Today the US Patent & Trademark Office published a patent application from Apple that relates to their future over-head HMD and more specifically, about including advanced physiological sensors in the headset that could measure heart rate, temperature, brain activity and more.

Head-mounted displays are worn on heads of users and display graphical content. A typical head-mounted display includes a display, a head support, and a facial interface. The facial interface is typically made of or includes a compliant material (e.g., foam or rubber) that engages and conforms to the shape of the face. However, the facial interface may hide portions of the face from view of various physiological sensors and/or may influence physiological conditions that might otherwise provide valuable information. For example, the user may provide a facial expression that, absent facial contact with the facial interface, would take a certain form and would be observable, such as raising of brows for a surprised facial expression.

Apple's patent application covers a head-mounted display that includes a display unit and a facial interface that includes a physiological sensor for sensing a physiological condition of the user in the facial engagement region.

The facial interface may also be removably or interchangeably coupleable to the display. Thereby, facial interfaces of different sensing functionality and/or fit may be attached to the display, for example, according to different graphical content and/or different users. Furthermore, the facial interfaces may be removable for cleaning or replacement.

Apple's patent FIG. 5 below is a front view of the head-mounted display and the user depicting a facial engagement region on the user and a facial interface of the head-mounted display.

More importantly, patent FIG. 6 below is a schematic view of a facial interface with optional sensors that include monitoring heart rate, muscle activity, brain activity, temperature, and more.

Apple's patent FIG. 12B above is a rear view of a facial interface for evaluating a face of a user for identifying the suitable facial interface. The physiological sensors are shown as #132 surrounding the facial part of the HMD.

The force sensor, which Apple states could be hidden behind the facial interface. It's to provide accurate measurements of the force applied by the facial interface to ensure a comfortable fit on the user's face.

To measure moisture, the physiological sensor may be a moisture sensor such as a hygrometer or infrared moisture sensor. In the case of the moisture sensor being a hygrometer, the moisture sensor is in fluidic communication with the facial engagement region of the face.

To measure brain activity (e.g., electroencephalography or EEG), muscle activity (e.g., electromyography or EMG), and/or heart rate (e.g., electrocardiography or ECG), the physiological sensor may be a suitable bioelectric signal sensor.

In one example, the bioelectric signal sensor is an electrode that may take different forms depending on the physiological condition sensed (e.g., being physically different for sensing different bioelectric activity (e.g., bioelectric signals), such as brain activity, muscle activity, or heart activity).

The electrode may be incorporated into the covering, for example, having a conductive fiber that is woven into a woven fabric of the covering.

In another part of the patent, Apple notes that one of the sensors of the electronics of the display unit may sense conditions of one or more of the eyes of the user (e.g., locations of the eyes E, for example, using a camera and image recognition).

Apple's patent application that was published today by the U.S. Patent Office was filed back in Q1 2020 with some work having been done in Q1 2019. Considering that this is a patent application, the timing of such a product to market is unknown at this time.

All three Apple inventors were listed as Human Factor Design Engineers.