Frequently Asked Questions About Heart Rate Measurement - Withings ScanWatch Series Installation And Operating Instructions Manual

To view your continuous heart rate measurement graph, open the Health Mate
app and tap directly on the activity for which you activated the continuous mode.
Note: The continuous heart rate mode will be activated automatically after 2
minutes of running. It will stop automatically when the running session is over.

Frequently asked questions about heart rate measurement

What is the proactive heart scanning feature?
Since AFib symptoms are irregular or may not even be known to users,
ScanWatch offers a new early-warning detection capability. Through its
embedded PPG sensor, the device has the ability to continuously monitor heart
rate, which allows it to alert users to a potential issue even if they don't feel
palpitations. When ScanWatch detects an irregular heartbeat through its heart
rate sensor, it will prompt the user, via the watch display, to take an ECG reading.
When does ScanWatch measure your heart rate?
When you use the Workout Mode, ScanWatch measures your heart rate
continuously during the workout. In addition, ScanWatch measures your heart
rate throughout the day when you're motionless, and periodically when you're
walking. Since ScanWatch takes these background readings based on your
activity, the time between these measurements will vary.
How does ScanWatch measure your heart rate?
The optical heart sensor in ScanWatch uses what is known as
photoplethysmography (PPG). This technology is based on a very simple fact:
Blood is red because it reflects red light and absorbs green light. ScanWatch
uses green LED paired with light-sensitive photodiodes to detect the amount
of blood flowing through your wrist at any given moment. When your heart
beats, the blood flow in your wrist — and the green light absorption — is greater.
Between beats, it's less. By flashing its LED lights thousands of times per minute,
ScanWatch can calculate the number of times the heart beats each minute —
your heart rate. The optical heart sensor supports a range of 30–210 beats per
minute. In addition, the optical heart sensor is designed to compensate for low
signal levels by increasing both LED brightness and sampling rate.
ScanWatch uses green LED lights to measure your heart rate during workouts.
ScanWatch also measures your heart rate when manually recording an
electrocardiogram (ECG). It has built-in electrodes in the bezel (the upper ring)
and the back, which can measure the electrical signals across your heart when
used with the ECG recording. When you place your finger on the bezel, it creates
a closed circuit between your heart and both arms, capturing the electrical
impulses across your chest.
ScanWatch
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v1.0 | August, 2020