A mouse device includes a grip part, an extension part, an infrared light sensing unit, and a controlling unit. The extension part is extended from the grip part for supporting a wrist of a user. The infrared light sensing unit includes an infrared light source and an image sensor. The infrared light source emits an infrared light beam. A portion of the infrared light beam within a specified wavelength range is absorbed by the plural blood vessels of the wrist. Another portion of the infrared light beam beyond the specified wavelength range is reflected from the plural blood vessels to the image sensor, so that plural infrared images are generated. The controlling unit calculates a blood flow rate of the plural blood vessels of the wrist according to the plural infrared images, and acquires the body information of the user according to the blood flow rate.
