Bluetooth LE glucose monitoring system provides continuous blood sugar level data for two weeks before replacement


SiBionics’ GS1 CGM System uses Nordic’s nRF52832 SoC to provide wireless connectivity between diabetes wearable sensor and smartphone

Nordic Semiconductor today announces that Shenzhen, China-based healthcare technology developer, SiBionics, has selected Nordic’s nRF52832 Bluetooth® 5.2/Bluetooth Low Energy (Bluetooth LE) general purpose multiprotocol System-on-Chip (SoC) to provide the core processing power and wireless connectivity for its ‘GS1 Continuous Glucose Monitoring (CGM) System’. 

GS1 CGM System is designed to enable patients with Type 1 diabetes, and those with Type 2 diabetes who are dependent on insulin or oral medications, to continuously monitor and record their interstitial fluid glucose levels in real time for up to fourteen days before replacement. The system automatically generates ambulatory glucose profile (AGP) for reference during medical consultation, and it won’t affect the patient’s everyday activities such as swimming or exercise.

The solution employs a sterilized disposable electrochemical sensor—applied to the user’s upper arm by a minimally invasive method—to measure glucose levels in interstitial fluid (the body fluid between blood vessels and cells). In addition to providing reliable 24-hour glucose values, the solution detects glucose trends and aids in the detection of episodes of hyperglycemia (high blood glucose) and hypoglycemia (low blood glucose) that are not easily detected by traditional monitoring methods. 

Nordic’s nRF52832 SoC is an ideal choice for our GS1 CGM System because it provides low power consumption, stable Bluetooth LE connectivity, and generous Flash memory which is important for data use and storage
Mingsong Han, SiBionics

In operation, the GS1 CGM System uses an integrated transmitter to convert electric signals to digital signals (following a process of signal amplification and filtering) and relay the data to the user’s Bluetooth 4.0 (and later) smartphone using the Bluetooth LE connectivity provided by the Nordic SoC. From their smartphone, users can then monitor their glucose values through the associated iOS/Android ‘SiJoy’ app. This information can also be shared with medical professionals, via a Cloud-based dashboard for blood glucose management, either remotely or at the hospital. 

Continuous low power operation

The device is powered by a disposable low-power coin cell battery that provides sufficient power to operate continuously for fourteen days, 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. 

The nRF52832 SoC integrated in the GS1 CGM System provides both the wireless connectivity to the transmitter, and the processing power for the device’s functionality. The nRF52832 SoC’s 64MHz, 32-bit Arm® Cortex® M4 processor with floating point unit (FPU) provides ample computational power to run the complex sensor algorithms that convert the sensor data from the transmitter into the blood glucose value displayed on the companion app. 

Nordic’s nRF52832 SoC combines the Arm Cortex M4 processor with a 2.4GHz multiprotocol radio (supporting Bluetooth 5.2, ANT™, and proprietary 2.4GHz RF protocol software) featuring -96dB RX sensitivity, with 512kB Flash memory and 64kB RAM.

The nRF Connect SDK [Software Development Kit] is recommended for nRF52832 software development. The nRF Connect SDK 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.

Stable connectivity and generous Flash

“Nordic’s nRF52832 SoC is an ideal choice for our GS1 CGM System because it provides low power consumption, stable Bluetooth LE connectivity, and generous Flash memory which is important for data use and storage,” says Mingsong Han, Executive Vice President, SiBionics.