The Re-design of a BetaseronInjector
Problem: A non-user friendly medical device
We used Task Analysis to ensure that any changes made to the injector would not create further problems.
TASK ANALYSIS
RE-DESIGN
“Task analysis is defined as any process of assessing what a user does and why, step by step.” (BIOE 2580 Course Notes)
We video recorded 6 people to study the sequence of steps
necessary to use the product.
4 females, 2 males
Within the ages of 12 – 40 years old
All of the users were unfamiliar with auto-injectors except for one subject who takes daily insulin doses.
People made several mistakes
They all made the same mistakes
Where to place the syringe?
Correct placement of syringe
How people were doing it
The blue cap was left attached in the syringe assembly.
Several small errors leave the user wondering if things have been done correctly or not.
That causes unnecessary stress, feelings of uncertainty, confusion and frustration.
It is always a long tedious process for experienced users.
How to push the button?
At first attempt user implemented a downward pulling of the button rather than pushing it.
“Now, holding the blue Mixject adapter cap, connect the syringe to the open end of the adapter by carefully turning the syringe clockwise until the two pieces are connected. It shouldn’t take much force. The syringe system is now assembled.”
LONG PARAGRAPHS
POOR RESULTS
Do people tend to assume things are done one way or the other instead of how they are really supposed to be done?
Do people fully read long paragraphs in instruction manuals?
We should…BUT what if the user does not do it?
Is the injection going to be delivered safely? NO
✗ ✗
✔
The Redesign of a user friendly Betaseron Injector
Changes to the Reconstitution Process
& Instruction Manual
Indicator window
Metal sheet
Original Design
Twist and push
1) Twist
2) Push
Overview
Technical Details
Pushes the needle into the
skin(Penetration
Spring)
Contact ring attached to Penetration
Spring(Blue Ring)
Pushes piston of syringe, delivers
medicine(Injection Spring)
Holds Injection Spring
compressed(Light Blue
Piece)Purple Ring:
-Pushes Green ring
down
-Pushes Light Blue
Piece
Green Ring:
Holds Syringe
Purple Ring Springs:
Store Energy
Smallest Springs:
Weaker than the friction
coefficient of skin
Safety Mechanism,The only feature kept
from original
You cannot push thebutton if you did not
mean to.
The buttonHas been pressed
The ring has beenreleased.
Notice the springsIn their relaxed
position
NOT TO SCALE!!
The springs have nowbeen compressed
inserting the needle and storing energy
The blue ring has already come to a
relaxed position
Sky blue piece is pushed triggering injection
Springs rise with theStored energy
Injection Spring is Released.
Injection proceeds
The piston of theSyringe is pushed by the yellow piece
Insertion of needle Injection
NOT TOSCALE
The purple feature loads the springs making the injectorReusable.
Twist and push
1) Twist
2) Push
SEPARATE MECHANISMS WILL ALLOW CONTROL OF
THE PENETRATION FORCE AND CONTROL OVER THE
INJECTION RATE, MAKING THE INJECTION LESS
PAINFUL.
Changes to the Reconstitution Process
& Instruction Manual