Processes and apparatus for the investigation of internal physiological phenomena based on measurements of the impedance variation of the surface of the body

Claim 3

The method of claim 1 further including differentiating the measured component to obtain the impedance or resistivity.

Claim 4

The method of claim 1 wherein the electromagnetic field is applied using a magnetic dipole formed by a search coil through which a current of a given frequency w/2 pi flows, and wherein the plane of the search coil is perpendicular to the portion of the body to be examined and wherein the calculation of the values of the impedance function is effected by the measurement of the amplitude of the electrical component E contained in the plane of the emitter coil and by the measurement of the amplitude of the magnetic component H perpendicular to this plane on the surface of the skin at right angles to the coil or in its immediate vicinity, the value of the function being equal to E/H or to

Claim 5

The method of claim 3 wherein the depth of investigation in the resistivity medium

Claim 6

The method of claim 1, wherein the electromagnetic field is applied using a magnetic dipole comprising a search coil fed by a current of predetermined frequency, the coil resting on the surface of the body to be examined wherein the axis of a pick-up for measuring the magnetic field and the straight line joining the points for the application of electrodes for measuring the electrical field are perpendicular to the axis of the source, and located externally of the search coil wherein the pick-ups are arranged to measure the amplitude of the radial magnetic component Hx relative to the emitter search coil and the amplitude of the transverse electrical component Ey, and in that the value of the function

Claim 7

The method of claim 1, wherein the amplitude of the field components Ex and Hz of the electromagnetic field, perpendicular to the skin, are measured and the value of the function

Claim 8

The method of claim 1 wherein the magnetic field is applied using a dipole formed by a search coil, through which the strong current I flows, the dipole being in contact with the skin, and wherein the amplitude of the magnetic field Hz is measured by means of a pick-up formed by a coil having the same axis as the search coil and wherein the values of the mutual impedance function Z/Zo H/Hz (2a/I) are determined in which Zo is the mutual impedance in a vacuum.

Claim 9

The method of claim 5 wherein the value of the function Rho a Hz (a3 o w/3 I) is determined.

Claim 10

The method of claim 5, wherein the Values of any one of the functions:

Claim 11

The method of claim 1, wherein the amplitude of the Hx field is measured by using a pick-up coaxial with a search coil of the dipole located near the skin for applying the electromagnetic field, the plane of the search coil being perpendicular to the surface of the skin and wherein the value of Z/Zo Hx/Ho is determined.

Claim 12

The method of claim 1, wherein the phase shift of the various components relative to the emission current is measured.

Claim 13

The method of claim 1, wherein the measured electromagnetic field components are in phase and 90* out of phase with respect to the emission current.

Claim 14

The method of claim 1 wherein the measured component of the electromagnetic field is an impedance function which is used to obtain the impedance or resistivity of the body.

Claim 15

The method of claim 1 further including taking the second derivative of the measured component to obtain the impedance or resistivity.