Tyndall National Institute, University College Cork, Dyke Parade, T12R5CP, Cork, Ireland.
Sanmina Corporation, 13000 S. Memorial Parkway, Huntsville, AL 35803, USA.
Sensors (Basel). 2020 Mar 17;20(6):1675. doi: 10.3390/s20061675.
A wristwatch-based wireless sensor platform for IoT wearable health monitoring applications is presented. The paper describes the platform in detail, with a particular focus given to the design of a novel and compact wireless sub-system for 868 MHz wristwatch applications. An example application using the developed platform is discussed for arterial oxygen saturation (SpO) and heart rate measurement using optical photoplethysmography (PPG). A comparison of the wireless performance in the 868 MHz and the 2.45 GHz bands is performed. Another contribution of this work is the development of a highly integrated 868 MHz antenna. The antenna structure is printed on the surface of a wristwatch enclosure using laser direct structuring (LDS) technology. At 868 MHz, a low specific absorption rate (SAR) of less than 0.1% of the maximum permissible limit in the simulation is demonstrated. The measured on-body prototype antenna exhibits a -10 dB impedance bandwidth of 36 MHz, a peak realized gain of -4.86 dBi and a radiation efficiency of 14.53% at 868 MHz. To evaluate the performance of the developed 868 MHz sensor platform, the wireless communication range measurements are performed in an indoor environment and compared with a commercial Bluetooth wristwatch device.
提出了一种用于物联网可穿戴健康监测应用的基于手表的无线传感器平台。本文详细描述了该平台，特别关注用于 868 MHz 手表应用的新型紧凑无线子系统的设计。讨论了使用所开发平台的示例应用，用于使用光学光体积描记法 (PPG) 测量动脉血氧饱和度 (SpO) 和心率。在 868 MHz 和 2.45 GHz 频段比较了无线性能。这项工作的另一个贡献是开发了一种高度集成的 868 MHz 天线。天线结构使用激光直接结构化 (LDS) 技术打印在手表外壳的表面上。在 868 MHz 下，模拟结果显示吸收率比最大允许限值低 0.1%。测量的体上原型天线在 868 MHz 时具有-10 dB 阻抗带宽为 36 MHz、峰值实现增益为-4.86 dBi 和辐射效率为 14.53%。为了评估开发的 868 MHz 传感器平台的性能，在室内环境中进行了无线通信范围测量，并与商用蓝牙手表设备进行了比较。
