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

Department of Biomedical Engineering, Institute of Technology

ABSTRACTThe Ablatech Tumor Ablation Delivery System (TADSystem) is a device that uses Direct Current (DC) Ablation (or electrochemical therapy) to induce 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 epoxy. The needle is insulated using polyolefin heat shrink 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.

   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.

Anode: H20 - 2e- ½ O2(g) + 2H+

Cathode: H20 +e- ½ H2 + OH-

MATERIALS & METHODS

SURGERY CRYOABLATION DC ABLATION

Scarring Large Size Small Size

Poor Reimbursement

Poor Ergonomics Minimal Scarring

Vasculature Issues Better Ergonomics

High Cost Ease of Use

Low Cost

Lipoma

E.B.A.

D.C.

A. Stainless steel needle milled to halfB. Steel halves coated epoxy insulationC. Two needle halves glued together using epoxy resinD. Tip machined and needle insulated revealing electrodesE. Needle with handle attached

Confirm/Cancel

Prompt for Tissue Selection

Fibroadenoma SelectedLipoma Selected

Display Treatment Time and Prompt To Start

Confirm/Cancel

Prompt for Volume Input

Initialize and Start Treatment

CancelledCancelled

GENERATORTREATMENT ALGORITHM

PROTOTYPE TESTING

CONCLUSIONS•Many of the structural requirements for the delivery device were proven with insertion testing and buckling testing and the treatment was proven to be 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.

FUTURE IMPROVMENTS•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

“KILL ZONE”Lipoma-Control Porcine

Fibroadenoma-Control Porcine

Lipoma-Experimental Porcine

“Kill-Zone”

Fibroadenoma-Experimental Porcine

“Kill-Zone”

DELIVERY DEVICE

Treatment Circuit Schematic

Generator Logic

NEEDLE BUCKLING TEST

INSERTION FORCE

•Insertion force testing was a necessary component in ensuring patient safety. The 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.

Market Competition

•A controlled and predictable lesion radius was observed in tissue testing•Diffusion patterns were well-defined and predictable for multiple tissue types

ACKNOWLEDGEMENTS•Advisors: Kai Kroll and Tom Nelson, Oncostim Inc.•Dillon and Stephan, MDC•Dr. Steven Saliterman

•Rob Yucha •Dr. William Durfee•Peter Zimmerman