Solav Dana, Meric Henri, Rubin M B, Pradon Didier, Lofaso Frédéric, Wolf Alon
Faculty of Mechanical Engineering, Technion Israel Institute of Technology, 32000, Haifa, Israel.
Center for Extreme Bionics, MIT Media Lab, Massachusetts Institute of Technology, Cambridge, MA, 02139, USA.
Ann Biomed Eng. 2017 Aug;45(8):1963-1973. doi: 10.1007/s10439-017-1840-6. Epub 2017 Apr 27.
Optoelectronic plethysmography (OEP) is a noninvasive method for assessing lung volume variations and the contributions of different anatomical compartments of the chest wall (CW) through measurements of the motion of markers attached to the CW surface. The present study proposes a new method for analyzing the local CW kinematics from OEP measurements based on the kinematics of triangular Cosserat point elements (TCPEs). 52 reflective markers were placed on the anterior CW to create a mesh of 78 triangles according to an anatomical model. Each triangle was characterized by a TCPE and its kinematics was described using four time-variant scalar TCPE parameters. The total CW volume ([Formula: see text]) and the contributions of its six compartments were also estimated, using the same markers. The method was evaluated using measurements of ten healthy subjects, nine patients with Pompe disease, and ten patients with Duchenne muscular dystrophy (DMD), during spontaneous breathing (SB) and vital capacity maneuvers (VC) in the supine position. TCPE parameters and compartmental volumes were compared with [Formula: see text] by computing the phase angles [Formula: see text] (for SB) and the correlation r (for VC) between them. Analysis of [Formula: see text] and r of the outward translation parameter [Formula: see text] of each TCPE revealed that for healthy subjects it provided similar results to those obtained by compartmental volumes, whereas for the neuromuscular patients the TCPE method was capable of detecting local asynchronous and paradoxical movements also in cases where they were undistinguished by volumes. Therefore, the TCPE approach provides additional information to OEP that may enhance its clinical evaluation capabilities.
光电体积描记法（OEP）是一种非侵入性方法，通过测量附着在胸壁（CW）表面的标记物的运动来评估肺容积变化以及胸壁不同解剖区域的贡献。本研究提出了一种基于三角形柯塞尔点元素（TCPE）运动学从OEP测量中分析局部胸壁运动学的新方法。根据解剖模型，在胸壁前部放置了52个反射标记物，以创建一个由78个三角形组成的网格。每个三角形由一个TCPE表征，其运动学用四个随时间变化的标量TCPE参数来描述。还使用相同的标记物估计了胸壁总体积（[公式：见正文]）及其六个区域的贡献。该方法在仰卧位的自发呼吸（SB）和肺活量动作（VC）期间，对10名健康受试者、9名庞贝病患者和10名杜兴氏肌营养不良症（DMD）患者的测量结果进行了评估。通过计算它们之间的相位角[公式：见正文]（用于SB）和相关性r（用于VC），将TCPE参数和区域体积与[公式：见正文]进行了比较。对每个TCPE向外平移参数[公式：见正文]的[公式：见正文]和r的分析表明，对于健康受试者，它提供的结果与通过区域体积获得的结果相似，而对于神经肌肉疾病患者，TCPE方法能够检测到局部异步和矛盾运动，即使在体积无法区分的情况下也是如此。因此，TCPE方法为OEP提供了额外信息，可能会增强其临床评估能力。
