title: Trial of real-time locating and messaging system with Bluetooth low energy.
abstract: BACKGROUND
  Hospital real-time location systems (RTLS) are increasing efficiency and reducing operational costs, but room access tags are necessary.
  
  
  OBJECTIVE
  We developed three iPhone 5 applications for an RTLS and communications using Bluetooth low energy (BLE).
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Trial applications using BLE on iPhones worked well for patient tracking, and messaging in indoor environments.
authors.affiliation: Department of Medical Informatics, School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa, Japan.
authors.forename: Naoya
authors.initials: N
authors.lastname: Arisaka
authors.affiliation: Department of Medical Informatics, School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa, Japan.
authors.forename: Noritaka
authors.initials: N
authors.lastname: Mamorita
authors.affiliation: Department of Physiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
authors.forename: Risa
authors.initials: R
authors.lastname: Isonaka
authors.affiliation: Department of Physiology, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Kawakami
authors.affiliation: Department of Medical Informatics, Kitasato University School of Medicine, Sagamihara, Kanagawa, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Takeuchi
mesh_terms: D006739:Hospital Administration; D006801:Humans; D008122:Local Area Networks / Q000295:instrumentation*; D063731:Mobile Applications; D010355:Patient Identification Systems / Q000379:methods*; D000068997:Smartphone; D059015:Wireless Technology / Q000295:instrumentation*
keywords: Bluetooth low energy; Real-time location system; iPhone application