Passenger seat having side sleep support assembly

An aircraft passenger seat, configured to facilitate ergonomic alignment of a passenger while in a sleeping position, includes a seat bottom; and a seatback including a central opening corresponding to a shoulder region of a passenger, and a sleep support assembly mounted within the central opening, the sleep support assembly including an adjustable support member spanning a central portion of theseatback, wherein the adjustable support member is configured for at least one of translation and deformation. When the seat bottom is aligned with the seatback in a lie-flat seating position, a loadprovided by the shoulder region of the passenger, at least in a side-sleeping position, causes translation and/or deformation of the adjustable support member toward a floor of an aircraft cabin, thereby facilitating ergonomic alignment of the spine 种飞机乘客座椅，配置为促进乘客在处于睡姿时的人体工程学对齐，包括：座椅底部；和座椅靠背，该座椅靠背包括与乘客的肩部区域对应的中心开口，和安装在中心开口内的睡眠支撑组件，睡眠支撑组件包括跨越座椅靠背的中心部分的可调节支撑构件，其中，可调节支撑构件配置用于进行平移和变形中的至少种；其中，当座椅底部在平放就座状态中与座椅靠背对齐时，至少在侧睡状态中，由乘