Abstract: A method and apparatus to screen individuals specifically for paramagnetic or ferromagnetic objects they may be carrying or wearing, before they enter a controlled area. The device comprises a screening portal, including multiple sensor arrays and associated electronics. The device places the sensor arrays in close proximity to a subject's body, including the head and feet if desired, for screening purposes. The portal can have multiple excitation sources oriented to generate a multi-axis excitation field, and multi-axis sensors. The portal can also have an interlock with the door of the controlled area.

Abstract: A method and apparatus to screen individuals specifically for paramagnetic or ferromagnetic objects they may be carrying or wearing, before they enter a controlled area. The device comprises a screening portal, including at least one magnetic gradiometer and its electronics. The device places all of the sensor arrays in close proximity to a subject's body, for screening purposes. The portal has at least one excitation coil oriented to cause the excitation field to have zero mutual inductance with the gradiometers.

Abstract: A method and apparatus to screen individuals specifically for paramagnetic or ferromagnetic objects they may be carrying or wearing, before they enter the high-field region of an MRI suite. The device comprises either a screening portal or a compact, hand-held magnetic gradiometer and its electronics. The device places all of the sensor arrays in close proximity to all parts of a subject's body, for screening purposes.

Abstract: A method and apparatus to screen individuals specifically for paramagnetic or ferromagnetic objects they may be carrying or wearing, before they enter a security area. The device comprises either a screening portal or a compact, hand-held magnetic gradiometer and its electronics. The device places all of the sensor arrays in close proximity to all parts of a subject's body, for screening purposes.

Abstract: An apparatus for and a method of measuring material thickness with magnetics. The thickness monitoring system includes a thickness monitor, a probe, and a target. In a preferred embodiment, the probe is positioned on one side of an article for which the thickness is to be determined. The target is positioned on the opposite side of the article from the probe. The probe includes an excitation coil, a field compensation coil, and a magnetic sensor. The method includes energizing the excitation coil to excite a response from the target, compensating for the effect of the excitation coil on the magnetic sensor, measuring the response of the target with the magnetic sensor, and determining the thickness of the article from the measured response. The preferred mode of energizing the excitation coil is with an AC waveform; however DC, multi-frequency AC, or a combination of AC and DC waveforms may be used.

Abstract: Methods and apparatus for minimizing the effects of temperature drift in a magnetic susceptibility measurement instrument, such as an instrument used in pre-MRI screening for the presence of ferromagnetic foreign bodies. The magnetic field source and magnetic sensors can be combined into a single, rigid unit. The stability and sensitivity required in high quality magnetic susceptibility measurements can be achieved through symmetrical design of the source-sensor unit, minimization of thermal stresses, minimization of temperature variations, use of materials with low thermal expansion coefficients, or through appropriate combinations thereof. Use of patient eye movement where an eye is being screened, use of a water bag between the patient and the instrument, or use of telemedicine to facilitate performance of the necessary computations can also be incorporated.

Abstract: A probe instrument using room-temperature sensor(s) that can measure magnetic susceptibilities variations. The instrument includes room temperature magnetic sensors, and detects the sample, that is the tissue response to an applied field coil. The sensors that can be used include magnetoresistive, fluxgate and magnetoinductive sensors. The applied field coil dimensions are chosen so that the applied field is optimized for maximum response from the item of interest while minimizing the effects due to the overlying tissue and at the same time not unduly increasing the sensitivity of the instrument to adjacent organs. To minimize noise introduced in the sensor due to fluctuations in the applied field, the applied field is canceled at the position of the sensor. To overcome variations in the sensor output due to fluctuations in the applied field, change in the ambient temperature and mechanical relaxation of the instrument, the detector assembly is oscillated while the examined patient remains stationary.

Abstract: A probe instrument using room-temperature sensor(s) that can measure variations in magnetic susceptibilities. The instrument has sufficient resolution to monitor paramagnetic materials in a human body, such as iron in a human liver, by noninvasively examining patients with iron-overload diseases. The instrument includes room temperature magnetic sensors, and detects the sample, that is, the tissue response to an alternating current field applied by an applied field coil. The applied field coil dimensions are chosen so that the applied field is optimized for maximum response from the liver while minimizing the effects due to the overlying abdominal tissue and at the same time not unduly increasing the sensitivity of the instrument to the lung. To overcome variations in the sensor output due to fluctuations in the applied field, change in the ambient temperature and mechanical relaxation of the instrument, the sensor-sample distance is modulated.

Abstract: A probe instrument using room-temperature sensor(s) that can measure magnetic susceptibilities variations. The instrument includes room temperature magnetic sensors, and detects the sample, that is the tissue response to an applied field coil. The sensors that can be used include magnetoresistive, fluxgate and magnetoinductive sensors. The applied field coil dimensions are chosen so that the applied field is optimized for maximum response from the item of interest while minimizing the effects due to the overlying tissue and at the same time not unduly increasing the sensitivity of the instrument to adjacent organs. To minimize noise introduced in the sensor due to fluctuations in the applied field, the applied field is canceled at the position of the sensor. To overcome variations in the sensor output due to fluctuations in the applied field, change in the ambient temperature and mechanical relaxation of the instrument, the detector assembly is oscillated while the examined patient remains stationary.

Abstract: A probe instrument using room-temperature sensor(s) that can measure magnetic susceptibilities variations. The instrument has sufficient resolution to monitor paramagnetic materials in a human body, and preferably iron in a human liver by noninvasively examining patients with iron-overload diseases. The instrument includes room temperature magnetic sensors, and detects the sample, that is the tissue response to an alternating current field applied by an applied field coil. The sensors that can be used include magnetoresistive, fluxgate and magnetoinductive sensors. The applied field coil dimensions are chosen so that the applied field is optimized for maximum response from the liver while minimizing the effects due to the overlying abdominal tissue and at the same time not unduly increasing the sensitivity of the instrument to the lung. To minimize noise introduced in the sensor due to fluctuations in the applied field, the applied field is canceled at the position of the sensor, i.e.