Peter Kleinschmidt, Joe Helfenberger, Lein Ma, Leon Corbeille, Neal Haas BME 201 March 7, 2008

 Client: Dr. Carla Alvarado Center for Quality Productivity Improvement  Advisor: John G. Webster Dept. of Biomedical Engineering

 Hand sanitizing device  Importance of hand washing  Disinfectant formulation Emollients  Nozzles Type Location  Electronics (power supply) Computer based Integrated circuit Microcontroller  Future work  References/ Acknowledgements

 Kills vegetative bacteria and fungus  Sprays computer keyboard and hands with disinfectant  Disinfectant evaporates quickly and preserves skin integrity  Passive action  Minimal environmental mess  Fits in with workflow

 Hospital infections occur in 8-10% of all admissions.  Related to poor hand hygiene  Improvement is critical for reducing hospital induced infections

 Hand washing compliance in healthcare settings remains low.  Reasons why? Time Forgetfulness Accessibility

 Ethanol Widely used Antiseptic at 60% – 70% Dries hands very quickly  Emollients “Softeners”, moisturizers, etc. Aloe Vera, Vitamins and Minerals, synthesized

 Custom Mixture Designed to suit our model Time-consuming to research and create Unknown effectiveness  Commercial Product May not cooperate as well with prototype Easily test effectiveness Saves time and money Image: content/uploads/2006/10/purell_sanitizer_12oz.jpg

 Nozzles will be used to spay the disinfectant onto the keyboard and hands.  Factors to Determine What kind How many Location and orientation

 Mist-spray nozzles  Compressed air spray nozzles  Fogging nozzles Compressed air spray Fogging Mist-spray Images:

Determine where to put the nozzle(s) to cover the hands and the keyboard Spray should not effect the environment surrounding the keyboard

Control mechanism to operate spray of solution to keyboard – Electrical signal to power spray linear pump Needs to integrate with triggering method – E.g. Keystroke, IR sensors, Ultrasound Sensors

 Computer based controller Existing prototype runs off a LabView program  Integrated circuitry  Microcontroller Image: Image: Image: Created By Peter Kleinschmidt with PSpice Schematics V 9.1

Pros – Easy to program and easy to change – Good for demonstrating prototype functionality Cons – Expensive – Impractical for Hospital Environment – Cited issues with timing inaccuracies in existing prototype Design Ratings Developmental Cost 8 Mass Prod. Cost2 Flexibility8 Developmental Challenge 4 Implementation Difficulty 2 Total24 Rating Scale: 1-10 (1-Poor, 10- Excellent)

Pros: – Simple to construct: IC elements (e.g. 555 Timers), Resistors, Capacitors – Cheap Cons: – Not very flexible. Changes in functionality require new parts – More difficult to achieve fine tuned control Design Ratings Developmental Cost 8 Mass Prod. Cost9 Flexibility3 Developmental Challenge 2 Implementation Difficulty 9 Total31 Rating Scale: 1-10 (1-Poor, 10- Excellent)

 Pros: Versatile, easy to modify to usability considerations Accurate, Fine tuned control (within 1 ms control) Easy to integrate with different signaling options  Cons: Developmentally, moderately expensive (~$160) Design Ratings Developmental Cost 5 Mass Prod. Cost7 Flexibility8 Developmental Challenge 6 Implementation Difficulty 9 Total35 Rating Scale: 1-10 (1-Poor, 10- Excellent)

Design RatingsLabViewIC ElementsMicrocontroller Developmental Cost 885 Mass Prod. Cost297 Flexibility838 Developmental Challenge 426 Implementation Difficulty 299 Total Rating Scale: 1-10 (1-Poor, 10- Excellent)

 Program microcontroller  Assemble device  Test spray range  Test disinfectant’s effectiveness in microbiology lab with bacteria  Finalize/test device trigger

 Boyce, John M.; Pittet, Didier Guideline for Hand Hygiene in Health-Care Settings: Recommendations of the Healthcare Infection Control Practices Advisory Committee and the HICPAC/SHEA/APIC/IDSA Hand Hygiene Task Force, Recommendations and Reports. 51(16):  Voss A, Widmer AF. No time for handwashing!? Handwashing versus alcoholic rub: can we afford 100% compliance? Infect Control Hosp Epidemiol 1997;18:  Parker, Tara. “Why Hand Washing May Be Your Best Medicine.” New York Times. December 19, March 4,  Newsom SW. Pioneers in infection control. Ignaz Philipp Semmelweis. J Hosp Infect 1993;23: Acknowledgements  Dr. Carla Alvarado  Prof. John G. Webster  Prof. Willis Tompkins  Dr. Tosha Wetterneck  Fall 2007 Hand hygiene team