Multichannel Systems LTP-Director Manual - Manual (Page 41)

LTP-Director
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The four peristaltic pumps P1 to P4 from the left side of the device control the inlet tubes,
independent from each other. They are connected to the compound bottles. The fifth peristaltic
pump on the right side of the device controls the outlet tube, connected to the waste bottle.
This pump works additionally as soon as one of the inlet pumps is activated and is connected
to a bubble detector. The outlet pump runs as fast as all other active pumps together multiplied
by 1.5 to guarantee that overflow is not possible. You can apply three compounds of your choice.
It is recommended to have the perfusion dilution used as standard in the experiment, for example
Ringer’s solution, as forth compound. When starting more than one inlet peristaltic pump you can
mix compounds in any desired ratio by the velocity of the influx.
The bubble detector connected to the outlet pump prevents overflow. A light barrier detects
the changes of fluid to air in the outlet tube and measures whether this event takes place all
ten seconds or not. The LED indicates the fluid flow: The LED is permanently on without tube,
when the fluid flow is not correct it flashes fast, with correct flow the LED flashes slow. Please
pay attention to the LED.
Please use the dialog in the “Hardware” “Perfusion” tab for manual control of the PPS5 device.
For example, you can use it to eliminate the air in the tubes before starting an experiment.
Select the velocity of fluid transport via up down menus in the dialog window. The upper limit
is 5000 and the unit is roughly microliters per minute, so the maximum is 5 ml/min.
Click the button “On/Off” to start the peristaltic pump, click the button again to stop the pump.
It is possible to change the velocity via up down menu or by writing into the window while
the pump is running. When starting any of the inlet pumps, the outlet pump is automatically
activated, and the speed is always adjusted to the total of all other pumps times 1.5.
Important: When changing from Test Mode in Measurement Mode the pumps are running as
defined in the “Perfusion” dialog, until the first valid experimental phase starts. Then pump P1
to P3 are automatically stopped, pump 4 (P4 Ringer) continuous running. In the drug application
phase you can set new parameters for pump P1 to P4 in the “Drug Recording” dialog, which are
applied in this phase and the following phases until wash out phase is reached. During wash out
phase and all following phases only pump 4 (P4 Ringer) is working, that means only Ringer, for
example, is applied but no compound any longer.
In the main control panel there is a “Start” and “Stop” button for the perfusion. By pressing the
“Start” button, only pump 4 (P4 Ringer) is activated. The status of pumps P1 to P3 is unaffected.
The “Stop” button stops all pumps. These buttons are available in Test Mode and in Measurement
Mode.