NATE CHAMBERLAIN, DAVE GOLDMAN, PHIL MATTA, HUY NGUYEN, KWAKU OPOKU, MEGAN PETERSON

1. D.C. ABLATION OF BENIGN TUMORS Lipoma-Experimental Porcine Lipoma-Control Porcine “Kill-Zone” NATE CHAMBERLAIN, DAVE GOLDMAN, PHIL MATTA, HUY NGUYEN, KWAKU OPOKU, MEGAN PETERSON Department of Biomedical Engineering, Institute of Technology ABSTRACT The Ablatech Tumor Ablation Delivery System (TADSystem) is a device that uses Direct Current (DC) Ablation (or electrochemical therapy) to cause tissue necrosis of fibroadenomas and lipomas. DC Ablation technology employs the basic principles of electrolysis which causes the creation of hydrogen ions and hydroxyl ions at an anode and cathode. The TADSystem consists of a delivery device made out of two steel halves insulated from each other using cyanoacrylate . The needle is insulated using polyolefin shrink wrap material leaving bare regions which act as electrodes. The needle is connected to a treatment generator. A dosing algorithm coded into the generator logic circuit determines the charge required to destroy the volume of tissue entered by the physician. The resulting algorithm provides equal treatment times for tumors of the same volume regardless of their type. • MATERIALS & METHODS Fibroadenoma-Experimental Porcine Fibroadenoma-Control Porcine TREATMENT ALGORITHM “Kill-Zone” DELIVERY DEVICE E. D. C. B. A. Stainless steel needle milled to half Steel halves coated epoxy insulation Two needle halves glued together using epoxy resin Tip machined and needle insulated revealing electrodes Needle with handle attached “KILL ZONE” • Clinical Need • FIBROADENOMA • Fibroadenomas are the most common benign breast tumors & are made of glandular and fibrous tissue. • Fibroadenomas range in size from 1cm to 5cm. • There are 700,000 tumors annually. • LIPOMA • Lipomas are benign tumors found underneath the skin or in the muscle. • Can occur anywhere on the body but most common on the torso, neck, upper thighs, upper arms and armpits. • Lipomas range in size from 1 cm to 3 cm. • There are 3 million lipoma tumors annually. • What Is DC ABLATION? • Electrolysis of water. • Generates H+ ions at the anode & OH- ions at the cathode. • Tumor cells die from pH extremes. • Dead cells are removed by body’s defense system. GENERATOR Generator Logic • A controlled and predictable lesion radius was observed in tissue testing • Diffusion patterns were well-defined and predictable for multiple tissue types Prompt for Tissue Selection CONCLUSIONS Cancelled Treatment Circuit Schematic Cancelled NEEDLE BUCKLING TEST • Many of the structural requirements for the delivery device were proved with insertion testing and buckling testing and the treatment was proved both effective and predictable for treating various sample tissue types. Although the aim for this device was to treat tumors ranging in size from 1-4 centimeters, the treatment will only be effective for treating tumors smaller than 3 centimeters in diameter. Lipoma Selected Fibroadenoma Selected Confirm/Cancel Prompt for Volume Input Lipoma Anode: H20 - 2e- ½ O2(g) + 2H+ Cathode: H20 +e- ½ H2 + OH- FUTURE IMPROVMENTS Confirm/Cancel • Reduce needle diameter to further reduce potential scarring • Use platinum coating on the anode to prevent corrosion • Perform tissue testing in actual Lipoma or Fibroadenoma tumor both in vitro and in vivo • Controlled polymer deposition in place of heat shrink insulation Display Treatment Time and Prompt To Start Initialize and Start Treatment ACKNOWLEDGEMENTS • Advisors: • Kai Kroll and Tom Nelson, Oncostim Inc. • Dillon and Stephan, MDC • Dr. Steven Saliterman PROTOTYPE TESTING Market Competition INSERTION FORCE • Insertion force testing was necessary component in ensuring patient safety. Thee force required for insertion must be lower than the critical buckling strength of our needle. These coupled tests proved the design was structurally safe for the insertion forces experienced during the procedure. • Rob Yucha • Dr. William Durfee • Peter Zimmerman