Model 1025 Technical Tips
(last update September, 2006)
Click on the red gate indication
in the Cardio Sweep and/or Resp Sweep portion of the display to
place the gate indication directly on the waveform.
When the red box is clicked, it changes color to green and the waveform
changes color to indicate the timing of the gate. Clicking the white
output gate indicator works in a similar manner.
R-detect markers - the latest PC-sam software (version
5.12) automatically draws lines on the ECG waveform to indicate
the three points that satisfy the R-detect gate. The three lines
appear when the R-detect window is open as long as gates are generated.
This is a very useful tool in setting the slope criteria for optimal
ECG gating.
Boot the PC with the serial
cable disconnected to keep some versions of the Windows
operating system from automatically assigning the serial port to
a mouse. If the serial mouse assignment is made, data from the Control/Gating
Module will cause the cursor to move erratically on the display.
Connect the serial cable after booting the PC for normal operation.
The R-detect blanking period can be a very useful tool to eliminate false gates caused by interference in the ECG waveform. >> Download the gating setup file for details. (PDF - 7kb)
A cover for the rectal temperature probe can be used to insulate a defective probe. The small rectal probe for use with mice is delicate and can easily develop cracks in the epoxy coating. The probe, which measures temperature using a small voltage, if cracked can create an offset voltage in the ECG waveform. If the offset voltage is large the ECG waveform becomes a flat line and an "ECG Leadoff" error is reported. To identify that the error is due to a defective probe, disconnect it from the ECG/Temperature Module. If the offset voltage reported in the SYSTEM INFO window become +2.5 V +/- 1.0 V the probe is defective.
Probe covers designed for digital thermometers are available from most drug stores or from SAII. Place the cover over the probe and apply a small amount of lubricant before insertion into the rectum.
Test the ECG/Temperature Module’s Battery Pack and cable by holding the ECG/Temperature Module and Batter Pack with one hand so that the Battery Pack connections are visible. Connect the Battery Pack Cable with the other hand and observe red light in the module’s fiber optic port. Gently move the cable at each connection. Any interruption of light from the fiber optic port would indicate a potential short in the cable or connections.
Test for proper communication between the PC and Control/Gating Module by displaying a respiration waveform (either E-resp or P-resp) and the corresponding gate in the Cardio sweep display. Check and uncheck the corresponding "invert pulse" box in the GATING window and observe the gate switching between inspiration and expiration in less than 2 seconds.
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