Artificial Heart Pump Research Articles

Entropy Analysis in Magnetized Blood-Based Hybrid Nanofluid Flow via Parallel Disks

Magnetized hybrid nanofluid combined with ferrite and silver in a blood-based liquid presents their vital role in several aspects such as artificial heart pumping system, drug delivery process, the flow of blood in the artery, etc. This is because the high heat transportation rate of the nanofluid is caused by the inclusion of nanoparticles. The current investigation is based on the characteristic of particle concentration comprised of Fe3O4 and Ag in the base liquid blood that passed in between two infinite parallel disks filled with porous matrix. The electrically conducting fluid associated to maximum of 1.5% of volume concentration from each of the solid particles affects the flow phenomena. However, the impact of thermal radiation vis-à-vis the heat dissipation provides efficient heat transport properties with the inclusion of the effective thermal conductivity assumed from the Hamilton-Crosser model. The proposed conductivity model describes the role of particle shapes on the enhanced thermal properties. Further, numerical treatment is obtained for the transformed designed problem following similarity rules that are used for the conversion of the governing equations into their non-dimensional form. The computation of various flow profiles leads to get the entropy generation due to the irreversibility processes. Along with the fluid velocity and temperature distributions, the study is carried out for the entropy as well as the computation of Bejan number and afterwards the simulation of the shear and heat transportation rate are also depicted graphically. The main finding of the proposed study is that solid particle concentrations have a substantial impact to increasing fluid velocity in magnitude, resulting in a narrower wall thickness at both channel walls. Thermal radiation was shown to be more effective at increasing entropy generation and Bejan value.

Thrombus Detection in the Artificial Heart Pump Based on Electrical Impedance Spectroscopy

Thrombus Detection in the Artificial Heart Pump Based on Electrical Impedance Spectroscopy

Enhanced Anticoagulation of Hierarchy Liquid Infused Surfaces in Blood Flow.

Liquid infused surfaces (LIS) hold remarkable potential in anticoagulation. However, liquid loss of LIS in the bloodstream remains a challenge toward its clinical application. Here, micronano hierarchy structures are obtained on the titanium alloy substrate by regulating the microspheres' distribution. When the gap between the microspheres is smaller than the diameter of the red blood cell (RBC), the LIS is more stable under the blood wash and presents a better anticoagulation performance. The proper interval is found to prevent the RBCs from entering the gap and remove the liquid on the surface. The retained thickness of the liquid film is measured by the atomic force microscopy (AFM) technique. The LIS is applied on the front guide vane of an artificial heart pump and exhibits significant improvement on anticoagulation in the blood circulation in vitro for 25 h. The techniques and findings can be used to optimize the anticoagulation performance of LIS-related biomedical implant devices.

Human fitting of pediatric and infant continuous-flow total artificial heart: visual and virtual assessment.

This study aimed to determine the fit of two small-sized (pediatric and infant) continuous-flow total artificial heart pumps (CFTAHs) in congenital heart surgery patients. This study was approved by Cleveland Clinic Institutional Review Board. Pediatric cardiac surgery patients (n = 40) were evaluated for anatomical and virtual device fitting (3D-printed models of pediatric [P-CFTAH] and infant [I-CFTAH] models). The virtual sub-study consisted of analysis of preoperative thoracic radiographs and computed tomography (n = 3; 4.2, 5.3, and 10.2 kg) imaging data. P-CFTAH pump fit in 21 out of 40 patients (fit group, 52.5%) but did not fit in 19 patients (non-fit group, 47.5%). I-CFTAH pump fit all of the 33 patients evaluated. There were critical differences due to dimensional variation (p < 0.0001) for the P-CFTAH, such as body weight (BW), height (Ht), and body surface area (BSA). The cutoff values were: BW: 5.71 kg, Ht: 59.0 cm, BSA: 0.31 m2. These cutoff values were additionally confirmed to be optimal by CT imaging. This study demonstrated the range of proper fit for the P-CFTAH and I-CFTAH in congenital heart disease patients. These data suggest the feasibility of both devices for fit in the small-patient population.

A Physiological Control for Artificial Heart Pump based on Adaptive Regulation of Heart Rate and the improved BAS Algorithm Optimization

In order to solve the problem that the traditional artificial heart pump has poor dynamic bionic performance and cannot respond to blood perfusion in real time according to the patient’s state, this paper proposes a new physiological control method based on adaptive adjustment of heart rate. Firstly, a coupled model of the cardiovascular circulatory system and artificial heart pump was established, and the correctness of the model is verified by hemodynamic simulation. Secondly, according to the model-free adaptive control theory, the artificial heart pump physiological control strategy for adaptive regulation of heart rate is designed, including pseudo partial derivative estimation algorithm and adaptive control law. Then, the parameters of the adaptive controller are optimized by the improved beetle antennae search algorithm. Finally, the auxiliary effect and dynamic performance of the adaptive control strategy are studied by numerical methods. The results show that the physiological control method based on adaptive regulation of heart rate realizes the adaptive modulation of heart rate and blood flow, which can meet the needs of blood perfusion in different states and help to promote the recovery of damaged heart.

Mock circulatory loop applications for testing cardiovascular assist devices and in vitro studies.

The mock circulatory loop (MCL) is an in vitro experimental system that can provide continuous pulsatile flows and simulate different physiological or pathological parameters of the human circulation system. It is of great significance for testing cardiovascular assist device (CAD), which is a type of clinical instrument used to treat cardiovascular disease and alleviate the dilemma of insufficient donor hearts. The MCL installed with different types of CADs can simulate specific conditions of clinical surgery for evaluating the effectiveness and reliability of those CADs under the repeated performance tests and reliability tests. Also, patient-specific cardiovascular models can be employed in the circulation of MCL for targeted pathological study associated with hemodynamics. Therefore, The MCL system has various combinations of different functional units according to its richful applications, which are comprehensively reviewed in the current work. Four types of CADs including prosthetic heart valve (PHV), ventricular assist device (VAD), total artificial heart (TAH) and intra-aortic balloon pump (IABP) applied in MCL experiments are documented and compared in detail. Moreover, MCLs with more complicated structures for achieving advanced functions are further introduced, such as MCL for the pediatric application, MCL with anatomical phantoms and MCL synchronizing multiple circulation systems. By reviewing the constructions and functions of available MCLs, the features of MCLs for different applications are summarized, and directions of developing the MCLs are suggested.

A Physiological Control Method Based on SMC and GAPSO for Artificial Heart Pumps to Maintain Pulsatility and Avoid Regurgitation and Suction

A Physiological Control Method Based on SMC and GAPSO for Artificial Heart Pumps to Maintain Pulsatility and Avoid Regurgitation and Suction

Sensorless control of the BPMSM for artificial heart based on the improved SMO, the improved HFI and the GAPSO algorithm

BackgroundIncrease in volume in the bearingless permanent magnet slice motor (BPMSM) control system for artificial hearts is the major problem in the existing works. ObjectiveA sensorless control method of the BPMSM for the artificial heart is proposed in the study based on an improved sliding mode observer (SMO) and improved high-frequency injection method. Also, a full-speed rotor position detection method combining the high-frequency injection (FHI) method and sliding mode observer is designed. MethodologyIn this method, an improved high-frequency injection method was designed in the low-speed domain, and an improved sliding-mode observer was designed in the medium–high-speed domain. Besides, the speed domain switching method based on the genetic particle swarm optimization (GAPSO) algorithm was adopted at the critical point of the low-speed domain and the medium and high-speed domain to realize the smooth switching between different estimation methods, and then realize the sensorless control of the rotor in the full speed domain. Secondly, the simulation study by Simulink was used to compare the detection effects of the BPMSM rotor position and speed of the artificial heart pump under different methods are compared in this work. ResultThe results show that the speed estimation value and rotor position estimation value of the new method in this paper were closer to the actual value, the position estimation error is 3%, and the speed estimation error was within 1.5%. Further, the experimental study was carried out on the principal prototype of the sensorless control part of the artificial heart to verify the effectiveness of the proposed method. ConclusionThe method proposed in this paper has certain generality in the field of motor sensorless control technology, and has important reference value for researchers in this field.

Numerical study on the performance of centrifugal blood pump with superhydrophobic surface.

In order to reduce the blood damage of an artificial heart pump and optimize its hydraulic performance, a centrifugal blood pump with superhydrophobic characteristics is proposed in this study. To study the influence of superhydrophobic surface characteristics on the performance of centrifugal blood pumps, the Navier slip model is used to simulate the slip characteristics of superhydrophobic surfaces, which is realized by the user defined function of ANSYS fluent. The user defined functions with different values of slip length are verified by two benchmark solutions of laminar flow and turbulence in the pipeline. The blood pump model adopts the designed centrifugal blood pump, and its head, hydraulic efficiency and hemolysis index are calculated. The Navier slip boundary condition (a constant slip-length of 50 μm) is applied to the walls of the blood pump impeller and a volute at different positions, and the influence of the superhydrophobic surface on the performance of the blood pump at the design point Q = 6 L/min was compared and analyzed. The results show that the centrifugal blood pump model used in this paper has good blood compatibility and meets the design requirements; the superhydrophobic surface can significantly reduce the scalar shear stress in the blood pump. At the design point, when the slip length is 50 μm, the mass-average scalar shear stress in the impeller area and the volute area reduction rate is about 5.9%, the hydraulic efficiency growth rate is about 3.8%, the hemolysis index reduction rate is about 18.4%, and the pressure head changes little with a growth rate of 0.3%. Centrifugal blood pumps with superhydrophobic surfaces can improve the efficiency of blood pumps and reduce hemolysis. Based on these encouraging results, vitro investigations for actual blood damage would be practicable.

Eccentricity Effect on Radial Forces of Bearingless BLDC Motor: Study and Analysis

The bearingless BLDC motor gathers all advantages of the BLDC motor and bearingless machine, and this motor is extensively used in blood and artificial heart pumps. In a bearingless BLDC motor, there are two sets of windings, the main winding, responsible for producing the motor torque, and the suspension winding, which keeps the rotor in the center without any contact with the stator. Generally, the suspension system is responsible for the generation of the suspension forces to cancel the pull-out forces (radial forces), which strongly depends on the accurate evaluation of radial forces distribution at different operating conditions. In this paper, a mathematical model based on the finite element method is used to calculate and analyze the radial force of a bearingless blood pump BLDC motor using Ansys/Maxwell. Based on Maxwell equations, the normal and tangential components of the airgap flux density is determined and used to calculate the radial force, magnitude, and direction. In addition, different cases of rotor displacement under eccentricity conditions are covered. The relation between the rotor displacement and radial force is analyzed, accounting for the displacement direction. Finally, the results are analyzed and discussed.

Particle swarm optimization based interval type 2 fuzzy logic control for motor rotor position control of artificial heart pump

Artificial heart pump (AHP) is employed to replace the native damaged heart and perform its functions. Bearingless brushless DC (BBLDC) motors are used for the implementation of the AHP. BBLDC motor is a highly nonlinear model with uncertainties and its mathematical model is hard to be found accurately. In this paper, BBLDC motor is simulated. Proportional plus integral (PI) controller is proposed to control the rotor suspension current. Furthermore, a type 2 proportional plus integral plus derivative-like fuzzy logic controller (T2 PID-Like FLC) is proposed to control the motor rotor (x, y) positions. Particle swarm optimization (PSO) technique is employed to find the best controller scaling factors and to optimize the controller inputs membership functions distribution within its universe of discourse. Simulation results showed enhancement in levitating the rotor to the required position, when using T2 PID-like FLC as compared with using type 1 PID-like fuzzy logic controller. The enhancement is measured using integral of absolute error (IAE) as a cost function to achieve 64.18% and 81.81% in the x and y axes respectively. The Performance of the motor is enhanced by 20%, which decreases the rotor oscillation and increases the ability to withstand the system disturbances and nonlinearity

Optimal Adaptive Magnetic Suspension Control of Rotary Impeller for Artificial Heart Pump

This study presents the development of adaptive control algorithm based on backstepping methodology for magnetic suspension of rotating impeller for artificial heart pump subjected to external disturbance. The magnetic bearing system for pump impeller consists of two pairs of magnetic coils, one pair at each end of the impeller. These coils are injected by the required control currents to produce the necessary magnetic field for correctly suspending the axial motions of impeller in both horizontal and vertical planes. The adaptive backstepping control algorithm has been established by following a rigorous Lyapunov-based stability analysis, to prove the asymptotic convergence of errors in the presence of unknown external uncertainty. The setting of design parameters for the adaptive controller is another issue which has been solved by suggesting particle swarm optimization to tune the design parameters of adaptive controller toward optimal performance. The computer simulation showed that the optimal adaptive controller could successfully and quickly suspend the impeller for both regulation and tracking scenarios irrespective to all initial deviations of rotating shaft under exerted disturbance. Also, the developed adaptive laws of proposed adaptive controller could estimate the uncertainty without drift, which ensures the asymptotic convergence of errors.

Optimization analysis for blades of artificial heart pump based on CFD

In this paper, computational fluid dynamics is used to simulate and analyse the flow field of a centrifugal artificial heart pump. First, the structural parameters of the centrifugal blood pump are initially determined, and the three-dimensional model of the flow field is established. The blood supply head of the pump is calculated based on the simulation results. The head of the centrifugal blood pump is 124.31mmHg under the design conditions (rotating speed is 2400rpm, flow rate is 6L/min), which meets the blood supply requirement of the heart pump. Then, by changing the blade profile length and blade shape, the performance of the centrifugal blood pump can be improved. The standard hemolysis index of the improved centrifugal blood pump dropped from 0.0508 to 0.0417, and its head is 119.65mmHg. It indicates that while reducing the destruction of blood cells by the heart pump, the requirement of blood supply head can still be met. The simulation results of this study can provide references for the design of centrifugal blood pump blades.

5 nm-scale surface evenness movement measurement method based on the electron spin in diamond

The motion of a magnetic levitation structure can lead to low accuracy for magnetically suspended control moment gyros (MSCMG), artificial heart pumps or high precision stable platforms. Measuring this motion is important in orbital navigation and precision measurement technologies, but current methods are unable to measure it with high accuracy under a strong magnetic field around the magnetic levitation structure. Here, we present a method in which nitrogen–vacancy (NV) centers in diamond have been used as a sensor to detect the movement of the magnetic levitation structure. The NV quantum sensors probe the electric field around the suspension magnet induced by the magnet fluctuations. Based on the high sensitivity of 0.3 nT (√Hz)−1, the resolution of motion was about 5 nm. Also, the dynamic movement of the magnetic levitation system has been recorded in real-time with a potential resolution of ∼pm as the magnetic field sensitivity of NV center was improved to ∼pT. Our method offers a novel route to measure and feedback control the magnetic levitation system for MSCMGs in satellite attitude or for magnetic pumps in artificial heart applications.

An integral sliding mode control for the magnetic levitation system based on backstepping approach

Due to their reduced maintenance costs, increased power efficiency and reduced power consumption, the Magnetic Levitation (Maglev) system make a significant contribution to the industrial application. Maglev’s production of electricity (e.g. wind turbines), maglev trains and medical devices (e.g. artificial heart pump magnetically suspended) are typical applications. This paper suggests designing a nonlinear control for the Maglev system model which represented by a third-order model consists of the mechanical (ball position and velocity) and electrical (the current) subsystems. The controller is designed utilizing the Integral Sliding Mode Control (ISMC) and based on the Backstepping approach. The tracking accuracy of the ball position to the desired reference is determined by computing the ultimate boundedness as a function to the controller parameters and that using the Lyapunov function. The numerical simulation results showed the robustness and the efficiency of the proposed controller where the tracking error limited by the computed bound.

Right Ventricular Device HeartWare Implant to the Right Atrium with Fixation to the Chest Wall in Patient with Biventricular Support.

Right Ventricular Device HeartWare Implant to the Right Atrium with Fixation to the Chest Wall in Patient with Biventricular Support.

Artificial Heart Pumps Move into Space

Artificial Heart Pumps Move into Space

Development and Application of Permanent Magnet Motor and Its Control in the Field of Artificial Blood Pump

Permanent magnet motor has been widely used in the field of artificial heart pump due to its high power density, high stability and easy control. In this paper, the development history and research progress of permanent magnet motor for blood pump were described. Firstly, the motors were classified according to their structures and application scenarios. And then, the measures taken by different types of motors to meet the corresponding performance requirements were introduced, and the specific application cases were given. After that, commonly used control algorithms of these motors were enumerated. What's more, the advantages and disadvantages of the control algorithms and their application emphasis were carefully explained. Finally, the paper was summarized in short.

Bionic women and men: Heart failure and an artificial heart pump

Bionic women and men: Heart failure and an artificial heart pump

Numerical simulation of an immersed rotating structure in fluid for hemodynamic applications

In this paper, numerical simulation of a hemodynamic fluid-structure interaction (FSI) problem with an immersed rotating structure is carried out. A dynamic FSI problem involving a rotational elastic solid, which is modeled by the incompressible shear stress transport (SST) k–ω turbulence model in the fluid domain and by a co-rotational linearized St. Venant–Kirchhoff model in the structure domain, is studied and applied to a type of artificial heart pump. A monolithic arbitrary Lagrangian–Eulerian mixed finite element method, which is modified to adapt to the interaction between fluid and an immersed rotating structure, is employed to discretize the coupled FSI system. The Newton's linearization and the streamline-upwind/Petrov–Galerkin (SUPG) stabilization are employed to overcome strong nonlinearity and dominant convection effects, respectively. Numerical validations are preformed and compared with a commercial CFD software. This paper is an extension to our recent conference paper [1].