Tetra (TM-20); Tetra (TM-50)

The Tetra Micro Infusion System is a battery-powered, reusable subcutaneous infusion pump designed for home and hospital use in adults and children 2 years and older. It delivers prescription liquid medicines, specifically Hizentra (immune globulin), by applying controlled pneumatic pressure to a syringe connected to sterile patient administration sets. Two models are available: TM-20 for 20mL syringes and TM-50 for 50mL syringes (or smaller sizes with an adapter).

The device uses a pneumatic pump to apply controlled pressure (2.50–7.00 psig) to the syringe gasket with five discrete pressure settings. It incorporates embedded firmware and microcontroller-based control, a rechargeable lithium-ion battery, LED and audible notifications for status and alarms, and a membrane keypad interface. Unlike the primary predicate (SCIg60) which uses a mechanical spring, the Tetra Micro employs battery-powered pneumatic control; like the secondary predicate (Crono), it uses software control and electronic feedback. Flow rate is not directly measured but determined by applied pressure, fluid viscosity, and downstream resistance.

Not stated in this summary.

Substantial equivalence is established through combined comparison to two predicates. The primary predicate (SCIg60, K240148) is equivalent in delivery method—both apply pressure to displace syringe fluid through passive administration sets without direct flow measurement. The secondary predicate (Crono S-PID 50, K091042) supports equivalence in battery-powered, firmware-controlled architecture and electronic feedback systems. Although the Tetra Micro uses pneumatic rather than mechanical (spring) or motor-driven pressure, the functional outcome, syringe-based delivery mechanism, compatible administration sets, and comparable flow characteristics demonstrate safety and performance equivalence. Non-clinical testing (infuser pressure, drug-device compatibility, flow verification, electrical safety, software validation, and usability) supports this determination.