IEEE Trans Biomed Eng. 2024 Jul;71(7):2243-2252. doi: 10.1109/TBME.2024.3367536. Epub 2024 Jun 19.
This work explores Hall effect sensing paired with a permanent magnet, in the context of pulmonary rehabilitation exercise training.
Experimental evaluation was performed considering as reference the gold-standard of respiratory monitoring, an airflow transducer, and performance was compared to another wearable device with analogous usability - a piezoelectric sensor. A total of 16 healthy participants performed 15 activities, representative of pulmonary rehabilitation exercises, simultaneously using all devices. Evaluation was performed based on detection of flow reversal events and key respiratory parameters.
Overall, the proposed sensor outperformed the piezoelectric sensor with a mean ratio, precision, and recall of 0.97, 0.97, and 0.95, respectively, against 0.98, 0.90, and 0.88. Evaluation regarding the respiratory parameters indicates an adequate accuracy when it comes to breath cycle, inspiration, and expiration times, with mean relative errors around 4% for breath cycle and 8% for inspiration/expiration times, despite some variability. Bland-Altman analysis indicates no systematic biases.
Characterization of the proposed sensor shows adequate monitoring capabilities for exercises that do not rely heavily on torso mobility, but may present a limitation when it comes to activities such as side stretches.
This work provides a comprehensive characterization of a magnetic field-based respiration sensor, including a discussion on its robustness to different algorithm thresholds. It proves the viability of the sensor in a range of exercises, expanding the applicability of Hall effect sensors as a feasible wearable approach to real-time respiratory monitoring.
本研究探讨了霍尔效应感应与永磁体相结合在肺康复运动训练中的应用。
以呼吸监测的金标准——气流换能器为参考，对实验评估进行了考虑，并将其与另一种具有类似可用性的可穿戴设备——压电传感器进行了性能比较。共有 16 名健康参与者同时使用所有设备，完成了 15 项具有代表性的肺康复运动。评估基于流量反转事件和关键呼吸参数的检测。
总体而言，与压电传感器相比，所提出的传感器具有更高的性能，其平均比值、精度和召回率分别为 0.97、0.97 和 0.95，而压电传感器分别为 0.98、0.90 和 0.88。关于呼吸参数的评估表明，其在呼吸周期、吸气和呼气时间方面具有足够的准确性，呼吸周期的平均相对误差约为 4%，吸气/呼气时间的平均相对误差约为 8%，尽管存在一定的变异性。Bland-Altman 分析表明没有系统偏差。
所提出的传感器的特性表明，它具有足够的监测能力，适用于不太依赖于躯干运动的运动，但在侧伸展等运动时可能会受到限制。
本工作全面描述了一种基于磁场的呼吸传感器，包括对不同算法阈值下的传感器鲁棒性的讨论。它证明了传感器在一系列运动中的可行性，扩展了霍尔效应传感器作为实时呼吸监测的可行可穿戴方法的适用性。
