Electro-Optic Chopper for Advanced Airway Gas Monitors

Our goal is to develop a compact, inexpensive, electro-optic chopper for infrared (IR) light whichwill enable the manufacture of compact gas analyzers. The availability of this compact instrument willgreatly enhance monitoring of anesthetic and physiological gases. Choppers used in current generationinstruments typically consist of an electric motor and a spinning wheel. These are bulky, less reliable,and less accurate than electronic components, and they generate unwanted vibrations. Their sizeinterferes with placing analyzers as close to the patient as desired. Advanced designs for compact andreliable spectroscopic gas analyzers are dependent on the development of a chopper technology whichis compact and reliable. The electro-optic chopper consists of a ferroelectric liquid crystal (FLC) cell anda pair of specially designed IR polarizers. It will be compact, precise, reliable, and vibration free. Thepolarity of applied voltage controls whether the shutter is open or closed.The investigators haveexperimentally demonstrated the essential principles of the device. However, tn order to fully evaluatefeasibility they must determine the achievable optical efficiency, reliability, and cost. The investigatorswill address these issues in Phase I through tests of state-of-the-art FLC materials, prototype choppers,and the experimental manufacture of an innovative low-cost IR polarizer.