AUTOMATED CARDIOPULMONARY RESUSCITATION DEVICE

PROJECT

Submitted in partial fulfillment of the requirements

For the degree of

BACHELOR OF ENGINEERING

By

MERYL MICHAEL RODRIGUES

RISHABH MANOJ SHETTY

ASHISH DILIP VASWANI

Under the guidance of

Prof (Dr.) Mita Bhowmick

Professor & Head of Biomedical Dept, Thadomal Shahni Engg College, Bandra (West)

DEPARTMENT OF BIOMEDICAL ENGINEERINGTHADOMAL SHAHANI ENGINEERING COLLEGE

UNIVERSITY OF MUMBAI 2010-2011

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TABLE OF CONTENTS

Page

1. INTRODUCTION .........................................................................................1

2. REVIEW OF LITERATURE

2.1 Manual CPR vs Automated CPR ............................................................2

2.2 CPR Guidelines .......................................................................................2

2.3 Life-Stat vs AutoPulse vs Lucas ……………………………………… 5

3. DESIGN

3.1 Hardware .................................................................................................9

3.1.1 Belt Design ..................................................................................... 9

3.2.2 Spring Design ................................................................................10

3.2.3 Cam Design …………………………………………………….. 10

3.2.4 Magnetic Field Design …………………………………………..11

3.2.5 Twin Motor Design …………………………………………….. 12

3.2.6 Final Design ………………………………………………….… 13

4. IMPLEMENTATION AND TESTING

4.1 Stage I ………………………………………………………………...14

4.2 Stage II ……………………………………………………………….14

4.2.1 Materials to be Used ……………………………………………14

4.2.2 Stages in Fabrication of the Device ……………………………15

4.2.3 Mounting on the Base Plate …………………………………….15

4.2.4 Patient Plate and Adjustable Stand ……………………………...17

4.2.5 Final Mounting ………………………………………………..…17

4.2.6 Timing the Compressions …………………………………..……18

4.2.7 L293D Motor Driver………………………………………….….20

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5. CONCLUSION …………………………………………………………22

6. FURTHER SCOPE ………………………………………………………23

7. REFERENCES ………………………………………………………….24

SUMMARY

APPENDICES

Appendix I: IC 555 Multivibrator

Appendix II: L293D Motor Driver

ACKNOWLEDGMENTS

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LIST OF FIGURES

Figure Title Page

Number Number

Fig 3.1: Illustration of the entire system diagram 8Fig 3.2: Illustration of the belt design 9

Fig 3.3: Illustration of the Spring Design 10

Fig 3.4: Illustration of CAM Design 11

Fig 3.5: Illustration of Magnetic Field Design 12

Fig 3.6: Illustration of Twin Motor Design 13

Fig 3.7: Illustration of Final Design 14

Fig 4.1: Illustrations of Cardboard Design 15 and wooden components

Fig 4.2: Illustration of motor after mounting 18

on the base plate

Fig 4.3: Illustration of Final Fabricated Product 19

Fig 4.4: Illustration of Astable mode of operation 20

of IC 555

Fig 4.5: Illustration of pin description of L 293D 22

Fig 4.6: Illustration of Final Hardware Interfacing 22

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SUMMARY

The project aims to design and implement an automated cardiopulmonary

resuscitation (CPR) device, which could become a critical life-saving

equipment of the future. Absence of such a device in the healthcare industry

today is a major cause for critical loss of life in cases of sudden cardiac arrest

(SCA). Through this project, we wish to initiate a breakthrough revolution in

providing cardiac assistance in critical cases, leading to a drastic reduction in

loss of precious lives.

It is very possible to design a cost-effective and more portable ACPR device

using simple electronic components. We propose to employ high torque

motors for rotary to rectilinear conversion which can achieve the desired

results in a fraction of the existing market price. We have designed a prototype

of such a device to demonstrate its principle of working. This can be further

tweaked to suit the needs of the Indian Biomedical market.

The basic idea of the project is to have a localized thumping piston-like rod

above the chest of the patient. We propose the use of a suitable DC motor to

achieve this goal. Though the entire apparatus relies heavily on mechanical

components like the L-arm, circular disc, adjustable stands, etc, there is scope

to further develop electronic assembly for the same. The apparatus that we

have in place can be hooked up to various vital parameter acquisition systems

such as ECG electrodes and also provide for defibrillator and ambubag as per

standard WHO protocol.

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CHAPTER 1: INTRODUCTION

In India, general awareness of CPR techniques is limited to physicians and

paramedics. There exists a shocking lack of awareness about resuscitation

techniques in common public circles. When administered precisely, CPR can

save thousands of lives each year that are lost due to causes ranging from

physiological shocks such as asphyxiation due to drowning; to even sudden

myocardial infarction/ cardiac arrest (SCA).

It is proposed that designing a device which can administer the technique with

minimal human intervention can help reduce failure rates drastically. This is

because manual CPR, when performed even by qualified professionals does

have enough room for error. Automated CPR aims to eliminate these errors,

thereby reducing failure rates. The objective is to make the technique available

in rural areas where there is acute shortage of basic healthcare facilities. To

achieve this goal, it is intended to design an easy-to-use device that can even

be operated by a lay man.

When done manually, it is difficult to abide by WHO standards since it is a

life-saving technique and will need to be carried out with the required

specifications for as long as needed. This is very difficult to achieve manually.

Hence, the objective is to study the principle of administering

cardiopulmonary resuscitation manually, thereby extending the technique

mechanically by use of an automated apparatus that uses inexpensive

mechanisms to achieve the same.

This involves calculating the displacement, force and frequency of chest

compressions prescribed as per WHO standards. To identify target areas that

such equipment can cater to. For example, beaches, swimming pools, aircraft,

ambulances, etc. The final objective of the project is to study the practical

viability of implementing microcontroller-based timing devices to drive the

mechanism for predefined periods of time as required.

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CHAPTER 2: REVIEW OF LITERATURE

2.1 MANUAL CPR vs AUTOMATED CPR:

To understand the problems that are faced by paramedics while delivering

Manual CPR and to then compare it with the capabilities of Automated CPR,

the following table of is presented below:

WHO Standards specify the following conditions to be maintained for manual

CPR, hence our aim was to fabricate a machine which would do at the same

time circumventing the disadvantages of manual CPR.

Rate of chest compressions- at least 100 chest compressions per minute

(administered 30 compressions at a time, pause equivalent to two breaths

taken to check for resumption of pulse)

Vertical Displacement- 1.5 to 2 inches

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2.2 CPR GUIDELINES:

The normal procedure to be followed when a person encounters a real life

situation in which a victim needs to be resuscitated is described below:

a. IDENTIFICATION:

The first step of CPR is to try to arouse the victim if found unconscious. The

person simply might have fainted or maybe a asleep. Shake the person and call

them out loudly. If there is no response, only then do we proceed to theCPR

procedure.

b. FUNCTION:

Check for his/her breathing. We do this by leaning close on the victim's mouth

and nose and listening for their breathing sounds. If breathing is felt, there is

no need of rescue breathing.

c. TIME FRAME:

A call for medical help should be made before beginning CPR procedures. It is

important to get medical assistance as quickly as possible because CPR is a

tiring procedure and it cannot be done for a long time. The paramedics should

be on their way while CPR is being given, this improves the victim's chances

of survival. Even though the person is breathing, the victim could have other

medical problems that need immediate attention.

d. FEATURES:

The head has to be rightly positioned before the rescue breathing. This is done

by tilting the head by lifting the chin. Pinch the nose and give the person two

quick breaths. For each breath make sure that the chest is rising and falling,

this signifies that the airway is clear and the air is reaching the lungs. If not

then reposition the head and try again. If the chest still does not inflate due to

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the air, clear the airway before going ahead. This is done with the Heimlich

maneuver, once the airway is cleared, repeat the two rescue breaths and

continue with the CPR.

e. POTENTIAL:

Check for pulse and breathing. After the two breaths, check for the breathing

as you did before. Also place two fingers on the pulse point on the side of the

neck below the ear and just above the collar bone. If the victim is breathing

then it means that the heart is beating as well. Monitor the patients until the

paramedics arrive. If there is a pulse, but no breathing then continue the rescue

breathing until the victim begins to breathe or till the paramedics arrive to take

over. If there is no pulse and no breathing continue CPR until help arrives.

f. CONSIDERATIONS:

Measure the width of two fingers above the bottom of the breastbone. Place

the palm of your hand against the breastbone so the side of the hand is above

the fingers. Cover the first hand with you other hand and interlace your

fingers. With your elbows locked, give 30 chest compressions. The downward

force should be enough to depress the breastbone approximately 2 inches.

g. PREVENTION/SOLUTION:

Give two more breaths as described before. The process id breaths and chest

compressions should be repeated until help arrives or until the victim starts

breathing on his own

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2.3 LIFE-STAT vs AUTOPULSE vs LUCAS:

Before conceiving a new and efficient design, it was important to review the

existing products in the market. Here is a comparison between the three

available products currently in use in the US market:

The Zoll Autopulse uses an inflatable belt that autonomously surrounds the

chest. This belt compresses the entire thoracic area. Due to this, cases of rib

fracture have been reported in patients who have been administered automated

chest compressions using this device.

Michigan Instruments’ Lifestat is a device that administers localized

compression only on the desired region. However, the piston-like action of the

Lifestat is triggered using a pneumatic cylinder which is heavy. Due to this, it

scores low on the portability count.

Another competing product is the Lucas, which is similar in principle to the

Lifestat. Oral resuscitation is also taken care of in this model. The common

shortcoming associated with all the three devices is their high cost. Average

cost of existing models is around Rs. 12 lakh.

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From the above comparative study it could be inferred that the approach

followed by Michigan Instruments would be the one we would use to

implement the project. The reasons for selecting this product as the one to

model the project on, are reinstated from the table above.

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CHAPTER 3: DESIGN

The block diagram below illustrates the flow of the project with the various

Electronic and Mechanical components used and their functional description:

Fig 3.1: Illustration of the entire system diagram

Power Supply

In the current prototype, an AC to DC alternator is being used to get power

from mains and drive the DC motor. In the final product, a DC battery can be

used. This battery could be lithium ion or lead acid type, depending on

feasibility and cost considerations.

Electronic control

Currently, IC 555 is being used as a timer to adhere to the compression criteria

mentioned by the World Health Organization. In the future, more specialized

microcontrollers and timing devices can be used to replace it.

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Mechanical elements

The base plate, disc, rod and the L-arm form the basic building blocks of the

device. These are explained in the subsequent chapters

3.1 HARDWARE:

Before zeroing in on any one design for our project, we analyzed various

options before short listing one that fulfilled all requirements satisfactorily,

while also being practically feasible.

3.1.1 BELT DESIGN:

This design involves the use of a lower unit that is slid under the patient. An

upper unit is fit with a toothed gear motor and two gear tracks- surrounding

the gear from above and below respectively. These two tracks are secured to

the lower unit with the help of hooks. When the gear moves anticlockwise, the

tracks advance in opposite directions linearly. Because of this, the upper unit

compresses the patient’s chest. When the motor rotates in the clockwise

direction, it returns to its original elevated position. This process is repeated

continually to achieve sustained compressions.

Fig 3.2: Illustration of the belt design

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A major drawback of this design is the point of application is not localized to

the heart. It is bulky and involves the implementation of a gear that moves

electronically in one direction, as well as mechanically in the other. This

forced us to look for other designs to implement our idea.

3.1.2 SPRING DESIGN

Our second design consideration consisted of a motor around whose axle, a

high tension cord is wound. This cord passes through a tensile spring and an

applicator cushion is attached at its end. A narrow opening in the base on

which the motor rests, restricts the compression of the spring beyond a

particular limit. When the motor rotates in the anticlockwise direction, the

spring compresses by about 2 inches. This raises the applicator cushion just

above the patient’s chest. When the motor is switched off, the spring expands

freely in the absence of a puling force from the motor, which causes the

applicator cushion to compress the patient’s chest.

Fig 3.3: Illustration of the Spring Design

Finding a suitable spring that matches the requirements of stipulated Young’s

modulus and rigidity was a major hurdle in this design and was more of a trial

and error exercise than a calculated inference. Wear and tear of the spring

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could reduce the life of the spring and in course of time, the response of the

spring to the load would considerably vary than what is expected.

3.1.3 CAM DESIGN

The third design involves the use of a cam which has a groove of a suitable

depth to facilitate a displacement of 2 inches as previously mentioned. A rod

suspended vertically at the apex of the spring (or any mechanically

compressible element) would move about its fulcrum to give us the required

linear motion. At the other end of the rod, the applicator cushion would be

attached. According to the position of the fulcrum, the displacement could be

magnified. The number of grooves could be increased to provide us with an

increased number of compressions.

Fig 3.4: Illustration of CAM Design

Again, the use of a spring poses a hurdle to the life span of the apparatus.

3.1.4 MAGNETIC FIELD DESIGN

A few design options using magnets surrounded by intermittent magnetic

fields that drive the compression rod were also considered. One of the ideas

involved the use of two magnetic fields that are two inches apart from each

other. These two fields are switched on alternately. When the upper field is

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switched on, the rod is pulled up and when it is switched off, the lower

magnetic field pulls it down. The upper magnetic field could be replaced by a

spring to pull the rod up. A motor rotating in the anticlockwise direction could

also be used for the same.

Another design makes use of two ferromagnetic elements, one forming the

core of an induced magnetic field formed by a conducting wire wound around

it. By using Faraday’s Law of Electromagnetic Induction, an AC supply when

passed through the conducting wire would magnetize the core and this would

attract the other ferromagnetic block whose other end would be connected to

the applicator cushion i.e. when the field is produced the cushion is pulled up

and when it is switched off, the cushion compresses the chest.

Fig 3.5: Illustration of Magnetic Field Design

A major disadvantage of this system is the fall of the rod that is controlled

only by the lower magnetic field. To produce an effective weight 11 kg, a very

heavy rod would have to be used which could harm the patient. Switching

magnetic fields on and off is easier said than done. The magnetic core takes a

considerable amount of time to get magnetized after current is supplied to the

coil. This design was theoretically appealing but practically challenging.

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3.1.5 TWIN MOTOR DESIGN

The final design that could be implemented is using two rotating discs driven

by two motors. These two discs could either be cams or could 0have

projections on them. There would be a rod in between the two discs which

would have projections on it. The two motors should move in opposite

directions. The distance between the projections/grooves should be such that

the required displacement is achieved.

When one motor propels the rod in the forward direction, after the maximum

displacement, the other motor will pull it back to its original position. As a

result of this, by suspending this apparatus vertically, using an element to

prevent free fall of the rod, the required compressions can be obtained.

Fig 3.6: Illustration of Twin Motor Design

The drawback of this design is that two motors are used and that would

increase expenses and mechanical liability.

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3.1.6 FINAL DESIGN

After analyzing the pros and cons of each of the above ideas, we came across

the works of an American scientist, William Clark who has developed various

mechanical assemblies that convert rotational motion to rectilinear motion.

One of these completely suited our needs of achieving vertical displacement

driven by a motor that is controlled electronically.

A rod is provided with a projection at one end and a restrictor block at the

other. A disc is fit with two diametrically opposite projections which drive the

vertical rod. An L-arm is placed on a pivot that moves in tandem with the

projections on the disc. This motion can be better explained with the diagram

below:

Fig 3.7: Illustration of Final Design

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CHAPTER 4: IMPLEMENTATION AND TESTING

4.1 STAGE I:

For the first stage of the project, after finalizing the design, outlines of the

various components on paper cut-outs and card board were traced to measure

the vertical displacement that can be achieved using various dimensions of the

disc, the rod, the L-arm and the positions of the projections. When a vertical

displacement of around 2 inches was achieved, we implemented components

of the same dimensions on a wooden board to replicate the working of a life-

size model of the intended mechanical equipment.

Fig 4.1: Illustrations of the initial Cardboard Design and the subsequent Fabrication using wooden components

4.2 STAGE II:

4.2.1 MATERIALS TO BE USED:

To fabricate a sturdy and reliable device which would be capable of

delivering all the above mentioned specifications and at the same time be able

to support all the mechanical elements that we had in mind (motor, L-arm,

disc, applicator rod), we needed to use the proper kind of material.

Hence, Aluminium and Stainless Steel were opted for owing to their

inherent strength, ease of availability and economic viability.

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4.2.2 STAGES IN FABRICATION OF THE DEVICE:

Base for mounting- We first started by sawing off a plate of

aluminium which would support all the necessary components to be mounted.

We smoothened the edges of the plate by using a grinder and filer to give it

rounded edges. The plate was then polished by using a buffing machine.We

then outlined the dimensions of the various components with a marker and

started preparing those components thereafter.

Rotating Disc- We first began by sawing off a square piece and then

filing it to get an appropriate circular shape. We also used a grinder to lessen

the amount of manual labour that would go into making a perfect circular disc.

Applicator rod and L-arm- These two components were cut out of a

single metal piece and then filing and buffing them to get the appropriate

shapes and dimensions that we needed.

4.2.3 MOUNTING ON THE BASE PLATE:

Circular Disc- Since this was the most important component of the

device which would be driven by the motor and would consequently drive the

applicator rod, we took extra care to provide it with the right kind of support,

without friction. For this, we drilled a hole at the center of the disc, on the base

plate, welded a rod onto a small circular disc (smaller than our circular disc)

through a shaft on the front side and the same way on the back side. This

meant that we had stability and at the same time, freedom of movement for the

disc.

Using nuts and bolts with washers we mounted our main circular disc onto this

assembly. We also made two readymade Teflon projections on the disc for

contact with the L-arm and Applicator rod during the actual working. The

instruments used for this purpose were the Welding Machine, Drilling

Machine, Tapping screws and the Lathe Machine.

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L-arm and Applicator Rod- In order to avoid friction, the circular

disc was mounted at a height from the base plate. Owing to this fact, we had to

elevate the L-arm and the Applicator rod accordingly. Using the meter scale

and Vernier Callipers for getting the appropriate measurements, we mounted

first the L-arm on a single plastic cube support which in turn was screwed to

the base plate using a single screw. The L-arm was screwed onto this support

which acted as a pivot for its movement.

The applicator rod needed itself to be guided so that its movement would stay

strictly linear throughout the working of the device. This was accomplished by

using the plastic cubes with appropriate grooves at strategic heights being

sawed off of them. To maintain the guide cubes in position, two screws were

used to mount them on the base plate to provide the stability that was required

of them.

Onto the plastic rod was also mounted another Teflon projection for contact

with the L-arm. A spring was also affixed, its one end on a small screw

projecting from an area at the distal end of the rod and the other end on the

distal most plastic guide cube. This would ensure that there was no free fall

when the device was being set up just before application to the patient and

otherwise.

Motor- Since we needed to mount the motor in such a way that it had

stability while operating, which required it to be solidly mounted on the base

plate with adequate support.

The second consideration was the fact that we needed to be flexible in the

sense that we wanted to allow for the replacement of the motor in case we

needed higher driving power for the applicator rod.

For the above stated reasons we decided to use a bevelled gear which would

transfer the motion of the motor axle in the horizontal plane onto the circular

disc which would rotate in a plane perpendicular to the rotating axle of the

motor. The motor was supported using a thick aluminium plate which was

then grinded at the centre to accommodate the axle of the motor. This plate

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was fixed to the base plate using screws at various points for stability. Two

triangular supports were then welded at the angle to avoid any bending that

may occur during the working.

Here we understood the use of the bending machine and also the Welding

machine.

Fig 4.2: Illustration of motor after mounting on the base plate

4.2.4 PATIENT PLATE AND ADJUSTABLE STAND:

The patient plate was again fabricated using an aluminium plate which was

sawed and filed to get blunt edges and then it was bent at an angle of 16

degrees to accommodate the feet of the stand which would be shifted into it

while setting up the device for use.

The Stand was made by using two hollow tubes which were welded onto bases

which resembled the front ends of shoes. A handle was also welded at the end

of the tube for easy handling. Springs were used to make easy adjustments

when the base plate was mounted onto the stands.

4.2.5 FINAL MOUNTING:

The Base plate with all its components safely mounted on it was now ready to

be mounted on the stand to make the device fully functional. This was

achieved by screwing to it two wing-like projections from either side. The

unscrewed ends of these projections were welded to hollow tubes which were

slightly larger in diameter than the tubes of the stand.

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This meant that the tubes could easily slide and then be tightened wherever

necessary on the stand, which lent the all-important feature of height

adjustment to our device. Again, free fall was prevented by the springs on

the stands.

By simply placing the base plate under the patient’s chest, placing the base

plate on the stands, locking in the base of the stands on the under-side of the

patient plate and tightening the base plate to maintain its position, the system

would become one piece and function as a single unit by providing the motor

with power supply.

Fig 4.3: Illustration of Final Fabricated Product

4.2.6 TIMING THE COMPRESSIONS:

For the purpose of abiding by the standards set by the WHO regarding the

time for which the compressions must be given and then paused while the

paramedic checks for the patient’s pulse, we used a simple IC 555 timer in the

astable mode so that we could control the On and Off times of the

multivibrator.

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Since IC 555 can only source a current of around 200mA, it was important for

us to use a current driver which would give the appropriate amount of current

for the motor to be driven.

Fig 4.4: Illustration of Astable mode of operation of IC 555

a. IC 555 ASTABLE MODE OPERATION:

If we rearrange the circuit slightly so that both the trigger and threshhold

inputs are controlled by the capacitor voltage, we can cause the 555 to trigger

itself repeatedly. In this case, we need two resistors in the capacitor charging

path so that one of them can also be in the capacitor discharge path.

In this mode, the initial pulse when power is first applied is a bit longer

than the others, having a duration of 1.1(Ra + Rb)C. However, from then

on, the capacitor alternately charges and discharges between the two

comparator threshold voltages. When charging, C starts at (1/3)VCC and

charges towards VCC. However, it is interrupted exactly halfway there, at

(2/3)VCC. Therefore, the charging time, t1, is -ln(1/2)

(Ra + Rb)C = 0.693(Ra + Rb)C.

When the capacitor voltage reaches (2/3)VCC, the discharge transistor is

enabled (pin 7), and this point in the circuit becomes grounded. Capacitor

C now discharges through Rb alone. Starting at (2/3)VCC, it discharges

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towards ground, but again is interrupted halfway there, at (1/3)VCC. The

discharge time, t2, then, is -ln(1/2)(Rb)C = 0.693(Rb)C

The total period of the pulse train is t1 + t2, or 0.693(Ra + 2Rb)C.

b. Calculations Used:

Ra=200kΩ; Rb=50kΩ; C=100µF

Hence, Ton=0.693(Ra+Rb)C = 17.325 sec

Toff=0.693RbC=3.465 sec

4.2.7 L293D MOTOR DRIVER:

The IC 555 is not capable of sourcing enough current to drive the motor. We

needed a current source in order to drive the motor. This current source

should be able to take in logic command from the IC, then boost current and

drive the motor accordingly. We had to select the IC for motor driving as per

the requirement of current of motor.

The L293D is a monolithic integrated high voltage, high current four-channel

driver designed to accept standard DTL or TTL logic levels. It is designed to

drive inductive loads such as relay solenoids, DC/stepper motors and

switching power transistors. The L293D’s ability to handle the load of my DC

motor makes it an ideal IC for driving our main motor.

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Fig 4.5: Illustration of pin description of L 293D

As can be seen in the circuit, three pins are needed for interfacing a DC motor

(A, B, Enable). If you want the o/p to be enabled completely then you can

connect Enable to VCC and only 2 pins needed from controller to make the

motor work.

600mA output current capability per channel with1.2A peak output current.

Fig 4.6: Illustration of Final Hardware Interfacing

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5. CONCLUSION

The objective of the project was to achieve a product which would be

economically viable so that the general population could use it; at the same

time an important consideration to be kept in mind was to achieve a

displacement and timing of compressions as close to WHO standards as

possible.

The approach selected to achieve automated chest compressions was

fabricated using aluminium, stainless steel and inexpensive hardware. The

project was successfully implemented so that it could circumvent the problems

faced while administering Manual CPR and also be easy to use with a minimal

amount of training. Any mechanical changes that need to be made are easily

achievable owing to the fact that the mounting of all the components on the

base plate is done keeping that very idea in mind.

With access to better hardware and raw materials, a marketable product can be

designed in the future. The mouth-to-mouth resuscitation part of CPR can be

looked into to make this design robust and worthy of competing with the

Michigan Instruments’ LifeStat.

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6. FURTHER SCOPE

Using more versatile materials such as titanium, hard PVC and other plastic in

place of aluminium may be beneficial to add rigidity and stability to the

design. Materials that can make the product light-weight should be probed

into.

Research could be initiated in this direction to look for alternate materials that

could be used to design the skeleton of the device. With the help of

paramedical staff, an efficient mouth-to-mouth resuscitator can be added as an

accessory to make the product a suitable replacement for manual CPR.

The stand can be calibrated so that it becomes easier for the attendant

paramedical staff to adjust the stand to suit the patient’s physical

characteristics.

Another area that can be worked on is the software part, wherein, a

microcontroller can be used to drive the motor instead of the IC 555 which is

being employed currently. This would have the advantage of making the

system dynamic by interfacing the microcontroller to an LCD interface and

allowing the paramedical staff to tweak the number of compressions being

given.

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7. REFERNCES

1. Christophe A. Wyssa; Julia Foxb, Fabian Franzecka; Marco Moccettia; Alfons Scherrerc; Jens P. Hellermannd; Thomas F. Lüschera; Mechanical versus manual chest compression during CPR in a cardiac catherisation setting, Cardiovascular Medicine 2010;13(3):92–96(http://www.cardiovascular-medicine.ch/pdf/2010/2010-03/2010-03-005.PDF)

2. http://www.jolife.se/en/clinical_background/sudden_cardiac_arrest

3. Ochoa FJ ; Ramalle-Gómara E; Lisa V; Saralegui I, The effect of rescuer fatigue on the quality of chest compressions, Resuscitation. 1998 Jun; 37(3):149-52. (http://www.ncbi.nlm.nih.gov/pubmed/9715774?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum)

4. Hightower D ; Thomas SH; Stone CK; Dunn K; March JA, Decay in quality of closed-chest compressions over time, Annals of Emergency Medicine, 1995 Sep;26(3):300-3. (http://www.ncbi.nlm.nih.gov/pubmed/7661418?ordinalpos=1&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum)

5. Aufderheide TP ; Pirrallo RG; Yannopoulos D; Klein JP von Briesen C; Sparks CW; Deja KA; Kitscha DJ; Provo TA; Lurie KG, Incomplete chest wall decompression: a clinical evaluation of CPR performance by trained laypersons and an assessment of alternative manual chest compression-decompression techniques. Resuscitation, 2006 Dec;71(3):341-51. Epub 2006 Oct 27. (http://www.ncbi.nlm.nih.gov/pubmed/17070644?ordinalpos=5&itool=EntrezSystem2.PEntrez.Pubmed.Pubmed_ResultsPanel.Pubmed_RVDocSum)

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APPENDIX I: IC 555 MULTIVIBRATOR

35

36

37

38

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APPENDIX II : L293 D MOTOR DRIVER

CONSTRUCTION:

40

BREADBOARD USE:

41

PERFORMANCE CHARACTERISTICS:

42

SCHEMATICS:

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ACKNOWLEDGEMETS

We take this opportunity to express our gratitude towards our guide Prof. (Dr.)

Mita Bhowmick, Head of the Department of Biomedical Engineering,

Thadomal Shahani Engineering College, Mumbai for her constant

encouragement and guidance.

We would also like to thank Mr. Praveen Valsalan. We are grateful for his

innovative ideas, eager participation in helping us fabricate the design and for

allowing us to use his workshop for the duration of this entire endeavor.

We would like to thank Mr. Tanvir Daphedar, Lecturer, Biomedical

Engineering Department, Thadomal Shahani Engineering College for

constantly providing us with vital and ingenious ideas for the implementation

of our plans.

Meryl Michael Rodrigues

Rishabh Manoj Shetty

Ashish Dilip Vaswani

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