HIC-2000 and HIC-3000
Q: When using the HIC, how can the EKG signal sensitivity be adjusted?
A: The sensitivity of the EKG signal can be adjusted via an external gain control on the HIC-2000/3000 impedance cardiograph to achieve an appropriate EKG level. However, it is always best to use a separate external EKG electrode assembly (HIC2000ECG3) to achieve the best results, to have the greatest flexibility of electrode position, and to obtain the best signal possible.
Q: The external EKG seems erratic, having extremely high peaks. Could this be a problem with the external EKG cable?
A: Probably not. The problem is most likely that the EKG gain control, found on the front panel of the HIC, is too high. If the knob is turned counter-clockwise, the signal should reduce in intensity and look normal.
Q: The Zo value shown on the HIC-2000/3000 display is different from the value that appears on the COP-WIN display. Could this be due to the spike on the calibration waveform? How can this difference be fixed, and which value is the 'true' value?
A: The spike on the calibration waveform does not cause this difference. You may wish to recalibrate the HIC, however, to make the HIC displayed value and the COP-WIN value equal. Pressing the Calibrate and Zero buttons on the front panel of the HIC simultaneously can do this (see page 8 in the HIC manual). The Zo value indicated by COP-WIN is truly the correct value, assuming that the system has been calibrated recently.