苹果手表上市10年，卖出4000多万只

Core Insights - Apple launched a promotional video titled "Heartbeat of Li Classmate" on April 30, highlighting the heart rate detection and high heart rate notification features of the Apple Watch, allowing users to monitor their health in real-time [1] - Since the initial release of the Apple Watch in April 2015, Apple has sold over 40 million units annually, generating approximately $20 billion in revenue [1] - The Apple Watch faced skepticism at launch due to its high price point, with the basic model starting at $349 and the top model exceeding $10,000, leading to questions about its value compared to other fitness wearables [1] - The Apple Watch has evolved significantly from 2016 to 2018, introducing features like ECG monitoring, which has attracted a larger user base and opened up new market opportunities [1] Technical Functionality - Apple explained the heart rate monitoring functionality of the Apple Watch, which utilizes four sensors on the back: an infrared sensor, a light sensor, and two visible light LEDs, working together to measure heart rate [2] - The sensors detect changes in light absorption as blood flows through the wrist, allowing the device to calculate heart rate by measuring the amount of green light absorbed [2] - Apple has collected over 50,000 hours of data and recruited more than 400,000 users globally for heart health research, monitoring abnormal heart rate conditions [2]