Objective

This novel preliminary study sought to capture dynamic changes in heart rate variability (HRV) as a proxy for cognitive workload among perfusionists while operating the cardiopulmonary bypass (CPB) pump during real-life cardiac surgery.

Background

Estimations of operators’ cognitive workload states in naturalistic settings have been derived using noninvasive psychophysiological measures. Effective CPB pump operation by perfusionists is critical in maintaining the patient’s homeostasis during open-heart surgery. Investigation into dynamic cognitive workload fluctuations, and their relationship with performance, is lacking in the literature.

Method

HRV and self-reported cognitive workload were collected from three Board-certified cardiac perfusionists (N = 23 cases). Five HRV components were analyzed in consecutive nonoverlapping 1-min windows from skin incision through sternal closure. Cases were annotated according to predetermined phases: prebypass, three phases during bypass, and postbypass. Values from all 1min time windows within each phase were averaged.

Results

Cognitive workload was at its highest during the time between initiating bypass and clamping the aorta (preclamp phase during bypass), and decreased over the course of the bypass period.

Conclusion

We identified dynamic, temporal fluctuations in HRV among perfusionists during cardiac surgery corresponding to subjective reports of cognitive workload. Not only does cognitive workload differ for perfusionists during bypass compared with pre- and postbypass phases, but differences in HRV were also detected within the three bypass phases.

Application

These preliminary findings suggest the preclamp phase of CPB pump interaction corresponds to higher cognitive workload, which may point to an area warranting further exploration using passive measurement.

中文翻译：

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心脏外科灌注师与心肺旁路泵交互过程中认知工作量的动态变化分析

客观的

这项新颖的初步研究试图捕捉心率变异性 (HRV) 的动态变化，作为在现实心脏手术期间操作体外循环 (CPB) 泵时灌注师认知工作量的代表。

背景

操作员在自然环境中的认知工作量状态的估计是使用非侵入性心理生理学措施得出的。灌注师进行有效的 CPB 泵操作对于在心脏直视手术期间维持患者的体内平衡至关重要。文献中缺乏对动态认知工作量波动及其与绩效关系的调查。

方法

从三名委员会认证的心脏灌注师（ N = 23 例）收集 HRV 和自我报告的认知工作量。在从皮肤切口到胸骨闭合的连续非重叠 1 分钟窗口中分析了五个 HRV 成分。根据预定阶段对病例进行注释：旁路前、旁路期间的三个阶段和旁路后。对每个阶段内所有 1 分钟时间窗口的值进行平均。

结果

认知工作量在启动旁路和夹住主动脉之间的时间（旁路期间的预钳阶段）最高，并在旁路期间减少。

结论

我们确定了心脏手术期间灌注师中 HRV 的动态、时间波动，这与认知工作量的主观报告相对应。与旁路前和旁路后阶段相比，灌注师在旁路期间的认知工作量不仅不同，而且在三个旁路阶段也检测到 HRV 的差异。

应用

这些初步研究结果表明，CPB 泵交互的预钳阶段对应于较高的认知工作量，这可能表明需要使用被动测量进一步探索的领域。