Ar仰cJβJOrg（1／7∫

12（1）：67−77，RavenPress，Ltd．，NewYork⑥1988lnterna【jona］SocietyfbrArtifjcialOrgans

EffbctofRightVentricularBypassPeakFlow−Rateon
IntrapulmonaryShuntRatio
ShigehiroHashimotoand＊HoshihitoMoriya
β叩rr〃J刀ピ〃J扉−βわピ瑚メナ7ピピノイノーg，∫（ソ7〃〃／qf〃ピdJぐ／〃ピ，付加∫〟J〃U／血・ピタ・．†恒，∫〟g〟m／ム〃川，・r川d＊β叩rげ仙川J〃■r／l〃Jてーぐf（・∫＝■gaり・，∫ぐム00／（れWビd／ぐf〃P，U／油，ピJ■∫わ（オル〟g（フ）・rr，Ⅳ〃gO）▼（ー，∫叩〟〃

Abstract：Theeffectoftotalrightventricularbypasspeak

theintrapulmonaryshuntratiorangedbetweenO．095andnow−rateOntheintrapulmonaryshuntratiowasquantita−O．392thereisnoclearrelationtothepeak−flow−rateindex（Whichvariedfroml．1−17．01min．1m￣2）overthepre−
tivelylnVeStlgatedin animaltests．「Ib glVe Variationsin
Ceding30min．Thisstudydemonstratesthattheintrapul−
thepeaknow−rate（frompulsatiletointermediatetonon−
Pulsatile），three types ofblood pump（Piston−bellows、monaryshuntratioisabletobekeptwithintherangeof
SCreW，and centrifugal）wereapplied todogs．Theintra− COntrOIvaluesfbr6hevenwithapeak−flow−rateindexof＜4・OLmin1m￣2．KeyWords：Rightventricularbypass−Pulmonaryshuntratiowascalculatedftombloodoxygen
COntentdrawnevery3Ominftomtheout】etoftheright1ntrapulmonary shunt ratio−Peakflow−rate−Piston−bel］ows pump−Screw pump−CentrifugaJpump−Pul−
Ventricular bypass pump and from the femoralartery．
Satileflow−Nonpulsati】enow．
While the caninelungwas ventilated withlOO％oxygen
gasbyanartificialresplratOr．Theresultsshowthatwhen

In designlng tOtalventricular bypass systems．
e．g．，a tOtalarti坑cialheart，the question ofpulsatil−
1tyaSadesignrequlrement丘）rCirculatorysystems
arises．Forexample，ifapulsatiJepumpisdesigned
toimitate the naturalheart，Whatis the minimum
Pulsatilityrequiredtomaintainnormalphysio］ogy？

Tbproducewidevariationsintheflowwave−fbrmbeenusedclinically．Tbquantitatepulsatility，peakflow−rateS reSu】tlngfrom each device were care−fu11y controlled whjle meanflow−rateS Were main−tainedwithinthecontro］range．

Tbexamine some ofthe physiologlCaleffects ofpulsatility，the authors bcused on the pulmonary
Circulation；SinceitinvoIves only one organ，the（andthenstudytheresultingphysiologicaleffects）， 】ungs，andsinceinitscapiJlariesthecontrolblood
theauthors usedthreetypes ofbloodpumps；i．e．，flowispuLsatile（1）．Atotalrightventricularbypass（a）piston−bellows type（positive displacement
WaSPerfbrmedinanimalexperimentssothatvari−
PumP）、（b）screw type（intermediate pulsatjlity），
abJepulsatiLitycouldbeappliedtothelungvascularand（c）centrifugaltype（nonpulsatile）．The first SyStem．Evaluation ofthe efftcts ofpulsatility on

glVeS Variablepulsatileflows whicharecontrolled
bythecycJicchangesofahydraulicaLlydrivenarti−

the pulmonary circulation was based on the efn−
Ciencyofoxygenuptake，Whichwasexperimentally
ficial−Ventrjcular vo］ume．The second generates
determinedfrom the oxygen contentin the blood
SOmeWhatnonpulsatileflowswhichcanbepropor−
byintrapulmonary shunt ratio equations．Thesetional］ycontrolledbytherotorspeed．Thethirdisa equations have often been clinicallyused toeval−
uatepulmonaryfunctjonandhypoxemia（2）．

COmPlete］y nonpu】satiledevice which hasrecently

MATERIALSANDMETHODS

ReceivedSeptember1986；revisedAugust1987．
Addresscorrespondenceandrepl−1ntrequeStStODr．Shigehiro
Hashimoto at Bioenglneering，Schoolof Medicine，Kitasato
しniverslty，15−1．Kitasatol−Chome．Sagamihara−Shi，228Kan−（piston−be1lows type，SCreW tyPe，and centrifugalと1ga＼lra．Japan．

type）havebeenmanuねcturedtogivevariationsin

67

lnthepresent study，threetypes ofblood pump．＼．／／．1．＼／／／．1J（りイ）．1．＼ ハJ／‥り（）〟／ト16β

thepeakflow−rate（Qpe。k）・Thebasicmechanismof

ThecyclicvariationsofVcanbedirectlycalcu一
Iated from the pIStOn−mOtion，Whichis eJectricallymeasuI−ed by the position sensor（potentiometer
Piston−bellowspump
LP−10FB，Midori−preCisions，Japan）．The pulse−
ThepIStOn−bellowspumpconsistsofanartificial
ratewasfixedat】20min▼1inthefbllowlnganimal
Ventricle，adiaphragmdrivlngChamber，aCylinder

eachpumpisdescribedbelow．

tests．

Withbellows，tWOdrivlngtubes（connectlngthedia−

PhragmdrivlngChambertothecylinder），aplStOn／ Screwpump

CamSyStem，andanACmotor（Fig．1）．
A cyclic variation of V（artificial−Ventricular

The screw pump consists ofa rotor（made of

Stainless steel；Iwaki、Japan）．a stator（nitri】e
VOIume）isgeneratedbythemechanismasfbllows．rubber），a CaSing（polymethy】methacrylate），anda
Arotと1tiona】motionoftheACmotor（FujiElectric，
DC motor（Sawamural〕enki，Japan）（Fig．2）．The
Japan）is converted to a reciprocating motion by
PumPing mechanismis as follows．The rotor（athepIStOn／camsystem；aPIStOnispushedbyacy−
Slngle−threaded externalscre両isinscribedin the
Lindricalcamin systoleandpulledback bya coil−
StatOr（a double−threadedinterior screw）with a
SPrlngindiastole．ThisrecIPrOCatlngmOtioniscon−SPaCe betweenthem；inotherwords，the spaceis

Vertedtocyclicvariationsinvolumebythewe）ded

metalbellows（madeofstainlesssteel，45cm2crosssealed between two spiral lines where the rotor
contacts with the stator．The bloodin this sealed

SeCtionalarea；Eag］eIndustry，Japan）．Then，this SPaCeis transftrredfrominlet to outlet with one−
Variation ofvolumeis transmitted to a variation of
Way Sliding motion ofthese splral）ines when theV through drivlng Water；in other words，the dia−rotoris rotated bytheDC motor．The meanflow−
Phragm（siliconrubber．1mmthick）oftheartificialrate（0．26to6．761min1）isproportiona】tc・thero−
Ventricle（Withpo）ymethylmethと1Cry）atehousing）is
tatingspeedoftherotor（100−2600minl．
hydraulicallydriven．

rIb smooththeflowofwater，thedrivlngSyStem
isprovidedwithaone−Wayflowpath；COnSistlngOf

two tubes（made ofpolyvinyLchloride stiffened byPOlyesterfiber）．ofaone−WayValve，andofaparti−
tion film（si】icone rubber二1mm thick）．This film

Partitions thedrivlngWaterintotwoparts；thatinthec・ne−WaynOWpathandthatinthecylinder．

Centrifugalpump
The centrifugalpump consists ofanimpeller（made ofpolypropyLene二1waki，Japan），a front
CaSing（po］ymethylmethacrylate）．a rear casing（polypropylene），adrivingmagnet，andaDCmotor（SawamuraDenki．Japan）（Fig．3）．

The pumplng meChanism ofthis deviceis as

Tb convert this variationofV topulsatileflow，

fbllows．Bloodis suckedintotheinlet−POrt Ofthe
theartificialventricleisequlPpedwithと1COupleof CaSlng．impelledfromthecentertothefringe．andballvalves（nylon ball，19．1mm diameter：15mm qectedthroughthe outlet−POrtOfthecaslng．This
Orificediameter）fbrtheinletandoutlet．

Thepeaknow−rateCanbevariedindependentZyCentrifugalefftctisderivedfromtherotationofthe
impeller・The rotationalmotion oftheimpelleris

driven by magnetic couplingfrom that ofthe DC
from Qmean（meanflow−rate）by the fo1lowing
method．Theeccentricradiusofthecy】indricalcam motor（Fig．3b）．
（ER）issetwithvariationbetween2．5and15mmto Themeanflow−rateis contro］ledbytherotatlng
SPeed（100−3500min￣】）c・ftheimpe））er．Whenthisa（りusttheamplitudeofthesinusoidalrecIPrOCatlng
motionofthepIStOn．WhenERisdoubled、SOisthe is setat3500minrl，221minrlwaterispumped
maximuminstantaneouspIStOn−Veloclty，Whichde− agalnStaPl−esSuredifferenceofコ00mmHgbetween
terminesQpeak・Then，themicrometer−headisposiT inlet and outlet．
tionedtoadjustthestroke−lengthofthepiston（SL）

bycuttlngOffapartofsinusoidalmotioninthedia−
StOlic phase．This stroke−1engthproportional1yde−
termines the stroke−VOlume（SV），1Themeanflow−rate（max．5．94lmin▼1）istheproductofSV（0−30ml）andf（pulserate；40−198min1）；thelatteris
COntrOlledbytherotatlngSPeedofthemotor．Thus，

AnimaI tests

lbtalright ventricular bypass was perfbrmedin
21adultmongreldogs（weighingbetween15and31kg）with three typeS Ofblood pump．Thatis、・21
dogsweredividedintothreegroupsasfbllows：（a）
inlldogswiththepIStOn−beLLowstype．（blinthreedogswith the screw type，and（c）in seven dogs
Q。eakCanbevariedindependentlyofQmea。byad−With
the centrifugaltype．1n the first group（With
JuStingERandSLseparate）y．
the piston−be1lows type），ER was varied between
2・5and15mmtoproduce variationsinQpe。kaC−
11nthestrictsense．thisisaccuratewhentheregurgLtantf］ow
throuEhthevalvesislgnOred．
COrdingtothefbllowlngthreegroups；（a−1）infive．4JイげOJ・押m」 り／．J2、Ⅳ0．ノ，ノ9gβナノVmAf〉Uエ〃OM尺y5

69」打U∧rrV5＼P且4斤兄OW一月ArE

FIG．1．Piston−beIlows pump．ExternaIappearance（A）anddiagram（B）．B，bellows；T，drivingtube：IV，inIetvaIve；OV，
OUtlet valve．

dogs with2．5mm，（a−2）infivedogs with7．5mm，ratio（s）wereca】culatedfromtheoxygencontentin
and（a−3）inonedogwith15．Omm．
blooddrawnfromthefemoralartery（02CTa）andTheanimalswereanesthetizedwithsodiumpen−
femoralvein（02CTv）．The computations were
tobarbital（25mg／kg body weight）and ventilated
done uslng the equation−Set eXPlainedinthefol−
through an endotrachealtubewithoxygengas（in− lowlng SeCtion．tit】ed‥intrapulmonary shunt ratio
CludingO．5vol．％halothanetokeeptheanesthetic calculation．
State）by a positive−PreSSure reSPirator（breathing
Beforecannulation．acontro］wave−formofflow−
rate；25min1）．Thefluid（heparinizedsalinesolu−rate（Q）at the pulmonary trunk was measuredtion）−filled catheters（attached to the pressureusing an electromagneticflow−meter（MFV−1100，
transducers）wereintroducedintotherightftmoral
Nihon−kohden，Japan）withacufトtypeprobe．The
arteryandintothevenacavaviatherightfbmoralf）uid−filledcathetersattachedtothepressuretrans−

Vein to measure the ftmoralarterialpressure andducersweretheninsertedintothepulmonarytrunk

the centralvenous pressure，reSPeCtively．These andintotheleftatriumtomeasurepulmonary−arte−rial（RAP）andleft−atrial（LAP）pressures，reSPeC−
Cと1theterswerealsousedfbrdrawlngbloodtomea−
SureOXygenCOntentSOfarterialblood（02CTh）and tively．
After systemic heparinization（2．5mg／kg bodyOfvenousblood（02CTv）．Anothercatheterwasin−
troducedinto theleft ftmoralvein．Through thisWeight），Cannulae（made ofpolyvinylchloride，9mminternaldiameter）wereintroducedintothepul−
Catheter，JuStenOughvolumeofsalinesolutionwas

SuPPlied to maintain a proper circulatlng bJood
VOlume and hence a physiologlCalcentralvenous
PreSSureduringtheanimalexperiments．
SurglCalaccesswasgainedthroughtheleftfburthmonarytrunkandintotherightatriumviatheright

VOIumeoftheresplratOrWaSincreasedsothatthe
Caninelung was fullyinflated with no collapsed
lobes（novjsibleatelectaticareas）．Underthiscon−

Ontheconnectorintheoutflow−Pathofthepump
WaS a Catheter fbr drawlng blood to measure ox−ygen content．The electromagneticflow probe

dition，COntrOJvaluesoftheintrapulmonary shunt（FF−160T，Nihon−kohden，Japan）wasincorporated

Ventricle（Fig．4）．Thesecannulaewereconnectedto thepump（primedwithheparinized saline solu−tion）by connectors（POlymethylmethacrylate）andinterspace．Afterthelungwasexposed，thestroke− tubes（polyvinylchloride，15mminternaldiameter）．

A′J甘0′g〟〃∫，VoJ．J2，Ⅳ0．J，J9ββ

70．†．／／∴し†JJハJりT（）．・l．＼ J）JJ．．りり尺ノ卜1

FIG．2．Screwpump．Externalappearance（A）anddiagram（B）．M，f10W−meter；l，inLet：○，Outlet

FIG・3・Centrifugalpump・Externalappe？ranCe（A）anddia−gram（B）・C，COntrOller；M，f10W−meter；l，lnlet；○，OutIet，

ArげOrg召／！、−，t 0／．J2．Ⅳ0．ノ，ノ9ββ

J」Vr尺Af）U上〃OM尺y5 〟UN7l′′∫．P且4〟兄0Ⅵ／一尺ArE

7ノinto the blood outflow−path ofthe pumpfbrmea−
Suringthewave−fbrmofQ．Athermometerwasalso

incorporated there to measure blood temperature（T）．Partialright ventricular bypass was started，
巾1thefollowedimmediatelybytotalrightventricularby−pass．Thiswasaccomplishedbytighteningwiththe
SnareWhichoccludedtheproximalsideofthepul−

blood−gaS
analyzer

monarytrunk（Fig．4）．
For30min，Qme。nWaSkeptconstant（aconstantvalue had beenselectedbetweenO．8and2．5lminrlmL2）by controllingcirculatingblood volumewith
theaid ofsaline solution．Atthe sametime，pumpdrive conditions，rlamely，the stroke−1ength ofthe
piston（piston−bellowspump），therotatingspeedof
theimpeller（Centrifuga】pump），Or the rotating
SPeed ofthe rotor（SCreW PumP），Were kept fixed
fbr30min．

Theflow−rateindex（QI）isthequotientofflow−rate（Q）dividedbysurface−areaOfthecaninebody（SA）

QI＝Q／SA（l．1）

SAwas calculated asS

FrG．5．lntrapulmonaryshuntratiocalculation．

SA＝0．12W招（1．2）

WhereWisthecaninebodyweight（3）．
The pulmonaryvascular resistance（R）is calcu−
1atedfromPAPmean，LAPme。。，andQmeanby

rateindex），Qlme。n（themean−flow−rateindex），and

Rwere calculated．Thenrepresentativevaluesfor

eachindex，ShowninFigs．9，10，and13，Werede−terminedbyaveraglngfor30min・Additionally，theDuringthese30min，the Qwave−form（pump− wave−fbrmsofQIwerequantitatedbyFourieranal−
OutPut）was recorded，and QIpe。k（the peak−flow− ysISeXPlainedasR）1lows・
R＝（8・0×106）（fnP．ne。n−LAPmean）／Qme。n（1．3）

Theexpresミion．

ウ〇

Ql＝A。＋∑（Ancosnwt＋Bnsinnwt）
n＝1

り．4）

FIG．4．CannuIation methodofthetotalrightventricuIarby−
PaSS．RA，rightatrium；RV，rightventricle；PA，PUlmonaryar−
tery：LA，leftatrium：LV，leftventricle；AO，aOrta・

FIG．6．Blood sample drawingL a．arterialblood sampIe
drawing port；V，VenOUS blood sample drawing port；RA・rightatrium；RV，rightventricle；PA，PUlmonaryartery＝PV，Pulmonaryvein；LV，leftventricle・

Ar∠甘Org（J肛l （7J．ノ2，〃0．ノーJ9ββ72∫．〟A5 月T〃OrOA∧rβ〟．〃0月Jm

trode−methodin ablood−gaS analyzer（Model168．
WhereAoisQImea。，nistheharmonicnumber．An
andBnaretheFouriercoefncients，Wisthefunda−Corning−Medical，U．S．A．）．
Inthis blood−gaS analyzer．thebaseexcess（BE）
mentalangularfrequency，andtistime．ThecoeⅢ−
CientsA。andBnareresoIvedintoaslnglerotatlngiscalculatedfromHb，PH，and［HCO3］4withthe
fbllowlngequationsuggestedbySiggaard−Andersen
VeCtOr．Thatis，
つ〇

QI＝A。＋∑Cncos（nwt＋4）n）（1・5）n＝1WhenCn＝VAn2＋Bn2and4）n＝tanLl卜Bn／（4）

BE＝（10．0143Hb）（［HCO3］−（9．5＋1．63Hb）（7．40−pH）−24．0）（2．1）

Accordingly，BEa and BEv are calculatedfrom
A。）・InFig．8，A。andCn（n≦15）areshown．Inthe
CaSe Ofnonpulsatileflow，2s1（＝120minLl）is LpHa，PaCO2，Hb‥andfromiipHv，PvCOっ，Hb‥
byEq．2．l．respectively．
SubstitutedfbrF（fundamentalfrequency：F＝W／（2Then the fractionaloxygen saturation ofhemo−
7T））inFigs．8Cand8D．
globin（SO2）iscalculatedfromBE，PH，PO2．andT
At the end of30min pumplng，blood samples（b】00d temperature）using the fbllowing equation
Were drawnfromtheoutletofthe pumpandfemr
SuggeStedbyThomas（5）Oralartery．From the oxygen contentin these
Samples，intrapulmonaryshuntratio（s）wascalcu−
SO2＝（n4＋An3＋Bn2＋Cn）／
1ated・Thus the relationships between QI。eak，（n4＋An3＋Dn2＋En＋F）（2．2）
QImean，the pulse flow ratio，2and s could be
Where n＝ −PO2eXP（lnlO（0．48（pH−7・4）−
studied．
The30min experimentalprocess was then re−peated afterthe operatlng fhctorofthe pump wasresettomaintain the newly5elected Qmean，Whichdependsonthecanineleftheartfunctionandonthe
COntrO）ofcircuLatlng bLood volume．Whenthe he−matocrit（Ht）decreased below60％of controI

Values．due to salineinfIation and bleeding、right
VentricuLar bypass pumplng WaS halted．Thus，21

experimentswereperfbrmedwithpumplnglastLng

0．024（T−37）0．00」3BE））．A＝】5，B＝2．045

×10〕．C＝−2×103，D＝2．4×103，E＝3．11×
104，andF＝2・4×106・Thatis，SaOっandSvO2are

Calculated from
pHa，BEa，PaO2，T■■and h■Om
L pHv．BEv，PvO2，T‥byEq．2．2，reSpeCtively．
The oxygen content（02CT）is calculated from
Hb，SO2，andPO2by
O2CT＝（1．34×102）HbSO2＋（3×10▲5）PO2（2．3）

丘om ト6h，Andas befbre，02Clもand O2CTv arecalcu］ated
Tb evaluatethe relationships betweenvariables，
from‥SaO2，PaO2，Hb＝andfrom
SvO2，PvO2，
regression lines and the correlation coefficient
Hb‥byequation2．3，reSPeCtively．Thatis
rangesfor99年conndencelimits werestatisticaJly
Calculatedfromexperimentaldata（Figs．9，10，11，02CTh＝（1・34×102）HbSaO2
and13）．

Intrapulmonaryshuntratiocalculation＋（3×10￣5）PaO2
02CTv＝（1・34×102）HbSvO2（2．4）＋（3×10￣5）PvO2（2．5）
TheintrapuJmonary shunt ratio（s）was calcu−
1atedfromoxygencontentsinthebloodbythelbl一 0っCTcisglVenby
Iowingmethod（Fig．5）．
02CTc＝（1・34×10L2）HbScO2
ThevaluesofHb，pH，PO2，andPCOっweremea−＋（3×10【5）PcO2（2．6）
Suredin blood samples．Tb measure pHv，PvO2，
WhereScO2＝1，andPcO2iscalculatedbythefbl−
andPvCO2，3thebloodsamplewasdrawnfromthe
Outlet（vinFig．6）oftheright ventricularbypass lowing equation

Pump（Orfromthevenacavathroughthecatheter

PcO2＝（760r PAH20−PACO2）（100p HA）／100
introduced via the femoralvein before pumping）．
r2．7）
Tb measure pHa．PaO2，and PaCO2，3the blood
SamPlewasdrawnfromthefemoralartery（ainFig．andPAH20＝47mmHg，PACO2＝40mmHg，and
6）．PO2，PCO2，andpHweremeasuredbytheelec−
HA＝0．5vol．％inthepresentstudy．
Theintrapulmonaryshuntratio（s）isgivenby
2PulsenowTatiois【hequotieptofQ。eakdividedbyQTnean・ThisvalueisunltyWhentheflowISSteady．
3Suffixes‥a‥and‥v
SPeCtive】）′．

．4rげ0／削J75，レroJ．ノ2，Ⅳ仇ノ，ノ9ββdenoteilrterialand venous blood、re−

S＝Qs／qT（2・8）

4［HCO，］isderivedfrompH and PCOzby theHenderson−
Hasselbach sequation．

J八7TRAPU上ルす0八「A尺y∫〃U八7r V∫．P且4斤兄0Ⅵ／一月Arg

乃

RU

Lノハリ

g
Fi

パリh

e

an

Figures7Aand
Thetotalbloodflow（flow−rate，QT）isthemixtしIre
those ofthe control（E oftheinertia］flow
7B show（i）thebackflow
Ofthe oxygenated blood flow（flow−rate，（QT−
latter makes theQs））andthenonoxygenatedbloodnow（now−rate， duetomobilityofthevalves：minor（second）peakofQlin7A．Figures7Cand
Qs）（Fig．6）．Thent

8Cshowthenotcheswithsmallamplitudeandwith
highfrequencyinQIwhicharegeneratedfromthe（QTL Qs）（02CTc）＋Qs（02CTv）＝QT（02C「h）（2．9）

Vibration ofthe rotor．The pulse pressure ofPAP
and the pu］seflow（the diffbrence between peak
and trough flow−rateS）ofQlチre markedlyde−

CombiningEqs．2．8and2．9，

S＝（02CTc−02CTa）／（02CTc02CTv）（2．10）

CreaSedwiththescrewpumpandwiththecentrif−uga］pump．astherecordsinCandDofFig．7dem−

RESULTS

OnStrate．TheseresuJtsarequantitativelyexpressed

Placement pump）duringtotalrjghtventricularby−

bythesmallmagnitudesofharmoniccontent（har−monicnumber＞1）inCandDofFig，8．Especia11y
in the centrifugalpump，eVery magnitude（har−PaSSWiththreetypesofbLood pumpare shownin

monicnumber＞1）wasunderthenoiselevelofthe

Some typicaltraces ofPAP，LAP，Ql（Ofpump−
OutPut），and V（Shown only for the positive dis−Fig．7．TheharmoniccontentsofQlfbreachcorre− SyStem．
From animalexperimentsin these21dogs，92
SPOndingcase are shownin Fig．8，along＼〜′iththe
COntrOIQl．1nFig．8，theheightofeachbarrepre− datapolntSWerereCOrdedandareshowninFigs．9，

SentStheaveragemagnitudeoftheharmonic．The

10．andll．The meanflow−rate WaS COntrOlled toO−harmonic represents theformofQltrulyvarieswitheachofthethreetypes

Within10％variationofthetargetvalueinthepre−
Ceding30min for these data，Where PAPmea。，
LAPmean，T，and Ht were18±6mmHg，7±5

Ofbloodpump・InthepistonTbeIlowspump・Ql，eak

mmHg，33±2OC，and30±8％（mean±1stan−．

isvariedwithER（COmPareAwithBinFig．7）．Thedarderror），reSPeCtively．
Figure9showssasafunctionofQIpeak・Thein−harmonic contents ofQIinB ofFig．8resembles
A mmHg

D mmHg

B mmHg．￣＼・＿一一−−−−■＼＿、一C mmHg
20
PAPノ∨い√′叫ハへ〜−−

ノmjn−1m−2

20
乱Ⅰ

ノ．mjn￣1m￣2

0

■

0

Tjme lsm l O qノ

V

100
90

βん 0 0mヱ

110＼／−・／＼、ノノ＼／

LAP

10

u n

Tうme

l＝il∫ キ

ls

L ：

司

Tjme

ls

Time

1 s

FIG．7．SomeexamplesofsimuItaneoustracesofpressureandf10Wduringtotalrightventricularbypassvviththreetypesof
PUmPSrAandB，Piston−ber10WStyPe（A，ER＝7・5mm；B，ER＝2．5mm）；C，SCreWtyPe；D，Centrifugaltype・

ArJ甘Org（一円∫，VoJ．ノ2，〃0．ノ，ノ9ββ74∫．〃A∫〃JルタOrOAノVβ〃，ルす0月Jm■ソL

7∈・1．∪サ∈︑．Hd▲ソL

7∈．t．∪盲︑．1α

T∈．TU革︑．tけ

01Z 3 4 5 6 7 8 9101
Harmonjc nul¶ber，∩Harmonjc number．n012 3 4 5 6 7 8 9101112131415【armonjc nuMber，∩

2

T∈TU芸・︑．1d▲ソL㌻∈．TU盲ヽ．；6 7 8 9101112131415
Harmonjc number．∩

012 3 4 5 6 7 8 9101112131415
Harmonjc nu【1ber．n

FIG．8．HarmoniccontentsofQlfromA，B，C，andDofFig．7areshowninA，B，C，andDinthisfigure，reSPeCtive
eachbarrepresentsthemeanmagnitudeofeachharmonic・Verticallinesaroundthemeanrepresentthestandarderrorofthemeanoverthe30minperiod．TheharmoniccontentsofQIcontroIvaluesareshowninE，Whereverticallinesaroundthe
representthestandarddeviation．Thenoiseleve10fthesystemisindicatedbythehorizontalbrokenlines．

trapuLmonaryshuntratiorangesbetweenO．095andO．392with no clear relation（LO．3＜ー＜0．3）toQI，eak，Whichvariedbetweenl・1and17・01min▼1
m−2．

Figure10shows sasafunctionofQImean．The
intrapulmonary shunt ratio does not increase as

and thelattergrouplnCludesdatawiththecentrif−
ugalpumporwith the screwpump．Theintrapul−

monaryshuntratioiskeptwithintherangeofcon−
troIvalues fbr6h，eVenin the nonpulsatileflow
grOup・

Figure13showsRasafunctionofthepulseflow

ratio．ThisngureshowsthatinseveralcasesRreT
QImeandecreasesfrom2．5toO．81minTlm．2，and
revealsnocleardifftrenceamongthethreegroupmainsverYSmallevenwhenQ。eak／Qmeanisapproxi−

Ofdata（dividedaccordingtothepumptypes）evenmately unlty（which means quasi−Steady now），al−intherangeofsmallQlmean．

thoughafainttrendisshownthatRincreaseswith

Figurellshowssasafunctionofthepulseflow
ratio．Again，SrangeSWithnoc）earrelation（−0．3

Q，eak／Qmeandecrease・＜r＜0．2）to the pulse ratio，Whichis varied be−
tweenl．Oand13．6．

Figure12showssasafunctionofpumplngtime
Wheredataaredividedintotwogroups．Oneisthepulsatilenowgroup，inwhich（Q，eak／Qmean）≧2・5

andQlpeak≧4・01min￣1mL2；andtheotheristhe
nonpulsatileflowgroup，享nwhich（Q，eak／Qmea。）＜2・5andQI，eak＜4・〔Ilmln￣1m￣2・TheformergrouplnCludesdatawiththepiston−bellowspump，

ArげOr押〃．1，Vの／．ノ2，〟〃．ノ，ノ9ββ

InFigs．9，10，11，12，and13．eachcontroIvalue
Ofs，Qlpeak，Qlmean，Q。eak／QmeanlOrRisshownad−
jacenttotheyaxisbytheclosedcircle（mean）Land
thebar（±1standarddeviation），reSPeCtively．
DISCUSSION

Theefftctsofpulsatileornonpulsatilebloodnow
On Circulatory systems have been previously dis−
CuSSed based upon the cardiopulmonary bypass

75

JノVTソ？APL7上〃OM尺1′∫〃UノVr V∫．P丘■A〟F上Olγ一月A7「gLOL︼uOU

10

5

15

：

壬

2

1

飢peak，ノ，mjn−1m一三

QIme。。，ノ・mう∩￣1▲m￣2

LcontroI

FIG・9・rntraPulmonaryshuntratio（S）a予afunctiono†Q［p。akL
0・3＜（く0・3（thecorreIationcoefficI？ntrangeWjth99％
COn†idencelimit：thesamekindofrangelSShowninFigs．10，
11，and13）．C，Piston−be owspump；△．centrifugaIpump：▲，

COntrOI
FIG．10．lntrapulmonary shunt ratio（S）as a function of
Qlm。a。．0．03くrく0．5．0，Piston−belJowspump：△，Centrif−
UgatPumP；▲，SCreWPUmPL

SCreW PUmP，

Ofrapidqjectionasanjmportantelementofpulse．
andiso］atedorganperfusionexperimentaJpreparaT

1nthepresent study，Q。e。kispickeduptoquanti−

tions（6）．The possible effects ofpulsatile bloodflow on circulatory systems are（a）the controlof
distribution ofthe blood flow（including anasto−
motic andlymphatic flows）and（b）the enhance−
mentofmetabolites−tranSfer（7）．ThefbrmermighttatepuJsatilitywithfnxedat120minrl．Asstatedbe derivedfrom visco−elastic properties of blood

befbre，intotalventricularbypass，Qme。nWaSequal
tothecardiacoutput，WhileQ。eakCOuldbevariedto

PrOduce various pulsatile conditionsdependingon
Which pump was used．The harmonic contents of
QlinFig．8Bresemblethoseofacontroldogwith

VeSSels，from nonTNewtonian behaviour ofblood，and from the vasomotor tone contro】1ed by the

nervous system．Thelatter might be related to amixlng effect．which reduces the diffusion resis−
tance ofmetabolite pathways．These ef托cts havebeenstudiedinanimaltestsuslngrightventricular、
1eft ventricular，Or biventricular bypass．Some

Studieshavereportedthatthebloodflowdistribu−
tionsinorgans（e．gリinlhekidney）aremorephysi−
0loglCa）under pulsati】e than under nonpulsatile
now along with organ（e．g．，renal）functions，andaIsothatthe peripheralresistancei5Sma11erunderpulsatilethanundernonpulsatilenow（8，9）．Onthe
Other hand，a Calf s totalcircuJation had been

maintainedingoodphysiologlCalstatusbr99days
undernonpulsatileconditions（10）．1notherwords，
some datafrom these studies demonstrate advan−
tagestopulslngthebloodflow，Whileothersdonot．

Tb make any discussion clear on this subject，
Pulsatilityofbloodflowhas tobequantitatedand
theef托ctofpulsatilityhastobequanlitative］yre−

Lated to eachpolnt Ofthe circulatory system．For
example，Jacobsetal．（9）lookedattheinitialphase10ape。k／軋e。∩： 壬t

COntOI

FIG．11．lntrapulmonary shunt ratio（S）as a function of
Qpeak／Qmean：0・3くrく0・2・○・Piston−bellowspump；△】Cen−
trifugalpump；▲，SCreWPUmP・ArJげ org〟〃右V（フJ．ノ2，〃0．ノ，ノ9ββ．†．〃．1．†〃‖J（）r（）．1．＼ J）〃‥り（）〃／I■．1

76

tlnguished carefully，because the perfectLy steadyflowis hardly realizedin generalfluidcirculation，muchlessin blood circulations．Peripheralflows
WithQ。eak／Qmea。＜2・5areestimatedtobequasi−

Steady．becausevibrationsofsmallamplitude（OrOf

highfrequency）atthepumpoutletaresmoothedby
the viscoelastic compliance ofblood vessels（12）．
Accordingtothisclassification，theQ wave−forms

什omeitherthecentrifugalorscrewpumpareclas−
Sifiedintothenonpulsatilegroup．
1nthe present study，Qmea。is controllednotby

the transfusion of homogeneous blood but by the
SuPPlyofthe saline solution，inordertominimize
the otherbiologlCaleffbcts on theintrapulmonary
COntrOI

Z

4

6

Purnplng tirne，hours
FIG．12．Intrapurmonary shunt ratio（S）as a function of
PUmPIngtime．0．pulsatiIef10W；＋，nOnPuJsatileflow．

Shunt ratio．In the present experiments，dataindi−
CatenOClearrelationbetweensandHt（17−50％），
which means that this transfusion does not havemuch efftcts on s．

Theresultsinthepresentstudyshowthatevenin
thenonpulsatileflow，1・0＜（Qpeak／Qmean）＜2・5，thebloodis welloxygenated so that theintrapul−
naturalheart．which also were reported by Patel（11）．

monaryshuntratioiswithinthecontroIvalue（Fig．
11），While pulsatility enhances gas transftrin themembrane oxygenator（the artificiallung）（13）．

Although the distinction between pulsatile andThese results do not completely negate the possi−
nonpu］satilegroupswasnotquantitativelydefinedin previous studies，authors arbitrarily classified bility that pulsatility enhances gas transfer in thethesetwogroupsaccordingtothepulseflowratio

Pulmonarymicrocirculation，Wherepu）satilecondi−（Q。eak／Q，n。。n）：Q。eak／Qmean≧2・5in thepulsatilegroupland Q。eak／Qmea。＜2・5in the nonpulsatile

Ofthepulsefromtheleftatrium，duetothe bron−tionmightexistowlngtOthebackwardpropagationgroup，Especially，nOnPulsatiJenowshouldbedis− Chialpulse orthe resplratOryPulsein thepresent

experiments，Theseresultsmaybeattributedtothe

largeallowancesofthe naturallung，Ofwhichgas−transftr−membraneismuchthinnerandlargerthan
thatofartificiallungwhichisavailabletoday．This

tendencydoesnot changewhenQIrneanis smaJlin
1．S・ゴー∈・gもLX

Fig．10，although the fbrmer studies have shownthat the pulse has good effect on systems when
QImeanissmall（6）．SmallvalueofQImea。inFig．10（which mightindicate heart failure）does not ad−

VerSelyaffecttheexperimentaldesign，becausethe
bloodoxygenationismeasuredinrelationtoQIpeak
Whichismechanica】7ycontrolledbyrightheartby−

T−1一丁−−⊥

LOL︸UO︺

pass pumplng．Theresultin Fig．13alsoindicatesthat pulmonary vascular resistanceis ab】e to be

kept smalleven under nonpulsatile now，WhichdoesnotagreewithClarke sstudy（8）．

Thisstudydemonstratesthattheintrapulmonary
ShuntratioisabletobeheldintherangeofcontroL

ape。k／軋e。∩㍍。1‥FIG．13．Pulmona「yvascularresistance（R）asafunction of
Qpeak／Qmean・0・6＜「＜−0・04・○，Piston−beJrowspump；△，
Centrifugalpump；▲、SC「eWPumP．

A畑「Orビ〟／7†．t oJ．／2，〃0．J．／9ββ

Value even with the peak−flow−rateindex smaller
than4．01min−1mJ2，andthatnonpulsatilepump

areavailablefbrthetotalrightheartbypasspumps．
Acknowledgment：TheauthorsthankHiroshiIshikawa
and MasakiSohmafortheirtechnicalassistance．

J」ⅣmAf，U⊥〃0」ⅣA月y5 〃U〃rl／r∫．P且4〟FLOW一月ArE

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77

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