8401 results about "Electromagnetic field" patented technology

Apparatus for tracking an object includes a plurality of field generators, which generate electromagnetic fields at different, respective frequencies in a vicinity of the object, and a radio frequency (RF) driver, which radiates a RF driving field toward the object. A wireless transponder is fixed to the object. The transponder includes at least one sensor coil, in which a signal current flows responsive to the electromagnetic fields, and a power coil, which receives the RF driving field and conveys electrical energy from the driving field to power the transponder. The power coil also transmits an output signal responsive to the signal current to a signal receiver, which processes the signal to determine coordinates of the object.

An arrangement is provided for charging a charge storage device by placing the charge storage device in an RF or microwave radiation field. One or more antennas which receive the radiated RF electromagnetic field are placed on the charge storage device. Rectifiers connected to the antennas rectify the received RF electromagnetic field an produce a DC output current which is used to charge the charge storage device. The charge storage device may be a battery or a capacitor and may form an integral part of an electronic device. The same RF field that charges the charge storage device can also be employed to communicate data to transponders which may be associated with computing devices.

A system and method for transferring power does not require direct electrical conductive contacts. There is provided a primary unit having a power supply and a substantially laminar surface having at least one conductor that generates an electromagnetic field when a current flows therethrough and having an active area defined within a perimeter of the surface, the at least one conductor being arranged such that electromagnetic field lines generated by the at least one conductor are substantially parallel to the plane of the surface within the active area; and at least one secondary device including at least one conductor that may be wound about a core; wherein the active area has a perimeter large enough to surround the conductor or core of the at least one secondary device in any orientation thereof substantially parallel to the surface of the primary unit in the active area, such that when the at least one secondary device is placed on or in proximity to the active area in a predetermined orientation, the electromagnetic field induces a current in the at least one conductor of the at least one secondary device.

A method and apparatus for determining the position and orientation of a remote object relative to a reference coordinate frame includes a plurality of field-generating elements for generating electromagnetic fields, a drive for applying, to the generating elements, signals that generate a plurality of electromagnetic fields that are distinguishable from one another, a remote sensor having one or more field-sensing elements for sensing the fields generated and a processor for processing the outputs of the sensing element(s) into remote object position and orientation relative to the generating element reference coordinate frame. The position and orientation solution is based on the exact formulation of the magnetic field coupling as opposed to approximations used elsewhere. The system can be used for locating the end of a catheter or endoscope, digitizing objects for computer databases, virtual reality and motion tracking. The methods presented here can also be applied to other magnetic tracking technologies as a final "polishing" stage to improve the accuracy of their P&O solution.

A method and apparatus for charging energy supplies in an unmanned aerial vehicle (UAV). The present invention relates to a UAV that comprises an inductive charging device that utilizes the electromagnetic field emanated by overhead/utility power lines, to charge the energy supplies. The UAV also includes a releasable latch for holding power lines to allow for the perching of the UAV on power lines during the charging process. The latch and the inductive charging device may be provided on a single device, a battery augmentation trap (BAT). The UAV may be perched in an upright orientation to allow for takeoff after the charging of energy supplies on the power line.

A first shielding box is disposed so that its first surface can be opposite to an electric power feeding unit. The first surface has an opening and remaining five surfaces thereof reflect, during reception of electric power from the electric power feeding unit, a resonant electromagnetic field (near field) generated in the surroundings of the electric power receiving unit. The electric power receiving unit is provided in the first shielding box to receive the electric power from the electric power feeding unit via the opening (first surface) of the first shielding box. A second shielding box has a similar configuration, i.e., has a second surface with an opening and remaining five surfaces thereof reflect the resonant electromagnetic field (near field) generated in the surroundings of the electric power feeding unit.

An electrical lead includes an elongate body having a proximal end portion and a distal end portion, a first electrode disposed adjacent and joined to the distal end portion of the elongate body. Current flow within the first electrode is limited when a predetermined condition occurs, such as the generation of an electromagnetic field having a predetermined frequency range. The medical electrical lead may further comprise one or more second electrodes disposed adjacent the first electrode and joined to the elongate body to shunt current to body tissue when the predetermined condition occurs.

A feedthrough terminal assembly for an active implantable medical device (AIMD) includes a plurality of leadwires extending from electronic circuitry of the AIMD, and a lossy ferrite inductor through which the leadwires extend in non-conductive relation for increasing the impedance of the leadwires at selected RF frequencies and reducing magnetic flux core saturation of the lossy ferrite inductor through phase cancellation of signals carried by the leadwires. A process is also provided for filtering electromagnetic interference (EMI) in an implanted leadwire extending from an AIMD into body fluids or tissue, wherein the leadwire is subjected to occasional high-power electromagnetic fields such as those produced by medical diagnostic equipment including magnetic resonance imaging.

A non-contact power charging system includes a wireless power transmission apparatus 10 for transmitting a power signal from a primary core 14 via a resonant converter 13 by the control of a transmission control unit 12; and a wireless power receiving apparatus 20 for receiving the power signal transmitted from the primary core 14 of the wireless power transmission apparatus 10 via a secondary core 24 and charging a battery cell 21 by the control of a receiving control unit 22. The wireless power receiving apparatus 20 includes a receiving shield panel 25 and an eddy current reducing member 26 in the side of the secondary core 24 to shield an electromagnetic field generated from the secondary core 24, to thereby protect the charging system and the battery pack from the electromagnetic field.

Provided is a wireless transmitter-receiver capable of suppressing undesirable power consumption and elongating the continuous operation time by operation of a user with the intention of controlling transmission power and also suitable to secure the “symmetry of communication”.

The wireless transmitter-receiver decreases the upper limit value of transmission power by an operation of an operation means 114 and decreases the reception sensitivity in accordance with the decreased upper limit value of transmission power. Thereby, a user can determine the upper limit value of transmission power of the wireless transmitter-receiver and manage the transmission power to suppress power consumption and elongate a continuous operation time. Moreover, the wireless transmitter-receiver can eliminate the influence of radio frequency electromagnetic field on a human body. Furthermore, the degree of imbalance in the “symmetry of communication” can be minimized.

Resonance can be surely provided under any plasma condition in such a manner that an antenna (3) is arranged in an opening of an upper part of a chamber (1) to produce an electromagnetic field generated by a microwave, a top plate (4) for sealing the opening of the chamber (1) is provided under the antenna (3), a ring-shaped ridge (41) is provided on a lower surface of the top plate (4) such that a thickness thereof in a diameter direction is tapered so as to be varied sequentially. Thus, only one kind of top plate has the same effect as a top plate having various thicknesses, so that absorption efficiency to the plasma can be considerably improved and the plasma can be generated stably over a range from a high pressure to a low pressure.

Floating electromagnetic field generator systems and methods are provided. The system comprises a surgical bed portion. The system also comprises a brace component disposed within the surgical bed portion. Additionally, the system comprises a first arm that is attached to the brace component. The first arm is positioned adjacent to the surgical bed portion. Additionally, the first arm has at least one field generator coil embedded therein. The system also comprises a second arm that is attached to the brace component. The second arm is positioned adjacent to the surgical bed portion. Additionally, the second arm has at least one field generator coil embedded therein. The second arm is positioned parallel to the first arm.

A method and an apparatus for trapping induced current resulting from an electromagnetic field. Embodiments of the present invention provide for an elongate body having a proximal and a distal end portion and a coil wound about the distal end, the coil to provide an electromagnetic trap for filtering radio frequency (RF) signal-induced currents.

An inductive power transfer system (1) comprises a primary unit (10) operable to generate an electromagnetic field and at least one secondary device (30), separable from the primary unit, and adapted to couple with the field when the secondary device is in proximity to the primary unit so that power can be received inductively by the secondary device from the primary unit without direct electrical conductive contacts therebetween. The system detects if there is a substantial difference between, on the one hand, a power drawn from the primary unit and, on the other hand, a power required by the secondary device or, if there is more than one secondary device, a combined power required by the secondary devices. Following such detection, the system restricts or stops the inductive power supply from the primary unit. Such a system can detect the presence of unwanted parasitic loads in the vicinity of the primary unit reliably.

A search system for a tool. A border cable separates inner and outer areas. A generator feeds the border cable with current, whose magnetic field affects a sensing unit on the tool, and the sensing unit emits signals to a control unit that directs the tool's motion. The current contains at least two components of different frequency. A search cable is placed within the inner area so that it separates a search area, and is fed by a signal generator with an adapted current (e.g., the current direction alternates to be either in phase or out of phase in relation to the current direction in the border cable) so that the magnetic fields in the different areas provide at least three patterns. Accordingly, the control unit can separate the inner, outer, and search areas.

A medical electrical lead is disclosed comprising an electrically-conductive shield adjacent to at least a portion of the lead body. The shield is adapted to dissipate energy when the lead is subjected to an electromagnetic field. The shield may be further coupled to a housing of an implantable medical device to enhance energy dissipation capabilities. In another embodiment, a method comprises receiving electromagnetic energy within a shield coating surrounding a portion of the lead. The energy is then dissipated in a manner that protects tissue surrounding the lead from injury.