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Impedance Cardiography and Cardiac Output


AcqKnowledge offers a comprehensive array of noninvasive impedance cardiography (ICG) tools for recording parameters associated with virtually any kind of biological electrical bioimpedance monitoring. Extracted measures can be displayed as new channels in the recording, or exported to an Excel spreadsheet or Journal file for further analysis. In addition to conventional BIOPAC data acquisition hardware, record wirelessly with the BioNomadix BN-NICO system.

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AcqKnowledge offers two primary methods for extracting impedance cardiography parameters:

Method 1: Automated dZ/dt Classifier and ICG Analysis Routines

dZ/dt Classifier AcqKnowledge automatically scores the dZ/dt waveform with event markers indicating appropriate points in the complex to derive additional measures. Watch the ICG dZ-dt Classifier Tutorial Video.

ICG AnalysisAfter dZ/dt scoring, run the automated ICG analysis routine to derive a wide array of impedance and hemodynamic measures, such as stroke volume, cardiac output, heart rate, R-R interval, mean blood pressure and more. Individual measures can be toggled on or off, allowing a customized subset of measurement data to be included in the output.

Measures extracted by ICG Analysis:

Acceleration Index (AI)
Cardiac Index (CI)
Cardiac Output (CO)
Heart Rate (HR)
Left Cardiac Work (LCW)
Left Cardiac Work Index (LCWI)
Left Ventricular Ejection Period (LVEP)
Mean Blood Pressure (MBP)
Mean Central Venous Pressure (CVP)
Mean Pulmonary Artery Pressure (PA)
Pre-ejection Period (PEP)
RR Interval (RR)
Stroke Index (SI)
Stroke Volume (SV)
Systemic Vascular Resistance (SVR)
Systemic Vascular Resistance Index (SVRI)
Systolic Time Ratio (STR)
Thoracic Fluid Content (TFC)
Thoracic Fluid Index (TFCI)
Velocity Index (VI)

Method 2: Ensemble Averaging

ICG Ensemble Average dZdt

Ensemble Average – Use this Analysis menu feature to average user-selected areas of a data file, such as baseline, recovery, or intervals of cleaner data. Extremely useful for impedance cardiography and ECG signal analysis, ensemble averaging passes can be located around data-driven peak detection, or from user-defined events surrounding areas of interest. Averages of multiple channels can be extracted simultaneously and consolidated into a single graph window, clearly displaying the results. Analyze the entire data set or select the output from pre-defined focus areas in the graph. Watch the Ensemble Averaging Tutorial Video.

Additional Impedance Cardiography tools for extracting advanced measures and cleaning data

Body Surface Area Determine body surface area estimation in square meters for a subject of a given height and weight, using formulas available in the ICG Preferences.

Derive dZ-dt from Raw Z A convenience utility for working with impedances recorded using the BIOPAC EBI100C amplifier or the raw impedance output of the BIOPAC NICO100C module.

Ideal Body Weight Derive ideal body weight from person’s height, gender and frame size using a number of provided industry-standard methods. (Body Weight computations are configurable in Preferences.) Ideal Body Weight results are always expressed in kilograms.

Pre-ejection PeriodMeasure the time interval between the electromechanical systole and the onset of ejection of blood from the left ventricle of the heart.

dZ/dt Remove Motion Artifacts Apply motion artifact removal to a dZ/dt signal. Uses cycle information from an ECG signal to construct a model of the ICG signal containing only the components correlated to the heart rate.

VEPTCompute the volume of electrically participating tissue (VEPT) in cubic centimeters. This is calculated by entering the height of the subject.


Application Notes

Knowledge Base

Hardware Packages   |   Impedance Cardiography and Cardiac Output

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