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