A photoacoustic diagnostic apparatus having: a light source; a probe which receives an acoustic wave generated when light is irradiated onto an object from a light source and which converts the acoustic wave into an electrical signal; a memory unit which records the electrical signal; and a memory control unit which controls whether or not to cause the memory unit to record the electrical signal, wherein the memory control unit controls the memory unit on the basis of a timing at which the probe receives an acoustic wave generated from a portion other than a light absorbing material inside an object.

Photoacoustic diagnostic apparatus

PURPOSE:To detect the flaw of an extremely thin sample, etc., by providing a peak detector composed of an RF delay circuit, an adding circuit, a comparing circuit, etc. CONSTITUTION:When the level of an ultrasonic pulse from a probe exceeds a threshold value, a sequence starts and an RF signal separated into a compo nent inputted to an adding circuit 23 through an input circuit 9, and a compo nent which is inputted to the RF delay circuit 22 and delayed by the set time and then inputted to the circuit 23. Both signals are added by the circuit 23 and outputted to an RF detecting circuit 26. A comparing circuit 25, on the other hand, outputs a pulse with width corresponding to the addition signal from the circuit 23 when the arithmetic value of comparison between the delay RF signal and threshold value exceeds the threshold value. This pulse is outputted with pulse width corresponding to defective echo width right after a surface echo, so only the defective echo is gated as to the output signal of the circuit 23 which is inputted to the RF detecting circuit 26 as a gate pulse and the peak value of a detected signal is sampled by a peak value detecting circuit 20 at the same time, so that an output circuit 21 outputs a DC voltage proportional to the peak value as defective information.

Nonaka Toshio

Papers

Ultrasonic flaw detection device