Eye Medication Applicator

Our goal is to design, fabricate, and test a product that will effectively deliver medication to the eye in a way that will appeal to a wider audience than products currently on the market. 
== Design Specifications ==
Our product must follow a number of guidelines
* Each application must deliver 0.5 mL of medication to the eye
* At least 90% of the medication must make direct contact with the eyeball
* The product must be usable for the average person between the ages of 8-85
* The applicator must be compatible with all prescription eye-dropper bottles
* The bottle will not be manually squeezed during use
* The user will not have to tilt their head back more than 10 degrees during use
* The user will not have to move their shoulder more than 15 degrees from resting position during use
* The user will not have to flex the ends of their fingers to more than 135 degrees inward from a straightened position
* The average user must be able to change bottles within 15 seconds
== Project Learning ==
The aim of our project is to solve problems related to the application of eye medication. We looked at any and all problems that may arise in using eye drops and narrowed our focus to four main issues. While these are all deemed important to our goals, not all of them will receive the same focus. These problems are ranked from most relevant to least relevant within our project goals.
* [Most Relevant] Lack of dexterity with users such as lack of neck and shoulder dexterity and inadequate fine motor skills
* Wasted medication as a result of inaccuracy or inappropriate dosage
* Inconsistent application approach as a result of ill-defined application methods for current products and misuse of products
* Undesirable reflexes such as anticipation, blinking, and uncooperative behavior
== Design Ideas ==
In the early stages of our project, we designed and printed a number of prototypes with different goals in mind. Each design has unique functions as well as advantages and disadvantages. Our current design utilizes and improves upon features from other prototypes such as the three listed below.
Picture 	Description	Pros/Cons
thumb|center|200px]|Focus: Fit and lack of maintenance]]	Angled Applicator
This was our first printed design.
The purpose of this design was to remove head tilt from eye-drop application.
To use it, the user tilts their back 45o and holds the cup over their eye.	Advantages:
::*Requires no sanitation
::*Form-fitting contact area
::*Applicator fits comfortably in-hand
Disadvantages:
::*Model is bulky and requires a large amount of material
::*Still requires head tilting
::*Requires great force to squeeze the bottle
thumb|center|200px]|Focus: Size and simplicity]] 	Nose-fitted Guide
This design was focused toward making the product as simple as possible.
The applicator was worn on the bridge of the nose.
The medication would be dropped into each hole corresponding to the left and right eye.
Holes on the ends of the device would then drip medication into the inner corner of each eye.	Advantages:
::*Compact and simple design
::*Can be used on either eye or both at once
::*Assists those with low shoulder dexterity
Disadvantages:
::*Head must be tilted back
::*Usage requires multiple steps
::*Nose fit varies too much
thumb|center|200px]|Focus: Simple use and good fit]] 	Angled Applicator with Nozzle
This design revisits concepts from our first angled applicator.
The eye cup helps keep the eye open and the nozzle allows the medication to squirt into the eye.	Advantages:
::*Light-weight design
::*Contours to fit over the eye
::*Simple usage
Disadvantages:
::*Requires squeezing the bottle
::*Does not mitigate head-tilt
::*Does not aid with joint dexterity
== Detailed Design ==
Our design consists of three major components - the casing, the button/head, and the internal pump and nozzle. The piping and nozzle are not shown, but the pump drives flow through the nozzle. The current nozzle was adopted directly from a commercial product - the final product will have a custom-made nozzle. The casing, button, and head will be injection molded from a soft polyurethane plastic with the internals positioned within the plastic as it sets.
Picture 	Needs	Specifications	Design Features
thumb|center|200px]|The casing that fits over the rest of the assembly]] 	
*Compact design suitable for storage
*Accommodates tubing and other necessary internals
*Possible to mold using silicon
*Contains a receptacle for a medication bottle	
*Fits 95% of hand sizes
*Requires no more than 10 seconds of hands-on observation to learn proper use	
*Simple shape keeps other components in place
*Interior flanges keep button from dislodging
*Tube stays open (no kinks) within the component
thumb|center|200px]|The button and head piece, which are directly connected]]	
*Holds the eye open during use
*Doesn't leak medication
*Possible to mold using silicon
*Activates the pump	
*Contours to >99% of human faces
*Fits standardized bottle sizes and nozzles	
*Moving eye cup aids in keeping the eye open during use
*Contours with the interior of the handle piece
*Large surface area makes it easy to press the button
thumb|center|200px]|The pump that delivers fluid to the nozzle]] 	
*The nozzle must spray or mist
*The nozzle, pump, and piping must connect as one piece
*The nozzle, pump, and piping must fit within the casing	
*Fixed diameter tubing - 1/16" fuel line
*Dispenses 0.05 mL with 0.0025 mL tolerance (5%)
*95% of medication enters eye	
*Pump delivers a steady and fine spray
*Receiving end allows medication bottle to screw in
*Pump requires minimal force to press
== Current Design ==
[[File:LeverAssembly.png|thumb|Right|200px]|The newest prototype assembly]]
Our current design is a modification of a previous model which can now be molded with polyurethane and silicon. An experimental mold has been completed as a proof-of-concept. The mold template was prepared using a 3D print of this design.
The design consists of multiple components:
*A casing that holds the rest of the components in place
*A button piece that slides into the casing, actuating the pump
*A pump that delivers a mixture of air and fluid to the nozzle
*A nozzle that delivers a fine and consistent spray (not shown)
*Contouring part that fits against the face (not shown)