The re-design of a non-user-friendly autoinjector

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

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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