A Sensitive point

When a prominent biotechnology group wanted an automated system to test its new dial-a-dose drug-delivery pen, it turned to Innomech to help with its development.

The pen is used by children to intermittently and regularly self-administer a very high-value active pharmaceutical. In use, the device injects a needle into the skin to deliver a precisely metered amount of a drug, after which the needle is retracted.

The pen has four main active elements: the needle through which the medication is delivered; a spring-loaded contact cup that is pressed against the skin; a rotary dial used to set the required dose and to provide energy to fire an actuator; and the actuation mechanism itself.

Once a user has set the dose through turning the dial and depressed the actuator, the energy stored within an internal spring is released, firing the needle through the contact cup into the skin. The distance the needle travels is relative to the compression cup, so the needle is always moved relative to the skin surface, not the body of the device, to dispense the correct volume of medication to the patient.