P12026: Transcutaneous Power Transmission Team Members Nooreldin Amer Michael Carozzoni William Chan Naveen George Devin Prescott Paul Slagle

Outline  Project Description  Review of Needs, Specifications  Functional Decomposition  Basic Calculations and Simulations  Concept design  Component selection  Review of Risks  Work Breakdown Structure  Schedule for MSD I

Project Description  T eam is currently researching and developing a module for transcutaneous (through the skin) power transmission. Our project involves the transmission of power through a gap using passive magnetic coupling. This unit has potential as a medical device, and is intended as a proof-of-concept for future application in ventricular assist devices (VAD).

Customer Needs Customer Need # ImportanceDescriptionComments/Status CN19 Transmit power wirelessly "Functional prototype paired motor and generator set with passive magnetic coupling." "Delivered system must be “sized” to be able to yield 100 watts at the motor (receiver)." CN29 Lasts long and is reliable "Estimated design life of 99% reliability at 10+ years with 95% confidence." CN3 9Safely implantableBio-compatible and low heat generation CN43Light "System weight less than 1 pound." CN53Small "Inner and outer components of the system must each be the size of a hockey puck or smaller." CN63Contained Shell containing device to prevent unwanted mass or energy transfer CN7 3Comfortable Minimize compressive pressure on tissue Importance: Sample scale (9=must have, 3=nice to have, 1=preference only).

Engineering Specifications Spec. #ImportanceSourceFunction Specification (metric) Unit of Measure Ideal Value Comments/ Status S19CN1Output PowerPowerW100 S29CN1Voltage OutputVoltageV12~15 S39CN2Reliable% reliability%99 S49CN2Design LifeTimeYears10 95% confident S59CN3 Minimal Heat GenerationHeat generationmW/cm²<40 S63CN4LightweightMasskg<0.45 S73CN5SmallDiametercm<7.6 S83CN5ThinThicknesscm<2.54 S93CN7 Contact Pressure Axial pressure on skinPaTBD S103CN6SealedLeakage ratemL/day0 S113CN6 Electrically InsulatedLeakage currentA0 Importance: Sample scale (9=must have, 3=nice to have, 1=preference only).

House of Quality Engineering Metrics Customer Requirements Customer Weight Output Power Voltage Output Reliable Design Life Minimize Heat Generations Lightweight Small Thin Contact Pressure Sealed Electrically Insulated Transmit Power Wirelessly Lasts long and is reliable Safely Implantable Light Small Contained 3 99 Comfortable 3 9 Target Values 100W Power Output 12-15V Output 99% Reliable for 10 years Last 10 years 95% confident heat loss <40 mW/cm^2 Mass <0.45kg <7.6cm Diameter <2.54 cm thick Axial Pressure TBD Pa leak 0mL/day leaked 0 A/day RawScore Relative Weight12%9%12% 15%4%7% 3%9% Rank

Functional Decomposition

Basic Calculations and Simulations

Basic Calculations and Simulations (continued)

Concept Selection  Concept A: Perpendicular Passive Magnets  Concept B: V-Oriented Passive Magnets  Concept C: Parallel-Slanted Passive Magnets  Concept D: Electromagnet Stepper Concept B Concept A

Concept Selection Concept C Concept D

Concept Selection Selection Criteria Concept A (Baseline) Concept BConcept CConcept D Material Cost000- Build Time0--- Ease of Fabrication0--- Testing Variability000- Maintenance and Calibration 000- Controllability000+ Expected Output0+++ Total Score0 -3 Rank1224 Concept A: Perpendicular Passive Magnets Concept B: V-Oriented Passive Magnets Concept C: Parallel-Slanted Passive Magnets Concept D: Electromagnet Stepper

Current Technology

Motor/Generator Selection Nomenclature Speed (RPM) Price ($) Thickness (mm) Diameter (mm) Volume (mm^3)AC/DC No. Phases Max Power (W) Power Density (MW/m^2) Brush- less Efficiency (%) Mass (g)Comments Spec E >96%453 Maxon EC 45 Flat10, E+04DC yes83.2~ EC 2260, E+04DC yes89.7~ $30 for Hall Effect sensor EC Max 4012, E+05DC yes81.7~ Faulhaber Series 3257 … CR5, E+04DC no83242 Series 3272 … CR5, E+04DC no88312 PMW GPM123, E+06DC no-- ebmpapst VD B004, E+05DC yes-590See Link 1 VD B026, E+05DC yes-520See Link 2 VDC D004, E+05DC yes-590See Link 3 Portescap 32BF 3C K.0312, E+03DC310-yes-26See Link 4 ApplimotionUTH Series E+04AC Yes 136 NotesDesign Envelope Spec diameter is 90% of envelope diameter Thickness (mm)Diameter (mm) Volume (mm^3)Area (m^2)Total Heat Generation (W)Mass (g) Spec thickness is 75% of envelope thickness Spec efficiency comes from 40mW/cm^2 heat generation (6W total loss) E Spec mass comes from 80% total system weight Link 1http:// Link 2http:// Link 3http:// Link 4http://

Motor/Generator Selection MaxonFaulhaberPMWebmpapstPortescapApplimotion Criteria Ideal Motor* EC 45 Flat EC 22 EC Max 40 Series 3257 CR Series 3273 CR GPM 12 VD B00 VD B02 VD D00 32BF 3C K.03UTH Series Efficiencyx-----xxxxxx Max Powerx Volumex Massx Costx++-xxxxxxx- Sum +'sx Sum 0'sx Sum -'sx Sum x'sx Net Scorex Uncertaintyx Rankx *Efficiency 96% *Max Power 105W *Volume mm^3 *Mass 0.25 kg *Cost $250

Review of Risks IDRisk ItemEffectCause Likelihood Severity Importance Action to Minimize RiskOwner Describe the risk briefly What is the effect on any or all of the project deliverables if the cause actually happens? What are the possible cause(s) of this risk? L*S What action(s) will you take (and by when) to prevent, reduce the impact of, or transfer the risk of this occurring? Who is responsible for following through on mitigation? 1 High Heat GenerationNot meeting specifications, Low generator efficiency, improper heat dissipation,339 Research into generators, dissipating heat properlyDP 2 High Operating RPM failureUnsafe testing conditionPower requirements236 Extra layer of safety during testing, gearingDP 3 Breakdown Torque/SlippageLose transmission of power Large air gap, weak magnet strength,236 Ramp-up algorithm, fail-safe mechanismWC 4 Low Power Transmission Not meeting power transmission requirement Heat specification causing a bottleneck326 Research into generators, proper heat dissipationMC 5 Low Motor Efficiency Possible too much heat generation, not meeting other specifications Lack of research into motors,224Do research regarding motor,NG 6Large deviceNot meeting specification, Trying to meet specification, not enough research224 Research components, negotiate with customer,PS 7 Failure of parts due to TransienceHigher stressGoing from 0 to x RPM,112 Ramp-up algorithm, factor of safetyNA Likelihood scaleSeverity scale 1 - This cause is unlikely to happen1 - The impact on the project is very minor. We will still meet deliverables on time and within budget, but it will cause extra work 2 - This cause could conceivably happen 2 - The impact on the project is noticeable. We will deliver reduced functionality, go over budget, or fail to meet some of our Engineering Specifications. 3 - This cause is very likely to happen3 - The impact on the project is severe. We will not be able to deliver, or what we deliver will not meet the customer's needs.

Interface with Sub-assemblies Responsibilities Design TeamTest Team Power Supply Will have an external and internal power supplies Motor/Generator Assembly Will have a thermistor circuit in the motor/generator assembly to measure heat Will collect the data from the thermistor using the respective software Torque Measurement Will take responsibility RPM Measurement Will have a slit in the casing for accessing the motor for measurement Will use an optical sensor to measure the RPM of the motor Contact Pressure on Skin Will measure the pressure by using a type of pressure film or force gauge Rectifier circuit (if needed) Will provide access points Will measure the current, voltage of desired components on the circuit. Loads for Measurement Will provide a range of loads for the product to see the functioning of the total product

Work Breakdown Structure

Work Breakdown Structure (continued)

Schedule for MSD I