Hospitals have their own lighting issues of course, from the dim patient rooms to the bright task lighting. A clinician might well recognize a status symbol or know where to look for a message from experience. At home, the patient or family caregiver may use the same device with considerably less training, in rooms never intended for medical care. This could make it harder for a less experienced family caregiver to understand what to do, making the product less user-friendly for home use. Hospital care and home care are two very different environments. That is why it’s crucial when developing a device to take all possible users and environments into consideration.
The FDA guidance on home use devices asks manufacturers to consider interface visibility under a range of ambient lighting conditions and in relation to the range of users' visual acuity and their level of familiarity with the device. (Design Considerations for Devices Intended for Home Use, 2014) For the design team that means asking the question: can the intended user see and understand each cue in the interface when the device is actually going to be used? (Human Factors Considerations, 2024)
FDA guidance on devices for home use.
During a nighttime check, a caregiver may need to check on a device that is running without turning on the overhead light. Even backlighting can help keep control labels readable in a dim room, and a separate indicator can draw attention to a message that requires action.
If the device has a dimmed mode, define separate visibility requirements for routine status indicators and alerts during the design phase. A steady “Running” indicator may be readable at a lower brightness, while a “Connect to power” alert needs enough contrast to stand out when the rest of the panel is dimmed. Test both cues on the assembled prototype under typical nighttime lighting and in daylight, where reflections can make the panel harder to read. In both settings, check whether patients and caregivers can identify the device’s status and recognize when it needs their attention.
When you’re first designing the control panel, think about what a patient or caregiver needs to see at each step. If the device needs attention, a light can help them notice the message, and a short instruction like “Close the cover” tells them what to do next. Lighting can also help during setup. For example, lighting up the button the user needs for the current step can make it easier to find.
The panel layout affects how easy those cues are to understand. As you choose colors for the indicators, pair them with clear labels or symbols so users can tell the difference between “Ready” and “Needs attention.” Then, on an early prototype, light up one icon at a time and see if any of the icons next to it appear lit, too. Catching that light bleed early gives you time to adjust the spacing or change how the light is directed before you finalize the panel.
A control panel can be easy to read on an engineering bench and harder to see from a hospital bed or across a dim bedroom. During early usability testing, look at the assembled interface under a bedside lamp and near a bright window. Try viewing it from where people will actually use it, such as a patient sitting in bed or a caregiver standing beside the device. Then ask representative users to confirm that the device is running or show what they would do if an indicator changed. Watching them complete the task helps you see whether they noticed the cue and understood what it meant.
Usability testing is critical to device development, so involve your regulatory and human factors teams early. Their experience can help you determine what testing your device requires and plan for it while there’s still time to make design changes. When formal human factors validation is needed, test an interface that represents the final design with representative users performing critical tasks under realistic conditions. (Applying Human Factors and Usability Engineering to Medical Devices, 2026)
For medical device manufacturers, it's much easier to judge backlighting, indicators, and illuminated controls when the interface is still being designed. Lumitex works with OEMs to develop and prototype lighting around the controls, viewing conditions, and available space. Whether you're taking an existing clinical device and adapting it for the hospital room, for home care, or you're designing a new device from scratch, we can help you to make the information that patients and caregivers need far easier to find. Take a look at Lumitex's medical HMI lighting solutions for information or contact us.
(2014). Design Considerations for Devices Intended for Home Use. FDA Guidance Document. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/design-considerations-devices-intended-home-use
(2024). Human Factors Considerations. FDA. https://www.fda.gov/medical-devices/human-factors-and-medical-devices/human-factors-considerations
(2026). Applying Human Factors and Usability Engineering to Medical Devices. FDA. https://www.fda.gov/regulatory-information/search-fda-guidance-documents/applying-human-factors-and-usability-engineering-medical-devices
What should the manufacturer consider when adapting a hospital device for home use?
Consider who will use the device, where they'll use it, and how much training they'll have. A family caregiver may be looking at the device for the first time in a dimly lit bedroom. They need to tell whether the device is on, know when it needs attention, and find the right controls.
How can a medical device display be readable in both a dark room and in bright daylight?
Check the assembled interface in both settings. In a dim room, check that the control labels are legible and that the alerts still pop out when the panel is dimmed. In daylight, check for reflections from a nearby window and view the display from the angles a patient or caregiver would actually use.
How can lighting be used to help the user know what to do next?
Use light to draw attention to the relevant control or message. If the cover is open, for instance, an illuminated indicator could draw attention to a short instruction such as "Close the cover". Always pair a color cue with a clear label or symbol, so the user has more than one way of knowing what the device is telling them.
What is a light bleed, and why does it matter on a control panel?
Light bleed occurs when light from one indicator spills over into a neighboring icon and makes it look active. On an early prototype, you can turn on one indicator at a time to see whether adjacent ones light up. That gives the design team a chance to adjust the spacing or how the light is directed.
When should lighting be assessed during medical device development?
Start with an early assembled prototype whilst you still have the chance to change the panel. Ask representative users to carry out a simple task (e.g. confirm the device is running or confirm receipt of a message). Watching them use the interface will show whether they pick up the cue and understand what to do afterward.