Apple has made their Apple Watch a health tool amongst other things by adding several sensors over time. Today the U.S. Patent and Trademark Office officially published a patent application from Apple that reveals systems and methods for monitoring respiratory parameters of a user and more particularly to systems and methods for determining respiratory rates for a user using impedance-based measurements.

Respiratory Measurement System

Embodiments in Apple's patent filing are directed to an Apple Watch (wearable device) that includes watch band configured to secure the wearable device to a wrist of a user and a plurality of electrodes positioned to contact the user when the band secures the wearable device to the wrist of the user.

A future version of Apple Watch could include a processor that is configured to cause the plurality of electrodes to apply electrical signals to the user, measure the electrical signals from the user using the plurality of electrodes, generate a set of impedance data from the measured electrical signals, and identify one or more respiratory cycles using the set of impedance data.

Embodiments are also directed to an Apple Watch that includes electrodes configured to apply one or more electrical signals to a user and sense the one or more electrical signals from the user. The wearable device could include a processor configured to perform one or more first impedance measurements using the electrodes to determine a set of contact metrics, select a subset of the electrodes using the set of contact metrics, perform one or more second impedance measurements using the subset of the electrodes to generate a set of impedance data, and determine one or more respiratory cycles of the user from the set of impedance data.

Embodiments are further directed to a wearable sensing device for measuring a respiratory parameter of a user and including a set of electrodes configured to apply an electrical signal to a body of the user and sense the electrical signal from the body and a motion sensor configured to measure motion of the user. The wearable sensing device can include a processor that is configured to determine that a motion state of the user meets a low motion criteria using the measured motion. In response to determining that the motion state meets the low motion criteria, the processor can use the set of electrodes to measure impedance of the user while the set of electrodes contacts the user and determines the respiratory parameter of the user from the measured impedance.

Apple's patent FIG. 1 below illustrates a functional block diagram of an example electronic device that may be used to perform impedance-based respiratory measurements; FIG. 2A shows an example watch that may incorporate a sensing system as described herein; FIG. 2B shows a rear view of the example watch of FIG. 2A, which includes a sensing system positioned on the housing of the watch.

Apple's patent FIG. 3 above shows an example process for performing impedance respiratory measurements using an electronic device; FIG. 4 shows a visual example of impedance data generated by the sensing systems.

The devices, which could be an Apple Watch, bracelet, cuff, ring, band, a future HMD or the like and could include one or more electrodes that are positioned to contact a user and are used to perform impedance measurements at a body part of a user.

The devices could generate impedance data from the measurements and process the impedance data to determine physiological parameters including respiratory parameters, cardiac parameters, or other parameters of the user.

In some cases, the impedance measurements may detect changes in blood flow through the body part of a user (e.g., as a result of the cardiac cycle) and the impedance data may be analyzed to identify shifts in the blood flow induced by the user's respiration.

For example, the impedance measurements may capture pulsatile fluctuations of the blood flow and respiratory induced changes to the pulsatile blood flow. Analyzing the impedance data can include identifying the pulsatile characteristics of the blood flow and identifying respiratory induced shifts in the pulsatile signal. The devices and systems may derive one or more respiratory parameters, including a breathing rate, and display or otherwise output the parameter(s) to the user.

To review the full details of this invention, check out patent application 20240188845.