LoRa, IoT for medical devices?
More and more household and medical devices are connected to the internet, either for added functionality or because the main functionality of the device depends on the internet. Currently the most used connection method for these portable devices is using a point-to-point protocol like bluetooth, z-wave, zigbee or Wi-Fi, in combination with a device that can act as a gateway such as a router or smartphone.
This method is not only limited in portability since the gateway device needs to be in range and operating, but also consumes a lot of power and could become costly (when using a 3G/4G smartphone). An alternative low-power approach where the device can connect to an ISP directly would be beneficial for some devices.
New communication protocols and infrastructure are currently in development with initiatives such as LTE-M1, NB-IoT, SigFox, Dash7 and the one I’m addressing: LoRa in combination with LoRaWAN. LoRa is mostly used in and around the Netherlands for now, probably because one of the partners in the program is KPN who already facilitates a nationwide network (currently in test phase) and because of The Things Network, an initiative for a crowd-sourced global network.
The LoRa system could provide a power efficient and low-cost solution for on-site communication, such as in and around a hospital or city area. In the near future, it could become a solution for nation-wide or even global IoT communication.
LoRa uses a spread spectrum radio signal at 868-870Mhz to provide low-bandwidth communication and is intended for devices that incidentally need to communicate in small amounts, such as street lighting, coffee machines, ventilation systems, power grids, trucks, etc.
It could very well be applied in medical devices. A hospital bed that sends its location and status, a scale that reports your weight as soon as you stand on it, or a blood glucose sensor that reports the level every few minutes. The low-bandwidth in combination with a complete package of signal improvement measures makes that it handles noise and obstructions better than most other protocols.
Wireless technologies are already widespread in medical applications and are even used within the operating theatre. Of course there are risks involved in using any wireless technology, maybe even more so when using free bands as LoRa does. It is vital to address all potential patient risks induced by using a wireless communication system appropriately as you would for any other patient risk. On top of that there are several guidance documents available, such as “Radio Frequency Wireless Technology in Medical Devices - Guidance for Industry and Food and Drug Administration Staff” from the FDA. For instance, one of the aspects that this highlights is wireless coexistence. The earlier mentioned signal improvement measures together with appropriate testing will help reducing coexistence risks to acceptable levels.
The public network coverage depends on the area where you want to deploy. However, public coverage is not the only consideration in the choice for LoRa. One of the strengths of LoRa is the possibility to deploy cheap private gateways to form your own network, with a coverage of up to 3km per gateway. This allows for in-building communication with the use of a single gateway, suitable for a lot of solutions that would be impossible with other, more established, technologies.
Whether LoRa is a good fit for your solution depends on your needs and roadmap. We currently see it as one of the possible tools to use in a new connected solution.
For this blog I used the following sources and I would recommend reading them to find out more about LoRa:
After finishing my education I directly started in the field of Medical Software Development. In the context of Zentis I held various technical roles in all sorts of projects, among which software architect and team lead. While always being f...