206 results about "Source field" patented technology

An apparatus and method for locating a magnetic implant in a surgical application using the field of a source magnet for the implant guiding field. The source magnet is an electromagnet having a separate calibrated magnetic field component in addition to the guiding field, so that both the magnitude and orientation of the magnetic field as a function of position around the magnet are known. A magnetic implant is provided with a sensor, such as a three-axis Hall effect sensor, to provide an indication of the magnitude and orientation of an applied magnetic field when the implant is surgically implanted in a patient. After implantation, the source magnet is energized with a current having a modulated component. The modulated component is received and filtered from the signal received from the Hall effect sensor in the implant, and provided to a processor that computes the location of the implant relative to the electromagnet based upon the detected magnitude and orientation of the modulated component of the magnetic field, and the location and orientation of the electromagnet. Localizers may be used to supply the relative locations of the patient and the electromagnet to the processor. A display may be provided to display a representation of the location of the implant in the patient, which may also be superimposed over a preoperative image of the patient.

Methods are described for assessing material condition. These methods include the use of multiple source fields for interrogating and loading of a multicomponent test material. Source fields include electric, magnetic, thermal, and acoustic fields. The loading field preferentially changes the material properties of a component of the test material, which allows the properties of the component materials to be separated. Methods are also described for monitoring changes in material state using separate drive and sense electrodes with some of the electrodes positioned on a hidden or even embedded material surface. Statistical characterization of the material condition is performed with sensor arrays that provide multiple responses for the material condition during loading. The responses can be combined into a statistical population that permits tracking with respect to loading history. Methods are also described for measuring the stress in the material by independently estimating effective electrical properties, such as magnetic permeability or electrical conductivity, using layered models or predetermined spatial distributions with depth that are then correlated with the stress.

This invention discloses an improved trenched metal oxide semiconductor field effect transistor (MOSFET) device that includes a trenched gate surrounded by a source region encompassed in a body region above a drain region disposed on a bottom surface of a substrate. The MOSFET cell further includes a shielded gate trench (SGT) structure below and insulated from the trenched gate. The SGT structure is formed substantially as a round hole having a lateral expansion extended beyond the trench gate and covered by a dielectric linen layer filled with a trenched gate material. The round hole is formed by an isotropic etch at the bottom of the trenched gate and is insulated from the trenched gate by an oxide insulation layer. The round hole has a lateral expansion beyond the trench walls and the lateral expansion serves as a vertical alignment landmark for controlling the depth of the trenched gate. The MOSFET device has a reduced gate to drain capacitance Cgd depending on the controllable depth of the trenched gate disposed above the SGT structure formed as a round hole below the trenched gate.