The US Food and Drug Administration (FDA) approved an implanted phrenic nerve-stimulator device as a new treatment for moderate-to-severe central sleep apnea (CSA). The remedē System (Respicardia) consists of a pacemaker-like battery pack that’s surgically implanted in the upper chest beneath the skin. Wires electrically stimulate the phrenic nerve as it travels from the neck to the diaphragm. The system delivers phrenic nerve impulses while also monitoring the patient’s respiratory signals during sleep, to integrate stimulated breaths with natural breathing.