Novel Maglev Pump With a Combined Magnetic Bearing

Onuma, Hiroyuki; Murakami, Michiko; Masuzawa, Toru

doi:10.1097/01.mat.0000151149.23519.19

Cited by 25 publications

(6 citation statements)

References 4 publications

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“…In-parallel attachment can significantly reduce pulmonary pressures and unload the right ventricle. 1-4 Thus, this is the preferred method for artificial lung attachment in lung transplant candidates with significant pulmonary hypertension and resultant RV dysfunction.…”

Section: Introductionmentioning

confidence: 99%

Hemodynamic Design Requirements for In-Series Thoracic Artificial Lung Attachment in a Model of Pulmonary Hypertension

Akay

Foucher²,

Camboni³

et al. 2012

ASAIO Journal

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Recent thoracic artificial lung (TAL) prototypes have impedances lower than the natural lung. With these devices, proximal pulmonary artery to distal pulmonary artery (PA-PA) TAL attachment may be possible in patients without right ventricular dysfunction. This study examined the relationship between pulmonary system impedance and cardiac output (CO) to create TAL design constraints. A circuit with adjustable resistance and compliance (C) was attached in a PA-PA fashion with the pulmonary circulation of seven sheep with chronic pulmonary hypertension. The pulmonary system zeroth harmonic impedance modulus (Z0) was increased by 1, 2.5, and 4 mmHg/(L/min) above baseline. At each Z0, C was set to 0, 0.34, and 2.1 mL/mmHg. The change in pulmonary system zeroth and first harmonic impedance moduli (ΔZ0 and ΔZ1), the percent change in CO (%ΔCO), and the inlet and outlet anastomoses resistances were calculated for each situation. Results indicate that ΔZ0 (p < 0.001) but not ΔZ1 (p = 0.5) had a significant effect on %ΔCO and that %ΔCO = -7.45*ΔZ0 (R2 = 0.57). Inlet and outlet anastomoses resistances averaged 0.77±0.16 and 0.10±0.19 mmHg/(L/min), respectively, and the relationship between %ΔCO and TAL resistance, RT, in mmHg/(L/min) was determined to be %ΔCO = -(7.45f)*(RT + 0.87), in which f = the fraction of CO through the TAL. Thus, newer TAL designs can limit %ΔCO to less than 10% if f < 0.75.

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Section: Introductionmentioning

confidence: 99%

Hemodynamic Design Requirements for In-Series Thoracic Artificial Lung Attachment in a Model of Pulmonary Hypertension

Akay

Foucher²,

Camboni³

et al. 2012

ASAIO Journal

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“…To exclude the problems around mechanical bearing in axial rotary blood pump or CRBP, noncontact bearing systems have been developed recently as an implantable ventricular assist device for long-term support of end-stage heart failure patients, such as magnetically levitated (MagLev) bearing system (9)(10)(11)(12)(13) or hydrodynamic levitating (HydroLev) bearing system (14)(15)(16)(17). The former is based on an active feedback control system by monitoring impeller position, while the latter passively suspends the impeller with hydrodynamic mechanism.…”

mentioning

confidence: 99%

Hemolytic Performance of a MagLev Disposable Rotary Blood Pump (MedTech Dispo): Effects of MagLev Gap Clearance and Surface Roughness

et al. 2006

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Mechanical shaft seal bearing incorporated in the centrifugal blood pumps contributes to hemolysis and thrombus formation. In addition, the problem of durability and corrosion of mechanical shaft seal bearing has been recently reported from the safety point of view. To amend the shortcomings of the blood-immersed mechanical bearings, a magnetic levitated centrifugal rotary blood pump (MedTech Dispo Model 1; Tokyo Medical and Dental University, Tokyo, Japan) has been developed for extracorporeal disposable application. In this study, the hemolytic performance of the MedTech Dispo Model 1 centrifugal blood pump system was evaluated, with special focus on the narrow blood path clearance at the magnetic bearing between rotor and stator, and on the pump housing surface roughness. A pump flow of 5 L/min against the head pressure of 100 mm Hg for 4 h was included in the hemolytic test conditions. Anticoagulated fresh porcine blood was used as a working fluid. The clearance of blood path at the magnetic bearing was in the range of 100-250 micro m. Pump housing surface roughness was controlled to be around Ra = 0.1-1.5 micro m. The lowest hemolytic results were obtained at the clearance of 250 micro m and with the polished surface (Ra = 0.1 micro m) yielding the normalized index of hemolysis (NIH) of less than 0.001 g/100 L, which was 1/5 of the Biopump BP-80 (Medtronic Inc., Minneapolis, MN, USA, and 1/4 of the BPX-80. In spite of rough surface and narrow blood path, NIH levels were less than clinically acceptable level of 0.005 g/100 L. The noncontact, levitated impeller system is useful to improve pump performance in blood environment.

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“…As a result, Equation (4) now becomes Equation (11). To form a matrix, the variables are denoted as vectors, such as in Equations ( 5)- (8).…”

Section: Magnetic Bearing Lubrication Model Developmentmentioning

confidence: 99%

“…Recent AMBs are deal with many rotordynamic issues such as vibration suppression, stability control, and condition monitoring for flexible rotor-bearing systems [7]. Using a hybrid magnetic bearing is one solution for dealing with rotordynamic and power loss issues [8,9]. There has also been research on magnetic bearing fault detection and diagnosis for reducing the rotor instability [10].…”

Section: Introductionmentioning

confidence: 99%

Instability Study of Magnetic Journal Bearing under S-CO2 Condition

2021

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A supercritical CO2 (S-CO2)-cooled Brayton cycle is under development for distributed power applications for remote regions. In order to successfully develop it, issues of controlling shaft levitation with bearings have to be solved. From several studies, magnetic bearings have been suggested for reliable levitation performance with reduced cost and complexity. However, several studies on magnetic bearing show that instability issues under high-pressure fluid and high-speed operating conditions may exist. The purpose of this research is to provide background for understanding the instability of magnetic bearings under S-CO2 conditions and propose functional requirements of the magnetic bearing. Thus, the rotating shaft with magnetic bearings operating under high pressure fluid was first analyzed. To test the theory, a magnetic bearing test rig was constructed. By comparing experimental data to the analysis results, the analysis results were verified. Therefore, the analysis results can be used for predicting instability in the future and can contribute to the development of better magnetic bearing controllers.

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Novel Maglev Pump With a Combined Magnetic Bearing

Cited by 25 publications

References 4 publications

Hemodynamic Design Requirements for In-Series Thoracic Artificial Lung Attachment in a Model of Pulmonary Hypertension

Hemodynamic Design Requirements for In-Series Thoracic Artificial Lung Attachment in a Model of Pulmonary Hypertension

Hemolytic Performance of a MagLev Disposable Rotary Blood Pump (MedTech Dispo): Effects of MagLev Gap Clearance and Surface Roughness

Instability Study of Magnetic Journal Bearing under S-CO2 Condition

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