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Evaluation of dual-tip micromanometers during 21-day implantation in goatsInvestigative research efforts using a cardiovascular model required the determination of central circulatory haemodynamic and arterial system parameters for the evaluation of cardiovascular performance. These calculations required continuous beat-to-beat measurement of pressure within the four chambers of the heart and great vessels. Sensitivity and offset drift, longevity, and sources of error for eight 3F dual-tipped micromanometers were determined during 21 days of implantation in goats. Subjects were instrumented with pairs of chronically implanted fluid-filled access catheters in the left and right ventricles, through which dual-tipped (test) micromanometers were chronically inserted and single-tip (standard) micromanometers were acutely inserted. Acutely inserted sensors were calibrated daily and measured pressures were compared in vivo to the chronically inserted sensors. Comparison of the pre- and post-gain calibration of the chronically inserted sensors showed a mean sensitivity drift of 1.0 +/- 0.4% (99% confidence, n = 9 sensors) and mean offset drift of 5.0 +/- 1.5 mmHg (99% confidence, n = 9 sensors). Potential sources of error for these drifts were identified, and included measurement system inaccuracies, temperature drift, hydrostatic column gradients, and dynamic pressure changes. Based upon these findings, we determined that these micromanometers may be chronically inserted in high-pressure chambers for up to 17 days with an acceptable error, but should be limited to acute (hours) insertions in low-pressure applications.
Document ID
Document Type
Reprint (Version printed in journal)
Reister, C. A. (Rothe Development Inc. San Antonio, TX, United States)
Koenig, S. C.
Schaub, J. D.
Ewert, D. L.
Swope, R. D.
Latham, R. D.
Fanton, J. W.
Convertino, V. A.
Date Acquired
August 22, 2013
Publication Date
September 1, 1998
Publication Information
Publication: Medical engineering & physics
Volume: 20
Issue: 6
ISSN: 1350-4533
Subject Category
Life Sciences (General)
Distribution Limits
Non-NASA Center
NASA Discipline Cardiopulmonary