Final Report

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Name of the University, City

Department of Biomedical Engineering

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S Y N O P S I S

Of the Mini Project entitled

EMOTIONAL STRESS INDICATOR (ESI) KIT

proposed to be submitted

under subject of

xxxx at

Name of the college, city

By

xxxxxxxxxx

Teacher: xxxx

DEPARTMENT OF BIOMEDICAL ENGINEERING

S Y N O P S I S

ON

EMOTIONAL STRESS INDICATOR (ESI) KIT

xx (Roll no. xx)xxx (Roll no. xx)xxxx (Roll no. xx)

Teacher: Mrs. xxx

BACKGROUND INTRODUCTION:

Stress is a popular topic these days. There is rarely a week that passes

without hearing or reading about stress and its deleterious effect on health.

The word `stress` is defined by the Oxford Dictionary as "a state of affair

involving demand on physical or mental energy”[1]. Another definition

stress refers to the “consequence of the failure of

an organism – human or animal – to respond appropriately

to emotional or physical threats, whether actual or imagined”[2].

Work-related stress and mental fatigue – mainly blamed on expectations of

better performance, deadlines and competition – is taking a toll on Indian

employees indifferent sectors.

A survey conducted by India’s industry body Assocham has revealed that

“the menace of stress and mental fatigue has intensified in recent times at

the top and middle positions of sectors comprising construction, shipping,

banks, government hospitals, trading houses, electronic and print media,

courier companies, small-scale industries, retail and card franchise

companies.”[3]

These sectors are becoming high-stress zones like the business process

outsourcing (BPO), call centers and IT companies because of deadlines,

demand for high performance, shortage of staff and threats from

competitors. A survey by a NGO, Saarthak claims that among 30 companies

50 per cent of the employees had stress in some form, 20 per cent had

depression and 30 per cent had problems like alcoholism, marital discord,

etc. So, the condition of stress is quiet astounding in India [4].

Measuring stress level independent of differences in people’s personalities

has been inherently difficult. There is no way to measure stress directly, but

we can get an indication of the levels of stress in the body by measuring

some of the physical affects in the body which are affected by stress Best

way to measure stress is with medical equipment that measure[5] :

1. Heart rate

2. Blood pressure

3. Breathing rate

4. Brain waves

5. Muscle tension

6. Skin resistance

7. Temperature

Most of the methods listed above are either expensive or inaccurate due to

interference of factors other than stress. Thus a straight forward method

and inexpensive for measuring emotional stress is highly required.

CURRENT DEVICES

There are several ways of measuring stress and here are few most

commonly used stress measurement techniques used today.

Nipro Corcoro Meter®, the saliva stress

detector

Yamaha Motor Co. collaborated with Nipro Corp.

and researchers at Toyama University to develop a

gadget that can measure a person's stress level

from their saliva. The stress detection gadget

works by measuring amylase, a digestive enzyme

found in saliva. The concentration tends to increase when a person is under

stress. Yamaha aims to commercialize the system within a year, and expects

it to be used by research institutions [6].

emWave Personal Stress Reliever®

Fig.1 Nipro Corcoro Meter, the saliva stress detector front panel.[6]

The emWave Personal Stress Reliever is an

innovative approach to stress management based

on learning to change the heart rhythm pattern

and create physiological coherence in the body.

This gadget helps the clients to learn internal

awareness, self-regulation and emotional

management skills. They can learn to reduce

stress and increase health and wellness by becoming aware of when the

stress response starts and by stopping it in the moment [7].

Stress Indicator by VoicePrism™

Stress Indicator by VoicePrism™ is the first consumer

software working on Windows OS and Windows

Mobile handheld devices, that can help discover the

causes of stress through vocal analysis. Stress

Indicator measures stress in five key parts of your

life: home, work, love, friends and plans. It measures

stress by using mathematical formulas to

identify measure and analyze the patterns in the

frequencies of the human voice. These patterns allow Stress Indicator to

glean insights into a person's emotional and mental states.[8]

PROJECT OVERVIEW:

Our goal is to design an Emotional Stress Indicator (ESI) kit that allows you

access your emotional pain. If the stress is very high, it gives visual

indication through LED display along with a warning beep.

Fig.3 Stress Indicator by VoicePrism™ display screen on Windows Mobile handheld device.[8]

Fig.2 emWave Personal Stress Reliever kit.[7]

It is based on the principle that the resistance of the skin varies in

accordance with your emotional states. Resistance varies inverse

proportional to the stress. If the stress level is high the skin offers less

resistance, and if relaxed resistance is high. The low resistance of the skin

during high stress is due to increase in the blood supply of the skin. This

increases the permeability of the skin and hence the conductivity of electric

current. This property of the skin is used here to measure the stress level.

Fig.4 shows a block diagram of the ESI kit. The touch pads of the stress

meter sense the voltage variations across the touch pads and convey it to

the signal amplifier, followed by LED display for visual indication and a

warning beep. The circuit is very sensitive and detects even a minute

voltage variation across the touch pads.

Fig.4 Block Diagram of Emotional Stress Indicator (ESI) Kit

CIRCUIT DIAGRAM

Fig.5 Emotional Stress Indicator (ESI) Kit Schematic Diagram

ELECTRONIC COMPONENTS/DEVICES REQUIRED

S.no

Name of the Electronic Component/Device

Specifications

Quantity

1. National Semiconductor IC 3915

IC LM 3915 1

2. Fairchild Semiconductor Transistor

BC 548 1

3. Zener Diode 5.1V, 0.5W 14. Diode 1N4148 15. Piezoelectric buzzer 1

6. ON/OFF switch 17. Touch Pads (Self-locking

pads)1

8. Transparent LEDs (3mm) Green LEDYellow LEDRed LED

212

9. Duracell Battery 9V 110. Potentiometers 1MΩ

47KΩ11

11. Resistors 560E470E47KΩ1KΩ1.2KΩ

12111

12. Capacitors 10µF, 16V 100µF, 16V

12

13. Connecting Wires14. Perforated Board 1

Fig.6 PIN DIAGRAM OF LM 3915 DISPLAY DOT/BAR DRIVER [9].

Fig.7 Self Locking Straps ( with touch pads)

Fig.8 Display Panel on ESI Kit

Fig.9 Final ESI Kit

Fig.10 Breadboard implementation of ESI Kit

CONSTRUCTION AND WORKING

The circuit is very sensitive and detects minute voltage variations across the

touch pads. ESI Kit comprises signal amplifier and analogue display section

along with a piezo buzzer.

The circuit diagram from ESI Kit is shown in Fig.4.Voltage variations from

the sensing touchpads (refer Fig.7) are amplified by transistor BC 548 (T1),

which is configured as common-emitter (CE) amplifier. The base of T1 is

connected to one of the touch pads through resistor R1 and to the ground

rail through potentiometer VR1.By varying VR1 the sensitivity of T1 can be

adjusted to the desired level.

Diode D1 maintains proper biasing of T1 and the capacitor C1 keeps the

voltage from emitter of T1 steady. The amplified signal from transistor T1 is

given to the input of IC LM3915 (IC1) through VR2 which form a display

system (refer Fig.8).

IC LM3915 is a monolithic integrated circuit which is used as Dot/Bar

display that senses analog voltage levels at its PIN 5 and displays them

through LEDs providing a logarithmic display. It can drive up to 10 LEDS

one by one in the dot/bar mode for each increment of 125mV in the input.

Here, we have used only 5 LEDs connected at PINS 14 through 18 of IC1.

LED 1 glows while input pin of IC1 receives 150mV, LED 5 glows when the

voltage rises to 650 mV and LED 5 flashes, a piezo buzzer PZ1 beeps when

the stress level is high. Resistors R4 and R5 and capacitor C2 form the

flashing elements. Resistor R3 maintains the LED current at around 20 mA.

Capacitor C3 should be placed closed to the PIN 3 for proper functioning of

the IC. Zener diode ZD1 is in series with resistor R6 to provide regulated 5V

to the circuit. Transparent 3mm LEDS (Green, Yellow and Red) and a small

piezo buzzer for audio visual indication are used in the circuit. Relaxed state

is indicated by the green LEDs, intermediate stress by yellow LEDs, high

level stress is indicated by red LEDs.

The circuit can be assembled as a small piece of perforated board or on a

printed circuit board (PCB). The circuit is enclosed in the plastic case with

touch pads being placed on the backside. Two self-locking straps can be

used to tie the unit around the wrist of the subject (refer Fig.7). After tying

the ESI Kit around the wrist (with touch pads) in contact with the skin VR1

is slowly varied until the LED glows (assuming subject to be in relaxed

state).VR2 is adjusted if the sensitivity of IC1 is very high. Emotional Stress

Indicator (ESI) kit is ready to be used.

APPLICATIONS

The ESI kit can be used indicate emotional stress level possessed by the

subject. Usually, humans do not feel stress in their bodies, whereas studies

say that the stress levels are not always felt by humans. The ESI Kit

measures the stress level in the form of voltage irrespective of whether or

not the subject feels the negative effects of stress, it can be used to improve

mental clarity which will have a positive effect on business, communications

and creativity. After knowing that the subject is stressed, various exercises

can be done for example breathing exercises or yoga to minimize emotional

stress. Rhythmic breathing exercises can help control your heart rate and

have a calming effect on the body, shifting attitudes and emotions. ESI kit

can act as an adjunct to other stress management practices. The stress is

expected to diminish subject’s feelings of well-being, balance and enhanced

energy will increase.

RESULT

This project’s goal is to design an Emotional Stress Indicator (ESI) kit that

allows you access your emotional pain. This project is very challenging and

it requires a large amount of research and acquainting ourselves with the

subject. We will give our full efforts to make this mini project a successful

biomedical device.

FUTURE WORK

Several improvements to this prototype ESI Kit are expected. This includes

addition of a voice recording and playback device. This can be included

instead of a piezo buzzer used in the circuit. The playback device can give

various instructions to reduce stress of the subject, initially recorded by a

medical professional. Playback voice can also include simple breathe in and

breathe out exercises such that the stress level of the subject diminished.

Additionally, an ergonomic design along with efforts can be put to minimize

the overall used up space by the perforated board, such that the subject can

easily wear the ESI Kit on his wrist.

REFERENCES

[1] Compact Oxford English Dictionary of Current English http://www.askoxford.com/concise_oed/stress

[2] Wikipedia, the free encyclopedia

http://en.wikipedia.org/wiki/Stress_(biology)

[3] The Associated Chambers of Commerce and Industry of India (ASSOCHAM) http://www.assocham.org/prels/printnews.php?id=1049

[4] The Times of India, 8 March 2003

http://timesofindia.indiatimes.com/biz/india-business/India-Inc-suffers-stress-syndrome/articleshow/39698287.cms

[5] Burren Yoga

http://www.burrenyoga.com/retreats-holidays/how-we-can-scientifically-measure-stress.html

[6] CNET News blog : Measuring stress with spit http://asia.cnet.com/crave/category/lifestyle/2005/12/

[7] emWave Personal Stress Reliever

http://www.myemwave.org/

[8] Stress Indicator by VoicePrism™

http://www.stressindicator.com/

[9] LM3915 Dot/Bar Display Driver Datasheet

www.national.com/ds/LM/LM 3915 .pdf