Usability Evaluation and Assessment of Computed Tomography Scan

Usability is a vital characteristic in operating medical machines, especially radiological machines, such as computed tomography (CT) scans and X-rays. The more the body is exposed to it, the greater the negative effect has. If usability is crucial to a specific industry, it is more crucial in the medical health industry due to its tremendous effect on safety and the patient’s health. This study examines the usability of CT scans based on 14 attributes from hospitals across Saudi Arabia. The study revealed that usability consistency, visibility, minimalism, memory, and flexibility have the most usability catastrophic complaints, where the overall catastrophic rate exceeds 20%. Creating a shortcut for frequently used operations is critically important, because it has a fundamental effect in minimizing physical and mental exertion.


Introduction
The usefulness of medical devices is marked by the extent to which they can execute tasks effectively, effortlessly, and easily.Advances in science and technology have made executing tasks increasingly complex.It requires years of learning and practice to efficiently operate modern medical devices, such as computed tomography (CT) scans or magnetic resonance imaging (MRI) [1].A key contribution to such complexity is the fact that contemporary systems consist of multiple layers with extreme compatibility and intractability.When constituting a multi-layer system based on safety and security only, it becomes negative goals.
Rather, it should constitute more layers to achieve overall functionality [2].
Moreover, [3] showed that the overall expectation of CT scan technological evo-S.Aldoihi, O. Hammami DOI: 10.4236/iim.2020.12100228 Intelligent Information Management lutions is to make the CT scan a more usable with a better user-friendly interface; however, the study showed that more technological evolution introduces increased complexity.
The general assumption for medical devices is that they ought to be usable and suited for their purpose [4].To efficiently operate a CT scan requires adaptability with other systems, such as radiology information systems (RIS) or picture archiving and communication systems (PACSs).These systems integrate with a superior ecosystem called the hospital information system (HIS).The purpose of the HIS is to collect all patient records and make them retrievable by many of the hospital's applications [5].Therefore, a CT scan operation is one component of an ecosystem.This isolated component has a tremendous effect on the overall ecosystem, and most importantly, it has a great effect on the indirect user (patient).
This paper will contribute to the general understanding of CT scan usability.
Particularly, it explicitly focuses on technicians from Saudi Arabia.It observes and documents the usability encountered by technicians and provides recommendations to manufacturers and designers.The paper is structured as follows.
Section 2 discusses the reality of the context of use within the operation of radiology.Section 3 discusses the study justification and objective.Section 4 details the methodology approach.Section 5 presents the results.Finally, Section 6 concludes the paper.

Context of Use
In general, usability is extremely essential to buyers because it brings certain benefits and, above all, contributes to maximizing safety.Furthermore, in the healthcare environment, usability is crucial because it contributes to safety and the prevention of errors.To [6], usability revolves only around the user, where the user should be involved, engaged, and doing something within the context of the product or system.Working in the healthcare environment makes one susceptible to extreme physical and mental loads as well as industry guidelines and requirements.Furthermore, [7] noted that usability is an essential attribute of safety.Thus, many industries tend to share this attribute [8] [9] [10].
Eventually, the context of use can be measured by calculating influential factors that affect (positively or negatively) the functionality of the product or users.
The context of use covers a wide context of an organization's geopolitical atmospheres, such as requirement components and fitness for use (Figure 1).The workload can also negatively pressure the context of use.In addition, [11] has shown that the invisible workload can tremendously affect the working process of the CT scan operation.It was evident that radiologists seek minimal effort to divert invisible physical exertion after a certain operational time.Thus, radiologists maneuver the CT scan testing process so that they can avoid roving back and forth between the CT scan and the control room [12].

Study Objectives
Most usability evaluations that targeted healthcare in Saudi hospitals tend to discuss the obstacles of introducing new technologies.Nonetheless, literature progress that offers a sense of solution has been extremely limited.One fundamental reason is that many researchers have adopted their methods and evaluated attributes from a pure software perspective.It is fundamentally essential to examine and evaluate healthcare products based on the context of use and, in particular, involving the direct user (technician) and indirect user (patient) together.This study closely examines 14 usability attributes of the CT scan in Saudi hospitals.It also classifies the usability attributes based on severity.Understanding such severity is expected to help CT scan designers and manufacturers to improve future products to suit a specific market.In addition, the fundamental aim of this study is to explain the user's demographic differences where gender, age, education, and experience pose a threat in handling and operating the CT scan.

Method
To answer the research questions, a survey questionnaire was adopted.The research questions are 1) What usability attribute is deemed important to CT scan technicians?2) What usability attribute do technicians have the most trouble with?

Procedure
The authors surveyed usability questionnaires that measured the lack of usability from different angles.The authors chose to adopt [4] because it was unambiguously intended for medical device use.The questionnaire measured 14 usability dimensions (Table 1).The responses to the questionnaire are based on a five-point Likert scale.Prior to the start, we conducted field observations in King Saud Medical City (KSMC).During the observation, the first author evaluated the operational usability in association with the everyday use and the applicability of the questionnaire to the CT scan context of use.The results were analyzed using SPSS 24.Intelligent Information Management Table 1.Usability attributes as defined by [4].

Consistency
Consistency and standards: Users should not have to wonder whether different words, situations, or actions mean the same thing.Standards and conventions in product design should be followed.

Visibility
Visibility of system state: Users should be informed about what is going on with the system through appropriate feedback and display of information.

Match
Match between system and world: The image of the system perceived by users should match the model the users have about the system.
Minimalist Minimalist: Any extraneous information is a distraction and a slow down the process.

Memory
Minimize memory load: Users should not be required to memorize a lot of information to carry out tasks.Memory load reduces the users' capacity to carry out the main tasks.

Feedback
Informative feedback: Users should be given prompt and informative feedback about their actions.

Flexibility
Flexibility and efficiency: Users always learn, and users are always different.Give users the flexibility of creating customizations and shortcuts to accelerate their performance.

Message
Good error messages: The messages should be informative enough such that users can understand the nature of the errors, learn from the errors, and recover from any errors.

Error
Prevent errors: It is always better to design interfaces that prevent errors from happening in the first place.

Closure
Clear closure: Every task has a beginning and an end.Users should be clearly notified about the completion of a task.

Undo
Reversible actions: Users should be allowed to recover from errors.Reversible actions also encourage exploratory learning.

Language
Use the users' language: The language should be always presented in a form that is understandable by the intended users.

Control
Users in control: Do not give users that impression that they are controlled by the systems.

Document
Help and documentation: Always provide help when needed, ideally context-sensitive help.
The authors received ethical approval from the Ministry of Health in Saudi Arabia and satisfied the requirements of dealing with a human as an object of research.

Participants
Even though radiology technicians are able to operate many radiology machines interchangeably, such as CT scans or MRIs, the study only focused on technicians who were using the CT scan on a daily basis at the time of the study.The total number of participants was 44 CT scan technicians (Table 2 shows demographic characteristics).The technicians were geographically from hospitals in all 13 Saudi regions.

Results
Cronbach's alpha was conducted to measure the reliability of the questionnaire S. Aldoihi, O. Hammami DOI: 10.4236/iim.2020.12100231 Intelligent Information Management (Table 3).Generally, Cronbach's alpha is acceptable when the value is above 0.80 [13].All attribute scores were above the acceptable level of 0.80.In terms of usability catastrophe, all attributes have a usability catastrophe percentage.
However, seven usability attributes exceeded the 20% range:  • layout and position, • terminology, • current state of the system, • what can be done at the current state, • progressive levels of detail at 20%, • concrete examples at 20%, and • shortcuts for frequently used operations at 27.3%.
These attributes belong to consistency (two attributes), visibility (two attributes), minimalism (one attribute), memory (one attribute), and flexibility (one attribute).Table 4 illustrates the descriptive statistics for all usability attributes.Evidently, the maximum statistic registers as 4, which is a catastrophe for every attribute.This indication shows that users have varied abilities in handling the CT scan.These variations are in accordance with social demographic characteristics.The statistic means were examined, where the uppermost is 2.34, and the lowermost is 1.55.Figure 2 presents the overall usability score based on the 14 usability attributes.A higher number indicates more usability issues faced by the technicians.As a group, most of the issues were concentrated within the categories of document (56.5%), flexibility (56%), and visibility (55.5%).

Figure 1 .
Figure 1.Context of use within the CT scan operation.