Frederico Gutierrez, Mitul Saha Yong Song and Anna Timbie Guidant mentors: David Wolf-Bloom, Stephanie Szobota Stanford mentors: Dr. Charles Taylor, Chris Elkins February 10, 2003 Project Plan Presentation

2/10/03ME Guidant Corporation, Vascular Innovations Guidant is a leader in the design and development of cardiovascular medical products

2/10/03ME Motivation The development of medical devices is limited by the ability of designers to evaluate them before human use.

2/10/03ME Preclinical Test Methods  Animal studies ExpensiveExpensive Unfeasible for high-volumeUnfeasible for high-volume Ethical considerationsEthical considerations  Simple plastic models  Cannot replicate in vivo conditionsin vivo conditions Human disease stateHuman disease state

2/10/03ME Synthetic Arterial Model Simplified human “knee to neck” anatomySimplified human “knee to neck” anatomy Tissue simulating materialsTissue simulating materials Perfused with water or blood from pumpPerfused with water or blood from pump

2/10/03ME SAM  Benefits FluorcompatibleFluorcompatible Modular, “plug-n-play”Modular, “plug-n-play” PortablePortable  Limitations Static flow (roller pump)Static flow (roller pump) Static heartStatic heart No respiratory movementNo respiratory movement

2/10/03ME Project Goals  To improve the clinical realism of the Guidant SAM by incorporating new design features Pulsatile flow through the vasculaturePulsatile flow through the vasculature Coronary Artery and Heart Wall MotionCoronary Artery and Heart Wall Motion Respiratory MotionRespiratory Motion  Provide Guidant with a tool for product testing and physician training

2/10/03ME Project Scope Heart wall motion and pulsatile flow need not be coupledHeart wall motion and pulsatile flow need not be coupled Anatomical realism of internal heart structure not necessaryAnatomical realism of internal heart structure not necessary Flow rate and pressure within 10% of published valuesFlow rate and pressure within 10% of published values

2/10/03ME Deliverables 1.System for regulation of pulsatile flow from Harvard Pump through arterial model 2.Prototype of mechanism to produce heart wall motion 3.System for synchronization of heart “beat” and pulsatile flow 4.Prototype of mechanism to produce diaphragm motion

2/10/03ME Benchmarking  Vascular Models Consist of Rigid ElementsConsist of Rigid Elements No Plug-n-Play AbilitiesNo Plug-n-Play Abilities Does Not Incorporate Pulsatile FlowDoes Not Incorporate Pulsatile Flow

2/10/03ME Benchmarking Beating Heart Models – The Chamberlain Group Training model for beating heart surgery Electrically powered Uses Pneumatic Coils to Create Motion Suturable Exterior Skin Not Fluorocompatible

2/10/03ME Benchmarking  Mechanical Left A/V model Provides realistic flow and pressures of the left A/VProvides realistic flow and pressures of the left A/V Can be used to calibrate flow for mechanical heartsCan be used to calibrate flow for mechanical hearts Not anatomically realisticNot anatomically realistic

2/10/03ME Related Technology  Harvard Pump Generates Pulsatile Flow Adjustable Flow Rates and Stroke Volume Physiologically Accurate Motion

2/10/03ME Related Technology  Flexible Molding Casting Polyurethane and Silicone MaterialsCasting Polyurethane and Silicone Materials Relatively low prototyping costRelatively low prototyping cost Materials range from Hardness of (Shore A)Materials range from Hardness of (Shore A) Flexibility of up to 1000% original sizeFlexibility of up to 1000% original size

2/10/03ME Critical Design Requirements  Functional

2/10/03ME Critical Design Requirements  Functional Pulsatile flow through thePulsatile flow through thevasculature

2/10/03ME Critical Design Requirements  Functional Pulsatile flow through thePulsatile flow through thevasculature Realistic flow rate and pressure in the major arteriesRealistic flow rate and pressure in the major arteries

2/10/03ME Critical Design Requirements  Functional Pulsatile flow through thePulsatile flow through thevasculature Realistic flow rate and pressure in the major arteriesRealistic flow rate and pressure in the major arteries Heart wall motionHeart wall motion

2/10/03ME Critical Design Requirements  Functional Pulsatile flow through thePulsatile flow through thevasculature Realistic flow rate and pressure in the major arteriesRealistic flow rate and pressure in the major arteries Heart wall motionHeart wall motion Synchronization ofSynchronization of Pulsatile flow and Heart wall motion

2/10/03ME Critical Design Requirements  Physical Fluoro-compatibleFluoro-compatible Approximate size and shape of human heartApproximate size and shape of human heart Interface with aortic tree and coronary arteriesInterface with aortic tree and coronary arteries

2/10/03ME Critical Design Requirements  Physical Fluoro-compatibleFluoro-compatible Approximate size and shape of human heartApproximate size and shape of human heart Interface with aortic tree and coronary arteriesInterface with aortic tree and coronary arteries

2/10/03ME Critical Design Requirements  Physical Fluoro-compatibleFluoro-compatible Approximate size and shape of human heartApproximate size and shape of human heart Interface with aortic tree and coronary arteriesInterface with aortic tree and coronary arteries

2/10/03ME Critical Design Requirements  Physical Fluoro-compatibleFluoro-compatible Approximate size and shape of human heartApproximate size and shape of human heart Interface with aortic tree and coronary arteriesInterface with aortic tree and coronary arteries

2/10/03ME Desirables Diaphragm movementDiaphragm movement Adjustable heart rate ( bpm)Adjustable heart rate ( bpm) Adjustable vessel pressureAdjustable vessel pressure Easy “plug-n-play”Easy “plug-n-play” Simulation of cardiovascular diseaseSimulation of cardiovascular disease

2/10/03ME Expected Difficulties Achieving accurate pressure and flow through entire modelAchieving accurate pressure and flow through entire model Molding of flexible heartMolding of flexible heart Leakage due to material incompatibilitiesLeakage due to material incompatibilities Air trapped in modelAir trapped in model System integration and controlsSystem integration and controls

2/10/03ME Timeline (Winter) 2/2 ~ 2/21Design Beating Heart2/2 ~ 2/21Design Beating Heart 2/10 ~ 2/19Analytical Flow Model2/10 ~ 2/19Analytical Flow Model 2/10 ~ 2/19Design Lab-View System2/10 ~ 2/19Design Lab-View System 2/28 ~ tbdTest and Tune Flow Model2/28 ~ tbdTest and Tune Flow Model 2/19 ~ 3/1Heart Critical Function Prototyping2/19 ~ 3/1Heart Critical Function Prototyping 3/1 Select Heart Design3/1 Select Heart Design 3/10 ~ 3/14 Final Presentation & Report3/10 ~ 3/14 Final Presentation & Report

2/10/03ME Timeline (Spring) Beating Heart PrototypingBeating Heart Prototyping Diaphragm Motion Design and PrototypingDiaphragm Motion Design and Prototyping Total System Integration and TestingTotal System Integration and Testing Integrate Into SAMIntegrate Into SAM Final System TestingFinal System Testing Final Presentation & ReportFinal Presentation & Report

2/10/03ME Individual Responsibilities Eric ► Flow Modeling, Material Research, Molding Process Molding Process Anna ► Flow Circuit Modeling, Flow Tuning Mitul ► Data Acquisition and Control Systems Song ► Harvard Pump Modification, Prototyping Full Team ► Background Research Benchmarking Benchmarking Brainstorming Brainstorming Prototyping Prototyping Testing Testing

2/10/03ME IT’S A GREAT TIME TO BE ALIVE™ Questions?