Air Plasma Sterilization Device with Plasma-in-Lumen Technology

Abstract
Flexible endoscopy is widely used in diagnostic and therapeutic procedures for digestive diseases. However,
current endoscope sterilization technologies can be labor intensive, have high health and environmental
impacts, or have constraints in endoscope dimensions. Specifically, the mainstream approach Ethylene Oxide
(EtO) is facing significantly tightened regulations due to its high toxicity and carcinogenicity, and alternatives
such as Vaporized Hydrogen Peroxide (VHP) technologies are unable to sterilize lumens with >1 m length while
suffering from moisture-induced sterilization failure.
To tackle the challenge, Advanced Cooling Technologies, Inc. develops a novel dry air plasma sterilization
system that can perform automated endoscope sterilization without lumen length constraints or toxic gas
emission. Major innovations include 1) Sheet plasma reactor design that is embedded in a flexible pouch for
enhanced sterilization and combined storage; 2) Plasma-in-Lumen technology that directly delivers sterilant into
the lumens with arbitrary length; and 3) Chamber-free compact system design that allows a centralized control
unit to operate multiple pouches with a flexible sterilization scheduling. Further, the system is compatible with
various gas sources, including dry air, oxygen-rich air, and VHP for future commercialization.
In Phase I, we conducted a series of prototype development on both the component (pouch reactor and Plasma-
in-Lumen technology) and system levels to demonstrate the feasibility of the concept. The
sterilization/disinfection of the medical devices was successfully confirmed by the industrial field-standard self-
contained biological indicators (SCBIs) inoculated with G. stearothermophilus spores combined with process-
challenging devices (PCDs). Our work is the first in the world to successfully confirm air plasma
sterilization via SCBI and PCD. We also evaluated alternative gas sources to achieve a sterilization cycle time
shorter than that with the VHP system.
In potential Phase II, our goal is to develop a full-feature system that can achieve reliable sterilization of
endoscopes and other medical devices. Four Aims are strategically designed to achieve this goal: Aim 1) Build
a complete sterilization system with all the peripherals including a high-quality, reusable pouch with sheet plasma
reactors, Plasma-in-lumen reactors, and all safety and automation components. Aim 2) Perform and validate
consistent sterilization performance and long-term material compatibility. Aim 3) Develop high-throughput
operations. Aim 4) Explore alternative gas sources.
The recently tightened EtO emission regulation provided a unique commercialization potential for alternative
approaches such as plasma. Our technology can also be used in other applications such as planetary protection
for space missions, etc., further expanding commercialization opportunities with simplified regulatory pathways.

Grant Number: 2R44FD007709-02
NIH Institute/Center: FDA
Principal Investigator: Prawal Agarwal