RESUMEN
BACKGROUND: Mortality related to cardiopulmonary bypass can be lowered by intra-operative monitoring system.Monitoring liquid level and pressure is extremely indispensable for examination of cardiopulmonary bypass(CPB).OBJECTIVE: To design a CPB safety system including an arterial line pressure monitor and low-level sensor,and to evaluate its safety and effects in clinical settings.METHODS: The safety system was composed of pressure transducer,photoelectric transmitter,photoelectric detector,core controller,and liquid crystal display.The principles of reflection and refraction were applied to the design of level sensor.The pressure measurements were converted into electronic signals and processed.According to two principles above-mentioned,fluid level detector and pressure monitor were designed.Thirty patients with the age of 1-75 years receiving cardiac surgery with cardiopulmonary bypass were enrolled.The arterial line pressure at different pump flows was measured and the alarm function of the level sensor was also validated.RESULTS AND CONCLUSION: Cardiopulmonary bypass arterial line pressure increased with the pump flow.Arterial line pressure detected by HZ-01-A safety system also increased with the pump flow increasing,which was highly related to the pump pressure.HZ-01-A safety system could alarm when the arterial line pressure and reservoir level exceeded the pre-determined thresholds.HZ-01-A safety system could be safely and effectively applied to clinical cardiopulmonary bypass and improve bypass safety by accurately detecting the pressure and reservoir level.