TY  - JOUR
A1  - Brockhaus, Moritz K.
A1  - Behbahani, Mehdi
A1  - Muris, Farina
A1  - Jansen, Sebastian V.
A1  - Schmitz-Rode, Thomas
A1  - Steinseifer, Ulrich
A1  - Clauser, Johanna C.
T1  - In vitro thrombogenicity testing of pulsatile mechanical circulatory support systems: Design and proof-of-concept
JF  - Artificial Organs
N2  - Thrombogenic complications are a main issue in mechanical circulatory support (MCS). There is no validated in vitro method available to quantitatively assess the thrombogenic performance of pulsatile MCS devices under realistic hemodynamic conditions. The aim of this study is to propose a method to evaluate the thrombogenic potential of new designs without the use of complex in-vivo trials. This study presents a novel in vitro method for reproducible thrombogenicity testing of pulsatile MCS systems using low molecular weight heparinized porcine blood. Blood parameters are continuously measured with full blood thromboelastometry (ROTEM; EXTEM, FIBTEM and a custom-made analysis HEPNATEM). Thrombus formation is optically observed after four hours of testing. The results of three experiments are presented each with two parallel loops. The area of thrombus formation inside the MCS device was reproducible. The implantation of a filter inside the loop catches embolizing thrombi without a measurable increase of platelet activation, allowing conclusions of the place of origin of thrombi inside the device. EXTEM and FIBTEM parameters such as clotting velocity (α) and maximum clot firmness (MCF) show a total decrease by around 6% with a characteristic kink after 180 minutes. HEPNATEM α and MCF rise within the first 180 minutes indicate a continuously increasing activation level of coagulation. After 180 minutes, the consumption of clotting factors prevails, resulting in a decrease of α and MCF. With the designed mock loop and the presented protocol we are able to identify thrombogenic hot spots inside a pulsatile pump and characterize their thrombogenic potential.
Y1  - 2021
U6  - https://doi.org/10.1111/aor.14046
SN  - 1525-1594
VL  - 45
IS  - 12
SP  - 1513
EP  - 1521
PB  - Wiley
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Stäudle, Benjamin
A1  - Seynnes, Olivier
A1  - Laps, Guido
A1  - Göll, Fabian
A1  - Brüggemann, Gert-Peter
A1  - Albracht, Kirsten
T1  - Recovery from achilles tendon repair: a combination of Postsurgery Outcomes and Insufficient remodeling of muscle and tendon
JF  - Medicine & Science in Sports & Exercise
N2  - Achilles tendon rupture (ATR) patients have persistent functional deficits in the triceps surae muscle–tendon unit (MTU). The complex remodeling of the MTU accompanying these deficits remains poorly understood. The purpose of the present study was to associate in vivo and in silico data to investigate the relations between changes inMTU properties and strength deficits inATR patients. Methods: Elevenmale subjects who had undergone surgical repair of complete unilateral ATR were examined 4.6 ± 2.0 (mean ± SD) yr after rupture. Gastrocnemius medialis (GM) tendon stiffness, morphology, and muscle architecture were determined using ultrasonography. The force–length relation of the plantar flexor muscles was assessed at five ankle joint angles. In addition, simulations (OpenSim) of the GM MTU force–length properties were performed with various iterations of MTU properties found between the unaffected and the affected side. Results: The affected side of the patients displayed a longer, larger, and stiffer GM tendon (13% ± 10%, 105% ± 28%, and 54% ± 24%, respectively) compared with the unaffected side. The GM muscle fascicles of the affected side were shorter (32% ± 12%) and with greater pennation angles (31% ± 26%). A mean deficit in plantarflexion moment of 31% ± 10% was measured. Simulations indicate that pairing an intact muscle with a longer tendon shifts the optimal angular range of peak force outside physiological angular ranges, whereas the shorter muscle fascicles and tendon stiffening seen in the affected side decrease this shift, albeit incompletely. Conclusions: These results suggest that the substantial changes in MTU properties found in ATR patients may partly result from compensatory remodeling, although this process appears insufficient to fully restore muscle function.
KW  - Tendon Rupture
KW  - Stiffness
KW  - Simulation
KW  - Muscle Force
KW  - Muscle Fascicle
Y1  - 2021
U6  - https://doi.org/10.1249/MSS.0000000000002592
SN  - 1530-0315
VL  - 53
IS  - 7
SP  - 1356
EP  - 1366
PB  - American College of Sports Medicine
CY  - Philadelphia, Pa.
ER  - 
TY  - JOUR
A1  - Ball, Christopher Stephen
A1  - Vögele, Stefan
A1  - Grajewski, Matthias
A1  - Kuckshinrichs, Wilhelm
T1  - E-mobility from a multi-actor point of view: Uncertainties and their impacts
JF  - Technological Forecasting and Social Change
Y1  - 2021
SN  - 0040-1625
U6  - https://doi.org/10.1016/j.techfore.2021.120925
VL  - 170
IS  - Art. 120925
PB  - Elsevier
CY  - Amsterdam
ER  -