Maquet HCU 40, Instructions For Use Manual

Page: 49 / 148

| HCU 40 | 4 Operation | 49 |
Instructions for Use | 1.0 | EN | 01
Copyright Maquet Cardiopulmonary GmbH
2 To accept the changes, touch the [Confirm] symbol.
Or
To reject them instead, touch the
[Reject] symbol.
Limits
Upper warning limit To change a limit value, touch the field and adjust the
value.
To deactivate the limit, increase the value until the touch­
screen displays
[– – –] .
To reactivate the limit, touch [–] until the touchscreen dis­
plays the desired limit value.
Lower warning limit To change a limit value, touch the field and adjust the
value.
To deactivate the limit, decrease the value until the touch­
screen displays
[– – –] .
To reactivate the limit, touch [+] until the touchscreen dis­
plays the desired limit value.
4.2.6 Gradient Mode
In gradient mode, setpoint gradients for the patient water circuit and cardioplegia
water circuit can be used for physiologically optimized warming and cooling.
The gradient (ΔT) is the temperature difference between the water outlet (T
out
)
and the externally measured temperature (T
ext
).
When the temperature sensor is connected in the venous line / in the venous
reservoir, the gradient for the patient water circuit is the maximum permissible
temperature difference between the circulating water and the venous blood.
The maximum permissible gradient for the cardioplegia water circuit is the
temperature difference between the circulating water and the cardioplegic fluid.
How Gradient mode functions
The maximum permissible gradient can be set in the Gradient mode. The HCU 40
then controls the warming/cooling in such a way that the water temperature does
not deviate from the externally measured water temperature by more than the set
maximum gradient. This means that the HCU 40 automatically adjusts the water
output temperature to the venous patient or cardioplegia temperature measured
by the sensor until the setpoint temperature (T
set
) at the water outlet is attained.
The Gradient mode thus protects the patient from too abrupt warming/cooling.