Heart rate variability (HRV), using electrocardiography (ECG), has gained popularity as a biomarker of the stress response. Alternatives to HRV monitoring, like photoplethysmography (PPG), are being explored as cheaper and unobtrusive non-invasive technologies. We report a new wireless PPG sensor that was tested in detecting changes in HRV, elicited by a mentally stressful task, and to determine if its signal can be used as a surrogate of ECG for HRV analysis. Data were collected simultaneously from volunteers using a PPG and ECG sensor, during a resting and a mentally stressful task. HRV metrics were extracted from these signals and compared to determine the agreement between them and to determine if any changes occurred in the metrics due to the stressful task. For both tasks, a moderate/good agreement was found in the mean interbeat intervals, SDNN, LF, and SD2, and a poor agreement for the pNN50, RMSSD|SD1, and HF metrics. The majority of the tested HRV metrics obtained from the PPG signal showed a significant decrease caused by the mental task. The disagreement found between specific HRV features imposes caution when comparing metrics from different technologies. Nevertheless, the tested sensor was successful at detecting changes in the HRV caused by a mental stressor.

中文翻译：

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在耳垂上使用无线蓝牙光电体积描记器传感器进行验证，以监测健康个体在诱发压力的心理任务期间的心率变异性。

使用心电图（ECG）的心率变异性（HRV）作为压力反应的生物标记物已获得普及。目前正在探索替代HRV监测的替代方法，例如光体积描记法（PPG），以作为更便宜且不引人注目的非侵入性技术。我们报告了一种新的无线PPG传感器，该传感器经过测试可检测出由精神紧张的任务引起的HRV变化，并确定其信号是否可用作ECG进行HRV分析的替代物。在休息和精神紧张的任务中，使用PPG和ECG传感器同时从志愿者那里收集数据。从这些信号中提取了HRV指标并进行比较，以确定它们之间的一致性，并确定由于压力大的任务指标是否发生任何变化。对于这两项任务，在平均心跳间隔中均发现了中等/良好的一致性，SDNN，LF和SD2，对于pNN50，RMSSD | SD1和HF指标的一致性较差。从PPG信号获得的大多数经过测试的HRV指标显示出明显的减少是由于脑力劳动引起的。在比较不同技术的指标时，在特定的HRV功能之间发现的分歧迫使我们谨慎行事。但是，经过测试的传感器可以成功检测出由精神压力导致的HRV变化。