蓝牙低能简介

在我们的两部分系列的第一个系列中，我们正在探索蓝牙低能的背景以及它如何改变连接的医疗设备的世界。

The Internet of Things (IoT) has brought about new applications for connected devices. Manufacturers are moving beyond headsets and keyboards. One of these new use cases stands out in particular: applications that rely less on continuous streaming and periodically relay small amounts of data instead. This is especially true in sensor applications where a remote peripheral is relaying information about its surroundings — such as a thermostat, security sensor, or a medical monitoring device. At the same time, an advance in the Bluetooth standard is making these new applications possible.

蓝牙经典和蓝牙低能的简短历史

Bluetooth feels like it has been around forever. In fact, the original specification was released in 1998 and the first hands-free headsets appeared on the market in 1999. Since then, it’s been used to connect everything from computer mice and keyboards to portable speakers and headphones. Bluetooth Classic, as it’s now called, covers a range of 79 channels and can transmit up to 3Mb/s up to 50 meters — making it useful for data transmission, streaming audio, and sharing pictures with other smartphones, among other things.

虽然许多使用蓝牙经典的设备都是电池操作的（至少是外围设备），但电源绝不是问题 - 因为组件的设计用于易于充电和更换电池。您的计算机鼠标的电池是否仅持续了几天都没关系。您可以插入充电电缆或换电池。毕竟，原始的802.11规格每秒携带2兆位（MB/s），随后的802.11b仅适用于11 Mb/s。这使Bluetooth Classic的3MB/S对相对较广泛的应用具有吸引力。

为了支持一种新的部署模型，该模型的设备可能会在电池互换之间进行更长的时间，甚至几年，行业发展起来，以设计新的低功率通信标准。诺基亚在2010年首次针对该目标制定了早期协议规范。该诺基亚规格由蓝牙特别兴趣组（SIG）采用，并标准化为蓝牙低能（BLE），作为蓝牙4.0协议的一部分。BLE协议使用的是蓝牙经典的2.4 GHz ISM频带，但在频率差异频谱方面具有不同的方案 - 以及其他一些重要差异。

BLE标准已经出现以支持较低的带宽率，范围从125 kb/s到2 MB/s，包括新的无连接模式，除了以连接为导向的经典模式。BLE中最大的进步是省力的重点。默认情况下，BLE外围设备睡觉直到准备传输数据为止。结合在较低数据速率的传输过程中，使用较低的功率利用率结合使用，BLE设备的功耗通常仅是使用Bluetooth Classic的设备的1-5％。它们的功率排在15-20微型的范围内，这意味着标准的按钮电池可以为多年来的大多数设备提供动力。

重塑医学互联网

Reasonable data transfer rates coupled with low power consumption make BLE devices attractive for consumer applications, such as headphones and thermostats, but that’s only part of the story. Those same attributes also make BLE ideal for connected medical devices—otherwise known as the Internet of Medical Things (IoMT). A glucose monitor, for example, can use BLE to relay glucose levels to a smartphone for convenient monitoring. In a hospital setting, inexpensive BLE tags attached to devices can make inventory tracking and location much easier. Moreover, BLE’s support for large numbers of connected peripherals makes it even more valuable in a clinical or hospital setting, which may involve hundreds (or thousands) of connected medical devices. Think about a nurse’s monitoring station, for example. With BLE, you can have all the floor’s ECGs and other patient monitoring devices relaying telemetry information to a central place. It's the same idea behind health-related wearables such as heart monitors and fitness watches — all of which relay pulse information over BLE.

用电缆，笨重的电池和启用智能手机通信分发是向前迈出的一步。但是，与任何创新一样，存在不可避免的风险。在医疗设备的情况下，这些风险不仅会导致不便，例如音频质量降低或电池寿命。当涉及到IOMT时，设备风险会直接危害患者的安全。

在下一部分中，我们将讨论与医疗设备快速采用BLE通信的一些风险。你可以阅读这里。