JP2000000231A5 - - Google Patents

Description

【００２２】
【数２】

【００２３】
このように、本願発明に係る体液測定装置によれば、使い捨て用として提供される装着体を本体に装着した上で、この装着体の皮膚当接面を患者の指先や耳たぶに押し当てた状態を保持しつつ、あたかも従来のランセットを扱うようにして穿刺体を突出させるという操作をするだけで、それ以上の操作、あるいは動作を要することなく、血糖値等の体液測定を適正に行うことができる。また、測定に必要な検体量が少なくてすむので、患者の負担が軽減される。
【００２４】
本願発明のその他の特徴および利点は、図面を参照して以下に行う詳細な説明から、明らかとなろう。
【００２５】
【発明の実施の形態】
以下、本願発明の好ましい実施の形態を図面を参照しつつ、説明する。図１は、本願発明に係る体液測定装置の全体外観図、図２は、穿刺体が退避した状態における装着体の詳細を示す拡大縦断面図であり図４のII−II線に沿う断面に相当する図、図３は、穿刺体が進出した状態における装着体の詳細を示す拡大縦断面図、図４は、装着体の底面図、図５は、センサを外した状態での装着体の底面図である。
【００２６】
図１ないし図３に示されるように、本願発明に係る体液測定装置10は、本体20と装着体30とを組み合わせて使用される。本体20は、その上面にスイッチボタン類、ＬＣＤ表示器22などが配置されている。この本体20の前部には筒状部21が延出形成されており、その先端部には、後に詳しく説明するキャップ状の装着体30が装着されている。また、この本体20の内部には、装着体30が備える穿刺体31を前進駆動するための駆動機構（23，32）、および、マイクロコンピュータ等の回路等が内蔵される。図１において符号23は、上記駆動機構の一部を構成し、使用者が手動によって押圧するための押圧部を示している。
【００２７】
図２ないし図５に装着体30の一例の詳細を示す。この装着体30は、円筒部34と、この円筒部34の先端を塞ぐように位置する底壁部35とを備える大略キャップ状をしており、その主要部分は樹脂成形によって作製される。円筒部34の内径は、本体20の前部筒状部24の外径と対応させられており、この前部筒状部24に被せるようにして簡便に装着することができる。底壁部35の外面は、使用者の皮膚に当接する皮膚当接面35ａとして機能させられる。
【００２８】
このキャップ状の装着体30の底壁部35には、穿刺体31と、バイオセンサ36とが一体に組み込まれる。底壁部35には、円筒壁35ｂと底壁35ｃとを有する円筒状の陥没部35Ａがこの装着体30の中心位置に形成され、この陥没部35Ａの底壁35ｃには、中心孔35ｄが開けられている。
【００２９】
一方、穿刺体31は、上記中心孔35ｄにスライド可能に嵌合するガイド軸部31ａとこのガイド軸部31ａの一端に一体形成されたフランジ部31ｂとを有する樹脂製のガイド体31Ａに金属製の穿刺針31ｃを一体にインサートした形態をもっており、フランジ部31ｂと後述する板状バイオセンサ36の上面との間に介装された弾性体37により、常時図２に示す退避位置、すなわち、フランジ部31ｂが陥没部35Ａの底壁35ｃに当接する位置に向けて付勢されている。この退避位置において、ガイド軸部31ａの後端は底壁35ｃの内側に突出した状態となり、穿刺針31ｃは、後述する板状バイオセンサ36の裏側に退避した状態となる。上記のように穿刺体31を退避位置に向けて付勢する弾性体37の態様としては、図２および図３に示されるように金属あるいは樹脂でできた圧縮コイルバネを用いるほか、発泡ウレタン等の形態とすることができる。このように弾性体37を発泡ウレタンの形態とし、穿刺体31が退避位置をとるとき穿刺針31ｃがこの発泡ウレタンの内部に埋没するようにしておくと、この穿刺針が外物に触れる機会を少なくすることができるので、衛生的である。また、上記弾性体37は、樹脂製のガイド体31Ａと一体成形された板状バネの形態とすることができる。
【００３０】
装着体30の底壁部35にはまた、上記穿刺体31が収容された陥没部35Ａを覆うようにして、板状バイオセンサ36が貼着される。このバイオセンサ36は、図６ないし図８に示したように穿刺体31の穿刺針31ｃが通過しうる貫通穴36ａと、この貫通穴36ａと連通して厚みのなかを底壁部35と平行に延びる体液通路36bを備え、この体液通路36bの内壁に反応部36ｋが形成された構成を備えている。
【００３１】
より具体的には、このバイオセンサ36は、上面に作用極36ｃおよび対極36ｄが膜形成された絶縁ベース板36Ａと、作用極36ｃおよび対極36ｄの一部を露出させる溝36ｅを形成するように絶縁ベース板36Ａ上に積層された板状スペーサ36Ｂ，36Ｂと、この板状スペーサ36Ｂ，36Ｂにさらに積層された板状カバー36Ｃとを備えている。以下、この板状バイオセンサ36の作製工程を説明する。
【００３２】
図９に示すように、たとえば０．２ｍｍの厚みをもつ樹脂製絶縁シートからなる平面視長矩形状のベース板36Ａが準備される。このベース板36Ａには、あらかじめたとえば１．５ｍｍ径の貫通穴361aが形成されている。このベース板36Ａの上面には、グラファイトインクを用いたスクリーン印刷の手法により、作用極36ｃと対極36ｄとが膜状に形成される。作用極36ｃは、端子部となるべき端部領域36ｆ（作用極36ｃに斜線のみを施した領域）から細状の突出部36ｇが延出形成された平面形態をもち、一方、対極36ｄは、端子部となるべき端部領域36ｈ（対極36ｄに斜線のみを施した領域）から上記作用極36ｃ側の突出部36ｇを両側から挟むように二股状に延びる突出部36ｉ，36ｉをもつ平面形態をもっている。貫通穴361aは、対極36ｄの一方の突出部36ｉと近接して位置している。なお、上記作用極36ｃおよび対極36ｄは、金や白金などの貴金属を蒸着するとともにエッチング処理して所定のパターンを作ることによって形成することもできる。
【００３３】
次に、作用極36ｃおよび対極36ｄの各突出部36ｇ，36ｉ，36ｉが縦方向に並ぶ帯状領域と、作用極36ｃおよび対極36ｄの各端部領域36ｆ，36ｈを残してレジスト層36ｊ（実線と一点鎖線で斜線を施した領域）を印刷形成する。
【００３４】
続いて、上記レジスト層36ｊに重ねるようにして、レジスト層36ｊと同等の平面形状を有するスペーサ板36Ｂ，36Ｂを配置する。このスペーサ板36Ｂとしては、たとえば厚み０．２ｍｍの樹脂製の板が採用され、表裏面に粘着剤層を設けた両面テープ態様のものが使用される。これにより、スペーサ板36Ｂ，36Ｂで挟まれる凹溝36ｅが形成され（図８参照）、かつこの凹溝36ｅの底部の帯状の領域に上記作用極36ｃと対極36ｄの各突出部36ｇ，36ｉ，36ｉが並んで露出する格好となる。なお、上記凹溝36ｅの幅は、たとえば１．５ｍｍ、長さはたとえば３ｍｍに設定される。
【００３５】
次に、上記凹溝36ｅの底部の帯状の領域に、図８に良く表れているような反応試薬層36ｋを形成する。血糖値測定用のセンサとして構成する場合、この反応試薬は、酸化酵素であるグルコースオキシターゼおよびメディエータとしてのフェリシアン化カリウムを含むものが採用される。反応試薬層36ｋはたとえば分注法により形成される。
【００３６】
次に、図９に示したように各スペーサ板36Ｂ，36Ｂに重ねるようにして、上記ベース板36Ａの貫通孔361aと対応する貫通孔362bを有する平面視矩形状のカバー板36Ｃを重ね合わせてこのバイオセンサ36が完成する。すなわち、図６ないし図８に表れているように、上記ベース板36Ａとスペーサ板36Ｂ，36Ｂとで形成された凹溝36ｅをカバー板36Ｃで塞ぐことによって縦方向に延びる断面横長矩形状の体液通路36ｂが形成され、かつ、この体液通路36ｂの内面に、作用極36ｃおよび対極36ｄに接触する試薬層36ｋ（反応部）が形成され、かつ、この体液通路36ｂはこの板状バイオセンサ36の貫通穴36ａに連通させられることとなる。また、体液通路36ｂにおける上記貫通穴36aの位置と反対側は、開放させられており、後述するように貫通穴36ａを介してこの体液通路36ｂないし反応部36ｋに毛管現象によって体液（血液）が導入されるのを促す。この体液通路36ｂの容積は、前述した凹溝36ｅの幅、長さ、およびスペーサ板36Ｂ，36Ｂの厚み寸法から、１．５ｍｍ×３ｍｍ×０．２ｍｍ＝０．９μｌとなるが、試薬層36ｋの固形分体積約０．２μｌを差し引くと、この体液通路36ｂの実質容積は約０．7 μｌというきわめて小さなものとなる。
【００３７】
上記のように形成された板状バイオセンサ36は、図２に良く表れているように装着体30の底壁部35に、穿刺針31ｃの位置とバイオセンサ36の貫通穴36ａの位置とが一致するようにして貼着される。なお、図４および図５に表れているように、装着体30の底壁部35には、バイオセンサ36のベース板36Ａの両端部に露出する作用極36ｃおよび対極36ｄ用の端子部36ｆ，36ｈと対応する丸穴362c，362dが形成されている。この丸穴362c，362dは、装着体30を本体20に装着したときに、本体20側のコネクタピン25ａ，25ａの先端を上記端子部36ｆ，36ｈに接触させるためのものである。装着体30の底壁部35にはまた、バイオセンサ貼着領域を挟むようにして弓形の開口36ｍ，36ｍが形成されている。この開口36ｍは、装着体30の底壁部35を皮膚当接面35ａとして皮膚に当接させた状態において、皮膚に負圧を作用させるためのものである。
【００３８】
一方、本体20の筒状部21には、コネクタピン25ａ，25ａの先端がこの筒状部21の前面に弾性的に突出するようにして、一対のピンコネクタ25，25が組み込まれている。このピンコネクタ25，25は、図１０に示したように電子回路33に接続されている。この電子回路33は、マイクロコンピュータなどで構成され、後述するようにバイオセンサ36内で生じる酵素反応および電気化学反応によって生じる作用電流から検量線を用いて血糖値等の被検知物質の測定値を決定するとともに、これを本体20の表面に配した表示器22に表示する機能をもたせてある。さらに、本体20には、図２および図３に示したように上記押圧部23によって押圧駆動される押圧ロッド32がその軸線方向（図中に矢印で示した方向）に移動可能であり、かつバネによって常時後方側に付勢されながら組み込まれて駆動機構23，32が構成されている。なお、駆動機構23，32としては、これに限らず、軸方向移動可能であってしかも軸方向の中立位置に弾性復帰するように押圧ロッド32を設け、この押圧ロッド32を後方に引き絞ってラッチ保持し、ラッチ解除ボタンを押すことでこの押圧ロッド32を勢い良く前方発射させ、この押圧ロッド32が穿刺体31のガイド軸部31ａの後端を勢いよく打ちつけ、これにともなって穿刺針31ｃが瞬間的に皮膚当接面35ａから突出するように構成することも可能である。また、図示しない吸引シリンダ機構を本体20に内蔵させることにより、筒状部21の先端に負圧を作用させることができるようにすることもできる。また、装着体30を本体20に装着したときにバイオセンサ36の端子部と導通接触するべく本体20に設ける端子は、前述したように常時ピンが弾性的に突出するピンコネクタの形態とするほか、たとえば、装着体30の本体20への装着と連動して、装着体30が装着されていないときには端子ピンが本体内に退動しており、装着体30が装着されると端子ピンが本体から突出してバイオセンサの端子部との適切な導通接触が図られるように構成することも可能である。
【００３９】
次に、上記構成を備える体液測定装置10の使用方法ないし動作を図１ないし図４を参照しつつ説明する。
【００４０】
装着体30は、使い捨て消耗品として提供され、体液測定装置10の使用にあたって使用者はこの装着体30を本体20の筒状部21に装着する（図１参照）。上記実施形態において装着体30はキャップ状をしているので、このような装着作業は容易に行える。装着体30が装着されると、図２に表れているように本体側のコネクタピン25ａ，25ａの先端が装着体30の底壁部35の丸穴362c，362dを介してバイオセンサ36のベース板36Ａ両端上面に配置された端子部36ｆ，36ｈに自動的に接触する。
【００４１】
装着体30の底壁部35の表面、すなわち皮膚当接面35ａを患者の皮膚の適当な部位、たとえば指先や耳たぶに押し当てた状態で、押圧部23を押下する。そうすると、本体20の内部の押圧ロッド32の先端が穿刺体31のガイド軸部31ａの後端部を押し、押圧ロッド32が装着体30の陥没部35Ａの裏側に当接するまでのストロークをもって穿刺体31を弾性体37の弾力に抗して前方に押し出す。このとき、穿刺体31の穿刺針31ｃは、バイオセンサ36の貫通孔36ａをとおってバイオセンサ36の下面、すなわち、皮膚当接面35ａから所定長さ突出する（図３の状態）。押圧部23への押圧を解除すると、押圧ロッド32はバネの弾力によって元の位置まで復帰動し、また、穿刺体31もまた弾性体37の弾力によって穿刺針31ｃが皮膚当接面35ａから没入する退避位置まで復帰する（図２の状態）。
【００４２】
皮膚当接面35ａからの穿刺針31ｃの突出により、皮膚に適度な傷がつけられ、この傷から出液した血液が、毛管現象により、貫通孔36ａを介してバイオセンサ36内の体液通路36ｂに導入させられる。貫通孔36ａは穿刺針31ｃが通過する孔であるため、この貫通孔36ａは皮膚の傷、すなわち出液部にきわめて近接している。そうして、前述したように、バイオセンサ36内の体液通路36ｂの実質容積はきわめて小さいため、少量の血液で体液通路36ｂを充満させることが可能である。したがって、出液部の血液量をいちいち黙視確認するまでもなく、皮膚当接面35aを皮膚に押し付けたまま上記の操作をし、かつ皮膚当接面35ａを皮膚に押し付けた状態を所定時間保持するだけで、測定に必要十分な血液をセンサ中の体液通路36ｂに導入することができる。なお、前述したように、吸引シリンダ機構を本体に付加し、装着体30の前面の皮膚当接面35ａの開口36ｍを介して皮膚に負圧を作用させながら上述した操作をすると、鬱血状態の皮膚に穿刺針31ｃで傷を付けることができるため、より充分な量の血液を出液させることができる。
【００４３】
バイオセンサ36内の体液通路36ｂ内において、反応試薬（反応部36ｋ）が血液によって溶解されると、以下の数３に示される酵素反応が開始される結果、反応部36ｋに共存させているフェリシアン化カリウムが還元され、還元型の電子伝達体であるフェロシアン化カリウムが蓄積される。
【００４４】
【数３】

【００４５】
フェロシアン化カリウムの蓄積量は、基質濃度、すなわち血液中のグルコース濃度に比例する。一定時間蓄積された還元型の電子伝達体は、以下の数４に示される電気化学反応により、酸化される。
【００４６】
【数４】

【００４７】
測定装置本体20内の電子回路33は、このとき測定される作用電流から、グルコース濃度（血糖値）を演算・決定し、好ましくはたとえば本体20表面に配置されたＬＣＤ表示器２２に表示する。
【００４８】
このように、上記体液測定装置10によれば、装着体30を本体20の所定部位に装着するという簡単な前準備をした後、装着体30の前面の皮膚当接面35ａを患者の指先や耳たぶ等に押し当てた状態を保持しつつ、あたかも従来のランセットを扱うようにして穿刺針31ｃを突出させるという操作をするだけで、それ以上の操作、あるいは動作を要することなく、血糖値等の体液測定を適正に行うことができる。
【００４９】
図１１ないし図１３は、バイオセンサ36の他の構造例を示す。このバイオセンサ36は、ベース板36Ａと、スペーサ板36Ｂ，36Ｂと、カバー板36Ｃとを備える点では前述のバイオセンサ36と同様であるが、ベース板36Ａには作用極36ｃのみが形成され、カバー板36Ｃとして導電性金属を用いることにより、このカバー板36Ｃの内面を対極36ｄとして機能させている。より具体的には、ベース板36Ａには、図１１に示すようなパターンの作用極36ｃが形成される。そして、図１２および図１３に示すように、この作用極36ｃの内方の一部を露出させるようにして、所定の間隔をあけて２枚のスペーサ板36Ｂ，36Ｂが重ねられる。これにより、作用極36ｃの一部が底面に露出する凹溝36ｅが形成される。作用極36ｃの外方部は露出させられ、コネクタピン25ａ，25ａと接触する電極部36ｆとして機能する。凹溝36ｅの幅、長さ、深さは、それぞれ、前述の実施形態のものと同等に設定され、この凹溝36ｅとカバー体36Ｃとにより、体液通路36ｂが形成される。凹溝36ｅの底部には、反応試薬が塗布された反応部36ｋが形成される。このセンサ36を血糖値測定用に構成する場合、反応試薬として、前述したのと同様のものを用いることができる。カバー体36Ｃの上面適部は、コネクタピン25ａと接触する電極部36ｈとして機能させられる。このバイオセンサ36においても、図１１に良く表れているように穿刺針31ｃが通過する貫通孔36ａが上記体液通路36ｂに隣接して設けられている点もまた、前述の実施形態と同様である。そして、このバイオセンサ36は、前述の実施形態と同様にして、問題なく装着体30の底壁部35に貼着して使用することができる。
【００５０】
なお、図１１ないし図１３の構造のバイオセンサ36において、図１４に示したようにベース板36Ａに形成する作用極36ｃに接触するようにしてフェリシアン化カリウムを含む反応試薬層361k（第１反応部）を形成する一方、カバー体36Ｃの内面に酸化酵素であるグルコースオキシターゼおよびメディエータとしてのフェリシアン化カリウムを含む反応試薬層362k（第２反応部）を形成することによって反応部36ｋを形成する態様とすることも可能である。このようにすれば、酵素反応および電気化学反応を介して作用電流を検出するこの種のバイオセンサ36において、アスコルビン酸の影響を除去したより正確な測定が可能となる。
【００５１】
もちろん、この発明の範囲は上述した実施形態に限定されることはない。実施形態では、血糖値を測定するためのものとして説明されているが、測定対象は血糖値に限定されない。また、装着体の具体的形状およびバイオセンサの具体的構造は、種々変更可能である。本願発明の最も重要なポイントは、本体に装着して使用される好ましくは使い捨ての装着体に穿刺体とバイオセンサとが一体的に組み込まれている点である。
【図面の簡単な説明】
【図１】
本願発明に係る体液測定装置の全体外観図である。
【図２】
穿刺体が退避した状態における装着体の詳細を示す拡大縦断面図であり、図４のII−II線に沿う断面に相当する図である。
【図３】
穿刺体が進出した状態における装着体の詳細を示す拡大縦断面図である。
【図４】
装着体の底面図である。
【図５】
バイオセンサを外した状態での装着体の底面図である。
【図６】
バイオセンサの平面図である。
【図７】
図６のVII −VII 線に沿う断面図である。
【図８】
図７における一点鎖線で囲まれた領域の拡大図である。
【図９】
バイオセンサの分解斜視図である。
【図１０】
電気的な構成を説明するための概略構成図である。
【図１１】
バイオセンサの変形例を示す平面図である。
【図１２】
図１１のXII −XII 線に沿う断面図である。
【図１３】
図１２の一点鎖線Ｂで囲まれた領域の拡大図である。
【図１４】
変形例のバイオセンサにおける反応部の変形例を示す要部を拡大した断面図である。
【符号の説明】
１０ 体液測定装置
２０ 本体
２３ 押圧部（駆動機構を構成する）
２５ａ コネクタピン（本体の端子としての）
３０ 装着体
３１ 穿刺体
３２ 押圧ロッド（駆動機構を構成する）
３３ 電子回路
３５ａ 皮膚当接面
３６ バイオセンサ
３６Ａ ベース板（バイオセンサを構成する）
３６Ｂ スペーサ板（バイオセンサを構成する）
３６Ｃ カバー板（バイオセンサを構成する）
３６ａ 貫通孔（バイオセンサの）
３６ｂ 体液流路（バイオセンサの）
３６ｃ 作用極（バイオセンサの）
３６ｄ 対極（バイオセンサの）
３６ｅ 溝（バイオセンサの）
３６ｋ 反応部（バイオセンサの反応試薬層）
３６ｆ，３６ｈ 端子部（センサの電極としての）
３６１ｋ 第１反応部（変形例のバイオセンサの反応試薬層）
３６２ｋ 第２反応部（変形例のバイオセンサの反応試薬層）
３７ コイルバネ（弾性体としての） [Document name] Specification [Title of invention] Lancet-integrated body fluid measuring device and a body fluid measuring device to be attached to and used [Claims]
1. A body fluid measuring device including a main body and a mounting body to be mounted and used on the main body.
The wearing body includes a skin contact surface, a sensor arranged along the skin contact surface, an advance position where the tip protrudes from the skin contact surface, and a retracted position where the tip is immersed from the skin contact surface. It is equipped with a puncture body that can move between and is urged to the retracted position side by an elastic body.
The main body is a terminal that contacts and conducts to each electrode of a sensor included in the wearable body when the wearable body is mounted, and an electron that determines a measured value based on an electric signal obtained through the terminal. A lancet-integrated body fluid measuring device comprising a circuit and a driving mechanism for driving the puncture body forward to cause the puncture body to take an advanced position.
2. The body fluid measuring device according to claim 1, wherein the puncture body and the elastic body in the wearing body are integrally molded.
3. The wearing body is configured such that the puncture needle of the puncture body retracts into the elastic body and is protected while the puncture body is stationary on the retracted position side. 2. The body fluid measuring device according to 2.
4. The body fluid measuring device according to claim 1, wherein an opening for applying a negative pressure to the skin is formed on the skin contact surface of the wearing body.
5. The body fluid measuring device according to claim 1, wherein the attached body has a cap shape as a whole.
6. The sensor in the wearing body has a plate shape extending along the skin contact surface as a whole, and a body fluid passage facing the reaction portion on the inner surface is formed inside the sensor in the thickness direction thereof. The body fluid measuring device according to any one of claims 1 to 5, wherein a through hole is formed that communicates with the body fluid passage and allows the tip of the puncture body to pass through.
7. The sensor in the mounting body has a base plate having an working electrode and a counter electrode formed on the upper surface thereof, and the base plate so as to face a part of each of the working electrode and the counter electrode to form a groove. It is configured to include a spacer superposed on the surface, a reaction portion in which a reaction reagent layer is formed in a part or all of the groove, and a cover plate superposed on the spacer. 6. A claim 6 in which the enclosed space forms a body fluid passage, and a terminal portion that conducts with the working electrode and the counter electrode and is brought into contact with the terminal of the main body is arranged at an appropriate portion on the upper surface of the base plate. The body fluid measuring device according to.
8. The sensor in the mounting body includes a base plate having a working electrode formed on the upper surface and a spacer superposed on the base plate so as to face a part of the working pole to form a groove. A cover plate which is overlapped with the spacer and has a counter electrode facing the groove on the lower surface, a first reaction portion having a first reagent layer formed in the groove so as to be in contact with the working electrode, and the counter electrode. A second reaction portion having a second reagent layer formed on the lower surface of the cover plate is provided so as to be in contact with the cover plate, and the space surrounded by the groove and the cover plate forms a body fluid passage. On the other hand, a first terminal portion that conducts with the working electrode and is brought into contact with the terminal of the main body is arranged at an appropriate portion on the upper surface of the base plate, and is conductive with the counter electrode and brought into contact with the terminal of the main body. The body fluid measuring device according to claim 6, wherein the second terminal portion is arranged on the upper surface of the cover plate.
9. The body fluid measuring device according to claim 8, wherein the cover plate is formed of a conductor plate, the lower surface thereof functions as a counter electrode, and the appropriate upper surface portion functions as a second terminal portion.
10. The terminal in the main body is movable between an advancing position where its tip protrudes from the main body and a retracting position where the tip of the terminal protrudes from the advancing position, and is always urged in the advancing direction by a spring. The body fluid measuring device according to claim 1.
11. The body fluid measuring device according to any one of claims 1 to 10, which is mounted on a main body and used.
Description: TECHNICAL FIELD [Detailed description of the invention]
[0001]
[Technical field to which the invention belongs]
According to the present invention, it is possible to measure a substance to be detected contained in a body fluid such as a blood glucose concentration (hereinafter referred to as "blood glucose level"), and the body fluid is collected from the skin and measured by an integrated operation. It relates to a lancet-integrated body fluid measuring device configured to be capable of doing so.
0002.
Background of the Invention
In the treatment of diabetes, it is necessary to keep the blood glucose level of the patient within the normal range, and the blood glucose level management by the patient himself is an important treatment method. In particular, when the blood glucose level is maintained in the normal range by insulin injection by the patient himself, it is indispensable to appropriately measure the blood glucose level by the patient himself.
0003
A portable blood glucose measuring device used for such a purpose is already on the market, and an example thereof is shown in, for example, Japanese Patent Publication No. 8-20412. This blood glucose level measuring device is used by inserting a disposable test piece having an enzyme electrode into the main body. When the test piece is brought into contact with the sample blood, a part of the blood is drawn into the reaction part by a capillary phenomenon, and an anodic current is generated through an enzymatic reaction and an electrochemical reaction. This anode current is converted into a blood glucose level in the main body of the apparatus and displayed.
0004
By the way, the sample to be brought into contact with the test piece of the measuring device as described above, that is, blood is generally collected by using an instrument called a lancet, for example, as shown in Japanese Patent Application Laid-Open No. 9-266898. Is. This lancet is a device for making (damaging) a small hole in the skin such as the fingertip of a patient, and the blood discharged from the hole made in this way is brought into contact with a predetermined part of the above-mentioned test piece. Therefore, the self-measurement of the blood glucose level can be performed relatively easily.
0005
However, in the conventional general self-monitoring method of blood glucose level described above, since the lancet for collecting blood as a sample and the measuring device are separate bodies, the lancet is combined with the inconvenience of having to carry both of them. It is necessary to perform two actions, one is to damage the skin and the other is to touch the blood discharged from the wound with the test piece, and there is still room for improvement in usability. In particular, regarding the action of touching the test piece with blood, it is necessary to bring the required amount of blood into contact with the specified part of the test piece, and such an action is performed for an unfamiliar patient or a patient with poor eyesight. Or, when blood is collected from an earlobe that cannot be directly seen by the patient, it is extremely difficult to allow the blood discharged from the above-mentioned wound to come into contact with the test piece quickly and appropriately.
0006
Further, since the test piece is configured to draw blood from the hole at the tip to the surface enzyme electrode provided in the reaction part by a capillary phenomenon, it is necessary to bring the required amount of blood to the reaction part from 3 to 3. It is necessary to bring 5 μl of blood into contact with the test piece. If this amount of blood is insufficient, or if this amount of blood is not properly adhered to a small area surrounding the tip hole of the test piece, accurate measurement may not be possible. This situation can occur frequently, especially when the amount of blood discharged from the wound is insufficient, such as in infants and the elderly.
0007
As an attempt to solve the above-mentioned problems, Japanese Patent Application Laid-Open No. 10-28883 states that the sensor incorporated in the device can be used for the skin simply by scratching the skin with the lancet incorporated in the device. A lancet-integrated blood glucose meter that measures the blood discharged from the skin has been proposed. However, in the case of the one shown in the same publication, the lancet needle and the sensor must be set separately at a predetermined position of the device at the time of use, and there is still room for improvement in terms of usability.
0008
The invention of the present application was conceived under such circumstances, and it is possible to further improve usability by making the operation required for the patient for measurement simpler and significantly increase the required sample amount. The challenge is to provide a lancet-integrated body fluid measuring device that can reduce the amount and increase the reliability of measurement.
0009
[Disclosure of Invention]
In order to solve the above problems, the present invention takes the following technical measures.
0010
The body fluid measuring device provided by the present invention is a body fluid measuring device including a main body and a wearing body attached to and used by the main body, and the wearing body is a skin contact surface and the skin contact. It is possible to move between the sensor arranged along the surface and the advance position where the tip protrudes from the skin contact surface and the retracted position where the tip is immersed from the skin contact surface, and the retracted position side is provided by the elastic body. The main body is provided with a piercing body that is urged to the body, and the main body is provided with a terminal that contacts and conducts to each electrode of a sensor provided by the mounting body when the mounting body is mounted, via this terminal. It is characterized by including an electronic circuit that determines a measured value based on an electric signal obtained by the piercing body, and a driving mechanism for driving the piercing body forward and causing the piercing body to take an advanced position.
0011
The wearer is provided, for example, as a disposable consumable. In the measurement, the user attaches the above-mentioned body to the main body. If while pressing the skin contact surface to the skin such as the fingertip or earlobe Ru actuates the drive mechanism of the body, scratches its tip from the skin contact surface puncture body in the retracted position is caused to advance projects to the skin Attach. At the next moment, the puncture body returns to the retracted position by the action of the elastic body. If the device is left in place, the blood effluent from the skin will permeate the sensor and the sensor will output a reaction current. This current is converted into a specific component concentration in blood by an electronic circuit and displayed on a display arranged on the surface of the main body, for example.
0012
As described above, in the body fluid measuring device of the present invention, since the puncture body and the sensor are integrally incorporated in the wearing body in advance, the user only needs to attach the wearing body to the main body for measurement, and the lancet. Compared to the case where the lancet needle and the sensor are used separately, and also when compared with the conventional lancet-integrated blood measuring device, which requires the lancet needle and the sensor to be set separately at a predetermined part of the device. Its usability is significantly improved.
0013
In a preferred embodiment, the skin contact surface of the wearing body is formed with an opening for applying a negative pressure to the skin. With this configuration, the skin surface can be in a congested state and can be injured by the puncture body, so that a sufficient amount of blood can be discharged, and the measurement becomes more reliable.
0014.
In a preferred embodiment, the sensor in the wearing body has a plate shape extending along the skin contact surface as a whole, and a body fluid passage in which the reaction portion faces the inner surface is provided inside in the thickness direction thereof. It is formed, and has a structure in which a through hole is formed so as to communicate with the body fluid passage and allow the tip of the puncture body to pass through.
0015.
According to this configuration, the through hole through which the puncture body passes and the body fluid passage in the sensor communicate with each other, so that the blood discharged from the wound on the skin directly enters the through hole and subsequently reacts. The body fluid passage facing the part is filled. Therefore, the distance from the skin wound to the reaction site is significantly shortened. Further, since the sensor itself has a plate shape, the volume of the body fluid passage can be reduced. Therefore, the blood volume required for measurement can be significantly reduced.
0016.
In a preferred embodiment, the sensor in the mounting body further forms a groove with the working electrode and the counter electrode formed on the upper surface and a part of each of the working electrode and the counter electrode facing each other. It is configured to include a spacer superposed on the base plate, a reaction portion in which a reaction reagent layer is formed in a part or all of the groove, and a cover plate superposed on the spacer, and the groove and the cover are provided. The space surrounded by the plate forms a body fluid passage, and a terminal portion that conducts with the working electrode and the counter electrode and is brought into contact with the terminal of the main body is arranged at an appropriate portion on the upper surface of the base plate.
[0017]
Further, in another preferred embodiment, the sensor in the mounting body is mounted on the base plate so that the working electrode is formed on the upper surface and a groove is formed so as to face a part of the working electrode. The first reagent layer is formed in the groove so as to be in contact with the spacer, the cover plate which is overlapped with the spacer and has a counter electrode formed on the lower surface facing the groove, and the working electrode. A reaction portion and a second reaction portion having a second reagent layer formed on the lower surface of the cover plate so as to be in contact with the counter electrode are provided, and a space surrounded by the groove and the cover plate is formed. While forming a body fluid passage, a first terminal portion that conducts with the working electrode and is brought into contact with the terminal of the main body is arranged at an appropriate portion on the upper surface of the base plate, and also conducts with the counter electrode and conducts with the main body. A second terminal portion that comes into contact with the terminal of the cover plate is arranged on the upper surface of the cover plate.
0018
According to this structure, together with the work for electrode or the counter electrode by such subjected to screen printing base plate can be easily formed by a simple method of laminating plate-shaped parts, the body fluid passage inside the thickness direction It is possible to easily manufacture a plate-shaped sensor in which the is properly formed.
0019
When the body fluid measuring device of the present invention is configured for blood glucose measurement, for example, a reaction reagent containing glucose oxidase, which is an oxidase, and potassium ferricyanide, which is a mediator, is adopted as the reaction reagent to be arranged in the reaction part of the sensor. To.
0020
When the reaction part is dissolved by blood, the enzymatic reaction shown in Equation 1 is started, and as a result, potassium ferricyanide coexisting in the reaction layer is reduced, and potassium ferrocyanide, which is a reduced electron carrier, is accumulated. To. The amount is proportional to the substrate concentration, that is, the glucose concentration in the blood. The reduced electron carrier accumulated for a certain period of time is oxidized by the electrochemical reaction shown in Equation 2. The electronic circuit in the main body of the measuring device calculates and determines the glucose concentration (blood glucose level) from the anodic current measured at this time, and displays it on the display arranged on the surface of the main body as described above.
0021.
[Number 1]

0022.
[Number 2]

[0023]
As described above, according to the body fluid measuring device according to the present invention, a state in which a wearable body provided for disposable use is attached to the main body and the skin contact surface of the wearable body is pressed against a patient's fingertip or earlobe. It is possible to properly measure body fluids such as blood glucose level without any further operation or operation by simply performing the operation of protruding the puncture body as if handling a conventional lancet while holding the above. it can. In addition, since the amount of sample required for measurement is small, the burden on the patient is reduced.
0024
Other features and advantages of the present invention will become apparent from the detailed description given below with reference to the drawings.
0025
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. FIG. 1 is an overall external view of the body fluid measuring device according to the present invention, and FIG. 2 is an enlarged vertical cross-sectional view showing details of the wearing body in a state where the puncture body is retracted. The corresponding figure, FIG. 3, is an enlarged vertical sectional view showing the details of the wearing body in the state where the puncture body is advanced, FIG. 4 is a bottom view of the wearing body, and FIG. 5 is a view of the wearing body in the state where the sensor is removed. It is a bottom view.
0026
As shown in FIGS. 1 to 3, the body fluid measuring device 10 according to the present invention is used in combination with the main body 20 and the mounting body 30. The main body 20 has switch buttons, an LCD display 22, and the like arranged on the upper surface thereof. A tubular portion 21 is formed so as to extend from the front portion of the main body 20, and a cap-shaped mounting body 30, which will be described in detail later, is attached to the tip portion thereof. Further, inside the main body 20, a drive mechanism (23, 32) for driving the puncture body 31 included in the mounting body 30 forward, a circuit such as a microcomputer, and the like are built-in. In FIG. 1, reference numeral 23 constitutes a part of the drive mechanism and indicates a pressing portion for the user to manually press.
[0027]
2 to 5 show details of an example of the wearing body 30. The mounting body 30 has a substantially cap shape including a cylindrical portion 34 and a bottom wall portion 35 located so as to close the tip of the cylindrical portion 34, and the main portion thereof is manufactured by resin molding. The inner diameter of the cylindrical portion 34 corresponds to the outer diameter of the front tubular portion 24 of the main body 20, and the cylindrical portion 34 can be easily mounted by covering the front tubular portion 24. The outer surface of the bottom wall portion 35 is made to function as a skin contact surface 35a that contacts the user's skin.
[0028]
The puncture body 31 and the biosensor 36 are integrally incorporated in the bottom wall portion 35 of the cap-shaped mounting body 30. A cylindrical recessed portion 35A having a cylindrical wall 35b and a bottom wall 35c is formed in the bottom wall portion 35 at the center position of the mounting body 30, and a central hole 35d is formed in the bottom wall 35c of the depressed portion 35A. It is open.
[0029]
On the other hand, the puncture body 31 is made of metal on a resin guide body 31A having a guide shaft portion 31a slidably fitted in the center hole 35d and a flange portion 31b integrally formed at one end of the guide shaft portion 31a. The puncture needle 31c of the above is integrally inserted, and the elastic body 37 interposed between the flange portion 31b and the upper surface of the plate-shaped biosensor 36 described later is always at the retracted position shown in FIG. 2, that is, the flange. The portion 31b is punctured toward a position where it abuts on the bottom wall 35c of the depressed portion 35A. At this retracted position, the rear end of the guide shaft portion 31a protrudes inward of the bottom wall 35c, and the puncture needle 31c retracts to the back side of the plate-shaped biosensor 36 described later. As an embodiment of the elastic body 37 that urges the puncture body 31 toward the retracted position as described above, a compression coil spring made of metal or resin is used as shown in FIGS. 2 and 3, and urethane foam or the like is used. It can be in the form. In this way, if the elastic body 37 is in the form of urethane foam and the puncture needle 31c is buried inside the urethane foam when the puncture body 31 takes the retracted position, the puncture needle has an opportunity to touch an external object. It is hygienic because it can be reduced. Further, the elastic body 37 can be in the form of a plate-shaped spring integrally molded with the resin guide body 31A.
[0030]
A plate-shaped biosensor 36 is also attached to the bottom wall portion 35 of the mounting body 30 so as to cover the recessed portion 35A in which the puncture body 31 is housed. As shown in FIGS. 6 to 8, the biosensor 36 communicates with the through hole 36a through which the puncture needle 31c of the puncture body 31 can pass, and communicates with the through hole 36a so that the thickness is parallel to the bottom wall portion 35. It is provided with a body fluid passage 36b extending to the surface, and has a configuration in which a reaction portion 36k is formed on the inner wall of the body fluid passage 36b.
0031
More specifically, the biosensor 36 forms an insulating base plate 36A having a working electrode 36c and a counter electrode 36d formed on the upper surface thereof, and a groove 36e that exposes a part of the working electrode 36c and the counter electrode 36d. It includes plate-shaped spacers 36B and 36B laminated on the insulating base plate 36A, and plate-shaped covers 36C further laminated on the plate-shaped spacers 36B and 36B. Hereinafter, the manufacturing process of this plate-shaped biosensor 36 will be described.
[0032]
As shown in FIG. 9, for example, a base plate 36A having a rectangular shape in a plan view made of a resin insulating sheet having a thickness of 0.2 mm is prepared. A through hole 361a having a diameter of, for example, 1.5 mm is formed in advance in the base plate 36A. On the upper surface of the base plate 36A, a working electrode 36c and a counter electrode 36d are formed in a film shape by a screen printing method using graphite ink. The working pole 36c has a planar shape in which a fine protrusion 36g extends from an end region 36f (a region where only the diagonal line is applied to the working pole 36c) to be a terminal portion, while the counter electrode 36d has a planar shape. It has a planar form having protrusions 36i and 36i extending in a bifurcated manner so as to sandwich the protrusion 36g on the working pole 36c side from the end region 36h (the region where only the counter electrode 36d is shaded) that should be the terminal portion. There is. The through hole 361a is located close to one of the protrusions 36i of the counter electrode 36d. The working electrode 36c and the counter electrode 36d can also be formed by depositing a noble metal such as gold or platinum and etching to form a predetermined pattern.
0033
Next, the resist layer 36j (with the solid line) leaving the strip-shaped regions where the protruding portions 36g, 36i, 36i of the working pole 36c and the counter electrode 36d are lined up in the vertical direction and the end regions 36f, 36h of the working pole 36c and the counter electrode 36d. The area shaded by the alternate long and short dash line) is printed and formed.
0034
Subsequently, the spacer plates 36B and 36B having the same planar shape as the resist layer 36j are arranged so as to be overlapped with the resist layer 36j. As the spacer plate 36B, for example, a resin plate having a thickness of 0.2 mm is adopted, and a double-sided tape having an adhesive layer on the front and back surfaces is used. As a result, a concave groove 36e sandwiched between the spacer plates 36B and 36B is formed (see FIG. 8), and the protrusions 36g and 36i of the working electrode 36c and the counter electrode 36d are formed in the band-shaped region at the bottom of the concave groove 36e. 36i will be exposed side by side. The width of the concave groove 36e is set to, for example, 1.5 mm, and the length is set to, for example, 3 mm.
0035.
Next, the reaction reagent layer 36k as shown well in FIG. 8 is formed in the band-shaped region at the bottom of the concave groove 36e. When configured as a sensor for blood glucose measurement, this reaction reagent contains glucose oxidase, which is an oxidase, and potassium ferricyanide, which is a mediator. The reaction reagent layer 36k is formed by, for example, a dispensing method.
0036
Next, as shown in FIG. 9, the cover plate 36C having a rectangular shape in a plan view having the through hole 361a of the base plate 36A and the corresponding through hole 362b are overlapped with each other so as to be overlapped with the spacer plates 36B and 36B. This biosensor 36 is completed. That is, as shown in FIGS. 6 to 8, a body fluid having a horizontally long rectangular cross section extending in the vertical direction by closing the concave groove 36e formed by the base plate 36A and the spacer plates 36B and 36B with the cover plate 36C. A passage 36b is formed, and a reagent layer 36k (reaction part) in contact with the working electrode 36c and the counter electrode 36d is formed on the inner surface of the body fluid passage 36b, and the body fluid passage 36b is the plate-shaped biosensor 36 of the plate-shaped biosensor 36. It will be communicated with the through hole 36a. Further, the side opposite to the position of the through hole 36a in the body fluid passage 36b is opened, and as will be described later, the body fluid (blood) flows into the body fluid passage 36b or the reaction portion 36k via the through hole 36a due to a capillary phenomenon. Encourage them to be introduced. The volume of the body fluid passage 36b is 1.5 mm × 3 mm × 0.2 mm = 0.9 μl from the width and length of the recessed groove 36e and the thickness dimensions of the spacer plates 36B and 36B described above, but the reagent layer 36k When the solid content volume of about 0.2 μl is subtracted, the actual volume of the body fluid passage 36b becomes extremely small, about 0.7 μl.
0037
In the plate-shaped biosensor 36 formed as described above, as shown in FIG. 2, the position of the puncture needle 31c and the position of the through hole 36a of the biosensor 36 are located on the bottom wall portion 35 of the mounting body 30. It is attached so that it matches. As shown in FIGS. 4 and 5, the bottom wall portion 35 of the mounting body 30 has a working electrode 36c and a terminal portion 36f for the counter electrode 36d exposed at both ends of the base plate 36A of the biosensor 36. Round holes 362c and 362d corresponding to 36h are formed. The round holes 362c and 362d are for bringing the tips of the connector pins 25a and 25a on the main body 20 side into contact with the terminal portions 36f and 36h when the mounting body 30 is mounted on the main body 20. The bottom wall portion 35 of the mounting body 30 is also formed with bow-shaped openings 36 m and 36 m so as to sandwich the biosensor attachment region. This opening 36 m is for applying a negative pressure to the skin in a state where the bottom wall portion 35 of the wearing body 30 is brought into contact with the skin as the skin contact surface 35a.
[0038]
On the other hand, a pair of pin connectors 25, 25 are incorporated in the tubular portion 21 of the main body 20 so that the tips of the connector pins 25a, 25a elastically project to the front surface of the tubular portion 21. The pin connectors 25 and 25 are connected to the electronic circuit 33 as shown in FIG. This electronic circuit 33 is composed of a microcomputer or the like, and as will be described later, a calibration curve is used to measure a measured value of a substance to be detected such as a blood glucose level from an action current generated by an enzymatic reaction and an electrochemical reaction generated in the biosensor 36. At the same time as deciding, it has a function to display this on the display 22 arranged on the surface of the main body 20. Further, as shown in FIGS. 2 and 3, the pressing rod 32, which is pressed and driven by the pressing portion 23, is movable in the axial direction (direction indicated by the arrow in the drawing) and is movable in the main body 20. The drive mechanisms 23 and 32 are constructed by being incorporated while being constantly urged to the rear side by a spring. The drive mechanisms 23 and 32 are not limited to this, and a pressing rod 32 is provided so as to be movable in the axial direction and elastically return to the neutral position in the axial direction, and the pressing rod 32 is pulled backward. By holding the latch and pressing the latch release button, the pressing rod 32 is vigorously fired forward, and the pressing rod 32 vigorously hits the rear end of the guide shaft portion 31a of the puncture body 31, and the puncture needle 31c is accompanied by this. Can be configured to momentarily project from the skin contact surface 35a. Further, by incorporating a suction cylinder mechanism (not shown) in the main body 20, it is possible to apply a negative pressure to the tip of the tubular portion 21. Further, the terminal provided on the main body 20 so as to make conductive contact with the terminal portion of the biosensor 36 when the mounting body 30 is mounted on the main body 20 is in the form of a pin connector in which the pin always protrudes elastically as described above. For example, in conjunction with the mounting of the mounting body 30 on the main body 20, the terminal pin is retracted into the main body when the mounting body 30 is not mounted, and when the mounting body 30 is mounted, the terminal pin is moved to the main body. It is also possible to configure the biosensor so that it protrudes from the terminal and makes an appropriate conductive contact with the terminal portion of the biosensor.
[0039]
Next, the usage or operation of the body fluid measuring device 10 having the above configuration will be described with reference to FIGS. 1 to 4.
0040
The attachment body 30 is provided as a disposable consumable item, and when using the body fluid measuring device 10, the user attaches the attachment body 30 to the tubular portion 21 of the main body 20 (see FIG. 1). Since the mounting body 30 has a cap shape in the above embodiment, such mounting work can be easily performed. When the mounting member 30 is mounted, based biosensor 36 via the main body side of the connector pins 25a as appearing in FIG. 2, round holes 362c of the bottom wall portion 35 of the tip of the 25a is mounted body 30, the 362d The plate 36A automatically contacts the terminal portions 36f and 36h arranged on the upper surfaces of both ends.
[0041]
The pressing portion 23 is pressed with the surface of the bottom wall portion 35 of the wearing body 30, that is, the skin contact surface 35a, pressed against an appropriate portion of the patient's skin, for example, a fingertip or an earlobe. Then, the tip of the pressing rod 32 inside the main body 20 pushes the rear end of the guide shaft portion 31a of the puncturing body 31, and the puncturing body has a stroke until the pressing rod 32 comes into contact with the back side of the depressed portion 35A of the mounting body 30. Push 31 forward against the elasticity of the elastic body 37. At this time, the puncture needle 31c of the puncture body 31 projects by a predetermined length from the lower surface of the biosensor 36, that is, the skin contact surface 35a, through the through hole 36a of the biosensor 36 (state of FIG. 3). When the pressure on the pressing portion 23 is released, the pressing rod 32 returns to its original position by the elasticity of the spring, and the puncture body 31 also immerses the puncture needle 31c from the skin contact surface 35a by the elasticity of the elastic body 37. It returns to the retracted position (state in FIG. 2).
[0042]
The protrusion of the puncture needle 31c from the skin contact surface 35a causes an appropriate damage to the skin, and the blood discharged from this wound is discharged from the wound through the through hole 36a through the body fluid passage 36b in the biosensor 36. Introduced to. Since the through hole 36a is a hole through which the puncture needle 31c passes, the through hole 36a is extremely close to the wound on the skin, that is, the liquid discharge portion. Then, as described above, since the parenchymal volume of the body fluid passage 36b in the biosensor 36 is extremely small, it is possible to fill the body fluid passage 36b with a small amount of blood. Therefore, Even without each time Mokushi check blood volume of exudates unit, the skin contact surface 35a and the above operation while pressed against the skin, and conditions for a predetermined time holding the skin contact surface 35a is pressed against the skin Only by doing so, sufficient blood necessary for measurement can be introduced into the body fluid passage 36b in the sensor. As described above, when the suction cylinder mechanism is added to the main body and the above operation is performed while applying a negative pressure to the skin through the opening 36 m of the skin contact surface 35a on the front surface of the wearing body 30, a blood stasis state occurs. it is possible to scratch at puncture puncture needle 31c in the skin, can be exudates more sufficient amount of blood.
[0043]
When the reaction reagent (reaction unit 36k) is dissolved by blood in the body fluid passage 36b in the biosensor 36, the enzymatic reaction shown in Equation 3 below is started, and as a result, the ferricyanide coexisting in the reaction unit 36k. Potassium ferricyanide is reduced and potassium ferricyanide, which is a reduced electron carrier, is accumulated.
[0044]
[Number 3]

0045
The amount of potassium ferrocyanide accumulated is proportional to the substrate concentration, that is, the glucose concentration in the blood. The reduced electron carrier accumulated for a certain period of time is oxidized by the electrochemical reaction shown in Equation 4 below.
[0046]
[Number 4]

[0047]
Electronic circuit 33 in the measuring apparatus body 20, displays the work for current to be measured at this time, is calculated and determined glucose concentration (blood sugar level), preferably in the LCD display 22 disposed on the body 20 surface e.g. To do.
0048
As described above, according to the body fluid measuring device 10, after making a simple preparation for attaching the wearing body 30 to a predetermined portion of the main body 20, the skin contact surface 35a on the front surface of the wearing body 30 is applied to the patient's fingertip or the like. Just by operating the puncture needle 31c to project the puncture needle 31c as if handling a conventional lancet while maintaining the state of being pressed against the ear canal, etc., no further operation or operation is required, and the blood glucose level, etc. Body fluid measurement can be performed properly.
[0049]
11 to 13 show other structural examples of the biosensor 36. This biosensor 36 is similar to the above-mentioned biosensor 36 in that it includes a base plate 36A, spacer plates 36B and 36B, and a cover plate 36C, but only the working electrode 36c is formed on the base plate 36A. By using a conductive metal as the cover plate 36C, the inner surface of the cover plate 36C functions as a counter electrode 36d. More specifically, the base plate 36A is formed with a working electrode 36c having a pattern as shown in FIG. Then, as shown in FIGS. 12 and 13, the two spacer plates 36B and 36B are overlapped with a predetermined interval so as to expose a part of the inside of the working electrode 36c. As a result, a concave groove 36e is formed in which a part of the working electrode 36c is exposed on the bottom surface. The outer portion of the working electrode 36c is exposed and functions as an electrode portion 36f that comes into contact with the connector pins 25a and 25a. The width, length, and depth of the concave groove 36e are set to be the same as those of the above-described embodiment, and the concave groove 36e and the cover body 36C form the body fluid passage 36b. At the bottom of the groove 36e, a reaction portion 36k coated with a reaction reagent is formed. When this sensor 36 is configured for blood glucose measurement, the same reaction reagent as described above can be used as the reaction reagent. The upper surface suitable portion of the cover body 36C is made to function as an electrode portion 36h in contact with the connector pin 25a. Also in this biosensor 36, as shown well in FIG. 11, a through hole 36a through which the puncture needle 31c passes is provided adjacent to the body fluid passage 36b, which is also the same as the above-described embodiment. .. Then, the biosensor 36 can be used by being attached to the bottom wall portion 35 of the mounting body 30 without any problem in the same manner as in the above-described embodiment.
0050
In the biosensor 36 having the structure of FIGS. 11 to 13, as shown in FIG. 14, the reaction reagent layer 361k containing potassium ferricyanide is brought into contact with the working electrode 36c formed on the base plate 36A (first reaction unit). ) Is formed, while the reaction reagent layer 362k (second reaction part) containing glucose oxidase which is an oxidase and potassium ferricyanide as a mediator is formed on the inner surface of the cover body 36C to form the reaction part 36k. It is also possible. In this way, a biosensor 36 of this type that detects the acting current via an enzymatic reaction and an electrochemical reaction enables more accurate measurement without the influence of ascorbic acid.
0051
Of course, the scope of the present invention is not limited to the above-described embodiments. In the embodiment, it is described as for measuring the blood glucose level, but the measurement target is not limited to the blood glucose level. Further, the specific shape of the wearing body and the specific structure of the biosensor can be variously changed. The most important point of the present invention is that the puncture body and the biosensor are integrally incorporated in a preferably disposable wearing body which is used by being mounted on the main body.
[Simple explanation of drawings]
FIG. 1
It is an overall external view of the body fluid measuring apparatus which concerns on this invention.
FIG. 2
It is an enlarged vertical cross-sectional view which shows the detail of the wearing body in the state where the puncture body is retracted, and is the figure corresponding to the cross section along the line II-II of FIG.
FIG. 3
It is an enlarged vertical sectional view which shows the detail of the wearing body in the state where the puncture body is advanced.
FIG. 4
It is a bottom view of the wearing body.
FIG. 5
It is the bottom view of the wearing body with the biosensor removed.
FIG. 6
It is a top view of a biosensor.
FIG. 7
It is sectional drawing which follows the line VII-VII of FIG.
FIG. 8
It is an enlarged view of the region surrounded by the alternate long and short dash line in FIG. 7.
FIG. 9
It is an exploded perspective view of a biosensor.
FIG. 10
It is a schematic block diagram for demonstrating the electrical configuration.
FIG. 11
It is a top view which shows the modification of the biosensor.
FIG. 12
It is sectional drawing which follows the XII-XII line of FIG.
FIG. 13
It is an enlarged view of the region surrounded by the alternate long and short dash line B in FIG.
FIG. 14
It is an enlarged sectional view of the main part which shows the deformation example of the reaction part in the biosensor of the modification example.
[Explanation of symbols]
10 Body fluid measuring device 20 Main body 23 Pressing part (constituting a drive mechanism)
25a connector pin (as a terminal on the main unit)
30 Mounting body 31 Puncture body 32 Pressing rod (constituting a drive mechanism)
33 Electronic circuit 35a Skin contact surface 36 Biosensor 36A Base plate (constituent of biosensor)
36B spacer plate (constituting a biosensor)
36C cover plate (constituting a biosensor)
36a through hole (of biosensor)
36b Body fluid flow path (of biosensor)
36c working electrode (of biosensor)
36d counter electrode (of biosensor)
36e groove (of biosensor)
36k reaction section (biosensor reaction reagent layer)
36f, 36h terminal (as sensor electrode)
361k 1st reaction part (reaction reagent layer of biosensor of modified example)
362k 2nd reaction part (reaction reagent layer of biosensor of modified example)
37 Coil spring (as an elastic body)

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