#IWATCH RECORD LECTURES SERIES#

In addition, the optical heart sensor is designed to compensate for low signal levels by increasing both LED brightness and sampling rate. The optical heart sensor supports a range of 30–210 beats per minute. By flashing its LED lights hundreds of times per second, Apple Watch can calculate the number of times the heart beats each minute - your heart rate. When your heart beats, the blood flow in your wrist - and the green light absorption - is greater.

Apple Watch uses green LED lights paired with light‑sensitive photodiodes to detect the amount of blood flowing through your wrist at any given moment. This technology, while difficult to pronounce, is based on a very simple fact: Blood is red because it reflects red light and absorbs green light. The optical heart sensor in Apple Watch uses what is known as photoplethysmography.

Some anomalies may appear in the displayed data, resulting in occasional heart rate measurements that are abnormally high or low. You can control which third-party apps have access to your health data from the Health app in Sources. Apple Watch also calculates a daily resting rate and walking average by correlating background heart rate readings with accelerometer data when sufficient background readings are available. Since Apple Watch takes these background readings based on your activity, the time between these measurements will vary.

#IWATCH RECORD LECTURES SERIES#

In addition, Apple Watch measures your heart rate throughout the day when you’re still, and periodically when you’re walking (Apple Watch Series 1 or later). This information, as well as other data it collects, helps Apple Watch estimate how many calories you’ve burned. If you don't see your heart rate, check your settings. When you use the Workout app, Apple Watch measures your heart rate continuously during the workout and for 3 minutes after the workout ends to determine a workout recovery rate.

Iwatch record lectures