There is provided an ultrasonic inspection apparatus using scanning path information with high accuracy at a time of ultrasonic flaw inspection. The present invention also provides a process for preparing a modified hemoglobin molecule, comprising the steps of: reacting Hb with 8-15 fold excess of iminothiolane to form thiolated Hb; and reacting the thiolated Hb with 16-30 fold excess of PEG functionalized with a maleimide moiety, to form the modified Hb. The duration quantizer function also produces a feedback PCM value x from each quantized duration value d that is applied to a loop filter, the output of which modifies the received PCM sample stream to suppress quantization noise. A removable, programmable memory is provided for storing therein control and other format information for a particular electronic apparatus to be operated.