Fear of contamination
Becton Dickinson
Safety Needle
The trip from patient to sharps bin can be a precarious adventure, especially in a bustling emergency room. To eliminate the risk of accidentally sticking someone with a contaminated needle, we designed the syringe to retract its needle immediately after use. We also created a tamper-proof locking mechanism that prevents any additional use after the primary injection. Once the mechanisms were proven through a series of working prototypes, a battery of cast models were created to explore areas of comfort, understanding new technology applied to a familiar product, and a style that is consistent with BD’s high standards of design.
Revision
Humanfactors’ first foray into safety syringes was a series of innovative lockout concepts that focused on the rear of the plunger. While easy to engage and effective at preventing re-use, BD wanted a new lockout design that would engage automatically.
Concept Generation
Rather than maintain the rather bulky mechanisms required for a lockout atop the barrel, we began focusing on the barrel’s front end. Concepts explored various means of preventing access to the cannula - enshrouding it, rendering it useless, sending it up into the barrel…
Engineering
The most effective configuration proved to be enshrouding the cannula in a lockout sleeve. Once the dose has been administered, the plunger sets off what is essentially a chain reaction of spring-activated rotating and sliding concentric sleeves, one of which drops and locks over the cannula, preventing any re-use.
Functional Prototype
When dealing with such small details - miniature components that slide, spring, and rotate together in a tight volume - the only way to ensure viability is to fabricate and test. A series of prototypes were developed for design verification and validation. CAD simulations and FEA are invaluable tools for de-risking concepts, but there’s no substitute for a functional prototype.
