YY/T 0987.1-2016Implants for Surgery - Magnetic Resonance Compatibility - Part 1: Safety Marking (English PDF)

Foreword

YY/T 0987 Implants for Surgery - Magnetic Resonance Compatibility is divided into the following parts:

---Part 2: Magnetically Induced Displacement Force Test Method;

---Part 3: Evaluation of MR Image Artifacts from Passive Implants;

---Part 5: Magnetically Induced Torque Test Method.

This is the first part of YY/T 0987.

This Part was drafted in accordance with the rules in GB/T 1.1-2009.

This Part was formulated in accordance with the Act of Redrafting and ASTM F2503- 2008 Standard Practice for Marking Medical Devices and Other Items for Safety in the Magnetic Resonance Environment.

In comparison with ASTM F2503-2008, this Part has the following technical differences:

---In terms of the scope of application of the standard, this Part is also applicable to other medical devices or items that enter the magnetic resonance environment. If this Part conflicts with relevant laws and regulations, the laws and regulations shall prevail.

---In terms of normative references, this Part has made some adjustment with technical differences, so as to adapt to the technical conditions in China. The condition of such adjustment is intensively reflected in Chapter 2 “Normative References”. Please see the specific adjustment below:

Please be noted that certain contents in this document might involve patents. The institution that issues this document shall not undertake any responsibility of identifying these patents.

This Part was proposed by China Food and Drug Administration.

This Part shall be under the jurisdiction of National Technical Committee 110 on Implants for Surgery and Orthopedic Devices of Standardization Administration of China (SAC/TC 110).

The main drafting organizations of this Part: China Food and Drug Administration, Tianjin Medical Devices Quality Supervision and Testing Center, MicroPort Scientific Corporation (Shanghai).

The main drafters of this Part: Lijia, Miaohui, Li Libin, Sunbing, Shi Haifeng.

1 Scope

This Part of YY/T 0987 specifies safety marking of medical devices and other items in the magnetic resonance (MR) environment, so as to provide prompt message on safety.

magnetic resonance environment can also refer to this Part for safety marking.

This Part has the following purposes:

(1) Suggest that an item, that might enter MR environment, should be permanently marked, so as to indicate whether this item is safe in MR environment;

(2) Suggest the information that shall be included in the marking.

Sometimes it is not realistic to directly mark on implants and certain medical devices. When it is impossible to directly mark on them, it is suggested to mark on labels and patients’ information cards.

This Part does not include the content of image artifact, because artifact does not belong to the issue of safety.

This Part adopts numerical value under international system of units as the standard; numerical value in the brackets shall merely be considered as reference.

This Part does not attempt to elaborate all the involved safety questions, even though those safety questions are related with the usage. Determining appropriate safety and health specifications and clarifying the applicability of management limit before application is the responsibility on the users of this Standard.

2 Normative References

The following documents are indispensable to the application of this Standard. In terms of references with a specified date, only versions with a specified date are applicable to this Standard. The latest version (including all the modifications) of references without a specified date is also applicable to this Standard.

3 Terms and Definitions

The following terms and definitions are applicable to this document.

4 Significance and Application

In MR environment, medical devices and other items have caused severe injuries, and even death to patients and other individuals.

This Part provides a set of consistent safety markings, which indicates MR conditions that are acceptable to medical devices and other items. This Part provides simple markings and terms to reduce injuries and other accidents caused by hazardous items in MR environment (please refer to Appendix A).

5 Marking Method

Marking shall not influence the performance or functions of items being marked. In addition, within the expected service life, marking shall maintain its readability.

6 Necessary Information

Through experiments, obtain items’ behavior attributes in MR environment, especially items’ magnetically induced displacement force (refer to YY/T 0987.2), magnetically induced torque (refer to YY/T 0987.5) and radio frequency induced heating (refer to YY/T 0987.4) in MR environment.

Any parameters that might influence items’ safety performance shall be listed out; conditions that generate hazards shall be described.

7 Information Contained in MR Marking

Since medical devices and other items have various dimensions, the content contained in practical marking also differs. In terms of implants, MR marking shall be added on package’s label (including instruction on usage and package inserts) and patients’ information cards. In terms of non-implants applied in MR environment, marking shall be added on a conspicuous location and label. Certain items (for example, extremely small or extremely thin items) don’t have sufficient surface for marking; when it is impossible for direct marking, marking shall be added on the label. Information that shall at least be provided---in accordance with the test mentioned in Chapter 6, use the markings in Table 1 and Table 2 to mark items as MR safe, MR conditional and MR unsafe. The marking of MR safe is constituted of a green block with the letter “MR” (refer to Table 1). There are two optional modes: when colorful marking is not applicable, use black and white printing (refer to Table 2). In order to enhance the degree of recognizability and the amount of information, it is strongly suggested that colorful marking shall be adopted. In terms of the colorful marking and black and white marking in Table 1 and Table 2, choose the marking that would the most easily be recognized by individuals. The marking of MR conditional is constituted of a yellow equilateral triangle with the letter “MR”, and black peripheral frame (refer to Table 1). The bottom line of the triangle is underneath the letter. When colorful marking is not applicable, use black and white printing (refer to Table 2). In order to enhance the degree of recognizability and the amount of information, it is strongly suggested that colorful marking shall be adopted. In terms of MR conditional safe items, information described in 3.9 and Chapter 6 shall be provided on the label (necessary location on instruction on usage, package inserts, manual on usage, patients’ information card, etc.). In order to supplement information described in 3.9 and Chapter 6, MR conditional marking can be attached with an auxiliary marking, so as to describe specific MR conditions, under which, items can be safely used. […]

Appendix A Principle

A.1 This Part aims at using a group of easily recognizable markings and terms to indicate items’ safety in or near MR scanner. In 1997, in the guidance draft of Interactive Influence of Medical Devices and Magnetic Resonance Imaging System, FDA defined two terms for the first time: MR safe and MR compatible, so as to describe the safety in MR system and peripheral devices. The definitions previously used are as follows: MR safe: after being proved by experiments, devices that do not generate hazards to patients or other individuals in MR environment but might have influence on the diagnostic information. When MR safe or MR compatible is being marked, test conditions shall be clarified, because a device’s safety or compatibility in a certain environment does not signify that it is also safe in magnetic resonance environment, which is extremer. MR compatible: devices that are safe in magnetic resonance environment; have no obvious influence on diagnostic information and can be normally operated. When MR safe or MR compatible is being marked, test conditions shall be clarified, because a device’s safety or compatibility in a certain environment does not signify that it is also safe in magnetic resonance environment, which is extremer. However, this kind of definition would easily lead to utmost confusions and often lead to misunderstandings. Users often wrongly assume that items with the marking of MR safe or MR compatible are safe or compatible in any MR environment. The differences of MR environment mainly reflect in magnetic field strength and radio frequency conditions. Therefore, the influence on items under a certain condition might differ from the influence on items under another condition. In addition, some devices which are marked MR safe or MR compatible in accordance with the old terms are requested to be attached with the restriction of Gaussian line or the restriction of radio frequency pulse sequence, so as to guarantee the devices’ safe application in MR environment. In brief, if test conditions are not clearly pointed out, it is impossible to determine whether a device is MR safe or MR compatible. A.2 This Part proposes new terms (MR safe, MR unsafe and MR conditional), which aims at eliminating these confusions. […]