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8 results on '"Patrick Borchers"'

1. Electrodynamics of Axial-Flow Rotary Blood Pumps

Author

Igor V. Nesterenko, Alexander A. Pugovkin, Steffen Leonhardt, Marian Walter, Patrick Borchers, Aleksandr Markov, Jamshid H. Karimov, Sergey V. Selishchev, and Dmitry V. Telyshev

Subjects
Axial-flow, back electromotive force, electrodynamics, permanent magnet rotor, rotary blood pump, sinusoidal waveform, Electrical engineering. Electronics. Nuclear engineering, TK1-9971
Abstract

In this work, electric machine of implantable rotary blood pumps (RBPs) of axial-flow type was theoretically investigated. Electromagnetic coupling of rotor and stator in axial-flow RBPs was described with the Maxwell’s equations of the classical electrodynamics given quasi-magnetostatic approximation of electromagnetic field in the simplified model consisting of permanent magnet and conductive loop rotating in free space with one spatial degree of freedom. Additionally, relative field error, created by the neglect of geometric deviations introduced through manufacturing tolerances, was estimated for a typical axial-flow RBP. Upper limit of error introduced by the simplifications was estimated less than 0.2 %, leading to the finite accuracy of the description and clearly determining the influence on the control signal. Based on the presented description and additional engineering considerations, the electric machine of axial-flow RBPs was defined as a three-phase non-salient pole synchronous machine with a permanent magnet rotor. Two key features were shown: a) unlike the conventional electric motors, signal of back electromotive force tends to be a sinusoidal waveform in any construction of axial-flow RBP with significant non-magnetic gap; b) the optimal waveform of control signal in this case is sinusoidal. Initial design and control parameters of the electric machine in axial-flow RBPs can be accurately determined with presented theoretical description. Based on the description, control system of an axial-flow RBP with the optimal waveform of control signal can be developed.

Published
2021
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2. In vitro validation of a non-invasive continuous blood pressure measurement method for the perioperative application

Author

Paul Geus, Daniel Laidig, Patrick Borchers, Thomas Seel, Johanna Stettin, and Ulrich Kertzscher

Subjects
blood pressure measurement, non-invasive, Biomedical Engineering, iterative learning control, Medicine, perioperative
Abstract

Hypotensive periods during surgery lead to an increase in postoperative complications. To further avoid the adverse events associated with the invasive measurement of the blood pressure, a perioperative, continuous, non-invasive blood pressure measurement method was developed. The precision of the method was tested for different mean pressure values and different thicknesses of the tissue model using a specifically designed and validated simulator that has the characteristics of the lower arm. The mean pressure difference between the pressure determined by the proposed method and simulated blood pressure from the simulator was 3.93 mmHg (±4.75 mmHg) for the systole and 4.89 mmHg (±6.10 mmHg) for the diastole. The results showed that the method can be a promising alternative to invasive blood pressure measurement methods.

Published
2021

3. Comparison of the Hemocompatibility of an Axial and a Centrifugal Left Ventricular Assist Device in an In Vitro Test Circuit

Author

Patrick Borchers, Patrick Winnersbach, Sandra Kraemer, Christian Beckers, Eva Buhl, Steffen Leonhardt, Rolf Rossaint, Marian Walter, Thomas Breuer, and Christian Bleilevens

Subjects
left ventricular assist device, in vitro test circuit, Sputnik, HeartMate 3, hemocompatibility, hemolysis, coagulation, platelet activation, extracellular vesicles, General Medicine, ddc:610
Abstract

Journal of Clinical Medicine 11(12), 3431 (2022). doi:10.3390/jcm11123431, Published by MDPI, Basel

Published
2022

4. Flow profile generation for a left ventricular assist device using iterative learning control

Author

Patrick Borchers, Marian Walter, Steffen Leonhardt, Dmitry Telyshev, and Alexander Pugovkin

Subjects
mock circulatory loop, ventricular assists device, pid control, ddc:570, Biomedical Engineering, iterative learning control, Medicine
Abstract

55th Annual Meeting of the German Society of Biomedical Engineering, BMT 2021, online, 5 Oct 2021 - 7 Oct 2021; Current directions in biomedical engineering 7(2), 279-282 (2021). doi:10.1515/cdbme-2021-2071 special issue: "Proceedings of the 55th Annual Meeting of the German Society of Biomedical Engineering (5 ��� 7 October 2021, Hannover)", Published by De Gruyter, Berlin

Published
2021
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5. International Conflict of Laws for the Third Millennium: Essays in Honor of Friedrich K. Juenger

Author

Patrick Borchers, Joachim Zekoll, Patrick Borchers, and Joachim Zekoll

Subjects
Conflict of laws
Abstract

Few scholars have contributed more to this new and important view of conflict of laws than Professor Friedrich K. Juenger of the University of California, Davis. In this Festschrift in his honor, leading scholars from North America and Europe bring their vision and expertise to bear on this core issue of private international law, reflecting the multiple facets of a fundamental doctrine as it adapts to new and unprecedented global realities. Published under the Transnational Publishers imprint.

Published
2021

6. Conflicts in a Nutshell

Author

Patrick Borchers and Patrick Borchers

Subjects
Conflict of laws--United States
Abstract

Develop perspective on the conflicts of law arena with Borchers's broad vantage point. Topics covered include issues involving domicile; jurisdiction; adjudication; statute of limitations; foreign law; contract and business cases; torts;'renvoi'; Erie Doctrine; judgments; and family (marriage, dissolution of marriage, property incidents, and custody). Use Conflicts in a Nutshell as an introduction and review tool for students or as a quick refresher and reference tool for lawyers.

Published
2015

7. Hay, Borchers and Symeonides' Conflict of Laws, 5th (Hornbook Series)

Author

Peter Hay, Patrick Borchers, Symeon Symeonides, Peter Hay, Patrick Borchers, and Symeon Symeonides

Subjects
Conflict of laws--United States
Abstract

This authoritative text covers jurisdiction and interstate and international private litigation in torts, contracts, business planning, family law (marriage, same-sex relationships, property rights, support, child custody), property, succession and estate administration, and the recognition of sister-state and foreign judgments. The text examines in depth the development and current state of approaches to choice of law. It also addresses issues of jurisdiction and applicable law in private litigation in federal court.

Published
2010

8. Conflicts in a Nutshell, 3d

Author

David Siegel, Patrick Borchers, David Siegel, and Patrick Borchers

Subjects
Conflict of laws--United States
Abstract

Develop perspective on the conflicts of law arena with Siegel's broad vantage point. Topics covered include issues involving domicile; jurisdiction; adjudication; statute of limitations; foreign law; contract and business cases; torts;'renvoi'; Erie Doctrine; judgments; and family (marriage, dissolution of marriage, property incidents, and custody). Use Siegel's Conflicts in a Nutshell as an introduction and review tool for students or as a quick refresher and reference tool for lawyers.

Published
2005

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