We propose a deadbeat controller for the control of pulsatile pump flow (Q(p) ) in an implantable rotary blood pump (IRBP). Noninvasive measurements of pump speed and current are used as inputs to a dynamical model of Q(p) estimation, previously developed and verified in our laboratory. The controller was tested using a lumped parameter model of the cardiovascular system (CVS), in combination with the stable dynamical models of Q(p) and differential pressure (head) estimation for the IRBP. The control algorithm was tested with both constant and sinusoidal reference Q(p) as input to the CVS model. Results showed that the controller was able to track the reference input with minimal error in the presence of model uncertainty. Furthermore, Q(p) was shown to settle to the desired reference value within a finite number of sampling periods. Our results also indicated that counterpulsation yields the minimum left ventricular stroke work, left ventricular end diastolic volume, and aortic pulse pressure, without significantly affecting mean cardiac output and aortic pressure.
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http://dx.doi.org/10.1111/j.1525-1594.2011.01268.x | DOI Listing |
Dent Mater
January 2025
Department of Materials, School of Natural Sciences, University of Manchester, Manchester M13 9PL, UK; Photon Science Institute, University of Manchester, Manchester M13 9PL, UK. Electronic address:
Objective: To assess the impact of mechanical decontamination using rotary brushes on the surface topography, elemental composition, roughness, and wettability of titanium implant surfaces.
Methods: Four commercially available rotary brushes were used: Labrida BioClean Brush® (LB), i-Brush1 (IB), NiTiBrush Nano (NiTiB), and Peri-implantitis Brush (PIB). Seventy-five titanium discs with sandblasted, large-grit, acid-etched (SLA) surfaces were randomly assigned to five groups (n = 15): LB, IB, NiTiB, PIB, and a control group.
Int J Implant Dent
December 2024
Department of Oral and Maxillofacial Surgery, University Medical Center, Johannes Gutenberg University, Augustusplatz 2, 55131, Mainz, Germany.
Purpose: To evaluate whether there are clinical benefits by preparing dental implant sites using piezosurgery instead of conventional rotary drills in healed bone crests and if initial crestal soft tissue thickness could have an impact on marginal bone loss.
Methods: Twenty-five partially edentulous patients requiring two single implants in molar/premolar areas had each site randomly allocated to either piezosurgery or to conventional rotary drill preparation according to a split-mouth design. Definitive screw-retained metal-ceramic crowns were delivered after 6 months.
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 PDFInt J Biol Macromol
December 2024
State Key Laboratory of Fine Chemicals, Dalian R&D Center for Stem Cell and Tissue Engineering, Dalian University of Technology, Dalian 116024, China. Electronic address:
Bioreactor can provide a dynamic culture environment for the in vitro construction of osteochondral tissue engineering. They facilitate more efficient exchange of nutrients and provide mechanical and other beneficial stimulation. Previous findings demonstrated that rotary flask (RF) bioreactor, rotary cell culture system (RCCS), or electromagnetic field (EMF) mediated scaffold culture could create a favorable dynamic environment for osteochondral tissue engineering.
View Article and Find Full Text PDFActa Biomater
January 2025
Medical Research Institute, Department of Orthopedics, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou 510080, China. Electronic address:
Recently, molybdenum (Mo) has been recognized a promising biodegradable metal, however, it is difficult to be processed through traditional deformation or machining due to its high strength & hardness. Additive manufacturing is a good way to get rid of this dilemma. Here, Mo components were directly fabricated with fine Mo powder through selective laser melting (SLM).
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