Project Number: GRG-1601 A Papillary Muscle Repositioning Device for the Elimination of Mitral Regurgitation A Major Qualifying Project Report submitted to the faculty of WORCESTER POLYTECHNIC INSTITUTE In Partial Fulfillment of the Requirements for the degree of Bachelor of Science Date Submitted: April 27, 2016 Submitted by: Nadjia Edwards: __________________________ Keith Guay: ______________________________ Danielle Healy:___________________________ Approved: Professor Glenn Gaudette, Ph.D:____________________________ Professor John Sullivan, Ph.D:______________________________ Table of Contents Table of Contents ...........................................................................................................................................2 Acknowledgements ........................................................................................................................................5 Abstract ..........................................................................................................................................................6 List of Figures .............................................................................................. Error! Bookmark not defined. List of Tables .................................................................................................................................................8 I. Introduction ............................................................................................................................................9 II. Literature Review .............................................................................................................................11 Physiology of Mitral Valve and Papillary Muscles .................................................................................11 Papillary Muscle Rupture ........................................................................................................................15 Papillary Muscle Repair ...........................................................................................................................15 Mitral Valve Repair .................................................................................................................................16 Fibrin Mircothreads and Regeneration ....................................................................................................16 Stem Cells as a Means of Regeneration ...................................................................................................17 Cell Integration in Scaffolds ....................................................................................................................18 Cell Integration in Hydrogels ...................................................................................................................19 Ischemic Left Ventricular Distortion .......................................................................................................21 Polymer Integration .................................................................................................................................23 Nitinol ......................................................................................................................................................27 III. Project Strategy ................................................................................................................................27 Initial Client Statement ............................................................................................................................27 Revised Client Statement .........................................................................................................................28 Functions and Objectives .........................................................................................................................28 Project Approach .....................................................................................................................................31 IV. Design Process .................................................................................................................................31 Needs Analysis .........................................................................................................................................31 Length of Papillary Muscle: .................................................................................................................32 Displacement of Papillary Muscle after Myocardial Infarction: .........................................................33 Geometric Orientation during Systolic and Diastolic Cardiac Cycles: ...............................................33 Strain on Papillary Muscles during Cardiac Cycle: .............................................................................33 Maximum Forces on Papillary Muscle: ...............................................................................................34 Angular Displacement of Papillary Muscle after Myocardial Infarction: ...........................................34 Pressures of Diastole and Systole: .......................................................................................................34 Pressure of Diastolic and Systolic after Myocardial Infarction: ..........................................................35 Design Requirements and Functions .......................................................................................................35 Functions ..................................................................................................................................................36 Specifications ...........................................................................................................................................36 Important Industry Standards ...................................................................................................................37 Conceptual Designs .................................................................................................................................37 Design 1: Webbed Polymer Coating ........................................................................................................38 Design 2: Surface Modification for Chordae Attachment .......................................................................39 Design 3: “Silly Putty” Attachment .........................................................................................................39 Design 4: Attachment of Cardiac Cells to Surface ..................................................................................40 Design 5: “Suction Cup” Method ............................................................................................................41 Design 6: Full Replacement with Polymer ..............................................................................................42 Design 7: Insertion of Polymer Loop .......................................................................................................43 Design 8: Papillary Anchor ......................................................................................................................43 Design 9: Velcro Design ..........................................................................................................................44 Design 10: Conducting Polymer Addition ...............................................................................................45 Design 11: Grow a New Papillary Muscle ..............................................................................................45 Design 12: Collagen Cross-linked Hydrogel with Cardiac Cells ............................................................46 Design 13: Annuloplasty Ring Idea .........................................................................................................47 Design 14: Retractable Suture Method ....................................................................................................47 Design 15: Nitinol Cantilever Design ......................................................................................................48 Design 16: PTFE String through Heart ....................................................................................................49 Alternative Designs ..................................................................................................................................50 Design 1: Webbed Polymer Coating ....................................................................................................51 Design 2: Surface Modification for Chordae Attachment ...................................................................51 Design 3: “Silly Putty” Attachment .....................................................................................................51 Design 4: Attachment of Cardiac Cells to Surface ..............................................................................52 Design 5: “Suction Cup” Method ........................................................................................................52 Design 6: Full Replacement with Polymer ..........................................................................................52 Design 7: Insertion of Polymer Loop ...................................................................................................53 Design 8: Papillary Anchor ..................................................................................................................53