Human Error and User Interface Design

Violations can be particularly hazardous when they are combined with error. The violator knows that he is acting incorrectly and is therefore more likely to hide his/ her behaviour. 

Usability is the characteristic of the user interface that establishes effectiveness, efficiency ease of user learning and user satisfaction [11]. Usability impacts not only safety but productivity, user fatigue, user take-up, customer acceptance and satisfaction. Poor usability of HIT is widely believed to have a substantial negative effect on clinical efficiency and data quality [12]. 

Many industries including nuclear engineering, aviation and the military have come to realise that human-system interaction can have a major impact on safety. In these domains regulatory processes have been put in place to mandate usability evaluation. Both the US FDA rules and Europe s Medical Device Directive require manufacturers to undertake usability studies (see Sect. 4.2.7). Even for products outside of medical device regulation, the contribution of usability issues to patient 

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Computer systems validation personnel must also deal with design errors. A program that perfectly meets a lousy specification is a lousy program. Specifically for medical devices, books on software reliability tend to set aside the user interface issue, and treat it as the sole province of the human factor analyst. The reliability of a system is determined by how all its various parts, including the people who use it, work together. 

Some passive controls will live outside the user interface and may not be apparent to day-to-day operators. For example, HIT systems typically need to exhibit resiliency in their architecture whether brought about through redundancy or other systematic means. These design features represent active engineered controls. However it is common for this to be supported by other more passive controls which require some degree of human intervention. The platforms on which systems reside can often be monitored for availability and performance. In some cases systems may be specifically instrumented to provide metrics on the execution of specific functions or the success of database transactions. Similarly systems may log errors or failed messages which are then made available for inspection by service management personnel. 

Continued acknowledgment and improvement in device human factors—especially as they apply to the device-user interface. As devices become increasingly human-friendly and their operation more intuitively obvious, the consequence of use errors is minimized, and patient injuries and deaths are also reduced. One of the best ways of assessing the human factors associated with device design is still done through prepurchase evaluations performed within the user s actual clinical environment. Here, the Agency for Healthcare Research and Quality also recommends ... 

The verification of the operator-initiated SiF shouid consider the potentiai for operator error using user-approved criteria or anaiysis techniques. This assessment shouid inciude the human interface design and operating procedures. 

Abstract. When the reqnirements and the interaction design of a system are separated, they will most likely not fit together, and the resulting system will he less than optimal. Even if aU the real needs are covered in the requirements and also implemented, errors may he induced hy human-computer interaction through a had interaction design and its resulting user interface. Such a system may even not he used at aU. Alternatively, a great user interface of a system with features that are not required will not be very useful as well. 

A wide variety of human errors can occur during the use of the software. Typical examples of this type of errors include misunderstood prompt, misunterpretation of documentation,. ..etc. Preventing these errors requires the involvement of Human Factors in the early design and analysis of the system software. This includes the development of design requirements, recommendation and guidelines, particularly with respect to the user interface. 

The design should take into account the possibility of human error—both errors of omission and errors of commission — on the part of the system s users. To minimize the likelihood of serious adverse consequences resulting from user errors, the human-machine interface should, to the extent possible, be structured in design such that single errors on the part of the operator are inconsequential and are detectable and correctable. Simations in which human error has both a relatively high likelihood of occurrence and major adverse consequences should be avoided by means of a suitable system structure or design of the user interface, or by automation. 

Man-Machine Interfaces Another important consideration in machines and equipment is the interface with users. Ergonomics or human factors engineering principles are often critical in the design of machines and equipment. There are many opportunities to improve productivity and reduce errors in operations that may result in accidents by understanding the visual, auditory, tactile, physical, and mental processing capabihties and Hmitations of people. One must also recognize that many variables in people can affect performance of machines and equipment. 

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