Syringe Driver Lock Box

Manufacturability, Functionality, 3D Printing

Design & Development


The design and development of an injection moulded medical part was created which reduced the cost of the part by 85%. Originally done to evaluate the use of additive manufacturing within a hospice for in-house manufacturing which was decided against due to technical knowledge and time required


Issues to Resolve


  • Hinge breaks due to distance from fulcrum to point of lift


  • Hinge can also be easily taken apart by pushing two pins out thus exposing any medication inside


  • Difficult to clean due to sharp corners


  • Extremely expensive


  • Needs to fit into existing bag


  • Needs to be very easy to assemble

Modelling & Testing


Multiple iterations of designs were tested and evaluated with the product inside to highlight areas of improvement. Different locks were utilised with designs planned around those to find the best possible solution. These were presented to the client with multiple meetings arranged to discuss any areas which may need to be designer differently. As an example, one design requirement which was highlighted was the need for the lock to be within the product

Final Design


The final design incorporated a living hinge to improve security, ease manufacturing and reduce assembly time and complexity. The design fits seamlessly into the existing bag and can house the different sizes of syringes required by the Syringe Driver. Information and buttons can easily be accessed and due to the simpler design with more curves introduced, cleaning has also been made easier. The internal lock provides security with ribs added to reduce flexibility. A 3 degree draft angle has also been included to ease manufacturing when injection moulding