NMR instrument for testing for fluid constituents
First Claim
1. In a nuclear magnetic resonance spectroscopy apparatus for testing fluids for the presence of constituents, said apparatus being of the type in which a first magnetic field aligns 1 H protons to an initial position, and in which a second magnetic field is cyclicly energized and deenergized to cause alignment of the 1 H protons to a second position and realignment to said initial position, and in which the magnetic changes resulting during realignment are detected and analyzed, the improvement comprising:
- first magnet means comprising a pair of permanent bar magnets each including a north pole and a south pole,second magnet means for creating said second magnetic field, said second magnet means comprising a plurality of additively connected surface coils for both transmitting energization and sensing;
mounting means for mounting said first magnet means,said mounting means comprising a pair of spaced apart members for positioning said pair of bar magnets space apart with the north pole of each said bar magnet secured to one of said members and the south pole of each said bar magnet secured to the other of said members, said first magnet means, said second magnet means and said mounting means providing a cavity defining a test region therein for receiving a sample of the fluid to be tested,said first magnetic field being substantially uniform in field strength and direction throughout said test region;
said second magnet means being operatively disposed with respect to said test region for being magnetically coupled to the fluid sample to be tested;
first and second members connecting said pair of spaced apart members, said first connecting member including an aperture therethrough for access of said fluid sample into said test region;
circuit means for detecting and analyzing said magnetic changes;
said second connecting member having switch means operatively associated therewith for initiating operation of said circuit means;
a sample holder containing a standard sample of known concentrations of the constituents to be investigated;
said standard sample holder being initially disposed in said test region; and
means for biasing said sample holder to urge said sample holder toward said second connecting member and to initially locate said standard sample in said test region and capable of being operatively coupled to said second magnet means when said second magnet means is energized;
said switch means being activated in response to the movement of said standard sample holder out of said test region to contact and operate said switch means when said fluid sample to be tested is moved into said test region.
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Accused Products
Abstract
There is disclosed herein a nuclear magnetic resonance apparatus for testing body fluids for a constituent, for example, blood for glucose. The apparatus includes a principal magnet, a magnetizable coil, and a circuit for energizing the coil for energizing and realigning molecules and detecting changes resulting from relaxation of said field and analyzing said changes. The apparatus is compact and adapted to receive and test an extremity or vessel carrying a body fluid. The coil is constructed to be positioned adjacent the extremity or vessel to be tested. Circuit means are provided for energizing the coil to energize and realign molecules adjacent said coil, so as to permit molecules adjacent said coil to assume an aligned position and for sensing changes in position when the coil is deenergized, which is indicated by spectra having peaks corresponding to various molecular bonds. The circuit also includes means for comparing the actual value of a peak for a first constituent to a predetermined value for the peak of said first constituent and determining the actual value of a second constituent from a predetermined relationship between the values of the peaks for the first and second constituents. Specifically, predetermined water and glucose peaks are compared with the measured water and glucose peaks for determining the measured glucose concentration.
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Citations
1 Claim
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1. In a nuclear magnetic resonance spectroscopy apparatus for testing fluids for the presence of constituents, said apparatus being of the type in which a first magnetic field aligns 1 H protons to an initial position, and in which a second magnetic field is cyclicly energized and deenergized to cause alignment of the 1 H protons to a second position and realignment to said initial position, and in which the magnetic changes resulting during realignment are detected and analyzed, the improvement comprising:
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first magnet means comprising a pair of permanent bar magnets each including a north pole and a south pole, second magnet means for creating said second magnetic field, said second magnet means comprising a plurality of additively connected surface coils for both transmitting energization and sensing; mounting means for mounting said first magnet means, said mounting means comprising a pair of spaced apart members for positioning said pair of bar magnets space apart with the north pole of each said bar magnet secured to one of said members and the south pole of each said bar magnet secured to the other of said members, said first magnet means, said second magnet means and said mounting means providing a cavity defining a test region therein for receiving a sample of the fluid to be tested, said first magnetic field being substantially uniform in field strength and direction throughout said test region; said second magnet means being operatively disposed with respect to said test region for being magnetically coupled to the fluid sample to be tested; first and second members connecting said pair of spaced apart members, said first connecting member including an aperture therethrough for access of said fluid sample into said test region; circuit means for detecting and analyzing said magnetic changes; said second connecting member having switch means operatively associated therewith for initiating operation of said circuit means; a sample holder containing a standard sample of known concentrations of the constituents to be investigated; said standard sample holder being initially disposed in said test region; and means for biasing said sample holder to urge said sample holder toward said second connecting member and to initially locate said standard sample in said test region and capable of being operatively coupled to said second magnet means when said second magnet means is energized; said switch means being activated in response to the movement of said standard sample holder out of said test region to contact and operate said switch means when said fluid sample to be tested is moved into said test region.
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Specification