Medtronic Patient Monitoring, Technopole Centre, Edinburgh, UK.
Medtronic Patient Monitoring, Boulder, CO, USA.
J Clin Monit Comput. 2023 Aug;37(4):1003-1010. doi: 10.1007/s10877-023-01003-7. Epub 2023 Apr 3.
Respiratory rate (RR) is one of the most common vital signs with numerous clinical uses. It is an important indicator of acute illness and a significant change in RR is often an early indication of a potentially serious complication or clinical event such as respiratory tract infection, respiratory failure and cardiac arrest. Early identification of changes in RR allows for prompt intervention, whereas failing to detect a change may result in poor patient outcomes. Here, we report on the performance of a depth-sensing camera system for the continuous non-contact 'touchless' monitoring of Respiratory Rate.
Seven healthy subjects undertook a range of breathing rates from 4 to 40 breaths-per-minute (breaths/min). These were set rates of 4, 5, 6, 8, 10, 15, 20, 25, 30, 35 and 40 breaths/min. In total, 553 separate respiratory rate recordings were captured across a range of conditions including body posture, position within the bed, lighting levels and bed coverings. Depth information was acquired from the scene using an Intel D415 RealSense camera. This data was processed in real-time to extract depth changes within the subject's torso region corresponding to respiratory activity. A respiratory rate RR was calculated using our latest algorithm and output once-per-second from the device and compared to a reference.
An overall RMSD accuracy of 0.69 breaths/min with a corresponding bias of -0.034 was achieved across the target RR range of 4-40 breaths/min. Bland-Altman analysis revealed limits of agreement of -1.42 to 1.36 breaths/min. Three separate sub-ranges of low, normal and high rates, corresponding to < 12, 12-20, > 20 breaths/min, were also examined separately and each found to demonstrate RMSD accuracies of less than one breath-per-minute.
We have demonstrated high accuracy in performance for respiratory rate based on a depth camera system. We have shown the ability to perform well at both high and low rates which are clinically important.
呼吸频率（RR）是最常见的生命体征之一，具有众多临床用途。它是急性疾病的重要指标，RR 的显著变化通常是潜在严重并发症或临床事件（如呼吸道感染、呼吸衰竭和心脏骤停）的早期迹象。及早发现 RR 的变化可以进行及时干预，而未能检测到变化可能导致患者预后不佳。在这里，我们报告了一种深度感应相机系统的性能，该系统用于连续非接触式“免触式”监测呼吸频率。
七名健康受试者进行了一系列呼吸频率为 4 至 40 次/分钟（次/分钟）的呼吸。这些设定的呼吸频率为 4、5、6、8、10、15、20、25、30、35 和 40 次/分钟。总共在各种条件下（包括身体姿势、床上位置、光照水平和床罩）捕获了 553 个独立的呼吸率记录。使用英特尔 D415 RealSense 相机从场景中获取深度信息。该数据实时处理，以提取与呼吸活动相对应的主体躯干区域的深度变化。使用我们最新的算法计算呼吸率 RR，并从设备中每秒输出一次，并与参考值进行比较。
在 4 至 40 次/分钟的目标 RR 范围内，实现了整体 RMSD 精度为 0.69 次/分钟，相应的偏倚为-0.034。Bland-Altman 分析显示，一致性界限为-1.42 至 1.36 次/分钟。还分别检查了三个单独的低、正常和高呼吸率亚范围，对应于<12、12-20、>20 次/分钟，每个亚范围都发现 RMSD 精度小于 1 次/分钟。
我们已经证明了基于深度相机系统的呼吸率具有很高的性能精度。我们已经证明了在高和低速率下都能很好地运行的能力，这在临床中很重要。
