JP3969879B2

JP3969879B2 - Bath accident detection device

Info

Publication number: JP3969879B2
Application number: JP02618499A
Authority: JP
Inventors: 成野波; 弘昭出馬
Original assignee: Osaka Gas Co Ltd
Current assignee: Osaka Gas Co Ltd
Priority date: 1999-02-03
Filing date: 1999-02-03
Publication date: 2007-09-05
Anticipated expiration: 2019-02-03
Also published as: JP2000217728A

Description

【０００１】
【発明の属する技術分野】
本発明は、浴槽内での入浴者の異状による頭部の異状沈水を早期に検出し、その異状沈水による事故を未然に防止可能な浴槽内事故検出装置に関する。
【０００２】
【従来の技術】
家庭内での不慮の事故死の一番の原因は入浴中の浴槽内での溺死である。入浴中の死亡は、上記した不慮の事故死である溺死と、心疾患等の入浴中に起こした病死に区分される。これらの合計である入浴死は全国で年間約一万人にのぼり、件数では交通事故死に匹敵する。特に、高齢者の入浴死が多く、大きな問題となっている。入浴死は冬場に多く発生し、入浴行為に伴う血圧変動の大きさが起因している。
特に、入浴中におけるリスクの高い行為として、浴槽に浸かった状態から浴槽から出ようとして立ち上がる行為である。浴槽に浸かった状態では、温熱効果により末梢血管が拡大して血行が良くなり血圧が低下する。更に、その状態において立ち上がると重力の影響で血が下部に移動することにより、脳及び心臓が虚血状態に陥り、脳疾患や心疾患を引き起こす可能性が高まる。健常者でも浴槽から出る際に立ちくらみ等の症状を起こすことがある。浴槽内で意識を失うと、浴槽内に倒れ溺死に至ることが多い。浴槽内で倒れても、浴槽の縁等に頭部や肩が引っ掛かり溺死に至るのを免れることもある。浴槽内で溺死したケースを調べると、長手方向の寸法が短く深い和式の浴槽ではうつ伏せになって溺死し、長手方向の寸法が長く浅い洋式の浴槽では仰向けになって溺死する場合が多い。洗い場で病死或いは事故死する場合もあるが、浴室での死亡は圧倒的に浴槽内での死亡が多い。
【０００３】
そこで、かかる浴槽内事故を早期に発見するための異状検出装置や、更に当該事故を防止するための浴室安全装置が提案されている。例えば、異状検出装置として、特開平８−５０６９３号公報に開示されている浴室の異状検出装置がある。また、浴室安全装置として、特開平８−６６３２３号公報に開示されている浴室安全装置がある。
この従来の異状検出装置は、浴槽周辺等の浴室内部に人体検出センサ（赤外線センサや光センサ等）を多数配置し、各人体検出センサが人体を検出すると作動し、全ての人体検出センサの作動パターンを解析することにより異状を検出する構成となっている。例えば、洗い場で転倒した場合には、洗い場周辺の壁面の低い位置に設置した多数の人体検出センサが長時間作動してその作動パターンを解析することにより異状を検出する。また、浴槽内で入浴者が動かなくなった場合には、浴槽周辺或いは浴槽上部に設置した多数の人体検出センサが長時間作動してその作動パターンを解析することにより異状を検出する。
また、前記従来の浴室安全装置は、浴槽内面に、浴槽の水位を検知する水位検知手段と、入浴者の頭部の位置を検知するように多数個配置された発光素子と受光素子からなる位置検知手段とを備え、入浴者の頭部の位置と水位を比較して頭部が水中に沈んでいるか否かを判定し、頭部が一定時間以上沈水している場合に、警報発信とともに浴槽水の強制排水を行い、更に浴室内の暖房を行うというものである。
【０００４】
【発明が解決しようとする課題】
しかしながら、前記従来の異状検出装置は、ホテルや老人センタ等の新設の浴室を対象とした大掛かりなシステムで、家庭の既設の浴室に設置できないという問題があった。また、検出精度を向上させるには、浴室内に人体検出センサを多数配置しなければならず、装置コストが高騰するという問題があった。
また、前記従来の浴室安全装置においても、浴槽水位が変動するため位置検知手段を多数個設ける必要がある。また、赤外線センサ等の所定波長の狭いビームを受光する受光素子は水滴や汚れの付着により受光動作不良となる虞が有り、例えば、水面より上の受光素子が受光動作不良となると頭部位置が誤検出され、頭部が水中に沈んでいるか否か誤判定する危険がある。
【０００５】
本発明は、上述の問題点に鑑みなされたものであり、その目的は、浴槽内での溺死に至る可能性の高い入浴者の頭部の異状沈水を確実に早期発見可能な浴槽内事故検出装置を提供し、更には、かかる入浴者を早期に救助可能な浴槽内事故検出装置を提供する点にある。
【０００６】
【課題を解決するための手段】
この目的を達成するための本発明に係る浴槽内事故検出装置の第一の特徴構成は、特許請求の範囲の欄の請求項１に記載した如く、浴槽内にいる入浴者の浴槽水面下にある身体の位置を検出可能な第１位置検出手段と、前記入浴者の頭部の位置を検出可能な第２位置検出手段と、前記第１位置検出手段と前記第２位置検出手段の両検出出力に基づいて前記頭部の異状沈水を判定する判定手段と、前記判定手段の判定結果に基づいて前記浴槽内の湯水を強制的に排水する強制排水手段と、前記強制排水手段の強制排水状態を解除する解除手段とを備えてなり、前記第１位置検出手段は、対面する物体に対して超音波信号を送信可能であって且つ前記物体で反射した超音波信号を受信可能な第１センサ部を前記浴槽内の入浴時における通常水位の下限より下位位置に備え、前記物体までの距離を測定し、その距離が所定値より短いことによって前記浴槽内における前記入浴者の存在を検知し、前記第２位置検出手段は、対面する物体に対して超音波信号を送信可能であって且つ前記物体で反射した超音波信号を受信可能な第２センサ部を前記通常水位の上限より上位位置に備え、前記物体までの距離を測定し、その距離が所定値に対して許容誤差範囲内にあることによって前記入浴者の頭部が沈水していることを検知し、前記判定手段は、前記第１位置検出手段が前記浴槽内における前記入浴者の存在を検知し、且つ、前記第２位置検出手段が前記入浴者の頭部が沈水していることを検知した場合であって、その状態が所定時間継続した場合に前記入浴者が異常沈水状態であると判定し、強制排水信号を前記強制排水手段に対して出力し、前記強制排水手段による強制排水が開始した後、前記第１位置検出手段が前記物体までの距離が見かけ上長くなったことを検知することにより、前記判定手段が前記異状沈水状態から開放されたと判定した場合に、前記解除手段によって強制排水状態が解除される点にある。
【０００７】
尚、入浴時における通常水位とは、浴槽内に入浴のために給湯給水された状態における入浴中の通常の水位である。また、本発明の目的より、その下限とは、頭部が沈水可能な程度の水深に達している水位を意味する。但し、その下限より浅い水深であれば頭部が沈水しないことを保証する水位ではない。また、この通常水位の下限は当然に浴槽の形状や大きさによって変動する。
【０００９】
同第二の特徴構成は、特許請求の範囲の欄の請求項２に記載した如く、上記第一の特徴構成に加えて、前記判定手段の判定結果に基づいて緊急情報を出力する緊急情報出力手段を備えてなる点にある。
【００１０】
同第三の特徴構成は、特許請求の範囲の欄の請求項３に記載した如く、上記第一または第二の特徴構成に加えて、前記第１位置検出手段は前記浴槽内の水温を検出して前記第１センサ部が送受信する超音波信号の伝搬速度を補正する第１温度補正手段を備え、前記第２位置検出手段は前記第２センサ部の周囲の気温を検出して前記第２センサ部が送受信する超音波信号の伝搬速度を補正する第２温度補正手段を備えている点にある。
【００１１】
同第四の特徴構成は、特許請求の範囲の欄の請求項４に記載した如く、上記第一から第三の何れか一つの特徴構成に加えて、前記第２センサ部は超音波の出射ビームの中心軸が水平になるように設置されてある点にある。
【００１３】
同第五の特徴構成は、特許請求の範囲の欄の請求項５に記載した如く、上記第一の特徴構成に加えて、前記判定手段は、前記入浴者が沈水状態であると判定した場合に最初に所定の警告音または警告メッセージを発生し、前記沈水状態がさらに所定時間継続した場合は強制排水を開始するように前記強制排水手段に強制排水信号を送信する点にある。
【００１４】
以下に作用並びに効果を説明する。
本発明の特徴構成によれば、先ず、第１位置検出手段の第１センサ部が浴槽内の水面下に設置されているため、入浴者の浴槽水面下にある身体、例えば、胴部や手足の位置が検出でき、当該位置より入浴者の存在を確認でき、第２位置検出手段の第２センサ部が浴槽水面上に設置されているため、浴槽水面上の頭部の位置を検出できるのである。つまり、第２位置検出手段が検出した頭部位置が入浴者の頭部が存在する範囲外であるか、或いは、検出不能である場合は、入浴者の頭部が浴槽水面下に沈水しているか、または、入浴者が浴槽内にいないと判断でき、第１位置検出手段が入浴者の存在を確認した場合は、入浴者の頭部が浴槽水面下に沈水していると判定する。
また、第１及び第２センサ部が超音波信号を送受信可能な構成であるため、赤外線センサ等と異なり水滴や汚れの付着によっても誤動作しにくい。また、電磁波（光、赤外線を含む）によるセンサでは水中での信号の減衰が大きいのに対して、超音波は水中でも余り減衰せずに伝搬するため水中での位置検出に適している。更に、第１及び第２センサ部の超音波送信端から出射される超音波の出射ビームの指向性はそれ程鋭くなく、その指向性パターンの半値角は２０〜３０°程度の広がりがある。このため、第２センサ部はその個数が少なくても（例えば、１個であっても）、頭部位置の検出範囲が広く、浴槽水位が変動してもそれより上位の頭部の位置を確実に検出できるのである。
これら超音波の持つ特性より、第２位置検出手段及び第１位置検出手段は夫々高精度の位置検出が可能となるのである。
従って、第２位置検出手段及び第１位置検出手段の検出出力に基づく当該沈水状態が所定時間以上継続した場合等に、判定手段が異状沈水であると判定することで、浴槽内での溺死に至る可能性の高い入浴者の頭部の異状沈水を確実且つ早期に発見することができるのである。
【００１５】
ところで、異状沈水により呼吸が停止すると通常１〜２分後には心臓が停止する。呼吸が停止し脳に酸素が供給されなくなっても、早期に発見し人口呼吸や心臓マッサージを施すことにより蘇生させることができる。沈水時間と蘇生率の関係は、２分で９０％、３分で７５％、４分で５０％、５分で２５％と報告されている。即ち、入浴中に溺れた場合、早期に発見すれば蘇生の可能性が高くなることが分かる。
そこで、上記の特徴構成によれば、判定手段が異状沈水状態であると判定した判定結果に基づいて緊急情報出力手段が緊急情報を出力することにより、その緊急情報を受けた同居人等の第三者が入浴者を早期に救助することができ、呼吸停止に至っていた場合であっても蘇生の可能性が高くなるのである。
【００１６】
また、更なる特徴構成によれば、緊急情報出力手段の有無にかかわらず、入浴者が、入浴者の鼻や口が浴槽の湯水内に沈水した呼吸不能な状態で、長時間にわたり放置されるのを防止できるのである。つまり、浴槽内の湯水が強制的に排水されるため、その水位が低下し、入浴者の鼻や口が沈水状態から開放され、第三者による救助までに呼吸可能な状態に復帰するために、第三者の救助によって蘇生する可能性が飛躍的に向上することが期待されるのである。
【００１７】
また、更なる特徴構成によれば、緊急情報出力手段が出力した緊急情報を受けた第三者がより早期に入浴者を救助できる。また、その際、通常、入浴者をそのままの状態で浴槽外に救出するのが困難であるため、浴槽内の湯水を排水する必要が生じるが、本特徴構成によれば、その手間も省けるので、入浴者の救助が一層迅速に行えるのである。
【００１８】
ここで、第２位置検出手段と第１位置検出手段と判定手段の協動により入浴者の頭部異状沈水を判定することにより上記の作用効果が発揮されることから、これらは一体で構成されていても、或いは、別体で構成されていても構わない。また、第１位置検出手段と第２位置検出手段は、第１または第２センサ部と、前記各センサ部の出力信号より浴槽水面下にある身体または頭部の各位置を検出する信号処理部が、一体で構成されていても、或いは、分離して構成されていても、更に、その信号処理部と判定手段が一体で構成されていても、何れであっても構わない。要するに、第１及び第２センサ部が夫々超音波信号を送受信可能であって上記した所定位置に設置されていればよい。
【００１９】
また、更なる特徴構成によれば、浴槽内の水温の変化によって第１センサ部が送受信する超音波信号の伝搬速度が変動するのを第１温度補正手段が補正するため水温変化にかかわらず入浴者の浴槽水面下にある身体位置の正確な検出ができ、更に、浴室内の気温変化によって第２センサ部が送受信する超音波信号の伝搬速度が変動するのを第２温度補正手段が補正するため気温変化にかかわらず入浴者の頭部位置の正確な検出ができ、浴槽内の水温や浴室内の気温の変動にかかわらず常に上記の特徴構成による作用効果を確実に奏することができるのである。
【００２０】
また、更なる特徴構成によれば、上述の如く、第２センサ部の超音波送信端から出射される超音波の出射ビームの指向性はそれ程鋭くなく、その指向性パターンの半値角は２０〜３０°程度の広がりがあり、通常、出射ビームの中心軸上で出力強度が最大で、中心軸から逸れるに従って出力強度が減衰するため、浴槽水面に入射して散乱する超音波信号は頭部に入射する超音波信号より弱く、また、浴槽水面で反射散乱後は時間的空間的に分散し更に強度が減衰する。従って、第２センサ部で受信される当該信号は、頭部で反射された超音波信号とは区別されうるため、頭部位置の検出がより確実になされるのである。
【００２１】
また、更なる特徴構成によれば、例えば、入浴者自身や同居人等の救助に来た第三者が強制排水を停止する必要があるときに、その強制排水を解除できるのである。
【００２２】
また、更なる特徴構成によれば、浴槽内の湯が完全には排水されないため、下半身が入浴状態のまま維持されるので、入浴により上昇した体温が、再び低下する事態が回避でき、入浴により低下した血圧がその体温の低下に伴って上昇するという血圧の急激な変化も軽減できるのである。従って、強制排水によって溺死を回避するとともに、血圧変動に伴う脳或いは心臓の機能不全に陥る危険性も軽減できるのである。
また、更なる特徴構成によれば、判定手段が最初に入浴者が沈水状態であると判定した場合に警告音または警告メッセージを発生する「警告モード」に入り、さらにその状態が所定時間継続して異常沈水状態にあると判定した場合に緊急情報出力手段に警報信号を送信する「警報モード」に入るので、上記の特徴構成による作用効果を確実に奏することができるのである。
また、更なる特徴構成によれば、判定手段が最初に入浴者が沈水状態であると判定した場合に警告音または警告メッセージを発生する「警告モード」に入り、さらにその状態が所定時間継続して異常沈水状態にあると判定した場合に強制排水手段に強制排水信号を送信する「強制排水モード」に入るので、上記の特徴構成による作用効果を確実に奏することができるのである。
【００２３】
【発明の実施の形態】
本発明に係る浴槽内事故検出装置（以下、本発明装置という。）の実施の形態を図面に基づいて説明する。
【００２４】
図１及び図２に示すように、本発明装置は、浴槽１内にいる入浴者２の浴槽水面下にある身体２ａの位置を検出可能な第１位置検出手段３と、前記入浴者２の頭部２ｂの位置を検出可能な第２位置検出手段４と、前記第１位置検出手段３と前記第２位置検出手段４の両検出出力に基づいて前記頭部２ｂの異状沈水を判定する判定手段５と、前記判定手段５の判定結果に基づいて緊急情報を出力する緊急情報出力手段６と、前記判定手段５の判定結果に基づいて前記浴槽１内の湯水を強制的に排水する強制排水手段７と、前記強制排水手段７の強制排水状態を解除する解除手段８を備えて構成されている。
【００２５】
前記第１位置検出手段３は、前記浴槽１内に超音波信号を一定のサンプリング間隔で送信して、前記浴槽１内の前記入浴者２の浴槽水面下にある身体２ａや前記浴槽１の内壁面等の対象物からの反射信号を受信する第１センサ部３ａと、前記超音波信号の送信から所定閾値以上の受信信号を受信するまでの時間差、即ち前記超音波信号の前記対象物までの往復時間と水中の伝搬定数から前記対象物までの距離Ｌ₁ を算出し、算出した距離Ｌ₁ から前記入浴者２が前記浴槽１内に存在することを確認する第１信号処理部３ｂとから構成されている。
尚、前記サンプリング間隔は５秒に設定されている。また、前記第１センサ部３ａと前記第１信号処理部３ｂは分離して別体で構成されており、前記第１センサ部３ａは、前記浴槽水面下にある身体２ａの位置を検出する必要性から、前記浴槽１の第１内壁面１ａの入浴時における通常水位の下限位置より下方位置に設置されている。この第１内壁面１ａは、前記超音波信号が確実に前記入浴者２まで到達するように、前記入浴者２が前記浴槽１の長手方向に沿って脚を伸ばして入浴した場合、前記入浴者２の足先側或いは背中側に位置している。
【００２６】
前記第２位置検出手段４は、前記浴槽１内の入浴者の頭部に向けて超音波信号を一定のサンプリング間隔で送信して、前記浴槽１内の前記入浴者２の頭部２ａや前記浴槽１の水面１ｃより上方に位置する浴槽内壁面や浴室９の内壁面等の対象物からの反射信号を受信する第２センサ部４ａと、前記超音波信号の送信から所定閾値以上の受信信号を受信するまでの時間差、即ち前記超音波信号の前記対象物までの往復時間と空気中の伝搬定数から前記対象物までの距離Ｌ₂ を算出し、算出した距離Ｌ₂ から前記入浴者２の頭部２ｂが前記水面１ｃより下方に沈水しているか否かを判定する第２信号処理部４ｂとから構成されている。
尚、前記サンプリング間隔は５秒に設定されている。また、前記第２センサ部４ａと前記第２信号処理部４ｂは分離して別体で構成されており、前記第２センサ部４ａは、前記水面２より上方にある前記頭部２ｂの位置を検出する必要性から、前記浴槽１の前記第１内壁面１ａの上側にある前記浴室９の第１浴室内壁面９ａに設置されている。尚、当該設置位置は前記入浴時における前記浴槽１の通常水位の上限位置より上側に位置している。また、前記第２センサ部４ａの設置方向は、前記超音波信号の出射ビームの中心軸が水平になるように設定されている。
【００２７】
前記第１信号処理部３ｂは、前記サンプリング間隔毎に算出した前記対象物までの距離Ｌ₁ が前記第１センサ部３ａとそれと対面する前記浴槽１の第２内壁面１ｂまでの距離Ｌｂに対して許容誤差範囲内（Ｌｂ±５％）であれば、前記浴槽１内の前記入浴者２が存在していないと判定し「非入浴モード」に入る。また、「非入浴モード」において、新たに算出した前記距離Ｌ₁ が、前記距離Ｌｂに対して許容誤差範囲（Ｌｂ±５％）より短い場合には、前記浴槽１内の前記入浴者２が存在していると判定し、「入浴モード」に入るとともに、入浴者検出信号Ｓを前記判定手段５に出力する。この入浴者検出信号Ｓは、前記サンプリング間隔毎に新たに算出した前記距離Ｌ₁ によって「非入浴モード」に入るまで、継続出力される。
【００２８】
前記第２信号処理部４ｂは、前記サンプリング間隔毎に算出した前記対象物までの距離Ｌ₂ が、前記第２センサ部４ａとそれと対面する前記浴室９の第２浴室内壁面９ｂまでの距離或いは前記所定閾値以上の反射信号を反射する固定物があればその固定物までの距離の内の最も短い距離Ｌｗに対して許容誤差範囲（Ｌｗ±５％）より短い場合には、前記第２センサ部４ａから発信した前記超音波信号が前記入浴者２の頭部２ｂで反射した反射信号が受信されたものと判断し、この結果、前記浴槽１内で前記入浴者２の頭部２ｂが前記水面１ｃより下方に沈水していないと判定し「非沈水モード」に入る。
また、図３に示すように、この「非沈水モード」において、新たに算出した前記距離Ｌ₂ が、前記距離Ｌｗに対して許容誤差範囲内（Ｌｗ±５％）であれば、前記浴槽１内で前記入浴者２の頭部２ｂが前記水面１ｃより下方に沈水していると判定し「沈水モード」に入るとともに、沈水検出信号Ｔを前記判定手段５に出力する。この沈水検出信号Ｔは、前記サンプリング間隔毎に新たに算出した前記距離Ｌ₂ によって「非沈水モード」に入るまで、継続出力される。
【００２９】
前記判定手段５は、前記第１信号処理部３ｂから前記入浴者検出信号Ｓを受信している期間中「入浴モード」に入り、その「入浴モード」において、前記第２信号処理部４ｂから前記沈水検出信号Ｔを受信し「沈水モード」に入ると、前記頭部２ｂが前記水面１ｃより下方に沈水している沈水状態であると判定する。前記両信号Ｓ，Ｔの同時受信状態が１０秒間（２サンプリング間隔分）継続すると、「警告モード」に入り、「警告モード」に入ってから、前記両信号Ｓ，Ｔの受信状態が更に１０秒間（合計２０秒間）継続すると、異状沈水状態であると判定し、「警報・強制排水モード」に入り、警報信号Ｗと強制排水信号Ｐを発信するように構成されている。
【００３０】
前記判定手段５は、「警告モード」に入ると、前記浴槽１内に設置された水中スピーカ等の警告発生手段１０から所定の警告音または警告メッセージを発生し、前記入浴者２に対して注意を喚起する。ここで、前記入浴者２に意識があれば、その警告音または警告メッセージを聞いて前記頭部２ｂを持ち上げることにより、次の信号サンプリング後に「非沈水モード」に遷移し、前記沈水検出信号Ｔの出力を停止し、「警告モード」が解除され、「警報・強制排水モード」に入ることはない。前記警告音または警告メッセージは前記入浴者２に対する意識確認手段として機能する。ここで、一旦「警告モード」になった場合は、前記沈水検出信号Ｔの出力が停止しても、上記のように解除されず、解除ボタンの押下等の所定の解除操作で「警告モード」を解除するようにしても構わない。
【００３１】
「警告モード」において、前記入浴者２に異状があれば、前記警告音または警告メッセージを聞いても前記頭部２ｂを持ち上げる等の解除操作を行わないため、「警告モード」が解除されずに「警報・強制排水モード」に入る。
【００３２】
ところで、前記第１及び第２信号処理部３ｂ，４ｂと前記判定手段５は同じ電子回路内に構成する方が、信号処理上便利である。本実施形態では、前記第１及び第２信号処理部３ｂ，４ｂと前記判定手段５を一体で信号処理部１１として形成し、前記第１及び第２センサ部３ａ，４ａと分離した構成としている。また、この信号処理部１１は浴室壁面等に取り付け可能な構造となっている。
【００３３】
前記緊急情報出力手段６は、「警報・強制排水モード」に入り、前記警報信号Ｗを受信すると、スピーカ等の所定の出力装置１２から警報音または警報メッセージを発生させる。前記出力装置１２は浴室外の同居人等の第三者がいる部屋や廊下等に設置されている。ここで、前記出力装置１２の設置箇所が浴室から遠く離れている場合は、有線或いは無線の通信手段を介して、前記緊急情報出力手段６と前記出力装置１２を接続するようにしても構わない。例えば、前記出力装置１２は携帯電話端末等の携帯型の装置であってもよい。また、前記入浴者２が独居人である場合は、前記出力装置１２はセキュリティ会社や病院等の外部機関に設置して、前記緊急情報出力手段６と電話回線等を介して接続し、これらの外部機関に当該警報音または警報メッセージを通報できるようにしても構わない。
【００３４】
前記強制排水手段７は、前記判定手段５から有線或いは無線の通信手段を介して前記強制排水信号Ｐを受信する受信部７ａと、前記浴槽１内の湯水を前記浴槽１外に強制排出する排水部７ｂから構成されており、また、前記浴槽１の壁面に取り付け可能な構造となっている。
前記排水部７ｂは、前記強制排水信号Ｐを受信するとモータポンプを作動させて、前記浴槽１内の湯水を汲み上げて洗い場等の前記浴槽１外に排水する。前記排水部７ｂの電源は、所定の内蔵電池であっても、商用電源からの電力供給であっても構わない。また、前記排水部７ｂの排水能力は、溺死寸前の患者の蘇生率が上述の如く４分以上で５０％以下に低下するため、遅くとも４分以内に沈水した鼻や口が離水するように設定しなければならない。このため、前記モータポンプは前記浴槽１の湯水を満水状態から半分の貯水状態にまで遅くとも４分で排水できるものを使用する。例えば、前記浴槽１の満水容量が２８０リットルの場合は、前記モータポンプの排水能力は３５リットル／分以上が望ましい。尚、この値は一例であって、前記モータポンプの排水能力は前記浴槽１の満水容量や形状等を考慮して適宜変更するものとする。
【００３５】
ところで、前記強制排水手段７には、前記入浴者２に異状が無かったにもかかわらず、「警告モード」における前記警告音または警告メッセージが聞こえず「警報・強制排水モード」に入り、前記浴槽１の湯水の強制排水が開始された場合に、前記入浴者２や救助者が当該強制排水を解除できる前記解除手段８が設けられてある。具体的には、前記排水部７ｂの作動を強制停止する解除ボタン７ｃが前記強制排水手段７の前記入浴者２が操作容易な位置に設けられている。
【００３６】
「警報・強制排水モード」が解除されずに進行すると、前記浴槽１内の水位は低下し、やがて前記第１センサ部３ａが水中から空気中に露出すると、前記超音波信号は水中より音速が４倍以上遅い空気中を伝搬することになるため、前記対象物までの距離Ｌ₁ が見かけ上長くなり、急激に変化する。
従って、前記入浴者２が前記浴槽１内にいるにもかかわらず、前記距離Ｌ₁ が前記許容誤差範囲（Ｌｂ±５％）より長くなり、「非入浴モード」と判定する場合もあり得る。そこで、まだ、前記浴槽１内の湯水を排水する必要がある場合では、前記第１信号処理部３ｂが「非入浴モード」に復帰して前記入浴者検出信号Ｓの出力を停止するのを、前記距離Ｌ₁ の急激な変化を検出することにより抑制するか、或いは、前記強制排水は前記解除手段８でのみ解除される構成としてる。
【００３７】
しかし、前記第１センサ部３ａが前記浴槽１内の底面に近い低位置に設置されている場合であって、当該位置より浅い水深まで排水されれば、もはや前記頭部２ｂが沈水から開放される状況にある場合は、前記第１信号処理部３ｂは、この距離Ｌ₁ の急激な変化を検出するか、前記距離Ｌ₁ が前記許容誤差範囲（Ｌｂ±５％）を超えたことを検出すれば、前記浴槽１内の湯水が前記頭部２ｂが沈水から開放される水位まで排水したと判定して、「入浴モード」から「非入浴モード」に復帰し、前記入浴者検出信号Ｓの出力を停止するようにしても構わない。尚、前記排水部７ｂの取水口の高さを前記第１センサ部３ａと同様に低位置に設定することでも、自動的に同様の効果を得ることができる。
【００３８】
前記判定手段５は、前記入浴者検出信号Ｓの出力を停止とともに、前記強制排水信号Ｐの発信を停止し、「警報・強制排水モード」から「警報モード」に移行する。前記強制排水手段７は前記強制排水信号Ｐの受信停止により、前記解除手段により前記強制排水を自動解除する。この時点で、救助者或いは前記入浴者２自身が前記信号処理部１１に設けられた解除ボタンの押下等の所定の解除操作で「警報モード」が解除されていない限り、前記警報音または警報メッセージの通報は継続する。
【００３９】
以下に別実施形態を説明する。
〈１〉上記実施の形態に対して、前記第１位置検出手段３が、前記浴槽１内の水温を検出して前記第１センサ部３ａが送受信する超音波信号の伝搬速度を補正する第１温度補正手段を備え、更に、前記第２位置検出手段４は前記第２センサ部４ａの周囲の気温を検出して前記第２センサ部４ａが送受信する超音波信号の伝搬速度を補正する第２温度補正手段を備えるようにするもの好ましい実施の形態である。
この場合、前記距離Ｌ₁ と前記距離Ｌ₂ の算出は、基本的には、夫々の超音波信号の反射時間（往復の伝搬時間の半分）に夫々の超音波信号の伝搬速度を乗算して求まるが、夫々の水中及び空気中での伝搬速度は温度が高くなるほど速くなる。
空気中では１℃上昇すると約０．６０７ｍ／ｓ速くなるので、気温Ｔの変化に対する伝搬速度ｖの変化を１次式で近似して、数１に示す近似式に基づいて前記第２温度補正手段が伝搬速度を補正することができる。
【００４０】
【数１】
ｖ＝３３１．５＋０．６０７Ｔ（ｍ／ｓ）
【００４１】
水中の場合は、水温変化に対する伝搬速度の変化を１次式で精度良く近似できないため、前記第１温度補正手段が予め水温と伝搬速度の関係を所定温度間隔でテーブル化して記憶しておくことで、伝搬速度の補正をすることができる。尚、前記浴槽１内の前記第１センサ部３ａの水深は精々数１０ｃｍ程度であるので、浴槽水位の変動による水圧の影響は無視できる。
【００４２】
〈２〉上記実施の形態では、前記第１及び第２信号処理部３ｂ，４ｂは夫々前記距離Ｌ₁ と前記距離Ｌ₂ を算出していたが、前記距離Ｌ₁ と前記距離Ｌ₂ の算出に用いた反射時間を、夫々（Ｌｂ±５％）及び（Ｌｗ±５％）に相当する超音波の伝搬時間とを比較して、各判定を行うようにしても構わない。
【００４３】
〈３〉上記実施の形態では、前記第１及び第２位置検出手段３，４、前記第１センサ部３ａと前記第１信号処理部３ｂ、前記第２センサ部４ａと前記第２信号処理部４ｂが、夫々分離して別体で構成されており、前記第１及び第２信号処理部３ｂ，４ｂと前記判定手段５を一体で信号処理部１１として形成しているが、これらの構成は必ずしも上記実施の形態に限定されるものではない。例えば、前記第１及び第２信号処理部３ｂ，４ｂと前記判定手段５を分離し、前記第１センサ部３ａと前記第１信号処理部３ｂ、前記第２センサ部４ａと前記第２信号処理部４ｂを、夫々一体で構成しても構わない。また、前記距離Ｌ₁ や前記距離Ｌ₂ の演算処理や比較判定を、前記第１及び第２信号処理部３ｂ，４ｂで行わずに、前記判定手段５で行うようにしても構わない。
【００４４】
〈４〉「警告モード」や「警報・強制排水モード」に入るタイミング、及び、その他のタイミングや許容誤差範囲の設定は、上記実施の形態に限定されるものではなく、適宜変更可能である。
また、「警告モード」は必ずしも設ける必要はなく、直接「警報・強制排水モード」に入るように構成されていても構わない。この場合、前記警告発生手段１０は不要である。
【００４５】
〈５〉前記強制排水手段７は必ずしも前記モータポンプで湯水を汲み上げる構成でなくても構わない。例えば、前記浴槽１の排水口の止水を電磁弁で制御するようにして、前記強制排水手段７が前記強制排水信号Ｐを受信すると前記電磁弁を作動させて前記排水口を開成するようにしても構わない。また、電磁弁を設けた強制排水専用の排水口を前記浴槽１に設けても構わない。更に、前記強制排水手段７が前記強制排水信号Ｐを受信すると排水口の栓をワイヤー等で機械的に引き抜く手段を設けても構わない。
【００４６】
〈６〉「警告モード」や「警報・強制排水モード」において、前記警告音または警告メッセージ、或いは、前記警報音または警報メッセージを発生する代わりに、光の点滅や振動等の他の出力手段を用いて、警告や警報を発生しても構わない。
【００４７】
〈７〉上記実施の形態では、本発明装置は、既設の浴槽に後から装着できる形態のものを示したが、新規に浴槽を設置する場合は、本発明装置を予め内蔵した浴槽を使用しても構わない。
【００４８】
〈８〉前記強制排水手段７の強制解除状態を解除する解除手段は必ずしも前記強制排水手段７に設けなくても構わない。
例えば、前記判定手段５に「警報・強制排水モード」を強制解除する解除ボタン等を設け、「警報・強制排水モード」の解除と同時に前記強制排水信号Ｐの発信を停止するようにし、前記強制排水手段７は、前記強制排水信号Ｐの受信の停止と同時に当該強制排水を停止するように構成しても構わない。
【図面の簡単な説明】
【図１】本発明に係る浴槽内事故検出装置の構成を示す説明図
【図２】本発明に係る浴槽内事故検出装置の設置状態を示す斜視図
【図３】入浴者の頭部が沈水状態にある状況を説明する説明図
【符号の説明】
１浴槽
１ａ第１内壁面
１ｂ第２内壁面
１ｃ水面
２入浴者
２ａ身体
２ｂ頭部
３第１位置検出手段
３ａ第１センサ部
３ｂ第１信号処理部
４第２位置検出手段
４ａ第２センサ部
４ｂ第２信号処理部
５判定手段
６緊急情報出力手段
７強制排水手段
７ａ受信部
７ｂ排水部
７ｃ解除ボタン
８解除手段
９浴室
９ａ第１浴室内壁面
９ｂ第２浴室内壁面
１０警告発生手段
１１信号処理部
１２出力装置
Ｓ入浴者検出信号
Ｔ沈水検出信号
Ｐ強制排水信号
Ｗ警報信号[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an in-tub accident detection device that can detect abnormal submergence of a head due to an abnormal condition of a bather in a bathtub at an early stage and prevent an accident due to the abnormal submergence.
[0002]
[Prior art]
The most common cause of accidental death at home is drowning in the bath tub. Death during bathing is classified into drowning, which is an accidental death as described above, and morbidity that occurred during bathing such as heart disease. The total number of deaths from bathing is about 10,000 people every year, and the number of deaths is comparable to death from traffic accidents. In particular, many elderly people die from bathing, which is a big problem. Bathing deaths occur frequently in winter, and are caused by the magnitude of blood pressure fluctuations associated with bathing.
In particular, as an action with high risk during bathing, it is an action to stand up from a bathtub so as to get out of the bathtub. When immersed in a bathtub, the peripheral blood vessels expand due to the thermal effect, blood circulation is improved, and blood pressure is reduced. Furthermore, when the patient stands up in that state, the blood moves downward due to the influence of gravity, so that the brain and the heart fall into an ischemic state, thereby increasing the possibility of causing brain disease and heart disease. Even a healthy person may cause symptoms such as dizziness when getting out of the bathtub. If you lose consciousness in the bathtub, it often falls into the bathtub and leads to drowning. Even if it falls in the bathtub, it may be avoided that the head and shoulders are caught on the edge of the bathtub and the like and drowned. When investigating the case of drowning in the bathtub, it is often the case that the lengthwise dimension is short and deep, and the Japanese style bathtub is prone and drowned, and the long lengthwise dimension is shallow and drowned on the back. While death or accidental death may occur in the washing area, death in the bathroom is overwhelmingly death in the bathtub.
[0003]
Then, the abnormality detection apparatus for discovering this accident in a bathtub early, and the bathroom safety apparatus for preventing the said accident further are proposed. For example, as an abnormality detection apparatus, there is an abnormality detection apparatus for a bathroom disclosed in JP-A-8-50693. Moreover, there exists a bathroom safety apparatus currently disclosed by Unexamined-Japanese-Patent No. 8-66323 as a bathroom safety apparatus.
This conventional abnormality detection device has a large number of human body detection sensors (infrared sensors, optical sensors, etc.) arranged in the bathroom around the bathtub, etc., and operates when each human body detection sensor detects a human body, and all human body detection sensors operate. An anomaly is detected by analyzing the pattern. For example, in the case of falling down in a washing place, a large number of human body detection sensors installed at low positions on the wall surface around the washing place are operated for a long time, and the abnormality is detected by analyzing the operation pattern. When a bather stops moving in the bathtub, a large number of human body detection sensors installed around the bathtub or in the upper part of the bathtub are operated for a long time to detect the abnormality by analyzing the operation pattern.
In addition, the conventional bathroom safety device has a water level detecting means for detecting the water level of the bathtub, and a plurality of light emitting elements and light receiving elements arranged so as to detect the position of the bather's head on the inner surface of the bathtub. A detection means that compares the position of the bather's head with the water level to determine whether the head is submerged in the water. The water is forcibly drained, and the bathroom is heated.
[0004]
[Problems to be solved by the invention]
However, the conventional abnormality detection device is a large-scale system for a new bathroom such as a hotel or an elderly center, and has a problem that it cannot be installed in an existing bathroom at home. Moreover, in order to improve the detection accuracy, a large number of human body detection sensors must be arranged in the bathroom, resulting in a problem that the device cost increases.
Also, in the conventional bathroom safety device, since the bathtub water level fluctuates, it is necessary to provide a large number of position detecting means. In addition, a light receiving element that receives a narrow beam of a predetermined wavelength such as an infrared sensor may cause a light receiving operation failure due to adhesion of water droplets or dirt.For example, if a light receiving element above the water surface has a light receiving operation failure, the head position is There is a risk of erroneous detection and misjudging whether the head is submerged in water.
[0005]
The present invention has been made in view of the above-mentioned problems, and its purpose is to detect an accident in a bathtub that can reliably detect abnormal submergence of the head of a bather who is likely to be drowned in the bathtub. The present invention provides a device, and further provides an in-tub accident detection device that can rescue such bathers at an early stage.
[0006]
[Means for Solving the Problems]
In order to achieve this object, the first characteristic configuration of the in-tub accident detection device according to the present invention is as described in claim 1 in the section of the claims. First position detecting means capable of detecting a position of a body, second position detecting means capable of detecting the position of the bather's head, both detection of the first position detecting means and the second position detecting means Based on the determination result of the abnormal determination submersion of the head based on the output, and the determination result of the determination means Forced drain means for forcibly draining hot water in the bathtub, and release means for releasing the forced drain state of the forced drain means The first position detecting means includes a first sensor unit that is capable of transmitting an ultrasonic signal to an object facing and receiving an ultrasonic signal reflected by the object. The lower position of the normal water level at the time of bathing is measured, the distance to the object is measured, the presence of the bather in the bathtub is detected when the distance is shorter than a predetermined value, and the second position detection The means includes a second sensor unit capable of transmitting an ultrasonic signal to the object facing and receiving an ultrasonic signal reflected by the object at a position higher than the upper limit of the normal water level, up to the object. , And detecting that the bather's head is submerged by the distance being within an allowable error range with respect to a predetermined value, and the determining means includes the first position detecting means In the bathtub When the presence of the entry bather is detected and the second position detecting means detects that the bather's head is submerged and the state continues for a predetermined time, the bather Is determined to be abnormally submerged, Forced drainage signal to the forced drainage means Output against Then, after the forced drainage by the forced drainage means is started, the determination means is released from the abnormal submerged state by the first position detection means detecting that the distance to the object is apparently long. When it is determined that the forced drainage state is released by the release means In the point.
[0007]
In addition, the normal water level at the time of bathing is a normal water level during bathing in a state where hot water is supplied for bathing in the bathtub. For the purpose of the present invention, the lower limit means a water level at which the head reaches a water depth that allows the water to sink. However, if the water depth is shallower than the lower limit, the water level is not guaranteed to prevent the head from sinking. In addition, the lower limit of the normal water level naturally varies depending on the shape and size of the bathtub.
[0009]
same second The characteristic configuration of the Claim 2 As described above, first In addition to the above characteristic configuration, there is an emergency information output means for outputting emergency information based on the determination result of the determination means.
[0010]
same Third The characteristic configuration of the Claim 3 As described above, First or second In addition to the characteristic configuration, the first position detecting means includes first temperature correcting means for detecting a water temperature in the bathtub and correcting a propagation speed of an ultrasonic signal transmitted and received by the first sensor unit, The two-position detection means is provided with second temperature correction means for detecting the ambient temperature around the second sensor unit and correcting the propagation speed of the ultrasonic signal transmitted and received by the second sensor unit.
[0011]
same Fourth The characteristic configuration of the Claim 4 As described above, Any one of the first to third In addition to the above-described characteristic configuration, the second sensor unit is installed such that the central axis of the outgoing beam of ultrasonic waves is horizontal.
[0013]
same Fifth The characteristic configuration of the Claim 5 As described above, first In addition to the feature configuration ,in front The determination means generates a predetermined warning sound or warning message first when it is determined that the bather is in a submerged state, and starts forced draining when the submerged state continues for a predetermined time. The point is to send a forced drainage signal to the forced drainage means.
[0014]
The operation and effect will be described below.
The present invention of According to the characteristic configuration, first, since the first sensor part of the first position detection means is installed below the water surface in the bathtub, the position of the body under the bath water surface of the bather, for example, the torso and limbs, The presence of the bather can be confirmed from the position, and since the second sensor part of the second position detection means is installed on the bathtub water surface, the position of the head on the bathtub water surface can be detected. In other words, if the head position detected by the second position detection means is outside the range where the bather's head is present or cannot be detected, the bather's head is submerged below the bath water surface. If the first position detection means confirms the presence of the bather, it is determined that the bather's head is submerged below the surface of the bathtub.
In addition, since the first and second sensor units are configured to transmit and receive ultrasonic signals, unlike an infrared sensor or the like, malfunctions are less likely to occur due to water droplets or dirt. In addition, in the sensor using electromagnetic waves (including light and infrared rays), the attenuation of the signal in water is large. On the other hand, since the ultrasonic wave propagates in water without being attenuated much, it is suitable for position detection in water. Furthermore, the directivity of the outgoing beam of ultrasonic waves emitted from the ultrasonic transmission ends of the first and second sensor units is not so sharp, and the half-value angle of the directivity pattern has a spread of about 20 to 30 °. For this reason, even if the number of the second sensor units is small (for example, one), the detection range of the head position is wide, and even if the bathtub water level fluctuates, the position of the upper head can be determined. It can be detected reliably.
Due to the characteristics of these ultrasonic waves, the second position detection means and the first position detection means can detect positions with high accuracy.
Therefore, when the submergence state based on the detection output of the second position detection unit and the first position detection unit continues for a predetermined time or more, the determination unit determines that the submergence is abnormal, thereby drowning in the bathtub. The abnormal submersion of the bather's head, which is likely to reach, can be detected reliably and early.
[0015]
By the way, when breathing stops due to abnormal submergence, the heart usually stops after 1 to 2 minutes. Even if breathing stops and oxygen is not supplied to the brain, it can be revived by early detection and artificial respiration or cardiac massage. The relationship between submergence time and resuscitation rate is reported as 90% at 2 minutes, 75% at 3 minutes, 50% at 4 minutes, and 25% at 5 minutes. That is, when drowning during bathing, it is understood that the possibility of resuscitation increases if detected early.
Therefore, above According to the characteristic configuration, the emergency information output means outputs emergency information based on the determination result determined that the determination means is in an abnormal submerged state, so that a third party such as a living person who has received the emergency information bathes. The person can be rescued at an early stage, and the possibility of resuscitation is increased even if breathing has stopped.
[0016]
Also, even more According to the characteristic configuration, the bather can be prevented from being left unattended for a long time in a non-breathable state where the bather's nose and mouth are submerged in the hot water of the bathtub regardless of the presence or absence of emergency information output means. It is. In other words, because the hot water in the bathtub is forcibly drained, the water level is lowered, the bather's nose and mouth are released from the submerged state, and return to a breathable state before being rescued by a third party. It is expected that the possibility of resuscitation by the rescue of a third party will be dramatically improved.
[0017]
Also more According to the characteristic configuration, the third party who has received the emergency information output by the emergency information output means can rescue the bather earlier. At that time, it is usually difficult to rescue the bather out of the bathtub as it is, so it is necessary to drain the hot water in the bathtub. The bather can be rescued more quickly.
[0018]
Here, since the above-described effect is exhibited by determining the abnormal water submergence of the bather by the cooperation of the second position detecting means, the first position detecting means, and the determining means, these are configured integrally. Or may be configured as a separate body. The first position detection means and the second position detection means include a first or second sensor unit and a signal processing unit that detects each position of the body or head below the bath water surface from the output signal of each sensor unit. However, the signal processing unit and the determination unit may be integrated, or may be configured separately. In short, it is only necessary that the first and second sensor units can transmit and receive an ultrasonic signal and are installed at the predetermined positions.
[0019]
Also more According to the characteristic configuration, since the first temperature correction means corrects the propagation speed of the ultrasonic signal transmitted and received by the first sensor unit due to the change in the water temperature in the bathtub, the bath water surface of the bather regardless of the change in the water temperature. It is possible to accurately detect the position of the underlying body, and further, the second temperature correction means corrects the change in the propagation speed of the ultrasonic signal transmitted and received by the second sensor unit due to the temperature change in the bathroom. Regardless of whether the bather's head position can be detected accurately, the water temperature in the bathtub or the temperature in the bathroom is always above The effect by the characteristic configuration can be surely exhibited.
[0020]
Also more According to the characteristic configuration, as described above, the directivity of the outgoing beam of the ultrasonic wave emitted from the ultrasonic transmission end of the second sensor unit is not so sharp, and the half-value angle of the directivity pattern is about 20 to 30 °. There is a spread, and the output intensity is usually maximum on the central axis of the outgoing beam, and the output intensity attenuates as it deviates from the central axis. It is weaker than the signal, and after being reflected and scattered on the water surface of the bathtub, it is dispersed in time and space, and the intensity is further attenuated. Accordingly, since the signal received by the second sensor unit can be distinguished from the ultrasonic signal reflected by the head, the position of the head is more reliably detected.
[0021]
Also more According to the characteristic configuration, for example, when a third party who has come to the rescue, such as a bather or a living person, needs to stop forced drainage, the forced drainage can be canceled.
[0022]
Also more According to the characteristic configuration, since the hot water in the bathtub is not completely drained, the lower body is maintained in a bathing state, so that the temperature that has risen due to bathing can be avoided again, and the blood pressure that has decreased due to bathing can be avoided. The rapid change in blood pressure that rises as the body temperature decreases can also be reduced. Therefore, drowning can be avoided by forced drainage, and the risk of dysfunction of the brain or heart associated with blood pressure fluctuations can be reduced.
Also more According to the characteristic configuration, when the determination means first determines that the bather is in a submerged state, it enters a “warning mode” that generates a warning sound or a warning message, and the state continues for a predetermined time and is in an abnormal submerged state. When entering the "alarm mode" that sends an alarm signal to the emergency information output means when it is determined that above The effect by the characteristic configuration can be surely exhibited.
Also more According to the characteristic configuration, when the determination means first determines that the bather is in a submerged state, it enters a “warning mode” that generates a warning sound or a warning message, and the state continues for a predetermined time and is in an abnormal submerged state. If you decide to be in the `` forced drainage mode '' that sends a forced drainage signal to the forced drainage means, above The effect by the characteristic configuration can be surely exhibited.
[0023]
DETAILED DESCRIPTION OF THE INVENTION
An embodiment of an in-tub accident detection apparatus (hereinafter referred to as the present invention apparatus) according to the present invention will be described with reference to the drawings.
[0024]
As shown in FIGS. 1 and 2, the device of the present invention includes a first position detection means 3 capable of detecting the position of a body 2 a under the bath water surface of a bather 2 in the bathtub 1, and the bather 2. The second position detection means 4 capable of detecting the position of the head 2b, and the determination for determining abnormal water subsidence of the head 2b based on both detection outputs of the first position detection means 3 and the second position detection means 4. Means 5, emergency information output means 6 for outputting emergency information based on the determination result of the determination means 5, and forced drainage for forcibly draining hot water in the bathtub 1 based on the determination result of the determination means 5 Means 7 and release means 8 for releasing the forced drainage state of the forced drainage means 7 are provided.
[0025]
The first position detection means 3 transmits an ultrasonic signal into the bathtub 1 at a constant sampling interval, and the body 2a under the bath water surface of the bather 2 in the bathtub 1 or the inside of the bathtub 1 The first sensor unit 3a that receives a reflection signal from an object such as a wall surface, and the time difference from the transmission of the ultrasonic signal to the reception of a reception signal that exceeds a predetermined threshold, that is, the ultrasonic signal to the object Distance L from the round-trip time and underwater propagation constant to the object ₁ And the calculated distance L ₁ From the first signal processing unit 3b for confirming that the bather 2 is present in the bathtub 1.
The sampling interval is set to 5 seconds. In addition, the first sensor unit 3a and the first signal processing unit 3b are separated and configured separately, and the first sensor unit 3a needs to detect the position of the body 2a under the bathtub water surface. From the nature, it is installed at a position below the lower limit position of the normal water level when bathing the first inner wall surface 1a of the bathtub 1. When the bather 2 bathes with the legs extending along the longitudinal direction of the bathtub 1 so that the ultrasonic signal reliably reaches the bather 2, the first inner wall surface 1 a 2 is located on the toe side or back side.
[0026]
The second position detection means 4 transmits an ultrasonic signal to the bather's head in the bathtub 1 at a constant sampling interval, and the head 2a of the bather 2 in the bathtub 1 and the A second sensor unit 4a that receives a reflected signal from an object such as an inner wall surface of the bathtub or an inner wall surface of the bathroom 9 that is located above the water surface 1c of the bathtub 1, and a received signal that is equal to or greater than a predetermined threshold from the transmission of the ultrasonic signal. , That is, the distance L to the object from the round-trip time of the ultrasonic signal to the object and the propagation constant in the air. ₂ And the calculated distance L ₂ The second signal processing unit 4b for determining whether or not the head 2b of the bather 2 is submerged below the water surface 1c.
The sampling interval is set to 5 seconds. Further, the second sensor unit 4a and the second signal processing unit 4b are separated and configured separately, and the second sensor unit 4a determines the position of the head 2b above the water surface 2. From the need to detect, it is installed on the first bathroom inner wall surface 9 a of the bathroom 9 above the first inner wall surface 1 a of the bathtub 1. In addition, the said installation position is located above the upper limit position of the normal water level of the said bathtub 1 at the time of the said bathing. The installation direction of the second sensor unit 4a is set so that the central axis of the outgoing beam of the ultrasonic signal is horizontal.
[0027]
The first signal processing unit 3b is configured to calculate the distance L to the object calculated at each sampling interval. ₁ Is within an allowable error range (Lb ± 5%) with respect to the distance Lb from the first sensor portion 3a to the second inner wall surface 1b of the bathtub 1 facing the first sensor portion 3a, the bather 2 in the bathtub 1 Enter the "non-bathing mode". In the “non-bathing mode”, the newly calculated distance L ₁ However, when the distance Lb is shorter than the permissible error range (Lb ± 5%), it is determined that the bather 2 exists in the bathtub 1 and enters the “bathing mode”. A person detection signal S is output to the determination means 5. This bather detection signal S is the distance L newly calculated at each sampling interval. ₁ Is continuously output until the “non-bathing mode” is entered.
[0028]
The second signal processing unit 4b is configured to calculate a distance L to the object calculated at each sampling interval. ₂ However, if there is a fixed object that reflects a reflected signal that is equal to or greater than the predetermined threshold, the distance from the second sensor unit 4a to the second bathroom inner wall surface 9b of the bathroom 9 that faces the second sensor unit 4a is within the distance to the fixed object. When the shortest distance Lw is shorter than the allowable error range (Lw ± 5%), the reflected signal reflected by the head 2b of the bather 2 is reflected by the ultrasonic signal transmitted from the second sensor unit 4a. As a result, it is determined that the head 2b of the bather 2 has not submerged below the water surface 1c in the bathtub 1, and the "non-submergence mode" is entered.
Further, as shown in FIG. 3, in the “non-submersion mode”, the newly calculated distance L ₂ However, if it is within an allowable error range (Lw ± 5%) with respect to the distance Lw, it is determined that the head 2b of the bather 2 is submerged below the water surface 1c in the bathtub 1. While entering the “submergence mode”, the submergence detection signal T is output to the determination means 5. This subsidence detection signal T is calculated based on the distance L newly calculated at each sampling interval. ₂ Is continuously output until “non-submersion mode” is entered.
[0029]
The determination means 5 enters the “bathing mode” during the period when the bather detection signal S is received from the first signal processing unit 3b. In the “bathing mode”, the determination unit 5 receives the bathing mode from the second signal processing unit 4b. When the submergence detection signal T is received and “submergence mode” is entered, it is determined that the head 2b is submerged below the water surface 1c. When the simultaneous reception state of both signals S and T continues for 10 seconds (for two sampling intervals), the “warning mode” is entered, and after entering the “warning mode”, the reception state of both signals S and T is further 10 If it continues for 2 seconds (20 seconds in total), it is determined that it is in an abnormal submerged state, enters the “alarm / forced drainage mode”, and transmits an alarm signal W and a forced drainage signal P.
[0030]
When the determination means 5 enters the “warning mode”, a warning sound or warning message is generated from the warning generation means 10 such as an underwater speaker installed in the bathtub 1, and attention is paid to the bather 2. Arouse. Here, if the bather 2 is conscious, by listening to the warning sound or warning message and lifting the head 2b, after the next signal sampling, the mode changes to the “non-submergence mode” and the submergence detection signal T The “warning mode” is canceled and the “alarm / forced drainage mode” is not entered. The warning sound or warning message functions as a consciousness confirmation means for the bather 2. Here, once the “warning mode” is entered, even if the output of the water subsidence detection signal T is stopped, it is not released as described above, and the “warning mode” is performed by a predetermined release operation such as pressing the release button. May be canceled.
[0031]
In the “warning mode”, if there is an abnormality in the bather 2, even if the warning sound or the warning message is heard, the releasing operation such as lifting the head 2 b is not performed, so the “warning mode” is not released. Enter "alarm / forced drainage mode".
[0032]
By the way, it is more convenient in terms of signal processing that the first and second signal processing units 3b and 4b and the determination means 5 are configured in the same electronic circuit. In the present embodiment, the first and second signal processing units 3b and 4b and the determination unit 5 are integrally formed as the signal processing unit 11 and separated from the first and second sensor units 3a and 4a. . Further, the signal processing unit 11 has a structure that can be attached to a bathroom wall surface or the like.
[0033]
When the emergency information output means 6 enters the “alarm / forced drainage mode” and receives the alarm signal W, it generates an alarm sound or an alarm message from a predetermined output device 12 such as a speaker. The output device 12 is installed in a room or hallway where a third party such as a person living outside the bathroom is present. Here, when the installation location of the output device 12 is far from the bathroom, the emergency information output means 6 and the output device 12 may be connected via a wired or wireless communication means. . For example, the output device 12 may be a portable device such as a mobile phone terminal. When the bather 2 is a single person, the output device 12 is installed in an external organization such as a security company or a hospital and connected to the emergency information output means 6 via a telephone line or the like. You may enable it to report the said warning sound or warning message to an external organization.
[0034]
The forced drain means 7 receives the forced drain signal P from the determination means 5 via a wired or wireless communication means, and drains forcibly discharges hot water in the bathtub 1 to the outside of the bathtub 1. It is comprised from the part 7b, and has a structure which can be attached to the wall surface of the bathtub 1.
When the forced drainage signal P is received, the drainage unit 7b operates a motor pump to pump up hot water in the bathtub 1 and drain it out of the bathtub 1 such as a washing place. The power source of the drainage unit 7b may be a predetermined built-in battery or power supply from a commercial power source. In addition, the drainage capacity of the drainage section 7b is set so that the nose and mouth that have submerged within 4 minutes at the latest will be released because the resuscitation rate of a patient who is about to die is reduced to 50% or less after 4 minutes as described above. Must. For this reason, the said motor pump uses what can drain the hot water of the said bathtub 1 from a full water state to a half water storage state in 4 minutes at the latest. For example, when the full capacity of the bathtub 1 is 280 liters, the drainage capacity of the motor pump is desirably 35 liters / minute or more. This value is an example, and the drainage capacity of the motor pump is appropriately changed in consideration of the full water capacity and shape of the bathtub 1.
[0035]
By the way, the forced drainage means 7 enters the “alarm / forced drainage mode” without hearing the warning sound or the warning message in the “warning mode” even though the bather 2 has no abnormality. When the forced drainage of 1 hot water is started, the release means 8 is provided so that the bather 2 or the rescuer can release the forced drainage. Specifically, a release button 7c for forcibly stopping the operation of the drainage portion 7b is provided at a position where the bather 2 of the forced drainage means 7 can easily operate.
[0036]
When the “alarm / forced drainage mode” is proceeded without being canceled, the water level in the bathtub 1 decreases, and when the first sensor unit 3a is exposed from the water to the air, the ultrasonic signal has a speed of sound higher than the water. Because it propagates in the air four times slower, the distance L to the object ₁ Appears to be long and changes rapidly.
Therefore, even though the bather 2 is in the bathtub 1, the distance L ₁ May become longer than the allowable error range (Lb ± 5%), and the “non-bath mode” may be determined. Therefore, when it is still necessary to drain the hot water in the bathtub 1, the first signal processing unit 3b returns to the “non-bathing mode” and stops outputting the bather detection signal S. The distance L ₁ In other words, the forced drainage is canceled only by the canceling means 8.
[0037]
However, if the first sensor unit 3a is installed at a low position close to the bottom surface in the bathtub 1, and if the water is drained to a depth shallower than the position, the head 2b is no longer released from submersion. The first signal processing unit 3b determines that the distance L ₁ Detecting a sudden change in the distance L ₁ Is detected to have exceeded the permissible error range (Lb ± 5%), it is determined that the hot water in the bathtub 1 has drained to a water level at which the head 2b is released from being submerged. May return to the “non-bathing mode” and stop the output of the bather detection signal S. In addition, the same effect can be automatically acquired also by setting the height of the water intake of the said waste_water | drain part 7b to a low position similarly to the said 1st sensor part 3a.
[0038]
The determination means 5 stops the output of the bather detection signal S, stops the transmission of the forced drainage signal P, and shifts from the “alarm / forced drainage mode” to the “alarm mode”. The forced drainage means 7 automatically cancels the forced drainage by the canceling means when reception of the forced drainage signal P is stopped. At this time, unless the “alarm mode” is released by a predetermined release operation such as pressing a release button provided in the signal processing unit 11 by the rescuer or the bather 2 itself, the alarm sound or the warning message The report will continue.
[0039]
Another embodiment will be described below.
<1> In the first embodiment, the first position detection unit 3 detects the water temperature in the bathtub 1 and corrects the propagation speed of the ultrasonic signal transmitted and received by the first sensor unit 3a. Temperature correction means, and the second position detection means 4 detects the temperature around the second sensor unit 4a and corrects the propagation speed of the ultrasonic signal transmitted and received by the second sensor unit 4a. A preferred embodiment is provided with a temperature correction means.
In this case, the distance L ₁ And the distance L ₂ The calculation of is basically obtained by multiplying the reflection time of each ultrasonic signal (half of the round-trip propagation time) by the propagation speed of each ultrasonic signal, but the propagation in each water and air The speed increases with increasing temperature.
When the temperature rises by 1 ° C. in air, the speed is increased by about 0.607 m / s. Therefore, the change in the propagation velocity v with respect to the change in the temperature T is approximated by a linear expression, and the second temperature correction is performed based on the approximate expression shown in Equation 1. Means can correct the propagation velocity.
[0040]
[Expression 1]
v = 331.5 + 0.607T (m / s)
[0041]
In the case of underwater, since the change in propagation speed with respect to the change in water temperature cannot be accurately approximated by a linear expression, the first temperature correction means stores the relationship between the water temperature and the propagation speed in a table at predetermined temperature intervals in advance. Thus, the propagation speed can be corrected. In addition, since the water depth of the said 1st sensor part 3a in the said bathtub 1 is about several tens of centimeters at all, the influence of the water pressure by the fluctuation | variation of a bathtub water level can be disregarded.
[0042]
<2> In the above-described embodiment, the first and second signal processing units 3b and 4b are respectively connected to the distance L. ₁ And the distance L ₂ The distance L was calculated. ₁ And the distance L ₂ The determination may be made by comparing the reflection times used for calculating the values with the propagation times of ultrasonic waves corresponding to (Lb ± 5%) and (Lw ± 5%), respectively.
[0043]
<3> In the above embodiment, the first and second position detecting means 3 and 4, the first sensor unit 3a and the first signal processing unit 3b, the second sensor unit 4a and the second signal processing unit. 4b is configured separately from each other, and the first and second signal processing units 3b and 4b and the determination unit 5 are integrally formed as a signal processing unit 11, but these configurations are It is not necessarily limited to the above embodiment. For example, the first and second signal processing units 3b, 4b and the determination unit 5 are separated, and the first sensor unit 3a, the first signal processing unit 3b, the second sensor unit 4a, and the second signal processing are separated. The parts 4b may be configured integrally with each other. The distance L ₁ And the distance L ₂ The calculation processing and the comparison determination may be performed by the determination unit 5 without being performed by the first and second signal processing units 3b and 4b.
[0044]
<4> The timing of entering the “warning mode” or “alarm / forced drainage mode”, and other timings and setting of the allowable error range are not limited to the above embodiment, and can be changed as appropriate.
The “warning mode” is not necessarily provided, and the “warning / forced drainage mode” may be directly entered. In this case, the warning generation means 10 is unnecessary.
[0045]
<5> The forced drain means 7 may not necessarily be configured to pump hot water with the motor pump. For example, the water stop of the drain of the bathtub 1 is controlled by a solenoid valve, and when the forced drain means 7 receives the forced drain signal P, the solenoid valve is operated to open the drain. It doesn't matter. Moreover, you may provide in the said bathtub 1 the drain outlet only for forced drainage which provided the solenoid valve. Furthermore, when the forced drain means 7 receives the forced drain signal P, a means for mechanically pulling out the drain plug with a wire or the like may be provided.
[0046]
<6> In the “warning mode” or “alarm / forced drainage mode”, instead of generating the warning sound or warning message or the warning sound or warning message, other output means such as flashing light or vibration are provided. It may be used to generate warnings and alarms.
[0047]
<7> In the above embodiment, the device of the present invention has been shown in a form that can be attached to an existing bathtub later. However, when a bathtub is newly installed, a bathtub in which the device of the present invention is built in is used. It doesn't matter.
[0048]
<8> Release means for releasing the forced release state of the forced drain means 7 is not necessarily provided in the forced drain means 7.
For example, the determination means 5 is provided with a release button or the like for forcibly canceling the “alarm / forced drainage mode”, and the transmission of the forced drainage signal P is stopped simultaneously with the cancellation of the “alarm / forced drainage mode”. The drainage means 7 may be configured to stop the forced drainage simultaneously with the stop of the reception of the forced drainage signal P.
[Brief description of the drawings]
FIG. 1 is an explanatory diagram showing the configuration of an in-tub accident detection device according to the present invention.
FIG. 2 is a perspective view showing an installation state of the in-tub accident detection device according to the present invention.
FIG. 3 is an explanatory diagram for explaining a situation where a bather's head is in a submerged state
[Explanation of symbols]
1 Bathtub
1a First inner wall surface
1b Second inner wall surface
1c Water surface
2 bathers
2a body
2b head
3 First position detecting means
3a 1st sensor part
3b First signal processing unit
4 Second position detection means
4a Second sensor part
4b Second signal processing unit
5 judgment means
6 Emergency information output means
7 Forced drainage means
7a Receiver
7b Drainage section
7c Cancel button
8 Release means
9 Bathroom
9a 1st bathroom inner wall
9b Wall surface in the second bathroom
10 Warning generation means
11 Signal processor
12 Output device
S Bather detection signal
T Submergence detection signal
P Forced drainage signal
W Alarm signal

Claims

First position detecting means capable of detecting the position of the body under the bath water surface of the bather in the bathtub;
Second position detecting means capable of detecting the position of the bather's head;
Determination means for determining abnormal submergence of the head based on both detection outputs of the first position detection means and the second position detection means;
Forced drainage means for forcibly draining hot water in the bathtub based on the determination result of the determination means ;
Release means for releasing the forced drainage state of the forced drainage means ,
The first position detecting means transmits a first ultrasonic sensor that can transmit an ultrasonic signal to the facing object and can receive an ultrasonic signal reflected by the object. In a lower position than the lower limit of, measure the distance to the object, the presence of the bather in the bathtub is detected by the distance is shorter than a predetermined value,
The second position detecting unit is configured to place a second sensor unit capable of transmitting an ultrasonic signal to an object facing and receiving an ultrasonic signal reflected by the object at a position higher than the upper limit of the normal water level. Comprising, measuring the distance to the object, detecting that the bather's head is submerged by the distance being within an allowable error range with respect to a predetermined value,
The determination means is when the first position detection means detects the presence of the bather in the bathtub and the second position detection means detects that the bather's head is submerged. When the state continues for a predetermined time, it is determined that the bather is in an abnormally submerged state, a forced drainage signal is output to the forced drainage unit, and forced drainage by the forced drainage unit is started. Thereafter, when the first position detection unit detects that the distance to the object is apparently long, and the determination unit determines that the abnormal submersion state has been released, the forced drainage is performed by the release unit. In- tub accident detection device whose state is released .

The in-tub accident detection device according to claim 1, further comprising emergency information output means for outputting emergency information based on a determination result of the determination means.

The first position detection means includes first temperature correction means for detecting a water temperature in the bathtub and correcting a propagation speed of an ultrasonic signal transmitted and received by the first sensor unit.
It said second position detecting means and the second sensor portion and the second temperature correction comprises means according to claim 1 or of the second sensor unit detects the ambient air temperature to correct the propagation speed of the ultrasonic signals transmitted and received in 2. The in-tub accident detection device according to 2.

The in-tub accident detection device according to any one of claims 1 to 3, wherein the second sensor unit is installed such that a central axis of an outgoing beam of ultrasonic waves is horizontal.

The determination means first generates a predetermined warning sound or warning message when it is determined that the bather is in a submerged state, and starts forced drainage when the submerged state continues for a predetermined time. The accident detection apparatus in a bathtub according to claim 1 , wherein a forced drainage signal is transmitted to the forced drainage means.