Abstract: A probe is provided which comprises a plurality of ultrasonic transducer elements, and is so arranged as to be capable of simultaneously transmitting and receiving ultrasonic beams of plural frequencies. Means is provided for changing the shapes of the effective acoustic field of the ultrasonic beams of each a predetermined number of frequencies by selectively operating the ultrasonic transducer elements or interchanging transducers. The shapes of the effective acoustic fields of the ultrasonic beams of the plural frequencies are made substantially coincident in accordance with the range of distance from the probe. Thereby, the measuring of the tissue or the like with coincident shaped beams of plural frequencies can be realized.

Abstract: An ultrasonic diagnostic system for observing the state within a measured object by transmitting ultrasonic waves to the interior of a measured object such as the human body and by receiving acoustic waves reflected from the object. The system employs plural probe units which contain electric-acoustic transducers and are mutually isolated. A transmitting circuit causes the plural probe units almost simultaneously to transmit ultrasonic waves having different characteristics. A receiving circuit contains filters for isolating and extracting acoustic signals having characteristics corresponding to those particular transmitted ultrasonic waves from the other acoustic signals received. This system thereby obtains an acoustic image corresponding to each scanning line, and by means of scanning the measured object with each of the probe units, a display of the object's movement is obtained with plural scanning lines.

Abstract: In an ultrasonic wave tomographic imaging system wherein an acoustic image in an object is focused on the ultrasonic wave receiving means by means of an ultrasonic wave lens in order to pick up an image of the desired tomographic plane in the object, the clearness of a tomographic plane image is much improved by a structure wherein the ultrasonic wave is not generated to unwanted regions other than the desired tomographic plane of the object by providing the ultrasonic wave generating means so that scanning occurs only as to the desired tomographic plane of the object, and a gate means is provided so that the ultrasonic wave receiving means can receive an acoustic image corresponding to the scanning in accordance with the scanning of the ultrasonic wave generating means.

Abstract: A measurement method and system for measuring characteristics of attenuation of domains in an object comprises transmitting ultrasonic waves into the object and receiving ultrasonic waves reflected from the object. The measured characteristics of attenuation of reflected waves is determined using signal intensities. A plurality of ultrasonic waves having different frequencies are transmitted either simultaneously or alternately to an object, and the reflected waves are received from the object. The signal intensities corresponding to the transmission frequencies among the reflected waves are stored and the signal intensity ratio is calculated. The signal intensity ratio indicates the attenuation characteristic. The attenuation coefficient can also be obtained using a time interval from the transmission time to the time of the reflected wave is received. The attenuation slope can be obtained from this attenuation coefficient and the frequency difference between transmitted ultrasonic waves.

Abstract: An ultrasonic imaging apparatus comprises transducers for transmitting ultrasonic waves and receiving acoustic. The apparatus also transmits ultrasonic waves of different frequencies simultaneously from a plurality of transducers.The frequency characteristics of the transducers are determined in a manner so as to produce the function of frequency filters. An electric filter is additionally provided for compensation. Thus, crosstalk is eliminated even when the frequency difference between the transmitting ultrasonic waves is kept small.

Abstract: An automatic message announcement system for trains in the railroad station premises, including a train tracking circuit which tracks the location of approaching train, a trains information memory which stores information concerning each train, an edition circuit which combines the train information read out from said train information memory and a series of message patterns which include portions to be completed and which edits the message patterns to produce a series of short messages arranged sequentially according of their priority order to the content, an announcement message selection circuit which determines up to which short message among those arranged sequentially according to said priority order should be announced, in accordance with the location of the train at the time the announcement starts, and an automatic announcement system which includes a voice memory containing addressable voice segments for annoucing the message determined above.

Abstract: An automatic message announcement system for announcing the approach, arrival, and departure of vehicles such as trains at a train station. An addressable voice memory is provided for storing sequences of voice segments which are read out upon receipt of announcement command input signals to form messages for announcing that a vehicle is approaching or has arrived or is departing, with specific information such as the vehicle's destination being included in the announcement by inserting the appropriate voice segments at the proper points in the sequence. The messages are composed in such a manner that the sequences of voice segments can be altered to form shorter, but still intelligible, messages if vehicles traffic is so heavy that one message is due for announcement before the previous announcement is completed.