Evaluation of dual-tip micromanometers during 21-day implantation in goats

• Published in: Medical engineering & physics Vol. 20; no. 6; pp. 410 - 417
• Main Authors: Reister, C.A, Koenig, S.C, Schaub, J.D, Ewert, D.L, Swope, R.D, Latham, R.D, Fanton, J.W
• Format: Journal Article
• Language: English
• Published: Legacy CDMS Elsevier Ltd 01.09.1998; Elsevier Science
• Subjects: Animals; Biological and medical sciences; Biomedical Engineering; blood pressure; Blood Pressure Determination - instrumentation; Blood Pressure Determination - statistics & numerical data; cardiac; Cardiac Catheterization - instrumentation; Cardiovascular Physiological Phenomena; catheter; Catheters, Indwelling; chronic; Evaluation Studies as Topic; Fundamental and applied biological sciences. Psychology; Goats; Hemodynamics; Hemodynamics. Rheology; invasive; Life Sciences (General); Male; Manometry - instrumentation; Manometry - statistics & numerical data; measurement; micromanometer; Prostheses and Implants; Space life sciences; Time Factors; Vertebrates: cardiovascular system; blood pressure; catheter; invasive; micromanometer; chronic; measurement; cardiac; Non-Nasa Center; Nasa Discipline Cardiopulmonary; Cardiovascular control; Parameter estimation; Sensitivity analysis; Implanted material; Vertebrata; Mammalia; Animal; Surgery; Goat; Manometer; Artiodactyla; Circulatory system; Hemodynamics; Pressure measurement; Microstructure; Ungulata; Comparative study; NASA Discipline Cardiopulmonary; Non-NASA Center
• ISSN: 1350-4533; 1873-4030
• DOI: 10.1016/S1350-4533(98)00049-6

Investigative 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.