Nordic-powered Bluetooth LE insulin management system helps patients monitor diabetic therapy


EOFlow’s EOPatch uses Nordic’s nRF52832 for wireless connectivity between wearable, controller and smartphone app

Nordic Semiconductor today announces that Korea-based medical device company EOFlow has selected Nordic’s nRF52832 Bluetooth® 5.2/Bluetooth Low Energy (Bluetooth LE) general-purpose multiprotocol System-on-Chip (SoC) to provide the wireless connectivity for its ‘EOPatch’ insulin management system. The solution is designed to help diabetic patients improve their quality of life by allowing them to monitor and manage their diabetes therapy. 

EOPatch is a 49.5 by 39 by 14.5mm, 29.4g (excluding insulin), IPX8 waterproof (1m for 24 hours), tubeless, wearable, and disposable insulin pump integrating a Nordic nRF52832 SoC. The unit continuously delivers insulin under the skin via a soft canula, helping control blood glucose levels in diabetic patients who need basal insulin and periodic injections of bolus insulin. The reservoir holds up to 200 U (2ml) of insulin, with at least 80 U of insulin needed to activate the patch. In addition, the EOPatch insulin management system comprises a controller that connects to the iOS and Android compatible ‘EOBridge’ Cloud-based diabetes data management program via the ‘EOCloud’ server. 

The ultra-low power consumption was the key hardware feature behind our decision to use Nordic’s nRF52832 SoC for the EOPatch solution, while the Nordic nRF SDK and secure OTA-DFU functionality were the key software features
Kyungho Park, EOFlow

Bluetooth LE connectivity

Once the EOPatch is filled with insulin, attached and activated, the patient can use either the ‘ADM’ (Advanced Diabetes Manager) smart touchscreen remote controller, or the ‘Narsha’ Android app on a Bluetooth 4.0 (and later) smartphone to control and deliver insulin from the patch. The remote controller or smartphone communicate with the EOPatch via Nordic SoC-enabled Bluetooth LE connectivity. The functionality of the controllers enables the appropriate amount of basal or bolus insulin required to be calculated based on the user’s current blood glucose level, IOB (insulin on board), carbohydrate intake, and other personally programmed settings. Using the controller and the EOBridge app/web platform, the user can create optimized insulin delivery programs and patterns, monitor past insulin deliveries, check blood glucose levels, and view other diabetes-related data.

The EOPatch wearable insulin pump unit employs two LR44 alkaline batteries enabling continuous use for up to three-and-a-half days prior to disposal, thanks in part to the ultra low power characteristics of the Nordic SoC. The nRF52832 has been engineered to minimize power consumption with features such as the 2.4GHz radio’s 5.5mA peak RX/TX currents and a fully-automatic power management system that reduces power consumption by up to 80 percent compared with Nordic’s nRF51 Series SoCs.

Nordic’s nRF52832 SoC combines a 64MHz, 32-bit Arm® Cortex® M4 processor with floating point unit (FPU), with a 2.4GHz multiprotocol radio (supporting Bluetooth 5, ANT™, and proprietary 2.4GHz RF protocol software) featuring 4dBm output power -96dBm RX sensitivity for a link budget of 100 dBm, with 256/512kB Flash memory and 32/64kB RAM. 

The nRF Connect SDK [Software Development Kit] integrates the Zephyr RTOS, supports applications using Bluetooth LE, Bluetooth mesh and Thread, and includes examples, Bluetooth LE profiles and driver support for all peripherals. The SDK also includes a migration of Nordic’s Bluetooth SoftDevice Controller from the company’s proven SoftDevices used with the nRF52 Series. The nRF5 SDK can still be used for development with Nordic’s S132 SoftDevice, a Bluetooth 5-certifed RF software protocol stack for building advanced Bluetooth LE applications. 

Superior power consumption

“The ultra-low power consumption was the key hardware feature behind our decision to use Nordic’s nRF52832 SoC for the EOPatch solution, while the Nordic nRF SDK and secure OTA-DFU [over-the-air device firmware update] functionality were the key software features,” says Kyungho Park, Head of Software Engineering HQ at EOFlow. “Nordic’s fast response times through the Nordic DevZone forum proved very helpful during product development.”