Ohmeda Ohio Care Plus, Руководство по эксплуатации и обслуживанию

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3/General Information
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Patient probe
In the air control mode, the patient probe has no affect on incubator operation;
connecting the probe simply displays the patient temperature for your information.
The patient control (servo) mode
In the patient control mode, the control temperature (patient control temperature)
corresponds to the desired patient skin temperature. To reach an incubator
temperature that will maintain the desired skin temperature the incubator control
system loops through the program shown in Figure 3-1. This program compares the
patient control temperature setting to the actual patient temperature and raises or
lowers the incubator temperature depending on whether the infant is hot or cold. The
incubator temperature that maintains the desired skin temperature is referred to as the
DET (Desired Environmental Temperature). The maximum DET that the incubator will
maintain is 39.0°C (102.2°F).
You can reduce the time required to reach the DET by preheating the incubator in
the air control mode before entering the patient control mode. The closer the air
temperature gets to the actual air temperature required to maintain the desired infant
skin
temperature, the sooner the incubator will stabilize the infant’s temperature in the
patient control mode. When you switch to the patient control mode, the previous air
control temperature becomes the initial DET. The incubator automatically adjusts the
DET using the three stage patient control mode program, shown in Figure 3-1.
The first stage of the loop checks to make sure that the patient probe is reporting a
reasonable patient temperature before making any adjustments. If the patient
temperature is less than 30°C (86.0°F) or above 42°C (107.6°F), the incubator assumes
that the patient probe has detached from the infant, the patient temperature alarm
triggers, the heater shuts off, and the DET remains unchanged.
The second stage of the loop calculates the PTG (Patient Temperature Gradient), the
difference between the actual patient temperature and the selected patient control
temperature, to determine if the infant is hot or cold. If the infant is too cold (PTG <
-0.5°C), the heater switches On. If the infant is too hot (PTG > 0.5°C), the heater shuts
down. The patient temperature continues to be checked every three seconds.
The third stage calculates the change in the patient temperature over the previous ten
minute period. If the infant temperature differs from the patient control temperature
setting by 0.2°C or more, and this difference has not decreased by at least 0.2°C
during the last ten minute period, the DET will be adjusted. To prevent large incubator
temperature swings and to allow time for the patient to respond to changes in the
incubator temperature, the magnitude of the change in the DET depends on the PTG.
Patient control temperature range
The patient control mode lets you enter air control temperatures from 35.0 to 37.0°C
(95.0 to 98.6°F) using the temperature switches (
?
and
M
). An internal
adjustment lets you increase the patient control temperature to 37.5°C (99.5°F).
Patient temperature alarm
Patient temperature alarm monitoring runs concurrently with the control loop. A patient
temperature alarm triggers if the patient temperature differs from the patient control
temperature by more than 1.0°C (1.8°F), or 0.5°C (0.9°F) with an internal adjustment.
Additional alarm routines verify proper operation and switch off the heater if the air
temperature exceeds 40.0°C (104.0°F).