The Design and Development of an Intelligent Atraumatic Laparoscopic Grasper

245 Pages·2015·19.96 MB·English

The Design and Development
of an Intelligent Atraumatic
Laparoscopic Grasper
SubmittedinAccordancewiththeRequirementsfortheDegreeof
DoctorofPhilosophy
TheUniversityofLeeds
InstituteofFunctionalSurfaces
SchoolofMechanicalEngineering
Louise Russell
April 2015
Thecandidateconfirmsthattheworksubmittedisherown
andthatappropriatecredithasbeengivenwherereferencehas
beenmadetotheworkofothers
Thiscopyhasbeensuppliedontheunderstandingthatitiscopyright
materialandthatnoquotationfromthethesismaybepublished
withoutproperacknowledgement
(cid:13)c 2015TheUniversityofLeedsandLouiseRussell

Acknowledgements
I would firstly like express a huge thanks to Prof. Anne Neville, for her tireless support
and encouragement throughout the project. Her enthusiasm and patience has helped me to
maintainapositiveoutlook. IamalsoimmenselygratefultoDr. PeterCulmerforhisendless
adviseandknowledgeofthedifferentareasofmyproject. Ithasbeenafantasticopportunity
andwouldnothavebeenpossiblewithoutthem.
I would also like to show my respect and appreciation to Jenifer Barrie for being hard
workingandcommittedtoherprofessionwhileworkingwithmetoprogressinourindividual
projects. Her collaboration has added a lot to my work and it has been a pleasure to work
withher.
ThankyoutoSurgicalInnovationsLtd. andMikeWhite,directorofproductdevelopment,
forprovidingessentialindustrialknowledge.
I wish to extend my gratitude to Prof. David Jayne and Adrian Hood for their expertise
andadvisethroughouttheproject,andenablingmanyaspectsoftheprojecttobecarriedout.
TheMechanicalEngineeringtechniciansandstaffhaveprovedinvaluable,fortheiradvise
andhelpthroughthedifferentstagesoftheproject. Thankyou.
Abigthankstomyfellowcolleagues,thesurgicaltechnologiesgroupandmycollegesin
office 2.47. It has been a fun four years, in which I have gained new friends, many of whom
willremainasfriendsfortheyearstocome.
ThankyoutomyMum,DadandsisterJoanneforalltheirencouragementandreassurance.
I would also like to thank my grandparents who, even though they were unable to see me
completemyPhD,alwaysencouragedmetoworkhardinwhateverareaoflifeIpursued.
Finally I would like to thank my husband Christopher Russell who has been my biggest
support throughout my academic studies. He is an inspiration to me and gave me a huge
amountofmotivationwhenthingsgottough.
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iv
Abstract
A key tool in laparoscopic surgery is the grasper, which is the surgeon’s main means of
manipulating tissue within the body. However inappropriate use may lead to tissue damage
and poor surgical outcomes. This thesis presents a novel approach to the assessment and
prevention of tissue damage caused by laparoscopic graspers. The research focusses on
establishing typical grasping characteristics used in surgery and thus developing a model
of mechanically induced tissue trauma. A review explored the state-of-the-art in devices
for measuring surgical grasping, tissue mechanics, and damage quantification to inform the
research.
An instrumented grasper was developed to characterise typical surgical tasks, enabling
the grasping force and jaw displacement to be measured. This device was then used to
quantitatively characterise grasper use in an in-vivo porcine model where the device was
usedtoperformorganretractionandmanipulationtasks. Fromthiswork,therangeofforces
and the grasping times used in certain tasks were determined and this information was used
to guide the rest of the study. The in-vivo investigation highlighted a need for grasping in a
controlledenvironmentwherethetissue’smechanicalpropertiescouldbestudied.
A grasper test rig was designed and developed to provide automated controlled grasping
of ex-vivo tissue. This allowed the mechanical properties of tissue to be determined and
analysed for indications of tissue damage. A series of experimental studies were conducted
with this system which showed how the mechanical response of tissue varies depending on
theappliedgraspingforcecharacteristics,andhowthisisindicativeoftissuedamagethrough
comparison to histological analysis. These data were then used to develop a model which
predicts the likelihood and severity of tissue damage during grasping, based on the input
conditions of grasping force and time. The model was integrated into the instrumented
grasper system to provide a tool which could enable real-time grading and feedback of
graspingduringsurgery,orbeusedtoinformbestpracticeintrainingscenarios.
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Table of Contents
ListofFigures xi
ListofAbbreviations xvii
1 Introduction 1
1.1 MotivationfortheProject . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
1.2 AimsandObjectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.1 Aims . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.2.2 Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 ContributionsoftheWork . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.4 ThesisStructure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
2 Literature Review: Minimally Invasive Surgery Techniques, Bio-Mechanical
TissueCharacteristicsandStateoftheArtGrasperDesignsandDevelopments 5
2.1 BackgroundtoMinimallyInvasiveSurgery . . . . . . . . . . . . . . . . . . 5
2.1.1 CurrentMISTechnology . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.2 DevelopmentsofFutureMISTechnology . . . . . . . . . . . . . . . 9
2.2 MinimallyInvasiveSurgicalGraspers . . . . . . . . . . . . . . . . . . . . . 12
2.2.1 GrasperDesigns . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
2.2.2 GrasperMechanismAnalysis . . . . . . . . . . . . . . . . . . . . . . 15
2.2.3 LaparoscopicGrasperDesignImprovements . . . . . . . . . . . . . . 17
2.3 AbdominalTissueAnalysis . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.3.1 RigDesignsUsedtoInvestigateTissueCharacteristics . . . . . . . . 19
2.3.2 ModellingtheMechanicalPropertiesofTissue . . . . . . . . . . . . 21
2.3.3 TheMeasurementofTissueDamage . . . . . . . . . . . . . . . . . . 28
2.4 CurrentResearchDevelopmentsinMISDevices . . . . . . . . . . . . . . . . 31
2.4.1 Force/PressureSensors . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.4.2 DevicestoMeasureMISIn-vivoTaskParameters . . . . . . . . . . . 35
2.4.3 DevicesforDeterminingTissueCharacteristics . . . . . . . . . . . . 38
2.4.4 TactileFeedbackTransducers . . . . . . . . . . . . . . . . . . . . . . 39
2.4.5 MISTissuePalpationDevices . . . . . . . . . . . . . . . . . . . . . 40
2.4.6 MISTrainingTechniques . . . . . . . . . . . . . . . . . . . . . . . . 41
2.5 SummaryofLiteratureReview . . . . . . . . . . . . . . . . . . . . . . . . . 44
2.6 TheGapsinKnowledge . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 46
3 Design,Development,andTestingoftheInstrumentedGrasper 49
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viii TABLEOFCONTENTS
3.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
3.2 InstrumentedGrasperDesignSpecification . . . . . . . . . . . . . . . . . . . 49
3.3 SensorLocationConsiderations . . . . . . . . . . . . . . . . . . . . . . . . . 50
3.4 MathematicalModellingofScissorLinkageMechanism . . . . . . . . . . . 53
3.4.1 FreeBodyDiagramandAssumptions . . . . . . . . . . . . . . . . . 53
3.4.2 ForcePropagationModelDerivation . . . . . . . . . . . . . . . . . . 54
3.4.3 JawAngleModelDerivation . . . . . . . . . . . . . . . . . . . . . . 56
3.4.4 ModellingResultsfortheSpecificGrasperGeometry . . . . . . . . . 58
3.5 GrasperModelValidation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.5.1 AngleValidation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
3.5.2 ForceTransmissionValidation . . . . . . . . . . . . . . . . . . . . . 62
3.5.3 ValidationConclusion . . . . . . . . . . . . . . . . . . . . . . . . . 66
3.6 DevelopmentoftheInstrumentedGrasperPrototype . . . . . . . . . . . . . . 67
3.6.1 DesigningtheInstrumentationModule . . . . . . . . . . . . . . . . . 67
3.6.2 InstrumentedGrasperHardware . . . . . . . . . . . . . . . . . . . . 69
3.6.3 InstrumentedGrasperData-LoggingProgram . . . . . . . . . . . . . 72
3.6.4 ValidationoftheLoadcellandPotentiometerMeasurements . . . . . 75
3.7 In-vivoTestingwiththeInstrumentedGrasper . . . . . . . . . . . . . . . . . 78
3.8 In-vivoOrganManipulationTesting . . . . . . . . . . . . . . . . . . . . . . 78
3.8.1 MethodologyofIn-vivoOrganManipulation . . . . . . . . . . . . . 78
3.8.2 In-vivoLaparoscopicTestingSet-up . . . . . . . . . . . . . . . . . . 79
3.8.3 In-vivoOrganManipulationResults . . . . . . . . . . . . . . . . . . 80
3.9 In-vivoColonForceGraspTesting . . . . . . . . . . . . . . . . . . . . . . . 84
3.9.1 MethodologyofIn-vivoColonGrasping . . . . . . . . . . . . . . . . 84
3.9.2 In-vivoOpenSurgeryGraspingSet-up . . . . . . . . . . . . . . . . . 85
3.9.3 In-vivoColonGraspingResults . . . . . . . . . . . . . . . . . . . . . 85
3.10 ConcludingRemarksAbouttheInitialDesign . . . . . . . . . . . . . . . . . 88
3.11 RedevelopmentoftheInstrumentedGrasperPrototype . . . . . . . . . . . . 89
3.11.1 RedesigningtheInstrumentationModule . . . . . . . . . . . . . . . 89
3.11.2 InstrumentedGrasperHardware . . . . . . . . . . . . . . . . . . . . 90
3.11.3 InstrumentedGrasperData-loggingProgram . . . . . . . . . . . . . 93
3.11.4 ValidationoftheLoadcellandEncoderMeasurements . . . . . . . . 94
3.12 ConcludingRemarksAbouttheInstrumentedGrasperRedesign . . . . . . . 96
3.13 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 96
4 LaparoscopicGrasperTestRig 99
4.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 99
4.2 DesignSpecificationfortheTestRig . . . . . . . . . . . . . . . . . . . . . . 99
TABLEOFCONTENTS ix
4.3 DevelopmentoftheInitialTestRigPrototype . . . . . . . . . . . . . . . . . 100
4.3.1 DesignoftheTestRigStructure . . . . . . . . . . . . . . . . . . . . 100
4.3.2 HardwareSet-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
4.3.3 ControlandData-loggingProgram . . . . . . . . . . . . . . . . . . . 107
4.3.4 ValidationoftheMeasurementsandControlSystem . . . . . . . . . 109
4.4 ConcludingRemarksabouttheInitialDesign . . . . . . . . . . . . . . . . . 112
4.5 RedevelopmentoftheLaparoscopicGrasperTestRig . . . . . . . . . . . . . 113
4.5.1 DesignoftheTestRigStructure . . . . . . . . . . . . . . . . . . . . 113
4.5.2 HardwareSet-up . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116
4.5.3 TheDesignoftheLabVIEWInterface . . . . . . . . . . . . . . . . . 116
4.5.4 TheActuatorControllerSerialCommunications . . . . . . . . . . . . 118
4.5.5 TheLabVIEWStateMachineStructureandControl . . . . . . . . . . 120
4.5.6 ValidationoftheActuatorPositon . . . . . . . . . . . . . . . . . . . 121
4.5.7 TheOptimisationoftheControlLoop . . . . . . . . . . . . . . . . . 123
4.6 ConcludingRemarksabouttheFinalDesign . . . . . . . . . . . . . . . . . . 125
4.7 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125
5 Ex-vivoTissueDamageInvestigation 127
5.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 127
5.2 LaboratorySetupforEx-vivoTissueTesting . . . . . . . . . . . . . . . . . . 127
5.3 DataAnalysisMethodology . . . . . . . . . . . . . . . . . . . . . . . . . . . 129
5.4 TissueMechanicsInvestigation . . . . . . . . . . . . . . . . . . . . . . . . . 130
5.4.1 TissueMechanicsMethodology . . . . . . . . . . . . . . . . . . . . 131
5.4.2 TissueMechanicsResults . . . . . . . . . . . . . . . . . . . . . . . . 133
5.5 HistologyDamageInvestigation . . . . . . . . . . . . . . . . . . . . . . . . 139
5.5.1 HistologyTestingMethodology . . . . . . . . . . . . . . . . . . . . 139
5.5.2 MechanicalModellingResultswithSupportingHistology . . . . . . 142
5.6 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150
6 IntelligentGrasperDamagePrediction 153
6.1 Introduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153
6.2 DevelopmentoftheTissueDamageAlgorithm . . . . . . . . . . . . . . . . . 153
6.3 ImplementationoftheTissueDamageAlgorithm . . . . . . . . . . . . . . . 158
6.3.1 Post-operativeAnalysisofTissueDamage . . . . . . . . . . . . . . . 158
6.3.2 Real-timeAnalysisofTissueDamage . . . . . . . . . . . . . . . . . 159
6.4 Conclusion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 161
7 Discussion 163
7.1 MeasuringIn-vivoManipulationandGrasping . . . . . . . . . . . . . . . . . 163
x TABLEOFCONTENTS
7.2 SimulatedEx-vivoTissueGrasping . . . . . . . . . . . . . . . . . . . . . . . 165
7.3 CharacterisingtheMechanicalResponseofTissue . . . . . . . . . . . . . . . 167
7.4 DamageGradingUsingMechanicalResponseData . . . . . . . . . . . . . . 169
7.5 FinalConclusions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171
7.5.1 OverallConclusions . . . . . . . . . . . . . . . . . . . . . . . . . . 171
7.5.2 PracticalSignificanceinSurgery . . . . . . . . . . . . . . . . . . . . 172
7.5.3 ProjectInspiration . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
7.6 FutureRecommendations . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173
7.6.1 AssessmentofRetractionForces . . . . . . . . . . . . . . . . . . . . 173
7.6.2 TissueMechanicsTransitionInvestigation . . . . . . . . . . . . . . . 175
7.6.3 UnderstandingandImprovingtheGrasperMechanism . . . . . . . . 175
7.6.4 GrasperManufacturingStandard . . . . . . . . . . . . . . . . . . . . 176
7.6.5 IntegrationintoRoboticSurgery . . . . . . . . . . . . . . . . . . . . 176
References 179
AppendixA 200
AppendixB 215