# SensorKit updates Learn about important changes to SensorKit. ## Overview Browse notable changes in . ## March 2024 ### Sensors - Use the property to collect electrocardiogram (ECG) data samples, and the class to get the data. - Use the property to collect photoplethysmogram (PPG) data samples, and the and classes to get the data. ## June 2023 ### Sensors - Use the property to analyze a person’s facial expressions, and the class to get the data. - Use the property to collect a person’s heart rate from devices, and the class to get the data. - Use the property to analyze movements during workouts, and the class to get the data. - Use the property to collect data about a person’s voice — such as tenor, pitch, and cadence — and the class to get the data. People who previously authorized speech metric data collection need to reauthorize before data collection can continue. - Use the property to collect sequential wrist temperatures while a person is sleeping, and the class to get the data. ### Configuration - To opt out of collecting data for user activity from sensors in your app, set the key to `NO`. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)