title: The circumferential loading of a direct cardiac compression assist device.
abstract: Heart disease is the developed world's largest killer. Transplantation of the failing heart remains the most effective treatment currently employed, but demand far exceeds donor supply. In a bid to address this imbalance, the use of mechanical circulatory support has been explored since the mid-1960s. This paper utilizes one such device, which achieves assistance by mechanically compressing the epicardial surface of the failing heart. The circumferential normal loading of the device is investigated, showing how frictional effects inherent to the device's operation affect localized surface pressure. Results showed that as distance from the device's actuator increased, assistive systolic force reduced, whilst device constriction to ventricular filling detrimentally increased. Active device relaxation was shown to limit the diastolic effect outlined above, providing the simulated diseased heart with an improved cardiac output. The results also raise questions concerning device in-vivo positioning and short-comings with the current heart simulator.
authors.affiliation: University of Leeds, Leeds, LS2 9JT, UK. men9dgk@leeds.ac.uk
authors.forename: David G
authors.initials: DG
authors.lastname: Keeling
authors.forename: Martin C
authors.initials: MC
authors.lastname: Levesley
authors.forename: Peter G
authors.initials: PG
authors.lastname: Walker
authors.forename: Ben M
authors.initials: BM
authors.lastname: Hanson
authors.forename: Kevin
authors.initials: K
authors.lastname: Watterson
authors.forename: Codruta I
authors.initials: CI
authors.lastname: Pereni
authors.forename: Osama
authors.initials: O
authors.lastname: Jaber
mesh_terms: D001783:Blood Flow Velocity / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D019245:Compressive Strength; D003198:Computer Simulation; D017076:Computer-Aided Design; D004867:Equipment Design; D019544:Equipment Failure Analysis; D017276:Friction; D006321:Heart / Q000502:physiology*; D006353:Heart-Assist Devices; D008955:Models, Cardiovascular