Background: At present, most clinically implanted rotary blood pumps are operated at constant speed and adjusted by the physician. It is generally assumed that an adaptation of pump speed to the patient's physiologic requirements would be beneficial. The data provided in this paper, based on hemodynamic and spirometric data during exercise in which a pre-load-sensitive control was used, lend quantitative support to this assumption.
Methods: An automatic speed control was developed and implemented with Matlab on a dSpace controller board. The system uses pump speed, pump power, and pump flow as its only input signals. It was connected to the clinical hardware of the DeBakey VAD System. The control is pre-load-sensitive and uses an expert system to detect excessive unloading and eventual suction. This system was used to quantify the cardiovascular reaction of patients to both automatically controlled and constant pump speed. A sub-group of 5 patients underwent bicycle ergometry with Swan-Ganz catheterization and spiroergometry.
Results: The automatic, closed-loop speed control showed robust and stable performance. It provided an increase in pump flow (+0.94 +/- 0.5 liters/min, p < 0.05) compared with constant-speed mode in response to physical activity. Pulmonary arterial (PAP) and capillary wedge pressure (PCWP) clearly decreased (-7.4 +/- 4.1 mm Hg for PAP and -8.3 +/- 4.2 mm Hg for PCWP, p < 0.05), and venous oxygen saturation moderately increased (+5.2%).
Conclusion: An automatic speed-control system for rotary blood pumps was developed and demonstrated by spiroergometry to be appropriately responsive to physiologic demand.
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http://dx.doi.org/10.1016/j.healun.2005.09.008 | DOI Listing |
Monash Bioeth Rev
December 2024
Berman Institute of Bioethics, Johns Hopkins University, 1809 Ashland Ave, Baltimore, MD, 21205, USA.
Healthcare delivery and access, both in the United States and globally, were negatively affected during the entirety of the COVID-19 pandemic. This was particularly true during the first year when countries grappled with high rates of illness and implemented non-pharmaceutical interventions such as stay-at-home orders. Among children with special healthcare needs, research from the United Kingdom (U.
View Article and Find Full Text PDFBackground: The Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2021 provides a comprehensive assessment of health and risk factor trends at global, regional, national, and subnational levels. This study aims to examine the burden of diseases, injuries, and risk factors in the USA and highlight the disparities in health outcomes across different states.
Methods: GBD 2021 analysed trends in mortality, morbidity, and disability for 371 diseases and injuries and 88 risk factors in the USA between 1990 and 2021.
ASAIO J
December 2024
From the Department of Cardiac Surgery, LMU University Hospital, Ludwig Maximilian University Munich, Munich, Germany.
Continuous-flow left ventricular assist devices have become an important treatment option for patients with advanced heart failure. However, adverse hemodynamic effects as consequence of an altered blood flow within the aorta and the aortic root remain a topic of concern. In this work, we investigated the influence of the outflow graft orientation on the hemodynamic profile and flow parameters within the thoracic aorta.
View Article and Find Full Text PDFPharmaceuticals (Basel)
November 2024
Pathfinder Research and Training Foundation, Gr. Noida 201308, India.
Gout is a chronic inflammatory condition characterized by elevated uric acid levels in the blood, which can precipitate acute gout attacks in individuals with genetic susceptibility, existing medical conditions, and dietary influences. Genetic predispositions, comorbid medical conditions, nutritional choices, and environmental factors increasingly recognize the multifactorial etiology of the disease. Recent research has highlighted the potential of phytochemicals, particularly flavonoids, saponins, and alkaloids, to manage hyperuricemia (HUA) and its associated complications.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!