The autoinjector is becoming an increasingly popular choice for patients and doctors wishing to replace the traditional injection method. However, manufacturers themselves require lengthy iterations in the design process to determine the spring that produces an ideal injection time. Instron's solution to this challenge bypasses the need to test multiple springs, using the advanced control capabilities of ElectroPuls^® to produce a unique spring simulator.

Instron solves the challenge of testing multiple springs using Modal Control, an advanced feature of the 8800 controller that creates a composite channel, allowing the applied load to vary with actuator position — representative of an actual spring.

The user simply specifies the initial preload and spring stiffness. The system then adjusts itself based on the actual load seen by the syringe, allowing the user to determine whether the chosen parameters for spring stiffness and preload have yielded an ideal autoinjector dispensing time for a given drug.

This unique combination of features within WaveMatrix3^™ software allows manufacturers to quickly establish which spring would be suitable for a given autoinjector, without the need for tedious physical testing of the springs themselves.