In open heart surgery,perioperative arterial pressure is an important index for Circulatory monitoring.Pressure sensor,an invasive arterial pressure monitor,can provide accurate,reliable and continuous arterial pressure value,and determine the status of the blood volume or the heart through wave analysis.It is necessary to grasp the components,principle and technical requirements of biosensor applied to clinical practice.

Objective To evaluate the efficacy of pressure bladder indicator in guiding epidural puncture.Methods Test Ⅰ Thirty-two patients scheduled for epidural puncture were studied. After successful epidural puncture, the end of the epidural needle was connected to a pressure sensor to measure the epidural space pressure. Test Ⅱ Seventy patients scheduled for epidural puncture were studied. The epidural puncture was performed using the pressure bladder indicator. The successful condition of the pressure bladder indicator in guiding epidural puncture was recorded. Results The epidural space pressure was ( 10 ± 4) cm H2O. Seventy patients completed epidural pucture under the guidance of the pressure bladder indicator. The success rate was 100%.Conclusion The pressure bladder indicator can serve as an assistance for epidural puncture and has clinical application value.