Wearable Biosensors

Name: Nandhini B N

USN: 4gw09cs406

Guide:

Contents Introduction Need for a wearable biosensor What is Wearable Biosensor Components of a Biosensor Ring Sensor Smart Shirt Applications Future trends Conclusion References

Introduction

Use of wearable monitoring devices allow continuous

monitoring of physiological signals

Wearable systems are totally non-obtrusive devices that allow

physicians to overcome the limitations of ambulatory

technology

Detects events predictive of possible worsening of

the patient’s clinical situations

Need for a wearable biosensor

Remote monitoring of patients

Training support for athletes

Monitoring of individuals who work with hazardous elements

Tracking of professional truck driver’s vital signs to alert them of fatigue

What is wearable biosensor ?

Wearable Biosensor = Wearable + Biosensor

Biosensor is an analytical device used for detection of analyte.

e.g. Blood Glucose Detector

Biosensor

Object that can be worn on body.

e.g. wrist watches, ring, shirts etc.

Wearable

Wearable Biosensor

Wearable monitoring devices that allow continuous monitoring of physiological signals.

They rely on wireless sensors enclosed in items that can be worn, such as ring or shirt.

The data sets recorded using these systems are then processed to detect patient’s clinical situations.

Biosensor is an analytical device, which converts a biological response into electrical signal.

Components Of Wearable Biosensor

Three main components of wearable biosensors are:

Biological element: For sensing the presence and concentration of a substance.

Transducer: The product of interaction of biological component and sample may be a suitable chemical, charge etc., which can be converted by transducer into an electrical signal.

Associated Electronic Devices: The electrical signal may be further amplified and can be read on digital panels

Types Of Wearable Biosensor

Ring Sensor:

It allows one to continuously monitor heart rate and oxygen saturation. The device is shaped like a ring.

Smart Shirt:

This technology has been used to integrate sensors for monitoring the vital signs like temperature, heart rate and respiration rate.

About Ring SensorIt is a pulse oximetry, i.e.

it monitors the oxygen saturation.It is based on the concept of photoconductor.

Principles :-

Blood pressure pulse causes vessel wall displacement.

Detection pulsatile blood volume changes by photoelectric method by photo resistor

Connected as a part of voltage divider circuit and produces a voltage that varies with the amount of blood in the finger.

Components:

• LED’s and Photodiodes• Optical sensor unit• PIC microcontroller• RF transmitter• Tiny cell battery• Use of double ring structure.• First stage amplifier• Signal Conditioner• Sample and hold circuit

Less distance between LED & PD.

Waveforms sampled at 100 Hz transmitted to a PDA or a cellular phone carried by the patient.

Working Of Ring Sensor

In order to detect blood volume changes due to heart contraction and expansion by photoelectric method, normally photo resistors 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.

Oxygenated blood absorb more light than deoxygenated blood

A noise cancellation filter is used to cancel the noise due to motion of the finger.

Applications Wireless supervision of people during hazardous operations.

In an overcrowded emergency department.

Chronic surveillance of abnormal heart failure.

In cardio-vascular disease for monitoring the hyper tension.

Advantages Continuous

monitoring.

Easy to use.

Reducing

hospitalization fee

Disadvantages Initial cost is high.

Limited number of

physiological parameters can

be monitored.

About Smart Shirts

Also known as GTWM i.e. Georgia Tech Wearable Motherboard.

This GTWM (smart shirt) provides an extremely versatile framework for the incorporation of sensing, monitoring and information processing devices.

• It uses optical fibers to detect bullet wounds and special sensors and interconnects to monitor the body vital signs during combat conditions.

• It is used to integrate sensors for monitoring the vital signs like temperature, heart rate and respiration rate.

Working of Smart Shirt

A combat soldier sensor to his body, pulls the smart shirt on, and attaches the sensors to the smart shirt.

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.

Information on the soldiers wound and the condition is immediately transmitted electronically from the PSM to a medical unit.

Applications Of smart shirtCombat casualty care.Medical monitoring.Sports/ Performance monitoring.Space experiments.Mission critical/ hazardous application.Fire- fighting.Wearable mobile information infrastructure.

Advantages   Continuous monitoring.

Right Treatment at the right time

Easy to wear and takeoff.

Disadvantages

Initial cost is high

Battery life is less

Conclusion

Applied to restricted area of potential market.

Limitations: Sensitivity And battery life.

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.

It is leading to the realization of “Affordable Healthcare, Any place, Anytime, Anyone”.

  H.Harry Asada, “Mobile monitoring with wearable ppg sensors”,IEEE

engineering in medicine and biology magazine, vol 22, pp- 28-39 may/june 2003.

Park and Jayaraman,”Enhancing the quality of life through wearable technology”, IEEE engineering in medicine and biology magazine,vol 22, pp- 41-48 may/june 2003.

Handbook of biomedical instrumentation ,Khandpur ,pp-138,233,238

R.Neuman,”Biomedical sensors”, handbook of biomedical instrumentation,pp-725-755

http://www.smartshirt.gatech.edu http://www.wearables.gatech.edu

References