How the sensor reads your sleep: the science behind a home sleep test.

A modern home sleep test does not need a tangle of wires or a night in an unfamiliar lab. A single small sensor, worn at the base of the neck, can capture enough physiology to identify sleep apnoea with clinical-grade accuracy.

Airflow and vibration

A tiny microphone and motion sensor sit against the skin over the airway. As air moves in and out through the night, they pick up the sound of breathing and the subtle vibration of the tissues around the upper airway. When the airway narrows or briefly closes — as it does in obstructive sleep apnoea — the acoustic and vibration signature changes in a way the sensor can detect.

Breathing rhythm and oxygen

The same signal is used to track your breathing rate and rhythm across the night. When breathing becomes shallow or pauses, oxygen levels in the blood typically fall for a short period before recovering. These desaturations are a hallmark of sleep-disordered breathing and are counted alongside the apnoea and hypopnoea events themselves.

Heart rate and body position

Every apnoea or hypopnoea event puts a small amount of stress on the cardiovascular system, and heart rate patterns often shift in response. The sensor also tracks the position you are sleeping in — some people only have significant sleep apnoea when they lie on their back, which is useful information for treatment.

Clinical analysis

In the morning, the recording is transmitted securely. Software processes the raw signal into an event-by-event timeline: apnoeas, hypopnoeas, desaturations, heart-rate response and position. A clinician then reads the full trace themselves — not just the summary numbers — before signing off your result.

Why this matters

The number of breathing events per hour of sleep (the apnoea-hypopnoea index, or AHI) is what determines whether you have sleep apnoea and how severe it is. Combined with your symptoms and health background, the trace guides a personal recommendation on next steps — from simple positional and lifestyle changes to referral for treatment such as CPAP.

Because the device is small, reusable and returned by post, a home sleep test is quicker, more comfortable and considerably lower-waste than a traditional overnight lab study — while still giving you and your clinician the clinical picture you need.