自《医疗器械可用性工程注册审查指导原则》 发布以来，可用性工程的热度一直不减，在各个三方机构和咨询公司的推波助澜下，外加GB 9706.1三版实施进入正常化下，可用性的相关话题就越发显得热火。对于指导原则有太多解读了，就不去抽这个热闹了，今天来聊聊后台很多小伙伴私信我的一个普遍问题， 就是到底该如何看到可用性的标准。
有这个问题的原因在于目前国内现行有效的可用性工程标准是YY/T 1474-2016 医疗器械可用性工程对医疗器械的应用, 指导原则里也引用了这个标准，但是YY/T 1474-2016 等同转换于IEC 62366:2007，同时指导原则还引用了 IEC 62366-1:2015+A1:2020, Medical devices - Part 1: Application of usability engineering to medical devices， 然后从IEC 62366:2007 到IEC 62366-1:2015+A1:2020，中间还有IEC 62366:2007+A1:2014 和IEC 62366-1:2015，这些版本间的差异显然还是有的，而且指导原则本身不是过程性标准，对于整个可用性过程的展开在细节上没有过多的阐述，因此企业在开展可用性研究的时候还是会回归到标准要求来执行，但是由于标准版本上的差异，已经标准本身跟指导原则上的差异，导致大家对到底该按照什么要求去执行有点迷惑。
好吧，今天咱们就来梳理一下这个可用性工程标准的流程到底有多大差异，差异中寻找平衡点来同时满足指导原则和标准。
先理解一下什么使用的多种方式：
可以看出所谓的可用性工程其实研究的是正常使用下的使用错误和可合理预见下的使用中非正常使用。
使用错误和可合理预见的非正常使用通过设备的用户界面跟使用者产生交互，进而设备产生非预期的反应，由此可能产生危险或危险情况。
危险和危险情况，那就是我们熟悉的风险管理过程的主要研究对象了，将危险和危险情况结合到产品的风险管理过程中去，进一步分析风险并控制风险， 这就是可用性的设计和实施。
风险管控措施实施后，到底能不能降低使用错误或者可合理预见的非正常使用，进而保证设备的有效性和效率，那就需要有总结性测试来确认。测试完了还需要来看是否有新的使用错误或危险和危险情况产生，是否需要进一步控制或揭露。
大体的可用性过程就是这样，废话不多说了，直接上今天的主题，这四个版本的标准的差异：
| YY/T1474-2016 (IEC 62366:2007 IDT) | IEC 62366:2007+A1:2014 | IEC 62366-1:2015 | Gap Analysis | IEC 62366-1:2015+A1:2020 |
| 4 * Principles | 4 * Principles | |||
| 4.1 General requirements | 4.1 General requirements | |||
| 4.1.1 * USABILITY ENGINEERING PROCESS | Same | 4.1.1 USABILITY ENGINEERING PROCESS | Additional requirements： 1. USABILITY ENGINEERING activities for a MEDICAL DEVICE shall be planned, carried out, and documented by personnel competent on the basis of appropriate education, training, skills or experience. 2. Relationship with ISO 13485; 3. Relationship with ISO 14971 | Update the reference standards revision. |
| 4.1.2 RESIDUAL RISK | Same | 4.1.2 Risk control as it relates to USER interface design | Define the risk control measure
priority： a) inherent SAFETY by design; b) protective measures in the MEDICAL DEVICE itself or in the manufacturing PROCESS; c) information for SAFETY. | a) inherently
safe design and manufacture; b) protective measures in the MEDICAL DEVICE itself or in the manufacturing PROCESS; and c) information for SAFETY and, where appropriate, training to USERS |
| 4.1.3 Information for SAFETY | Same | 4.1.3 Information for SAFETY as it relates to USABILITY | Detail the information as risk
control measure requirement： – is perceivable by, – is understandable to, and – supports CORRECT USE of the MEDICAL DEVICE by USERS of the intended USER PROFILES in the context of the intended USE ENVIRONMENT. | Wording change. |
| 4.2 * USABILITY ENGINEERING FILE | Same | 4.2 USABILITY ENGINEERING FILE | Same | Same |
| 4.3 Scaling of the USABILITY ENGINEERING effort | Same | 4.3 Tailoring of the USABILITY ENGINEERING effort | The usability engineering effort
may vary: a) the size and COMPLEXITY of the USER INTERFACE; b) the SEVERITY of the HARM associated with the use of the MEDICAL DEVICE; c) the extent or complexity of the USE SPECIFICATION; d) the presence of USER INTERFACE OF UNKNOWN PROVENANCE; and e) the extent of the modification to an existing MEDICAL DEVICE USER INTERFACE that had been subjected to the USABILITY ENGINEERING PROCESS | Same |
| 5 * USABILITY ENGINEERING PROCESS | 5 * USABILITY ENGINEERING PROCESS | |||
| 5.1 * Application specification. | Same | 5.1 * Prepare USE SPECIFICATION | Simialr, “ intended conditions of use” was replaced by "USE ENVIRONMENT" and Application spec was replaced by USE SPEIFICATION. | Wording change. |
| 5.2 * Frequently used functions | Same | N/A | No such requirement. | |
| 5.3 Identification of HAZARDS and HAZARDOUS SITUATIONS related to USABILITY | ||||
| 5.3.1 Identification of characteristics related to SAFETY | Same User profiles+Frequently used functions | 5.2 * Identify USER INTERFACE characteristics related to SAFETY and potential USE ERRORS | Identify USER INTERFACE characteristics related to safety and POF from particular standard, then based on them to identify use errors. | The results of this identification of characteristics related to SAFETY and potential USE ERRORS shall be stored in the USABILITY ENGINEERING FILE |
| 5.3.2 * Identification of known or foreseeable HAZARDS and HAZARDOUS SITUATIONS | Same | 5.3 * Identify known or foreseeable HAZARDS and HAZARDOUS SITUATIONS | The identification is simplfied
as: During the identification of HAZARDS and HAZARDOUS SITUATIONS, the following shall be considered: – USE SPECIFICATION, including USER PROFILE(S) (see 5.1); – information on HAZARDS and HAZARDOUS SITUATIONS known for existing USER INTERFACES of MEDICAL DEVICES of a similar type, if available; and – identified USE ERRORS (see 5.2) | Refer to the latest standard of ISO 14971 |
| 5.4 * Identify and describe HAZARD-RELATED USE SCENARIOS | HAZARD-RELATED USE SCENARIO
shall include all TASKS and their sequences as well as the SEVERITY of the associated HARM. | Same | ||
| 5.5 * Select the HAZARD-RELATED USE SCENARIOS for SUMMATIVE EVALUATION | HAZARD-RELATED USE SCENARIOS to
be included in the SUMMATIVE EVALUATION | The summative evaluation shall
include: – all HAZARD-RELATED USE SCENARIOS; or – a subset of the HAZARD-RELATED USE SCENARIOS based on the SEVERITY of the potential HARM that could be caused by USE ERROR (e.g. for which medical intervention would be needed); or – a subset of the HAZARD-RELATED USE SCENARIOS based on the SEVERITY of the potential HARM and based on other circumstances specific to the MEDICAL DEVICE and the MANUFACTURER. | ||
| 5.4 PRIMARY OPERATING FUNCTIONS | Same | N/A | ||
| 5.5 * USABILITY SPECIFICATION | Same | 5.6 * Establish USER INTERFACE SPECIFICATION | The USER INTERFACE SPECIFICATION
shall consider: – the USE SPECIFICATION (see 5.1); – the known or foreseeable USE ERRORS associated with the MEDICAL DEVICE (see 5.2); and – the HAZARD-RELATED USE SCENARIOS (see 5.4). The USER INTERFACE SPECIFICATION shall include: – testable technical requirements relevant to the USER INTERFACE, including the requirements for those parts of the USER INTERFACE associated with the selected RISK CONTROL measures; – an indication as to whether ACCOMPANYING DOCUMENTATION is required; and – an indication as to whether MEDICAL DEVICE-specific training is required. | Same |
| 5.6 USABILITY VALIDATION plan | Same | 5.7 * Establish USER INTERFACE EVALUATION plan | ||
| 5.7.1 General | More detail about the plan elements. | Should consider the USER GROUPS are intended to be included in the test; | ||
| 5.7.2 FORMATIVE EVALUATION planning | FORMATIVE EVALUATION
planning: a) the evaluation methods being used; b) which part of the USER INTERFACE is being evaluated; and c) when in the USABILITY ENGINEERING PROCESS to perform each of the USER INTERFACE EVALUATIONS. | Same | ||
| 5.7.3 SUMMATIVE EVALUATION planning | a) the evaluation method being
used and a rationale that the method produces OBJECTIVE EVIDENCE b) which part of the USER INTERFACE is being evaluated; c) where applicable, the criteria for determining whether the information for SAFETY is perceivable, understandable and supports CORRECT USE of the MEDICAL DEVICE (4.1.3); d) * the availability of the ACCOMPANYING DOCUMENTATION and provision of training during the SUMMATIVE EVALUATION; and e) * for a USABILITY TEST, – the test environment and conditions of use and a rationale for how they are adequately representative of the actual conditions of use; – the method of collecting data during the USABILITY TEST for the subsequent analysis of observed USE ERRORS. | e) * for a USABILITY TEST, – how the characteristics of the test participants are representative of the intended USER PROFILES; – justifying how the test participants are grouped into distinct USER GROUPS for the purpose of determining the number of test participants; – the test environment and conditions of use and a rationale for how they are adequately representative of the intended USE ENVIRONMENT; and – the definition of CORRECT USE for each HAZARD-RELATED USE SCENARIO; and – the method of collecting data during the USABILITY TEST for the subsequent analysis of observed USE ERRORS and use difficulties. | ||
| 5.7 USER INTERFACE design and implementation | Same | 5.8 Perform USER INTERFACE design, implementation and FORMATIVE EVALUATION | FORMATIVE EVALUATION should performed during
the design and implementation to identify the new use error, HAZARDS, HAZARDOUS SITUATIONS or
HAZARD-RELATED USE SCENARIOS. And the ACCOMPANYING DOCUMENTATION and training/training materials should be consider during the USER INTERFACE deisgn. | Same |
| 5.8 * USABILITY VERIFICATION | Same | N/A | It is same as the FORMATIVE EVALUATION | |
| 5.9 * USABILITY VALIDATION | Same | 5.9 Perform SUMMATIVE EVALUATION of the USABILITY of the USER INTERFACE | Testing: perform a SUMMATIVE EVALUATION of each HAZARD-RELATED USE
SCENARIO selected in 5.5 on the final or production equivalent USER
INTERFACE; Data analysis: The data from the SUMMATIVE EVALUATION shall be analysed to identify the potential consequences of all USE ERRORS that occurred; Follow action: If new USE ERRORS, HAZARDS, HAZARDOUS SITUATIONS or HAZARD-RELATED USE SCENARIOS are discovered during the data analysis: – if yes, then the MANUFACTURER shall repeat the activities of Clause 5 as appropriate; – if not, the MANUFACTURER shall determine whether further improvement of the USER INTERFACE design as it relates to SAFETY is necessary and practicable. 1) if yes, then the MANUFACTURER shall re-enter the USABILITY ENGINEERING PROCESS at 5.6; 2) if not, then the MANUFACTURER shall: i) document why improvement is not practicable; ii) identify the data from the USABILITY ENGINEERING PROCESS needed to determine the RESIDUAL RISK related to use; and iii) evaluate the RESIDUAL RISK according to ISO 14971:2007, 6.4 | The MANUFACTURER shall analyse the data of the SUMMATIVE EVALUATION and shall identify all USE ERRORS and use difficulties that occurred. If a USE ERROR or use difficulty can lead to a HAZARDOUS SITUATION, the root cause of any such USE ERROR or use difficulty shall be determined. The root causes should be determined based on methods including observations of USER performance as well as subjective comments from the USER. |
| 5.10 USER INTERFACE OF UNKNOWN PROVENANCE (UOUP) | 5.10 USER INTERFACE OF UNKNOWN PROVENANCE | Refer to Annex C | Same | |
| 6 * ACCOMPANYING DOCUMENT | Same | Combined it to above process | ||
| 7 * Training and materials for training | Same | Combined it to above process | ||
| Annex K Evaluation of a USER
INTERFACE OF UNKNOWN PROVENANCE (UOUP) | Annex C Evaluation of a USER
INTERFACE OF UNKNOWN PROVENANCE (UOUP) | |||
| K.1 General | C.1 General | Same | Same | |
| K.2 USABILITY ENGINEERING PROCESS for USER INTERFACE OF UNKNOWN PROVENANCE | C.2 USABILITY ENGINEERING
PROCESS for USER INTERFACE OF UNKNOWN PROVENANCE | |||
| K.2.1 * Application specification | C.2.1 * USE SPECIFICATION | Simialr, Application spec was replaced by USE SPEIFICATION. | Same | |
| K.2.2 PRIMARY OPERATING FUNCTIONS | N/A | POF refer to particular standard | Same | |
| K.2.3 * Review of post-production information | C.2.2 * Review of POST-PRODUCTION information | Same | Same | |
| K.2.4 HAZARDS AND HAZARDOUS SITUATIONS caused by USABILITY problems | C.2.3 HAZARDS and HAZARDOUS SITUATIONS related to USABILITY | delete POF | Same | |
| K.2.5 RISK CONTROL | C.2.4 RISK CONTROL | Same | Same | |
| K.2.6 RESIDUAL RISK evaluation | C.2.5 RESIDUAL RISK evaluation | Same | Same | |
| K.2.7 ACCOMPANYING DOCUMENT | N/A | Combined it to above process | ||
| Summary | New added UOUP should follow the Annex K to be evaluated. | Delete Frequently used functions and POF identification，merge them to USE SPEIFICATION. The HAZARD-RELATED USE SCENARIOS identification is important during the Usability engineering process. Detail Formative and Summative EVALUATION | Refer to the latest revsion of ISO 14971 and add more requiements about the summative testing, such as the user group and use difficulty. |
来源：包总
