Glossary: AI rings, voice assistants and home robots explained

AI agent: An AI that can act with tools, such as sending a reply or moving a meeting, not only answer. What an AI agent is.
AI ring: A ring that connects you to an AI assistant. Some record voice notes for an app on your phone; assistant rings answer on the ring itself. What is an AI ring?
Battery life: How long a device runs on a charge. Health rings are rated at around a week; rings with a mobile connection of their own last less. Smart ring battery life.
Bluetooth LE Audio: A newer kind of Bluetooth sound that uses less energy. Earbuds that support it can play a ring’s answers. What LE Audio is.
CE marking: The mark with which a manufacturer declares that a product meets the EU rules that apply to it; not an approval by the EU. Lychnos Ring and Alkyon are in development and not yet CE marked. What CE marking means.
Concept render: A picture of a design made by computer, not a photograph of a finished product.
Consent to record: In many European countries, recording other people’s private conversations needs their consent; in Germany, doing it without is a criminal offence. Recording conversations with an AI wearable.
Digital euro: Money the European Central Bank is preparing to issue in digital form, alongside cash: free for basic use and usable offline. A first issuance could come during 2029 if EU law is adopted first. The future of payments in Europe.
Do Not Disturb: A phone mode that silences calls and notifications, with exceptions you choose, such as a few people or a second call within minutes. Letting family through.
Dock: Alkyon’s home base, where it lands and charges, and where Lychnos Ring charges on its peg. A concept. A dock that swaps the battery.
Dumbphone: A basic phone for calls and texts, without apps or feeds, chosen to use the phone less. What you lose, and how to cope.
eSIM: A SIM built into a device and set up by download instead of with a card. What is an eSIM?
FCC ID: The identifier on a radio device that has been through the US FCC’s certification: a code for the company and one for the product. Lychnos Ring has not been authorized yet. What an FCC ID means.
General wellness product: The US FDA’s term for a low-risk product meant only to support a healthy lifestyle, which it does not review as a medical device. Since January 2026 it can include non-invasive estimates such as blood pressure or glucose, without disease claims or medical alerts. Where the line runs.
Ground effect: The extra lift a rotor gets close to the floor. Near a ceiling a rotor gains lift as well, so a small drone tends to rise towards it. What moving air does to a small drone.
Haptics: Feedback you feel, such as a buzz. Lychnos Ring gives each kind of answer its own pattern of buzzes.
Heart rate variability (HRV): The variation in time between heartbeats, shown by many wearables as RMSSD; best compared with your own baseline. What HRV is.
Hold to talk: A button you hold while you speak; the microphone works only then. Hold to talk versus wake words.
IP rating: A code from the IEC 60529 standard for how well a device keeps out dust (first digit) and water (second digit), such as IP68. IP68 or 5 ATM?
Kalman filter: A method that blends noisy sensors into one better estimate, used in phones, drones and spacecraft. What a Kalman filter is.
Large language model: The kind of AI behind chatbots: trained on vast amounts of text to predict what comes next. What a large language model is.
LTE-M: A mobile network for small devices that send a little data and must last on a small battery. What LTE-M is.
No-go zone: An area a home robot must not enter, marked on its map.
NPU: A neural processing unit: the part of a chip built for the arithmetic of neural networks, so AI can run on the device. What an NPU is.
Object detection: Software that finds things in a picture and labels them, such as a person or a cat, with a score for how sure it is. How object detection works; how we trained ours: cats, dogs and tulle.
Optical flow: How fast the picture moves across a camera. A drone looking down at the floor uses it to measure its own speed. What optical flow is.
Orthosomnia: A preoccupation with perfecting the sleep data from a tracker, which can make sleep worse; named by sleep researchers in 2017. When a sleep tracker keeps you awake.
Payment token: A stand-in for your card number that your bank issues for one device, such as a phone, a watch or a ring, so shops do not see the real number. How tap to pay works.
Prompt injection: Instructions hidden in a web page or an email that try to make an AI agent do something its user did not ask for.
Propeller guard: A ring or cage round a propeller that keeps fingers and fabric away from the blades. Propeller guards a finger cannot pass.
RAG: Retrieval-augmented generation: an AI looks things up first and answers from what it found, so it can cite sources. What RAG is.
Reinforcement learning: Learning by trial and error from rewards, as game-playing programs and some robots do. What reinforcement learning is.
Ring size: A number or letter for the inside of a ring: US sizes, EU sizes in millimetres, UK letters. Ring size calculator.
See-through display: A screen you can hardly see when it is off. Lychnos Ring’s is 72 by 40 pixels. A smart ring with a screen.
Signal-to-noise ratio (SNR): How much louder the sound you want is than the noise around it, usually in decibels; the lower it is, the harder speech is to recognise. Voice assistants in noise.
SLAM: Simultaneous localisation and mapping: a robot drawing a map of a place while working out where it is on it. What SLAM is.
Smart ring: A ring with electronics inside, most often for sleep and health, sometimes for payments or for your voice. Smart ring or smartwatch? All our guides: smart rings.
Speech recognition: Turning spoken words into text. For a ring, the hard part is hearing a voice from a moving hand. Can a ring understand a mumble?
Text-to-speech: Software that reads text aloud in a synthetic voice. How AI voices work.
Verification of payee: A free check, required in the euro area since October 2025, that compares the account number of a transfer with the payee’s name before you send it. Instant transfers in Europe.
Vision-language-action model: An AI model that takes in images and instructions and puts out a robot’s actions, trained on robot data as well as on text and images from the web. When AI leaves the screen.
Wake word: A phrase a voice assistant listens for all the time before it starts recording. How to switch one off: turn off “Hey Siri” and “Hey Google”.
Wellness insight: A health-related observation, such as a sleep trend, that is not a medical measurement and not for diagnosis. What a wellness wearable may tell you.
Wero: A European payment wallet from banks’ European Payments Initiative, built on instant transfers: money to a phone number, online shopping, and payments in shops starting. More.
Word error rate (WER): The usual score for speech recognition: roughly, how many words come out wrong, missing or added per hundred words of a careful human transcript. What it shows in noise.