JPS6439527A - Transducer for heart function diagram - Google Patents

Abstract

PURPOSE:To enable stable displacement detection with good operability by detecting a relative distance between a magnetic field producing element and an amorphous ferromagnetic material thin belt varying through a sensing chip when the surface of the body is displaced. CONSTITUTION:This transducer is equipped with a small magnet 6 which is arranged on the upper wall surface 1a in a shield case 1 through a magnet installation base 21, the amorphous ferromagnetic material thin belt 2 arranged at an interval with the magnetic 6, a coil 3 for detection which uses the thin belt 2 as its magnetic core, a detecting circuit 4 which detects its self-inductance by supplying a fine AC current to the coil 3, a sensing chip 20 which is adhered to an end part 2a of the thin belt 2, etc. Then the lower end surface 20a of the chip 20 is brought into contact with a measurement position of the body surface 5 and when the surface 5 is displaced to displace the thin belt 2 through the chip 20 and then the distance (x) between the magnet 6 and thin belt 2 varies, a magnetic field applied to the coil 3 by the magnet 6 varies. That is transduced into variation in the self-inductance of the coil 3 and detected 4 to measure the displacement of the surface 5. Namely, the transducer operates with the fine current and a measurement is taken without any hysteresis loss.