JPH0239265B2

JPH0239265B2 -

Info

Publication number: JPH0239265B2
Application number: JP58080688A
Authority: JP
Inventors: Takashi Tsuji
Original assignee: Nippon Zeon Co Ltd
Current assignee: Zeon Corp
Priority date: 1983-05-11
Filing date: 1983-05-11
Publication date: 1990-09-04
Also published as: JPS59206699A

Description

[Detailed description of the invention]

本発明は血液ポンプ装置等の気体駆動型ポンプ
の駆動装置に関するものである。この種の駆動装置として、例えば第１図に示す
ように構成したものが知られている。図中符号１
は圧縮機、２は真空ポンプ、３は正圧タンク、４
は負圧タンク、５は電磁切換弁、６は減圧弁であ
る。圧縮機１により正圧タンク３内が所定の正圧に
維持され、また真空ポンプ２により負圧タンク４
内が所定の負圧に維持されていて、電磁切換弁５
により正圧タンク３と負圧タンク４から駆動圧出
口７に設けた血液ポンプ装置等の気体駆動型ポン
プ８に正圧と負圧が交互に作用して（加圧、吸引
して）これを駆動する。上記駆動装置によれば、気体駆動型ポンプ８に
一定圧を供給して定格通りに動作させるために、
正圧タンク３、負圧タンク４のタンク容量を気体
駆動型ポンプ８のポンプ容量に比して数十倍（例
えば40倍〜50倍程度）大きく設定する必要があ
る。この理由は次の通りである。すなわち、電磁切
換弁５により正圧タンク３が開いたときには該タ
ンク３内の圧力が低下し、また負圧タンクが開い
たときには該タンク４内の圧力が上昇するが、タ
ンク容量が充分に大きいときにはこれら圧力低
下、圧力上昇は無視し得る程度である。しかし、
タンク容量が充分でないときには圧力低下、圧力
上昇の割合は大きい。減圧弁６は、一般に応答速
度がそれほど速くないために、これら圧力低下、
圧力上昇を直ちに補償することができず、圧力低
下、圧力上昇の影響が駆動圧出口７や気体駆動型
ポンプ８の圧力波形にあらわれてしまう。第２図
の実線Ａは圧力低下の影響があらわれた圧力波形
を示している。なお、第２図中一点鎖線Ｂは圧力低下のない理
想圧力波形を示し、また点線Ｃは空気の補充がな
い場合の正圧タンク３の圧力曲線を示し、また二
点鎖線Ｄは減圧弁６の動作による圧力曲線を示し
ている。また、駆動圧出口７と気体駆動型ポンプ８との
間の流路が長く、かつこの流路が細い可撓性ホー
スにより形成されている場合には、圧力低下の影
響等の外に管内抵抗及び管の変形等の影響が加わ
り、気体駆動型ポンプ８での圧力波形は第３図実
線Ａに示すようにローパスフイルタを通した如き
波形となつてしまう。特に、血液ポンプ装置では、血液ポンプの呈す
る血圧曲線が自然心臓のそれにできる限り近いこ
と、最も理想的には同じであることが必要であ
り、このため血液ポンプ装置を駆動する装置で
は、上述のような圧力低下や圧力上昇を極力抑え
なければならず、タンク３，４の容量は充分に大
きく設定する必要がある。以上のようにタンク３，４の容量を充分に大き
くする必要があることから、装置はこれらタンク
３，４によりほとんど占められてしまい、小型化
しにくい問題がある。本発明はこのような問題点に鑑みてなされたも
ので、その目的とするところは、一定圧力を供給
して気体駆動型ポンプを定格通りに動作させるこ
とができる上に、タンク容量を小さくして装置全
体を小型化できる気体駆動型ポンプの駆動装置を
提供することである。本発明は、高圧源（圧縮機）に調圧弁（減圧
弁）を介して接続された正圧タンクと、負圧源
（真空ポンプ）に調圧弁（減圧弁）を介して接続
された負圧タンクとを具備し、これらタンクから
駆動圧出口に装備された気体駆動型ポンプに正圧
と負圧とを交互に作用して駆動するようにした気
体駆動型ポンプの駆動装置において、前記正圧タ
ンクよりも小容量で前記高圧源に接続されて該正
圧タンクよりも高圧に加圧された副正圧タンクお
よび／または前記負圧タンクよりも小容量で前記
負圧源に接続されて該負圧タンクよりも低圧に減
圧された副負圧タンクを装備して、正圧タンクか
ら正圧あるいは負圧タンクから負圧を前記気体駆
動型ポンプに作用するとき、これと同期して該副
正圧タンク内の正圧あるいは該副負圧タンク内の
負圧が作用するように構成してなることを特徴と
している。以下本発明の一実施例を図面を参照して説明す
る。第４図は本発明の駆動装置の一例を示すブロツ
ク図である。図中第１図に示す部分と同一部分に
は同一符号を付してその説明を省略する。本実施例では、正圧タンク３ａの入口側の減圧
弁６と圧縮機１との間から分岐して圧縮機１と駆
動圧出口７とを直接連結する分岐ライン１０に正
圧タンク３ａよりも小容量の副正圧タンク１１を
設け、また負圧タンク４ａの入口側の減圧弁６と
真空ポンプ２との間から分岐して真空ポンプ２と
駆動圧出口７とを直接連結する分岐ライン１２に
負圧タンク４ａよりも小容量の副負圧タンク１３
を設けている。副正圧タンク１１内は正圧タンク
３ａよりも高圧に加圧され、また副負圧タンク１
３内は負圧タンク４ａよりも減圧される。そして、副正圧タンク１１の出口側（駆動圧出
口７側）と入口側（圧縮機１側）にはそれぞれ電
磁弁１４，１５を設け、また副負圧タンク１３の
出口側（駆動圧出口７側）と入口側（真空ポンプ
２側）にはそれぞれ電磁弁１６，１７を設けてい
る。電磁弁１４〜１７は図示しない制御装置により
電磁切換弁５と同期して動作する。第５図ａ〜ｅ
は電磁切換弁５と電磁弁１４〜１７のタイミング
チヤートを示している。同図によると、電磁切換
弁５が正圧タンク３ａ側に切換わつたときには、
それと同じ時間電磁弁１４，１７は開き、電磁弁
１５，１６は閉じる。また、負圧タンク４ａ側に
切換わつたときには、それと同じ時間電磁弁１
６，１５は開き、電磁弁１４，１７は閉じる。これにより、電磁切換弁５が正圧タンク３ａ側
に切換わつて、正圧タンク３ａから加圧気体が駆
動圧出口７を通つて気体駆動型ポンプ８に作用す
るとき、これと同期して副正圧タンク１１内の加
圧気体が作用する。また、電磁切換弁５が負圧タ
ンク４ａ側に切換わつて、負圧タンク４ａにより
気体駆動型ポンプ８から駆動圧出口７を通つて気
体を吸引するとき、これと同期して副負圧タンク
１３も気体を吸引する。従つて、正圧タンク３ａ内に圧力低下が発生し
ても、駆動圧出口７、気体駆動型ポンプ８では副
正圧タンク１１からの加圧気体により補償され
て、圧力低下の影響があらわれない。また、負圧タンク４ａ内に圧力上昇が発生して
も、同様に駆動圧出口７、気体駆動型ポンプ８で
は副負圧タンク１３による気体の吸引により補償
されて、圧力上昇の影響があらわれない。第６図及び第７図は加圧気体の供給時における
駆動圧出口７、気体駆動型ポンプ８での圧力波形
を示している。同図によると、正圧タンク３ａの
みでは二点鎖線Ｆに示すように圧力低下の影響に
より、減圧弁６が応答するまでの間、所定圧力に
達しないが、これに副正圧タンク１１を加える
と、該副正圧タンク１１からの加圧気体（点線Ｇ
参照）が減圧弁６が応答するまでの間圧力補償す
るため、駆動圧出口７、気体駆動型ポンプ８での
圧力波形は実線Ｅに示すように理想波形Ｂに近づ
く。なお、第６図の二点鎖線Ｆは第２図に示す実
線Ａと対応し、また第７図の二点鎖線Ｆは第３図
に示す実線Ａと対応している。すなわち、本実施例では、加圧空気の供給当初
や気体吸引当初のみならず、減圧弁６が応答する
までの間、副正圧タンク１１、副負圧タンク１３
が圧力補償を行う。従つて、正圧タンク３ａ、負
圧タンク４ａの容量を小さく設定しても、気体駆
動型ポンプ８を定格通り動作させることができ
る。副正圧タンク１１の容量及び圧力は、例えば次
のようにして設定される。いま、正圧タンク３ａの容量をＢ〔〕〃圧力をＹ〔atm〕副正圧タンク１１の容量をＣ〔〕〃圧力をＸ〔atm〕とし、また気体駆動型ポンプ８と流路（チユー
ブ）との合計容量をＡ〔〕とし、正圧が作用す
る前の圧力（負圧）をＺ〔atm〕とする。電磁切換弁５、電磁弁１４が開いたとき、タン
ク３ａ，１１と負荷（気体駆動型ポンプ８、流
路）の瞬間的な圧力Ｗは次式に示すようになる。
なお、この場合、圧縮機１から減圧弁６を介して
正圧タンク３ａに空気の補給はいまだないものと
する。Ｗ＝（Ｂ×Ｙ）＋（Ａ×Ｚ）＋（Ｃ×Ｘ）／Ａ＋Ｂ＋
Ｃ（atm）…… Ｗ＝Ｙとするためには、正圧タンク３ａからの
流出を０とすればよい。換言すれば、副正圧タン
ク１１によりこの流出を補うようにすればよい。依つて、Ａ（Ｙ−Ｚ）＝Ｃ（Ｘ−Ｙ）となるが、
Ｘ＝Ｙの場合は右辺が０となり、式のＢがＢ＋
Ｃとなつたときに等しくなり効果が表われない。従つて、Ｘ＞Ｙ …… Ａ（Ｙ−Ｚ）≧Ｃ（Ｘ−Ｙ） …… を満足するように副正圧タンク１１の容量及び圧
力を設定すればよい。なお、この場合において、
Ａ（Ｙ−Ｚ）＝KC（Ｘ−Ｙ）Ｋ＝１〜0.01の条件を満すことが好ましい。例えば、Ａ＝0.2〔〕、Ｚ＝0.7〔atm〕Ｂ＝1.0〔〕、Ｙ＝1.3〔atm〕のときに、Ｗ＝1.3〔atm〕にするには、Ｃ＝0.2〔〕、Ｘ＝1.9〔atm〕あるいはＣ＝0.1〔〕、Ｘ＝2.5〔atm〕とすればよい。すなわち、副正圧タンク１１の容量は正圧タン
ク３ａの1/5〜1/10程度に設定でき、副正圧タン
ク１１の圧力は正圧タンク３ａの1.5倍以上に設
定すれば効果がある。副正圧タンク１１の圧力は正圧タンク３ａの
1.5倍以下であると、タンク容量を大きくしなけ
ればならず、また管内抵抗等の影響により効果が
少ない。しかし、10倍以上になると、圧力波形が
第１１図に示すようになり、問題が生じる。従つ
て、副正圧タンク１１の圧力は正圧タンク３ａの
1.5倍から10倍程度に設定するのが好ましい。副正圧タンク１３の容量、圧力も同様に設定さ
れる。この場合、副負圧タンク１３の容量を
C′〔〕、圧力をX′〔atm〕とし、負圧タンク４ａ
の容量をB′〔〕、圧力をY′〔atm〕とし、負圧の
かかる前の気体駆動型ポンプの正圧をZ′〔atm〕
とすれば、 X′＜Ｙ …… A′（Ｙ−Ｚ）≦C′（X′−Ｙ） …… を満足するように設定すればよい。Ａ＝0.2〔〕、Y′＝0.7〔atm〕Ｂ＝1.0〔〕、Z′＝1.3〔atm〕 X′＝0.2〔atm〕のときには、 C′≦0.24〔〕、とすればよい。副正圧タンク１１、副負圧タンク１３を設けな
い場合では、前述の式は次のようになる。Ｗ＝（Ｂ×Ｙ）＋（Ａ×Ｚ）／Ａ＋Ｂここで、Ａ＝0.2〔〕、Ｚ＝0.7〔atm〕とし、ま
たＹ＝1.3〔atm〕とし、Ｗ＝1.3〔atm〕に近づけ
るには、正圧タンク３ａの容量をほぼ10〔〕程
度にしなければならない。すなわち、正圧タンク３ａと副正圧タンク１１
の合計タンク容量（1.2〜1.1〔〕）を第１図に示
す正圧タンク３のタンク容量（10〔〕程度）に
比してかなり小さく設定できる。また、負圧タン
ク４ａと副負圧タンク１３の合計タンク容量も同
様に同図に示す負圧タンク４のタンク容量に比し
てかなり小さく設定できる。気体駆動型ポンプ８には、人工心臓用の血液ポ
ンプ装置が使用される。この血液ポンプ装置は、
例えば第８図に示すように、気体を導入及び排出
する為のポート２０を有した耐圧性のハウジング
アウタケース２１内に偏平袋状の血液チヤンバー
２２を、その上部に設けたつば部２２を介して気
密に収納して構成されている。つば部２３には血
液導入用導管２４と、血液排出用導管２５とがほ
ぼ平行に立設されていて、これら血液導入用導管
２４と血液排出用導管２５には逆止弁２６，２７
が設けられている。ポート２０は駆動圧出口７に接続されていて、
ハウジングアウタケース２１に加圧気体が導入さ
れると、該気体の圧力により血液チヤンバー２２
が押しつぶされ、血液チヤンバー２２内の血液は
逆止弁２７を通じて血液排出用導管２５から押し
出される。次いで、ハウジングアウタケース２１
内を減圧すると、血液チヤンバー２２はその弾性
復元力により膨張し、逆止弁２６が開き血液導入
用導管２４から血液チヤンバー２２内に血液が導
入される。この動作を順次繰返すことによつて、
血液を周期的に送り出す。なお、第４図中２９は圧縮機１の近傍に設けた
タンク、３０は真空ポンプ２の近傍に設けたタン
クである。次に上記実施例の作用を説明する。圧縮機１により正圧タンク３ａ内を所定の正圧
に維持し、また真空ポンプ２により負圧タンク４
ａ内を所定の負圧に維持する。そして、電磁切換
弁５が正圧タンク３ａ側に切換わると、加圧気体
が該電磁切換弁５、駆動圧出口７を通つてポート
２０からハウジングアウタケース２１内に供給さ
れる。このとき、電磁切換弁５に同期して電磁弁
１４が開き、副正圧タンク１１内から正圧タンク
３ａよりも高圧に加圧された加圧気体が該電磁弁
１４、駆動圧出口７を通つてポート２０からハウ
ジングアウタケース２１内へ供給される。従つ
て、減圧弁６が応答するまでの間に正圧タンク３
ａ内に圧力低下が生じても、ハウジングアウタケ
ース２１内の圧力波形には何ら影響を与えない。
このため、ハウジングアウタケース２１内は立上
がりの遅れがなく所定圧力に加圧され、これによ
り血液チヤンバー２２から血液が逆止弁２７を通
じ血液排出用導管２５から押し出される。電磁弁
１４が開いている間、電磁弁１７も開き、副負圧
タンク１３は真空ポンプ２で負圧タンク４ａより
も減圧されて次の動作の準備がなされる。電磁切
換弁５が負圧タンク４ａ側に切換わるとき、該電
磁弁１７は閉じる。次いで、電磁切換弁５が負圧タンク４ａ側に切
換わると、ハウジングアウタケース２１内から気
体がポート２１、駆動圧出口７及び電磁切換弁５
を通り負圧タンク４ａ内に吸引され、該負圧タン
ク４ａから減圧弁６を通り真空ポンプ２より外部
に排出される。このとき、電磁弁１６が開き、副
負圧タンク１３も同様にハウジングアウタケース
１３内から気体を吸引する。従つて、減圧弁６が
応答するまでの間に負圧タンク４ａ内に圧力上昇
が生じても、ハウジングアウタケース２１内の圧
力波形は何ら影響を与えない。このため、ハウジ
ングアウタケース２１内は立下がりの遅れがなく
所定圧力に減圧され、これにより逆止弁２６が開
き（このとき逆止弁２７は閉じている）血液導入
用導管２４から血液が血液チヤンバー２２内に導
入される。電磁弁１６が開いている間、電磁弁１
５も開き、副負圧タンク１１内に圧縮機１から加
圧気体が供給されて正圧タンク３ａ内よりも高圧
に加され次の動作の準備がなされる。電磁切換弁
５が正圧タンク３ａ側に切換わるとき、該電磁弁
１５は閉じる。従つて、血液ポンプ装置を定格通りに動作させ
ることができ、該血液ポンプ装置の呈する血圧曲
線を自然心臓のそれにできる限り近づけることが
可能となる。上記実施例では、血液ポンプ装置に適用した場
合を示したが、これに限定されず、通常の気体駆
動型ポンプに広く適用できる。また、適用する気体駆動型ポンプによつては、
副正圧タンク１１あるいは副負圧タンク１３のい
ずれか一方のみでもよい。さらに、第９図に示すように、副正圧タンク１
１、副負圧タンク１３の出口部（電磁弁１４，１
６の出口部）を駆動圧出口７に接続する代わりに
正圧タンク３ａ、負圧タンク４ａに接続しても、
同様の作用効果が得られる。さらにまた、電磁切換弁５の代わりに、正圧タ
ンク３ａ、負圧タンク４ａの出口側にそれぞれ電
磁弁を設けて、これら電磁弁を交互に開くように
してもよい。以上説明したように本発明によれば、正圧タン
クよりも小容量で高圧源（圧縮機）に接続されて
該正圧タンクよりも高圧に加圧された副正圧タン
クおよび／または負圧タンクよりも小容量で負圧
源（真空ポンプ）に接続されて該負圧タンクより
も低圧に減圧された副負圧タンクを装備して、正
圧タンクから正圧あるいは負圧タンクから負圧を
気体駆動型ポンプに作用するとき、これと同期し
て該副正圧タンク内の正圧あるいは該副負圧タン
ク内の負圧が作用するように構成してなるので、
正圧タンク、負圧タンクのタンク容量を気体駆動
型ポンプのポンプ容量に比して充分に大きく設定
するようなことをしなくても該気体駆動型ポンプ
に一定圧力を供給して定格通り動作させることが
できる。このため、正圧タンク、負圧タンクを小
容量にして装置の小型化を図ることができる。また、副正圧タンク、副負圧タンクを使用する
ので、正圧、負圧作用当初のみならず、正圧タン
ク、負圧タンクの入口側に設けられた減圧弁が該
正圧タンク、該負圧タンク内に発生した圧力低
下、圧力上昇を補償するまでの間、これらの圧力
補償を行うことができ、このためタンク容量、タ
ンク内圧力を適当に設定することによつて気体駆
動型ポンプでの圧力波形を理想波形に近づけるこ
とが可能となる。さらに、駆動圧出口と気体駆動型ポンプとを長
尺な小径の可撓性ホースで連結しても管内抵抗及
び管の変形等の影響を補うことが可能である。次に本発明の具体例を説明する。第４図に示す駆動装置を使用して、ポンプとチ
ユーブとの合計容量が200c.c.の血液ポンプを駆動
しハウジングアウタケース内の圧力波形を圧力ト
ランジユーサにより測定した。得られた圧力波形
はほぼ第６図の実線に示すようになつた。このとき、各タンク３ａ，４ａ，１１，１３の
タンク容量、圧力及び電磁切換弁５、電磁弁１４
〜１７の動作時間は次の通りであつた。タンク３ａ……２〔〕 0.26Kg／cm² タンク４ａ……２〔〕 −0.03Kg／cm² タンク１１……0.07〔〕１Kg／cm² タンク１３……0.07〔〕 −0.79Kg／cm²（−600mmHg）電磁切換弁５ ……正圧タンク３ａ側20mmsec ……負圧タンク４ａ側20mmsec 電磁弁１４，１６……10mmsec 電磁弁１５，１７……30mmsec 比較例として第１図に示す駆動装置を使用し
た。この場合、第１０図の実線で示す圧力波形を
得るためには、タンク容量は次の通りであつた。タンク３……10 タンク４……10 すなわち、本発明では、タンクの合計容量を第
１図に示すものに比してほぼ５分の１まで縮小で
きた。 The present invention relates to a drive device for a gas-driven pump such as a blood pump device. As this type of drive device, one configured as shown in FIG. 1, for example, is known. Code 1 in the diagram
is a compressor, 2 is a vacuum pump, 3 is a positive pressure tank, 4
5 is a negative pressure tank, 5 is an electromagnetic switching valve, and 6 is a pressure reducing valve. The inside of the positive pressure tank 3 is maintained at a predetermined positive pressure by the compressor 1, and the negative pressure tank 4 is maintained by the vacuum pump 2.
The inside of the electromagnetic switching valve 5 is maintained at a predetermined negative pressure.
As a result, positive pressure and negative pressure are alternately applied (pressurized and sucked) from the positive pressure tank 3 and the negative pressure tank 4 to the gas-driven pump 8 such as a blood pump device installed at the drive pressure outlet 7. drive According to the above drive device, in order to supply constant pressure to the gas-driven pump 8 and operate it as rated,
It is necessary to set the tank capacities of the positive pressure tank 3 and the negative pressure tank 4 to several tens of times (for example, about 40 to 50 times) larger than the pump capacity of the gas-driven pump 8. The reason for this is as follows. That is, when the positive pressure tank 3 is opened by the electromagnetic switching valve 5, the pressure inside the tank 3 decreases, and when the negative pressure tank is opened, the pressure inside the tank 4 increases, but the tank capacity is sufficiently large. Sometimes these pressure drops and pressure increases are negligible. but,
When the tank capacity is insufficient, the rate of pressure drop and pressure rise is large. Since the pressure reducing valve 6 generally does not have a very fast response speed, these pressure drops and
It is not possible to immediately compensate for the pressure increase, and the effects of the pressure decrease and pressure increase appear on the pressure waveforms of the drive pressure outlet 7 and the gas-driven pump 8. A solid line A in FIG. 2 shows a pressure waveform affected by the pressure drop. In FIG. 2, the dashed line B shows the ideal pressure waveform with no pressure drop, the dotted line C shows the pressure curve of the positive pressure tank 3 without air replenishment, and the broken line D shows the pressure curve of the pressure reducing valve 6. The pressure curve due to the operation is shown. In addition, if the flow path between the drive pressure outlet 7 and the gas-driven pump 8 is long and this flow path is formed by a thin flexible hose, in addition to the influence of pressure drop, internal resistance With the addition of the effects of deformation of the pipe and the like, the pressure waveform in the gas-driven pump 8 becomes a waveform as if it had passed through a low-pass filter, as shown by the solid line A in FIG. In particular, in blood pump devices, it is necessary that the blood pressure curve exhibited by the blood pump be as close as possible to that of the natural heart, and most ideally, be the same. Such pressure drop and pressure rise must be suppressed as much as possible, and the capacities of the tanks 3 and 4 must be set sufficiently large. As described above, since it is necessary to sufficiently increase the capacity of the tanks 3 and 4, the apparatus is mostly occupied by these tanks 3 and 4, which poses a problem that makes it difficult to downsize the apparatus. The present invention was made in view of these problems, and its purpose is to supply a constant pressure and operate a gas-driven pump as rated, while also reducing the tank capacity. An object of the present invention is to provide a driving device for a gas-driven pump, which can reduce the size of the entire device. The present invention includes a positive pressure tank connected to a high pressure source (compressor) via a pressure regulating valve (pressure reducing valve), and a negative pressure tank connected to a negative pressure source (vacuum pump) via a pressure regulating valve (pressure reducing valve). In a drive device for a gas-driven pump, the tank is configured to alternately apply positive pressure and negative pressure to the gas-driven pump installed at the drive pressure outlet to drive the gas-driven pump. A sub-positive pressure tank that has a smaller capacity than the tank and is connected to the high pressure source and is pressurized to a higher pressure than the positive pressure tank; and/or a sub-positive pressure tank that has a smaller capacity than the negative pressure tank and is connected to the negative pressure source and is pressurized to a higher pressure than the positive pressure tank. An auxiliary negative pressure tank is equipped with a pressure lower than that of the negative pressure tank, and when positive pressure from the positive pressure tank or negative pressure from the negative pressure tank is applied to the gas-driven pump, the auxiliary negative pressure tank is It is characterized by being constructed so that the positive pressure in the positive pressure tank or the negative pressure in the auxiliary negative pressure tank acts. An embodiment of the present invention will be described below with reference to the drawings. FIG. 4 is a block diagram showing an example of the drive device of the present invention. In the figure, the same parts as those shown in FIG. 1 are given the same reference numerals, and the explanation thereof will be omitted. In this embodiment, a branch line 10 that branches from between the pressure reducing valve 6 on the inlet side of the positive pressure tank 3a and the compressor 1 and directly connects the compressor 1 and the drive pressure outlet 7 is connected to the branch line 10 that is connected to the positive pressure tank 3a. A small-capacity auxiliary positive pressure tank 11 is provided, and a branch line 12 branches from between the pressure reducing valve 6 on the inlet side of the negative pressure tank 4a and the vacuum pump 2 and directly connects the vacuum pump 2 and the driving pressure outlet 7. auxiliary negative pressure tank 13 with a smaller capacity than the negative pressure tank 4a.
has been established. The inside of the auxiliary positive pressure tank 11 is pressurized to a higher pressure than the positive pressure tank 3a, and the inside of the auxiliary negative pressure tank 1 is pressurized to a higher pressure than the positive pressure tank 3a.
The pressure inside the tank 3 is lower than that of the negative pressure tank 4a. Solenoid valves 14 and 15 are provided on the outlet side (driving pressure outlet 7 side) and inlet side (compressor 1 side) of the auxiliary positive pressure tank 11, respectively, and the outlet side (driving pressure outlet 7 side) of the auxiliary negative pressure tank 13 is provided with solenoid valves 14 and 15, respectively. Solenoid valves 16 and 17 are provided on the inlet side (vacuum pump 2 side) and the inlet side (vacuum pump 2 side), respectively. The solenoid valves 14 to 17 operate in synchronization with the solenoid switching valve 5 by a control device (not shown). Figure 5 a-e
shows a timing chart of the electromagnetic switching valve 5 and the electromagnetic valves 14 to 17. According to the figure, when the electromagnetic switching valve 5 is switched to the positive pressure tank 3a side,
During the same period, the solenoid valves 14 and 17 are opened and the solenoid valves 15 and 16 are closed. Also, when switching to the negative pressure tank 4a side, the solenoid valve 1
6 and 15 are opened, and solenoid valves 14 and 17 are closed. As a result, when the electromagnetic switching valve 5 is switched to the positive pressure tank 3a side and the pressurized gas from the positive pressure tank 3a acts on the gas-driven pump 8 through the drive pressure outlet 7, it is synchronously The pressurized gas in the positive pressure tank 11 acts. Further, when the electromagnetic switching valve 5 switches to the negative pressure tank 4a side and the negative pressure tank 4a sucks gas from the gas-driven pump 8 through the drive pressure outlet 7, the auxiliary negative pressure tank 13 also sucks gas. Therefore, even if a pressure drop occurs in the positive pressure tank 3a, the driving pressure outlet 7 and the gas-driven pump 8 are compensated for by the pressurized gas from the auxiliary positive pressure tank 11, and the effect of the pressure drop does not appear. . Furthermore, even if a pressure increase occurs in the negative pressure tank 4a, the driving pressure outlet 7 and the gas-driven pump 8 are compensated for by suction of gas by the auxiliary negative pressure tank 13, so that the influence of the pressure increase does not appear. . 6 and 7 show pressure waveforms at the driving pressure outlet 7 and the gas-driven pump 8 when pressurized gas is supplied. According to the figure, with only the positive pressure tank 3a, the predetermined pressure is not reached until the pressure reducing valve 6 responds due to the influence of pressure drop as shown by the two-dot chain line F, but the sub positive pressure tank 11 is added. When added, the pressurized gas from the auxiliary positive pressure tank 11 (dotted line G
(see) compensates the pressure until the pressure reducing valve 6 responds, so the pressure waveform at the driving pressure outlet 7 and the gas-driven pump 8 approaches the ideal waveform B as shown by the solid line E. The two-dot chain line F in FIG. 6 corresponds to the solid line A shown in FIG. 2, and the two-dot chain line F in FIG. 7 corresponds to the solid line A shown in FIG. 3. That is, in this embodiment, the sub positive pressure tank 11 and the sub negative pressure tank 13 are not only used when pressurized air is supplied or when gas is sucked, but also until the pressure reducing valve 6 responds.
performs pressure compensation. Therefore, even if the capacities of the positive pressure tank 3a and the negative pressure tank 4a are set small, the gas-driven pump 8 can be operated as rated. The capacity and pressure of the auxiliary positive pressure tank 11 are set, for example, as follows. Now, let the capacity of the positive pressure tank 3a be B[], the pressure be Y[atm], the capacity of the auxiliary positive pressure tank 11 be C[], the pressure be X[atm], and the gas-driven pump 8 and the flow path (tube). ) and the total capacity is A[], and the pressure before positive pressure (negative pressure) is Z[atm]. When the electromagnetic switching valve 5 and the electromagnetic valve 14 are opened, the instantaneous pressure W of the tanks 3a, 11 and the load (gas-driven pump 8, flow path) is expressed by the following equation.
In this case, it is assumed that air has not yet been replenished from the compressor 1 to the positive pressure tank 3a via the pressure reducing valve 6. W=(B×Y)+(A×Z)+(C×X)/A+B+
C (atm)... In order to make W=Y, the outflow from the positive pressure tank 3a should be set to 0. In other words, this outflow may be supplemented by the auxiliary positive pressure tank 11. Therefore, A(Y-Z)=C(X-Y),
If X=Y, the right side becomes 0, and B in the equation becomes B+
When it becomes C, it becomes equal and no effect appears. Therefore, the capacity and pressure of the auxiliary positive pressure tank 11 may be set so as to satisfy X>Y... A(Y-Z)≧C(X-Y).... In this case,
A(Y-Z)=KC(X-Y) It is preferable to satisfy the condition of K=1 to 0.01. For example, when A = 0.2 [], Z = 0.7 [atm], B = 1.0 [], Y = 1.3 [atm], to set W = 1.3 [atm], C = 0.2 [], X = 1.9 [atm] Or C=0.1[], X=2.5[atm]. That is, the capacity of the auxiliary positive pressure tank 11 can be set to about 1/5 to 1/10 of the positive pressure tank 3a, and it is effective if the pressure of the auxiliary positive pressure tank 11 is set to 1.5 times or more that of the positive pressure tank 3a. . The pressure of the auxiliary positive pressure tank 11 is equal to that of the positive pressure tank 3a.
If it is 1.5 times or less, the tank capacity must be increased, and the effect will be less due to the influence of pipe resistance, etc. However, when the pressure increases by more than 10 times, the pressure waveform becomes as shown in FIG. 11, and a problem arises. Therefore, the pressure in the auxiliary positive pressure tank 11 is equal to that of the positive pressure tank 3a.
It is preferable to set it to about 1.5 times to 10 times. The capacity and pressure of the auxiliary positive pressure tank 13 are also set in the same manner. In this case, the capacity of the auxiliary negative pressure tank 13 is
C' [], pressure is X' [atm], negative pressure tank 4a
The capacity of the pump is B′ [], the pressure is Y′ [atm], and the positive pressure of the gas-driven pump before negative pressure is applied is Z′ [atm].
If so, the setting should be made to satisfy X'<Y... A'(Y-Z)≦C'(X'-Y)... When A = 0.2 [], Y' = 0.7 [atm], B = 1.0 [], Z' = 1.3 [atm], and X' = 0.2 [atm], C'≦0.24 []. In the case where the auxiliary positive pressure tank 11 and the auxiliary negative pressure tank 13 are not provided, the above equation becomes as follows. W = (B x Y) + (A x Z) / A + B Here, let A = 0.2 [], Z = 0.7 [atm], and Y = 1.3 [atm], and approach W = 1.3 [atm]. In this case, the capacity of the positive pressure tank 3a must be approximately 10 []. That is, the positive pressure tank 3a and the sub positive pressure tank 11
The total tank capacity (1.2 to 1.1 []) can be set considerably smaller than the tank capacity (about 10 []) of the positive pressure tank 3 shown in FIG. Further, the total tank capacity of the negative pressure tank 4a and the auxiliary negative pressure tank 13 can be similarly set to be considerably smaller than the tank capacity of the negative pressure tank 4 shown in the figure. As the gas-driven pump 8, a blood pump device for an artificial heart is used. This blood pump device
For example, as shown in FIG. 8, a flat bag-shaped blood chamber 22 is placed inside a pressure-resistant housing outer case 21 having ports 20 for introducing and discharging gas, and a blood chamber 22 is placed in the upper part of the chamber through a collar 22 provided at the top of the chamber. It is configured to be stored airtight. A blood introduction conduit 24 and a blood discharge conduit 25 are erected in substantially parallel to the collar 23, and these blood introduction conduit 24 and blood discharge conduit 25 have check valves 26, 27.
is provided. The port 20 is connected to the drive pressure outlet 7,
When pressurized gas is introduced into the housing outer case 21, the pressure of the gas causes the blood chamber 22 to
is crushed and the blood in the blood chamber 22 is forced out of the blood drainage conduit 25 through the check valve 27. Next, the housing outer case 21
When the internal pressure is reduced, the blood chamber 22 expands due to its elastic restoring force, the check valve 26 opens, and blood is introduced into the blood chamber 22 from the blood introduction conduit 24. By repeating this operation sequentially,
Pump blood periodically. In addition, in FIG. 4, 29 is a tank provided near the compressor 1, and 30 is a tank provided near the vacuum pump 2. Next, the operation of the above embodiment will be explained. The compressor 1 maintains a predetermined positive pressure in the positive pressure tank 3a, and the vacuum pump 2 maintains the negative pressure tank 4.
Maintain a predetermined negative pressure inside a. When the electromagnetic switching valve 5 is switched to the positive pressure tank 3a side, pressurized gas is supplied from the port 20 into the housing outer case 21 through the electromagnetic switching valve 5 and the drive pressure outlet 7. At this time, the solenoid valve 14 opens in synchronization with the solenoid switching valve 5, and pressurized gas pressurized to a higher pressure than the positive pressure tank 3a from the auxiliary positive pressure tank 11 flows through the solenoid valve 14 and the drive pressure outlet 7. It is supplied through the port 20 into the housing outer case 21 . Therefore, until the pressure reducing valve 6 responds, the positive pressure tank 3
Even if a pressure drop occurs within the housing outer case 21, the pressure waveform within the housing outer case 21 is not affected at all.
Therefore, the inside of the housing outer case 21 is pressurized to a predetermined pressure without any delay in rising, and as a result, blood from the blood chamber 22 is pushed out from the blood discharge conduit 25 through the check valve 27. While the solenoid valve 14 is open, the solenoid valve 17 is also opened, and the auxiliary negative pressure tank 13 is reduced in pressure by the vacuum pump 2 compared to the negative pressure tank 4a to prepare for the next operation. When the electromagnetic switching valve 5 is switched to the negative pressure tank 4a side, the electromagnetic valve 17 is closed. Next, when the electromagnetic switching valve 5 is switched to the negative pressure tank 4a side, gas flows from inside the housing outer case 21 to the port 21, the driving pressure outlet 7, and the electromagnetic switching valve 5.
It passes through the negative pressure tank 4a, passes through the pressure reducing valve 6, and is discharged to the outside by the vacuum pump 2. At this time, the solenoid valve 16 opens, and the auxiliary negative pressure tank 13 also sucks gas from inside the housing outer case 13. Therefore, even if the pressure rises in the negative pressure tank 4a until the pressure reducing valve 6 responds, the pressure waveform in the housing outer case 21 is not affected at all. Therefore, the inside of the housing outer case 21 is reduced to a predetermined pressure without any delay in falling, and as a result, the check valve 26 opens (at this time, the check valve 27 is closed), and the blood flows from the blood introduction conduit 24. is introduced into the chamber 22. While the solenoid valve 16 is open, the solenoid valve 1
5 is also opened, pressurized gas is supplied from the compressor 1 into the auxiliary negative pressure tank 11, and the pressure is higher than that in the positive pressure tank 3a, thereby preparing for the next operation. When the electromagnetic switching valve 5 is switched to the positive pressure tank 3a side, the electromagnetic valve 15 is closed. Therefore, the blood pump device can be operated as rated, and the blood pressure curve exhibited by the blood pump device can be made as close as possible to that of a natural heart. In the above embodiment, a case where the present invention is applied to a blood pump device is shown, but the present invention is not limited to this, and can be widely applied to ordinary gas-driven pumps. Also, depending on the gas-driven pump used,
Only either the sub-positive pressure tank 11 or the sub-negative pressure tank 13 may be provided. Furthermore, as shown in FIG. 9, the auxiliary positive pressure tank 1
1. Outlet part of auxiliary negative pressure tank 13 (electromagnetic valve 14, 1
6) to the positive pressure tank 3a and negative pressure tank 4a instead of connecting the drive pressure outlet 7 to the driving pressure outlet 7.
Similar effects can be obtained. Furthermore, instead of the electromagnetic switching valve 5, electromagnetic valves may be provided on the outlet sides of the positive pressure tank 3a and the negative pressure tank 4a, respectively, and these electromagnetic valves may be opened alternately. As explained above, according to the present invention, there is provided an auxiliary positive pressure tank and/or a negative pressure tank that has a smaller capacity than a positive pressure tank and is connected to a high pressure source (compressor) and is pressurized to a higher pressure than the positive pressure tank. Equipped with an auxiliary negative pressure tank that has a smaller capacity than the tank and is connected to a negative pressure source (vacuum pump) and is reduced to a lower pressure than the negative pressure tank, so that positive pressure from the positive pressure tank or negative pressure from the negative pressure tank is When acting on the gas-driven pump, the positive pressure in the auxiliary positive pressure tank or the negative pressure in the auxiliary negative pressure tank acts in synchronization with this,
A constant pressure can be supplied to the gas-driven pump and it will operate as rated without having to set the tank capacity of the positive pressure tank or negative pressure tank sufficiently larger than the pump capacity of the gas-driven pump. can be done. Therefore, the positive pressure tank and the negative pressure tank can be made small in capacity, thereby making it possible to downsize the device. In addition, since an auxiliary positive pressure tank and an auxiliary negative pressure tank are used, the pressure reducing valve installed on the inlet side of the positive pressure tank and negative pressure tank is used not only at the beginning of positive pressure and negative pressure effects, but also when Until the pressure drop and pressure increase that occur in the negative pressure tank are compensated for, these pressures can be compensated for. Therefore, by appropriately setting the tank capacity and tank pressure, the gas-driven pump This makes it possible to bring the pressure waveform at close to the ideal waveform. Furthermore, even if the drive pressure outlet and the gas-driven pump are connected by a long, small-diameter flexible hose, it is possible to compensate for the effects of internal resistance and deformation of the pipe. Next, specific examples of the present invention will be explained. Using the drive device shown in FIG. 4, a blood pump with a total capacity of 200 c.c. of the pump and tube was driven, and the pressure waveform inside the housing outer case was measured with a pressure transducer. The obtained pressure waveform was approximately as shown by the solid line in FIG. At this time, the tank capacity and pressure of each tank 3a, 4a, 11, 13, solenoid switching valve 5, solenoid valve 14
The operating time for ~17 was as follows. Tank 3a...2 [] 0.26Kg/cm ² Tank 4a...2 [] -0.03Kg/cm ² Tank 11...0.07 [] 1Kg/cm ² Tank 13...0.07 [] -0.79Kg/cm ² ( -600mmHg) Solenoid switching valve 5...Positive pressure tank 3a side 20mmsec...Negative pressure tank 4a side 20mmsec Solenoid valves 14, 16...10mmsec Solenoid valves 15, 17...30mmsec As a comparative example, the drive device shown in Fig. 1 was used. used. In this case, in order to obtain the pressure waveform shown by the solid line in FIG. 10, the tank capacity was as follows. Tank 3...10 Tank 4...10 That is, in the present invention, the total capacity of the tanks can be reduced to approximately one-fifth of that shown in FIG.

[Brief explanation of drawings]

第１図は従来の装置のブロツク図、第２図及び
第３図は圧力低下の影響が表われた圧力波形図、
第４図は本発明の一実施例を示すブロツク図、第
５図ａ〜ｅは電磁切換弁５、電磁弁１４〜１７の
タイムチヤート、第６図及び第７図は本発明の装
置を使用したときの圧力波形図、第８図は血液ポ
ンプ装置の一例を示す分解斜視図、第９図は他の
実施例を示す一部省略ブロツク図、第１０図は第
１図に示す装置を使用したときの圧力波形図、第
１１図は副正圧タンクを加圧しすぎた場合の圧力
波形図である。１…高圧源（圧縮機）、２…負圧源（真空ポン
プ）、３ａ…正圧タンク、４ａ…負圧タンク、６
…減圧弁、７…駆動圧出口、８…気体駆動型ポン
プ、１１…副正圧タンク、１３…副負圧タンク、
５…電磁切換弁、１４〜１７…電磁弁。 Figure 1 is a block diagram of a conventional device, Figures 2 and 3 are pressure waveform diagrams showing the effects of pressure drop,
Fig. 4 is a block diagram showing one embodiment of the present invention, Figs. 5 a to e are time charts of the electromagnetic switching valve 5 and electromagnetic valves 14 to 17, and Figs. 6 and 7 are diagrams showing the use of the device of the present invention. 8 is an exploded perspective view showing an example of a blood pump device, FIG. 9 is a partially omitted block diagram showing another embodiment, and FIG. 10 is a diagram showing the use of the device shown in FIG. 1. FIG. 11 is a pressure waveform diagram when the auxiliary positive pressure tank is pressurized too much. 1... High pressure source (compressor), 2... Negative pressure source (vacuum pump), 3a... Positive pressure tank, 4a... Negative pressure tank, 6
... Pressure reducing valve, 7... Driving pressure outlet, 8... Gas-driven pump, 11... Sub-positive pressure tank, 13... Sub-negative pressure tank,
5... Solenoid switching valve, 14-17... Solenoid valve.

Claims

[Claims]

1 A gas-driven type equipped with a positive pressure tank connected to a high pressure source via a pressure regulating valve, and a negative pressure tank connected to a negative pressure source via a pressure regulating valve, and equipped with a drive pressure outlet from these tanks. In a drive device for a gas-driven pump configured to drive the pump by applying positive pressure and negative pressure alternately, the pump has a smaller capacity than the positive pressure tank, is connected to the high pressure source, and is larger than the positive pressure tank. Equipped with a secondary positive pressure tank pressurized to a high pressure and/or a secondary negative pressure tank having a smaller capacity than the negative pressure tank and connected to the negative pressure source and reduced in pressure to a lower pressure than the negative pressure tank, When positive pressure from the positive pressure tank or negative pressure from the negative pressure tank is applied to the gas-driven pump, positive pressure in the auxiliary positive pressure tank or negative pressure in the auxiliary negative pressure tank is applied simultaneously. A driving device for a gas-driven pump, characterized in that it is configured to do so.