Team 12026

PERSONS INVOLVEDROLES  Michael Carozzoni (ME)  Paul Slagle (ME)  Nooreldin Amer (EE)  Naveen George (EE)  Devin Prescott (ME)  William Chan (ME)  Edward Hanzlik  Neal Eckhaus  Dr. Steven Day, PhD  Project Manager  Transmission System Design  Generator Regulator Circuit  Motor Supply Circuit  Receiving System Design  Electromechanical Analysis  Guide  Customer

To research and develop a module for transcutaneous (through the skin) power transmission. The 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 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." CN39Safely 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 CN73ComfortableMinimize compressive pressure on tissue Importance: Sample scale (9=must have, 3=nice to have, 1=preference only).

Eng. Spec. #Importance (1,3,9)SourceLocationFunctionSpecification (metric)Unit of Measure Ideal Value S19CN1InsideOutput PowerPowerW30 S29CN1InsideVoltage OutputVoltageV12~15 S39CN2InsideReliable% reliability%99 S49CN2InsideDesign LiveTimeyears10 S59CN3Inside Minimal heat generation heat generationmW/cm^2<40 S63CN4BothLightweightMasskg<0.45 S73CN5BothSmallDiametercm<7.94 S83CN5InsideThinthicknesscm<3.05 S93CN7BothContact PressureAxial pressure on skinkPa<3.5 S103CN6InsideSealedLeakage ratemL/day0 S113CN6Both Electrically Insulated Leakage currentA0 S129CN1OutsideOutput PowerPowerW39 S139CN2OutsideReliability% Reliable%99 S149CN2OutsideDesign LifeTimeYears1 S159CN7OutsideTemperatureTempdeg C<41 S169CN3Outside Heat Generation at skin surface Heat GenerationmW/cm^2<40 S173CN4OutsideThinThicknesscm<5.08

 Passive magnetic coupling.  Inductive system.  Electromagnetic system. Chose passive magnetic coupling for its simplicity and efficiency. Generator was EC-45 Flat. Chosen for space requirements and to meet specifications. Motor was brushless DC EC-i40. Chosen to meet specifications.

 Input Circuit consists of pulse wave generator, motor controller.  Motor is Brushless DC EC-i40.  Armature and Receiver are six magnets aligned on a disk with NSN aligned polarity.  Generator is EC-45 Flat.  Output Circuit consists of the rectifier circuit.

DESIGN SUMMARY

 Dimensions and masses meet planned specifications, with the exception of implant diameter.  Contact pressure met specification even when the two faces met.  Implant case was fully ingress protected, and fully electrically insulated (before damage).  Voltage and output power did not meet specifications, due to the absence of a functional voltage regulator.  Reliability could not be calculated.  Design life passed for the motor, but failed for the generator. Both were found to be 6 years.  Outside temperature of the case surface was unable to be found.

Eng. Spec. # Importance (1,3,9) SourceLocationFunctionSpecification (metric)Unit of Measure Ideal Value Actual Value S19CN1InsideOutput PowerPowerW3016 S29CN1InsideVoltage OutputVoltageV12~1580 S39CN2InsideReliable% reliability%99N/A S49CN2InsideDesign LiveTimeyears106 S59CN3Inside Minimal heat generation heat generationmW/cm^2<4076 S63CN4BothLightweightMasskg< S73CN5BothSmallDiametercm< S83CN5InsideThinthicknesscm< S93CN7BothContact PressureAxial pressure on skinkPa< S103CN6InsideSealedLeakage ratemL/day00 S113CN6Both Electrically Insulated Leakage currentA00 S129CN1OutsideOutput PowerPowerW3932 S139CN2OutsideReliability% Reliable%99N/A S149CN2OutsideDesign LifeTimeYears16 S159CN7OutsideTemperatureTempdeg C<41 ??? S169CN3Outside Heat Generation at skin surface Heat GenerationmW/cm^2< S173CN4OutsideThinThicknesscm<

VendorAmount DigiKey $ McMaster-Carr $ Maxon $ Express PCB $ Other $ Surplus $ 36.64

 Feedback circuit to identify when the system is out of alignment  Smaller Casing  Greater Power Transfer  Higher efficiency  High efficiency motor-generator set.  High efficiency circuitry  Frameless motor for generator side