就是(shi)當患者的(de)(de)呼(hu)吸(xi)(xi)周期(qi)(qi)小于后(hou)備(bei)通(tong)氣頻(pin)率(lv)對應的(de)(de)周期(qi)(qi)時(shi),機器(qi)工作(zuo)在(zai)S模(mo)式(shi)(shi)(shi)(shi);當患者的(de)(de)呼(hu)吸(xi)(xi)周期(qi)(qi)大于后(hou)備(bei)通(tong)氣頻(pin)率(lv)時(shi),機器(qi)工作(zuo)在(zai) T 模(mo)式(shi)(shi)(shi)(shi)。如(ru)(舉例):BPM=10次/分,呼(hu)吸(xi)(xi)周期(qi)(qi)=60秒/10=6秒,則(ze)呼(hu)吸(xi)(xi)機等待6秒,如(ru)病(bing)人能在(zai)6秒內(nei)觸發(fa)呼(hu)吸(xi)(xi)機,呼(hu)吸(xi)(xi)機則(ze)為S工作(zuo)模(mo)式(shi)(shi)(shi)(shi),相反(fan)則(ze)為T模(mo)式(shi)(shi)(shi)(shi)。此模(mo)式(shi)(shi)(shi)(shi)使用(yong)普遍,用(yong)于與呼(hu)吸(xi)(xi)有關的(de)(de)各種(zhong)病(bing)人。