pulse envelope

例句：

1. 1. The heart's rate is determined by the size of the pulse envelope.
   心率取决于脉搏包络的大小。
2. 2. The doctor used a special device to measure the pulse envelope during the test.
   医生使用一种特殊的设备来测量测试期间的脉搏包络。
3. 3. The study found that the pulse envelope can be used as an indicator of heart health.
   研究发现，脉搏包络可以作为心脏健康的指标。