IoT-Integrated BLE-Based Real-Time Data Link and Beamforming Phased Array for Healthcare

This article presents a novel approach to vagus nerve stimulation (VNS) therapy for epilepsy treatment, introducing a phased array antenna (PAA) system integrated with Bluetooth low energy (BLE) technology. The system comprises an implantable VNS receiver (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Rx</i>) and an external transmitter (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Tx</i>) based on a 1 × 2 PAA configuration, operating at 2,450 MHz. Additionally, an advanced 1 × 4 PAA system is employed to further optimize beam-steering capabilities. Dynamic beamforming is achieved through digital phase shifters. The integration of a commercial BLE-based radio frequency (RF) microcontroller facilitates seamless communication and control. Simulations and experimental verifications of 1 × 2 and 1 × 4 PAA systems are conducted to verify the performance. Measured peak gains of 2.63 dBi and 5.39 dBi are achieved by 1 × 2 PAA and 1 × 4 PAA with a −10 dB bandwidth of 100 and 330 MHz, respectively at the BLE band. Real-time measurements of received signal strength indicators in diverse environments, including free-space (−54 dBm), tissue-mimicking saline gel (−42 dBm), and live animal subjects (−79 dBm), substantiate the practicality of beamsteering and communication within the BLE-enabled PAA system. To the best of our knowledge, this is the first study to develop a BLE-based communication and beamforming RF PAA system for biomedical applications.