Simplified water-bag technique for magnetic susceptibility measurements on the human body and other specimens

摘要

A probe instrument using room temperature magnetic sensor(s) for noninasively measuring variations in magnetic susceptibilities with sufficient resolution to monitor paramagnetic materials in a human body, such as iron in liver. Tissue response to an alternating current field applied by an applied field coil is detected. Applied field coil dimensions are chosen for maximum response from the liver while minimizing effects from overlying abdominal tissue and at the same time not unduly increasing instrument sensitivity to the lung. To overcome variations in sensor output due to fluctuations in the applied field, change in ambient temperature and mechanical relaxation of the instrument, sensor sample distance is modulated. Detector assembly is oscillated while the patient remains stationary. An improved water-bag technique is employed to eliminate background tissue response. The detector assembly forms part of a probe instrument for noninvasively detecting the paramagnetic concentration of a patient.