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A New Method for Assessing Haemolysis in a Rotary Blood Pump Using Large Eddy Simulations (LES)

Szwast M., Moskal A., Piątkiewicz W.

Chemical and Process Engineering

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2017

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Vol. 38, nr 2

231--239

EN

The opportunity to assess haemolysis in a designed artificial heart seems to be one of the most important stages in construction. We propose a new method for assessing haemolysis level in a rotary blood pump. This method is based on CFD calculations using large eddy simulations (LES). This paper presents an approach to haemolysis estimation and shows examples of numerical simulation. Our method does not determine the value of haemolysis but allows for comparison of haemolysis levels between different artificial heart constructions.

2

Nanotechnology in artificial organ development and its application in diagnosis methodology in baroreflex sensitivity of patients with hypertension

Yambe T., Yoshizawa S., Sugita N., Tanaka A., Imachi K.

Biocybernetics and Biomedical Engineering

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2007

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Vol. 27, no. 1-2

65-70

EN

Space in the human body is so limited that nanotechnology and micromachining technology are the important for the development of the internal artificial organs. Based on the nanotechnology, various kinds of artificial organ development have been performed in Tohoku University including artificial myocardium, artificial heart, rotary blood pump, artificial esophagus, and artificial sphincter. Furthermore, automatic control algorithm for the artificial heart and assisted circulation was applied to the invention of the new diagnosis methodology for the baroreflex sensitivity of the patients with hypertension. Successful clinical application of this new invention was performed. The technical application to the large range is expectable in artificial internal-organs development.

3

Mechanically non-contact axial flow blood pump

Mitamura Y., Kido K., Yano T., Sakota D., Yozu R., Okamoto E., Murabayashi S., Nishimura I.

Biocybernetics and Biomedical Engineering

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2007

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Vol. 27, no. 1-2

139-146

EN

To overcome the drive shaft seal and bearing problem of the rotary blood pump, a hydro-dynamic bearing, a magnetic fluid seal and a brushless DC motor were employed in an axial flow pump. This enabled contact free rotation of the impeller without material wear. The axial flow pump consists of a brushless DC motor, an impeller and a guide vane. The motor rotor is directly connected to the impeller by a motor shaft. A hydrodynamic bearing is installed on the motor shaft. The motor and the hydrodynamic bearing are housed in a cylindrical casing and are waterproofed by a magnetic fluid seal. Impeller shaft displacement was measured using laser sensor. The axial and radial displacements of the shaft were less than a few micrometers for up to 8500 rpm. The shaft did not touch the housing. A flow of 5 L/min was obtained at 8000 rpm at a pressure difference of 100 mmHg. The left ventricular bypass experiment was performed in vitro. With an increase of the motor speed, the bypass flow increased, and at 7000 rpm a total bypass was obtained. The hydrodynamic bearing worked normally under variable load conditions. In conclusion, the axial flow blood pump consisting of a hydrodynamic bearing, a magnetic fluid seal and a brushless DC motor provides contact free rotation of the impeller without material wear.

4

Magnetically suspended pumps for artificial heart

Masuzawa T., Onuma H.

Biocybernetics and Biomedical Engineering

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2007

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Vol. 27, no. 1-2

133-137

EN

Durable rotary blood pumps for the artificial heart have been developed by using magnetic suspension techniques. Mechanically weak parts such as the bearings and the seal are eliminated from the device by adopting the magnetic levitated motor to the rotary blood pump. Two types of magnetically suspended rotary pumps, which have been developed at Ibaraki University, will be reported in this paper.

5

Current status of the intra-cardiac axial flow pump

Mitamura Y., Yano T., Kido K., Sakota D., Takahashi N., Mori Y., Murabayashi S., Nishimura I., Sekine K.

Biocybernetics and Biomedical Engineering

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2006

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Vol. 26, no. 1

39-44

EN

Pulsatile artificial hearts having a relatively large volume are difficult to implant in a small patient, but rotary blood pumps can be easily implanted. The objective of this study was to show the feasibility of using the Valvo-pump, an axial flow pump implanted at the heart valve position, in such cases. The Valvo-pump consists of an impeller and a motor. The motor is waterproofed with a magnetic fluid seal. A blood flow of 5 L/min was obtained at a pressure difference of 13.3 kPa at 7,500 rpm. The normalized index of hemolysis (NIH) was 2.6 times the Bio-Pump. The pump was implanted in three goats between the left ventricle and the aorta. The pump bypassed about 85% of cardiac output. The results showed that the Valvo-pump could maintain systemic circulation with an acceptable level of hemolysis.