Delay data ROM:
The data stored in this ROM is output according to the data given by the Focus calculator.
Gate Array:
This generates the transmission trigger based on the delay data and number of transmission pulses for each channel based on the data from the Delay Data ROM.
Driver:
This generates the transmission pulses wave from the trigger.
HV Monitor:
This monitors the high voltage for transmission and keeps it in range.
RECEIVER
Some manufacturers name this block amplifier, other name it receive focusing, this block receives the electric signals coming from the probe, and makes the analogue processing for it to be suitable for medical diagnostic. The principal function of this block is to compensate the ultrasound lines transmitted which drops exponential it´s amplitude while going deep inside the human body, to revert this effect the receiver must apply a logarithmic amplification, it is named (TGC) Time Gain Compensation [2], this is done automatically but it also may be modified by the ultrasound equipment operator.
The signal after been processed by the TGC is sent to the next block for processing the echo, or to the continuous Doppler block that is an optional block.
ECHO PROCESSING
At the input of the echo processing the echoes are converted to digital signal. As the echo analogue processing done in the receiver block, there is an echo digital processing done in the echo processing block, one of this processing is the focus in reception, and it is done by the beam former, the echoes arrive at the probe at different time, so the echoes that arrive first have to be delayed to be all in phase for the adding action (arrive at the adding circuit at the same time) to create the focus as it is seen in figure 4 [2].
After the reception focusing other task is also is done, the compression of the signal, contrast, gains, and so forth.
FIG 3
Fig 4