The Study of Constant Pressure Ventilation with no spontaneous respiration
The ventilator which is the synthetical production of the modern science and medical technology is very useful at hospital. The ventilator is a type of clinical life support apparatus which can help patients to enhance lung ventilation and accelerate metabolization. How to control ventilation accurately and in time is one criterion to elevate the ventilator. With the development of the technology of computer, the ventilation control is progressing rapidly. Targeting a constant pressure is a useful ventilation way. But domestic ventilator cant improve the pressure overshoot that generated by the current flow and rightly adjust the raising time or the raising ratio of the pressure, ventilation cant meet changes of the patient. In this paper a first order adaptive model is proposed to control the ventilator providing constant pressure ventilation based on the RC mode of the lung and the RCC model of patient circuit and lung, when the patient has very weak or no spontaneous respiration. The raising time or the raising ratio of the pressure in the lung can be easily adjusted by the time const of this model. At the same time the pressure overshoot is weakened as far as possible, so the lung will be safe. Using least-squares method the airway resistance and compliance two of the most important lungs parameters can be estimated by the value of pressure and flow, these two parameters are calculated in time to make this model be adaptive to the lungs changes. Leaks which exist in the system composed by the ventilator and the patient are a hindrance to the ventilation. In this paper a model is inducted when there are leaks in the system and a way to detect, estimated and fill the leaks is demonstrated. The compensator of the first order model is reconstructed to provide the same constant pressure ventilation as there are no leaks. Above cited options are testified by simulation.
constant pressure ventilation compensator adaptive control leak
YI Weiwei ZHANG Qi WANG Yueke ZHU Zhaoxuan
Mechatronic and Automation School of National University of Defense Technology, Changsha, China,410073
国际会议
北京
英文
2007-08-05（万方平台首次上网日期，不代表论文的发表时间）