Answer : 4. "स्फिग्मोमैनोमीटर"
Explanation :

In a basal blood pressure measuring method, an examinee presses a basal blood pressure measuring key after the examinee gets out of bed in the morning to start a sphygmomanometer to measure the basal blood pressure A microprocessor in the sphygmomanometer displays the measured basal blood pressure and date on a display .