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简介：Locomotionability,efficiencyandreliabilityarekeytargetsforagoodrobot.Thelinkagemechanismforrobotlocomotionisadiscontinuous-constraintmetamorphicmechanism.Herewesetupequationstopresentthediscontinuous-constraint,pointoutthatdrivingandcontrollingarethekeypointstoimprovetheperformanceandefficiencyofthelinkagemechanism.Inspiredbycontrollingstrategyofthemotornervoussysteminperipheralvertebraetothelocomotion,wedrawoffmotorcontrolanddrivestrategy.

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简介：

简介：UHMWPEcompositesreinforcedwithBovineBoneHydroxyapatite(BHA)indifferentcontentswerepreparedbyheatpressingformationmethod.AhipjointwearsimulatorwasusedtoinvestigatethebiotribologicalbehaviorofUHMWPE/BHAcompositeacetabularcupsagainstCoCrMoalloyfemoralheadsinbovinesynovialubricationat37±1℃.ItwasfoundthattheadditionofBHApowdertoUHMWPEcanimprovethehardnessandcreepmodulusofUHMWPE/BHAcomposites,anddecreasetheirwearratesunderbovinesynovialubrication.WhenthecontentofBHAfillerparticleswasupto30wt%,UHMWPE/BHAcompositesdemonstratedthewelldesignperformancesofthesurfaceandbiotribologicalproperties.Fatigue,ploughingandslightadhesivewearwerethemainwearmechanismsforUHMWPEanditscomposites.Inaddition,thesizesofwearparticlesbecamelargerwithanincreaseinBHApowderaddition.TheseresultssuggestthatBHAfillerisadesirablecomponenttoincreasethewearresistanceofUHMWPE/BHAcompositesforbiomedicalapplications.

简介：Abiomimetichipjointsimulatorthatcanbeusedtoevaluatetheoutcomeofthecementedtotalhipreplacementhasbeendesigned,manufacturedandevaluated.Thesimulatorproducesmotionintheextension/flexionplane,withasockettorotateinternal/externally.Atthesametimeadynamicloadingcycleisapplied.Avalidationtestwasperformedonacementedfemoralstemwithinanovelcompositefemur.Thebonequalityhasastrongeffectonthestemmigrationandontheintegrityoftheinterfaces.Themigrationofthestemisacombinationof3-Dtranslationandrotationofthestem.Underthesameloadingconditions,weakboneallowsmorestemmigrationthanstrongbone.Thereisagreatdecreaseinthestrengthofthestem-cementinterfaceafterthedynamictest,andtheweakbonecompositeexhibitedagreaterreductionininterfacialstrengththanthestrongbonecomposite.Thedecreaseoftheinterfacialstrengthindicatesthattheprimarybondingbetweenthestemandthecementmantlehaddeterioratedandtheintegrityofstem-cementinterfacewasdamaged.Thestudydemonstratesthevalueofusingahipjointsimulatortoinvestigatestemmigrationandinterfaceintegritywithinthecementedhipreplacement,suggestingthatmethodcanbeusedforinvitroevaluationofthebiomaterialsusedinthecementedhipreplacements.

简介：Inthisstudyalumbarspinalfusionanimalmodelisestablishedtoassesstheeffectofspinalfusioncage,andexploretheminimumarearatiooftitaniumcagesectiontovertebralsectionthatensuresbonehealingandbiomechanicalproperty.Lumbarcorpectomywasconductedbyposterolateralapproachwithtitaniumcageimplantationcombinedwithplatefixation.Titaniumcageswiththesamelengthbutdifferentdiameterswereused.Afterimplantationoftitaniumcages,theprogressofbonehealingwasobservedandthebonebiomechanicalpropertiesweremeasured,includingdeformationanddisplacementinaxialcompression,flexion,extension,andlateralbendingmotion.Thefactorsaffectingtheinvivogrowthofspinesupportingbodywereanalyzed.Theresultsshowthatthearearatiooftitaniumcagesectiontovertebralsectionshouldreach1/2toensurethebonehealing,sufficientboneintensityandbiomechanicalproperties.Somebonehealingindicators,suchasBMP,suggestthatthereisarelationshipbetweenthepeaktimeandthepeakvalueofboneformationandmetabolismmarkersandthebonehealingstrength.