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iE33 Service Manual
CSIP Level 1
Theory of Operation: Acoustic Power and Intensity Manager (APIM)
toring is continuous in all operating states and shuts down the malfunctioning pulser supply
within two seconds of fault detection.
The current monitor, tracks the current through the NAIM regulator. The voltage monitor
tracks the input and output voltages on the NAIM regulator, and the watchdog timer automati-
cally disables the HV supplies if the current and voltage monitors are not being read by the FEC
Acoustic Power and Intensity Manager (APIM) software controls the acoustic power and the sur-
face temperature of the transducer face while under ultrasound system control. Acoustic power
and temperature limits are set by various regulatory agencies. The APIM monitors the output
power and temperature and ensures the parameters are not exceeded. For example, display of
output power parameters (MI, TI, SPTA) on the system monitor allows the user to compare
anatomy of one patient to another at a specific output value or to switch modes while keeping
the 2D output constant.
The APIM selects the appropriate voltage level that the FEC must use, given the current transmit
conditions of the ultrasound system and target output level. The voltage level is calculated based
on the system state, transducer data, AP&I data, and other factors. The voltage level is set so the
output power is as close as possible to the desired setting (MI, TI, or SPTA) without exceeding
the desired level. A power monitor on the FEC verifies that the FEC is consuming electric cur-
rent at the rate expected by the APIM.
Minor errors indicate that acoustic power and intensity may be calculated and the errors are
reported to the error log. Major errors specify conditions where acoustic power and intensity
cannot be calculated and scanning cannot be initiated for the condition.
Temperature monitoring in the Acquisition Card Cage is accomplished using 11 temperature
sensors. Two are on each Channel Board, two are on the NAIM, and one is on the FEC. The