pulse oximeter       
noun [ C ]  medical specialized uk/ˌpʌls ɒkˈsɪm.ɪ.tər/ us/ˌpʌls ɑːkˈsɪm.ə.t̬ɚ/ (also oximeter)
 脉搏血氧计
a device, usually attached to the end of a person's finger, used to measure the level of oxygen in their blood
  The nurse monitors the pulse oximeter and gets a reading of 85%. 护士查看了脉搏血氧计,得到一个85%的读数。 
 A pulse oximeter was put on his finger to check oxygen saturation into body tissue and pulse. 他的手指上放了一个脉搏血氧计,检测身体组织内的氧饱和程度和脉搏。 
 - More examples
 - A pulse oximeter was used to record the preoperative and postoperative pulse rates.
 - The patients were monitored using a pulse oximeter together with routine nursing observations.
 - A pulse oximeter probe was connected to one of the fingers on the side to be operated first.