Apple's first 'temperature sensor' for Apple Watch related to tracking a Women's menstrual cycle.  Last week, the U.S. Patent and Trademark Office officially published a patent application from Apple that relates to another type of temperature sensor. Apple notes that "Core temperatures can be measured with medical thermometers with access to a person's mouth or ear cavity, but these methods are invasive and not compatible with typical wearable electronic devices such as electronic watches." Apple's invention provides a solution.

Apple Watch wit Core Temperature Sensing

Due to Apple Watch being in contact with the user's body during use, it can be advantageous to use such a device for non-invasive measurement of the user's core body temperature based on a measurement of the user's surface skin temperature where the device makes contact.

However, the temperature of the device and the environment in which it is used can change from moment to moment during use such that detecting the user's core temperature with a wearable device can be challenging. Apple's invention could overcome these challenges by measuring a temperature difference between two locations within the device, with one of the locations being close to the portion of the device contacting the user's skin, and calculating a heat flux correction factor based on heat flux from the skin through the device.

The heat flux correction factor can be used in one or more algorithms, as executed by a processor of the device, to determine a surface temperature of the skin. The surface temperature can then be used to extrapolate a user's core temperature. The temperature difference between two locations within the device can be measured using a thin film thermopile having a hot junction at a first location (e.g., a location near the user's skin) and a cold junction at a second location (e.g., on a logic board within the device).

This is a highly technical invention. To review its rich details and many other patent figures, read patent application 20240074665.

Apple Inventors listed on the Patent

• James Clements: Health Tech. Mechanical Engineer. On his LinkedIn profile he notes: "My group is expanding to San Diego.
• Wei Lin: Sr. Hardware Manager
• Habib Karaki: Health Technologies Electrical Engineering Manager
• Xiaofan Niu: Camera process Engineer.
• Paul Mansky: Principal Technologist
• Boyi Fu: Staff Hardware Engineer
• Yanfeng Chen: Engineer
• Jeffrey Buchholz: Hardware Engineer.
• Daniel J. Hiemstra: No LinkedIn Profile.