Biomedical subjects

Curt Tribble

Publications and source records attributed to Curt Tribble.

4 recordsLinked to original sources

PubMed2003

An advanced physiological controller design for a left ventricular assist device to prevent left ventricular collapse.

A continuous flow left ventricle assist device (LVAD), which is mainly composed of a continuous flow blood pump and a physiological controller, has only one control input, the rotational speed of the pump, but at least three performance criteria to meet. The challenge for the physiological controller of a long-term continuous flow LVAD is the adaptability to different cardiovascular loading situations and the ability to handle systemic and parametric uncertainties with only one control input. The physiological LVAD controller presented in this article exhibits good performance in terms of the three performance criteria in different physiological loading conditions, such as disturbance, resting, and moderate exercise, for a patient with congestive heart failure. The collapse of the left ventricle, which is an inherent problem for a continuous flow LVAD, has been prevented because of the control algorithm design.

Computer Simulation↗

PubMed2002

The establishment of a surgical interest society for medical students.

With the advent of initiatives by many medical schools to attract students to generalist fields, the curriculum at these institutions has undergone substantial change. In many instances these changes include the abbreviation of exposure to specialty fields such as surgery. Consequently, the exposure of medical students to the surgical discipline and surgeons may be decreased at these institutions. These changes are particularly concerning in light of studies that suggest that these important interactions are the primary influences that lead students to pursue a career in specific fields. It is also interesting to note that these trends in decreasing exposure to surgical fields seem to correlate with recent increases in the number of unfilled categorical residency positions in general surgery. This article focuses on the experiences of a group of students and faculty mentors at the University of Virginia School of Medicine as they set about creating an extracurricular opportunity for students to explore interests in surgical fields. We shall present the thoughts and rationale we used in planning the establishment of our own student surgical interest society, as well as the manner in which we ultimately went about constructing this organization. It is our hope that this information will provide some ideas for the creation of similar societies at other institutions.

Career Mobility↗

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Computational design and experimental testing of a novel axial flow LVAD.

Thousands of cardiac failure patients per year in the United States could benefit from long-term mechanical circulatory support as destination therapy. To provide an improvement over currently available devices, we have designed a fully implantable axial-flow ventricular assist device with a magnetically levitated impeller (LEV-VAD). In contrast to currently available devices, the LEV-VAD has an unobstructed blood flow path and no secondary flow regions, generating substantially less retrograde and stagnant flow. The pump design included the extensive use of conventional pump design equations and computational fluid dynamics (CFD) modeling for predicting pressure-flow curves, hydraulic efficiencies, scalar fluid stress levels, exposure times to such stress, and axial fluid forces exerted on the impeller for the suspension design. Flow performance testing was completed on a plastic prototype of the LEV-VAD for comparison with the CFD predictions. Animal fit trials were completed to determine optimum pump location and cannulae configuration for future acute and long-term animal implantations, providing additional insight into the LEV-VAD configuration and implantability. Per the CFD results, the LEV-VAD produces 6 l/min and 100 mm Hg at a rotational speed of approximately 6300 rpm for steady flow conditions. The pressure-flow performance predictions demonstrated the VAD's ability to deliver adequate flow over physiologic pressures for reasonable rotational speeds with best efficiency points ranging from 25% to 30%. The CFD numerical estimations generally agree within 10% of the experimental measurements over the entire range of rotational speeds tested. Animal fit trials revealed that the LEV-VAD's size and configuration were adequate, requiring no alterations to cannulae configurations for future animal testing. These acceptable performance results for LEV-VAD design support proceeding with manufacturing of a prototype for extensive mock loop and initial acute animal testing.

Animals↗