Medical-grade Bluetooth 5/Bluetooth LE-powered wearable provides in-depth user activity data for clinical trials and academic health research

ActiGraph watch

The ActiGraph ‘CentrePoint Insight Watch’ employs Nordic Semiconductor’s nRF52832 WL-CSP SoC to deliver high-throughput wireless connectivity in ultra-compact package 

Nordic Semiconductor today announces that Pensacola, FL-based ActiGraph, a leading provider of medical-grade wearable activity and sleep monitoring solutions, has selected Nordic’s nRF52832 Bluetooth® 5/Bluetooth Low Energy (Bluetooth LE) System-on-Chip (SoC) to provide the wireless connectivity for its ‘CentrePoint Insight Watch’. The watch is designed to provide activity feedback to organizations conducting clinical trials, as well as academic health researchers.

The water resistant CentrePoint Insight Watch comes in a smartwatch form factor with a backlit date/time display and a push button interface. It employs a triaxial MEMS accelerometer to capture and record continuous, high-resolution raw acceleration data, providing detailed feedback on the individual’s activity intensity, energy expenditure, steps taken, and sleep efficiency. The watch employs Nordic’s nRF52832 Wafer Level Chip Scale Package (WL-CSP) SoC to periodically transmit the data from the device to the company’s CentrePoint Cloud platform,

The nRF52832 WL-CSP SoC’s Bluetooth 5 support—including 2x on-air raw data bandwidth (2Mbps) and an improved channel coexistence algorithm—enables the watch to rapidly and wirelessly transmit large amounts of data quickly (and return to a power saving sleep mode). Such functionality extends battery life and limits inconvenience to patients caused by recharging.

The CentrePoint Insight Watch’s 210mAh Li-Poly battery can provide up to 40 days of continuous use between recharge with wireless connectivity enabled and a download of approximately 10MB of data per day, thanks in part to the ultra low power consumption of the Nordic chip. 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 is a clear leader in this space, and because ActiGraph is constantly operating on the ‘bleeding edge’ of this technology, Nordic is a good fit
Jeremy Wyatt, ActiGraph.

Data is transferred from the watch across the high-throughput Bluetooth LE wireless link to a Rigado BMD-340 module (powered by a Nordic nRF52840 Bluetooth 5/Bluetooth LE SoC) integrated into a charging cradle. The cradle is in turn connected to the CentrePoint Data Hub (CDH), a cellular network-enabled home gateway, via a USB connection. Alternatively, data can be sent via a patient-facing smartphone or tablet app (due for release early 2019). From there, information is sent to the CentrePoint Cloud platform.

The CentrePoint Cloud platform provides clinical trial sponsors and researchers with the ability to remotely monitor and manage subject data, wear compliance, identify potential data trends, as well as generate customized data reports, and manage audit trails. A CentrePoint application programming interface (API) also makes it possible to integrate ActiGraph data directly into a client’s own proprietary or third-party electronic data capture (EDC) platform.

The nRF52832 WL-CSP SoC measures just 3.0 by 3.2mm and forms a powerful multiprotocol solution ideally suited for Bluetooth LE and 2.4GHz ultra low-power wireless applications, while offering all the features of the conventionally packaged SoC. The nRF52832 combines an 64MHz, 32-bit Arm® Cortex™ M4F processor with a 2.4GHz multiprotocol radio (supporting Bluetooth 5, ANT™, and proprietary 2.4GHz RF software) featuring -96dB RX sensitivity, with 512kB Flash memory and 64kB RAM.
The WL-CSP SoC is supplied with Nordic’s S132 SoftDevice, a Bluetooth 5-certifed RF software protocol stack for building advanced Bluetooth LE applications. The S132 SoftDevice features Central, Peripheral, Broadcaster and Observer Bluetooth LE roles, supports up to twenty connections, and enables concurrent role operation.

“Key to our decision to select the nRF52832 WL-CSP SoC was its very early support of the increased data rates of Bluetooth 5, but we also chose the chip due to its size, price, availability, and functionality,” says Jeremy Wyatt, Chief Technology Officer and Senior VP of Product Development, ActiGraph.

“Nordic is a clear leader in this space, and because ActiGraph is constantly operating on the ‘bleeding edge’ of this technology, Nordic is a good fit. We look forward to a continued partnership with Nordic as we push the envelope in terms of raw data transfer to help our clients develop and utilize digital biomarkers.”