Jon KleinISEProject Manager Nguyen VuMETechnical Lead Kyle MengesMETechnical Lead Christine LowryMEDesign Engineer Chris SteinMEDesign Engineer Priya NarasimhanEEElectrical Engineer Julie CoggshallISESystems Engineer

Customer Needs Top 10 Specifications Blood Sub-System Physiological Sub-System LVAD Test Loop System Architecture Risks and Mitigation Design Reviews Summary Budget Current State of Design Senior Design II Schedule

Design and build a test loop to help in LVAD development by characterizing the pressures and flows associated with the device as well as its impact on blood. 1.Generate pressure and flow curves for static system (automatically adjusted) 2.Extracting fluids while running to determine damage to blood 3.Process data to generate pressure and flow curve for dynamic system (scaled model of the physiological circulatory system working with a PVS)

Engr Spec #MetricUnitsIdeal Value Lower Limit Upper Limit ES1System Leakage# leak locations002 ES6Portabilityminutes45160 ES9CostU.S. Dollars ES13Pressuremm Hg ES14Pressure Accuracymm Hg ES15Flow Rateliters/minute6010 ES16Flow Rate Accuracyliters/minute ES17Temperaturedegrees C (F)37 (98.6)21 (70)49 (120) ES18Temperature Accuracydegrees F ES22System LxWxHinches48x36x3036x12x1260x48x36

Principle Schema B-Automated resistance A-LVAD D- Temperature controlled bath C-Reservoir /Blood extraction D C A B Differential pressure sensor Flow sensor

Blood reservoir/ Water bath B A C Heating Element (A) Blood reservoir: fill the system, air removal, blood extraction (B) Circulation Pump (C) Water bath: maintain the temperature of the blood (D) D

Glycerin mix (A) Arterial Compliance tank (B) Pressure regulator (C) Resistance (D) PVS (E) LVAD (F) A B C D E F

Valved quick-connect Drainage Points

DAQ Mechanical System Test loop with LVAD and PVS Mechanical System Test loop with LVAD and PVS Stepper motor Pressure sensor Flow sensor Thermocouple Computer: Labview used to monitor temperature and plot flow and pressure curves Pressure of liquid Flow rate of liquid Temperature of liquid Variable resistance

Risk AreaRisk ItemDescription/CommentMitigation Activity Measurement Inaccurate measurements Pressure and flow measurements are inaccurate Use proper instrumentation and verify proper placement. Discuss with experts prior to purchasing. DAQ Error Instrumentation and DAQ not communicating properly, DAQ does not collect or output data properly Debug software, document procedure for DAQ operation and troubleshooting. Discuss with experts prior to purchasing.

Risk AreaRisk ItemDescription/CommentMitigation Activity Physiological Simulation Compliance Tank Desired compliance value not achieved Early milestone in test plan to ensure enough time to fix the problem Temperature System temperature is not maintained Monitor fluid and VAD temperature, implement temperature control system Viscosity Viscosity variation does not simulate human blood properties Research and verify the proper mixture of water/glycerin is used, control/maintain temperature

Risk AreaRisk ItemDescription/CommentMitigation Activity Design Leaks System or components leak causing error in measurement and/or contamination Early milestone in test plan to ensure enough time to fix the problem Air bubbles Air bubbles cannot be removed from system – tank sizes do not allow for bubbles to escape, or there are low points in the system Early milestone in test plan to ensure enough time to fix the problem. Use alternative fill method to reduce bubble formation Blood Damage Valves, sensors, connectors damage blood Early milestone in test plan to ensure enough time to fix the problem. Put in separate, simplified loop Resistance Flow restriction does not function properly Design for the implementation of a back-up, manually controlled resistance method

Risk AreaRisk ItemDescription/CommentMitigation Activity Cost Pressure Sensors Desired sensor accuracy not within budget Find suitable DAQ to achieve accuracy DAQ Dedicated DAQ system not within budget Investigate costs, potential for sharing existing DAQ system

DR1  Compliance: Developed electrical equivalent model  Sensors: Use existing flow sensors  System Architecture: Modular, quick-connect design DR2  Simplify Design: Reduce system to a single tank that functions as both a compliance tank and reservoir Use a pressure-cuff to pressurize compliance chamber in place of expensive gauge and regulator  Need to establish more refined electrical specifications

ComponentDescriptionTotal Price General Components Tubing, Connectors, Fittings, Tank, Cart $ Measurement & Data Collection Sensors (Pressure, Thermocouples, Ultrasonic Flowmeter), DAQ $1, Blood Loop Components Water Bath, Heating Element, Pump, Tank Fittings $ Physiological Loop Components Pressure Cuff & Gauge, Fittings (for Tank) $32.27 Automated Resistance Linear Actuator & Stepper Motor, Stand $97.73 Testing Supplies Glycerin, De-Ionized Water, Saline $ TOTAL$3,170.28

Design meets all customer needs Design exceeds upper budget limit by ~ 6% Data collection and control specifications are not finalized Schedule: 1 week behind on electronic component selection Mitigations: Elimination of venous compliance tank → pending approval Budget: Need approval or reduction in specification limits Finalize design by end of week 11 to order parts

Date(Week)Mechanical SystemData Collection and Control Mar 13(Week 1)Closure of MSD I A.I.’s, All Parts from BOM Ordered Mar 20 (Week 2)All Parts Received Apr 3 (Week 4)Loop Components AssembledConnection with PVS and LVAD established Apr 5 (Week5)Final Test Plan complete Apr 24 (Week 6)Compliance ConfirmedConnection with Sensors established May 3 (Week 8)Final Device BuiltLab View Program debugged May 8 (Week 9)Testing Complete & Documented, Poster Complete May 15 (Week 10)Field Demo, Technical Paper, User Manual May 18 (Week 11)Final Documentation

Heating Element Blood Extraction Resistance Female - Valved Male - Valved Female Male Fluid Fill LVAD PVS