University of Michigan

Smithsonian Astrophysical Observatory

Timothy Chupp

Kevin P Coulter

Robert C Welsh

Ronald Walsworth

Matthew S Rosen

Scott D Swanson

Eduardo Oteiza

A system, and corresponding method, that interfaces with a gas polarization system to deliver a polarized noble gas to a subject for inhalation. Large volumes of polarized noble gas are obtained by repeated production/freezing cycles of a spin-exchange system. A storage cylinder is provided for storing a polarized noble gas. A gas delivery line is coupled to the storage cylinder and selectively delivers the polarized noble gas to the storage cylinder, and from the storage cylinder to the subject. A vacuum means is in communication with the gas delivery line for evacuating the storage cylinder in the gas delivery line prior to the noble gas being delivered thereto. A plurality of non-metallic gas delivery valves, located between the gas delivery line and the vacuum means, selectively control communication between the vacuum means and the polarized noble gas to minimize depolarization of the polarized noble gas during delivery of the noble gas to the subject on a breath-by-breath basis, or at a constant delivery rate. Control of remotely activated pneumatic valves allows complete automation of the polarization/accumulation/storage/delivery cycle for use in a low maintenance commercial device suitable for clinical and research applications. The polarization stage can be optimized for a particular noble gas species and particular application by the specific programming of the control electronics or computer.

Polarized gas delivery system/method

A method and system for producing polarized .sup.129 Xe gas in an economical manner, allowing the polarized .sup.129 Xe gas to be used commercially in research and clinical applications. The production system of the present invention includes a holding tank for holding an unpolarized xenon gas/nitrogen gas mixture. The holding tank is in communication with a temperature controlled polarization chamber. A wide spectrum high power light source such as a diode laser array is in communication with the polarization chamber. The alkali metal vapor is optically pumped by the light source. The polarization chamber, which contains a given quantity of an alkali metal and its associated vapor, receives the gaseous mixture from the holding tank. The optically pumped alkali metal vapor atoms then collide with the xenon gas atoms, thus polarizing the xenon atoms. The entire gaseous mixture expands out of the polarization chamber into a device that separates the alkali metal vapor atoms from the polarized .sup.129 Xe atoms. The polarized .sup.129 Xe atoms are then controllably output to a system/user interface for application purposes.

Method and system for producing polarized .sup.129 Xe gas

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Ann Arbor, MI, United States of America

Timothy Chupp