Department of Biomedical Technology, Faculty of Biomedical Engineering, Czech Technical University in Prague, Nam. Sitna 3105, 272 01, Kladno, Czech Republic.
Department of Anaesthesiology, Perioperative and Intensive Care Medicine, Masaryk Hospital in Usti nad Labem, Faculty of Health Studies, J. E. Purkinje University in Usti nad Labem, Usti nad Labem, Czech Republic.
Sci Rep. 2022 Sep 6;12(1):15131. doi: 10.1038/s41598-022-19101-y.
The pressure reactivity index (PRx) is a parameter for the assessment of cerebrovascular autoregulation, but its calculation is affected by artifacts in the source biosignals-intracranial pressure (ICP) and arterial blood pressure. We sought to describe the most common short-duration artifacts and their effect on the PRx. A retrospective analysis of 935 h of multimodal monitoring data was conducted, and five types of artifacts, characterized by their shape, duration, and amplitude, were identified: rectangular, fast impulse, isoline drift, saw tooth, and constant ICP value. Subsequently, all types of artifacts were mathematically modeled and inserted into undisturbed segments of biosignals. Fast impulse, the most common artifact, did not alter the PRx index significantly when inserted into one or both signals. Artifacts present in one signal exceeded the threshold PRx in less than 5% of samples, except for isoline drift. Compared to that, the shortest rectangular artifact inserted into both signals changed PRx to a value above the set threshold in 55.4% of cases. Our analysis shows that the effect of individual artifacts on the PRx index is variable, depending on their occurrence in one or both signals, duration, and shape. This different effect suggests that potentially not all artifacts need to be removed.
压力反应指数（PRx）是评估脑血管自动调节的一个参数，但它的计算受到源生物信号（颅内压 [ICP] 和动脉血压）中的伪影的影响。我们旨在描述最常见的短持续时间伪影及其对 PRx 的影响。对 935 小时的多模式监测数据进行了回顾性分析，并确定了五种类型的伪影，其特征为形状、持续时间和幅度：矩形、快速脉冲、等线漂移、锯齿形和恒定的 ICP 值。随后，对所有类型的伪影进行了数学建模，并将其插入到生物信号的未受干扰的部分。快速脉冲是最常见的伪影，当插入一个或两个信号时，不会显著改变 PRx 指数。除等线漂移外，一个信号中存在的伪影在不到 5%的样本中超过 PRx 指数的阈值。相比之下，插入两个信号的最短矩形伪影在 55.4%的情况下将 PRx 改变为设定阈值以上的值。我们的分析表明，单个伪影对 PRx 指数的影响是可变的，取决于它们在一个或两个信号中的出现、持续时间和形状。这种不同的影响表明，可能并非所有的伪影都需要去除。
