VITACON VitaScan LT - System Component Descriptions; Functional Description; Microcontroller and FPGA; Microcontroller States of Operation

VitaScan LT
User and Service Manual
Funconal Descripon
The IVBM VUFE is a single element
ultrasound scanner with the electronic
module and scanning mechanics,
designed to t in a hand held scanner,
having the following main functionality:
• USB communication interface for
computer
• Ultrasound Pulse generator
• Ultrasound receiver and signal
processing
• Motor control and positioning of the
ultrasound transducer element
The module is realized in analog and
digital hardware, FPGA conguration, and
microcontroller rmware. The following are
the main parts of the design:
• Microcontroller
• FPGA
• PSU
• USB
• Motor driver
• Analogue Receiver and transmitter
Microcontroller
The microcontroller is the master in
the IVBM VUFE-module, controlling
all functionality and safety. It is also
a communication interface between
the probe and the computer. The
microcontroller is a slave with
respect to the computer, and will
only communicate in response to a
command from the computer.
Microcontroller states of operaon:
Power up:
At normal power up, a self-test
and initiation procedure will start.
The FPGA conguration will be
cleared and conguration must be
downloaded from the computer before
ultrasound acquisition may start. The
transducer element positions will be
initialized.
At power up with the push-button
pressed, the module will enter
“PROGRAM” mode, waiting for
rmware upgrade via the USB
connection. This is a maintenance
function, and should only be used by
trained service personnel.
Idle:
In Idle state, the module is waiting for
a command from the computer or the
pushbutton. The current consumption
is reduced to an absolute minimum.
Pre-Scan:
In Pre-Scan mode, the module will
move the transducer sweep-motor
continuously between the end
positions, and ultrasound data for
one vector will be transmitted to the
computer at each dened position.
The rotation-motor is parked in the
initial position. This will give the
computer the possibility to present a
“live” image of the bladder, making it
possible to move the VitaScan LT to
the correct position before making a
Full-Scan with volume calculation.
Full-Scan:
In Full-Scan mode, the module will
move the transducer sweep-motor
from one end position to the other,
transmitting ultrasound data for
one vector to the computer at each
dened position. The rotation motor
will then move one step, and a new
sweep will be performed. When the
rotation motor has moved a total of
180 degrees, and the computer has
received a number of vectors dening
a set.
FPGA:
The FPGA (Field Programmable Gate
Array) is responsible for all signal-
processing in the IVBM VUFE module.
The microcontroller congures the
FPGA with “Bitstream” data and
conguration data received by the
computer.
The microcontroller initiates an
“Ultrasound capture sequence” by a
Trigger signal. The FPGA will generate
an ultrasound pulse according to the
conguration data, receive the echo,
and send data for the vector to the
microcontroller after signal processing.
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