Compressive properties of commercially available polyurethane foams as mechanical models for osteoporotic human cancellous bone

<p>Abstract</p> <p>Background</p> <p>Polyurethane (PU) foam is widely used as a model for cancellous bone. The higher density foams are used as standard biomechanical test materials, but none of the low density PU foams are universally accepted as models for osteoporotic (OP) bone. The aim of this study was to determine whether low density PU foam might be suitable for mimicking human OP cancellous bone.</p> <p>Methods</p> <p>Quasi-static compression tests were performed on PU foam cylinders of different lengths (3.9 and 7.7 mm) and of different densities (0.09, 0.16 and 0.32 g.cm^-3), to determine the Young's modulus, yield strength and energy absorbed to yield.</p> <p>Results</p> <p>Young's modulus values were 0.08–0.93 MPa for the 0.09 g.cm^-3foam and from 15.1–151.4 MPa for the 0.16 and 0.32 g.cm^-3foam. Yield strength values were 0.01–0.07 MPa for the 0.09 g.cm^-3foam and from 0.9–4.5 MPa for the 0.16 and 0.32 g.cm^-3foam. The energy absorbed to yield was found to be negligible for all foam cylinders.</p> <p>Conclusion</p> <p>Based on these results, it is concluded that 0.16 g.cm^-3PU foam may prove to be suitable as an OP cancellous bone model when fracture stress, but not energy dissipation, is of concern.</p

HRS/EHRA/ECAS expert consensus statement on catheter and surgical ablation of atrial fibrillation: Recommendations for personnel, policy, procedures and follow-up. A report of the Heart Rhythm Society (HRS) Task Force on catheter and surgical ablation of atrial fibrillation

During the past decade, catheter ablation of atrial fibrillation (AF) has evolved rapidly from a highly experimental unproven procedure, to its current status as a commonly performed ablation procedure in many major hospitals throughout the world. Surgical ablation of AF, using either standard or minimally invasive techniques, is also performed in many major hospitals throughout the world. The purpose of this Consensus Statement is to provide a state-of-the-art review of the field of catheter and surgical ablation of AF, and to report the findings of a Task Force, convened by the Heart Rhythm Society and charged with defining the indications, techniques, and outcomes of this procedure. The Heart Rhythm Society was pleased to develop this Consensus Statement in partnership with the European Heart Rhythm Association and the European Cardiac Arrhythmia Society. This statement summarizes the opinion of the Task Force members based on their own experience in treating patients, as well as a review of the literature, and is directed to all health care professionals who are involved in the care of patients with AF, particularly those who are undergoing or are being considered for catheter or surgical ablation procedures for AF. This statement is not intended to recommend or promote catheter ablation of AF. Rather the ultimate judgment regarding care of a particular patient must be made by the health care provider and patient in light of all the circumstances presented by that patient. In writing a "consensus" document, it is recognized that consensus does not mean that there was complete agreement among all Task Force members. We attempted to identify those aspects of AF ablation for which a true "consensus" could be identified ( Tables 1 and 2 ). Surveys of the entire Task Force were used to identify these areas of consensus. The main objective of this document is