2. Biofilms
Created by free-
floating bacteria
that adhere to a
surface
Form a complex
and layered
community with
extracellular matrix
Biofilms then
create more free-
floating bacteria
3. Biofilm Resistance
Resistant to:
antibiotics
immune response
Typical response
to biofilm growth is
to dispose of the
infected product
4. Biofilms and Health Care
Formation on
catheters (urinary,
heart, respiratory,
intravenous etc.)
Prosthetic valves,
artificial hips, teeth,
contact lenses
CDC reports biofilms
are responsible for
65% of infections
5. Biofilms and Contact Lenses
Improper cleaning
methods by users can
lead to biofilms forming
on contact lens cases
Rates of contamination
on contact lens cases
vary from 24% to 81%
Contact lens
contamination can lead
to microbial keratitis,
conjunctivitis,
staphylococci
6. Project Scope
Design a product that can destroy biofilms on
contact lens cases
Focus on biofilms that cause microbial keratitis
Portable, handheld device
Reasonable application time (<1hr)
Biofilm inactivation rate of at least 95%
7. Existing Solutions
Case cleaning happens
as a consequence of
lens cleaning
Heat
Hydrogen Peroxide
solutions
Multipurpose solutions
Silver impregnated
cases to dissuade
biofilm formation
8. Existing Solutions
Purilens
Magnetic pedal
on a flexible arm
is used to agitate
the saline
solution and
loosen deposits
from the lenses
UV light (253.7
nm) is used to
disinfect the
lenses, case,
and saline
solution
15 minute
application
period
Novelens
Two chamber case
that keeps lens
used solution
(containing
deposits) separate
from fresh solution
during the
disinfection process
to discourage
biofilm formation
QuickPure
Battery-powered
device which
generates ozone as
needed from the
oxygen in air and
bubbles it into
barrel to clean and
disinfect the lenses
and the case
3 minute
application period
9. Existing Solutions
Johnson & Johnson
Vision Care
A patent for a lens
storage case that uses
disinfecting UV
radiation to clean
lenses and the case
The Compliance Case
Co
A patent for a limited
use, self destructive
contact lens case
case leaks in a pre-
determined fashion to
alert user of end point
of safe utilization
10. Design
Specifications/Requirements
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
13. Design Schedule
November
2nd – Narrow Physical Design
8th – Contact Manufacturers
10th – CAD model of Design
15th – List of Materials
16th – Design Verification
22nd – Final Paper Draft
29th – Final Paper Revision
December
2nd – Final Presentation
4th – Final Report Due
14. Organization of Team
Nkele
Consumer Liaison, Lead Ergonomics Designer
Deborah
Materials Expert, Lead Mechanical Designer
Nick
Time Management, Lead Electrical Designer
Shared
Client Contact
System Integration
Informational Research
Risk Management
Website Upkeep
Strong extracellular matrix makes highly resistant to antibiotics. The extracellular matrix prevents molecules from passing through to the bacteria, even molecules as small as hydrogen peroxide do not have a strong effect on biofilms. Biofilms also have a much slower growth rate making antibiotics more ineffective. Many biofilms also exhibit over expression of multiple drug resistant pumps which make it even harder to destory.
Biofilms area serious problem in health care because they can form on many types of catheters such as urinary, heart, respiratory, and intravenous just to name a few. Biofilms can also form on prosthetic valves, teeth and contact lenses. The CDC reports that biofilms are responsible for around 65% of nosocomial infections. The formation of biofilms on catheters and valves can lead to chronic infections or chronic inflammatory responses in patient. The current protocol is to just have an emergency surgery to remove and replace the infected valve or catheter which not only raises the cost of health care for the patient but can also further weaken the patient’s immune system. Formation can lead to further tissue damage in the patient
There are 38 million contact lens wearers in the US and 138 million contact lens wearers worldwide. Poor cleaning habits can lead to biofilm formation on contact lens cases. The rate of contamination varies from 24 to 81%. \1 in 3 users clean their contact lens case monthly even less often. Contact lens contamination can lead to a number of infections and disease such as conjunctivitis (pink eye), saphylococci, and microbial keratitis. Microbial keratitis is the most severe of these infections which is the inflammation of the cornea and is specifically related to contact lens use and improper cleaning methods. There is no universal regimen for cleaning these contact lens cases or product that prevents that cleans biofilms off of contact lens cases.
Contact lens case disinfection is often thought of as a consequence of contact lens disinfection because it is assumed that lens cleaning and disinfection solutions also clean and disinfect the case. Cleaning with heat is the least effective and currently not used because it can distort the contact lens Currently the existing solutions involve hydrogen peroxide solutions or multipurpose solutions that you would find at walgreens. These solutions you normally just soak and wipe them down. Regarding contact lens cases some have silver incorporated into the biomaterials to make the surface hydrophilic to dissuade biofilm formation, but obviously this is a problem for people who are allergic to silver. These solutions rely a lot on user compliance. A study showed that only 26% of people cleaned their contact lens cases daily and one in three clean their case monthly or even less. We hope to create a product for this niche.
Purilens is designed to clean the lends and case without the use of solution. The process only takes 15 minutes.Novelens claims to keep used solution deposits away from the fresh solution while in the case to discourage biofilm formation.Finally ,QuickPure is a battery powered device that generates ozone to clean and disinfect the lens.
In addition to the aforementioned solutions, there are a couple of patented design solutions. The Johnson and Johnson vision care uses UV radiation to clean the contact lens case and contact lens. The Compliance Case corporation has a “self-destructive” case. So the case will leak if there is a change in environment in the case and alert the user that the case needs to be changed. Both are potential embodiments of the design
Needs to cost $60 for us to make
To measure the efficacy of our product, we will be using the following equation where CFU stand for colony forming unit.Similar power consumption to a videogame player we estimated the product to have a power output of around 0.25kW. The 0.099 dollars/kWhr is the national average for power draw.Conversational speech is 70dB
I’m the consumer liason and lead ergonomics designer so I will draft the interview questions for contact lens users and lead the interviews. I will also focus on making sure that the design of the product contributes to easy and effective use by the consumer. Deborah is the materials expert and lead mechanical designer so she will focus on the physical mechanisms and design of the product. Nick is the lead electrical designer and time manager. He will focus on creating functional circuitry and ensure that the team stays on track. As a group we will all stay in contact with our client through email. We will all update the website and perform risk management after integrating all aspects of the project.