Despite the importance of respiration and metabolism measurement in daily life, they are not widely available to ordinary people because of sophisticated and expensive equipment. Here, we first report a straightforward and economical approach to monitoring respiratory function and metabolic rate using a wearable piezoelectric airflow transducer (WPAT). A self-shielded bend sensor is designed by sticking two uniaxially drawn piezoelectric poly l-lactic acid films with different cutting angles, and then the bend sensor is mounted on one end of a plastic tube to engineer the WPAT. The airflow sensing principle of the WPAT is theoretically determined through finite element simulation, and the WPAT is calibrated with a pulse calibration method. We prove that the WPAT has similar accuracy (correlation coefficient >0.99) to a pneumotachometer in respiratory flow and lung volume assessment. We demonstrate metabolism measurement using the WPAT and the relationship between minute volume and metabolic rates via human wear trials. The mean difference of measured metabolic rates between the WPAT and a Biopac indirect calorimeter is 0.015 kcal/min, which shows comparable performance. Significantly, unlike the Biopac indirect calorimeter with an airflow sensor, an oxygen gas sensor, and a carbon dioxide gas sensor, we merely use the simple-structured WPAT to measure metabolism. Thus, we expect the WPAT technology to provide a precise, convenient, and cost-effective respiratory and metabolic monitoring solution for next-generation medical home care applications and wearable healthcare systems.

中文翻译：

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用于人体呼吸和代谢监测的可穿戴压电气流传感器

尽管呼吸和新陈代谢测量在日常生活中很重要，但由于设备复杂且昂贵，普通人无法广泛使用它们。在这里，我们首先报告了一种使用可穿戴式压电气流传感器 (WPAT) 监测呼吸功能和代谢率的直接且经济的方法。采用两片单轴拉伸压电多晶硅贴片设计了一种自屏蔽弯曲传感器- 具有不同切割角度的乳酸薄膜，然后将弯曲传感器安装在塑料管的一端以设计 WPAT。通过有限元仿真从理论上确定了WPAT的气流传感原理，并采用脉冲标定法对WPAT进行了标定。我们证明 WPAT 在呼吸流量和肺容量评估方面与呼吸速度计具有相似的准确性（相关系数 > 0.99）。我们展示了使用 WPAT 进行的新陈代谢测量，以及通过人体磨损试验证明分钟通气量与新陈代谢率之间的关系。WPAT 和 Biopac 间接量热仪测得的代谢率的平均差异为 0.015 kcal/min，这表明性能相当。值得注意的是，与带有气流传感器、氧气传感器的 Biopac 间接量热仪不同，和二氧化碳气体传感器，我们仅使用结构简单的 WPAT 来测量新陈代谢。因此，我们期望 WPAT 技术能够为下一代医疗家庭护理应用和可穿戴医疗保健系统提供精确、方便且具有成本效益的呼吸和代谢监测解决方案。