Detection of inflow obstruction in left ventricular assist devices by accelerometer: An in vitro study. (December 2022)

• Record Type: Journal Article
• Authors: Lilja, Didrik; Schalit, Itai; Espinoza, Andreas; Pettersen, Fred-Johan; Elle, Ole Jakob; Halvorsen, Per Steinar
• Is Part Of: Medical engineering & physics. Volume 110(2022)
• Publication Date: 2022-12
• Subjects: Accelerometer -- LVAD -- Inflow obstructions -- Pump vibrations -- Detection; LVAD left ventricular assist device; Biomedical engineering -- Periodicals; Biomedical Engineering -- Periodicals; Physics -- Periodicals; Génie biomédical -- Périodiques; Biomedical engineering; Electronic journals; Periodicals; 610.28
• DOI: 10.1016/j.medengphy.2022.103917
• Languages: English
• ISSNs: 1350-4533

Abstract

Highlights: An accelerometer detects inflow obstructions in left ventricular assist devices. Inflow obstructions-related vibrations emerge before the pump flow reduces. Accelerometer-captured vibrations may warn about inflow obstructions. An accelerometer had better diagnostic accuracy than the pump power consumption. Abstract: Inflow obstruction in left ventricular assist devices (LVAD) may lead to embolic stroke and pump malfunction. We investigated if an accelerometer detected graded LVAD inflow obstructions. Detection performances were compared to the current continuous surveillance routine based on the pump power consumption ( P LVAD ). In ten mock circuit experiments, four different-sized pendulating balloons obstructed HVAD™ inflow conduits cross-section areas by 14%-75%. Nonharmonic amplitudes (NHA) of continuous signals from a triaxial accelerometer attached to the LVAD were compared against single-point P LVAD values, using load and speed alterations as control interventions. We analyzed the NHA band power with a pairwise nonparametric statistical test. The detection performances were analyzed by receiver operating characteristics with areas under the curves (AUC). The NHA remained unaffected during load alterations. In contrast, NHA increased significantly from the 27% obstruction level (AUC≥0.82), an effect amplified by increased pump speed. P LVAD did not change significantly below the maximal 75% obstruction level (AUC≤0.36). In conclusion, NHA detected the inflow obstructions much better than P LVAD . The technique may provide a future monitoring modality of any pendulating obstructive inflow pathology. Graphical Abstract: Image, graphical abstract