Apical aortic blood pump preclinical assessment for long-term use: Durability test and stator topology to reduce wear in the bearing system.

This study presents an assessment for long-term use of the apical aortic blood pump (AABP), focusing on wear reduction in the bearing system. AABP is a centrifugal left ventricle assist device initially developed for bridge to transplant application. To analyze AABP performance in long-term applications, a durability test was performed.

Clinical evaluation of the Spiral Pump® after improvements to the original project in patients submitted to cardiac surgeries with cardiopulmonary bypass.

Objective: The objective of this paper is to present the results from Spiral Pump clinical trial after design modifications performed at its previous project. This pump applies axial end centrifugal hydraulic effects for blood pumping during cardiopulmonary bypass for patients under cardiac surgery.

Methods: This study was performed in 52 patients (51% males), between 20 to 80 (67±14.

In vivo evaluation of centrifugal blood pump for cardiopulmonary bypass-Spiral Pump.

The Spiral Pump (SP), a centrifugal blood pump for cardiopulmonary bypass (CPB), has been developed at the Dante Pazzanese Institute of Cardiology/Adib Jatene Foundation laboratories, with support from Sintegra Company (Pompeia, Brazil). The SP is a disposable pump with an internal rotor-a conically shaped fuse with double entrance threads. This rotor is supported by two ball bearings, attached to a stainless steel shaft fixed to the housing base.

Centrifugal blood pump for temporary ventricular assist devices with low priming and ceramic bearings.

A new model of centrifugal blood pump for temporary ventricular assist devices has been developed and evaluated. The design of the device is based on centrifugal pumping principles and the usage of ceramic bearings, resulting in a pump with reduced priming (35 ± 2 mL) that can be applied for up to 30 days. Computational fluid dynamic (CFD) analysis is an efficient tool to optimize flow path geometry, maximize hydraulic performance, and minimize shear stress, consequently decreasing hemolysis.

Cardiovascular simulator improvement: pressure versus volume loop assessment.

This article presents improvement on a physical cardiovascular simulator (PCS) system. Intraventricular pressure versus intraventricular volume (PxV) loop was obtained to evaluate performance of a pulsatile chamber mimicking the human left ventricle. PxV loop shows heart contractility and is normally used to evaluate heart performance.

A new model of centrifugal blood pump for cardiopulmonary bypass: design improvement, performance, and hemolysis tests.

A new model of blood pump for cardiopulmonary bypass (CPB) application has been developed and evaluated in our laboratories. Inside the pump housing is a spiral impeller that is conically shaped and has threads on its surface. Worm gears provide an axial motion of the blood column.

Implantable centrifugal blood pump with dual impeller and double pivot bearing system: electromechanical actuator, prototyping, and anatomical studies.

An implantable centrifugal blood pump has been developed with original features for a left ventricular assist device. This pump is part of a multicenter and international study with the objective to offer simple, affordable, and reliable devices to developing countries. Previous computational fluid dynamics investigations and wear evaluation in bearing system were performed followed by prototyping and in vitro tests.

Mock circulatory system for the evaluation of left ventricular assist devices, endoluminal prostheses, and vascular diseases.

A new digital computer mock circulatory system has been developed in order to replicate the physiologic and pathophysiologic characteristics of the human cardiovascular system. The computer performs the acquisition of pressure, flow, and temperature in an open loop system. A computer program has been developed in Labview programming environment to evaluate all these physical parameters.

A new technique to control brushless motor for blood pump application.

This article presents a back-electromotive force (BEMF)-based technique of detection for sensorless brushless direct current motor (BLDCM) drivers. The BLDCM has been chosen as the energy converter in rotary or pulsatile blood pumps that use electrical motors for pumping. However, in order to operate properly, the BLDCM driver needs to know the shaft position.

Computational fluid dynamics investigation of a centrifugal blood pump.

In the development of a ventricular assist device, computational fluid dynamics (CFD) analysis is an efficient tool to obtain the best design before making the final prototype. In this study, different designs of a centrifugal blood pump were developed to investigate flow characteristics and performance. This study assumed the blood flow as being an incompressible homogeneous Newtonian fluid.

New centrifugal blood pump with dual impeller and double pivot bearing system: wear evaluation in bearing system, performance tests, and preliminary hemolysis tests.

A new dual impeller centrifugal blood pump has been developed as a research collaboration between Baylor College of Medicine and Institute Dante Pazzanese of Cardiology for long-term left ventricle assist device (LVAD). A design feature of this new pump is a dual impeller that aims to minimize a stagnant flow pattern around the inlet port. Several different materials were tested in order to adopt a double pivot bearing design originally developed by Prof.

Endurance test on a textured diaphragm for the auxiliary total artificial heart (ATAH).

We performed an endurance test on a textured diaphragm made of polyurethane (BioSpan, The Polymer Technology Group, San Francisco, CA, U.S.A.

Improvement on the auxiliary total artificial heart (ATAH) left chamber design.

The auxiliary total artificial heart (ATAH) is an electromechanically driven artificial heart with reduced dimensions, which is able to be implanted in the right thoracic or abdominal cavities of an average human patient without removing the natural heart or the heart neurohumoral inherent control mechanism for the arterial pressure. This device uses a brushless direct current motor and a mechanical actuator (roller screw) to move two diaphragms. The ATAH's beating frequency is regulated through the change of the left preload, based on Frank-Starling's law, assisting the native heart in obtaining adequate blood flow.

Auxiliary total artificial heart: A compact electromechanical artificial heart working simultaneously with the natural heart.

Leading international institutions are designing and developing various types of ventricular assist devices (VAD) and total artificial hearts (TAH). Some of the commercially available pulsatile VADs are not readily implantable into the thoracic cavity of smaller size patients because of size limitation. The majority of the TAH dimensions requires the removal of the patients' native heart.

Flow visualization studies to improve the spiral pump design.

The spiral pump (SP) uses centrifugal and axial pumping principles simultaneously, through a conical shaped impeller with threads in its surface. Flow visualization studies were performed in critical areas of the SP. A closed circuit loop was filled with glycerin-water solution (40%).

Characteristics of a blood pump combining the centrifugal and axial pumping principles: the spiral pump.

Two well-known centrifugal and axial pumping principles are used simultaneously in a new blood pump design. Inside the pump housing is a spiral impeller, a conically shaped structure with threads on the surface. The worm gears provide an axial motion of the blood column through the threads of the central cone.

Characteristics of a Blood Pump Combining the Centrifugal and Axial Pumping Principles: The Spiral Pump.

Two well-known centrifugal and axial pumping principles are used simultaneously in a new blood pump design. Inside the pump housing is a spiral impeller, a conically shaped structure with threads on the surface. The worm gears provide an axial motion of the blood column through the threads of the central cone.

[Artificial respiration with extracorporeal membrane oxygenator in arteriovenous position without pump. Experimental study].

Purpose: To test the hypothesis of respiratory support and to study the consequent hemodynamic alterations, we performed pumpless A-V ECMO using a 1.2m2 polipropylene hollow fiber membrane oxygenator, specially adapted from conventional model utilized in routine cardiac surgery.

Methods: Two canine groups of six dogs each were studied.