A method is provided for enhancing the transport of a selected ion having a predetermined charge-to-mass ratio through a biomolecular membrane located in a space subjected to a local magnetic field. The space defines at least one reference path passing through the membrane in opposite first and second directions. The method includes the steps of creating a magnetic field which, when combined with the local magnetic field, produces a magnetic field having a flux density with at least one component representable by a component vector having a direction extending in the first direction along the path. This component of the magnetic field has a magnitude that fluctuates at a predetermined rate to produce a nonzero average value. A predetermined relationship between the ratio of the selected rate to the nonzero average value and the charge-to-mass ratio of the predetermined ion is thereby created. The predetermined relationship, is a function of the cyclotron resonance frequency of the ion. The present invention also provides an apparatus for enhancing the transport of a selected ion having a predetermined charge-to-mass ratio through a biomolecular membrane. The apparatus includes field creating means responsive to signals for creating a magnetic field which, when combined with the local magnetic field, produces a magnetic field having a flux density with at least one component representable by a component vector having a direction extending along a path through the membrane and having a magnitude that fluctuates at a predetermined rate to create a nonzero average value. The ratio of the predetermined rate to the nonzero average value has a predetermined relationship with respect to the charge-to-mass ratio of the predetermined ion which is a function of the cyclotron resonance frequency of the ion. Signal generating means is provided for generating the signals, at least some of which are generated at the predetermined rate.

An apparatus and method for non-invasively sensing physiological changes in the brain is disclosed. The apparatus and method uses an electromagnetic field to measure localized impedance changes in brain matter and fluid. Various spatial and temporal techniques are used to localize impedance changes in the brain. The apparatus and method has particular application in locating and providing time-trend measurements of the process of brain edema or the process of hydrocephalus.

A magnetic neural stimulator is disclosed for the stimulation of biological tissue. The stimulator includes an inductive stimulation coil, an energy storage capacitor, a firing device and a charging circuit. The energy storage capacitor is charged by the charging circuit to a voltage level which is greater than the voltage level supplied to the charging circuit. The energy storage capacitor is partially discharged into the stimulation coil thereby producing a magnetic pulse. The charging and discharging of the capacitor is continuously performed so as to produce a plurality of high frequency magnetic pulses. The stimulation coil and the energy storage capacitor operate in a resonant manner under a control circuit which performs timing and gating functions.

An apparatus and method for regulating the growth of living tissue are provided. The apparatus includes a deformable magnetic field generator and a magnetic field detector for producing a controlled, fluctuating, directionally oriented magnetic field parallel to a predetermined axis projecting through the target tissue. The deformable magnetic field generator includes a pair of field coils embedded in a flexible material which allows the field coils to be plastically deformed to fit the contour of a body region such as a patient's limb. The field detector samples the magnetic flux density along the predetermined access and provides a signal to a microprocessor which determines the average value of the flux density. The applied magnetic field is oscillated at predetermined frequencies to maintain a preselected ratio of frequency to average flux density. This ratio is maintained by adjusting the frequency of the fluctuating magnetic field and/or by adjusting the intensity of the applied magnetic field as the composite magnetic flux density changes in response to changes in the local magnetic field to which the target tissue is subjected. By maintaining these precise predetermined ratios of frequency to average magnetic flux density, growth characteristics of the target tissue are controlled.

An apparatus and method for regulating the growth of living tissue are provided. The apparatus includes a deformable magnetic field generator and a magnetic field detector for producing a controlled, fluctuating, directionally oriented magnetic field parallel to a predetermined axis projecting through the target tissue. The deformable magnetic field generator includes a pair of field coils embedded in a flexible material which allows the field coils to be plastically deformed to fit the contour of a body region such as a patient's limb. The field detector samples the magnetic flux density along the predetermined access and provides a signal to a microprocessor which determines the average value of the flux density. The applied magnetic field is oscillated at predetermined frequencies to maintain a preselected ratio of frequency to average flux density. This ratio is maintained by adjusting the frequency of the fluctuating magnetic field and/or by adjusting the intensity of the applied magnetic field as the composite magnetic flux density changes in response to changes in the local magnetic field to which the target tissue is subjected. By maintaining these precise determined ratios of frequency to average magnetic flux density, growth characteristics of the target tissue are controlled.