How do I connect a Codman ICP system to the PowerLab?

The Johnson and Johnson Codman ICP Express monitor for measuring inter-cranial pressure, is commonly used with the PowerLab data acquisition system to allow users to make recordings from the patients following surgery or trauma to the head. This main parameter measured is often the mean pressure recordings from the ICP Express Unit for prolonged periods (>24hrs).
As well as the Codman monitor and pressure catheter (not supplied by ADInstruments), a typical set up would include:
Full descriptions of how to interface the Codman ICP Express unit with PowerLab and LabChart software are attached as well as a typical Settings file.

The Codman unit only outputs ICP (and no other signals such as ECG).

From this, we can see that the Codman ICP System is responsible for subject isolation (not ADInstruments’ products - see ADInstruments Safety Standards).


ADInstruments MLAC21 Interface Cable (Datacard attached) then connects to the back of the Codman ICP box (as per attached picture) with the DIN plug connecting to Bridge Amp.

Note: The Codman ICP transducer should never be connected directly to ADInstruments Bridge Amp.

The output from the Codman unit simulates a normal transducer which is why we use a Bridge Amp to provide excitation etc. before recording into the PowerLab.

The Codman has two output gain settings (5uV/Vex/mmHg or 40uV/vex/mmHg – see “Patient Monitor Sensitivity Selection Switch on page 4 of IFU). The factory default is 5uV; however, we suggest that you set the output gain to 40uV/Vex/mmHg.

If the Codman output gain is set at 5uV/Vex/mmHg, then you will obtain a very low output (ie 20mmHg = 0.5mV) and low signal resolution in LabChart.

At this latter setting (40uV/Vex/mmHg), when used in conjunction with ADInstruments Bridge Amp (which provides 6V excitation), every 100mmHg input should give a 24mV output or 0.24mV per mmHg to the PowerLab.


Codman Unit.pdf

IFU ICP Box 82-6635.pdf