h∫‡′勺Ar［ificiaIOrgans（Volume14．Supp11）
editedbyK・OtaandT．Agishi．
1SAOPress、Cleveland⑥1990．

A Newly Designed Pneumatic Pulse Pump

MembraneOxygenator
S・Hashimoto，＊S・Tominaga，．M・Yoshida，and†Y．Sasaki
J伸′り川！仙り川い川…川′一川川／●川t…′・・＼…∵＝・、‥＼・／いい／・イl／・・J′・仙・人りl旧いJ＝＝川ハ・・
誹＝Jl′′t川・／、／ノ申′り′′…′・／′町血＝＝い・川＝、い＝＼●り人（−・り／り・h〃いり一 人…h′ヾl仙∴′小川

Abstract：Inordertoshortentheextracorporealcirculation
1atedinthegasside（OutSideofthetube），Thecompliance
Circuitandtoincreasetheefficiencyofoxygenation，aneWtestshows thata7％decreaseinthe volumeofblood side
membrane oxygenator combined witha pump was de−（insideofthetube）ismadebyaO．5atmpressuredifference
Signed・Themembranewasformedwithasiliconetube（0．3acrossthemembrane・Thegaspermeabilitytestshowsthat
mminternaldiameter，0．64mmextemaldiameter）．Inthe 13・5mi／minoxygengasispermeatedbyO．5atmpressure
miniature model，1，700pieces（200mmlengtheach）of differenceat24Oc・Themocktestshowsthattheoxygen
tubewerebundledandpackedinapolycarbonate−Cylinder tensionincreasesfroml18mmHgattheinletto354mm
With elastic silicone坑11ers．Inbothinflowalldoutflowsides
Hgattheoutletoftheoxygenatorwhen12mi／min（0．2Ofthecylinder，ballvalveswereequlpped・Thetotalavail−ableareaOfthemembraneisO・19m2．Inthismodel，themembranewaspneumaticallydrivenwiththerecIPrOCatlng

pumplnPerformancetests．inwhich100％oxygencircu−

Inordertoshortentheextracorporealcirculation

Circuit and toincrease the efficiency of oxygen−ation，neW membraneoxygenatorscombined with

thepumpweredesigned．

mistrokevolume）salinesolutionispumped．TheperforT
mancehasbeenmaintainedinanimaltests．KeyWords：

Membraneoxygenator−Pneumaticpulsepumpmembrane
OXygenatOr・

theinlet valveto the outlet valveis37cm3．The
membraneispneumaticallydrivenwithapositive−
PreSSure reSPlratOr SO that the houslng Simulta−
neously plays two roles：the oxygenator and thepump．InthepumplngteSt，themembranewasdriven
byaltemativelychangingpressure（Fig，3）・InmockMETHODS

tests，Saline501ution（240C），inwhichcarbondiox−
ide tension was elevated to45−65mmHg，WaS
introduced．Forthecomparativetestofthegasper−

Twotypesofpneumaticpulsepumpmembrane
OXygenatOrS Were manufactured：One Ofsheet andOneOftubes・Intheformertype，aSiliconesheet（0．032cmthick，260cm2availableareaforgas meability，arOllerpumpwasusedtoimpelthesa−exchange）is held between two parts ofa polyT 1inesolutionwithoutmembranepumping（Fig．4）．
Inanimaltests，adultmongreldogs（Weighing15−
methylmethacrylate housing（80cm31iquid side17kg）wereused．Inthegasside（theonesideofVOlume）（Fig．1）・Inthelattertype（modell−5inthesheetortheoutsideofthetube），100％oxygenFig，2），10−1，700pieces（14−20cmlengtheach）
gas was circulated．In the case ofthe sheet type
Oftubearebundledandpackedinapolycarbonatemodel（Fig．5），theheparinizedbloodwasdrained
Cylinderhousing（aglasscylinderisusedonlyin
themode13）withelasticsiliconefillers（Tablel）．
Inbothinflowandoutnow sidesofthebloodnow
Pathofthehousing，One−Way Valves（nylon bal1）
areequlPPed．Inmode15，thefillingvolumefrom

from theinferior vena cava andinfusedinto theSuperiorvenacava，In thecaseofmode15（tubetype，Fig．6），thebloodwasdrainedfromthefem−
Oralvein（Via silicone tubeofO．3cminternaldi，ameter）andinfusedintothejugularvein（viapoly−
ethylenetubeofO・2cmintemaldiameter）・Theflow

rateattheoutletoftheoxygenatorwas measured
Addresscorrespondence andreprlntrequeStS tODr・S・Hashi−
by an electro magneticflow meter（Fig・7）．The
moto，DepartmentofBioenglneenng，SchoolofMedicine．Kitas−
Permeabilitycoefficients（k）ofoxygenandofcar−
atoUniverslty，15−1，Kitasatol−Chome，Sagamihara−Shi，Kana−bondioxidearecalculatedby

gawa，228Japan．

JβJl∫．〃A∫〃〃オOr（フgrA上．

ノβ2

ひH∈∈︑UHnSSUひhua
TムーH白Tlme l s

FIG．3．Driving pressuretracIngSinthe mocktest・

FJG．1．PneumaticpulsepumpmembraneoxygenatorinsheettYPe．

TABLEl．P乃g〟m血cp血ピタ〟′7甲椚g椚♭r（‡乃gOスブgg乃〟わr∫乃蝕♭gりpピ
Np

CAg（cm2）㌦Lg（cm）
24

10ノl つJ

2V

155100800080

21′LU

100／hU／bqノ2′LU

15251︵U4︵Ul5 424︵U︵U︵U1010000000

10l︵Ul51qノ17︵UつJ0．030
0．030

9696糾糾糾

20．1470．030

ハU

10．147Lt（cm）gModel Di（Cm） De（cm）

71Di，internaldiameter；De．externaldiameter；Lt，tOtallengthofeachtube；Lg，aVailablelengthof
eachtubeforgasexchange；Np，numberofpiecesoftube；Ag，integratedavailable−intemal−areaOftubes
7forgasexchange（Ag＝NpJ7TDiLg）；Vg，integratedavai1able−intemal−VOlumeoftubesforgasexchange
andpumping（Vg＝NpJ7TDi2Lg／4）．

FIG，2．Pneumatic pulse pump membrane oxYgenatOrin tubetYPe：mOdelsl．2，3，4，5（fromleftto right），ln modelsl−3，One−WayValvesare removed．rn mode15，ballvalves are built−in．

〟且Wβ尺AⅣE OズyGEMr（フ尺JβjFIG．4．Mockcircuit：reSPirator（left），PneUmatic puIse pump membrane oxYgenatOr（middle），rOller pump（right）．The roller
PUmPisusedonlYincomparativetests（seetext）・

た＝ヴ（ズル）／Ag，（1）

RESULTS

whereqispermeatedgasflow−rate（Cm3／s），Xis
The compliance testsin models4and5show
thicknessofthemembrane（Cm），Pisthepressurethat a7％decreasein the volume ofblood sideis
difference（dyn／cm2），Agistheavailableareafor madebyapressuredifftrenceof380mmHgacrossgasexchange（Cm2）．
themembrane．ThepumplngteStat24OCinmodel

FIG．5．Animaltestwith sheettYPe．

∫．〃A馴OrO grA⊥．

ノβ4

FIG．6．Animaltestwithtubetype（mode15）．

5shows that alternatively changing（60min1）

and animaltests are summarizedin Table3．The

drivingpressure（Pr）ofOorlOOmmHgimpels7mock tests show that kislargerin membrane

ml／minofwaterandthatProf−1000rlOOmmpumpingthaninrollerpumping（COmPare dataof
Hgimpels17ml／minofwater（Fig．3）whenthe

Saline solutionin Table3）．The animaltestin theinletandoutletpressuresareOand20mmHg，re−tubetypeshowedthatkwasmaintainedevenwhen

SPeCtively．The gas permeability testsin the gas

lOO％oxygengaschangedtotheairinthegasside．

Phaseinmodels3−5showthatkofoxygenis4×

WhentheinletpressurewaslOmmHg，150T400

1012cm4dyn1s1withpressuredifferenceof380

ml／minofbloodwasabletobepumpedwithmem−mmHg at240c．Tensions ofoxygen andcarbon

branepumpinginthesheettype，and6−12ml／min

dioxidein mock and animaltests are exemplified

Ofbloodwasabletobepumpedinthetubetype．
Figure7shows regurgitation atthe ballvalve（ininTable2．Thepermeabilityc（光mCients（k）inmock

themode15）．

Tu可∈DISCUSSION

OfthemembranewassolargethatmembraneruP−tureoccurred．TosoIvetheproblem，thesheettype
WaSChangedtothetubetype．Inmodelsl−3，re−00

二イ■lT∈︑U︺巾h−きOThInthesheettype，fairlygoodpumplngWaSPer−
formed．Inthismodel，however，thepositionofthe
membranesheetwasunstable，andthecompliancegurgltationoccurredbetweenthepottlngfiller．and
ニミ

Timeニ

l s

thehouslngCylinder．Inmodels4and5，thestiffT

ness ofthe cylinderwas modifiedto match with
thatofthepottlngfiller．Themocktestshowsthat
thegaspermeabilitylnCreaSeSbypulsationofflow
in the pneumatic pulse pump membrane oxygen−ator．Thisresultisconsistentwiththepreviousstudy

FIG．7．Flow rate tracingin the animaltest with tube tYPe （1）．Toincreasetheshearrateatthetubewall（サom（mode15）．

the modellto5），flow rateincreased with a de−脚β肌0ⅩyGE〃ArO尺ノβ∫

TABLE2．rビ／l∫わ〃∫q′叩gg〃α〃dc（汀ム∂〃d〜αrfdビf〃椚OCたα乃dd／〜よ椚αJJピ∫J∫
Model Liquid PiO＝PoO2

QI

PiCO2 PoCO2Qg

VsmmHg mmHg mmHg mmHg ml／min ml L／min
sheet blood
55d518l18
12749

salinesalimeblood

19354
326
510

48

405（i4731

31352（i204（X）

712120，260．1

996aLiquidimpellednotwi（hthemembranepumplng，bu（Withtherollerpumpequlppedintheinletlineofhousing（seeFigs・1，2andTablel）；PiO三，OXygentenSion a（inlet；PoO二，OXygen（ension atOutlet；PiCO，，Carbondioxide（ensionatinlet；PoCO2，Carbondioxide（ensionatoutle（；Ql，1iquidflow−rate；Vs，1iquidstrokevolume；Qg，gaSflow−rate・TABLE3．∫〃椚椚αrたどd血Jαルomα乃∫mαJJピ∫J∫α／！dmocたJβ∫J∫
Model

sheet
55d5

Liquidbloodsalinesalineblood

kO2

kCO2ml／mim

cm4dyn】s1cm4dyn）s1

150−400
1212（ト12（6±2）×10一三（2±4）×10】0Ql

3．9×1014

1．5×101＝

3．2×1014

0．8×10￣12（2±1）×10−り（1±1）×1012

OSeeTable2．Model，SeeFigs・1，2andTablelこQl，1iquidflowrate；kO2，Permeabilitycoefficien（Ofoxygen；kCO2，Permeabilitycoefficientofcarbondioxide．

CreaSeOfflowresistance（Shortenthetubelength）
andtheinternaldiameterdecreased．Thecalculated

Shearrates at the tube（0．015cminternalradius）

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l・TanishitaK，Nakano K，Richardson PD，GallettiPM，SugaT
WaraM．SakuraiY・Augmentation ofgas transferwithpul−
SatileflowinthecoiledtubemembraneOXygenatOrdesign．Tlans

wallare22s￣1for6ml／minmeanflowrateandA〝l∫ocA′材J〃Je川0′g（コ乃∫1980；2（i：5（iト65．
220s￣1for60ml／minmaximumflowrate（Fig．
2・HashimotoS・ErythrocytedestruCtionunderperiodicallyfluc−
7）inPoiseuilleflow，Ashearrateof＞400sLlis tua（1ngShearrate：COmParativestudywithconstantshearra（e．
desirabletoinhibitclotformation（2）．

ArJげ0′g（フ那1989；13：458−63．