912 resultados para forward pump


Relevância:

20.00% 20.00%

Publicador:

Resumo:

To investigate the efficacy of sensor-augmented pump therapy vs. multiple daily injection therapy in patients with suboptimally controlled Type 1 diabetes.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The eight pieces constituting this Meeting Report are summaries of presentations made during a panel session at the 2011 Association for Practical and Professional Ethics (APPE) annual meeting held between March 3rd and 6th in Cincinnati. Lisa Newton organized the session and served as chair. The panel of eight consisted both of pioneers in the field and more recent arrivals. It covered a range of topics from how the field has developed to where it should be going, from identification of issues needing further study to problems of training the next generation of engineers and engineering-ethics scholars.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Forward-looking ground penetrating radar shows promise for detection of improvised explosive devices in active war zones. Because of certain insurmountable physical limitations, post-processing algorithm development is the most popular research topic in this field. One such investigative avenue explores the worthiness of frequency analysis during data post-processing. Using the finite difference time domain numerical method, simulations are run to test both mine and clutter frequency response. Mines are found to respond strongest at low frequencies and cause periodic changes in ground penetrating radar frequency results. These results are called into question, however, when clutter, a phenomenon generally known to be random, is also found to cause periodic frequency effects. Possible causes, including simulation inaccuracy, are considered. Although the clutter models used are found to be inadequately random, specular reflections of differing periodicity are found to return from both the mine and the ground. The presence of these specular reflections offers a potential alternative method of determining a mine’s presence.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Rotary blood pumps (RBPs) running at a constant speed are routinely used for the mechanical support of the heart in various clinical applications, from short-term use in heart-lung machines to long-term support of a failing heart. Their operating range is delineated by suction and regurgitation events, leaving limited control on the cardiac workload. This study investigates whether different ratios of systolic/diastolic support are advantageous over a constant-speed operation.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

A prototype vortex-driven air lift pump was developed and experimentally evaluated. It was designed to be easily manufactured and scalable for arbitrary riser diameters. The model tested fit in a 2 inch diameter riser with six air injection nozzles through which airwas injected helically around the perimeter of the riser at an angle of 70º from pure tangential injection. The pump was intended to transport both water and sediment over a large range of submergence ratios. A test apparatus was designed to be able to simulate deep water or oceanic environments. The resulting test setup had a finite reservoir; over the course of a test, the submergence ratio varied from 0.48 to 0.39. For air injection pressures ranging from 10 to 60 psig and for air flow rates of 6 to 15 scfm, the induced water discharge flow rates varied only slightly, due to the limited range of available submergence ratios. The anticipated simulation of deep water environment, with a corresponding equivalent increase in thesubmergence ratio, proved unattainable. The pump prototype successfully transported both water and sediment (sand). Thepercent volume yield of the sediment was in an acceptable range. The pump design has been subsequently used successfully in a 4 inch configuration in a follow-on project. A computer program was written in Matlab to simulate the pump characteristics. The program output water pressures at the location of air injection which were physicallycompatible with the experimental data.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Purpose: Mismatches between pump output and venous return in a continuous-flow ventricular assist device may elicit episodes of ventricular suction. This research describes a series of in vitro experiments to characterize the operating conditions under which the EVAHEART centrifugal blood pump (Sun Medical Technology Research Corp., Nagano, Japan) can be operated with minimal concern regarding left ventricular (LV) suction. Methods: The pump was interposed into a pneumatically driven pulsatile mock circulatory system (MCS) in the ventricular apex to aorta configuration. Under varying conditions of preload, afterload, and systolic pressure, the speed of the pump was increased step-wise until suction was observed. Identification of suction was based on pump inlet pressure. Results: In the case of reduced LV systolic pressure, reduced preload (=10 mmHg), and afterload (=60 mmHg), suction was observed for speeds =2,200 rpm. However, suction did not occur at any speed (up to a maximum speed of 2,400 rpm) when preload was kept within 10-14 mmHg and afterload =80 mmHg. Although in vitro experiments cannot replace in vivo models, the results indicated that ventricular suction can be avoided if sufficient preload and afterload are maintained. Conclusion: Conditions of hypovolemia and/or hypotension may increase the risk of suction at the highest speeds, irrespective of the native ventricular systolic pressure. However, in vitro guidelines are not directly transferrable to the clinical situation; therefore, patient-specific evaluation is recommended, which can be aided by ultrasonography at various points in the course of support.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Success! At the 2005 White House Conference on Aging, three-quarters of the 1,200 national delegates voted to improve “recognition, assessment, and treatment of mental illness and depression among older Americans.” This resulted in mental health being ranked as #8 of the final 50 WHCoA policy resolutions resulting from the conference. Joining this resolution in the “top ten” were two resolutions intimately tied to hopes for addressing the mental health needs of older adults—at #6 “Support Geriatric Education and Training for Health Care Professionals, Paraprofessionals, Health Profession Students and Direct Care Workers,” and #9 “Attain Adequate Numbers of Healthcare Personnel in All Professions Who are Skilled, Culturally Competent, and Specialized in Geriatrics.”