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
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.
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
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.
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
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
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
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
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.
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
2.3. ARCHITECTURE OF RING SENSOR
Fig 2.3 Block Diagram of Ring Sensor
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 for the ring sensor is the LED, approximately wavelength of 660 nm.
Photo detector is normally photodiode or phototransistor used for detecting the signal
from the LED.
It is used for transmitting the measured signals. Its carrier frequency is 915MHz.
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.
It is used to collect the data from sensor and data are sampled and recorded.
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.
3. SMART SHIRT (WEARABLE MOTHERBOARD)
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
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
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
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.
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
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 sensors will plug into these connectors and at the other end similar
Tconnector will be used to transmit their information for monitoring equipment or
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.
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.
4. DEVELOPEMENTOF BIOSENSING TECHNIQUES FOR ABCI
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.
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
3) The effects of long-term use (multiple acquisitions) on sensor stability/durability
and the head/scalp
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
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.
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.
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
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
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.
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.
5. WEARABLE INTELLIGENT SYSTEMS FOR E-HEALTH
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.
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.
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.
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.
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
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
6. APPLICATIONS OF BIOSENSORS
6.1. RING BIOSENSOR
1) In Catastrophe Detection:
operations Eg: military,
2) In chronic medical condition
• 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
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
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.
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.
6.2. FUTURE ABCI APPLICATIONS BASED ON ADVANCED BIOSENSING
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.
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
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
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Yamada, “Collaborative Processing of Wearable and Ambient Sensor System for
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 Smart Shirt Biosensors http://www.smartshirt.gatech.edu
 Wearable Biosensors http://www.en.wikipedia.org/wiki/Wearable_computer