Konica Minolta SONIMAGE HS2 - 1.3 Operating Principles

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This system transmits ultrasound signals into the human body from an ultrasound transducer and receives the re-
ected echoes from the human body using the same transducer. It then processes the received signals to display
them as images on a display screen (LCD monitor) and to generate Doppler sound from a speaker.
Gating signals are sent from the scan control circuit through the transmission delay circuit and are input to the trans-
mission circuit. The transmission circuit then generates the transmission signals (electrical pulses) according to the
gating signals.
These electrical pulses are applied to piezoelectric elements that convert the electrical signals into mechanical vibra-
tions in the transducer. When the ultrasound signals transmitted into the human body encounter a substance with
di󰀨erent acoustic characteristics, they are reected and return to the transducer as echoes. The transducer mechani-
cally vibrates due to ultrasonic vibration, converts the ultrasound signals to electrical signals through mechanical-
electrical conversion, processes these received signals, and displays them on the image display screen. Based on
the time required for the ultrasound signals to return to the transducer, the distance between the transducer surface
and the reecting substance can be determined.
This system supports linear, convex and sector scanning techniques.
In B-mode imaging, the echo amplitudes are represented as brightness changes on the image display screen. Since
the ultrasound beam attenuates in tissue, the degree of amplication required generally increases as depth increas-
es. Regions of high reection are displayed as brighter, while regions of low reection appear darker.
In color ow imaging, phase detection is performed in a receive signal processing circuit to obtain I and Q signals.
These signals undergo frequency analysis with the correlational method in a color ow imaging circuit to produce the
mean velocity, variance, and power information of the blood ow. These information items are assigned color signals
and represented as real-time two-dimensional color ow images.
In Doppler imaging, the signals output from the receive signal processing circuit are frequency-analyzed by fast
Fourier transform (FFT) in a Doppler circuit to produce velocity and power information. A Doppler image is then dis-
played, plotting velocity on the vertical axis, time on the horizontal axis, and representing power as brightness.
The basic measurements are possible, including distance, time, angle, and trace. Combinations of some basic mea-
surements are also possible.
1.3 Operating Principles