Redesigning the EpiPen
Challenge
A final-year university team project to reduce the size of the EpiPen to encourage users to carry them more consistently.
Approach
I was the sole mechanical engineer working with product designers and biomedical engineers. I researched users’ pain points, read ISO standards, generated concepts, disassembled an autoinjector, conducted a usability analysis, carried out fluids and force calculations, and created a detailed CAD model on SolidWorks.
Outcome
The redesigned autoinjector is 37% shorter than the EpiPen and features an innovative mechanism where the spring surrounds the cartridge, making it easier for users to carry. I was awarded a grade of 94%, which was the highest in the year.
Skills demonstrated
Mechanism design, SolidWorks CAD, creativity, concept generation and concept schematics, understanding of medical device regulations and standards, leading a team, engineering assembly drawings, presenting skills, design for manufacture
Project background
The EpiPen contains epinephrine (adrenaline), which is used to treat anaphylaxis, an allergic reaction sometimes involving narrowing the airways. Anaphylaxis causes an average of 20 deaths per year in the UK. People who are prone to anaphylaxis must carry two adrenaline autoinjectors (AAIs) with them. The current EpiPen, which is the most popular AAI, is a large device which is one reason for 28% of young adults choosing not to carry them [1]. From primary interviews with AAI users, it was found that the large size of AAIs was the main ‘pain point’ reducing the likelihood of users carrying the AAI with them. A smaller device would encourage people to carry them more consistently, reducing fatalities.
I led this team project, which counted for 30% of a Healthcare Engineering module. All the work featured on this page was my personal contribution to the project.
The EpiPen is a large device which makes it inconvenient to carry. GETTY IMAGES
Understanding the regulations and standards
I researched the regulatory requirements to sell the AAI in the US and EU and the standards that would need to be followed.
An autoinjector is a class IIa medical device which means it is a medium-low risk device [2]. Non-reusable autoinjectors containing epinephrine in a single integrated package are classed as medicinal products in the EU, based on EU Directive 2001/83/EC [3]. In the US, non-reusable autoinjectors containing epinephrine in a single integrated package are classed as combination products, which means the device and pharmaceutical parts can be split apart. Thus, a shorter time to market is possible in the US than in the EU. This information helped plan the development timeline.
Key ISO standards for developing the epinephrine autoinjector include ISO 11608 (numbers 1,2,3 and 5) which details guidance on developing needle-based injection systems. These standards helped inform the design specification.
Disassembling a current device
I disassembled an AAI currently on the market to understand its operation, materials, and manufacturing methods.
Generating concepts
I generated several concepts and created schematics of them.
Developing the chosen concept
I created a CAD model on SolidWorks which showed each component and the mechanism operation. I considered manufacturing methods and materials and ensured the device met ISO standards. I used off-the-shelf components where possible such as the needle, cartridge and plunger stopper to reduce development time. I conducted fluids and force calculations to choose a suitable spring.
Ensuring the device can be used by everyone
I created a model of the device and tested its form factor with large and small hands to ensure it could be usable by people with hand sizes between the 5th percentile of women and the 95th percentile of men.
Outcome
This compact AAI solves the size issues of the EpiPen and could be further developed and launched onto the market. The innovative mechanism which enables the compact form factor could become intellectual property. I wrote a report on the project and gave a presentation to Team Consulting which both contributed to my grade of 94%.
[1] "Statement regarding the inquest of Dylan Hill," 20 September 2017. [Online]. Available: https://www.anaphylaxis.org.uk/statement-regarding-inquest-dylan-hill/.
[2] " COUNCIL DIRECTIVE 93/42/EEC of 14 June 1993 concerning medical devices," Official Journal of the European Union, no. L 169, pp. 1-60, 1993.
[3] "Directive 2001/83/EC of the European Parliament and of the Council of 6 November 2001 on the Community code relating to medicinal products for human use," Official Journal of the European Communities, no. L 311, pp. 67-128, 2001.
[2] " COUNCIL DIRECTIVE 93/42/EEC of 14 June 1993 concerning medical devices," Official Journal of the European Union, no. L 169, pp. 1-60, 1993.
[3] "Directive 2001/83/EC of the European Parliament and of the Council of 6 November 2001 on the Community code relating to medicinal products for human use," Official Journal of the European Communities, no. L 311, pp. 67-128, 2001.
