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  1. 1. 1 ABSTRACT Recent advancements in miniature devices have fostered a dramatic growth of interest of wearable technology. Wearable Bio-Sensors (WBS) will permit continuous cardiovascular (CV) monitoring in a number of novel settings. WBS could play an important role in the wireless surveillance of people during hazardous operations (military , firefighting , etc) or such sensors could be dispensed during a mass civilian casualty occurrence . They typically rely on wireless, miniature sensors enclosed in ring or a shirt. They take advantage of handheld units to temporarily store physiological data and then periodically upload that data to a database server via wireless LAN or a cradle that allow internet connection and used for clinical diagnosis.
  2. 2. 2 1. INTRODUCTION 1.1. BREIF HISTORY In 1916, first report on the immobilization of proteins adsorption of invertase on activated charcoal was published. Then in 1922, first glass pH electrode was introduced which was later leaded to the invention of oxygen electrode by Clarke. Later in 1962, first description of a biosensor as anamperometric enzyme electrode for glucose was identified by Clark. In 1969, first potentiometric biosensor was urease immobilized on an ammonia electrode to detect urea as diagnose. Then Bergveld invented the Ion-Selective Field-Effect Transistor (ISFET) which was one of the milestones in the history of Biosensors in Computer Science. In 1961 mathematicians Edward O. Thorp, and Claude Shannon built some computerized timing devices to help them cheat at the game of roulette. Thorp refers to himself as the inventor of the first "wearable computer". This work was kept secret until it was first mentioned in Thorp's book Beat the Dealer (revised ed.) in 1966 and later published in detail in 1969. In 1994 Edgar Matias and Mike Ruicci of the University of Toronto, debuted a "wrist computer." Their system presented an alternative approach to the emerging head-up display plus chord keyboard wearable. The system was built from a modified HP 95LX palmtop computer and a Half- QWERTY one-handed keyboard. With the keyboard and display modules strapped to the operator's forearms, text could be entered by bringing the wrists together and typing. The same technology was used by IBM researchers to create the half- keyboard "belt computer. Also in 1994, Mik Lamming and Mike Flynn at Xerox EuroPARC demonstrated the Forget-Me-Not, a wearable device that would record interactions with people and devices and store this information in a database for later query. It interacted via wireless transmitters in rooms and with equipment in the area to remember who was there, who was being talked to on the telephone, and what objects were in the room, allowing queries like "Who came by my office while I was on the phone to Mark?" As with the Toronto system, Forget-Me-Not was not based on a head-mounted display.
  3. 3. 3 In October 1997, Carnegie Mellon University, MIT, and Georgia Tech co-hosted the IEEE International Symposium on Wearables Computers (ISWC) in Cambridge, Massachusetts. The symposium was a full academic conference with published proceedings and papers ranging from sensors and new hardware to new applications for wearable computers, with 382 people registered for the event. Another early wearable system was a camera-to-tactile vest for the blind, published by C.C. Collins in 1977, that converted images into a 1024-point, 10-inch square tactile grid on a vest. In 2002, Dr. Bruce H Thomas and Dr. Wayne Piekarski developed the Tinmith wearable computer system to support augmented reality. This work was first published internationally in 2000 in the ISWC conference. The worked was carried out of the Wearable Computer Lab at the University of South Australia.In the late 2000s, various Chinese companies began producing mobile phones in the form of wristwatches, the descendants of which as of 2013 include the i5 and i6, which are GSM phones with 1.8 inch displays, and the ZGPAX s5 Android wristwatch phone.
  4. 4. 4 1.2. INTRODUCTION TO BIOSENSORS Wearable sensors and systems have evolved to the point that they can be considered ready for clinical application. The use of wearable monitoring devices that allow continuous or intermittent monitoring of physiological signals is critical for the advancement of both the diagnosis as well as treatment of diseases. Wearable systems are totally non-obtrusive devices that allow physicians to overcome the limitations of ambulatory technology and provide a response to the need for monitoring individuals over weeks or months. They typically rely on wireless miniature sensors enclosed in patches or bandages or in items that can be worn, such as ring or shirt. The data sets recorded using these systems are then processed to detect events predictive of possible worsening of the patient’s clinical situations or they are explored to access the impact of clinical interventions.
  5. 5. 5 2. DEVELOPEMENTOF WEARABLE BIOSENSORS 2.1. RING SENSOR It is a pulse oximetry sensor that allows one to continuously monitor heart rate and Oxygen saturation in a totally unobtrusive way. The device is shaped like a ring and Thus, it can be worn for long periods of time without any discomfort to the subject. The ring sensor is equipped with a low power transceiver that accomplishes the bidirectional communication with a base station, and to upload data at any point of time. 2.2. BASIC PRINCIPLE OF RING SENSOR Each time the heart muscle contracts, blood is ejected from the ventricles and a pulse of pressure is transmitted through the circulatory system. This pressure pulse when traveling through the vessels, causes vessel wall displacement which is measurable at various points in order to detect pulsatile blood volume changes by the photoelectric method, photo conductors are used. Normally the photo resistors are used for amplification purpose photo transistors are used. Light is emitted by LED and transmitted through the artery and the resistance of photo resistor is determined by the amount of light reaching it with each contraction of heart, blood is forced to the extremities and the amount of blood in the finger increases. It alters the optical density with the result that the light transmission through the finger reduces and the resistance of the photo resistor increases accordingly. The photo resistor is connected as a part of voltage divider circuit and produces a
  6. 6. 6 voltage that varies with the amount of blood in the finger. This voltage that closely follows the pressure pulse. The LEDs and PD are placed on the flanks of the finger either reflective or transmittal type can be used. For avoiding motion disturbances quite stable transmittal method is used. Transmittal type has a powerful LED for transmitting light across the finger. This power consumption problem can be solved with a light modulation technique using high-speed devices. Instead of lighting the skiing continuously, the LED is turned ON only for a short time, say 10-100 ns, and the signal is sampled within this period, high frequency, low duty rate modulation is used for preventing skin-burning problem. The motion of the finger can be measure with an optical sensor. This motion detector can be used not only for monitoring the presence of motion but also for cancelling the noise. By using PD-B as a noise reference, a noise cancellation filter can be built to eliminate the noise of PD-A which completes with the noise references used. An adaptive noise cancellation method is used.
  7. 7. 7 Fig 2.2 Prototype of Ring Sensor The ring has a microcomputer performing all the device controls and low level signal processing including LED modulation, data acquisition, filtering, and bi-directional RF communication. The cellular phone accesses a website for data storage and clinical diagnosis. 2.3. ARCHITECTURE OF RING SENSOR Fig 2.3 Block Diagram of Ring Sensor
  8. 8. 8 Power for light source, photo detector, RF transmitter and analog and digital processing units provided by a tiny cell battery used for wrist watches. Lifetime is 2 or 3 weeks. Light Source: Light source for the ring sensor is the LED, approximately wavelength of 660 nm. Photo Detector: Photo detector is normally photodiode or phototransistor used for detecting the signal from the LED. RF Transmitter: It is used for transmitting the measured signals. Its carrier frequency is 915MHz. LED Modulation: Power consumption problem can be solved with a lighting modulation technique. Instead of lighting the skin continually the LED is turned on only for a short time, say100-1000ns and the signal is sampled within the period. High frequency low duty cycle modulation implemented minimizes LED power consumption. Data Acquisition: It is used to collect the data from sensor and data are sampled and recorded. Filtering: The signal from the PD-B as a noise reference a noise cancellation filter can be built to eliminate the noise of PD-A that correlates with the noise reference signal. For noise cancellation we use the adaptive noise filter.
  9. 9. 9 3. SMART SHIRT (WEARABLE MOTHERBOARD) 3.1. INTRODUCTION Smart shirt developed at Georgia tech which represents the first attempt at relying an unobtrusive, mobile and easy to use vital signs monitoring system; presents the key applications of the smart shirt technology along with its impact on the practice of medicine; and covers key opportunities to create the next generation of truly “adaptive and responsive” medical systems. Research on the design and development of a smart shirt fort a combat casualty care has led to the realization of the world’s first wearable motherboard or an “intelligent” garment for the 21st century. The Georgia tech wearable motherboard (GTWM) uses optical fibers to detect bullet wounds and special sensors and interconnects to monitor the body vital signs during combat conditions. This GTWM (smart shirt) provides an extremely versatile framework for the incorporation of sensing, monitoring and information processing devices. The principal advantage of smart shirt is that it provides for the first time a very systematic way of monitoring the vital signs of humans in an unobtrusive manner. 3.2. REQUIREMENTS OF SMART SHIRT Casualties are associated with combat and sometimes are inevitable. Since medical resources are limited in a combat scenario, there is critical need to make optimum use of the available resources to minimize the loss of human life, which has value that is priceless. In a significant departure from the past, the loss of even a single soldier in a war can alter the nations engagement strategy making it all the important to save lives. Similarly on the civilian side, the population is aging and the cost of the health care delivery is expected to increase at a rate faster than it is today. With the decreasing number of doctors in rural areas, the doctor/patient ratio is in certain instances reaching unacceptable levels for ensuring a basic sense of security when
  10. 10. 10 they leave the hospital because they feel “cutoff” from the continuous watch and care they received in the hospital. This degree of uncertainty can greatly influence their postoperative recovery. Therefore there is a need to continuously monitor such patients and give them the added peace of mind so that the positive psychological impact will speed up the recovery process. Mentally ill patients need to be monitored on a regular basis to gain a better understanding of the relationship between their vital signs and their behavioral Fig 3.2 Requirements of Smart Shirt
  11. 11. 11 patterns so that their treatments can be suitably modified. Such medical monitoring of individuals is critical for the successful practice of telemedicine that is becoming economically viable in the context of advancements in computing and telecommunication, likewise continuous monitoring of astronauts in space, of athletes during practice sessions and in competition, of law enforcement personnel and combat soldiers in the line of duty are all extremely important. 3.3. ARCHITECTURE The GTWM was woven into a single –piece garment (an undershirt) on a weaving machine to fit a 38-40” chest. The plastic optical fiber (POF) is spirally integrated into the structure during the fabric production process without any discontinuities at the armhole or the segms using a novel modification in the weaving process.
  12. 12. 12 Fig 3.3 Block diagram of Wearable Motherboard An interconnection technology was developed to transmit information from (and to) sensors mounted at any location on the body thus creating a flexible “bus” structure. T-connectors –similar to “button clips” used in clothing are attached to the fibers that serve as a data bus to carry the information from the sensors (eg: ECG sensors) on the body. The sensors will plug into these connectors and at the other end similar Tconnector will be used to transmit their information for monitoring equipment or
  13. 13. 13 DARPS (Defense Advanced Research Projects Agency) personnel status monitor. By making the sensors detachable from the garments, the versatility Iof the Georgia Tech Smart Shirt has been significantly enhanced. Since shapes and sizes of humans will be different, sensors can be positioned on the right locations for all users and without any constraints being imposed by the smart shirt can be truly “customized”. Moreover the smart shirt can be laundered without any damage to the sensors themselves. The interconnection technology has been used to integrate sensors for monitoring the following vital signs: temperature, heart rate and respiration rate .In addition a microphone has been attached to transmit the weavers voice data to monitoring locations. Other sensors can be easily integrated into the structure. The flexible data bus integrated into the stricture transmits the information from the suite of the sensors to the multifunction processor known as the Smart shirt controller. This controller in turn processes the signals and transmit them wirelessly to desired locations (eg: doctor’s office, hospital, battlefield). The bus also serves to transmit information to the sensors (and hence the weaver) from the external sources, thus making the smart shirt a valuable information infrastructure. A combat soldier sensor to his body, pulls the smart shirt on, and attaches the sensors to the smart shirt. The smart shirt functions like a motherboard, with plastic optical fibers and other special fibers woven throughout the actual fabric of the shirt. To pinpoint the exact location of a bullet penetration, a “signal” is sent from one end of the plastic optical fiber to a receiver at the other end. The emitter and the receiver are connected to a Personal Status Monitor (psm) worn at the hip level by the soldier. If the light from the emitter does not reach the receiver inside the PSM, it signifies that the smart shirt has been penetrated (i.e.; the soldier has been shot). The signal bounces back to the PSM forum the point of penetration, helping the medical personnel pinpoint the exact location the solider wounds.
  14. 14. 14 The soldiers vital signs –heart rate, temperature, respiration rate etc. are monitored in two ways: through the sensors integrated into the T-shirt: and through the sensors on the soldier’s body, both of which are connected to the PSM. Information on the soldiers wound and the condition is immediately transmitted electronically from the PSM to a medical triage unit somewhere near the battlefield. The triage unit them dispatches the approximate medical personnel to the scene .The Georgia tech smart shirt can help a physician determine the extent of a soldiers injuries based on the strength of his heart beat and respiratory rate. This information is vital for accessing who needs assistance first during the so-called “Golden Hour” in which there are numerous casualties.
  15. 15. 15 4. DEVELOPEMENTOF BIOSENSING TECHNIQUES FOR ABCI APPLICATIONS 4.1. INTRODUCTION TO ABCI APPLICATIONS As the proliferation of technology dramatically infiltrates all aspects of social life, the development of strategies and techniques to enhance human–computer interfaces is becoming increasingly important. Recent developments in neuro-technologies are addressing these issues through novel concepts that directly link brain activity to computers. Major forerunners in this area are brain–computer interfaces (BCIs), which are based on a direct communication pathway between the human brain and an external device and have been primarily applied in laboratory and clinical settings. As bio sensing technologies continue to progress in the upcoming decades, the ability to image brain activity will move away from traditional BCI settings and into everyday environments. Such capabilities will enable the development of potentially revolutionary approaches that will alter the nature of how people interact with technology in their everyday environments through novel augmented BCIs (ABCIs), which are BCIs that can be used by individuals for everyday use.
  16. 16. 16 4.2. VARIOUS ABCI TECHNIQUES 4.2.1 WET SENSORS Conventional wet electrodes are the most frequently used sensors for measuring EEG signals. Many types of wet electrodes are available, and their individual characteristics and clinical applications have been widely studied. The various types include the following: 1) Disposable electrodes (pre-gelled types) 2) Reusable disc electrodes (gold, silver, stainless steel or tin) 3) Saline-based electrodes 4) Needle electrodes. For noninvasive multichannel measurements, electrode caps are preferred, which are placed on the surface of the user’s scalp. The most common wet electrodes are coated with Ag–AgCl and have a diameter of 1 to 3 mm with long, flexible leads that can be easily plugged into the readout circuit device. Ag–AgCl electrodes can accurately record small potential changes over relatively short durations. In contrast, needle electrodes are preferred for long recordings and are invasively inserted under the scalp. The development of effective and comfortable EEG sensors for everyday use requires the consideration of several factors, including 1) The ability to acquire high-quality signals from a wide range of individuals with different head shapes and sizes, hair types and lengths, and scalp properties (e.g., scalp toughening due to ultraviolet light exposure of balding areas or different chemical or soap residues associated with hygiene practices) 2) Long duration inter-application sensor stability, sensor attachment, and user comfort issues 3) The effects of long-term use (multiple acquisitions) on sensor stability/durability and the head/scalp
  17. 17. 17 4) Other practical considerations such as simplicity of application and cost. Additionally, the type and design of the electrode can have a significant impact on artifact signals. Novel Wet Approaches: Recently, Albaet al explored the benefits of a cross-linked polyacrylate gel at the electrode/skin interface. As a superabsorbent hydrogel, polyacrylate can absorb an electrolyte solution and swell to a degree far beyond typical contemporary electrode materials, providing a strong hydrating effect to the skin surface. This hydrating power allows the material to increase the effective skin contact surface area through wetting and noninvasively decreasing or bypassing the highly resistive barrier of the stratum corneum. Cross-linked sodium polyacrylate gel was synthesized using a method proposed by Sohnet al. The dimension of the polyacrylate gel electrode. The development of water-based sensors for EEG-based BCI applications was studied by Volosyaket al. This group has shown that water- based sensors can measure EEG activity using tap water as the interface to the scalp. However, movement artifacts, primarily influenced by the shape of the electrode, remain one of the major problems with such electrodes. This group has also concluded that optimal designs of the electrode and the electrode materials for maintaining low impedance still require future improvement. 4.2.2 DRY SENSORS With proper skin preparation and the use of conductive gels, the EEG signal quality from wet sensors is excellent. However, the skin preparation processes used to reduce the skin-electrode contact interface impedance can be time-consuming and uncomfortable for the user, making them impractical for everyday use. Furthermore, as the EEG signal quality may degrade over time as the skin regenerates and/or the conductive gel dries, these electrodes require repeated skin preparations and gel applications, which may also cause allergic reactions or infections. Issues also arise when measuring a location of interest that is covered with hair, which can lead to insufficient skin-electrode contact area, especially for long-term applications.
  18. 18. 18 To overcome these problems, dry-contact- and noncontact-type EEG sensors have been developed to improve EEG measurements. Dry contact sensor corneum and sometimes live skin layers, possibly resulting in pain or infection. These dry MEMS sensors can perform well in measuring EEG signals when applied to the forehead or other hairless sites; however, evidence regarding the quality of the EEG signals at sites covered with hair using dry MEMS-based EEG sensors is less convincing. Recently, fabric-based sensors were proposed for measuring biopotential signals. Beckmannet al.have conducted detailed investigations of the characterization of fabric materials with different fabric specifications for electrocardiography (ECG) measurements. Baeket al. contact probe EEG sensor for measuring EEG signals, especially at sites covered with hair. Each of the spring-loaded probes is used to attach the sensors tightly to the scalp surface. These probes were designed to be inserted into a thin plate for additional conductivity. Most importantly, this thin plate is flexible so that it will fit the scalp surface well when applying force to the sensor. The spring-loaded probes and thin plate serve as a buffer to avoid causing pain when force is applied to the sensor and to improve the skin-electrode contact impedance. An injection molding process is used to package the sensors, which can decrease the fabrication cost of the entire acquisition system, depending on the cost of the electrodes. Test results have demonstrated the feasibility of using dry spring-loaded probe electrodes for measuring EEG signals at sites covered with hair. Noncontact (capacitive) sensors with spaces between the electrode and the body and without skin preparation also have the potential to acquire EEG signals. However, dry capacitive sensors are sensitive to motion artifacts, and Gertet al. indicated that designing an amplifier to acquire signals with such high source impedance remains a challenging issue. Because of these issues, dry capacitive sensors require further improvement.
  19. 19. 19 Fig.4.2.2 Several types of EEG sensors: (a) wet sensors (b) water-based EEG sensors proposed by Volosyak (c)–(g) dry EEG sensors developed by Yu et al., Liao et al., Matthews et al., Grozea et al., and Liao et al. and (h) noncontact EEG sensors 4.2.3 NANO AND MICRO TECHNOLOGY SENSORS Nano electronic device technology holds promise for the next generation of electronics, leading to advancement through the development of novel sensors, flexible, transparent, and wearable high-performance electronics, smart bandages, optoelectronics, on-chip electronic-optical coupling, radiation hard electronics, and communications and processing electronics for deployable sensor platforms. For example, researchers in Spain and the United Kingdom have developed a new method for measuring electrical activity in the brain that uses sensors constructed from carbon nanotubes (CNTs). Ruffiniet al. also demonstrated the use of carbon-nanotube-based dry sensors in bio potential signal studies. In the future, active, short-range communication of information between body worn sensors may be enabled by spin- torque nano oscillators (STNOs). These devices are being actively studied as a technology for magnetic memory applications, and may also be used as miniature frequency-agile radio frequency (RF) sources and sensitive magnetic field detectors. For example, the extremely low-power (250 pW) transmission of microwave radiation
  20. 20. 20 through air has been demonstrated from a discrete 50-nm device, with broadband frequency agility over at least four octaves of frequency without conjugate matching, enabling a new class of low-power wireless communications for wearable sensor technologies. Bio-inspired nanotechnologies mimicking gecko foot structures are being developed as engineered reversible adhesive devices to enable mm- to cm-scale robotic platforms to crawl on surfaces and may be applicable to future biocompatible dry electrode adhesives for EEG sensors. Maturing micro- and nano electromechanical system (MEMS/NEMS) technologies also hold promise for novel actuation devices, tractors and state-measurement devices. In the future, carbon-based or other biocompatible nano scale sensing technologies may be envisioned that could be injected into blood vessels, cross the blood-brain barrier, attach to specific neurons or cells, sense the desired signals and transmit to an external receiver though the intact skull. While a very high spatial temporal resolution of the EEG signals could potentially be provided in this manner, the resolution of many significant technical and ethical considerations will be required to facilitate the use of such technologies, similar to the existing drug-development protocols.
  21. 21. 21 Fig 4.2.3 Wearable EEG devices: (a) Emotiv (b) NeuroSky (c) Zeo (d) StarLab (e) EmSense (f) nia Game Controller (g) Mindo 4 with dry foam electrodes and (h) Mindo 16 with dry spring-loaded probe sensors 4.2.4. MULTIMODALITY SENSORS In addition to those sensors that are only used to measure EEG signals, the simultaneous recording of hemodynamic responses using NIRS and neural activity using EEG through multimodality sensors while users receive stimulation is also a critical issue in the neuroscience domain. NIRS and EEG techniques are based upon different imaging principles, and therefore, cross-validation can improve our understanding of both the relationship between hemodynamic responses and neural activity underlying cortical activation and the biophysics behind the measurement techniques themselves. Furthermore and critical to ABCIs, simultaneous NIRS and EEG imaging can provide novel insight into the phenomenon of neurovascular coupling changes for studying human brain mapping in everyday environments. Takeuchi et al. developed a head cap for both NIRS and EEG whole-brain imaging, and neuro hemodynamic changes have been addressed in detail. Cooperet al. also proposed a novel probe design for simultaneous EEG and NIRS imaging of cortical activation in the human brain. To accomplish this imaging, anBopto-electrode probe was designed to house both an EEG electrode and an optical fiber bundle. This probe illustrates the potential applications of simultaneous NIR and EEG imaging. Although such novel ABCIs could provide simultaneous EEG and NIRS imaging, conductive gels and proper skin preparation are still required on the scalp skin surface at the electrode sites. In the future, we envision that dry EEG sensors will be integrated into simultaneous EEG and NIRS imaging.
  22. 22. 22 5. WEARABLE INTELLIGENT SYSTEMS FOR E-HEALTH 5.1. ELECTROCARDIOGRAM Non-contact wireless ECG sensors based on the principle of capacitive coupling are now becoming washable and fully integrated with clothing and wearable accessories. These wireless sensors overcome the shortcomings of traditional wet adhesive electrodes and can operate without directly contacting the skin surface. The sensors can be manufactured in the form of fabric by weaving or knitting conductive yarn/rubber/ink electrodes. In addition to arrhythmia, HR and heart rate variability (HRV) are also indicators of health. HR and HRV data can be extracted from ECG, PPG, remotely by microwave radar sensors based on the doppler effect and most recently by applying independent component analysis (ICA), a blind source separation method, on video images of people’s faces. 5.2. RESPIRATION Respiration is most commonly measured by sensors integrated into a belt or garment. The types of sensors used include impedance pneumo graphic, inductive plethysmo graphic, piezo resistive piezoelectric and textile-based capacitive sensors Respiration rate can also be extracted from other physiologicasignals such as ECG and PPG. 5.3. SpO The most popular method for non-invasive estimation of SpO is by means of photoplethysmography. The method is based on the difference in absorption of two wavelengths of light by the pulsatile arteriolar blood flow. Sensors have been integrated into finger rings, earlobe devices, foreheads, wristworn devices and shirts in wearable application. A wearable imaging device is also able to detect SpO2 and blood volume non-invasively by functional near-infrared (fNIR) spectroscopy.
  23. 23. 23 5.4. BLOOD GLUCOSE Diabetes is a common disease in the elderly population. In particular, sufferers of type I diabetes require daily BG measurements followed by insulin injections. These patients’ quality of life can be greatly improved by using feedback system with a small insulin pump to regulate the insulin delivery based on the measured BG levels. The system requires the patient’s glycemia to be measured accurately and continuously such that the insulin infusion rate and dosage can be adjusted accordingly. In recent years, several approaches for continuous monitoring have been developed, such as the subcutaneous needle sensor. It shows a needle-type glucose sensor used for a wearable artificial endocrine pancreas. This sensor is placed in the subcutaneous tissue and measures subcutaneous glucose concentration continuously. Another study reported a wearable glucose monitor based on SC open-flow microper fusion techniques, including handling of liquids, glucose sensors and electronics for motor control, sensor read-out, and communication. Nevertheless, the above methods are invasive. Advanced technologies for BG monitoring focus on needle free, transcutaneous measurements. A number of methods have been demonstrated to have great potential for the noninvasive and continuous monitoring of BG, e.g., by reverse iontophoresis, impedance spectroscopy, photoacoustic spectroscopy, near infrared spectroscopy, electrophoresis, enzyme-based direct electron transfer, some of which have been implemented in “watch-like” wrist-worn devices. 5.5. OTHER BIOCHEMICAL MEASUREMENTS In addition to BG, biochemical measurements of other body fluids, such as blood, sweat and urine, are also under active development. Real-time monitoring of the pH of sweat is usually performed using wearable micro-fluidic devices. The microchip was fabricated using polymer and can also be manufactured in textile form.
  24. 24. 24 5.6. BLOOD PRESSURE Hypertension is another common disease found in the elderly population. Elevated BP increases the workload of the heart and scars the artery walls. Increases in either BP or BP variability (BPV) are partly responsible for various cardiovascular events. Nevertheless, most individuals with hypertension experience no symptoms, which often make them overlook their ailment. Thus, early detection of BP for health condition assessment by wearable devices before a severe event occurs is very important. Technologies advanced in wearable BP monitoring focuses on continuous and noninvasive measurement without using a cuff. Cuff-less BP can be measured from the radial pulse waveform by arterial tonometry. Another promising technique for cuff-less BP is based on the estimation of PTT. Such technologies can be integrated with a personal capable of vital signs monitoring without causing deterioration of fabric behavior.
  25. 25. 25 6. APPLICATIONS OF BIOSENSORS 6.1. RING BIOSENSOR 1) In Catastrophe Detection: operations Eg: military, firefighting. 2) In chronic medical condition disease. 6.2. SMARTSHIRT • Combat casualty care. • Medical monitoring. • Sports/ Performance monitoring. • Space experiments. • Mission critical/ hazardous application. • Fire- fighting. • Wearable mobile information infrastructure. The vital signs information gathered by the various sensors on the body travels through the smart shirt controller for processing, from these, the computed vital signals are wirelessly transmitted using the “communication information infrastructure” in place in that application (e.g.: the firefighters, communication systems, battlefield communication infrastructure, the hospital network) to the monitoring station. There, the back-end Data display and Management system – with
  26. 26. 26 a built –in knowledge –based decision support system- in reverse these vital signs ask in real-time and provide the right response to the situation. Fig. 6.2. Applications of Smart Shirt 6.3. APPLICATIONS OF ABCIs Wet electrodes have their own readout circuit systems and are reliable for clinical applications. For dry/noncontact electrodes, developing the proper readout device for
  27. 27. 27 everyday use is important. Devices with dry electrodes are more convenient and comfortable than traditional EEG systems with wet electrodes and are, thus, more practical for use in everyday applications. Although dry/noncontact EEG devices have not been proposed or used for clinical applications, many commercial devices use EEG measurements for entertainment (Neurosky,Emotiv, StarLab, EmSense, and nia Game Controller) and for monitoring personal sleeping status (MyZeo). Devices with dry electrodes has become an important goal for mobile human brain imaging. Recently, Lin et al. proposed a wearable, wireless EEG device (Mindo) for everyday use. The Mindo 4 EEG device with 4-channel foam electrodes has proven to be reliable for controlling games according to the user’s mental focusing state based on signals from forehead sensor sites. It also has the potential to acquire the EEG status during sleep. Another multichannel EEG device, Mindo 16, which has spring-loaded probe electrodes, was designed by Lin et al. for wirelessly measuring EEG signals, especially at sites with hair, as the corresponding dry sensors have the potential to properly reach the scalp skin through the hair. In addition to wireless EEG devices with dry contact electrodes, Gert et al. designed a wireless device with non-contact electrodes for measuring both EEG and ECG. There is no doubt that developing a truly wearable, wireless EEG device using dry/noncontact electrodes and extending the limitations of this technique from basic research to clinical applications are important goals. Highly desirable characteristics of future devices include a minimized readout circuit size and easy preparation when using dry electrodes.
  28. 28. 28 6. FUTURE TRENDS 6.1. FUTURE TRENDS IN PERCEPTION OF SMARTSHIRT By providing the “platform” for a suite of sensors that can be utilized to monitor an individual unobtrusively. Smart Shirt technology opens up existing opportunities to develop “adaptive and responsive” systems that can “think” and “act” based on the users condition, stimuli and environment. Thus, the rich vital signs delta steam from the smart shirt can be used to design and experiment “real-time” feedback mechanism (as part of the smart shirt system) to embrace the quality of care for this individual by providing appropriate and timely medical inspections. Certain individuals are susceptible to anaphylaxis reaction (an allergic reaction) when stung by a bee or spider and need a shot of epinephrine (adrenaline) immediately to prevent above illness or even fatalities. By applying advancement in MEMS (Micro-Electromechanical Systems) technology, a feedback system including a dry delivery system-can be integrated in to the smart shirt. Of course mechanism to guard against inadvertent administration of dry can be built as a part of the control system. Likewise, the Smart shirt’s delta acquisition capabilities can be used to detect the condition when an individual is lapsing into a diabetic shock and this integrated feedback mechanism can provide the appropriate response to prevent a fatality. Thus, the smart shirt represents yet another significant milestone in the endeavor to save and enhance the quality of human life through the use of advanced technologies.
  29. 29. 29 6.2. FUTURE ABCI APPLICATIONS BASED ON ADVANCED BIOSENSING TECHNOLOGY Gaming control, homecare, and rehabilitation engineering applications are potential future applications of ABCIs in the coming decades. ABCI applications for gaming are one of the major focuses of this technology, and existing prototypes demonstrate the feasibility of games controlled by an ABCI. It is possible that an EEG based BCI device with novel EEG sensors that is capable of interpreting the cognitive relevance of neuron interactions in the brain will become available and reliable in the near future. Another feasible future trend for ABCIs is remote monitoring, which can be used in homecare and rehabilitation engineering applications. The elderly and ill often prefer living in their own houses to being in a hospital, but living alone can be dangerous because of unpredictable accidents such as falling and epileptic seizures. Remote-sensing and monitoring would enable the remote monitoring of a user’s EEG signals. EEG-based ABCIs may be able to assist with depression and many other psychological and cranial nerve diseases, such as schizophrenia, Parkinson’s disease and seizures, in the near future.
  30. 30. 30 7. CONCLUSION We have studied a wide range of approaches to ABCIs and explored their applications to neuro scientific questions and cognitive engineering. We have provided insights into the fundamental basis of many ABCI techniques and highlighted important considerations for their practical implementation. The miniaturization of sensors, electronics, and power sources; the design of power-efficient information processing; and the emergence of flexible electronics and display technologies have the potential to radically enhance future ABCI capabilities. We hope that these details will help those who are interested in using or developing bio sensing techniques for ABCIs to understand the key aspects that should be considered when acquiring measurements or analyzing data. We have surveyed the large body of literature that discusses studies in which bio sensing technologies and devices have been successfully used for ground-breaking and important research on ABCIs and their applications. The development of ABCIs is a rapidly expanding field that is continually evolving to embrace new technologies and real-life applications. The ring sensor and smart shirt are an effective and comfortable, and mobile information infrastructure that can be made to the individual’s requirements to take advantage of the advancements in telemedicine and information processing. Just as special-purpose chips and processors can be plugged into a computer motherboard to obtain the required information processing capability, the smart shirt is an information infrastructure into which the wearer can “plug in” the desired sensors and devices, thereby creating a system for monitoring vital signs in an efficient and cost effective manner with the “universal“ interface of clothing. The ring sensor is an effective, comfortable and mobile information infrastructure that can be made to the individual’s requirements to take advantage of the advancements in telemedicine and information processing. Wearable systems are totally non-obtrusive devices that allow physicians to overcome the limitations of ambulatory technology and provide a response to the need for monitoring individuals over weeks or months. Just as special-purpose chips and processors can be plugged into a computer motherboard to obtain the required information processing capability, the ring sensor is an information infrastructure into which one can “plug in” the desired sensors and devices, thereby creating a system for
  31. 31. 31 monitoring vital signs in an efficient and cost effective manner. Advanced technologies such as the smart shirt have at partial to dramatically alter its landscape of healthcare delivery and at practice of medicine as we know them today. By enhancing the quality of life, minimizing “medical” errors, and reducing healthcare costs, the patient-control wearable information infrastructure can play a vital role in realizing the future healthcare system. Just as the spreadsheet pioneered the field of information processing that brought “computing to the masses”. It is anticipated that the smart shirt will bring personalized and affordable healthcare monitoring to the population at large.
  32. 32. 32 8. REFERENCES [1] Y. Rajeshwari, T. Srilatha, “A Real –Time Continuous Monitoring of Health using Wearable Biosensors”, International Journal of Emerging Technology and Advanced Engineering, ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 3, Issue 9, September 2013 [2] Lun-De Liao, Alma E. Wickenden, Kaleb McDowell, Klaus Gramann, Tzyy-Ping Jung,Li-Wei Ko, anJyh-Yeong Chang, “Biosensor Technologies for Augmented Brain–Computer Interfaces in the Next Decades”, Proceedings of the IEEE, Vol. 100, May 13th, 2012, [3] Yuan-Ting Zhang, Carmen C. Y. Poon and Qing Liu, Hui Gao and WanHua Lin, “Wearable Intelligent Systems for E-Health”, Regular Paper Journal of Computing Science and Engineering, Vol. 5, No. 3, September 2011, pp. 246-256 [4] Masayuki Nakamura, Jiro Nakamura, Guillaume Lopez, Masaki Shuzo, Ichiro Yamada, “Collaborative Processing of Wearable and Ambient Sensor System for Blood Pressure Monitoring”, Sensors 2011, 11, 6760-6770; doi:10.3390/s110706760 [5] F. Benito-Lopez, S. Coyle, R. Byrne, and D. Diamond, “Sensing sweat in real- time using wearable microfluidics,” Proceedings of the 7th International Workshop on Wearable and Implantable Body Sensor Networks, Singapore, 2010. [6] Smart Shirt Biosensors http://www.smartshirt.gatech.edu [7] Wearable Biosensors http://www.en.wikipedia.org/wiki/Wearable_computer

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