In wards, the respiratory rate of bedridden patients can significantly reflect their pathological status. Wi-Fi signals, with their secure, ubiquitous, and low-cost characteristics, have become an effective means for respiratory monitoring. This work introduces a method for respiration detection using Wi-Fi CSI (channel state information), characterized by the ability to use deployed Wi-Fi devices as signal sources. We have introduced an innovative approach that effectively suppresses interfering noise, thereby achieving results with high accuracy. Simulations indicate that our proposed method can achieve an error of less than 0.5 breaths per minute in real hospital ward scenarios.