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Flow Pump (flow + pump)
Selected AbstractsThe Meaning of the Turning Point of the Index of Motor Current Amplitude Curve in Controlling a Continuous Flow Pump or Evaluation of Left Ventricular FunctionARTIFICIAL ORGANS, Issue 3 2003G.J. Endo It is the goal of this section to publish material that provides information regarding specific issues, aspects of artificial organ application, approach, philosophy, suggestions, and/or thoughts for the future Abstract: In this series, we investigated the meaning of the t-point of index of motor current amplitude (ICA) curve from a point of view of flow rate on in vitro and in vivo studies. On mock circulation loop and left ventricular assist device (LVAD),equipped pigs, we detected the t-point and compared the pump flow at the t-point with the simultaneous cardiac output. The pump flow at the t-point showed high correlation against the simultaneous cardiac output for in vitro or in vivo study. By detection of the t-point of the ICA curve and measuring or estimating the pump flow at t-point, the cardiac output may be assessed without any sensor in various cardiac conditions. [source] MRA of intracranial aneurysms embolized with platinum coils: A vascular phantom study at 1.5T and 3TJOURNAL OF MAGNETIC RESONANCE IMAGING, Issue 1 2008Shingo Kakeda Abstract Purpose To analyze the influence of matrix and echo time (TE) of three-dimensional time-of-flight (3D TOF) magnetic resonance angiography (MRA) on the depiction of residual flow in aneurysms embolized with platinum coils at 1.5T and 3T. Materials and Methods A simulated intracranial aneurysm of the vascular phantom was loosely packed to maintain the patency of some residual aneurysmal lumen with platinum coils and connected to an electromagnetic flow pump with pulsatile flow. MRAs were obtained altering the matrix and TE of 3D TOF sequences at 1.5T and 3T. Results The increased spatial resolution and the shorter TE offered better image quality at 3T. For the depiction of an aneurysm remnant, the high-spatial-resolution 3T MRA (matrix size of 384 × 224 and 512 × 256) with a short TE of ,3.3 msec were superior to the 1.5T MRA obtained with any sequences. Conclusion 3T MRA is superior to 1.5T MRA for the assessment of aneurysms embolized with platinum coils; the combination of the 512 × 256 matrix and short TE (3.3 msec or less) seems feasible at 3T. J. Magn. Reson. Imaging 2008;28:13,20. © 2008 Wiley-Liss, Inc. [source] Delivery of nebulized budesonide is affected by nebulizer type and breathing patternJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 6 2005C. O'Callaghan The aim of this study was to determine the output in-vitro of budesonide from two different nebulizers under simulated breathing conditions. The BimboNeb and Nebula nebulizers were used to nebulize 2 mL of budesonide (500 ,g) suspension. Particle size was determined by inertial impaction after a 5-min nebulization. Total outputs of the drug from both nebulizers were measured using a sinus flow pump to create simulated breathing conditions. Paediatric and adult breathing patterns were used, with drug output measured after 5 and 10 min nebulization. The mass median aerodynamic diameter of budesonide using the BimboNeb (4.5 ,m) was significantly greater than that from the Nebula (3.4 ,m) (P < 0.01). With the simulated adult breathing pattern, the total drug output after 5 min with the BimboNeb (61.5 ,g) was twice that from the Nebula (30.7 ,g). For the paediatric breathing pattern, total outputs were very similar for both nebulizers. In all cases, nebulizing for 10 min produced greater drug outputs compared with those after 5 min, particularly for the paediatric breathing pattern. The amount of aerosolized drug available for inhalation needs to be assessed for each nebuliser used and the effect of the patient's breathing pattern should also be taken into account. [source] The output of flunisolide from different nebulisersJOURNAL OF PHARMACY AND PHARMACOLOGY: AN INTERNATI ONAL JOURNAL OF PHARMACEUTICAL SCIENCE, Issue 4 2002Chris O'Callaghan The objective of this study was to determine the output, in-vitro, solution of a concentrated solution of flunisolide from two different nebulisers under simulated breathing conditions. The BimboNeb and Nebula nebulisers were used to nebulise 2.6 mL of flunisolide solution (600 ,g). Particle size was determined by inertial impaction and the total output of drug from the nebulisers under simulated breathing conditions was measured using a sinus flow pump. Two different breathing patterns were used, simulating nebuliser use by a child and an adult. The mass median aerodynamic diameter of flunisolide particles from the BimboNeb and Nebula were both 3.9 ,m. With the simulated paediatric breathing pattern, both nebulisers delivered similar amounts of flunisolide (56.4 ,g (s.d. 1.4,g) and 56.1 ,g (5 ,g) over 5 min from the BimboNeb and Nebula, respectively). With the adult breathing pattern, flunisolide delivery from the BimboNeb was increased to 88.9 ,g (3.3 ,g), but delivery from the Nebula was only slightly increased to 64.6 ,g (1.4 ,g). With both nebulisers, little drug was released after 5 min of nebulisation. Both nebulisers delivered 9,15 % of the nominal dose of flunisolide to the breathing simulator, a similar percentage to previous studies with budesonide and more than previous studies with beclometasone. Drug delivery from the BimboNeb, but not the Nebula, was affected by the simulated breathing pattern. This study suggests that drug delivery from nebulisers is dependent upon the interaction between the nebuliser, the drug and the patient. [source] Patient Satisfaction With the External Equipment of Implantable Left Ventricular Assist DevicesARTIFICIAL ORGANS, Issue 9 2010Anna L. Meyer Abstract Patient satisfaction with left ventricular assist device (LVAD) external equipment has not yet been reported. We aimed to evaluate the quality of two different systems based on patients' perspective and its interrelationship with quality of life. Differential assessment of the HeartMate II axial flow pump (n = 17; Thoratec, Pleasanton, CA, USA) and the HVAD centrifugal pump (n = 10; HeartWare, Inc., Miramar, FL, USA) was obtained from 27 outpatients by a questionnaire 2 months to 2.9 years after device implantation. In addition, a health-related quality of life questionnaire (Short Form-36 [SF-36]) was completed. Overall patients' satisfaction was high. Severe limitations were attributed to the loudness of the power base unit in HeartMate II patients (P = 0.00), and HVAD patients were dissatisfied by the length of the driveline (P = 0.02). Between HVAD and HeartMate II patients, no significant differences in the quality of life (assessed by SF-36) were reported. While the overall satisfaction of outpatients on LVAD support was high, differences between the systems were found. Patients' perspectives may have an important impact on future modification of external components. Ultimately, this may also contribute to an improvement in the quality of life of chronic LVAD patients. [source] Design of a Protective Cage for an Intravascular Axial Flow Blood Pump to Mechanically Assist the Failing FontanARTIFICIAL ORGANS, Issue 8 2009Amy L. Throckmorton Abstract Currently, no long-term mechanical bridge-to-transplant or bridge-to-recovery therapeutic alternative exists for failing single ventricles. A blood pump that would augment pressure in the cavopulmonary circulation is needed, and would lead to a reduction in elevated systemic venous pressure, and improve cardiac output. Thus, we are developing a collapsible, percutaneously inserted, axial flow blood pump to support the cavopulmonary circulation in adult patients with a failing single ventricle physiology. This collapsible axial flow pump is designed for percutaneous positioning. The outer protective cage will be designed with radially arranged filaments as touchdown surfaces to protect the vessel wall from the rotating components. This study examined the geometric characteristics of the protective cage of filaments and the impeller through the development and numerical analysis of 13 models. A blood damage analysis was also performed on selected geometric models to assess the probability of blood trauma. All models demonstrated an acceptable hydraulic performance by delivering 2,6 L/min at a rotational speed of 6000,10 000 rpm and generating pressure rise of 5,20 mm Hg. Expected trends in the hydraulic performance of the pump models were found. This study represents the initial first design phase of the impeller and protective cage of filaments. Validation of these flow and performance predictions will be completed in the next round of experimental testing with blood bag evaluation. [source] Recent Progress in Artificial Organ Research at Tohoku UniversityARTIFICIAL ORGANS, Issue 1 2003Tomoyuki Yambe Abstract: Tohoku University has developed various artificial organs over the last 30 years. Pneumatic driven ventricular assist devices with a silicone ball valve have been designed by the flow visualization method, and clinical trials have been performed in Tohoku University Hospital. On the basis of these developments, a pneumatic driven total artificial heart has been developed and an animal experimental evaluation was conducted. The development of artificial organs in Tohoku University has now progressed to the totally implantable type using the transcutaneous energy transmission system with amorphous fibers for magnetic shielding. Examples of implantable systems include a vibrating flow pump for ventricular assist device, an artificial myocardium by the use of shape memory alloy with Peltier elements, and an artificial sphincter for patients with a stoma. An automatic control system for artificial organs had been developed for the ventricular assist devices including a rotary blood pump to avoid suction and to maintain left and right heart balance. Based upon the technology of automatic control algorithm, a new diagnostic tool for evaluating autonomic nerve function has been developed as a branch of artificial organ research and this new machine has been tested in Tohoku University Hospital. Tohoku University is following a variety of approaches aimed at innovation in artificial organs and medical engineering fields. [source] Miniature Vibrating Flow Blood Pump Using a Cross-Slider Mechanism for External Shunt CatheterARTIFICIAL ORGANS, Issue 1 2003S. Kawano Abstract: The prototype of the miniature vibrating flow pump (VFP) is developed for the external shunt catheter. The cross-slider mechanism is applied to vibrate the tube, which causes the pumping effect. This mechanism results in successful development of the miniature and lightweight VFP. By the use of the prototype VFP, the experiment of the basic pump performance is made in detail based on the authorized procedure in the research field of fluids engineering. The typical H - Q curve of VFP, which is the relationship between the pump head and the flow rate, can be obtained. This result suggests that the miniature VFP developed here can be expected to be used as the booster pump for the external shunt catheter in clinical applications. [source] Physiologic Benefits of Pulsatile Perfusion During Mechanical Circulatory Support for the Treatment of Acute and Chronic Heart Failure in AdultsARTIFICIAL ORGANS, Issue 7 2010Yulong Guan Abstract A growing population experiencing heart failure (100 000 patients/year), combined with a shortage of donor organs (less than 2200 hearts/year), has led to increased and expanded use of mechanical circulatory support (MCS) devices. MCS devices have successfully improved clinical outcomes, which are comparable with heart transplantation and result in better 1-year survival than optimal medical management therapies. The quality of perfusion provided during MCS therapy may play an important role in patient outcomes. Despite demonstrated physiologic benefits of pulsatile perfusion, continued use or development of pulsatile MCS devices has been widely abandoned in favor of continuous flow pumps owing to the large size and adverse risks events in the former class, which pose issues of thrombogenic surfaces, percutaneous lead infection, and durability. Next-generation MCS device development should ideally implement designs that offer the benefits of rotary pump technology while providing the physiologic benefits of pulsatile end-organ perfusion. [source] | ||||||||||