Non-invasive flow estimation in an implantable rotary blood pump: a study considering non-pulsatile and pulsatile flows
Autor: | Peter J. Ayre, Nigel H. Lovell, J C Woodard |
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Rok vydání: | 2003 |
Předmět: |
Materials science
Physiology Biomedical Engineering Biophysics Pulsatile flow Hematocrit Muscle Smooth Vascular Veins Root mean square Impeller Control theory Physiology (medical) medicine Animals Heart-Assist Devices Sheep medicine.diagnostic_test Models Cardiovascular Equipment Design Prostheses and Implants Blood pump medicine.anatomical_structure Models Animal Vascular resistance Vascular Resistance Algorithms Blood Flow Velocity Software Venous return curve Biomedical engineering |
Zdroj: | Physiological Measurement. 24:179-189 |
ISSN: | 0967-3334 |
DOI: | 10.1088/0967-3334/24/1/313 |
Popis: | Non-invasive estimation of flow was investigated in an implantable rotary blood pump (iRBP) with a hydrodynamic bearing. The effects of non-pulsatile and pulsatile flows were studied using in vitro mock loops, and acute (N = 3) and chronic (N = 6) ovine experiments. Using the non-pulsatile and pulsatile mock loops an average flow estimation algorithm was derived from root mean square (RMS) pump impeller speed and RMS input power. These algorithms were programmed into the iRBP controller for subsequent validation in vivo. In the acute experiments, venous return and systemic vascular resistance were adjusted through pharmacological intervention and exsanguination to produce an average range of pump flows from 0.0 to 2.6 l min(-1). Over this range the RMS estimation error was 88 +/- 12 ml, with a linear correlation slope of 0.992 +/- 0.006 (R2 = 0.986 +/- 0.004). In the chronic experiments, animals were monitored daily for up to three months and an average range of flows from 2.8 to 4.8 l min(-1) recorded. A linear correlation between the estimated and measured pump flows yielded a slope of 1.005 +/- 0.006 (R2 = 0.966 +/- 0.004). The RMS estimation error was 120 +/- 11 ml. Using this algorithm it is possible to effectively estimate flow in a rotary blood pump without implanting additional invasive sensors. |
Databáze: | OpenAIRE |
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