1、Designation:F247707(Reapproved 2013)Standard Test Methods forin vitro Pulsatile Durability Testing of Vascular Stents1This standard is issued under the fixed designation F2477;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year
2、of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 These test methods cover the determination of thedurability of a vascular stent by exposing it to physiologicallyrelevan
3、t diametric distension levels by means of hydrodynamicpulsatile loading.This testing occurs on a stent test specimenthat has been deployed into a mock(elastically simulated)vessel.The typical duration of this test is 10 years of equivalentuse(at 72 beats per minute),or at least 380 million cycles.1.
4、2 These test methods are applicable to balloon-expandableand self-expanding stents fabricated from metals and metalalloys.It does not specifically address any attributes unique tocoated stents,polymeric stents,or biodegradable stents,al-though the application of this test method to those products is
5、not precluded.1.3 These test methods do not include recommendations forendovascular grafts(“stent-grafts”)or other conduit productscommonly used to treat aneurismal disease or peripheral vesseltrauma or to provide vascular access,although some informa-tion included herein may be applicable to those
6、devices.1.4 These test methods are valid for determining stentfailure due to typical cyclic blood vessel diametric distension.These test methods do not address other modes of failure suchas dynamic bending,torsion,extension,crushing,or abrasion.1.5 These test methods do not address test conditions f
7、orcurved mock vessels.1.6 These test methods do not address test conditions foroverlapping stents.1.7 The values stated in SI units are to be regarded asstandard.No other units of measurement are included in thisstandard.1.8 This standard does not purport to address all of thesafety concerns,if any,
8、associated with its use.It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use.1.9 General CaveatThis document contains guidance fortesting as is currently carried out in most
9、laboratories.Othertesting techniques may prove to be more effective and areencouraged.Whichever technique is used,it is incumbent uponthe tester to justify the use of the particular technique,instrument,and protocol.This includes the choice of andproper calibration of all measuring devices.Deviation
10、s fromany of the suggestions in this document may be appropriate butmay require the same level of comprehensive justification thatthe techniques described herein will require.2.Referenced Documents2.1 Other Documents:ISO 7198:1998(e),8.10,Determination of Dynamic Com-pliance2FDA Guidance Document 15
11、45,Non-Clinical Tests andRecommended Labeling for Intravascular Stents and As-sociated Delivery Systems,(issued January 13,2005)33.Terminology3.1 Definitions of Terms Specific to This Standard:3.1.1 cardiac cycle,ndefined as one cycle between dia-stolic and systolic pressures.3.1.2 compliance,nthe c
12、hange in inner diameter of avessel due to cyclic pressure changes.Compliance,ifcalculated,shall be expressed as a percentage of the diameterchange per 100 mm Hg and defined per ISO 7198,8.10.5:%Compliance/100 mm Hg5Dp2 2 Dp1!3104Dp1p2 2 p1!(1)where:Dp1=inner diameter at the pressure of p1,Dp2=inner
13、diameter at the pressure of p2,p1=lower pressure value(diastolic),in mm Hg,andp2=higher pressure value(systolic),in mm Hg.3.1.3 diametric strain,na change in mock artery diameterdivided by the initial diameter.This term does not relate to the1These test methods are under the jurisdiction of ASTM Com
14、mittee F04 onMedical and Surgical Materials and Devices and is the direct responsibility ofSubcommittee F04.30 on Cardiovascular Standards.Current edition approved March 1,2013.Published March 2013.Originallyapproved in 2006.Last previous edition approved in 2007 as F2477 07.DOI:10.1520/F2477-07R13.
15、2Available from American National Standards Institute(ANSI),25 W.43rd St.,4th Floor,New York,NY 10036,http:/www.ansi.org.3Available from Food and Drug Administration(FDA),5600 Fishers Ln.,Rockville,MD 20857,http:/www.fda.gov.This document available at http:/www.fda.gov/cdrh/ode/guidance/1545.pdf.Cop
16、yright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 mechanical strain seen in the stent material.The diametricstrain can be identified as:diametric strain5Dp2 2 Dp1!Dp1(2)that is,diametric strain5maxID2 minID!minID3.1.4 distension,nthe change in diameters;such as theinner diameter(ID)of a vessel due to a pressure change.Theterm“diametric distension”is meant to represent the change ininner diameter of a blood vessel during each pulse of blood
