OBJECTIVES: Based on a ferromagnetic silicone cuff for extra-aortic counterpulsation, a new assist device concept was developed. The driving force is generated by an external magnetic field, which leads to contraction of a soft magnetic cuff. The force generation capacity of the device was tested in a silicone aorta model. METHODS: Magnetic elastomers can be constructed through dispersion of micro- or nanoparticles in polymer matrices and were designed to act as soft actuators. Two magnetically active silicone cuffs were produced with a nanomagnet loading of 250 wt% (Cuff 1) and a micromagnet loading of 67 wt% (Cuff 2). The magnetic cuffs were applied on a silicone aorta model and contracted against hydrostatic pressure. RESULTS: A full contraction of Cuff 1 was possible against a maximal hydrostatic pressure of 30 cmH₂O (22 mmHg) at a magnetic flux density of 0.4 T (Tesla) and 65 cmH₂O (48 mmHg) at a magnetic flux density of 1.2 T. A 50% contraction of Cuff 2 was possible against a maximal hydrostatic pressure of 80 cmH₂O (59 mmHg) at a magnet-cuff-distance (MCD) of 0 cm. At MCDs of 1 and 2 cm a 50% contraction was possible against 33 cmH₂O (24 mmHg) and 10 cmH₂O (7 mmHg), respectively. CONCLUSIONS: Combining the advantages of magnetic elastomers with the principle of extra-aortic counterpulsation in a new assist device concept avoids the need for anticoagulation (no contact with bloodstream). With regard to the magnetic principle of action, no intra- to extracorporeal connection is needed. More experimental work is needed to further increase the force generated by the silicone cuff and to transfer the device concept into an in vivo setting.
OBJECTIVES: Based on a ferromagnetic silicone cuff for extra-aortic counterpulsation, a new assist device concept was developed. The driving force is generated by an external magnetic field, which leads to contraction of a soft magnetic cuff. The force generation capacity of the device was tested in a silicone aorta model. METHODS: Magnetic elastomers can be constructed through dispersion of micro- or nanoparticles in polymer matrices and were designed to act as soft actuators. Two magnetically active silicone cuffs were produced with a nanomagnet loading of 250 wt% (Cuff 1) and a micromagnet loading of 67 wt% (Cuff 2). The magnetic cuffs were applied on a silicone aorta model and contracted against hydrostatic pressure. RESULTS: A full contraction of Cuff 1 was possible against a maximal hydrostatic pressure of 30 cmH₂O (22 mmHg) at a magnetic flux density of 0.4 T (Tesla) and 65 cmH₂O (48 mmHg) at a magnetic flux density of 1.2 T. A 50% contraction of Cuff 2 was possible against a maximal hydrostatic pressure of 80 cmH₂O (59 mmHg) at a magnet-cuff-distance (MCD) of 0 cm. At MCDs of 1 and 2 cm a 50% contraction was possible against 33 cmH₂O (24 mmHg) and 10 cmH₂O (7 mmHg), respectively. CONCLUSIONS: Combining the advantages of magnetic elastomers with the principle of extra-aortic counterpulsation in a new assist device concept avoids the need for anticoagulation (no contact with bloodstream). With regard to the magnetic principle of action, no intra- to extracorporeal connection is needed. More experimental work is needed to further increase the force generated by the silicone cuff and to transfer the device concept into an in vivo setting.
Authors: S Scheidt; G Wilner; H Mueller; D Summers; M Lesch; G Wolff; J Krakauer; M Rubenfire; P Fleming; G Noon; N Oldham; T Killip; A Kantrowitz Journal: N Engl J Med Date: 1973-05-10 Impact factor: 91.245
Authors: Christopher S Hayward; William S Peters; Alan F Merry; Peter N Ruygrok; Paul Jansz; Gerry O'Driscoll; Robert I Larbalestier; Julian A Smith; Betty Ho; Malcolm E Legget; F Paget Milsom Journal: J Heart Lung Transplant Date: 2010-12 Impact factor: 10.247
Authors: Andrew N Davies; William S Peters; Tonglin Su; Colin E Sullivan; Theo Perkidides; F Paget Milsom; Geoffrey White Journal: Heart Lung Circ Date: 2005-07-25 Impact factor: 2.975
Authors: William L Holman; Soon J Park; James W Long; Alan Weinberg; Lopa Gupta; Anita R Tierney; Robert M Adamson; John D Watson; Edward P Raines; Gregory S Couper; Francis D Pagani; Nelson A Burton; Leslie W Miller; Yoshifumi Naka Journal: J Heart Lung Transplant Date: 2004-12 Impact factor: 10.247
Authors: Katherine Lietz; James W Long; Abdallah G Kfoury; Mark S Slaughter; Marc A Silver; Carmelo A Milano; Joseph G Rogers; Yoshifumi Naka; Donna Mancini; Leslie W Miller Journal: Circulation Date: 2007-07-16 Impact factor: 29.690