Different Flavours of Bluetooth
New Bluetooth health devices are on their way that could help people manage their health and well-being. Let’s start by clarifying the terms and the technology:
Classic Bluetooth is a short-range radio technology commonly associated with hands-free operation of mobile phones. It’s optimised for streaming audio and not for long battery life. (It’s also called Bluetooth 2.0 or Bluetooth 3.0). So while some older personal health devices use Classic Bluetooth, the future lies with Bluetooth Low Energy.
Bluetooth Low Energy
This is a new technology that offers battery life measured in years. Confusingly, it’s also called Bluetooth 4.0 and Bluetooth Smart, and abbreviated as BLE. It’s present in newer phones, tablets and computers, where it operates in addition to Bluetooth Classic. Apple’s implementation is good, but not all Android makers support Bluetooth Low Energy well. The Bluetooth SIG has more details about Bluetooth Low energy.
For more in-depth coverage of the two Bluetooth flavours and technical comparisons, check out this paper.
Bluetooth Low Energy Personal Health Devices
The Bluetooth SIG publishes a list (incomplete?) of devices of all sorts that use Bluetooth Low energy. Manufacturers are not always clear about which flavour of Bluetrooth their devices use. A selection of devices includes:
- Withings blood pressure monitor
- Withings weighing scale
- iHealth pulse oximeter
- iHealth weighing scales
- Nonin pulse oximeter
- Propeller Health inhaler
A key to interoperability is standards – either formal standards from international standards organisations, or standards (more properly, “specifications”) set by industry bodies. The Bluetooth SIG has defined specifications for messages from some Bluetooth Low Energy device types, but not others. These specifications are called “Profiles” and they exist for these device types:
- Blood pressure monitors
- Blood glucose monitors
- Health thermometers
- Heart rate monitors
- Weighing scales (profile just published)
Missing from this list are:
- Pulse oximeters (coming soon)
- Medication adherence monitors
If device manufacturers adhere to the profile specifications of their device type then their device will send messages that can be understood by an app on a smart phone that is also written to that profile. This permits interoperability: a device from one manufacturer can be substituted by a device from another. (It remains to be seen whether device manufacturers do do this, or deliberately add custom features that prevent interoperability).