Trial of real-time locating and messaging system with Bluetooth low energy

Hospital real-time location systems (RTLS) are increasing efficiency and reducing operational costs, but room access tags are necessary.

We developed three iPhone 5 applications for an RTLS and communications using Bluetooth low energy (BLE).

The applications were: Peripheral device tags, Central beacons, and a Monitor. A Peripheral communicated with a Central using BLE. The Central communicated with a Monitor using sockets on TCP/IP (Transmission Control Protocol/Internet Protocol) via a WLAN (wireless local area network). To determine a BLE threshold level for the received signal strength indicator (RSSI), relationships between signal strength and distance were measured in our laboratory and on the terrace.

The BLE RSSI threshold was set at -70 dB, about 10 m. While an individual with a Peripheral moved around in a concrete building, the Peripheral was captured in a few 10-sec units at about 10 m from a Central. The Central and Monitor showed and saved the approach events, location, and Peripheral's nickname sequentially in real time. Remote Centrals also interactively communicate with Peripherals by intermediating through Monitors that found the nickname in the event database.

Trial applications using BLE on iPhones worked well for patient tracking, and messaging in indoor environments.