Sean Hägen, founding principal, BlackHägen Design, considers the nuances in the aesthetics of medical device design.
You can put lipstick on a pig, but it is still a pig.
If you are not familiar with this phrase, it means creating superficial changes to a product design in a futile effort to disguise its fundamental failings. This article addresses the importance and challenges in the relationship between medical device development and the aesthetic design process. Moreover, how the appropriate aesthetic can be much more than cosmetic, it can improve ease-of-use, use-safety, and delight. These are critical to the success of a medical device or system. To achieve a purposeful aesthetic that impacts critical aspects of the device, it requires a rigorous methodology appropriate for medical device development. A cross-functional approach utilising Perceived Attributes, Affordances and Product Semantics can not only inform better requirements but ultimately result in more meaningful and appropriate product aesthetics.
Introduction
Medical device manufacturers are typically focussed on developing and commercialising their core technology to meet the needs of the healthcare industry and differentiate themselves from their competitors. Quite often the development of their technology is the foundation of the company. For this reason, it is common that the user experience, specifically the aesthetics, of a medical device is a lower priority, or even an afterthought. However, there are cases, where the appearance of the design may be a higher priority when driven by marketing for important commercial objectives. The relationship between marketing and engineering can become conflicted when developing the aesthetic and user experience diverts time and resources from the engineering of the technology.
The focus of these challenges is often manifested in the device’s requirements. There are many types of requirements, marketing, system, user interface, and product requirements, for example. The variations in these are typically a function of the company’s quality system and at what point in the development process they are established. Even though designers are rarely involved in the direct development of the requirements, they are often caught between the priorities of marketing and engineering; resulting in a role of bridging the two potentially contentious priorities.
There are exceptions where some companies utilise their designers in research roles prior to formal product development. In these cases, the designers may be responsible for generating inputs to the requirements. Although this may provide the designers intrinsic insight to enable them to better bridge the needs and expectations of marketing and engineering, it doesn’t necessarily rationalise the characterisation and relevance of an appropriate aesthetic. This is where usability engineering (UE) or human factors engineering (HFE) comes into the process.
Perspectives in aesthetics
Research by HFE has documented the nature of a user’s choices and behaviours as being significantly influenced by the aesthetics of product. This insight illuminates the potential impact aesthetics can have on ease-of-use as well as use-safety. These two characteristics of a device have an influence on requirements from different perspectives and different stakeholders. Ease-of-use and delight impact the design from the perspective of commercial objectives, marketing being the lead stakeholder initially and it may be shared by Industrial Design (ID), User Experience (UX ) design and UE later during development.
Use-safety impacts the design from the perspective of regulatory objectives, engineering being the lead stakeholder. However, the engineering stakeholders for regulatory objectives are not necessarily the same as those focused on technology. Use-safety is the responsibility of UE/HFE, which may be initiated as part of system engineering or implemented as part of quality engineering (the former being more likely to be proactive since their influence is early in the design development process).
These two perspectives highlight the deficiency of an umbrella requirement like, “the device should be easy to use,” as not having nearly the specificity to be implemented properly and validated affectively. Technically, it doesn’t address use-safety, though likely that wasn’t purposeful. In fact, ease-of-use and use-safety are commonly opposing criteria when it comes time to implement. The harmonisation of these objectives in a design can be a significant challenge that can be addressed by the initial impressions enabled by aesthetics.
An important point is that requirements typically need a good deal more elaboration and then, will likely need to be divided into multiple, more directed requirements. Not that you want to describe how to meet the requirement -- that is for specifications -- but you want to achieve more detail. For example: “The user should be able to power on the device without instruction.” Realising this sounds like an obvious expectation, it is surprising how many homemade labels are on medical devices to instruct the user how to turn it on.
It should be noted the regulatory perspective regarding “user error” and “use error” are significant. This is substantive in understanding usability. From the perspective of the FDA, it is not the user’s fault if, during the use of a device, they commit an error or action not intended by the user or manufacturer. Instead, it is the responsibility of the product manufacturer to design out the potential for error and to validate the design controls are effective. Therefore, there is not user error, there is just use error. In other words, the manufacturer cannot be responsible for the clinical skills of the user, but they are responsible for the user interface of their product and its ability to minimise use error.
Discussion
Regardless of how the process is executed, design needs enough fidelity in the requirements that influence the aesthetic (beyond corporate identity), to address subjective attributes such as “intuitive” and “easy.” To design in a systematic manner for a user’s first impression and subsequent assessment of a system to have a purposeful meaning, there are two key factors to inform the design process, initial user perception and context of use (which includes user needs). A process for characterising and prioritising that can support this effort is called Perception Attributes.
Utilising Perception Attributes characterises the value relationship with the intent to influence the user’s decisions regarding the utilisation of a device. In the healthcare space the design team must consider all perception attributes while also focussing even further on highly specialised use case scenarios. Ultimately, the user’s assessment is based on their perceived Value because of the interconnection of Function and Appearance.
Prioritising and expanding upon Perception Attributes and articulating what is applicable in the explanation of requirements, can guide in the development of the appropriate Product Semantic. Specifically, requirements that ultimately provide design guidance to develop Affordances that enable the user to intuitively experience their expected outcome, such that the interactions are self-evident.
The ID theory and methodology of Product Semantics not only relates to aesthetic design attributes, but harmonises them into a cohesive, repeatable methodology. The HFE theory of Affordances explains the psychological mechanism for what an object affords a subject. More specifically considering how objects afford, for whom, and under what circumstances. An affordance is a relationship between the properties of an object and the capabilities of the user that determine how the object is interacted with and what is the potential outcome of the interaction.
The application of Perceived Attributes methodology can connect the two theories of Product Semantics and Affordances into a cohesive approach that enables a meaningful aesthetic that harmonises the requirements of all the stakeholders.
A goal of the product semantics approach, in the healthcare space, is to enable a self-evident user interface through the qualities of the device’s aesthetic, form, shape, texture, colour and metaphor. The aesthetic composition of a design does not literally explain what it does, rather, it is how the user interprets it.
User evaluation studies, conducted by UE, typically identify tasks that have usability issues and many of those are characterised as not “intuitive,” requiring the design to be more resilient and “user friendly.” Those user evaluations are purposely designed so that the participant is not coached on how the device operates to expose usability issues and, by default, demonstrate intuitiveness. When the UE analyst reports on the usability issues, there is language used to describe the deficiencies and/or infelicities. These can be starting places for the perceived attributes that inform the product semantics.
A meaningful aesthetic that communicates function is most critical for a medical device during initial appraisal, and beyond -- to aesthetic judgment. That is, from the visceral impression to the entirety of the user experience. It requires the design team to understand the context of use, including the use-related risks, to prioritise how user-needs translate into aesthetics, and affordances.
This circles back to the harmonisation between use-safety, ease-of-use, and delight. Often the driving requirements conflict, therefore it is essential to have a thorough understanding of the contextual origination of the needs that informed the process. Also, insights based on observation of users and their context of use should identify potential positive and negative transfer bias that the designers must consider when characterising the attributes of the design language. “An object’s form first says something about the object itself, then secondarily something about the larger context of its use; both to the user who interacts with it and to the designer that develops those conceptual connections,” (Krippendorff, K., & Butter, R. (1984).
Conclusion
The relationship between medical device development and the process of documenting, then translating requirements can have a profound and purposeful influence on the design process that results in the final aesthetic. Furthermore, the methodical development of the appropriate aesthetic can be much more than consequential cosmetics, it can improve ease-of-use, use-safety and delight -- by design.
Through methodologies that utilise developing the appropriate aesthetic through the process of exploring the intended Perceived Attribute, user interface Affordances and Product Semantics, designers can demystify complex technology, improve intuitive user interaction, and harmonise use-safety and ease-of-use. In summary, the process is as follows:
- Understand the user needs, usability issues and current biases.
- Establish what the Perception Attributes are from the user’s perspective.
- Collaborate on the development of requirement inputs with a vernacular based upon the Perception Attributes.
- Translate Perception Attributes and subsequent requirements into user interface affordances.
- Develop a product semantic schema that provides an aesthetic which accommodates the affordances.
- Interpret the semantic schema into design proposals.
- Evaluate the design proposals with users.
