Bio sensing is a technology
for the detection of a wide
range of chemical and
biological agents, including
bacteria, viruses and
toxins, in the environment
and humans.
A biosensor is an analytical device, used for the detection of an
analyte, that utilizes biological components e.g. enzymes to
indicate the amount of a biomaterial.
Example of a commercial biosensor is the blood glucose
biosensor,
• It uses the enzyme glucose oxidase to break blood glucose
down.
• it first oxidizes glucose and uses two electrons to reduce the
FAD (a component of the enzyme) to FADH2.
• This in turn is oxidized by the electrode (accepting two
electrons from the electrode) in a number of steps.
• The resulting current is a measure of the concentration of
glucose. In this case, the electrode is the transducer and the
enzyme is the biologically active component.
It consists of:
The sensitive biological element (e.g. tissue, microorganisms, organelles, cell receptors,
enzymes, antibodies, nucleic acids, etc.), a biologically derived material or biomimetic
component that interacts (binds or recognizes) the analyte under study.
The transducer or the detector element (works in a physicochemical way; optical,
piezoelectric, electrochemical, etc.) that transforms the signal resulting from the interaction of
the analyte with the biological element into another signal (i.e., transduces) that can be more
easily measured and quantified;
Biosensor reader device with the associated electronics or signal processors that are primarily
responsible for the display of the results in a user-friendly way.
Temperature
Accelerometers
Pressure sensors
Chemical
Biochemical
Resistance
Galvanic skin test
Glucose detection
Heart rate
Vital signs
Cochlear implants
Retinal implant
Cortical implant
Health monitoring
There are mainly two types of Biosensors:-
Physical Biosensors: Physical Sensors typically
monitors physiological signals such as breathing
rate, heart rate, ECG and temperature etc. They
convert physical properties into electrical signals.
Chemical Biosensors: Chemical sensors respond to
a particular analyte in a selective way through a
chemical reaction.
Sensing Methods and Applications
Biosensing methods can ben
divided in three groups:
Electrical-Electrical
sensing, such as bio-
potential, breath rhythm, and
sweat conductivity.
Electrochemical sensing, such
as pH or ions
(chloride, sodium, potassium, cal
cium, magnesium, etc.) in sweat.
Organic sensing, such as
protein detection in sore.
These can also be grouped by sensing groups and
methods, as shown in the following table.
Existing sensor technologies pose significant wearability problems
when integrated into the user's peri-personal space
These materials have a ubiquitous, constant-wear nature
Traditional technologies are rarely designed for continuous, on-body
use
Those that require skin contact are generally designed to be used in a
hospital or doctor's office
The achievement of certain design goals for existing sensors (such as
durability) is ultimately detrimental to the user's comfort when applied
to the wearable environment.
Textile-based sensors offer a compromise solution, by
retaining the characteristics associated with comfort and
wearability (properties of standard, non-electronic
garments)
Many textile-based sensors are actually sensing materials
used to coat a textile or sensing materials formed into
fibres and woven or knitted into a textile structure
The properties sought by textile-based sensors can
include flexibility, surface area, washability, stretch, and
hand (texture of textile)
To provide valuable information about the wearer’s health during their daily routine
To get the information about the wearer’s health within their natural environment
without interfering with his/her natural works
To provide remote monitoring of vitals signs
To perform diagnostics to improve early illness detection
Textile integrated sensors could measure a large variety of variables, e.g. physical
dimensions like pressure, stress and strain applied to the textile or biomedical
dimensions such as heart rate, electrocardiogram (ECG), sweat rate and sweat
composition (salts, pH), respiration rate or arterial oxygenation (SpO2) of the
monitored subject
Clothing having electronic or
electrochemical samples integrated in
them used to map critical physiological
parameters like heart rate, blood
oxygenation, pulse rate, core body
temperature, etc.
One of the most recent and exciting
category of medical clothing
Should support gathering of the measurable data
-should have good fit
-good skin contact of the electrodes
Should guide the electrodes to the correct positions
Should fulfill the requirements for the medical devices
Should be easy to use with good patient acceptance
Should be washable (atleast 30 times)
Should be easy to wear and remove
Should be comfortable to wear
- should be as light as possible
- should be non invasive to the normal working of the body
- skin friendly electrodes should be used
- garment should be designed in order to provide maximum comfort
- should not impede the ergonomic requirements of the user
- should have proper heat and moisture transport
Continued…..
Electrodes
Placement
Contact
Pressure
Movement
Body position
Integration (into clothing)
Recording context information for evidence
Microcircuits (e.g. accelerometer, temperature
sensor)
Thermogeneration
I. Situational analysis in determining the wearability
Understand the user
Understand the environment
Understand the activity
II. Body tolerance for pressure
Some areas of the skin surface are more sensitive to pressure than others are
In general, the fleshier part of the body will accept pressure more comfortably than areas where
bones are unpadded, particularly if the items causing the pressure are rigid and not shaped to
contour to the body surface
Female breasts, male genitals and the areas where major blood and lymph vessels and nerves
lie close to the surface
III. Factors affecting ease of motion in a garment
Flexibility, bulk, and weight of fabrics
Cut of garment: segment sizes and shapes
Flexibility of design: closures, design features and accessories etc.
Fit of garment
Frictional drag of fabric
IV. Stretch Fabrics
Stretch fabrics have the advantages of:
– maximum ease of mobility
– contouring to a wide variety of body shapes
Low modulus stretch fabrics have a disadvantage for wearable computers in that they
may not provide sufficient stability to hold heavier items in place on the body
Continued…..
Continued…..
V. Heat Dissipation
Thin, open-structured fabrics
Minimal layering (single layer main garment; fewer pockets, collarbands, trims)
Designs that provide minimal or loose coverage of the body
Loose, open areas around the head, neck and upper torso (heat rises)
Loose garment edges (armholes; cuffs; hems)
IV. Moisture transport
Continued…..
Heat is a “pump” that moves moisture in wickers. If the
environment is hotter than the body, moisture will be
pushed back toward the skin surface of the wearer.
Wickers only work if there is an absorbent material or an
air-filled environment beyond them into which the moisture
can escape.
V. Materials used:
Polyamide fibres, acrylic fibres, Polyurethane fibres, plastic optical fibres (POF), etc. are some of
the fibres that are currently being used in developing these clothings
Conductive yarn or textile wires made of Cu/Ag, pure steel thread, Ag coated polyamide filament
etc.
Other materials like foam, padddings, chemical sensors, etc. are also sometimes used
depending upon the application
Polypyrrole-coated conductive foam shows
considerable promise as a basic sensing
technology, and for use in detecting body
movements, physiological functions, and body
state from body-garment Interactions
It was found that increasing the weight placed
upon the PPy-PU foam or shortening the overall
length of the foam resulted in a proportional
decrease in the electrical resistance measured
across the foam in a linear fashion
The method used for sensor fabrication involved
soaking the substrate, the PU foam in an aqueous
monomer and dopant solution.
An aqueous oxidant solution is then introduced into
the reaction vessel to initiate polymerization.
This lead to the precipitation of doped PPy, which
subsequently deposited onto the PU substrate.
The effect of the PPy coating is to make the entire
foam conducting without compromising the soft,
compressible mechanical properties of the foam
substrate.
They produce heat
Are uncomfortable to wear
Sensitive to electromagnetic radiation
Susceptible to electrical discharges
Approach is based on thermoplastic silicone fibers, which can be integrated into woven
textiles.
As soon as pressure at a certain area of the textile is applied to these fibers they change their
cross section reversibly, due to their elastomeric character, and a simultaneous change in
transmitted light intensity can be detected.
A medicinal laser is used as a light source, having a FD-1 fiber (Medlight, Switzerland) and a
proprietary F-SMA coupler attached as an interface to the silicone fiber. The light energy was
measured with an Ulbricht integrating sphere (RW-3703-2; Gigahertz Optik, Germany).
A: Not reversibly bent or squeezed
B: Fully elastic case
LEDx = light emitting diodes;
Rx = light receiver (phototransistors)
Wearable
Detects the heart beat and externalize
it as pulses of light.
Sensors read the wearer's ECG and
produce flashes of light in time with
his/her own heart.
The heart beat rate can be monitored
by the Bluetooth signal.
Wearing the shirt gives an intense
feeling of life and rhythm, while at the
same time reminding the wearer his
electrical and mechanical roots.
New wireless technology for tele-home-care purposes gives new possibilities for monitoring of
vital parameters with wearable biomedical sensors, and will give the patient the freedom to be
mobile and still be under continuously monitoring and thereby to better quality of patient care
This is a new concept for wireless and wearable electrocardiogram (ECG) sensor transmitting
signals to a diagnostic station at the hospital, and this concept is intended for detecting rarely
occurrences of cardiac arrhythmias and to follow up critical patients from their home while they
are carrying out daily activities.
The wireless sensor is sticky and attached to the patient’s chest. It will continuously measure
and wirelessly transmit sampled ECG-recordings by the use of a built-in RF-radio transmitter.
Bio-Sensing Briefs to Track the Vitals
Researchers have developed a way to screen-print
electrochemical sensors onto fabric.
Nozzle-printed nano carbon electrode arrays using inkjet printers
like Epson NX420 AIO Inkjet Printer with 802.11n WiFi directly
onto the elastic bands of men’s underwear successfully.
The fixed contact to the skin will allow these biosensors to
constantly monitor hydrogen peroxide and the enzyme NADH
which are associated with various biomedical processes.
The invention of the smart underwear with biosensors is a reliable
and wearable physiological monitoring system that will allow 24/7
at-home surveillance of patients. This also decreases the workload
on the hospitals and will substantially reduce people’s medical
expenses.
Other Application areas
Clothing-integrated electrochemical sensors can also be used:
• To monitors alcohol consumption in drivers.
• To measures the performance and stress of both soldiers and athletes.
• To hold considerable promise for future healthcare, military or sport applications.
Sensing patches for monitoring of body fluids (e.g. sweat
rate, pH, electrolytes, etc.)
Prototype of passive pump for sweat collection and handling
(patented)
Patented technology for the integration of optical fibres into
elastic fabrics
Capacitive sensors for electro-physiological monitoring
Integration of electrodes, electronics and wiring in textiles
Clothing having physical biosensors:
• Physiological: High bulk, low moisture vapour transmission, high weight, etc.
• Environmental noise
• Motion artefacts: impediments in the normal working of the person
• Psychological: feeling of not looking good or looking odd
Clothing having chemical biosensors:
• Fluid movement control
• Calibration
• Wearability
• Safety
Textiles and clothing industries are not sufficiently engaged
No dedicated standards for testing smart textiles vs. reliability, robustness etc.
The customer/end user is rarely a part of the picture, needs and drivers are poorly
understood
Cost/added value issues are not sufficiently addressed
Core technologies e.g. interface, connectivity, sensing, skin
contact, transmission, manufacturing and usability are not sufficiently developed/tested
Research community still fragmented
Clothing for biosensing is a very new and a promising field of functional textiles
offering a solution to many sensing problems in medical analysis
Material selection, design, fit, comfort and non invasiveness are some of the most
important requirements of functional clothing
Although a no. of prototypes and products have been developed but the field has a
very large scope of research and development
The market constraints and the fragmented research community is a factor that is
impeding the progress of this clothing
1. www.kokeytechnology.com › Biotechnology
2. Shirley Coyle, Yanzhe Wu, King-Tong Lau, Sarah Brady, Gordon Wallace, Dermot Diamond, Bio-sensing
textiles - Wearable Chemical Biosensors for Health Monitoring, pp 35-38.
3. Simon Ekström, Chemical sensors and biosensors, Department of Electrical Measurements/Create Health.
4. http://produceconsumerobot.com/biosensing
5. health.ninemsn.com/fitness/exercise/695099
6. John G. Webster, Chapter 10. Chemical Biosensors, Robert A. Peura, Medical Instrumentation Application
and Design, 4th Edition, pp 449-495.
7. Rajiv Ranjan Singh, Preventing Road Accidents with Wearable Biosensors and Innovative Architectural
Design, Presented at 2nd ISSS NATIONAL CONFERENCE ON MEMS (ISSS-MEMS), 2007, CEERI,
PILANI.
8. Smart clothes: textiles that track your health by Bio-sensing textiles to support health management
(BIOTEX project)
9. Hee-Cheol Kim, Yao Meng and Gi-Soo Chung, Health Care with Wellness Wear, pp 42-59.
10. Markus Rothmaier 1,*, Minh Phi Luong 1 and Frank Clemens 2, Textile Pressure Sensor Made of Flexible Plastic
Optical Fibers, Sensors 2008, 8, 4318-4329; DOI: 10.3390/s8074318
11.Rune Fensli, Einar Gunnarson, Torstein Gundersen, A Wearable ECG-recording System for continuous
Arrhythmia Monitoring in a Wireless Tele-Home-Care Situation, Accepted for presentation at the 18th IEEE
International Symposium on Computer-Based Medical Systems, Dublin, June 23-24, 2005.
12.Lucy E Dunne*1, Sarah Brady2, Barry Smyth1 and Dermot Diamond2, Initial development and testing of a novel
foam-based pressure sensor for wearable sensing, Journal of NeuroEngineering and Rehabilitation 2005, 2:4
13.http://whisper.iat.sfu.ca/whisper_lit_review.htm
14.http://www.mat.ucsb.edu/~g.legrady/academic/courses/02w200a/wearable/index.html
15. Torsten Linz, Christian Dils, Reine Veiroth, Christine Karlmayer, Integrating electronics into textiles for wearable
electronics applications
16.Dr. Andreas Lymberis, Wearable and smart textile systems: EU Technology push or application pull, Avantex
2009, 16-18 June 2009
Continued…..
SUMIT SHARMA
Entry No. 2012TTE2413
VINAY INDORKER
Entry No. 2012TTE2397