There are a lot of great reasons why your digital-physical device might benefit from a touchscreen display. Digital interfaces can be more intuitive, powerful, and scalable — assuming good interaction and user experience design, of course. For applications requiring significant levels of information, feedback, and interactions, there may be no alternative.
At Bresslergroup, we design lots of devices with digital interfaces. A frequent question we get from clients is, What kind of touchscreen display is best for our product?
If you’re at the beginning of your product development process and you’re not sure if your embedded device’s graphical user interface (GUI) should take the form of a custom embedded display or a commercially available, off-the-shelf (OTS) tablet or smartphone, like an iPhone, you’re not alone.
The short answer is that any of the above could work. The long answer? The appropriate choice varies by application and context of use. In this article, we’ll explain the most important factors to consider — product risk, development budget and timeline, user experience, lifecycle management, and cost of goods sold — and questions to ask yourself while you’re making this decision.
1: Have You Determined Potential Safety Risks?
For medical devices and other safety-critical applications such as transportation and infrastructure, you’ll need to consider potential safety risks and mitigations. Evaluate whether the use of an off-the-shelf phone or tablet could create an unsafe or unsecure situation during the device’s use — and if so, is it enough to point you in the direction of a custom embedded display?
For medical devices and other safety-critical applications such as transportation and infrastructure, you’ll need to consider potential safety risks and mitigations.
For example, could a liquid spill disable the display’s controls in the middle of a safety-critical medical treatment? Could pre-installed software interfere with the operation of essential performance? What’s the impact of operating system (OS) updates on commercial off-the-shelf tablets? Will the inclusion of a commercial device — like an iPad — prevent compliance with mandatory safety standards such as IEC 60601-1 for medical devices?
If your risk analysis process determines that an off-the-shelf phone or tablet does not introduce significant safety risk, then it can be evaluated against the remaining considerations below.
2: What’s Your Development Budget and Timeline?
Development budget and timelines are always a constraint — particularly for startups and lower revenue applications. Prototype user interfaces can be more rapidly developed on an off-the-shelf tablet using industry-standard communication protocols like Bluetooth, because the hardware design is complete and better software tools for quick deployment exist.
Development budget and timelines are always a constraint — particularly for startups and lower revenue applications.
For an embedded display, the mechanical design of the bezel and glass can be substantial, especially if the goal is to provide a similar look and feel to high-end consumer electronics such as the iPhone. A custom embedded display will also introduce an electronic hardware development cycle which may be accelerated by leveraging proven designs.
By contrast, design verification cycles may be shorter for a custom display. Software of unknown provenance (SOUP) and hardware/software combinations are reduced, resulting in fewer validation test cases required.
3: What Type of User Experience Are You Going For?
In addition to development considerations, embedded displays and off-the-shelf tablets have particular advantages and disadvantages when it comes to interaction design and user experience. Off-the-shelf tablets have built-in operating systems that allow designers to use existing, familiar interaction design patterns.
For example, if the tablet you choose uses an Android operating system, designers can then make use of existing interaction patterns and UI components as a way to create interfaces. While this may speed up the development process and provide users with an interface that is similar to their personal tablet, the perception of your product and the user experience it offers may leave something to be desired.
Embedded displays and off-the-shelf tablets have particular advantages and disadvantages when it comes to interaction design and user experience.
If your product requires a bespoke experience — like a combination of physical and digital buttons–an embedded display might make more sense and integrate more seamlessly with the physical design of your device. This option would also be more appropriate if your users need a more distinct interface to perform tasks. Embedded displays allow designers to “start from scratch” when designing digital experiences.
There are usually no pre-existing templates or styles from which to base your designs. This means that designers can create interfaces that are more particular and tailored to your product. This tailored approach leads to a more integrated experience with unique interactions that may instill more confidence in your users.
4: What’s Your Plan for Lifecycle Management?
The ongoing cost of supporting your device after its launch is another important consideration. While an off-the-shelf tablet may provide quicker prototype development, it can also incur ongoing support efforts with supply chain management and software development.
An off-the-shelf tablet can incur ongoing support efforts with supply chain management and software development.
Commercially available tablets are typically produced in very high volumes (millions per year) for durations of three years or less. This could create supply management issues if your device is intended to be on the market for five years or longer, as is often the case for medical devices. On the software side, a custom app running on off-the-shelf tablets may need regular modifications and testing to keep up with automatic OS updates and phone obsolescence.
With a custom embedded display, arrangements can be made with display manufacturers to ensure continued production of the same model over the product’s lifetime. The embedded software OS can also be more carefully controlled, requiring less frequent updates after initial validation is completed.
5: Have You Calculated and Compared Your Cost of Goods?
Considering desired features and anticipated sales volume, either display solution could provide the lower manufacturing Cost of Goods (COGs). For example, a tablet may be inexpensive in low volume (<100 pieces) and provide built-in features like Wi-fi and Bluetooth communication. However, as production volumes increase, the cost of custom displays may fall rapidly and will not include unnecessary add-ons such as casework, battery, camera, etc. that are included in an off-the-shelf device.
Either display solution, depending on desired features and anticipated sales volume, could provide the lower manufacturing Cost of Goods (COGs).
If the customer is expected to provide their own tablet or phone to control the device, then the cost of goods should always be lower. Consider that this approach may introduce performance reliability issues if the hardware is not closely constrained (see what happened to Apple when they released ioS 10 and it bricked some iPhones) which will drive up design validation and lifecycle support costs.
Digital-Physical Product Case Studies
At Bresslergroup, we’ve designed devices that reflect all of the available options. To read how we and our clients applied the above considerations during product development, check out these case studies:
HelmetFit’s Football Inflation System
This award-winning digital-physical product makes use of the user’s smartphone. It’s a football helmet inflation system with two components — an electric pump held in one hand (a mobile device clips into it) and an app — that communicate via Bluetooth. The project team of industrial designers and mechanical engineers explored several initial configuration options before narrowing concepts to one that leverages the user’s phone. It was determined that connecting to a phone – as opposed to integrating an LED display into the pump – has many advantages. Read more.
Bruvelo’s App Connected Coffeemaker
Bruvelo is a connected coffeemaker with a custom embedded display. The project team’s electrical engineers researched and sourced the best operating system and embedded graphics library from a minimal cost platform, and integrated the hardware and software to match the UI and the client’s cost and performance requirements. An embedded capacitive touchscreen allows flexibility to choose recipes or adjust parameters, but the primary interactions are kept relevant, contextual, and simple. Read more.
BK Ultrasound’s Sonic Window
This award-winning portable ultrasound device with a custom embedded display was new and unfamiliar for busy healthcare providers. To make sure it would fit seamlessly into their routine, Bresslergroup conducted three rounds of user research. The project team used the results of this user research to generate early concepts for combined interaction and industrial design. The result is a device whose user experience was described by one reporter as “a remote control crossed with an iPod.” Read more.
Trice Medical’s mi-eye Diagnostic Device
This medical device whose is the only fully integrated and disposable solution for the diagnosis of joint injuries. It combines a camera, a light source, and access needle in a single-use device. Its initial custom display was switched out for an 0ff-the-shelf modified Surface tablet to cut manufacturing costs, open up software options for improved UI and expand the device’s capabilities. Read more.
As a final note, remember that if you’re deciding between touchscreen displays, be sure to carefully consider product risk, development budget and timeline, user experience, lifecycle management, and cost of goods sold before making your selection. And contact us if you need help weighing your options — we’re happy to assist as you make the best choice for your product!