Dustin Borg, ME Patrick Henley, BME Ali Husain, BME Nick Stroeher, BME Advisor: Dr. Joel Barnett

What is Plasma? Plasma is a state of matter with enough free charged particles so that its dynamics are heavily influenced by electromagnetic forces.  gaseous fluid-like mixture of ions, free electrons,radicals and excited atoms and molecules The Plasma Needle uses Low-Temperature Plasma (LTP)  small fraction of neutral particles in gas are ionized  electrons are high energy; ions are ambient temp.  retains neutral charge

Problem Plaque can build up in blood vessels leading to infarctions, stoppage in blood flow or possibly to heart attack Plaque can build up in blood vessels leading to infarctions, stoppage in blood flow or possibly to heart attack Subjects [with] cholesterol, were about two-and-a-half times more likely to have advanced plaque blockages in their coronary arteries Subjects [with] cholesterol, were about two-and-a-half times more likely to have advanced plaque blockages in their coronary arteries Heart disease is America's major killer Heart disease is America's major killer Severe blockage due to arterial plaque, a clot, a spasm, or any combination of these, may lead to a myocardial infarction, the dreaded heart attack, resulting in cardiac dysfunction and often rapid death Severe blockage due to arterial plaque, a clot, a spasm, or any combination of these, may lead to a myocardial infarction, the dreaded heart attack, resulting in cardiac dysfunction and often rapid death

Possible Solution? Cholesterol builds underneath the endothelium tissue at early stages of arterial blockage Cholesterol builds underneath the endothelium tissue at early stages of arterial blockage Slowing – or possibly eliminating – the buildup of cholesterol beneath endothelium tissue can hypothetical lower the risk of arterial blockage

Current Known Effects of Plasma on Cell Tissue Plasma Needle likely damages CAM proteins so that cholesterol is not able to bind to the endothelium cell wall as easily, therefore meaning less cholesterol builds in artery Destruction of CAM  proliferation of free radicals (O, OH); previous research shows that plasma does disperse free radicals in a localized area. Amount of free radicals at a specific point depends on the distance from the plasma The Development of a Smart-Scanning Probe for the Plasma Needle, Ewout van der Laan

Project Goal Design and Build a Working Plasma-catheter Design and Build a Working Plasma-catheter –Construct functioning basic plasma needle prototype –Design catheter –Build catheter design incorporating functioning plasma needle –Characterize plasma-catheter prototype –Refine design to suit surgical needs

Requirements to Meet Goals Flexibility: Flexibility: –Tungsten electrode –Bending catheter should not affect gas helium flow –Insulating material Safety: Safety: –Minimal He flow –Possibly requiring a separating material between plasma discharge and biological tissue –No blood flowing into catheter and no bubbles going into bloodstream

Our Progress So Far Faculty Consultation Faculty Consultation –Welding Experts –High Frequency Electronics Technician –Cardiovascular Surgeon –Electrode Researcher Design of Test Rig Prototype Design of Test Rig Prototype Arranging for Experimental Setup Arranging for Experimental Setup –Commissioning of Glass Test Rig to Specifications –Arranging for Suitable Lab Space –Acquisition of Necessary Electronic Components –Acquisition of He Flow Equipment –Purchasing of Other Necessary Materials Design of Catheter Design of Catheter –Research into Operating Parameters –Brainstorm Potential Designs –Selection of Best Design

Plasma Needle Operating Characteristics  RF Frequency = MHz (universal)  P-P RF Voltage ~ V  Power Level ~ 100 – 400 mW  Needle Resistance = 1.1 ohm  Needle Capacitance = 28.8 pF  Plasma Resistance = 2 ohms  (Plasma discharge purely resistive)  Helium Flow = 0.1L/min  Minimum Ignition Voltage = 250 V

Plasma Needle Prototype Experimental Setup

First Test Rig Diameter of Tungsten Needle = 0.3mm Length = 5cm Material: Glass glass teflon coating tungsten helium RF 5 cm 2 mm

Revised Test Rig Modifications: 1)Lengthened Input Opening 2)Enlarged Input Diameter Hypodermic Needle Teflon Coating for Needle Glass Electrode's Teflon Coating Tungsten Electrode 50 mm 35 mm 2 mm 58 mm Electrode coating Needle coating Electrode Hypodermic Needle Helium flow 25 mm 4.3 mm Shaft Length: 5 cm Outer Diameter: 4 mm Inner Diameter: 2 mm Electrode Diameter:.3 mm

Teflon Needle Insulation Stainless Steel Hypodermic needle Tungsten electrode Teflon Electrode Insulation 10 mm Teflon overlap 25 mm needle tip RF Detailed View of Electrode Input

Function Generator (Courtesy of our Dutch colleagues) RF Signal: MHz Max Power Output: 10 W

Variable Matchbox Z-11 QRP Automatic Antenna Tuner  Manufacturer: LDG Electronics Inc.  Size: 5.0 x 6.5 x 1.3” enclosure  Tunes ohm loads  Tuning time:.1-3 sec 1.8 – 30.0 MHz Coverage 1.8 – 30.0 MHz Coverage Power range:.1-30 W Power range:.1-30 W

Z-11 QRP Automatic Antenna Tuner  Config: Switched “L” network  Microprocessor Controlled Inductor range: 20 uH Inductor range: 20 uH Capacitor range: 2700 pf Capacitor range: 2700 pf

Ramsey QRP Power Meter   Continuous measurement from 1µWatts to 50Watts  Allows measurement of both forward and reflected power

Helium Source and Flow Meter  Helium on hand in EE Welding Lab  Flow meter is calibrated for really small flows  External needle valve possibly needed

CostsItemCost RF Generator $0 Ramsey QRP Power Meter $ LDG Z-11 QRP Autotuner $ Cole-Palmer Flow Meter $179 Electric Connections $23.24 Tungsten Wire $3.55 Teflon Tubing $5 Hypodermic Needles $66 Glass Test Rig $50 Sum$617.69

Catheter Designs 5 cm Electrode coating Electrode Hypodermic Needle 20 mm 35 mm 2 mm Helium flow 4.3 mm Flexible Catheter (end view) Potential Internal Catheter Configurations

Immediate Goals (through beginning of April) 1.Construction of plasma needle prototype  Assess need for external needle valve  Construct experimental setup in EE Welding Lab  Run simulation and make necessary modifications 2.Contact Coordinating Group  Clarify necessary parameters for plasma characterization  Confirm parameters for final catheter design for use in rabbit test subjects  Establish communication with researchers planning to conduct animal testing 3.Catheter Design Work  Continue discussions with local medical professionals  Meet with Vanderbilt Catheter Lab specialists  Construct catheter prototype  Conduct laboratory testing to characterize catheter

Timeline DecemberJanuaryFebruaryMarchApril Gas Plasma & Catheter Research Construction of Functioning Plasma Needle Prototype Research & Design of Catheter Catheter Construction Physical Testing and Refinement of Plasma Catheter

Our Dutch Counterparts Willem-Jan van Harskamp, Applied Physics Vivian Roode, BME Gijs Snieders, BME M. van Vlimmeren, BME Advisor: Dr. Eva Adamowicz

Level of Development of Plasma Needle Technology Completed: Evaluation of the electrical characteristics of the plasma needle Evaluation of the electrical characteristics of the plasma needle Sensing the gap width by monitoring the discharge power consumption Sensing the gap width by monitoring the discharge power consumption Adapted positioning sensor Adapted positioning sensorCurrent: Design Plasma-Catheter Design Plasma-CatheterFuture:  Testing in animal blood vessels