Today the US Patent & Trademark Office published a patent application from Apple that relates to a next-generation of AirPods Sensor System wherein the housing and tips of AirPods could include a number of active and reference electrodes configured to measure biosignals and electrical activity of a user’s brain. The biosignals measured by AirPods could include, but are not limited to, an electroencephalography (EEG), electromyography (EMG), electrooculography (EOG) and more.
In Apple’s patent background they note that brain activity can be monitored using electrodes placed on the scalp of a user. The electrodes may in some cases be placed inside or around the outer ear of the user. Measuring of the brain activity using electrodes placed in or around the outer ear may be preferred due to benefits such as reduced device mobility and decreased visibility of the electrodes when compared to other devices that require electrodes to be placed on visible areas around the scalp of the user.
However, for accurate measurements of brain activity using an ear-electroencephalography (EEG) device, the ear-EEG device may need to be customized for a user’s ear (e.g., possibly customized for the user’s concha, ear canal, targus, etc.), and may need to be customized differently for different users, so that the electrodes placed on the ear-EEG device may remain in continuous contact with a user’s body.
Because an ear’s size and shape vary from one user to another, and because a single user’s ear size and shape, and size and shape of structures such as a user’s ear canal, may change over time, even a customized ear-EEG device may fail to generate accurate measurements at times (or over time). In addition, a customized ear-EEG device may be expensive.
Biosignal Sensing Device Using Dynamic Selection Of Electrodes
Apple’s granted patent covers an invention that generally relates to a wearable electronic device (AirPods) for measuring biosignals of a user. The device may have more electrodes than are necessary to measure the biosignals for a given user, and the device may dynamically select a subset of the electrodes for measuring the biosignals for a given user at a given time.
The wearable electronic device, as described herein, may include a housing and a number of active and reference electrodes on the housing. The number of active and reference electrodes may be configured to measure biosignals of a user of the wearable electronic device.
The biosignals measured by the wearable electronic device may include, but are not limited to, an electroencephalography (EEG). In some embodiments, other biosignals may be measured, such as an electromyography (EMG), electrooculography (EOG), an electrocardiogram (ECG), a galvanic skin response (GSR), a blood volume pulse (BVP), etc.
The device may dynamically select different subsets of the electrodes for measuring the biosignals for different users or at different times (e.g., depending on parameters of the user, how the device is being worn, ambient affects, etc.). In some cases, the embodiments/aspects described herein pertain to an earbud (AirPods) and/or a headset. A headset, as described in the patent is simply wired EarPods.
In one aspect, a wearable electronic device is described. The wearable electronic device may include a housing and an electronic carrier attached to the housing having a nonplanar surface. The wearable electronic device may include a set of electrodes including electrodes positioned at different locations on the nonplanar surface, a sensor circuit, and a switching circuit. The switching circuit is operable to electrically connect a number of different subsets of one or more electrodes in the set of electrodes to the sensor circuit.
In a second aspect, a wearable electronic device is described. The wearable electronic device may include a housing, a set of active electrodes, and a set of reference electrodes. The sets of active and reference electrodes are disposed in different positions or regions of the housing. The wearable electronic device includes a switching circuit configured to form one or more subsets of active electrodes each including at least one active electrode of the set of active electrodes, and one or more subsets of reference electrodes each including at least one reference electrode of the set of reference electrodes.
In a third aspect, an apparatus configured to measure a biosignal is described. The apparatus may include a first component configured to be worn on or in a first ear, and a second component configured to be worn on or in a second ear. The first component may include a set of active electrodes disposed in different regions of a housing of the first component, and the second component may include a set of reference electrodes disposed in different regions of a housing of the second component.
Apple’s patent FIG. 2 below illustrates a possible next-gen AirPods with a series of ‘Active Electrodes’ placed on surface of the replaceable tips. Alternatively, Apple notes that the active electrodes could also be embedded in the material of the tip. In addition, a single tap in the area where the reference electrode 210a is shown may be interpreted as a command to start a measurement of a biosignal, for example, an electroencephalogram (EEG) for measuring brain activity.
Apple’s patent FIGS. 3 and 4 above illustrate different patterns of active electrodes on an AirPods tip.
Apple’s patent FIG. 5 above depicts a user tapping on AirPods to turn on or off a feature to measure a biosignal. In some embodiments, an optical sensor in the earbud may also be configured to receive an input from the user to start and/or stop measurement of the biosignal.
Apple also notes that in some embodiments, the wearable electronic device may alternatively be a pair of smartglasses, and active and reference electrodes may be placed in temple areas of the pair of glasses. For example, active and reference electrodes may be respectively positioned on a first stem and a second stem of the pair of glasses.
Apple’s patent FIGS. 11A-11B below depict example views of biosignals measured by electrodes.
(Click on image below to Enlarge)
For more details, review Apple’s patent application number 20230225659.
A Patently Apple fan by the name of Hassan wondered if this could be a part of a larger project such as a Brain Computer Interface (BCI)? That’s an interesting observation and only time will tell if the project leans that way over time.
Team Members on this Apple Project
- Vicki Powell: Health Tech Hardware Engineer
- Steve Hotelling: Senior Manager, Touch Hardware
- Erdrin Azemi: Senior Engineering Manager, AI/ML Research
- Anuranjini Pragada: Engineering Manager, Mechanical Product Design
- Jean Lu: Engineering Manager (Imaging & Sensing Incubation)
- Juri Minxha: AI/ML
- Ali Moin: AI Research
