New Linear Motor Concepts for Artificial Hearts

Hemocompatibility of blood pumps is a crucial parameter that has to be ensured prior to in vivo testing. In contrast to rotary blood pumps, a standard for testing a pulsatile total artificial heart (TAH) has not yet been established. Therefore, a new mock circulation loop was designed to investigate hemolysis in the left ventricle of the ReinHeart TAH. Its main features are a high hemocompatibility, physiological conditions, a low priming volume, and the conduction of blood through a closed tubing system. The mock circulation loop consists of a noninvasive pressure chamber, an aortic compliance chamber, and an atrium directly connected to the ventricle. As a control pump, the clinically approved Medos-HIA ventricular assist device (VAD) was used. The pumps were operated at 120 beats per minute with an aortic pressure of 120 to 80 mm Hg and a mean atrial pressure of 10 mm Hg, generating an output flow of about 5 L/min. Heparinized porcine blood was used. A series of six identical tests were performed. A test method was established that is comparable to ASTM F 1841, which is standard practice for the assessment of hemolysis in continuous-flow blood pumps. The average normalized index of hemolysis (NIH) values of the VAD and the ReinHeart TAH were 0.018 g/100 L and 0.03 g/100 L, respectively. The standard deviation of the NIH was 0.0033 for the VAD and 0.0034 for the TAH. Furthermore, a single test with a BPX-80 Bio-Pump was performed to verify that the hemolysis induced by the mock circulation loop was negligible. The performed tests showed a good reproducibility and statistical significance. The mock circulation loop and test protocol developed in this study are valid methods to investigate the hemolysis induced by a pulsatile blood pump.

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“…Finocchiaro et al. describe its actuator with a moving coil in between two permanent magnets. As presented in Fig.…”

Section: Methodsmentioning

confidence: 99%

Mock Circulation Loop to Investigate Hemolysis in a Pulsatile Total Artificial Heart

et al. 2015

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“…Two surgical approaches have been popularized to access the chest of large animals: full median sternotomy and thoracotomy (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). Two surgical approaches have been popularized to access the chest of large animals: full median sternotomy and thoracotomy (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14).…”

Section: Resultsmentioning

confidence: 99%

“…For this reason, optimized implantation techniques have been elaborated by various teams to ensure that the implantation procedure is safe and reliable, yielding the best postoperative outcome achievable with a given device. Two surgical approaches have been popularized to access the chest of large animals: full median sternotomy and thoracotomy (1)(2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14). The thoracotomy approach has become the most used surgical access technique for mechanical circulatory device implantation.…”

Section: Resultsmentioning

confidence: 99%

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Investigation of the Durability of a Diaphragm for a Total Artificial Heart

Graf¹,

Rossbroich²,

Finocchiaro³

et al. 2015

Artificial Organs

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One of the most critical components regarding the durability of the ReinHeart total artificial heart (TAH) is its biocompatible diaphragm, which separates the drive unit from the ventricles. Hence, a durability tester was designed to investigate its required 5-year lifetime. The aim of this study was to prove the validity of accelerated testing of the polyurethane diaphragm. The durability tester allows simultaneous testing of 12 diaphragms and mimics physiological conditions. To accelerate the time of testing, it operates with an increased speed at a frequency of 8 Hz. To prove the correctness of this acceleration, a servo-hydraulic testing machine was used to study the effect of different frequencies and their corresponding loads. Thereby the viscoelastic behavior of the polyurethane was investigated. Additionally, high-speed video measurements were performed. The force against frequency and the high-speed video measurements showed constant behavior. In the range of 1-10 Hz, the maximum resulting forces varied by 3%, and the diaphragm movement was identical. Frequencies below 10 Hz allow a valid statement of the diaphragm's mechanical durability. Viscoelasticity of the polyurethane in the considered frequency-range is negligible. The accelerated durability test is applicable to polyurethane diaphragms, and the results are applicable to TAH use. The reliability of the diaphragm for a lifetime of 5 years was found to be 80% with a confidence of 62%.

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“…The AH drive device must meet a variety of requirements, such as small size, high reliability, high power density and light weight 2 . Existing electric drive based AHs employ rotary blood pumps but suffer from damage to blood cells 3 . Linear AH motors were proposed to solve this problem, but its force density was relatively poor 4 .…”

Section: Introductionmentioning

confidence: 99%

Design and analysis of a field modulated magnetic screw for artificial heart

Ling

Wang

et al. 2017

AIP Advances

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This paper proposes a new electromechanical energy conversion system, called Field Modulated Magnetic Screw (FMMS) as a high force density linear actuator for artificial heart. This device is based on the concept of magnetic screw and linear magnetic gear. The proposed FMMS consists of three parts with the outer and inner carrying the radially magnetized helically permanent-magnet (PM), and the intermediate having a set of helically ferromagnetic pole pieces, which modulate the magnetic fields produced by the PMs. The configuration of the newly designed FMMS is presented and its electromagnetic performances are analyzed by using the finite-element analysis, verifying the advantages of the proposed structure.

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New Linear Motor Concepts for Artificial Hearts

Cited by 31 publications

References 6 publications

Mock Circulation Loop to Investigate Hemolysis in a Pulsatile Total Artificial Heart

Mock Circulation Loop to Investigate Hemolysis in a Pulsatile Total Artificial Heart

Investigation of the Durability of a Diaphragm for a Total Artificial Heart

Design and analysis of a field modulated magnetic screw for artificial heart

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