A pendant only works if it is worn and pressed. A motion sensor in a hallway sees a hallway. A camera sees everything, which is exactly the problem in a bathroom. A radar sensor sees movement through the dark but cannot tell you why someone is on the floor.
None of that is obvious from a product page, and most of it decides whether a system helps or just generates alerts nobody trusts. These pages are about the sensors, not the brands: the buying decisions live in Comparisons, and the products themselves in the directory.
Key facts
- A sensor senses one thing and reports another. Heat, sound, radio waves, pressure, images, or a button being pressed — and what it tells you is an inference drawn from that, not the thing itself.
- Every sensor has a failure mode, and where it fails decides which room it belongs in. Bathroom, bedroom, hallway, front door and stairs all ask different things of a sensor.
- Not everything stays in the house. Whether anything is recorded, where it is processed and where it is stored varies by product, and it is rarely on the box.
- Most room radar sold for this purpose is a licence-exempt field disturbance sensor. Innovation, Science and Economic Development Canada's RSS-210 covers "devices operating in the band 57-71 GHz" and defines a field disturbance sensor as one that detects "changes in a radio frequency field as a result of movement of persons or objects" (ISED, RSS-210, checked September 2026). Movement of a person or object is the whole of what the radio part does.
Every sensor type, and the products that use it
Each page explains the sensor type first and lists the products second, with every attribute sourced and dated:
- Radar presence sensors — presence, movement and prolonged stillness room by room, no camera, nothing to wear
- Radar fall-detection sensors — the wall and ceiling units that claim to detect a fall without a wearable, and what the evidence does and does not show
- Wi-Fi sensing — reading how a body disturbs the signal between a router and its devices
- Acoustic monitoring — what a microphone in a resident's room hears, what it misses, and the privacy question it raises
- Indoor cameras with AI — what video and software can and cannot tell you, and where a camera cannot go
- Medical alert pendants and watches — the help button and the automatic fall-detection claim, and the wear problem
- Smart speakers and voice assistants — what a far-field microphone is actually for
Start from the room, not the brand
- The bathroom. The room where a camera is least welcome. PIR vs mmWave radar vs Wi-Fi sensing vs acoustic sets the four options against each other.
- The bedroom and the night. Darkness rules out anything that needs light. What matters is whether the sensor can tell a still, sleeping person from an empty room.
- The hallway and the front door. Movement between rooms is what shows a routine changing, and it is the thing the simplest sensors are best at.
- You have been shown a specific product. Find the page for the sensor inside it, and read the failure section before the feature list.
- The question is really privacy, not capability. Then the page you want is edge vs cloud, which is about what leaves the house at all.
Room-by-room is also why the plug-in radar units in this category are sold one per room rather than one per home: the reporting area of each one is the room it is standing in, so four rooms is four units, and a room with no unit in it is simply not covered.
Text description of this diagram
Plan view of a flat with four rooms — living room, hall, bedroom and bathroom. A small plug-in unit sits low on a wall in each room, and the shaded area each unit reports on fills that room and stops at its walls.
One page per sensor
How it senses, what it reports, where it fails, and which room it suits.
- What is a mmWave radar sensor, and why it can go where a camera can't
- Is mmWave radar safe? Power levels in a bedroom, in plain numbers
- Acoustic monitoring in care homes: how it works, what it hears, what it doesn't
- Bed alarms and bed sensors: types, and when a room sensor is better
- How a system learns a daily rhythm (and why offline is not the same as no movement)
- Edge vs cloud: what leaves the house and what doesn't
The directory records what each product publishes about itself, including the sensor classes without a page of their own here: PIR motion sensors, door and contact sensors, Wi-Fi sensing, indoor cameras and AI video, wearables and pendants, daily check-in apps, medication dispensers, and GPS and wandering devices.
The terms these pages use — mmWave, PIR, presence versus occupancy, prolonged stillness, edge versus cloud — are defined in the glossary.
In this section 6
Acoustic monitoring in care homes: how it works, what it hears, what it misses
How acoustic monitoring works in care homes, what the sensor hears, what it misses, what the evidence really shows, and the privacy questions to ask in Canada.
Read →Activity pattern monitoring: how it learns a daily rhythm, and why offline is not a quiet room
How elderly activity pattern monitoring learns a daily rhythm, how long it takes, what a changed pattern means, and why a sensor going offline is not a quiet room.
Read →Bed alarms for elderly people: the five types, and whether they prevent falls
Hospital trials found bed alarms alone did not cut falls. The five types of bed alarm, what each misses, and when a quiet room sensor is the better tool.
Read →Edge vs cloud: what leaves the house and what doesn't
Edge processing for home sensors, explained for families: what cameras, acoustic monitors and radar sensors send out, what Canadian privacy law says, and what to ask a vendor.
Read →Is mmWave radar safe? Power levels in a bedroom, in plain numbers
Is mmWave radar safe or dangerous? Canada's Safety Code 6 limit, what a room sensor is allowed to transmit, and a worked example for a bedroom wall, with sources.
Read →What is a mmWave radar sensor, and why it can go where a camera can't
A plain-English guide to mmWave radar sensors in elderly care: how they work, what they can and cannot tell you, Canadian rules, and what the evidence says.
Read →
What they cannot do
No sensor described in this hub knows that someone has fallen. Some infer it, some claim it, and the claims vary in quality. Where a vendor claims fall detection, we quote the claim in their words and say whether they publish accuracy data; we do not test the products and we do not endorse or dispute the claims.
Where WalledCare fits
WalledCare is one of the sensors described here: millimetre-wave radar, no lens and no microphone, plugged into a wall outlet, one unit per room. It reports presence, movement, prolonged stillness and prolonged inactivity, room by room. Because there is no lens it can go in a bathroom; because there is nothing to wear, charge or press, none of that depends on being remembered. It does not detect falls, does not measure breathing, and is not a medical device. If detection of the fall itself is what you need, a pendant or a monitored medical alarm is the honest answer, and both are listed in the directory.