Abstract
The adoption of wearable systems in modern patient telemonitoring systems has been considered as a medical challenge towards the established medical practices, aiming at the highest level of quality of life. The current state-of-the-art technologies in wearable computing, wireless telemedical platforms and wireless sensors allow easy and unobtrusive electronic measurement of several vital signals and health conditions regardless the time and the place the patients need a condition monitoring. Certain major milestones to consider in the process of adopting wearable systems, besides the enabling technologies, are the affordability that depends on financial criteria, the adaptability of the overall healthcare sector to the innovative technologies and the conformance of the medical staff to the lifelong learning for vocational training. These aspects are discussed in this chapter, along with the description of the wearable systems capabilities and reference to their latest popular applications and future trends.
Top1. Introduction
The area of patient telemonitoring utilizing wearable devices is of particular importance and relevance during the last years. Monitoring of physiological and physical parameters may improve significantly the assessment and management of a patient health status, as it can contribute to the reduction of healthcare cost by avoiding unnecessary hospitalisations and ensuring the direct confrontation of emergency situations. Innovative wearable computer and software technologies are deployed to provide vital patient data monitoring and connect clinicians with patients using wearable computing technology via workstations, wireless devices and the Internet. Having realized the impact of this technology era to the healthcare industry, this chapter focuses on the e-health tools and practices related to wearable computing systems. The chapter investigates the current and future trends in this field through the adoption of wearable systems.
Wearable systems bring technology to patient care, ranging from prevention and diagnosis to follow-up, allowing the utilization of modern communication equipment and services. The goal is to link distant healthcare stations and individuals for the provision of healthcare services in real-time, allowing patient mobility. Unlike a laptop or a PDA, a wearable computer follows patients around and merges into the therapeutical processes and the human interactions. These devices not only allow long-term, continuous, and unobstructed monitoring of physiologic information, such as biopotential, photoplethysmogram (PPG), heart rate (HR), blood pressure (BP), blood oxygen saturation (SpO2), and respiration, but can also provide more realistic indication of the patient’s health status, and information that is otherwise inaccessible in clinical settings. By supporting online access to written information, anatomical maps, diagrams, photos, patient databases and allowing consultation with experts and peers through audio, video and text, the wearable computer can provide both doctors and patients with access to knowledge everywhere and in any situation. Enabling remote collaboration between doctor, nurse and other staff members, through wearable computers, should bring to faster, more efficient knowledge sharing and hence faster, more accurate, on-line higher standard performance. A typical architecture of electronic healthcare provision based on wearable systems and sensors is depicted in Figure 1.
Figure 1. A typical wearable system architecture
As it may be seen in Figure 1 a central node in the patient’s body is not prerequisite in every wearable infrastructure. Wireless communication infrastructure may be used for interconnecting the central node. The modern trend towards this direction is the formulation of patient Personal Area Networks, consisting of a wireless infrastructure of medical sensors, attached to patient's body, which lays the path for incessant telemonitoring of the person in mind, without discomforting them. The nature of data that these networks are set to handle, as well as the particular demands that patient telemonitoring services raise, necessitate for a thorough analysis of the design requirements of the networks communication protocols, in order to outflank possible disadvantages appearing in protocols for different types of wireless sensor networks, without putting aside simplicity and feasibility factors.
From the variety of fixed and mobile access techniques, according to assumed selection criteria, one can determine which technology to choose. Looking at both incumbent and emerging solutions, each medical party and patient may obtain as many benefits as necessary. When the scenario requires mobile telemetric of patients’ health, GSM or WLAN connections might be chosen. When medical specialists have to perform videoconference or live surgery coverage, they may utilize broadband techniques like POTS, xDSL or IP networks (LAN/WAN). Wireless LANs came to bridge the gap of applications like those that are described above. However, they are not limited to that small sector of science. More information regarding the networking modules of wearable systems are provided in Section 2.
The most popular biosignals incorporated in wearable systems are summarized in the table below (I. Maglogiannis and S. Hadjiefthymiades, 2007).
Key Terms in this Chapter
Medical Sensor: A device, such as a photoelectric cell, that receives and responds to a signal or stimulus
Vital Signs: The pulse rate, blood pressure, body temperature, and rate of respiration of a person. The vital signs are usually measured to obtain a quick evaluation of the person’s general physical condition
Telemonitoring: The science and technology of automatic measurement via medical sensors and transmissions of data by radio or other means from remote sources to receiving stations and analysis. Data transfer can be achieved via wireless communication means and or data transfer over other media, such as a telephone or computer network or via an optical link.
BSN: The term BSN is first coined by Prof Guang-Zhong Yang of Imperial College London in order to bring together scientists from different disciplines such as computing, electronics, bioengineering and medicine. The BSN node provides a suitable development platform for pervasive health care applications. Various physiological sensors can be integrated into BSN Node.
3G – 4G: 3rd and 4th-Generation wireless Internet devices. The major distinction of 4G over 3G communications is increased data transmission rates. 4G is expected to deliver more advanced versions of the same improvements promised by 3G, such as enhanced multimedia, smooth streaming video, universal access, and portability across all types of devices. 4G enhancements are expected to include worldwide Roaming capability and are likely to incorporate global positioning services (GPS). As was projected for the ultimate 3G system, 4G might actually connect the entire globe and be operable from any location on - or above - the surface of the earth.
Wireless Sensors: A wireless device that detects a change in a physical stimulus and turns it into a signal which can be measured or recorded.
E-Health: A relatively recent term for healthcare practice which is supported by electronic processes and communication. E-health encompasses a range of services that are at the edge of medicine/healthcare and information technology such as electronic medical records, telemedicine and evidence based medicine, m-Health and Health knowledge management. In a broader sense, e-health is an emerging field in the intersection of medical informatics, public health informatics and business, referring to health services and information delivered or enhanced through the internet and related technologies.
Bluetooth Wireless Technology: A worldwide specification for a small form factor, low cost radio solution that provide links between mobile computers, mobile phones, other portable handheld devices and connectivity to the internet.
Micro/Nano Electronics: A subfield of electronics related to the study and manufacture of electronic components made from semiconductors.
Wearable Systems: Defined as mobile electronic devices that can be always accessible and controlled by a user and can be unobtrusively embedded in the user’s outfit as part of the clothing or an accessory.
RFID: Stands for Radio Frequency Identification, RFID is an automatic identification method relying on storing and remotely retrieving data using devices calld RFID tags or transponders.
ZigBee: Specification for wireless personal area networks (WPANs) operating at 868 MHz, 902-928 MHz, and 2.4 GHz. A WPAN is a personal area network (a network for interconnecting an individual’s devices) in which the device connections are wireless. Using ZigBee, devices in a WPAN can communicate at speeds of up to 250 Kbps while physically separated by distances of up to 50 meters in typical circumstances and greater distances in an ideal environment. ZigBee is based on the 802.15 specification approved by the Institute of Electrical and Electronics Engineers Standards Association (IEEE-SA).