SBIR-STTR Award

A use has recently been proposed for hyperpolarized noble gases as an MIRI contrast enhancer for e.g. MRJ of the lungs and other vacuous spaces. In all applications using hyperpolarized gases, it is important to measure its polarization. This is especially the case for hyperpolarized gases delivered from a central facility where there is the possibility of depolarization in transit. The purpose of this Phase I SBIR application is to design and build a portable instrument that can measure the polarization of any hyperpolarized gas, a hyperpolarimeter. We use a proprietary method that does not depolarize the gas nor require a nuclear magnetic resonance machine. It probes the gas with a magnetic field not much stronger than circuit noise at a frequency different from its magnetic resonance frequency. The principles and details of its operation are the subject of a patent application. This will be the first portable instrument to easily and precisely measure gas polarization. PROPOSED COMMERCIAL APPLICATION: This device will be useful to measure the degree of polarization of any hyperpolarized gas delivered to a hospital/clinic for use in enhanced MRI. It can also be used to control the degree of polarization delivered to a patient. In anticipation of the growing usefulness of hyperpolarized gases, we estimate initial 2002 sales of 6,000 units for enhanced lung MRI alone.

This project is to develop an instrument to measure the polarization of a hyperpolarized noble gas, Helium- 3 and Xenon-129, for enhanced lung MRIs in a clinical environment. It is essential to have some means of measuring polarization at various stages in the handling of these gases, e.g. at production, storage, transport and administration to a patient. The instrument we propose will be portable, compact (about 6 in. cube), self contained and versatile, able to operate in several modes and in various environments, yet capable of being integrated in a larger system. Unlike presently used methods of measuring polarization, this is a direct measure of nuclear polarization that does not destroy any of the polarization of the sample being measured. It operates on the principle that two coupled resonant systems, in this case an electronic L-C circuit and the magnetically resonating nuclei, oscillate in unison in either of two frequencies, neither of which is the same as the magnetic resonant frequency of the nuclei. The system is made to oscillate at a very low amplitude, and polarization is derived from measurements of frequency. Since the magnetic field probing the nuclei is not much stronger than thermal noise, and at a frequency different from their resonant frequency, the nuclei are not disturbed. The program is to investigate different modes of exploiting this phenomenon (the splitting of the resonance), to devise protocols for efficient implementation, and to develop software to enable the instrument to operate automatically and in an intelligent user friendly manner; to design plug in modules to enable the instrument to work in a variety of environments; to calibrate the instrument to give a direct output of the polarization at the instant when it is measured for 3He and 129Xe, to package, test, and arrange the manufacture of a final model. MR imaging of the lungs and airways using hyperpolarized noble gases (3He and 129Xe) is particularly useful in the early diagnosis and management of, e.g. emphysema, asthma, cystic fibrosis, COPD etc., as it reveals, with zero radiation dose, information about morphology and functioning of the lungs, circulation and soft tissues, not available with other techniques.

Thesaurus Terms:
biomedical equipment development, clinical biomedical equipment, helium, magnetic resonance imaging, molecular polarity, polarography, respiratory imaging /visualization, xenon contrast media, magnetic field, portable biomedical equipment bioengineering /biomedical engineering, bioimaging /biomedical imaging