GE Voluson P6 Service Manual page 219

GE H RAFT
EALTHCARE
DIRECTION 5459672-100, R
5-2-3 Data Flow Control Description
This section describes the functions of the boards vs. different operation modes.
• BF64 - Beamformer Motherboard
• RFS - Mid-Processor, System Control and DMA Controlle
5-2-3-1 B-Mode
1.) RFS
The RFS contains the Clock-Management and PRF-Generator.
It generates(drives) BF(=Beamformer)-FPGA-Clock (200MHz) and Shot-Trigger for the
Beamformer board (BF64).
Configures PIR (Probe Interface board) and Beamformer (BF64 with Tx-Frequency, Tx-Focus, Rx-
Focus, LineNo (lateral Position), Tx- Apodization, RX-Apodization, Multibeam, etc. The RFS board
also contains the Tx-Power-Reference-DAC.
Furthermore it contains Multibeam-DeInterleave, Subtraction Filter (for HI-Mode, see:
3-1-1 "Special B-Mode Techniques" on page
Demodulator), LowPassFilter, Decimation (Pixel rate Conversion), Magnitude Calculator (Part of
Demodulator), Logarithmic Amplifier, Re-Sample, Edge Enhance (Contrast Enhancement through
differentiation), Frame Filter, Blending (adapting Brightness in order to perfectly combine Nearfield-
Frame with Farfield-Frame in FFC-Mode, see:
page
Multibeam-DeInterleave means: Incoming Pixel order
shot1pix1-shot2pix1-shot3pix1-shot4pix1 -
shot1pix2-shot2pix2-shot3pix2-shot4pix2...
is converted to the new order:
shot1pix1-shot1pix2-shot1pix3..... - shot2pix1-shot2pix2-shot2pix3.....
After DC-cancelling the signal is mixed with RX-Frequency and brought to LF-Spectrum, where the
LowPassFilter cuts HF. Mixer and Magnitude-Calculator arrange Complex Demodulation, and
Logarithmic Amplifier arrange the conversion from High-Dynamic LinearSignal to the Low-
Dynamik(e.g.8Bit) Log-Signal. Several Postprocessing steps (LineFilter, FrameFilter, ReSample,
Edge Enhance) enable smooth image quality while keeping contrast high.
a.) Direct Memory Access (DMA) section
2.) BF64 (Voluson® P8 / Voluson® P6)
This Beamformer board consists of Bemaformer-FPGA, TX-pulser, RX-AFE. BF64 supports 64 TX/
RX channels. Beamformer-FPGA generates TX-Frequency through dividing 200MHz by 2,3,4,5,...,
TX-Focus, and Sampling Clocks for the ADC, and manages RX-Foxcus (Delay and Chain-Adder)
and Apodization.
5-2-3-1-1 Special B-Mode Techniques
a.) HI (Coded Harmonic Imaging):
5-12
6 DRAFT (J
EVISION
5-12.
B-mode-Data from RFS is written via Signal Processor (SP) Channel 0 into SDRAM Fifo
Buffer memory. DMA Controller 0 transfers the data into PC main memory where scan
conversion is performed per software.
Cine Mode: Reserved area in PC main memory is used.
In one method of HI the RX-Frequency is doubled, so that the radial resolution is increased
due to the higher RX-Frequency.
The second method of HI is pulse-inversion: 2 TX-Beams are shot to the same Tissue-location,
one with positive, one with negative polarity. The subtraction of both shots (Subtraction Filter)
brings to bear the nonlinear-echo-reflection-properties of the tissue (especially in usage of
Contrast-medias), which is very useful with extremely difficult-to-image patients.
Section 5-2 - General Information
17, 2013)
ANUARY
5-12, DigitalTGC, DC-Canceler, Mixer (Part of
Section 5-2-3-1-1 "Special B-Mode Techniques" on
V ® P8 / V
OLUSON OLUSON
P S M
ROPRIETARY ERVICE
Section 5-2-
® P6
ANUAL