Abstract: A method for obtaining full tensor gain compensated propagation measurements includes processing a full tensor voltage measurement to obtain a fully gain compensated tensor quantity. An electromagnetic logging tool including at least first and second axially spaced transmitters and at least first and second axially spaced receivers is rotated in a subterranean borehole. A plurality of voltage measurements are acquired while rotating to obtain a full tensor voltage measurement which is in turn processed to obtain the fully gain compensated tensor quantity.

Abstract: A method for obtaining gain corrected triaxial electromagnetic propagation measurements with an offset correction includes deploying an electromagnetic logging tool in a subterranean borehole. The logging tool includes at least first and second axially spaced triaxial transmitters and at least first and second axially spaced triaxial receivers. A plurality of full tensor voltage measurements may be acquired and processed tensor term by tensor term to obtain a full tensor, gain corrected quantity. The processing may optionally include (i) removing a full tensor voltage offset from the acquired full tensor voltage measurements to obtain a corresponding plurality of offset corrected voltage tensors and (ii) processing the offset corrected voltage tensor term by tensor term to obtain the full tensor, gain and offset corrected quantity.

Abstract: A shoe insert includes a generally planar body having a perimeter defining a foot-shaped area on an upper side of the body, the foot-shaped area including first and second toe areas and a heel area configured respectively for placement of a first toe, a second toe, and a heel of a user. The upper side defines a channel extending along an axis passing through a space between the first and second toe areas and the heel area. A linear member may be placed in the channel to protrude from an upper surface of the body. When a user uses the insert, the user's foot may sense the channel (or linear member, if present) and activate mechano-receptors on the bottom of the foot along the channel, which, in-turn, may train the foot to extend in a predetermined position relative to the linear member to improve balance.

Abstract: A method for making downhole electromagnetic logging while drilling measurements includes rotating an electromagnetic logging while drilling tool in a subterranean wellbore. The logging tool includes a first transmitter and a first receiver deployed on a first sub and a second transmitter and a second receiver deployed on a second sub. Rotating the logging tool causes the first and second subs to rotate at different rates. A plurality of electromagnetic voltage measurements are acquired from the first and second receivers while rotating. The acquired voltage measurements are processed to compute harmonic coefficients which are mathematically rotated to obtain rotated coefficients. Ratios of selected ones of the rotated coefficients are processed to compute gain compensated measurement quantities.

Abstract: The system, device, and method may use electrical stimulation of the vagus nerve to treat epilepsy with minimized or no effect on the heart. Treatment is carried out by an implantable signal generator, one or more implantable electrodes for electrically stimulating a predetermined stimulation site of the vagus nerve, and a sensor for sensing characteristics of the heart such as heart rate. The heart rate information from the sensor can be used to determine whether the vagus nerve stimulation is adversely affecting the heart. Once threshold parameters are met, the vagus nerve stimulation may be stopped or adjusted. In yet another embodiment, the system, device, and method may be simply a modified pacemaker having circuitry that determines whether a vagus nerve is being stimulated. In the event that the vagus nerve is being stimulated, the modified pacemaker may control the heart to maintain it within desired conditions during the vagus nerve stimulation.

Abstract: A method for obtaining fully gain compensated propagation measurements includes rotating an electromagnetic logging while drilling tool in a subterranean wellbore. The tool includes first and second transmitters and first and second receivers axially spaced apart from one another in which each of the transmitters and each of the receivers include an axial antenna and collocated first and second transverse antennas. The first and second transverse antennas in the first receiver are rotationally offset by a predefined angle from the first and second transverse antennas in the first transmitter. A plurality of electromagnetic voltage measurements are acquired at the first and second receivers while rotating and processed to compute harmonic coefficients. The harmonic coefficients are mathematically rotated through at least the predefined angle to obtain rotated coefficients. Ratios of selected ones of the rotated coefficients are processed to compute fully gain compensated measurement quantities.

Abstract: A deep reading electromagnetic logging while drilling tool includes first and second logging while drilling subs, the first of which includes a first transmitter and a first receiver axially spaced apart from one another and the second of which includes a second transmitter and a second receiver axially spaced apart from one another. Each of the first and second transmitters and first and second receivers includes an axial antenna and collocated first and second transverse antennas. The first and second transverse antennas in the first receiver are rotationally offset by a predefined angle from the first and second transverse antennas in the first transmitter.

Abstract: A method for obtaining gain compensated electromagnetic logging while drilling propagation measurements includes rotating an electromagnetic logging while drilling tool having first and second transverse transmitter antennas whose moments are orthogonal to one another and first and second transverse receiver antennas whose moments are orthogonal to one another in a subterranean wellbore. Electromagnetic voltage measurements are acquired from the first and second transverse receiver antennas while rotating. The acquired voltage measurements are processed to compute harmonic voltage coefficients. Ratios of selected ones of the harmonic voltage coefficients are in turn processed to compute a gain compensated quantity including a transverse term.

Abstract: A method for obtaining gain compensated propagation measurements includes rotating an electromagnetic logging while drilling tool having at least one axial transmitter antenna, at least one transverse transmitter antenna, at least one axial receiver antenna and at least one transverse receiver antenna in a subterranean wellbore. Electromagnetic voltage measurements are acquired from the axial and transverse receiver antennas while rotating. The acquired voltage measurements are processed to compute harmonic voltage coefficients. Ratios of selected ones of the harmonic voltage coefficients are in turn processed to compute at least one gain compensated quantity including an axial cross term.

Abstract: A method for obtaining full tensor gain compensated propagation measurements includes processing a full tensor voltage measurement to obtain a fully gain compensated tensor quantity. An electromagnetic logging tool including at least first and second axially spaced transmitters and at least first and second axially spaced receivers is rotated in a subterranean borehole. A plurality of voltage measurements are acquired while rotating to obtain a full tensor voltage measurement which is in turn processed to obtain the fully gain compensated tensor quantity.

Abstract: A method for obtaining full tensor gain compensated propagation measurements includes processing a full tensor voltage measurement to obtain a fully gain compensated tensor quantity. An electromagnetic logging tool including at least first and second axially spaced transmitters and at least first and second axially spaced receivers is rotated in a subterranean borehole. A plurality of voltage measurements are acquired while rotating to obtain a full tensor voltage measurement which is in turn processed to obtain the fully gain compensated tensor quantity.

Abstract: A method for making downhole electromagnetic logging while drilling measurements includes rotating an electromagnetic logging while drilling tool in a subterranean wellbore. The logging tool includes a first transmitter and a first receiver deployed on a first sub and a second transmitter and a second receiver deployed on a second sub. Rotating the logging tool causes the first and second subs to rotate at different rates. A plurality of electromagnetic voltage measurements are acquired from the first and second receivers while rotating. The acquired voltage measurements are processed to compute harmonic coefficients which are mathematically rotated to obtain rotated coefficients. Ratios of selected ones of the rotated coefficients are processed to compute gain compensated measurement quantities.

Abstract: A method for obtaining gain compensated electromagnetic logging while drilling propagation measurements includes rotating an electromagnetic logging while drilling tool in a subterranean wellbore. The tool includes a plurality of transmitter antennas and a plurality of receiver antennas symmetrically spaced along a logging while drilling tool body with the transmitter antennas including at least one axial transmitter antenna and at least one transverse transmitter antenna and the receiver antennas including at least one axial receiver antenna and at least one transverse receiver antenna. Electromagnetic voltage measurements are acquired from the receiver antennas while rotating. The acquired voltage measurements are processed to compute harmonic voltage coefficients. Ratios of selected ones of the harmonic voltage coefficients are in turn processed to compute gain compensated quantities including symmetrized and anti-symmetrized quantities.

Abstract: A deep reading electromagnetic logging while drilling tool includes first and second logging while drilling subs, the first of which includes a first transmitter and a first receiver axially spaced apart from one another and the second of which includes a second transmitter and a second receiver axially spaced apart from one another. Each of the first and second transmitters and first and second receivers includes an axial antenna and collocated first and second transverse antennas. The first and second transverse antennas in the first receiver are rotationally offset by a predefined angle from the first and second transverse antennas in the first transmitter.

Abstract: A method for obtaining gain compensated electromagnetic logging while drilling propagation measurements includes rotating an electromagnetic logging while drilling tool having first and second transverse transmitter antennas whose moments are orthogonal to one another and first and second transverse receiver antennas whose moments are orthogonal to one another in a subterranean wellbore. Electromagnetic voltage measurements are acquired from the first and second transverse receiver antennas while rotating. The acquired voltage measurements are processed to compute harmonic voltage coefficients. Ratios of selected ones of the harmonic voltage coefficients are in turn processed to compute a gain compensated quantity including a transverse term.

Abstract: A method for obtaining gain compensated propagation measurements includes rotating an electromagnetic logging while drilling tool having at least one axial transmitter antenna, at least one transverse transmitter antenna, at least one axial receiver antenna and at least one transverse receiver antenna in a subterranean wellbore. Electromagnetic voltage measurements are acquired from the axial and transverse receiver antennas while rotating. The acquired voltage measurements are processed to compute harmonic voltage coefficients. Ratios of selected ones of the harmonic voltage coefficients are in turn processed to compute at least one gain compensated quantity including an axial cross term.

Abstract: A method for obtaining fully gain compensated propagation measurements includes rotating an electromagnetic logging while drilling tool in a subterranean wellbore. The tool includes first and second transmitters and first and second receivers axially spaced apart from one another in which each of the transmitters and each of the receivers include an axial antenna and collocated first and second transverse antennas. The first and second transverse antennas in the first receiver are rotationally offset by a predefined angle from the first and second transverse antennas in the first transmitter. A plurality of electromagnetic voltage measurements are acquired at the first and second receivers while rotating and processed to compute harmonic coefficients. The harmonic coefficients are mathematically rotated through at least the predefined angle to obtain rotated coefficients. Ratios of selected ones of the rotated coefficients are processed to compute fully gain compensated measurement quantities.

Abstract: An improved protective helmet having an outer impact receiving shell, and inner protective shell and an intermediate piston interposed between the outer and inner shells which allows the inner shell to decelerate gradually when the outer shell is subjected to a sudden impact, and which, therefore, permits the brain to decelerate safely.

Abstract: The present invention uses electrical stimulation of the vagus nerve to treat epilepsy with minimized or no effect on the heart. Treatment is carried out by an implantable signal generator, one or more implantable electrodes for electrically stimulating a predetermined stimulation site of the vagus nerve, and a sensor for sensing characteristics of the heart such as heart rate. The heart rate information from the sensor can be used to determine whether the vagus nerve stimulation is adversely affecting the heart. Once threshold parameters are met, the vagus nerve stimulation may be stopped or adjusted. In yet another embodiment, the invention may be simply a modified pacemaker having circuitry that determines whether a vagus nerve is being stimulated. In the event that the vagus nerve is being stimulated, the modified pacemaker may control the heart to maintain it within desired conditions during the vagus nerve stimulation.

Abstract: A method for obtaining gain corrected triaxial electromagnetic propagation measurements with an offset correction includes deploying an electromagnetic logging tool in a subterranean borehole. The logging tool includes at least first and second axially spaced triaxial transmitters and at least first and second axially spaced triaxial receivers. A plurality of full tensor voltage measurements may be acquired and processed tensor term by tensor term to obtain a full tensor, gain corrected quantity. The processing may optionally include (i) removing a full tensor voltage offset from the acquired full tensor voltage measurements to obtain a corresponding plurality of offset corrected voltage tensors and (ii) processing the offset corrected voltage tensor term by tensor term to obtain the full tensor, gain and offset corrected quantity.