| 摘要 |
<p>The electromagnetic signal is transmitted through the biological body. Either the detectors, preferably loops or coils, are placed so that the effect of the direct transmission cancels, and only that of the physiological modification is left. Alternatively, a secondary transmitter generates a compensating field at the detector again cancelling the effect of the primary transmission. Several ways of achieving this effect are possible, e.g., by orientating the axis of the detector element w.r.t. the primary field, or by using two detecting loops at right angles. Scanning with a rotating field, or with two frequencies simultaneously, are among the possibilities available.</p> |
