifλ₊Is

On the other hand, fluorescence difference component Ifλ₋Is

Next, the fluorescence difference component Ifλ_-And the fluorescence sum component Ifλ₊ Is divided by the dividing means 5. Fluorescence difference component Ifλ_-And the fluorescence sum component Ifλ₊ When dividing with

It becomes. That is, even in this configuration, the non-uniformity Iλ depending on the location of the excitation light illuminance_exWill be cancelled. The value of X represents the drug fluorescent molecule concentration normalized by the autofluorescent molecule concentration._-/ Ifλ₊ A large value indicates that the drug fluorescence is weak, indicating that it is a normal site, and conversely, Ifλ_-/ Ifλ₊ When becomes small, it indicates that the drug fluorescence is strong, which means that it is a lesioned part. Thus, the fluorescence difference component Ifλ_-And the fluorescence sum component Ifλ₊ It is also possible to specifically extract a lesioned part by performing a division operation between and. At this time, the fluorescent sum component Ifλ is used in the denominator.₊ By using, the denominator can be increased and the occurrence of calculation errors associated with zero division can be suppressed.
[0047]
Although the above description has been given of the case of drug fluorescence detection, it is needless to say that the same applies to the case of autofluorescence detection. In this case, the “fluorescence difference component” in the above description is a fluorescence difference component (G−R) between a short wavelength component (for example, a green region component G) and a long wavelength component (for example, a red region component R), The “fluorescence sum component” is considered as a “fluorescence sum component (G + R) of a short wavelength component (eg, green region component G) and a long wavelength component (eg, red region component R)”.
[0048]
In the above description, the case where the division with the fluorescence sum component is performed has been described. However, the case where the division with the fluorescence component of the entire region excited by the excitation light (the total fluorescence component) can be similarly applied. It is. This case will be described in detail below. First, in the case of autofluorescence detection, a fluorescence difference component (GR) between a short wavelength component (for example, a green region component G) and a long wavelength component (for example, a red region component R), and a total fluorescence component The case of applying to the division with.
[0049]
Similarly to the case of the above-described fluorescence sum component, the fluorescence L3 generated from the living body observation unit 10 is collected by the condensing optical system 2, and the short wavelength component and the long wavelength emitted from the living body observation unit 10 by a dichroic mirror, an optical filter, or the like. The wavelength difference is separated into the fluorescence difference component with respect to the wavelength component and the total fluorescence component from the short wavelength component to the long wavelength component, the fluorescence detection means 3 detects the fluorescence difference component, and the fluorescence detection means 4 detects the total fluorescence component. Other configurations are the same as those described above. As in the case described above, the means for detecting the fluorescence difference component and the means for detecting the total fluorescence component are not limited to this configuration example, and the detection is performed by separating the wavelength into a predetermined wavelength region. It goes without saying that the fluorescent component in the wavelength region that is finally required may be obtained by performing operations such as addition and subtraction on the result. In particular, as a means for detecting the total fluorescent component, the wavelength separation characteristics of the short wavelength component and the long wavelength component are devised (for example, the cutoff characteristic of the short wavelength component on the long wavelength side and the cutoff characteristic of the long wavelength component on the short wavelength side) And so on), the wavelength can be separated into a short wavelength component and a long wavelength component, and the result is added to obtain a fluorescence sum component, so that this fluorescence sum component can be considered as a total fluorescence component. Is possible. In other words, in this case, the configuration for performing the division with the fluorescence sum component described above can function as the configuration for performing the division with all the fluorescent components as it is. The same applies hereinafter.
[0050]
Hereinafter, the operation of the fluorescence detection apparatus having the above configuration will be described in detail. Each wavelength component detected by the fluorescence detection means 3 and 4 is expressed as follows. As apparent from the above description, the fluorescence difference component Ifλ₋Is

On the other hand, the total fluorescence component Ifλ from the short wavelength region to the long wavelength region₁₂Is
Ifλ₁₂= Kλ₁₂・ Iλ_ex・ ΗFλ₁₂・ M ・ ηD
Next, the fluorescence difference component Ifλ_-And total fluorescence component Ifλ₁₂Is divided by the dividing means 5. Fluorescence difference component Ifλ_-And the fluorescence sum component Ifλ₁₂ When dividing with

It becomes. However, C₁ And C₂ Is a constant.
[0051]
That is, even in this configuration, the non-uniformity Iλ depending on the location of the excitation light illuminance_exWill be cancelled. Where Ifλ_-/ Ifλ₁₂A large value indicates that the fluorescence in the short wavelength region is strong, indicating that it is a normal site, and conversely, Ifλ_-/ Ifλ₁₂When becomes small, it indicates that the fluorescence in the short wavelength region is weak, which means that it is a lesioned part. Thus, the fluorescence difference component Ifλ_-And total fluorescent component Ifλ₁₂It is also possible to specifically extract a lesioned part by performing a division operation between and. At this time, the total fluorescent component Ifλ in the denominator₁₂By using, the denominator can be increased and the occurrence of calculation errors associated with zero division can be suppressed.
[0052]
The above description is the case of autofluorescence detection, and the fluorescence difference component (GR) between the short wavelength component (for example, the green region component G) and the long wavelength component (for example, the red region component R), and the total fluorescence. Although the case of applying to the division with the component has been described, it is needless to say that the same can be applied to the case of dividing the long wavelength component (for example, the red region component R) and the total fluorescent component. In this case, the “fluorescence difference component” in the above description is considered as a “long wavelength component”.
[0053]
Further, the above description is for the case of autofluorescence detection, but it goes without saying that the same can be applied to the case of drug fluorescence detection. In this case, the “division of the fluorescence difference component between the short wavelength component and the long wavelength component and the total fluorescence component” in the above description is “the fluorescence difference component (In−Ex) between the autofluorescence component In and the drug fluorescence component Ex”. “Division with all fluorescence components” and “division between long wavelength components and all fluorescence components” are considered as “division between drug fluorescence component Ex and all fluorescence components”.
[0054]
Next, an example of a specific embodiment to which the fluorescence detection apparatus according to the present invention is applied will be described. FIG. 6 is a schematic configuration diagram of an endoscope apparatus to which the fluorescence detection apparatus according to the present invention is applied. This endoscope is emitted by irradiating a living body observation part, into which a fluorescent diagnostic agent has been previously injected, with excitation light. Fluorescence is detected, and a red fluorescent component is divided from a blue fluorescent component, a green fluorescent component, and a fluorescent sum component of a red fluorescent component.
[0055]
The endoscope apparatus according to the third embodiment of the present invention includes an endoscope 100 inserted into a site suspected of being a patient's lesion, a light source that emits normal observation white light and fluorescence image observation excitation light. The illumination device 110 includes a high-sensitivity camera unit 300 as a fluorescence detection unit that detects reflected light from the living body irradiation site of the white light during normal observation and fluorescence from the living body irradiation site of the excitation light during fluorescence image observation. The image processing device 310 performs image processing of the detected reflected light image or fluorescence image, and the display 160 displays the image information processed by the image processing device 310 as a visible image.
[0056]
The endoscope 100 includes a light guide 106 and an image fiber 104 that extend to the distal end of the endoscope insertion portion 101 inside the endoscope insertion portion 101. The distal end portion of the endoscope insertion portion 101 includes an illumination lens 102 and an objective lens 103, respectively. One end of the light guide 106 reaches the interior of the illumination device 110 through the connection portion 107 that connects the operation device 105 from the illumination device 110. One end of the image fiber 104 extends into the operation unit 105 and is in contact with an eyepiece unit 108 having an eyepiece lens 109.
[0057]
The illumination device 110 sets a xenon lamp 118 that emits white light L2 for normal image observation, a mercury lamp 111 that emits excitation light L1 for fluorescence observation, and a transmission wavelength of the excitation light L1 emitted from the mercury lamp 111 The optical filter 112 includes a switching mirror 115 driven by a driver 116 for switching between the white light L2 and the excitation light L1 between normal observation and fluorescence observation.
[0058]
The high-sensitivity camera unit 300 is an excitation light sharp-cut filter 302 that cuts off the reflected light and the excitation light component of the fluorescence L3, and an imaging unit that forms an image of the reflected light and the fluorescence L3 that has passed through the filter 302. The cooling CCD camera 303 is provided with a color mosaic filter 304 whose schematic view is shown in FIG. The color mosaic filter 304 includes fine filters R, G, and B that separate fluorescence into wavelength regions of R, G, and B colors, and the optical transmission characteristics of each filter are as shown in FIG.
[0059]
The image processing device 310 includes an A / D conversion circuit 311 for digitizing the video signal obtained by the cooled CCD camera 303, an R image memory 314 for storing each digitized RGB image signal, a G image memory 313, B An image memory 312, an addition memory 315 that stores an addition signal that reflects a fluorescence sum component obtained by adding the outputs of the image memories, and a division process that divides the output of the R image memory 314 and the output of the addition memory 315. A division memory 316 for storing the result, a video signal generation circuit 317 for performing image processing for displaying the division image signal stored in the division memory 316 as a visible image on the display 160, an illumination device 110, and an optical path switching unit 120. It comprises a timing controller 319 that sends signals to drivers 116 and 123 that drive the switching mirrors 115 and 121, and a video processor 318 that controls the timing controller 319.
[0060]
The operation of the endoscope apparatus having the above configuration to which the fluorescence detection apparatus according to the present invention is applied will be described below. First, the operation of the endoscope apparatus during normal image observation will be described.
[0061]
During normal observation, the switching mirror 115 in the illumination device 110 is driven by the driver 116 based on the signal from the timing controller 158 and moves to the position of the broken line so as not to obstruct the progress of the white light L2. The white light L2 output from the xenon lamp 118 goes to the switching mirror 115 via the lens 117. The white light L2 is input to the light guide 106 by the lens 114, guided to the distal end portion of the endoscope, and then irradiated from the illumination lens 102 to the observation unit 10 including the lesioned part 11.
[0062]
The reflected light of the white light L2 irradiated on the living body is collected by the objective lens 103 and travels to the high sensitivity camera unit 300 through the image fiber 104 and the eyepiece 109 provided in the eyepiece 108. The reflected light of the white light L 2 that has passed through the eyepiece lens 109 passes through the lens 301 and the excitation light sharp cut filter 302 and forms an image on the cooled CCD camera 303. Since the color mosaic filter 304 is mounted on the detection surface of the cooled CCD camera 303, the light transmitted through the color mosaic filter 304 is separated into wavelength regions of R, G, and B colors. The video signal from the cooled CCD camera 303 is input to the A / D conversion circuit 311, digitized for each RGB video signal component, and then stored in the R image memory 314, G image memory 313, and B image memory 312, respectively. Is done. The normal image signals stored in the R image memory 314, the G image memory 313, and the B image memory 312 are color matrix processed and encoded after the DA conversion by the video signal generation circuit 317, and input to the display 160 as an NTSC signal. It is displayed on the display 160 as a visible image.
[0063]
Next, the action at the time of fluorescent image observation will be described. Here, as a fluorescent diagnostic agent, λ_em= The case where 5-ALA emitting fluorescence around 635 nm is used will be described. The fluorescent diagnostic agent 5-ALA is administered in advance to the irradiated part of the living body.
[0064]
The switching mirror 115 is driven by the driver 116 based on a signal from the timing controller 158 to move to the position of the solid line so as to block the passage of the white light L2 and reflect the excitation light L1. The excitation light L1 output from the mercury lamp 111 passes through the optical filter 112 and the lens 113 and travels to the switching mirror 115. The excitation light L1 reflected by the switching mirror 115 is input to the light guide 106 by the lens 114, guided to the distal end portion of the endoscope, and then irradiated to the observation unit 10 including the lesioned part 11 from the illumination lens 102. . The optical filter 112 has a transmission characteristic as shown in FIG. 9, and the excitation light L1 emitted from the mercury lamp 111 transmitted through the optical filter 112 has an emission line spectrum with a wavelength of 405 nm.
[0065]
The fluorescence L3 from the living body observation unit 10 generated by the irradiation of the excitation light is collected by the objective lens 103, passes through the image fiber 104 and the eyepiece lens 109, passes through the excitation light sharp cut filter 302, and the excitation light component is generated. After the removal, the color mosaic filter 304 mounted on the detection surface of the cooled CCD camera 303 is separated into wavelength regions of R, G, and B colors and formed into an image on the cooled CCD camera 303. Since the fluorescence intensity is weaker than that of the normal observation light, the imaging rate of the cooled CCD camera 303 is sufficiently slower than that of the normal image observation during the fluorescence image observation. The fluorescent video signal from the cooled CCD camera 303 is input to the A / D conversion circuit 311 and digitized for each of the R image, G image, and B image, and then the R image memory 314, G image memory 313, and B image, respectively. Stored in memory 312. After each video signal reflecting the RGB fluorescent image is acquired, the addition memory 315 performs the addition processing of the outputs of the R image memory 314, the G image memory 313, and the B image memory 312 and the addition result is a fluorescence sum component. Is stored in the addition memory 315 as an addition signal reflecting the above. The fluorescence from the living body mainly reflects the drug fluorescence in the R video signal, and the BG video signal mainly reflects the autofluorescence. Therefore, the addition result represents the sum of the autofluorescence and the drug fluorescence.
[0066]
Next, the division memory 316 performs division processing between the output of the R image memory 314 and the output of the addition memory 315, and the division result is stored in the division memory 316. The divided image signal stored in the division memory 316 is encoded by the video signal generation circuit 317 after DA conversion and displayed on the display 160 as a visible image. In addition, by providing a memory for storing the normal image separately from the RGB memory, the divided image and the normal image can be displayed in an overlay manner.
[0067]
For the mercury lamp 111, an optical filter having a transmission characteristic different from that of the optical filter 112 can be used. For example, as shown in FIG. 10, the 405 nm and 365 nm emission lines are selectively transmitted. It is also possible to use an optical filter capable of 405nm is the wavelength λ that can excite fluorescent diagnostic agents with high efficiency_ex1365nm is the wavelength λ that can excite autofluorescent molecules with high efficiency._ex2Therefore, it is desirable to use these two types of light together for improving the SN ratio. The same applies to the case of drug fluorescence detection.
[0068]
In this configuration, since the autofluorescence has a strong G region, when the sum of the autofluorescence component and the drug fluorescence component is obtained, an addition process of the output of the G image memory 313 and the output of the R image memory 314 is performed. It may be replaced with.
[0069]
Further, the wavelength separation characteristic of the color mosaic filter 304 in this configuration is shown in FIG. 8, and obtaining the fluorescence sum component can be considered to be substantially equivalent to obtaining all the fluorescence components. In this case, by changing the wavelength separation characteristics of the color mosaic filter 304 (for example, preventing the cut-off characteristics of each color from overlapping), the function is performed to divide the fluorescence sum components that are not equivalent to the total fluorescence components It can also be made.
[0070]
Further, in this endoscope apparatus, a color mosaic filter 304 is attached to the fluorescence detection surface of the high-sensitivity camera unit 300 that is a fluorescence detection means, and the fluorescence is separated into a desired wavelength region by the color mosaic filter 304. Therefore, the configuration of the high sensitivity camera unit 300 can be simplified.
[0071]
For this reason, it is possible to easily arrange a CCD camera having the color mosaic filter 304 attached to the distal end portion of the endoscope, that is, to be applied as an electronic endoscope having an imaging device at the distal end portion of the endoscope. Can do.
[0072]
Furthermore, the sharp cut filter used in the apparatus according to the above embodiment can be appropriately changed according to the desired excitation light wavelength.
[0073]
In addition, the description of the above embodiment is for the case where drug fluorescence detection is performed, but it goes without saying that it can be applied to an autofluorescence diagnostic imaging apparatus that performs autofluorescence detection. It can be applied almost as it is. However, as the excitation light, light having a wavelength in the vicinity of the excitation peak wavelength of the living dye may be used.
[0074]
In addition, the description of the specific embodiment above is for the case of dividing the drug fluorescence component or the long wavelength component (for example, the red component R), but the fluorescence difference component ((In-Ex) or (GR). It can also be applied to the case of dividing)).
[Brief description of the drawings]
FIG. 1 is a basic configuration diagram of a fluorescence detection apparatus according to the present invention.
Fig. 2 Excitation wavelength λ_exAnd autofluorescence Ifλ₂And the drug fluorescence Ifλ₁Principle explanatory diagram showing the relationship
[Figure 3] Drug fluorescence Ifλ₁And total fluorescence Ifλ Division with Ifλ₁Illustration of the principle that shows the relationship between / Ifλ and the variable N / n = X that standardizes the concentration of the fluorescent drug molecule by the autofluorescent molecule concentration
FIG. 4 Excitation wavelength λ_ex1And excitation wavelength λ_ex2Autofluorescence Ifλ₂, Ifλ₂'And drug fluorescence Ifλ₁, Ifλ₁Illustration of the principle showing the relationship with
FIG. 5: Drug fluorescence Ifλ₁Divides the total fluorescence Ifλ by Ifλ₁/ If = (Ifλ₁+ Ifλ₁') / (Ifλ₁+ Ifλ₁'+ Ifλ₂+ Ifλ₂') And the principle explanatory diagram showing the relationship between the autofluorescent molecule concentration and the variable N / n = X that standardizes the drug fluorescent molecule concentration
FIG. 6 is a schematic configuration diagram of an endoscope apparatus which is a specific embodiment to which the fluorescence detection apparatus according to the present invention is applied.
FIG. 7 is an explanatory diagram showing a color mosaic filter used in a high-sensitivity camera used in the endoscope apparatus according to the embodiment.
FIG. 8 is a light transmission characteristic diagram of the color mosaic filter.
FIG. 9 is an explanatory diagram showing an excitation light spectrum of the excitation light source according to the embodiment.
FIG. 10 is an explanatory diagram showing another aspect of the excitation light spectrum of the excitation light source of the embodiment.
FIG. 11 is an explanatory diagram showing a fluorescence spectrum of autofluorescence.
[Explanation of symbols]
1 Excitation light irradiation means
2 Condensing optical system
3 Fluorescence detection means
4 Fluorescence detection means
5 Division means
6 Display means
L1 excitation light
L3 fluorescence
100 endoscope
104 Image fiber
106 Light guide
110 Lighting equipment
111 Mercury lamp
115 Switching mirror
118 Xenon lamp
160 display
300 High sensitivity camera unit
303 cooled CCD camera
304 color mosaic filter
310 Image processor
311 A / D converter circuit
316 division image memory
317 Video signal generator
318 video processor
319 Timing controller

Claims (4)

Excitation light irradiating means for irradiating excitation light in the excitation wavelength region of the fluorescent diagnostic agent and the in-vivo dye emitting fluorescence with respect to the observation part of the living body into which the fluorescent diagnostic agent emitting fluorescence is previously injected,
The total fluorescence component including the wavelength region of drug fluorescence emitted from the fluorescent diagnostic agent and the wavelength region of autofluorescence emitted from the living dye in the observation unit, or the wavelength region of drug fluorescence emitted from the fluorescent diagnostic agent Any one of the fluorescent sum components of the fluorescent component in a part of the wavelength region and the fluorescent component in the part of the wavelength region of the autofluorescent wavelength region emitted from the living body dye, and within the wavelength region of the drug fluorescence A partial drug fluorescent component that is a partial wavelength region of the fluorescent substance, or a fluorescent component of a partial wavelength region of the wavelength range of the fluorescent agent fluorescence, and a fluorescent component of a partial wavelength region of the wavelength range of the autofluorescence Fluorescence detection means for extracting any one of the fluorescence difference components;
Dividing means for dividing either the total fluorescence component or the fluorescence sum component extracted by the fluorescence detection means and the partial drug fluorescence component or the fluorescence difference component;
The fluorescence detection means includes a color mosaic filter that color-separates fluorescence emitted from the observation unit into a plurality of fluorescence components, and an imaging means that two-dimensionally detects fluorescence transmitted through the color mosaic filter. Extracting either the total fluorescence component or the fluorescence sum component and the partial drug fluorescence component or the fluorescence difference component from the plurality of fluorescence components detected by the imaging means after being color-separated by a mosaic filter And
The fluorescence detection apparatus, wherein the color mosaic filter is mounted on a fluorescence detection surface of the imaging means. An excitation light irradiation means for irradiating the observation part of the living body with the excitation light in the excitation wavelength region of the indigenous dye emitting fluorescence;
Of the autofluorescent component emitted from the living body dye of the observation unit, all of the autofluorescence component in the visible region including a relatively short wavelength region and a relatively long wavelength region, or emitted from the living body dye of the observation unit Any of the fluorescent sum components of the fluorescent component in a predetermined wavelength region within a relatively short wavelength region of the autofluorescent component and the fluorescent component in a predetermined wavelength region within a relatively long wavelength region of the autofluorescence A partial fluorescent component that is a part of a relatively long wavelength region of the autofluorescent component, or a partial wavelength region of a relatively short wavelength region of the autofluorescent component A fluorescence detection means for extracting any one of the fluorescence difference components between the fluorescence component and the fluorescence component of a part of the wavelength region within a relatively long wavelength region of the autofluorescence component;
Dividing means for performing division between either the total autofluorescence component or the fluorescence sum component extracted by the fluorescence detection means and the partial fluorescence component or the fluorescence difference component;
The fluorescence detection means includes a color mosaic filter that color-separates fluorescence emitted from the observation unit into a plurality of fluorescence components, and an imaging means that two-dimensionally detects fluorescence transmitted through the color mosaic filter. Extracting either the total autofluorescence component or the fluorescence sum component and the partial fluorescence component or the fluorescence difference component from the plurality of fluorescence components detected by the imaging means after being color-separated by a mosaic filter And
The fluorescence detection apparatus, wherein the color mosaic filter is mounted on a fluorescence detection surface of the imaging means.   The color mosaic filter is RGB The fluorescence detection apparatus according to claim 1, wherein the fluorescence detection apparatus is a mosaic filter.   Incorporated in an electronic endoscope having an insertion portion,
The fluorescence detection apparatus according to any one of claims 1 to 3, wherein the imaging unit is disposed at a distal end portion of the insertion portion.

Images