Aspect BIS VIEW, Руководство по эксплуатации

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SECTION 3 PRINCIPLES OF OPERATION
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3-6
BISx Power Supply (Patented technology)
The BISx derives power from the monitor. Power supply circuitry produces the necessary
voltages for operation. Power for patient-connected circuits is provided through an isolation
transformer. These circuits are isolated for patient safety.
3.2.1.4 The BISx Mechanicals
The BISx is contained in a small custom designed plastic case (see Figure 4). It is connected
to the monitor via the Monitor Interface Cable and connects to the BIS sensor via the
Patient Interface Cable (PIC). Both cables are strain relieved. The cables and the BISx
Bulkhead Connector (used to attach the PIC to the BISx) can be replaced, if necessary, by a
qualified biomedical engineering technician. The attachment clip on the back of the BISx
may be used to secure it to a convenient location near the patient’s head.
There are no ventilation holes in the BISx case. It will not leak when splashed with liquids.
The case is electrically shielded both to prevent spurious emissions from the BISx and to
prevent externally caused interference with the BISx circuits.
3.2.2 The BIS VIEW Monitor
The BIS VIEW monitor contains the circuits to enable the soft keys, to receive processed
parameters from the BISx, to display the data on the screen, and to communicate with other
devices via USB and RS-232 ports.
The monitor also contains the circuits for powering the monitor and the BISx. An on board
annunciator generates alarm sounds.
A block diagram depicting the monitor subassemblies appears in Figure 5. A data flow
diagram appears in Figure 6. The signals are acquired, digitized, filtered, and processed by
the BISx. The BISx multiplexes the signals onto the BISx communications line. The data are
de-multiplexed in the monitor for display.
The Main board, with the card engine, controls all inputs and outputs, power, data memory,
and clock functions. The Card Engine also controls the screen display, the internal power
supplies, the monitor data communications and general sequencing of the internal computer
and power supplies.
The Connector board connects the reset button, USB and serial ports to the main board.
There are two USB ports. The USB Type A port is used to export data to a removable drive.
It is also used to upgrade monitor and BISx software. The USB (Type B) port is for
manufacturer’s use only. The RS-232 serial port can be used to transfer data from the
monitor.
All exposed metal parts on the rear of the BIS VISTA monitor are separated from live parts
by double insulation. Although some metal parts may be wired to carry functional current to
earth ground, they are not wired for safety current. Therefore a ground continuity test is not
recommended.