Abstract: A child safety seat includes a seat base assembly, a sled assembly coupled to the seat base assembly, and a seat body assembly slidably coupled to the sled assembly. The sled assembly includes a modular energy absorber that is configured to reduce impact forces on an occupant of the seat body.

Abstract: A manometer for measuring a differential pressure within a patient's disc includes a housing attachable to a device that is in fluid communication with the patient's disc, a pressure transducer within the housing for measuring a pressure in the patient's disc, a memory within the manometer for saving a pressure measured by the transducer, an input device on the housing for receiving input from a user to save an initial pressure measured by the transducer in the memory, and a display on the housing. The display provides an indication of an initial pressure in the patient's disc measured by the transducer before the user provides input via the input device and an indication of a differential pressure between a subsequent pressure and the initial pressure in the patient's disc after the user provides input via the input device. Related methods are also disclosed.