Abstract:
Needle-free jet injection (NFJI) is a drug delivery technique that requires the application of a brief (10 ms to 100 ms) pulse of high force to pressurize a liquid drug and force it through the skin. To provide control over this force using an electric motor, high drive power is needed from a compact system. This work outlines the design process of an untethered power and motor drive system that is estimated to weigh approximately 2.5 kg, capable of supplying 1.6 kW at 210 V peak-peak. The device is used to drive a linear synchronous motor to deliver up to 31 large volume (1 mL) needle-free jet injections (NFJI) within a single recharge. The system architecture, gathering of detailed functional requirements, selection of energy storage, and the studies of power electronics and motor drive via system simulation are discussed. Inspired by electric vehicles battery boosted motor drives and cascaded interleaved boost converters for high step-up conversion ratio, the proposed design employs a battery-powered boost converter which then energize a 3-level inverter with the peak to peak voltage of 210 V. The design utilizes the latest gallium nitride (GaN) transistors as well as the latest lithium-ion capacitors (LIC) for energy storage. The power electronic topology introduced in this work is also adaptable for other high energy pulsed applications such as plasma generation, or MRI gradient coils.
