Deborah Ohiani-Jegede Partners: Nkele Davis and Nick Xydis Group 24, Client :Brad Clay, bio Merieux
Biofilms are an aggregate of microorganism where cells are stuck to each other and/or a surface Can form contact lens cases due to improper cleaning/user non- compliance Contact lens contamination can lead to microbial keratitis, conjunctivitis, staphylococci which may require surgery
Usability Within 3” x 5” Weight: < 5 lb Operating time: < 1 hours Visual timer display Set up Time: < 30 seconds Sound during application: < 40 dB Autonomous system, turns on and off automatically Waterproof Economics Cost: < $200 (prescribed by doctor) Power Draw: <.25kWhr per application Effectiveness 95% biofilm destruction biofilm growth prevention No damage to lens case and lens Durability meets all other specification requirements after 5 years
Choose Disinfection Technology Disinfection Technologies Hydrogen Peroxide Solutions Heat Treatment Pulsed Electric Field Ultraviolet Radiation Sonication Atmospheric Pressure Room- Temperature Plasmas Construct Final Product Design
UV-C radiation ( nm) effectively stunts biofilm growth Penetrates bacteria to nucleus to irreversibly damage the DNA 254nm breaks molecular bonds of microsomal DNA
High frequency shaking (sonication) can disrupt biofilm by breaking up extracellular matrix and dislodging from surface Coupled with another method, could potentially make disinfecting more effective Sonication at 40kHz for 5minutes had success in previous literature
Apply high voltage between dielectric electrodes to ionize surrounding air Reactive oxygen species (O 3, H 2 0 2, O 2, OH - ) destroys biofilms via oxidation “Plasma needle” – high voltage to metal wire to ionize surrounding air
Tested UV radiation, UV + Sonication, Cold Plasmas Staph epidermidis - test bacteria o Common microbe on contact lens and contact lens cases o Biofilm forming strain chosen o Diluted bacteria to 1McFarland (3e8 bacteria/mL) Testing on polystyrene coverslips o Common plastic in contact lens manufacturing
UV-C radiation at 254nm produced using MaxLamp FIlter Three five-minute treatments biofilm on coverslip Streaked samples on agar plates in between trials Plates grown overnight in incubator at 36°C
Extremely effective in destroying biofilms Solution added to coverslip to prevent drying/warping
Prepared coverslip, placed in ultrasonic cleaner, and weighted down with bottle Treated for 5 minutes at 40kHz, then with 5 min UV Cycle repeated 3 times total Swab and plate samples after each treatment Plates grown overnight in incubator at 36°C
Small hole bored into petri dish cover contain plasma Generator at 30kV Three five-minute treatments of plasma Swab and plate samples after each treatment Plates grown overnight in incubator at 36°C
WeightUltraviolet Radiation Ultraviolet Radiation + Sonication Cold Plasma Efficacy5533 Safety4443 Durability4433 Cost3324 Speed of Use2543 TOTAL 7657
Motor engine to sonicate UV+Sonication Plasma
Deep UV light Single Button Timer Display Safety Interlock Door sensors LED Light Minimal light intensity of 30 microWatts/cm 2 30-minute application Side Panel Access Door
Nkele o Sonication and Mechanical Turbulence Expert o Lead Ergonomics Designer Deborah o UV Treatment and Biofilm Growth Expert o Lead Mechanical Designer Nick o Plasma and Electric-Field Treatment Expert o Lead Electrical Designer
November o 2nd - Optimizing Physical Design o 4th - Performing UV Wavelength Testing o 5th - Continued Wavelength Testing o 6th - Ensuring Optimal UV Application Technique o 7th - Evaluation of Experimental Results o 8th - Meet with Manufacturing o 10th - Computer Model of Design o 13th - Brainstorming compatible materials o 15th - Creating official List of Materials o 16th - Design Verification o 22nd - Final Paper Draft o 28th - Thanksgiving o 29th - Final Paper Revision December o 2nd - Final Presentation o 4th - Final Report Due o 5th - Celebratory Retreat
Questions?