An implantable medical device (IMD) that includes a housing, a first electrode secured relative to the housing, a second electrode secured relative to the housing, and a gyroscope secured relative to the housing. The IMD may include circuitry in the housing in communication with the first electrode, the second electrode, and the gyroscope. The circuitry may be configured to determine and store a plurality of torsion data measurements, from which a representation of a twist profile may be determined.

A MEMS gyrocompass and method are provided to mitigate systematic error in determination of a north angle. The MEMS gyrocompass includes one or more MEMS gyroscopes having a sense axis within a reference plane. Samples from an output of the MEMS gyroscope are obtained in at least two angles of rotation about an axis perpendicular to the reference plane. First fit coefficients are determined by fitting samples with first fitting functions determined as function of time. Second fit coefficients are determined by fitting components of earth rotation rate projected on the reference plane based on samples obtained by all the MEMS gyroscopes, which fitting is performed with a second fitting function determined as a function of rotation angle of the MEMS gyroscope with respect to a reference angle. The north angle is determined as an angle between the reference angle and true north based on the second fit coefficients.

Various implementations directed to providing a continuous wellbore survey are provided. In one implementation, a method may include acquiring stationary survey data using a survey tool disposed at a stationary position within a wellbore, where the survey tool is configured to be deployed to the stationary position from a moving platform, and where the stationary position is lower than a predetermined depth within the wellbore. The method may also include acquiring continuous survey data during an outrun data acquisition using the survey tool, where the survey tool is configured to ascend within the wellbore during the outrun data acquisition. The method may further include transmitting the continuous survey data and the stationary survey data to a computing system, where the computing system is configured to generate a continuous survey of the wellbore based on the continuous survey data and the stationary survey data.

Various implementations directed to providing a continuous wellbore survey are provided. In one implementation, a method may include acquiring stationary survey data using a survey tool disposed at a stationary position within a wellbore, where the survey tool is configured to be deployed to the stationary position from a moving platform, and where the stationary position is lower than a predetermined depth within the wellbore. The method may also include acquiring continuous survey data during an outrun data acquisition using the survey tool, where the survey tool is configured to ascend within the wellbore during the outrun data acquisition. The method may further include transmitting the continuous survey data and the stationary survey data to a computing system, where the computing system is configured to generate a continuous survey of the wellbore based on the continuous survey data and the stationary survey data.

A generator system having a dynamo that contains an armature, a stator and a housing. The armature rotates about a first axis of rotation. The stator is concentrically positioned around the armature. Both the armature and the stator are free to rotate in opposite directions about the first axis of rotation. The housing of the dynamo is connected to a motor that can rotate the dynamo around a second axis of rotation. There is an angle of inclination between the first axis of rotation and the second axis of rotation. This angle of inclination is selectively altered during operation by arms that attach to torque converters. By changing the angle of inclination between the two axes of rotation, a precession can be created that adds rotational energy to both the armature and the stator. This increases the output of the dynamo and creates a highly efficient electrical generator.

A generator system having a dynamo that contains an armature, a stator and a housing. The armature rotates about a first axis of rotation. The stator is concentrically positioned around the armature. Both the armature and the stator are free to rotate in opposite directions about the first axis of rotation. The housing of the dynamo is connected to a motor that can rotate the dynamo around a second axis of rotation. There is an angle of inclination between the first axis of rotation and the second axis of rotation. This angle of inclination is selectively altered during operation by arms that attach to torque converters. By changing the angle of inclination between the two axes of rotation, a precession can be created that adds rotational energy to both the armature and the stator. This increases the output of the dynamo and creates a highly efficient electrical generator.

An implantable medical device (IMD) that includes a housing, a first electrode secured relative to the housing, a second electrode secured relative to the housing, and a gyroscope secured relative to the housing. The IMD may include circuitry in the housing in communication with the first electrode, the second electrode, and the gyroscope. The circuitry may be configured to determine and store a plurality of torsion data measurements, from which a representation of a twist profile may be determined.

An implantable medical device (IMD) that includes a housing, a first electrode secured relative to the housing, a second electrode secured relative to the housing, and a gyroscope secured relative to the housing. The IMD may include circuitry in the housing in communication with the first electrode, the second electrode, and the gyroscope. The circuitry may be configured to determine and store a plurality of torsion data measurements, from which a representation of a twist profile may be determined.

Systems and methods for providing automatic detection of inertial sensor deployment environments are provided. In one embodiment, an environment detection system for a device having an inertial measurement unit that outputs a sequence of angular rate measurements comprises: an algorithm selector; and a plurality of environment detection paths each receiving the sequence of angular rate measurements, and each generating angular oscillation predictions using an environment model optimized for a specific operating environment. The environment model for each of the environment detection paths is optimized for a different operating environment. Each of the environment detection paths outputs a weighting factor that is a function of a probability that its environment model is a true model of a current operating environment given the sequence of angular rate measurements; and wherein the algorithm selector generates an output based on a function of the weighting factor from each of the environment detection paths.

Systems and methods for providing automatic detection of inertial sensor deployment environments are provided. In one embodiment, an environment detection system for a device having an inertial measurement unit that outputs a sequence of angular rate measurements comprises: an algorithm selector; and a plurality of environment detection paths each receiving the sequence of angular rate measurements, and each generating angular oscillation predictions using an environment model optimized for a specific operating environment. The environment model for each of the environment detection paths is optimized for a different operating environment. Each of the environment detection paths outputs a weighting factor that is a function of a probability that its environment model is a true model of a current operating environment given the sequence of angular rate measurements; and wherein the algorithm selector generates an output based on a function of the weighting factor from each of the environment detection paths.