Government of the United States of America, as Represented by the Secretary of Commerce

The United States of America, as Represented by the Secretary, Department of Health and Human Services

John M Moreland

Stephen Dodd

Gary Zabow

Alan Koretsky

William P Dube

Stephen Russek

Elizabeth Mirowski

Loren F Goodrich

Paul Rice

Alan Korelsky

The present invention relates to a magnetic resonance structure with a cavity or a reserved space that provides contrast and the additional ability to frequency-shift the spectral signature of the NMR-susceptible nuclei such as water protons by a discrete and controllable characteristic frequency shift that is unique to each MRS design. The invention also relates to nearly uniform solid magnetic resonance T* contrast agents that have a significantly higher magnetic moment compared to similarly-sized existing MRI contrast agents.

Magnetic microstructures for magnetic resonance imaging

The present invention relates to magnetic contrast structures for magnetic resonance imaging, and methods of their use. The contrast structures include magnetic materials arranged as a pair of disk-shaped magnetic components with a space between a circular surface of each disk shape, or a tubular magnetic structure, a substantially cylindrical magnetic structure, a substantially spherical shell-formed magnetic structure, or a substantially ellipsoidal shell-formed structure, each defining a hollow region therein. The space and/or hollow region in the contrast structure creates a spatially extended region contained within a near-field region of the contrast structure over which an applied magnetic field results in a homogeneous field, such that nuclear magnetic moments of a second material when arranged within the spatially extended region precess at a characteristic Larmor frequency, whereby the contrast structure is adapted to emit a characteristic magnetic resonance signal of the magnetic material.

The present invention relates to a magnetic resonance structure with a cavity or a reserved space that provides contrast and the additional ability to frequency-shift the spectral signature of the NMR-susceptible nuclei such as water protons by a discrete and controllable characteristic frequency shift that is unique to each MRS design. The invention also relates to nearly uniform solid magnetic resonance T* contrast agents that have a significantly higher magnetic moment compared to similarly-sized existing MRI contrast agents. The invention also relates to a magnetic resonance sensor that alters it shape in response to a condition of an environment such that the condition may be detected.

A magnetic resonance contrast agent has a medium, and a contrast structure dispersed in the medium. The contrast structure comprises a magnetic material arranged to create a local region of a local magnetic field such that nuclear magnetic moments of a material when arranged within the local region precess at a characteristic Larmor frequency about a total magnetic field in the local region while in use, the characteristic Larmor frequency being identifiable with the contrast structure, and the total magnetic field in the local region being a substantially spatially uniform magnetic field.

Arrays of spin-valve elements that can be selectively activated to trap, hold, manipulate and release magnetically tagged biological and chemical particles, including molecules and polymers. The spin-valve elements that can be selectively activated and deactivated by applying a momentary applied magnetic field thereto. The spin valve element array can be used for selectively sorting and transporting magnetic particles one particle at a time within the array. As the magnetically tagged particles are held by the spin-valve elements, application of an auxiliary magnetic field can be used to apply tension or torsion to the held particles or to move, e.g. rotate, the trapped particles. The arrays of spin-valve elements can be used in a variety of applications including drug screening, nucleic acid sequencing, structural control and analysis of RNA/DNA and proteins, medical diagnosis, and magnetic particle susceptibility and size homogenization for other medical applications.

Microfluidic platform of arrayed switchable spin-valve elements for high-throughput sorting and manipulation of magnetic particles and biomolecules

Arrays of spin-valve elements that can be selectively activated to trap, hold, manipulate and release magnetically tagged biological and chemical particles, including molecules and polymers. The spin-valve elements that can be selectively activated and deactivated by applying a momentary applied magnetic field thereto. The spin valve element array can be used for selectively sorting and transporting magnetic particles one particle at a time within the array. As the magnetically tagged particles are held by the spin-valve elements, application of an auxiliary magnetic field can be used to apply tension or torsion to the held particles or to move, e.g. rotate, the trapped particles. The arrays of spin-valve elements can be used in a variety of applications including drug screening, nucleic acid sequencing, structural control and analysis of RNA/DNA and protiens, medical diagnosis, and magnetic particle susceptibility and size homogenization for other medical applications.

This invention relates principally to methods and apparatus for recording data on and reading data from a magnetizable medium using a scanning tunneling technique. Conventional rigid probes used in scanning tunneling microscopy (STM) and the like are replaced by a compliant magnetic probe wherein the STM image is a convolution of magnetic forces and the surface topography of the magnetizable medium. Data can be written to the medium by increasing the tunneling current, reducing the scan rate, and/or increasing the magnetization of the compliant magnetic tunneling tip in order to alter the local magnetic characteristics of the medium. A preferred material for the compliant probe is a free-standing thin film of iron vacuum-deposited on a glass substrate and later removed therefrom. The compliant probe of the invention may also be employed for imaging the local surface magnetization of a magnetic member.

Tunneling-stabilized magnetic reading and recording

A method for thermal environment sensing utilizing superconducting materi finds utility in the production of low power cryogenic flow meters, bolometers, level detectors and other types of thermal environment sensors. A device for determining the first and second derivatives (dV/dI and d.sup.2 V/dI.sup.2) utilizes a ramped current until a set value of the first derivative (dV/dI) is achieved, the current supply being placed in a feedback mode to maintain the first derivative constant and monitoring any changes in the second derivative (d.sup.2 V/dI.sup.2) which indicate changes in the thermal environment. Alternatively, the second derivative is maintained constant and the first derivative is measured. Any parameter which is indicative of the non-linearity of the relationship between the voltage and the current can be utilized instead of the second derivative.

Thermal properties measurement using a superconductor sensor

A highly sensitive force detector using a tunneling junction as a strain gauge is disclosed. The tunneling junction is connected to a deflection member which receives the force to be measured. The junction is connected in a nulling circuit to a magnetic flux motor which generates a restoring force precisely equal to the force to be measured. The magnetic flux required by the flux motor to do so is measured by a SQUID, the output of which is directly proportional to the flux to be measured. The device has applications in pressure sensing, weighing, gravity measurements, detection of massive objects, and elsewhere.

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Louisville, CO, United States of America

John M Moreland