MSD Project 13022 VAD BREAKAWAY POWER Detailed Design Review 2/8/2013 Joe Tartakoff Customer/Graduate Consultant jat2704@rit.edu Matthew Myers ISE Project Leader mcm8294@rit.edu Nick Dominesey ME Lead Engineer njd3574@rit.edu Jason Inman EE Team Member jpi7658@g.rit.edu Chris Smith ME Team Member cjs5192@g.rit.edu Ellie Sanford egs5491@rit.edu Michael Edson mce5689@rit.edu Matt 2/8/2013

MSD Project 13022: Breakaway VAD Agenda MSD1 Final Review 2/15/2013 Project Overview Customer Needs, Engineering Specs & Testing Plan Chosen Concept Block Diagram and Circuit Diagram* Feasibility Analysis Work Breakdown Structure* System Design Proposal* Bill of Materials* Risk Assessment* Plan for MSD2 Weeks 1-3* Matt *new from Detailed Design Review Presentation MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD MSD1 Final Review 2/15/2013 Project Background 6-10% of all people worldwide over the age of 65 will develop heart failure. There are 287,000 deaths per year due to heart failure in the US. The Thoratec Heartmate II Left Ventricular Assist Device (LVAD) is a bridge-to-transplant device that assists the heart, pumping blood throughout the body for those who are awaiting a heart transplant. Ellie MSD Project 13022: Breakaway VAD

Present LVAD External Power MSD1 Final Review 2/15/2013 Present LVAD External Power Ellie http://www.thoratec.com/ MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD MSD1 Final Review 2/15/2013 Project Summary The transcutaneous power cord that connects the implanted device to the external motor control unit is often a source of infection. The cord is only about 1 foot long so it doesn’t catch on things. When the unit is dropped, the skin around the cord tears and becomes infected. Ellie MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD MSD1 Final Review 2/15/2013 Project Objectives Create a breakaway port for power cable that will detach with a certain amount of force. Cable port is implanted where the cable leaves the body Increase flexibility of cable and reduce stress on surrounding skin Create an internal power supply and motor control unit for the pump when the cord becomes disconnected. Backup power should last long enough for the patient to seek assistance if something goes wrong Ellie MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD Customer Needs MSD1 Final Review 2/15/2013 Matt MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD Engineering Specs MSD1 Final Review 2/15/2013 Matt MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD Needs and Specs MSD1 Final Review 2/15/2013 Matt MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD Chosen Concept MSD1 Final Review 2/15/2013 Jason Note Regarding Heat Control: Battery Recharging will cease if Temperature exceeds limit. MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD MSD1 Final Review 2/15/2013 Block Diagram Legend: Existing Action New Action Existing Device New Device 10 10 Mike 40oC MSD Project 13022: Breakaway VAD

Circuit Wiring Diagram MSD1 Final Review 2/15/2013 MSD Project 13022: Breakaway VAD

Battery Discharge Feasibility Test Results Battery Discharge Time Data Time(Min) Voltage(V) 13.300 4 13.200 6 13.165 7 13.155 8 13.140 10 13.135 31 13.117 50 13.054 86 13.040 151 12.993 168 12.839 194 12.772 196 12.493 203 12.434 209 11.950 MSD Project 13022: Breakaway VAD

Specs vs Subcomponents MSD1 Final Review 2/15/2013 Specs vs Subcomponents Mike MSD Project 13022: Breakaway VAD

Force Pull Test on Skin - Angles MSD1 Final Review 2/15/2013 Force Pull Test on Skin - Angles MSD Project 13022: Breakaway VAD

Force Pull Test on Skin - Results MSD1 Final Review 2/15/2013 Force Pull Test on Skin - Results Angle of Disconnect Force (N) Displacement of skin (mm) Feeling Assessment Comments 90 degrees 1 light   2 5 medium 2.5 10 med-heavy 3 heavy 3.5 12 too heavy 4 15 45 degrees - light-med. reasonable disconnect upper limit 0 degrees very light barely feel it Nick Upper spec of 3 N chosen because it was usually the upper limit for pain tolerance. Lower limit is 1 N because that’s when it started to feel uncomfortable. Angle of 0 degrees was chosen as the ideal angle because applied force tends to induce the least amount of stress on the body at this angle. MSD Project 13022: Breakaway VAD

Heat Analysis - Assumptions MSD1 Final Review 2/15/2013 Heat Analysis - Assumptions Body Temperature (Environment) is 37˚C Heat distribution on outside of device will be modeled via FEA Heat transfer method inside body is conduction All energy inefficiencies result in heat generation Device is surrounded my muscle tissue which is at equilibrium between perfusion and heat generation MSD Project 13022: Breakaway VAD

Heat Analysis – Additional 1D Assumptions MSD1 Final Review 2/15/2013 Heat Analysis – Additional 1D Assumptions 1 dimension normal to the skin Uniform heat generation Constant Properties Body is at equilibrium (neglect heat generation effects) Steady State MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD MSD1 Final Review 2/15/2013 Heat Analysis - Data Reference Temperatures[C]: Body Temp= 37 C Ambient Air Temp= 25 C Conduction Coefficients : Internal Organs and Muscle = 0.500 W/m*K Skin and Fat=0.300 W/m*K Titanium=19.000 W/m*K (P13022 only) Clothing=0.029 W/m*K Convection Coefficients [W/m*K]: Air=10.000 MSD Project 13022: Breakaway VAD

Heat Analysis – Critical Values MSD1 Final Review 2/15/2013 Heat Analysis – Critical Values The purpose of our thermal model is to ensure this device will not harm the patient. With a factor of safety of 2, our maximum heat flux through the tissue is 40mW/cm2 MSD Project 13022: Breakaway VAD

Heat Analysis – 1D Analysis Model MSD1 Final Review 2/15/2013 Heat Analysis – 1D Analysis Model MSD Project 13022: Breakaway VAD

Heat Analysis - Results MSD1 Final Review 2/15/2013 Heat Analysis - Results MSD Project 13022: Breakaway VAD

Heat Analysis – Engineering Model MSD1 Final Review 2/15/2013 Heat Analysis – Engineering Model Boundary Temp: 37˚C Conduction Device Internal Environment (Abdomen Muscle) The Device will be implanted in abdomen muscle Assuming a worst case scenario, the device will be surrounded by muscle tissue in all directions for an “infinite” thickness. An ANSYS model which includes the boundary temperature of 37˚C and all muscle properties will show worst case temperature and flux conditions MSD Project 13022: Breakaway VAD

Heat Analysis - Summary MSD1 Final Review 2/15/2013 Heat Analysis - Summary For the given area of 64cm2 , 0.3 W (4.67mW/cm2) of heat generation will be dissipated before exceeding 40oC. For a surface area of 340cm2 we should be allowed to generate up to 13.6 W of heat energy within the device. Expected worst case heat generation = 2 W. MSD Project 13022: Breakaway VAD

Heat Analysis - Conclusion MSD1 Final Review 2/15/2013 Heat Analysis - Conclusion The Internal Battery Storage Device is not likely to harm the body through heat generation based upon the of energy flux through the total surface area. Further analysis will be conducted (in ANSYS) to confirm the results. Due to the extreme difficulty of finding a relatively accurate model for the body in relation to the LVAD system, the 1-D analysis is only useful for worst case results and only provide limited useful data. Further analysis in ANSYS should provide more reliable results. Development of the P13022 device should continue with minimal design change. MSD Project 13022: Breakaway VAD

Antenna Radiation Analysis MSD1 Final Review 2/15/2013 Antenna Radiation Analysis Antenna Radiation-Heat Energy Analysis Given: Radiation Energy, q = 10mW Maximum Heat Flux, q” = 40 mW/cm^2 Length of wire = 25cm Find: Diameter of wire to account for surface area needed to dissipate energy. 𝑟= 𝑞 2𝜋ℎ𝑞" = 10𝑚𝑊 2∗𝜋∗25𝑐𝑚∗40𝑚𝑊/ 𝑐𝑚 2 =0.0016𝑐𝑚 𝐷=0.0032𝑐𝑚=0.032𝑚𝑚 Result: Diameter must be at least 0.032mm. MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD Wire Gauge Analysis Based on the shielded wire that we plan on ordering from awcwire.com and its thickness, it will allow us to use 20 AWG wire without exceeding our heat flux limit. MSD Project 13022: Breakaway VAD

Work Breakdown Structure - Chart MSD1 Final Review 2/15/2013 MSD Project 13022: Breakaway VAD

Work Breakdown Structure - Diagram MSD1 Final Review 2/15/2013 Work Breakdown Structure - Diagram *On Edge currently MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD MSD1 Final Review 2/15/2013 System Model Mike MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD MSD1 Final Review 2/15/2013 System Model (sketch) Existing Batteries Internal Pump (Thoratec Heartmate 2) Internal Signal Controller & Batteries Breakaway Port Mike External Signal Controller External Pump Monitor MSD Project 13022: Breakaway VAD

Internal Power Control Case Configurations MSD1 Final Review 2/15/2013 Internal Power Control Case Configurations Mike MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD MSD1 Final Review 2/15/2013 Port Design Options Angled Port Cup Port Straight Port Flat Port MSD Project 13022: Breakaway VAD

Breakaway Port Selection MSD1 Final Review 2/15/2013 Breakaway Port Selection Port Design Measures of Evaluation Straight Cup Angled Flat Functionality 2 4 3 1 User Friendly Ease of Production Stress on Body Cost Value Total Score 11 12 14 Definitions: Functionality The cable will remain connected under most circumstances. User Friendly Relates to how likely the cable is to catch on objects and is dependent on the angle of the wire coming out of the port. Ease of Production Relates to how easy it will be for us to manufacture the port. Stress on Body Relates to the amount of stress that is expected to occur due to snags or brushing the port and is dependent on the amount of material on the female port that is protruding from the body. Cost Value Antipated cost after purcasing and manufacture and includes amount of time we would have to spend making the part. MSD Project 13022: Breakaway VAD

Breakaway Port Design Selection MSD1 Final Review 2/15/2013 Breakaway Port Design Selection Mike MSD Project 13022: Breakaway VAD

Expert Recommendations MSD1 Final Review 2/15/2013 Expert Recommendations MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD MSD1 Final Review 2/15/2013 Bill of Materials MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD MSD1 Final Review 2/15/2013 Risk Assessment MSD Project 13022: Breakaway VAD

Vision for MSD2 Weeks 3 Demo. MSD1 Final Review 2/15/2013 Vision for MSD2 Weeks 3 Demo. Shared Vision for Week 3 The goal is to have all functional properties separated into their respective working models. Plastic Prototype of Port with Magnets Minimize the size in an effort to save every last millimeter of space and reduce overall size of plug and jack. Design smooth form prototypes if possible. Internal Device Housing Prototype. Plastic mockup to spec. For large batteries and/or AA battery size. Electrical Function Prototype. Battery charging circuit. Pump controlling circuit. MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD Plan for MSD2 Weeks 1-3 Three (3) Week Plan in Order to Reach our Shared Vision of the Week 3 Demonstration: Week 1: Create 3 detailed drawings with exact specs of all port part parameters so that the port alpha prototype designs are ready for machining. 3 drawings may include: Our 1st choice of design. Dr. Duncan’s recommended design. Surgeon’s recommended design or our 2nd choice of design. Conceive and document all possible trade-offs associated with each design. Capture and summarize. Produce a nice little table. Confirm Schedule of week 2 meeting with all involved parties (Dr. Day, Dr. Duncan, Surgeon, Joe, Mr. Hanzlik, team, etc.) Create detailed drawing of internal housing, including battery holders if necessary. Complete geriatric research. Determine influence on design. Give the go-ahead to produce prototypes. MSD Project 13022: Breakaway VAD

MSD Project 13022: Breakaway VAD Plan for MSD2 Weeks 1-3 Week 2: Rapid Prototype the 3 port designs by Thursday. Hold meeting with all involved parties (Dr. Day, Dr. Duncan, Surgeon, Joe, Mr. Hanzlik, team, etc.) Get feedback about designs. They should be able to make a proper assessment with scaled 3D physical models at their disposal. Walk out with a winner and final design. Rapid Prototype the Internal Housing. Week 3: Demonstrate all sub-level functions (as described above in the Shared Vision) Breakaway Port Plastic Prototype. Internal Housing. Electric Components. MSD Project 13022: Breakaway VAD

System Model (sketch) I love my new breakaway port system! MSD1 Final Review 2/15/2013 System Model (sketch) I love my new breakaway port system! Hanzlik in 20 years. Mike MSD Project 13022: Breakaway VAD