Nguyen T-U, Diong B, Goldman M
Department of Engineering, Texas Christian University, Fort Worth, TX 76129, USA.
Annu Int Conf IEEE Eng Med Biol Soc. 2009;2009:2875-8. doi: 10.1109/IEMBS.2009.5333108.
Development of better methods to assess human lung function has been continuing since the existing standard lung function test of spirometry requires subjects to inhale and exhale with maximum effort, which may be troublesome especially for the elderly and young children, leading to unreliable results. Therefore, the method of forced oscillation, and the Impulse Oscillometry System (IOS) in particular, has been developed to lessen the effort of the patients while obtaining valid measurements. The applied pressure waves and the resulting airflow responses are recorded to provide information about the respiratory system's input impedance, which can be fit by electric circuit models to possibly serve as a means to detect and diagnose respiratory diseases. Presently, research continues to find a more accurate model that also provides reasonable component values. This paper proposes the augmented RIC+I(p)(aRIC+I(p)) model and compares it to five other well-known models (the RIC, extended RIC, augmented RIC, DuBois and Mead models) in fitting the IOS data from adult COPD patients and healthy subjects. While the aRIC+I(p) model yielded slightly higher fitting error than the Mead and DuBois models, it did not produce unphysiologically large values for any of its components, unlike the Mead and DuBois models. Hence, the aRIC+(p) model appears to be the most reasonable one for use, at this point in time, in studying IOS-based computer-aided detection and diagnosis of COPD.
由于现有的标准肺功能测试——肺活量测定法要求受试者最大程度地吸气和呼气，这对老年人和幼儿来说可能很麻烦，导致结果不可靠，因此，一直在持续开发更好的评估人体肺功能的方法。因此，已经开发出强迫振荡法，尤其是脉冲振荡法系统（IOS），以减少患者的用力程度，同时获得有效的测量结果。记录施加的压力波和由此产生的气流响应，以提供有关呼吸系统输入阻抗的信息，该信息可以用电路模型拟合，可能用作检测和诊断呼吸系统疾病的一种手段。目前，研究仍在继续寻找一种更准确的模型，该模型还能提供合理的组件值。本文提出了增强的RIC+I(p)（aRIC+I(p)）模型，并将其与其他五个著名模型（RIC、扩展RIC、增强RIC、杜波依斯模型和米德模型）在拟合成年慢性阻塞性肺疾病（COPD）患者和健康受试者的IOS数据方面进行了比较。虽然aRIC+I(p)模型产生的拟合误差略高于米德模型和杜波依斯模型，但与米德模型和杜波依斯模型不同的是，它的任何组件都没有产生不符合生理的大值。因此，在目前这个时间点上，aRIC+(p)模型似乎是用于基于IOS的COPD计算机辅助检测和诊断研究中最合理的模型。
