Ren Shuai, Niu Jinglong, Cai Maolin, Hao Liming, Shi Yan, Xu Weiqing, Luo Zujin
School of Automation Science and Electrical Engineering, Beihang University, Beijing, 100191 China.
State Key Laboratory of Fluid Power and Mechatronic Systems, Zhejiang University, Hangzhou, 310027 China.
Biodes Manuf. 2021;4(3):479-489. doi: 10.1007/s42242-021-00132-9. Epub 2021 Apr 19.
Cough is a defensive behavior that protects the respiratory system from infection and clears airway secretions. Cough airflow dynamics have been analyzed by a variety of mathematical and experimental tools. In this paper, the cough airflow dynamics of 42 subjects were obtained and analyzed. An identification model based on piecewise Gauss function for cough airflow dynamics is proposed through the dimensionless method, which could achieve over 90% identification accuracy. Meanwhile, an assisted cough system based on pneumatic flow servo system is presented. The vacuum situation and feedback control are used to increase the simulated peak cough flow rate, which are important for airway secretion clearance and to avoid airway collapse, respectively. The simulated cough peak flow could reach 5 L/s without the external assistance such as manual pressing, patient cooperation and other means. Finally, the backstepping control is developed to generate a simulated cough airflow that closely mimics the natural cough airflow of humans. The assisted cough system opens up wide opportunities of practical application in airway secretion clearance for critically ill patients with COVID 2019 and other pulmonary diseases.
咳嗽是一种保护呼吸系统免受感染并清除气道分泌物的防御行为。咳嗽气流动力学已通过多种数学和实验工具进行分析。本文获取并分析了42名受试者的咳嗽气流动力学。通过无量纲方法提出了一种基于分段高斯函数的咳嗽气流动力学识别模型，其识别准确率可达90%以上。同时，提出了一种基于气动流量伺服系统的辅助咳嗽系统。利用真空情况和反馈控制分别提高模拟咳嗽峰值流速，这对于气道分泌物清除和避免气道塌陷很重要。在没有手动按压、患者配合等外部辅助手段的情况下，模拟咳嗽峰值流速可达5升/秒。最后，开发了反步控制以生成紧密模仿人类自然咳嗽气流的模拟咳嗽气流。该辅助咳嗽系统为2019冠状病毒病及其他肺部疾病的重症患者在气道分泌物清除方面开辟了广阔的实际应用前景。
