The Application of Plasma Sterilization for SUDs

1. The Application of Plasma Sterilization for SUDs A novel Non-thermal Atmospheric Dielectric Barrier Discharge Ribbon Electrode MEM-031 Shawn Anderson William Borrell John Mattero Joseph Neal Royston Rodrigues Advisors: Dr. Y. Cho Dr. A. Fridman

2. The problem: Preventing pathogenic contamination • Bacteria are everywhere and surface contamination is practically unavoidable • Contaminated medical and surgical instruments can easily transmit bacteria which, leading to potentially fatal infections • Sterilization inactivates potentially harmful microorganisms +

3. Sterilization and Current Techniques • Electron Beam • Gamma Radiation • Ethylene Oxide • Thermal (Autoclaving) • Most popular • High temperatures and pressures denature proteins and kill bacteria

4. The Problem With Current Sterilization Techniques • Electron Beam • Very expensive, dangerous • Gamma Radiation • Ethylene Oxide • Long duty cycles • Toxic residues absorbed by materials • Thermal (Autoclaving) • Not applicable for heat sensitive materials • Some strains of bacteria are unaffected • Temperatures of 121°C are energy expensive and dangerous

5. Advantages of Plasma Sterilization • Faster • Experimentations of different treatment times shows a 6 log reduction in less than ten minutes • Safe for all surfaces and materials • More energy efficient • Power ratings less than that of a light bulb • Relatively Nontoxic • The only toxic byproduct is ozone, which can easily be removed • Inactivates the hardiest of bacteria • The inherent mechanisms of plasma sterilization are almost impossible for bacteria to adapt to*

6. What is Plasma • Plasma – 4th state of matter • Ionized gas • Depending on how energy provided can be thermal or non-thermal (cold) plasma • Created when high voltage is applied6 • Charge builds up on surface • Electrons that enter region form electron avalanche • Advantage as produces high energy electrons directly

7. How Do Plasmas Sterilize • Inactivation kinetics are not absolute • Current theories include • UV radiation • UV radiation can cause DNA damage or surface modifications which activates cell death mechanisms • Heat • Streamers produce temperatures of up to 1eV or 2.3x105 K • Charged particles • Electrons and positively/negatively charge ions • Direct and indirect effects of Reactive species • O, O2, O3, OH, NO, NO2 compromise bacterial cell wall components

8. i(+) NO OH e(-) i(+) O2(1Δg+) e(-) O3 i(+) i(+) O2(1Δg+) e(-) So, What is This Safe Direct Plasma?Dielectric Barrier Discharge (DBD) 10-30 kHz (continuous) 0.1-10 kHz (pulsed) 10-30 kV 0.5-5 mm gap 0.1-10 cm2 electrode 0.01-2 W/cm2 plasma power Electron Temperature: 10,000-20,000 K Temperature of Ions and Neutrals: 300 K (room) Plasma Density: 10^12 cm-3 Electron Density in Streamer: 10^13 cm-3 Continuous wave Microsecond pulse Nanosecond pulse

9. How Does DBD Plasma Sterilize? Major Bio-Active Components • Heat & UV inactivation is negligible • ROS and charged particles as the primary sterilants • Rate of ionization • keo - Collision Rate coefficient of electrons and neutral atoms, • I – activation energy • Te – electron temperature

10. DBD Plasma Sterilization 0.5 0.5 0 0 2.5 μm μm 0 0 Horizontal distance: 1.074 μm Vertical Distance: 463.45 nm Horizontal distance: 531.46 nm Vertical Distance: 108.39 nm

13. Electrode / Power Source Specifications • SCSI Cable • Silver wires, 1.0mm spacing • Teflon® insulation • Varying length • Surface Power Density

14. Design Constraints • DBD Plasma – Ribbon Cable Electrode • Table-top device • Minimal moving parts • Uses existing DPI power source • Ozone filtration • Safe to use

15. Our Product • A novel application for our method of sterilization • Self-contained box • Effective in facilitating sterilization of SUMD’s • Highlights the versatility of the plasma technology

16. The NTAP Sterilization Box • Simple design • Easy to use • Easy to manufacture • Effective in sterilization

17. Manufacturability • Plasma dictates usable materials • Simple design – easily reproduced on larger scale • Electrode requires active visual inspection • Combination of CNC Machining and human assembly

18. On the horizon… • Main goal - proof of concept • Our device - 1st Generation prototype – open to alteration • Novel application of our method • Can be scaled up or down • Innumerable alternate applications for this technology

19. PROTOCOL

20. EXPERIMENTS • What can our box do????

21. DEMO

22. Production

23. REPROCESSING SINGLE-USE MEDICAL DEVICES • Single-Use Medical Devices (SUD) • Scalpel handles, forceps, scissors, speculums, etc. • Defined as used, open, or expired • FDA and MDUFMA • Validated sterilization procedures must accompany 510K submissions • Requires similar standards as OEMs

24. WHY REPROCESS • If 1-2% of all SUDs were reprocessed, savings of $1,000,000,000/yr • Up to 50% savings when reprocessing once • 10 Million tons of waste diverted from landfills each year • Increased reliability

25. COMPETITIVE ADVANTAGES • Size • Scalable to large container size • Possible conveyor belt mechanism with automated sterilization • Efficacy • Proven to kill D. radiodurans, E. coli • Short duration exposure times • 30sec to 10hrs • Safety • Runs off 110V wall power supply • Non-thermal plasma safe to touch

26. SENIOR DESIGN BUDGET

27. Proposed vs. Actual Budget

28. Plasma Medicine Research Team College of Engineering College of Medicine College of Arts and Sciences School of Biomedical Engineering

29. Dr. Young Cho Dr. Alexander Fridman Dr. Greg Fridman Moogega Cooper Drexel Plasma Institute

30. Thank you!

31. REFERENCES – ADD THESE WITHIN THE PRESENTATION (CITE FIGURES) 1 http://www.myendosite.com/cms/files/July_1998_ID478.pdf • http://www.unc.edu/depts/spice/dis/ICHE-1996-Feb-p87.pdf • http://www.devicelink.com/mddi/archive/02/09/003.html • http://books.google.com/books?id=3f-kPJ17_TYC&pg=PA351&lpg=PA351&dq=plasma+sterilization+medical+devices&source=bl&ots=KkCpEv8PFZ&sig=hvTIRX2UtewsEEo0qgKqcfs8ugQ&hl=en&ei=7P2tSfHpCIiSngeElojDBg&sa=X&oi=book_result&resnum=7&ct=result • http://www.swri.org/3pubs/ttoday/Spring96/ttoday2.htm • http://www.gregfridman.com/publications/documents/STAR-RyanRobinson.pdf • Laroussi, Mounir. "Low Temperature Plasma-Based Sterilization: Overview and State-of-the-Art." Plasma Processes and Polymers 2 (2005): 391-400. • Fridman, Gregory, Peter I. Lelkes, and Kenneth Barbee. "Physical and Biological Mechanisms of Plasma Interaction with Living Tissue." Prepublication (2007).