Apple invents a Miniature External Temperature Sensing Device for Wearables that estimates subsurface tissue temperatures
Today the US Patent & Trademark Office published a patent application from Apple that relates to Apple including a temperature sensing device in wearable devices such as an Apple Watch, AirPods, future smartglasses and VR Headset that is configured to estimate subsurface tissue temperatures, heart rate, a barometric pressure, air temperature, moisture level, and so on.
Apple's patent covers miniature temperature sensing devices for use in, or incorporation into, portable and/or wearable electronic devices. The temperature sensing device can be used to estimate a subsurface tissue temperature of a user by measuring temperatures at the skin of the user.
It may be desirable to estimate subsurface tissue temperatures of a user as these temperatures may be more stable over time and/or accurate in determining a current condition of a user such as whether they have an elevated or depressed temperature.
In some embodiments, the temperature sensing device can have a sensor body that has two sections of different thicknesses and two or more sets of temperature sensors configured to measure temperature differentials across the different sections. Such temperature sensing devices may be referred to as "dual heat flux temperature sensors."
Dual heat flux temperature sensors may be placed such that the sensor body is on a surface, such as a skin of a user; the temperature sensor may estimate a subsurface temperature (e.g., a deep tissue temperature of a user) by measuring temperature differences across the two different thicknesses of the sensor body.
For example, the sensor body can have an inner cylindrical section that is thicker or taller than an outer toroidal section that extends around a circumference of the inner section, such that the sensor body defines a top hat-like structure. A first set of temperatures sensors can be positioned to measure temperature differences across the thicker, inner cylindrical section and a second set of temperature sensors can be positioned to measure temperature differences across the thinner, outer toroidal section.
The temperature differentials across each of these sections can be used to estimate the subsurface tissue temperature of a user. In some cases, additional sets of temperature sensors may be placed at different locations along the first and/or second sections, which may help increase the accuracy of the temperature measurements across each of the sections.
Apple's patent FIG. 1 below shows an Apple Watch that includes a temperature sensing device; FIGS. 2A and 2B illustrate an enlargement of a temperature sensing device that can be included in an Apple Watch.
The electronic device (Apple Watch #100) may be worn by a user and include one more sensors that determine a condition(s) of the user such as a body temperature, heart rate, position, direction of movement, and so on, and/or a condition of the environment such as a barometric pressure, air temperature, moisture level, and so on. Different sensors may be positioned at different locations on or within the electronic device depending on operating requirements of a particular sensor, the condition being detected by the sensor, the design of the electronic device, and so on.
While Apple's patent FIG. 1 illustrates the temperature sensor being apart from the digital crown, in another example, Apple describes this temperature device possibly being apart of a next-gen digital crown with new capabilities. Apple notes:
"In some cases, the device [Apple Watch #100] may sense touch inputs or gestures applied to the crown [#108], such as a finger sliding along the body of the crown (which may occur when the crown is configured to not rotate) or a finger touching the body of the crown.
In such cases, sliding gestures may cause operations similar to the rotational inputs, and touches on an end face may cause operations similar to the translational inputs."
Allowing the use of touch gestures over the crown area was covered in a granted patent report posted yesterday titled "Apple wins a Patent for Replacing the Apple Watch Digital Crown with an Optical Sensor that recognizes user Gestures & more."
For more details, review Apple's patent application number 20210404883. Considering that this is a patent application, the timing of such a product to market is unknown at this time.