1
RESEARCH POSTER PRESENTATION DESIGN © 2012 www.PosterPresentations.com Penn State/3M and Minnetronix developed an implantable motor controller and transcutaneous energy transmission system (TETS) for the total artificial heart (TAH) to eliminate the percutaneous cable [1]. Introduction Minnetronix and Evergreen Medical Technologies have worked with Penn State to update the implantable controller, TETS coils, cables, and connectors to improve their construction and implementation of the system. The system is designed to work with the Penn State Tesla left ventricular assist device. Updates include the following: • Smaller, thinner TETS coils for easier implant • Header with embedded connectors and isolation seals • An internal frame for support of components and easier assembly • Implementation of a Medical Device Radio Communication Service (MedRadio) also known as Medical Implant Communications Service (MICS) for data telemetry only • Ability to run the system without a MICS connection as the TETS does NOT require an RF feedback link • Addition of a Li-Ion battery pack to increase run time when decoupled from TETS Objectives • Internal frame for ease of construction • Li-Ion battery pack • Titanium outer enclosure • Poured epoxy header with embedded connectors and isolation seals • Linear inline connectors for pump motor similar to DF4/IS4 standard [3] and pump pressure sensor similar to neurostimulator connections • Pin connectors inspired by early pacemaker connections • MICS antenna embedded in header • 245 cm 3 total volume for the controller • Designed to support chronic animal studies Implant Controller Construction TETS system delivers efficient power transfer over distance and remains cool [2]. • TAH system maximum heat flux was 15 mW/cm 2 • Tesla coils maximum heat flux < 10 mW/cm 2 for distances under 3cm TETS Power Transfer Penn State Tesla Pump Pumping mechanism based on viscous forces imparted by rotating discs to reduce shear-related adverse effects including hemolysis, platelet activation, and acquired von Willebrand syndrome. Includes integrated pressure sensor to detect suction events. Disclosures Lori Lucke, Jack Mondry, Minnetronix Inc., Saint Paul, MN, Steven Scott, Evergreen Medical Technologies Inc., St. Paul, MN, William Weiss, Penn State Hershey Medical Center, Hershey, PA A Totally Implantable Controller For Use With Rotary LVADS The TAH controller used hermetic connectors from the military market and was hand assembled. The system was successfully implanted in 66 chronic animal studies. TETS System and Coils • Subcutaneous coil resized from 29 cm 3 to 10 cm 3 to improve implantation in the infraclavicular region • Primary coil resized from 33 cm 3 to 26 cm 3 to increase usability • Subcutaneous coil designed with integrated connectors to improve implantation connection Performance Specifications TAH TESLA VAD Input supply voltage 12-17 VDC 12-15 VDC Output voltage 16 VDC 18 VDC Power delivered 15-80 W 0-22 W Startup Power 80 W 22 W Operating frequency 200 KHz 790 KHz Primary coil diameter 115 mm 95 mm Secondary coil 95 mm 55 mm Min. coil separation 0 mm 0 mm Max. coil separation 25mm 30mm 10mW/cm^2 20mW/cm^2 30mW/cm^2 10mm 20mm 30mm 40mm 50mm 0.4 0.45 0.5 0.55 0.6 0.65 0.7 0.75 0.8 0.85 0.9 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 Efficiency Output Power (W) TETS system delivers power with no RF feedback link. AC Power Adapters External Controller (PC + TETS development stand) TETS Connection USB Port Primary Coil Secondary Coil Internal Controller Internal External MICS Power Connector Pump Connectors Connectors Battery Antenna Power Medical AC Isolation Transformer Tesla System Diagram LVAD Implant Configuration TAH Implant Animal No coil tissue damage Tesla LVAD Implant Animal TETS System Diagram TETS Efficiency, Output Power, and Heat Flux TAH vs. Tesla LVAD TETS Coils Tesla LVAD TETS Coils Implant Coil with Integrated Connectors Inverter and Coil Interface Microprocessor Vin Control Drive Sense Feedback Sense Coil Interface and Rectifier Regulator Comm Comm Sense/Ctrl Control Sense Comm Vout External TETs External Application Controller Internal Application Controller Internal TETs Implantable Controller External System Implantable Pump Internal Battery Power Switch Battery or External Power Skin Barrier External Coil Internal Coil Tesla LVAD Bench Test System Tesla Implant Controller Exploded View Tesla Controller Front Tesla Controller Back Tesla Controller Header Tesla Motor and Pressure Connectors References [1] A. Snyder, G Rosenberg, J. Reibson, J. Donachy, G. Prophet, J. Arenas, B. Daily S. McGary, O. Kawaguchi, R. Quinn, W. Pierce, “ An Electrically Powered Total Artificial Heart Over 1 Year Survival in the Calf”, ASAIO Journal, July/Sept 1992. [2] V. Bluvshtein, L. Lucke, W. Weiss, “Wireless Power Transmission for Ventricular Assist Devices”, ASAIO Annual Conference, Jun 2013. [3] ISO 27186 Active implantable medical devices -- Four-pole connector system for implantable cardiac rhythm management devices - Dimensional and test requirements, 2010 LVAD Implant Controller TAH Implant Controller TAH Implant System Tesla Pump Cross-Section Tesla Pump Exploded View Results The Tesla system has several improvements over the original TAH system including • Smaller, cool TETS coils • Power transfer suitable for an LVAD • Construction of controller designed for manufacturability and testing • Connectors integrated with cables • Header constructed with embedded connectors • MICS for telemetry • Li-Ion battery Minnetronix SBIR grants with Penn State were used to develop the Tesla system and TETS system • NIH 1 R43 HL108434-02 • NIH 1 R43 HL108415-02
