Abstract
This work describes the work-in-progress aimed at the design of a telemedicine system that is intended to give support to the physicians in critical scenarios and keep a record of the patient status within all the evacuation chain. The authors call this system a Patient Tracking System (PTS). The hardware/software platform described will integrate the services and functionalities available from the existing e-health infrastructure and provide the physicians with a decision support system in remote and hard-to-reach areas. The main goal is building a simple network hierarchy relying on two kinds of mobile devices: 1) a low-power Medical Information Carrier (MIC), and 2) an MDA (Medical Digital Assistant). A MIC is a device intended to hold personal medical information that may be accessed by a physician through a specialized terminal (the MDA) and, when suitably programmed, may emit a beacon signal to allow patient tracking along the evacuation chain. It is anticipated that our design will contribute to improve the efficiency in the use of communication resources in telemedicine. In a more general way, this project should enhance our understanding of the limitations that hardware and software impose on the operation in critical scenarios.
Top2. Technological Issues In Pts Design
The design of a PTS is not an easy task since it implies the integration of several technologies ranging from Very Large Scale Integration (VLSI) technologies for implementing the Medical Information Carrier (MIC), to Information and Communication Technologies (ICT), for implementing support software and firmware to allow the MIC to communicate to the outside world and to build-up mesh networks with other similar devices, and to implement the software interface with the existing e-health infrastructure.
The main goals of a PTS are: (1) improving and speeding up the quality of diagnostics, and (2) supporting medical personnel, rescuers and first responders in their tasks, namely, the prevention of disease, treatment of sick and injured patients, and patient evacuation and hospitalization. A great effort is being carried out to develop wireless systems that keep a record of patient status during all the evacuation chain, for both military and civil applications (Penwill, 2008; Swedberg, 2006). Penwill (2008) reports a wireless dog-tag derived from the Personal Information Carrier (PIC) developed by Physical Optics Corporation. The device is intended to keep the medical record of a soldier, and may be accessed through an IEEE 802.15.1 (Bluetooth) wireless link with no tracking capability. Swedberg (2006) describes the Belgian Victim Tracking and Tracing Systems (BeViTTS). This system has been derived from the Dutch VTS (Victim Tracking System) and relies on a Wi-Fi (IEEE 802.11) RFID active tag. The tag is stored into a bracelet, whose colour identifies patient status (for example, black for “dead”, red for “urgent care required”, etc.).
Key Terms in this Chapter
Ad Hoc Wireless Network: A wireless ad hoc network is a decentralized wireless network in which the network itself emerges from the collective effort of all the nodes. Consequently, each node acts also as a router and must be aware of network topology and connectivity. Due to the mobile nature of the network nodes, the determination of which nodes forward data is made dynamically based on the network connectivity.
WPAN: A wireless personal area network (WPAN) is a network that allows the communication among devices close to one person (typically in the range between few meters and few tenths of meters). Such kind of network may rely on technologies such us Ultra Wide Band (UWB), Bluetooth, or ZigBee.
WLAN: A wireless local area network (WLAN) is a network that allows communication among several computers or devices within a limited area. Most WLANs rely on the IEEE 802.11 standards (Wi-Fi).
MAC: The Medium Access Control (MAC) is a sublayer of the Data Link Layer specified in the OSI model. It acts as an interface between the Logical Link Control (LLC) sublayer and the network physical layer (PHY).
ZigBee: ZigBee is the name of a suite of high level communication protocols targeted to cheap, low-power, and long battery lifetime Wireless Personal Area Networks (WPANs) and relying on digital radios based on the IEEE 802.15.4 standard. The technology is intended to be simpler and cheaper than other WPANs, such as Bluetooth.
PHY: The Physical Layer (PHY) is the first layer of the OSI model for network computing. The PHY layer is the fundamental layer underlying all the logical layers and network abstractions and comprises the basic hardware transmission technologies of a network.
FPGA: A field-programmable gate array (FPGA) is a semiconductor device containing programmable logic components called logic blocks, and programmable interconnects. Both logic blocks and interconnect may be programmed “on-the field” allowing the possibility to map onto a single chip several designs.
Transceiver: A transceiver is a device that has both a transmitter and a receiver which are combined and share common circuitry or are hosted on the same chip.