Department of Mechanical Engineering, Centre for Bio-Engineering, University of Canterbury, Christchurch, New Zealand.
Department of Mechanical Engineering, Centre for Bio-Engineering, University of Canterbury, Christchurch, New Zealand; University of Liége, Liége, Belgium.
Comput Methods Programs Biomed. 2024 Feb;244:107988. doi: 10.1016/j.cmpb.2023.107988. Epub 2023 Dec 19.
Recruitment maneuvers with subsequent positive-end-expiratory-pressure (PEEP) have proven effective in recruiting lung volume and preventing alveoli collapse. However, determining a safe, effective, and patient-specific PEEP is not standardized, and this more optimal PEEP level evolves with patient condition, requiring personalised monitoring and care approaches to maintain optimal ventilation settings.
This research examines 3 physiologically relevant basis function sets (exponential, parabolic, cumulative) to enable better prediction of elastance evolution for a virtual patient or digital twin model of MV lung mechanics, including novel elements to model and predict distension elastance. Prediction accuracy and robustness are validated against recruitment maneuver data from 18 volume-controlled ventilation (VCV) patients at 7 different baseline PEEP levels (0 to 12 cmHO) and 14 pressure-controlled ventilation (PCV) patients at 4 different baseline PEEP levels (6 to 12 cmHO), yielding 623 and 294 prediction cases, respectively. Predictions were made up to 12 cmHO of added PEEP ahead, covering 6 × 2 cmHO PEEP steps.
The 3 basis function sets yield median absolute peak inspiratory pressure (PIP) prediction error of 1.63 cmHO for VCV patients, and median peak inspiratory volume (PIV) prediction error of 0.028 L for PCV patients. The exponential basis function set yields a better trade-off of overall performance across VCV and PCV prediction than parabolic and cumulative basis function sets from other studies. Comparing predicted and clinically measured distension prediction in VCV demonstrated consistent, robust high accuracy with R = 0.90-0.95.
The results demonstrate recruitment mechanics are best captured by an exponential basis function across different mechanical ventilation modes, matching physiological expectations, and accurately capture, for the first time, distension mechanics to within 5-10 % accuracy. Enabling the risk of lung injury to be predicted before changing ventilator settings. The overall outcomes significantly extend and more fully validate this digital twin or virtual mechanical ventilation patient model.
采用复张手法并给予呼气末正压(PEEP)已被证实可有效增加肺容积、防止肺泡萎陷。然而,确定一个安全、有效的、个体化的 PEEP 尚未标准化,而且这个更理想的 PEEP 水平会随着患者病情的变化而变化,需要采用个性化的监测和护理方法来维持最佳的通气设置。
本研究使用了 3 种生理相关的基函数集(指数、抛物线、累积),以更好地预测 MV 肺力学的虚拟患者或数字双胞胎模型的顺应性演变,包括用于模拟和预测扩张顺应性的新元素。通过对 18 例容量控制通气(VCV)患者在 7 个不同基础 PEEP 水平(0 至 12cmH2O)和 14 例压力控制通气(PCV)患者在 4 个不同基础 PEEP 水平(6 至 12cmH2O)进行复张手法的数据进行验证,分别得到了 623 个和 294 个预测病例,预测结果分别覆盖了 12cmH2O 的外加 PEEP 范围,涵盖了 6×2cmH2O 的 PEEP 步骤。
3 种基函数集在 VCV 患者中预测最大吸气压力(PIP)的中位数绝对峰值的误差为 1.63cmH2O,在 PCV 患者中预测最大吸气量(PIV)的中位数误差为 0.028L。指数基函数集在 VCV 和 PCV 预测方面的整体性能表现优于其他研究中使用的抛物线和累积基函数集。在 VCV 中,将预测的和临床测量的扩张预测进行比较,结果显示一致性和稳健性很高,相关系数 R 为 0.90-0.95。
研究结果表明,在不同的机械通气模式下,复张力学最好用指数基函数来捕捉,这符合生理预期,并首次准确地捕捉到扩张力学,误差在 5-10%以内。能够在改变呼吸机设置之前预测肺损伤的风险。整体结果显著扩展并更充分地验证了这个数字双胞胎或虚拟机械通气患者模型。