Abstract: The disclosed ultrasound devices may include at least one ultrasound transmitter positioned and configured to transmit ultrasound signals toward a user's face to reflect off a facial feature of the user's face and at least one ultrasound receiver positioned and configured to receive and detect the ultrasound signals reflected off the facial feature. At least one processor may be configured to receive data from the at least one ultrasound receiver and to determine, based on the received data from the at least one ultrasound receiver, at least one of the following eye measurements: an interpupillary distance of the user; an eye relief; or a position of a head-mounted display relative to the facial feature of the user. Various other devices, systems, and methods are also disclosed.

Abstract: According to examples, systems, devices, and methods for detecting rapid eye movement (REM) are described. The device may include an array of ultrasound sensors oriented to emit transmit ultrasounds signals in an eyeward direction, wherein the ultrasound sensors are to receive a return signal of the transmit signal reflecting off of a target, and wherein the ultrasound sensors are to output a distance signal representative of a distance to a target, the distance signal generated based on the return signal, and a transceiver to receive the distance signals, wherein the transceiver is to transmit the distance signals from the array of ultrasound sensors to a remote device.