The operation procedure of the cardiac monitor includes assessing the patient’s condition, connecting the power supply, checking the patient’s information, attaching electrode sheets, wearing oxygen saturation clips, tying cuffs, and adjusting values. 1. Evaluate the patient’s condition: check and evaluate the skin condition of the patient’s chest area, arm and fingers, and tell the patient and his/her family the purpose and process of the operation, as well as the precautions to be taken. 2. Connect the power supply: connect the power supply of the cardiac monitor and check the functions of the machine after it is turned on. 3. Check the patient’s information: check the patient’s information, assist the patient to expose the skin of the chest area, and clean it with alcohol cotton balls. 4. Attach the electrodes: Usually, RA is attached to the first intercostal space in the right midclavicular line of the patient; LA is attached to the left midclavicular line; RL is attached to the right midclavicular line at the level of the level of the level of the level of the level of the level of the level of the level of the level of the level of the level of the level of the left midclavicular line; and C is attached to the left edge of the sternum in the position of the fourth intercostal space. 5. Wear oxygen saturation clip: Clip the oxygen saturation clip on the patient’s finger, usually on the index finger, middle finger or ring finger. The patient’s finger is placed inside the oxygenation chamber with the surface of the nail facing upward. 6. Tie the cuff: Tie the cuff bag to the patient’s elbow socket at the two transverse fingers, palpable brachial artery pulsation, loosening and tightening can be 1 to 2 fingers as appropriate. 7. Adjust the value: according to the patient’s condition to adjust the mode of the instrument and so on. The above is the complete operation process of the cardiac monitor.