385 results about "Magnetic gradient" patented technology

A process for determining the position of a moving object, by the following steps: scalar measurements are acquired by a set of sensors all installed on the same site, at a position known at each instant; the trajectory of the object is determined approximately by a model; the measurements output from each sensor are combined to obtain spatial gradient measurements representative of the vector electromagnetic disturbance of the moving object; a vector of parameters characteristic of the model is estimated as a function of gradient measurements and as a function of the position of the sensors; and the position of the object is determined as a function of the position of the sensors and the parameters vector.

A method for multi-slice magnetic resonance imaging, in which image data is acquired simultaneously from multiple slice locations using a radio frequency coil array, is provided. By way of example, a modified EPI pulse sequence is provided, and includes a series of magnetic gradient field “blips” that are applied along a slice-encoding direction contemporaneously with phase-encoding blips common to EPI sequences. The slice-encoding blips are designed such that phase accruals along the phase-encoding direction are substantially mitigated, while providing that signal information for each sequentially adjacent slice location is cumulatively shifted by a percentage of the imaging FOV. This percentage FOV shift in the image domain provides for more reliable separation of the aliased signal information using parallel image reconstruction methods such as SENSE. In addition, the mitigation of phase accruals in the phase-encoding direction provides for the substantial suppression of pixel tilt and blurring in the reconstructed images.

A magnetic delivery system for delivering a magnetizable particle to a location in a body, the device includes a magnetizable object implanted in the body, wherein the magnetizable object includes a plurality of segments distributed throughout the magnetizable object and wherein the segments are configured to provide a magnetic gradient for attracting the magnetizable particle and an external source of a magnetic field capable of (i) magnetizing the magnetizable particle and (ii) increasing a degree of magnetization of the magnetizable object and thereby creating the magnetic gradient. A drug delivery system including the magnetic delivery system and a magnetizable particle associated with a therapeutic agent and / or a cell. A cell delivery system based on the magnetic delivery system and a magnetizable particle associated with a cell. A method of using the magnetic delivery system for delivery of a therapeutic agent and / or a cell to a targeted location in a body.

An apparatus and method for carrying out the affinity separation of a target substance from a liquid test medium by mixing magnetic particles having surface immobilized ligand or receptor within the test medium to promote an affinity binding reaction between the ligand and the target substance. The test medium with the magnetic particles in a suitable container is removably mounted in an apparatus that creates a magnetic field gradient in the test medium. This magnetic gradient is used to induce the magnetic particles to move, thereby effecting mixing. The mixing is achieved either by movement of a magnet relative to a stationary container or movement of the container relative to a stationary magnet. In either case, the magnetic particles experience a continuous angular position change with the magnet. Concurrently with the relative angular movement between the magnet and the magnetic particles, the magnet is also moved along the length of the container causing the magnetic field gradient to sweep the entire length of the container. After the desired time, sufficient for the affinity reaction to occur, movement of the magnetic gradient is ended, whereby the magnetic particles are immobilized on the inside wall of the container nearest to the magnetic source. The remaining test medium is removed while the magnetic particles are retained on the wall of the container. The test medium or the particles may then be subjected to further processing.