An integrated circuit includes a magnetic sensor and a magnetic field generating coil. A control circuit on the integrated circuit responds to an activation indication received by the integrated circuit to cause activation of generation of a first magnetic field by the magnetic field generating coil. The control circuit responds to a subsequent activation indication to generate a second magnetic field different from the first magnetic field. The first magnetic field may have a polarity opposite to a polarity of the second magnetic field. A communication interface may be used to communicate one or more indications associated with an expected magnetic field strength, such as coil resistance, and a measured magnetic field strength measured by the magnetic sensor. The magnetic field generating coil may be coaxial with the magnetic sensor and the magnetic field generating coil may have an inner diameter greater than a diameter of the magnetic sensor.

A probe (303; 403) for sensing a magnetic marker, comprising a first set of coils (313; 413), which comprises a first coil of a first coil type, e.g. a sense coil (305; 405), disposed between a first pair of coils of second coil type, e.g. drive coils (301a, 301b; 401a, 401b), that are connected in series, and a balancing element (317; 417) which is axially separated from the first set of coils (313; 413) along a length of the probe (303; 403). The balancing element (317; 417) is configured and arranged to generate a sense voltage that wholly offsets, partially offsets, or minimises, a sense voltage induced in the sense coil or coils (305; 405) of the first set of coils from the drive coils or coil (301a, 301b; 401a, 401b). Also disclosed is a detection system comprising a probe (303; 403), a magnetic field generator arranged to drive an alternating magnetic field through the drive coils (301a, 301b; 401a, 401b) of the first set of coils and the balancing element (317; 417), and at least one detector arranged to receive a signal indicative of a sense voltage.

Magnetic field detectors include a proof mass suspended by deformable arms similar to a three dimensional accelerometer. The magnetic field detectors further include magnetically sensitive material present on the proof mass and/or deformable arms to cause movement of the proof mass and/or deformable arms when in the presence of a magnetic field. This movement is converted to an electrical signal and that electrical signal is compared to a reference to determine if a magnetic field of interest is present. The magnetic field detector may be included within an implantable medical device, and when the magnetic field detector indicates that a magnetic field of an MRI scanner is present, the implantable medical device may switch to an MRI mode of operation. The device may also switch back to a normal mode of operation once the MRI scanner is no longer detected such as after a predefined amount of time.

A linear variable displacement transformer (LVDT) position sensor. The position sensor comprises a bobbin, a primary coil of wire wound on the bobbin, a first secondary coil wound in stepped layers on the bobbin, and a second secondary coil wound in stepped layers on the bobbin. The first secondary coil comprises a plurality of booster windings at an end of the first secondary coil. The second secondary coil comprises a plurality of booster windings at an end of the second secondary coil opposite the end of the first secondary coil booster windings. The stepped windings of the second secondary coil are complementary to the stepped windings of the first secondary coil.

A linear variable displacement transformer (LVDT) position sensor. The position sensor comprises a bobbin, a primary coil of wire wound on the bobbin, a first secondary coil wound in stepped layers on the bobbin, and a second secondary coil wound in stepped layers on the bobbin. The first secondary coil comprises a plurality of booster windings at an end of the first secondary coil. The second secondary coil comprises a plurality of booster windings at an end of the second secondary coil opposite the end of the first secondary coil booster windings. The stepped windings of the second secondary coil are complementary to the stepped windings of the first secondary coil.

The present invention relates to a vector sensor for measuring particle movement in a medium. The vector sensor comprises a magnetic body that is held at a certain distance from a magnetometer in such a way that the magnetic body can move in time with a passing particle movement, wherein the magnetometer is arranged to detect the oscillations in the magnetic field that the movements in the medium produce.

The present invention relates to a vector sensor for measuring particle movement in a medium. The vector sensor comprises a magnetic body that is held at a certain distance from a magnetometer in such a way that the magnetic body can move in time with a passing particle movement, wherein the magnetometer is arranged to detect the oscillations in the magnetic field that the movements in the medium produce.

Systems and methods for filtering a micro-electromechanical system sensor rate signal with error feedback are provided. In one example, a micro-electromechanical system sensor rate signal is provided. Next, a feedback signal from a feedback loop is subtracted from the micro-electromechanical system sensor rate signal to produce a first combined signal. The first combined signal is then filtered to produce a filtered rate output. The micro-electromechanical system sensor rate signal is then subtracted from the filtered rate output to produce an error signal, wherein the error signal is used in the feedback loop to generate a feedback signal for a future time step.

Systems and methods may provide for obtaining first sensor data associated with a gyroscope and obtaining second sensor data associated with a magnetometer. Additionally, the first sensor data, the second sensor data and an extended Kalman filter may be used to calibrate the magnetometer. In one example, a sampling rate of the magnetometer is increased before obtaining the second sensor data and the sampling rate of the magnetometer is decreased after calibration of the magnetometer.

Systems and methods may provide for obtaining first sensor data associated with a gyroscope and obtaining second sensor data associated with a magnetometer. Additionally, the first sensor data, the second sensor data and an extended Kalman filter may be used to calibrate the magnetometer. In one example, a sampling rate of the magnetometer is increased before obtaining the second sensor data and the sampling rate of the magnetometer is decreased after calibration of the magnetometer.