Abstract: Systems and methods for authenticating a passive speaker include (i) activating, by a playback device configured to drive the passive speaker, a passive speaker identification circuit of the passive speaker by providing an identification signal to an input terminal of the passive speaker, wherein the passive speaker is a particular type of passive speaker having particular acoustic characteristics; (ii) while the passive speaker identification circuit is active, measuring, by the playback device, an electrical current of the identification signal; (iii) determining, based on the measured electrical current of the identification signal, an impedance modulation of the passive speaker; (iv) determining, by the playback device, the particular type of the passive speaker based on the impedance modulation of the passive speaker; and (v) applying, by the playback device, a calibration to the playback device based on the determined particular type of the passive speaker.

Abstract: An assembly for lifting a lower eyelid can be surgically implanted into a patient. The assembly can include a mounting plate, an eyelid support member, and an elongate shaft that extends between and couples the mounting plate to the eyelid support member. The mounting plate can be coupled to facial bone, such as the zygomatic bone, while the eyelid support member contacts and lifts up an inferior tarsus and the lower eyelid of the patient.

Abstract: An assembly for lifting a lower eyelid can be surgically implanted into a patient. The assembly can include a mounting plate, an eyelid support member, and an elongate shaft that extends between and couples the mounting plate to the eyelid support member. The mounting plate can be coupled to facial bone, such as the zygomatic bone, while the eyelid support member contacts and lifts up an inferior tarsus and the lower eyelid of the patient.