无线健身和医疗监控系统的连通性选项

　　无线健身和医疗监控系统的连通性选项

　　由于健身监视器今天风靡一时，无线连接有许多不同的选择。针对消费者的健身带使用的是蓝牙低能量连接到智能手机的最新版本，但也有许多其他方式提供连接到健身带，也作为一个无线病人监护仪。

　　作为传感器平台本质上是相同的心跳和血压监测添加到一般的运动跟踪，长距离低功耗的无线链路可以提供显着更长的电池寿命为带，减少了需要补给系统，使更完整的数据捕获能力。这些可以与网关，它提供了一个恒定的链接，而不是依赖于手机的连接，提供了一个更可靠和完整的数据收集架构。这种可靠的无线链路变得越来越重要，因为数据可以直接发送到云存储和分析，而不是被下载时从显示器充电时。

　　As medical and fitness monitors do not require high data rate connections， the wireless link bandwidth can be traded for longer range and lower battery life， allowing significantly more data collection before the monitor needs recharging.

　　The Flex Gecko family of wireless controllers from Silicon Labs provides both 868 MHz sub-GHz and 2.4 GHz connectivity with the necessary encryption to protect the data. The 868 MHz links provide a long-range capability to link to a gateway for the collection of data. The chip combines an ARM® Cortex®-M4 controller core， 256 kB Flash， 32 kB RAM and 31 digital I/O pins to link to sensors as well as seven 16-bit timers and multiple communication interfaces. The transmitter provides a 20 dBm maximum output power and a receive sensitivity of -121 dBm at 2.4 kbps， using 2 GFSK encoding and a 0.1% bit error rate （BER）。 There are multiple low-power modes for different levels of operation that help to keep the power consumption to a minimum. This is particularly useful in a medical monitoring device that will wake up every few minutes to take readings and transmit them to the gateway， and then go back into an ultra-low power sleep mode. Figure 1 shows the different power modes， where the majority of the chip is kept dormant until required to transmit or receive data.