What is ambient safety?
A guide to safety that is built into the room instead of worn on the body or watched through a lens: what the idea means, why it matters in care and at home, which technologies deliver it, and what it does not promise.
Published by Stillsense · Sources reviewed
Ambient safety in one paragraph
Ambient safety is protection that comes from the room itself, not from something a person wears or a camera that watches them. Sensing in the environment notices presence, movement and unusual events, and tells the right person when something looks wrong, without the person at risk having to do anything. It is the term Stillsense uses for this approach. Closely related established terms are ambient assisted living (AAL) and passive monitoring, and in Norway velferdsteknologi (welfare technology) and digitalt tilsyn (digital supervision).
Why safety should not depend on a button
The personal alarm has been the standard answer to living alone for decades: press the button and help comes. It only works if the person is wearing it and is able to press it. In a cohort study of people over 90, published in the BMJ in 2008, 30% of those who fell had lain on the floor for an hour or more, and call alarms were widely available but were not used in most of the falls that led to a long time on the floor. Those findings describe the study, not Stillsense.
Cameras solve the button problem and create another. They can notice a fall without anyone asking, but few people want a lens in their bedroom or bathroom, which is where many of the hardest moments happen.
Ambient safety starts from a different question: can the home notice that something is wrong, without the person being watched or asked to do anything?
What makes safety ambient
The word describes how the protection is delivered, not one particular device. A system is ambient when:
- There is nothing to wear, charge, remember or press.
- It records no image and no sound.
- It covers the space people live in, not a single spot or a cone of view.
- It stays quiet by default and speaks up only when something needs attention.
- It leaves the daily routine of the person untouched.
The technologies behind it
Ambient safety is not tied to one sensor. Passive infrared motion sensors, bed and door sensors, thermal sensors, mmWave radar and Wi-Fi sensing are all used, alone or together. They differ in what they capture, how many devices a home needs and what they miss.
Stillsense uses Wi-Fi sensing, which reads how the Wi-Fi signals already in a building change when people move.
What is Wi-Fi sensing?Where ambient safety is used
In nursing homes, it supports night supervision: knowing that a resident has left the bed, or has not returned to it, without opening the door and waking them. In home care, it adds awareness between visits for people who live alone. In family homes, the same sensing tells the house that someone is present, which is also what heating and lighting need to know.
In Norway this sits inside municipal welfare technology. The Norwegian Directorate of Health tracks digital supervision (digitalt tilsyn) as one of the welfare technologies municipalities report on, alongside location technology and electronic medication support.
What ambient safety does not promise
A room that notices is only useful if someone responds. Ambient safety is a way of knowing sooner; it does not replace people, and it is not a guarantee.
- An alert needs a responder. Who receives it, and what they do, has to be agreed before the technology is switched on.
- Detection is never perfect. Missed events and false alerts both happen and should be measured in the real setting.
- No image does not mean no personal data. Patterns of presence and activity need consent, access control and limits on retention.
- It complements a personal alarm and existing care routines. Whether it can replace any of them is a decision for the care provider, based on evidence.
How Stillsense approaches ambient safety
Stillsense turns the Wi-Fi already in a building into the sensing layer. A small sensor reads the signal, the interpretation happens on the device in the home, and an alert goes to the person who should know. There is no camera and nothing to wear.
We state the maturity of each capability and keep the list public, including the parts that are not finished.
Stillsense for care servicesCommon questions about ambient safety
- Is ambient safety the same as ambient assisted living?
- They overlap. Ambient assisted living (AAL) is the broader research and engineering field of technology that supports independent living. Ambient safety, as Stillsense uses the term, is the narrower goal within it: noticing when someone may need help, without cameras or wearables.
- Does ambient safety replace a personal alarm?
- Treat it as a complement. A personal alarm lets a person call for help on purpose; ambient sensing can notice when they have not, or cannot. Whether one can replace the other should be decided by the care provider on the basis of evidence from the actual setting.
- Does ambient safety need cameras?
- No. Some digital supervision uses cameras, but ambient safety as described here relies on sensing that produces no image and no sound, such as Wi-Fi sensing or radar.
- Who receives the alert?
- That is set up per deployment: night staff in a nursing home, a home-care service, or a family member. The response arrangement matters as much as the detection, and should be agreed first.
- Is Stillsense validated for fall detection?
- Not yet independently. Fall detection is available, and independent validation is planned but not yet underway. Until then it is not a safety-grade guarantee, and care routines should be built on presence, motion and bed-exit.
Sources and method
This guide is written by Stillsense. "Ambient safety" is our term for the approach; it is not a formal standard or a regulated product category. The research findings and the description of Norwegian welfare technology come from the sources below, reviewed on the date shown, and describe the sector, not Stillsense results. Statements about Stillsense reflect our product documentation and current testing status.