1、Designation: F2213 06 (Reapproved 2011)F2213 17Standard Test Method forMeasurement of Magnetically Induced Torque on MedicalDevices in the Magnetic Resonance Environment1This standard is issued under the fixed designation F2213; the number immediately following the designation indicates the year ofo
2、riginal adoption or, in the case of revision, the year 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 This test method covers the measurement of the magnetically
3、induced torque produced by the static magnetic field in themagnetic resonance environment on medical devices and the comparison of that torque to the equivalent torque applied by thegravitational force to the implant.a user-specified acceptance criterion.1.2 This test method does not address other p
4、ossible safety issues which include may include, but are not limited to issues ofmagnetically induced force due to spatial gradients in the static magnetic field, RF heating, induced heating, to, magneticallyinduced deflection force, tissue heating, device malfunction, imaging artifacts, acoustic no
5、ise, interaction among devices, and thefunctionality of the device and the MR system.1.3 The torque considered here is the magneto-static torque due to the interaction of the MRI static magnetic field with themagnetization inof the implant. The dynamic torque due to interaction of the static field w
6、ith eddy currents induced in a rotatingdevice is not addressed in this test method. Currents Torque induced by currents in lead wires may induce a torque as well.is notaddressed by this standard.1.4 The sensitivity of the torque measurement apparatus must be greater thanmethods in this standard are
7、applicable for MRsystems with a horizontal magnetic field. Not all of the methods described in this standard are applicable for use in an MR systemwith a vertical magnetic field. The Suspension Method and the Low Friction Surface Method require gravity to be orthogonal tothe magnetically induced tor
8、sion and may not be performed using a vertical magnetic field. The Torsional Spring and PulleyMethods can be adapted to work in a vertical magnetic field, however the example apparatus are not appropriate for 110 the “gravitytorque,” the product of the devices maximum linear dimension and its weight
9、.use in a vertical magnetic field. The CalculationBased on Measured Displacement Force Method is independent of the MR system and thus could be used for an MR system witha vertical magnetic field.1.5 The values stated in SI units are to be regarded as standard. No other units of measurement are incl
10、uded in this standard.1.6 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibilityof the user of this standard to establish appropriate safety safety, health, and healthenvironmental practices and determine theapplicability of re
11、gulatory limitations prior to use.1.7 This international standard was developed in accordance with internationally recognized principles on standardizationestablished in the Decision on Principles for the Development of International Standards, Guides and Recommendations issuedby the World Trade Org
12、anization Technical Barriers to Trade (TBT) Committee.2. Referenced Documents2.1 ASTM Standards:2F2052 Test Method for Measurement of Magnetically Induced Displacement Force on Medical Devices in the MagneticResonance EnvironmentF2119 Test Method for Evaluation of MR Image Artifacts from Passive Imp
13、lantsF2182 Test Method for Measurement of Radio Frequency Induced Heating On or Near Passive Implants During MagneticResonance Imaging1 This test method is under the jurisdiction of ASTM Committee F04 on Medical and Surgical Materials and Devices and is the direct responsibility of SubcommitteeF04.1
14、5 on Material Test Methods.Current edition approved Oct. 1, 2011Sept. 1, 2017. Published October 2011October 2017. Originally approved in 2002. Last previous edition approved in 20062011 asF2213 06.F2213 06 (2011). DOI: 10.1520/F2213-06R11.10.1520/F2213-17.2 For referencedASTM standards, visit theAS
15、TM website, www.astm.org, or contactASTM Customer Service at serviceastm.org. For Annual Book of ASTM Standardsvolume information, refer to the standards Document Summary page on the ASTM website.This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an in
16、dication of what changes have been made to the previous version. Becauseit may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current versionof the standard as published by ASTM is to be
17、 considered the official document.Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States1F2503 Practice for Marking Medical Devices and Other Items for Safety in the Magnetic Resonance Environment2.2 Other Standards:3IEC 60601-2-33 Ed. 2.0 M
18、edical Electrical EquipmentPart 2: Particular Requirements for the Safety of Magnetic ResonanceEquipment for Medical Diagnosis, 2002Medical electrical equipment - Part 2-33: Particular requirements for the basic safetyand essential performance of magnetic resonance equipment for medical diagnosisISO
19、 13485:2003(E)13485 Medical DevicesQuality Management SystemsRequirements for Regulatory Purposes, definition3.7devices - Quality management systems - Requirements for regulatory purposes4ISO TS 10974 Assessment of the safety of magnetic resonance imaging for patients with an active implantable medi
20、cal device3. Terminology3.1 DefinitionsDefinitions:For the purposes of this test method, the definitions in 3.1.1 3.1.18 shall apply:3.1.1 diamagnetic materialmaterial, na material whose relative permeability is less than unity.3.1.2 ferromagnetic materialmaterial, na material whose magnetic moments
21、 are ordered and parallel producing magneti-zation in one direction.3.1.3 magnetic induction or magnetic flux density (B in T)T), nthat magnetic vector quantity which at any point in amagnetic field is measured either by the mechanical force experienced by an element of electric current at the point
22、, or by theelectromotive force induced in an elementary loop during any change in flux linkages with the loop at the point. The magneticinduction is frequently referred to as the magnetic field. B0 is the static field in an MR system. Plain type indicates a scalar (forexample, B) and bold type indic
23、ates a vector (for example, B).3.1.4 magnetic field strength (H in A/m)A/m), nstrength of the applied magnetic field.3.1.5 magnetic resonance (MR)(MR), nresonant absorption of electromagnetic energy by an ensemble of atomic particlesituated in a magnetic field.3.1.6 magnetic resonance diagnostic dev
24、icea device intended for general diagnostic use to present images which reflect thespatial distribution or magnetic resonance spectra, or both, which reflect frequency and distribution of nuclei exhibiting nuclearmagnetic resonance. Other physical parameters derived from the images or spectra, or bo
25、th, may also be produced.3.1.6 magnetic resonance (MR) environmentenvironment, nvolume within the 0.50 mT (5 gauss (G) line of an MR system,which includes the entire three dimensional three-dimensional volume of space surrounding the MR scanner. For cases where the0.50 mT line is contained within th
26、e Faraday shielded volume, the entire room shall be considered the MR environment.3.1.7 magnetic resonance equipmentequipment, nmedical electrical equipment which is intended for in-vivomagneticresonance examination of a patient. The MR equipment comprises all parts in hardware and software from the
27、 supply mains tothe display monitor. The MR equipment is a Programmable Electrical Medical System (PEMS). IEC 60601-2-333.1.9 magnetic resonance examination (MR Examination)process of acquiring data by magnetic resonance from a patient.3.1.8 magnetic resonance imaging (MRI)(MRI), nimaging technique
28、that uses static and time varying time-varyingmagnetic fields to provide images of tissue by the magnetic resonance of nuclei.3.1.9 magnetic resonance system (MR System)System), nensemble of MR equipment, accessories including means fordisplay, control, energy supplies, and the MR environment.IEC 60
29、60123360601-2-333.1.10 magnetically induced displacement forceforce, nforce produced when a magnetic object is exposed to the spatialgradient of a magnetic field. This force will tend to cause the object to translate in the gradient field.3.1.11 magnetically induced torquetorque, ntorque produced wh
30、en a magnetic object is exposed to a magnetic field. Thistorque will tend to cause the object to align itself along the magnetic field in an equilibrium direction that induces no torque.3.1.12 magnetization (M in T)T), nmagnetic moment per unit volume.volume3.1.13 medical devicedevice, nany instrume
31、nt, apparatus, implement, machine, appliance, implant, in vitro reagent orcalilbrator,calibrator, software, material, or other similar or related article, intended by the manufacturer to be used, alone or incombination, for human beings for one or more of the specific purpose(s) of:(1) diagnosis, pr
32、evention, monitoring, treatment, or alleviation of disease,(2) diagnosis, monitoring, treatment, alleviation of, or compensation for an injury,(3) investigation, replacement, modification, or support of the anatomy or of a physiological process,(4) supporting or sustaining life,(5) control of concep
33、tion,(6) disinfection of medical devices, and(7) providing information for medical purposes by means of in vitro examination of specimens derived from the human body, and which does not achieveits primary intended action in or on the human body by pharmacological, immunological, or metabolic means,
34、but which may be assisted in its functionby such means.3 Available from American National Standards Institute (ANSI), 25 W. 43rd St., 4th Floor, New York, NY 10036, http:/www.ansi.org.4 Specifically, definition 3.11.F2213 172(1) diagnosis, prevention, monitoring, treatment, or alleviation of disease
35、;(2) diagnosis, monitoring, treatment, alleviation of, or compensation for an injury;(3) investigation, replacement, modification, or support of the anatomy or of a physiological process;(4) supporting or sustaining life;(5) control of conception;(6) disinfection of medical devices; and(7) providing
36、 information for medical purposes by means of in vitro examination of specimens derived from the human body, and which does not achieveits primary intended action in or on the human body by pharmacological, immunological, or metabolic means, but which may be assisted in its functionby such means.ISO
37、 134853.1.14 paramagnetic materialmaterial, na material having a relative permeability which is slightly greater than unity, andwhich is practically independent of the magnetizing force.3.1.15 passive implantimplant, nan implant that serves its function without the supply of electrical power.3.1.16
38、tesla, (T)(T), nthe SI unit of magnetic induction equal to 104 gauss (G).4. Summary of Test Method4.1 The static magnetic field associated with an MR system produces a torque on a device that acts to align the long axis ofthe object with the direction of the magnetic field. Five methods for measurem
39、ent or assessment of magnetically induced torqueare given in this standard: the Suspension Method, the Low Friction Surface Method, the Torsional Spring Method, the PulleyMethod, and the Calculation Based on Measured Displacement Force Method.4.2 The Suspension Method and the Low Friction Surface Me
40、thod are not appropriate for devices for which the magneticallyinduced torque is expected to be greater than the torque due to gravity.4.3 The Low Friction Surface Method is performed by placing the device on a low friction non-metallic, non-conductive surfaceas near as practical to the isocenter of
41、 the MR system. The device is then rotated in defined angular increments while alignmentor rotation of the device with the static magnetic field is observed. If rotation of the device is not observed, an upper bound onthe magnetically induced torque is estimated using the coefficient of friction bet
42、ween the surface and the device and the weightof the device. If alignment or rotation of the device is observed, then either the Torsional Spring Method or the Pulley Method shallbe performed. The coefficient of friction is calculated from the device weight and the angle of repose (the angle in whic
43、h theimplant is on the verge of sliding off the low friction surface) which is measured outside the MR environment.4.4 The static field in a magnetic resonance system produces a torque on a device that acts to align the long axis of the objectwith the magnetic field. The torque is evaluated using a
44、torsional pendulum method. Torsion Spring Method determines themagnetically induced torque using a torsion pendulum. A device is placed on a holder suspended by a torsionaltorsion spring. Theapparatus is placed in the center of the magnetic resonance equipment magnet where the magnetic field is unif
45、orm. The torque isdetermined from the measurement of the deflection angle of the holder from its equilibrium position. The frame holding the springand holder assembly is rotated and the torque as a function of angle of the implant is determined. The maximal magnetic torqueis compared to the worst ca
46、se gravitygravitational torque, defined as the product of the maximum linear dimension of the deviceand the device weight.4.5 The Pulley Method allows determination of the maximum magnetically induced torque of the device using a low frictionpulley attached to a rotating platform. The device is fixe
47、d on the platform while positioning the device to be centered as near aspractical to isocenter of the MR system. Using a lightweight string attached to the pulley and a force gauge, the platform is rotatedby pulling the force gauge in a direct line away from the torque fixture. The maximum torque is
48、 determined by using the maximumreading from the force gauge.4.6 The Suspension Method is a qualitative method that is performed by suspending the device by a lightweight string in alocation as near as practical to the isocenter of the MR system. The device is then rotated in defined angular increme
49、nts whilemovement or rotation of the device to align with the static magnetic field is observed. If rotation of the device is not observed,the magnetically induced torque is small and no further evaluation is required. If rotation of the device is observed, then the LowFriction Surface Method, the Torsional Spring Method, or the Pulley Method shall be performed.4.7 The Calculation Based on Measured Displacement Force Method provides an upper bound for the magnetically inducedtorque based on magnetically induced displacement force m
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