Patent ID: 7115094

Claim:
An ultrasonic imaging apparatus comprising: (a) an ultrasonic probe comprising a piezoelectric material, an acoustic matching layer provided on an ultrasonic radiation side of the piezoelectric material, and backing material provided on a rear side of the piezoelectric material, wherein the concentration of magnetic molecules of a magnetic susceptibility of 0.1 or more contained in the piezoelectric material, the acoustic matching layer and the backing material is 3×10 −7 mol/cm 3 or less; (b) a transmit beam former controlling a transmit focal point of an ultrasonic wave inside the body of a subject; (c) a receive beam former controlling a receive focal point of an ultrasonic wave inside the body of the subject; (d) a transmit/receive switch which switches between connecting a transmit electric signal from the transmit beam former to the ultrasonic probe or connecting a receive electric signal from the ultrasonic probe to the receive beam former; and (e) a switch means located between the ultrasonic probe and the transmit/receive switch which, electrically disconnects the ultrasonic probe, including a ground wire, from the transmit/receive switch.