Middlesex University, London, United Kingdom.
Physiol Meas. 2018 Jul 6;39(7):074001. doi: 10.1088/1361-6579/aacc1c.
Newborns with lung immaturity often require continuous monitoring and treatment of their lung ventilation in intensive care units, especially if born preterm. Recent studies indicate that electrical impedance tomography (EIT) is feasible in newborn infants and children, and can quantitatively identify changes in regional lung aeration and ventilation following alterations to respiratory conditions. Information on the patient-specific shape of the torso and its role in minimizing the artefacts in the reconstructed images can improve the accuracy of the clinical parameters obtained from EIT. Currently, only idealized models or those segmented from CT scans are usually adopted.
This study presents and compares two methodologies that can detect the patient-specific torso shape by means of wearable devices based on (1) previously reported bend sensor technology, and (2) a novel approach based on the use of accelerometers.
The reconstruction of different phantoms, taking into account anatomical asymmetries and different sizes, are produced for comparison.
As a result, the accelerometers are more versatile than bend sensors, which cannot be used on bigger cross-sections. The computational study estimates the optimal number of accelerometers required in order to generate an image reconstruction comparable to the use of a CT scan as the forward model. Furthermore, since the patient position is crucial to monitoring lung ventilation, the orientation of the phantoms is automatically detected by the accelerometer-based method.
肺部不成熟的新生儿通常需要在重症监护病房中持续监测和治疗其肺部通气,尤其是早产儿。最近的研究表明,电阻抗断层成像(EIT)在新生儿和儿童中是可行的,并且可以定量识别呼吸条件改变后区域性肺充气和通气的变化。关于躯干的特定形状及其在最小化重建图像伪影方面的作用的信息可以提高从 EIT 获得的临床参数的准确性。目前,通常仅采用理想化模型或从 CT 扫描中分割的模型。
本研究提出并比较了两种方法,这两种方法可以通过基于(1)先前报道的弯曲传感器技术和(2)基于使用加速度计的新方法的可穿戴设备来检测特定于患者的躯干形状。
考虑到解剖学不对称和不同尺寸,对不同的体模进行了重建。
结果表明,加速度计比弯曲传感器更通用,因为弯曲传感器不能用于更大的横截面。计算研究估计了为了生成与使用 CT 扫描作为正向模型相当的图像重建所需的最佳加速度计数量。此外,由于患者的位置对监测肺通气至关重要,因此基于加速度计的方法会自动检测体模的方向。