VU-AMS derived cardiac function measures:
validity and field studies
H. Riese1, M. van den Berg1, T.G.M. Vrijkotte2, G. Willemsen1 and E.J.C. de Geus1
1Department of Biological Psychology, Vrije Universiteit, Amsterdam, The Netherlands
2AMC, Amsterdam, The Netherlands
To acquire and analyse data recorded with the Vrije Universiteit - Ambulatory Monitoring System (VU-AMS), an accompanying software package is available. This presentation will focus on the analysis of impedance cardiogram (ICG) data using the scoring program AMSIMP. This program contains an automatic scoring algorithm for detecting 3 specific points in each ICG complex, which are then used to calculate several physiological variables. The program also allows the user to change these points manually. A new feature of the program allows averaging across multiple complexes and activities prior to scoring, which considerably reduces the scoring time. The validity of this method will be discussed, using comparison data from 3,000 individually scored ICG complexes and the scoring of averaged complexes.
Besides validity, the stability of cardiac function measures is also important. Analysis of two subsequent 24-hr workday registrations has shown high test/re-test correlations for absolute PEP values. Test/re-test correlations for various PEP reactivity measures were also highly significant. Additional results for other cardiac function measures, e.g. stroke volume, will also be presented.
Paper presented at Measuring Behavior 2002 , 4th International Conference on Methods and Techniques in Behavioral Research, 27-30 August 2002, Amsterdam, The Netherlands