report on replacement of heart bypass surgery by nanorobots

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Replacement of Bypass Surgery by Nanorobots 1. INTRODUCTION The heart bypass surgery reroutes the blood supply around clogged arteries to improve blood flow and oxygen to the heart. The arteries that bring blood to the heart muscle (coronary arteries) become clogged by plaque (a buildup of fat, cholesterol and other substances). This can slow or stop blood flow through the heart's blood vessels, leading to chest pain or a heart attack. Increasing blood flow to the heart muscle can relieve chest pain and reduce the risk of heart attack. So the surgeons go for this surgery by taking a segment of a healthy blood vessel from another part of the body usually from leg and make a detour around the blocked part of the coronary artery. The surgery involves an incision in the middle of the chest and separation of the breastbone and after detouring, the breastbone is joined using wire and the incision is sewed. The entire surgery can take 4-6 hours. After the surgery, the patient is taken to the Intensive Care Unit. For a few days after the surgery, the patient is connected to monitors and tubes. Patient may experience side effects such as: • Loss of appetite, constipation. • Swelling in the area from which the segment of blood vessel was removed. Department of Biomedical engineering KLE Dr.M.S.Sheshgiri College of Engineering and Technology Page 1

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A report on the use on nanomedicine and its application in field on Heart bypass surgery

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Page 1: Report on Replacement of Heart bypass surgery by NAnorobots

Replacement of Bypass Surgery by Nanorobots

1. INTRODUCTION

The heart bypass surgery reroutes the blood supply around clogged arteries to

improve blood flow and oxygen to the heart. The arteries that bring blood to the heart

muscle (coronary arteries) become clogged by plaque (a buildup of fat, cholesterol

and other substances). This can slow or stop blood flow through the heart's blood

vessels, leading to chest pain or a heart attack. Increasing blood flow to the heart

muscle can relieve chest pain and reduce the risk of heart attack. So the surgeons go

for this surgery by taking a segment of a healthy blood vessel from another part of the

body usually from leg and make a detour around the blocked part of the coronary

artery. The surgery involves an incision in the middle of the chest and separation of

the breastbone and after detouring, the breastbone is joined using wire and the

incision is sewed. The entire surgery can take 4-6 hours. After the surgery, the patient

is taken to the Intensive Care Unit. For a few days after the surgery, the patient is

connected to monitors and tubes.

Patient may experience side effects such as:

• Loss of appetite, constipation.

• Swelling in the area from which the segment of blood vessel was removed.

• Fatigue, mood swings, feelings of depression, difficulty in sleeping.

• Muscle pain or tightness in the shoulders and upper back.

The incision in the chest or the graft site (if the graft was from the leg or arm) can be

itchy, sore, numb, or bruised. The surgery may also lead to loss of memory and mental

clarity. To overcome all these problems that are involved in the bypass surgery, a nanorobot

is used, which can replace this techniques efficiently and effectively. This nanorobot will

remove the clot without any surgical procedure. Just a small incision is made into the femoral

artery to insert this Nanorobot, from where it is moved to the site of the plaque by the use of

its nano components that are attached to it.

Department of Biomedical engineeringKLE Dr.M.S.Sheshgiri College of Engineering and Technology Page 1

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Replacement of Bypass Surgery by Nanorobots

2. STRUCTURE OF THE HEART:

The heart is an amazing organ. It beats thousands of times each day, every day,

for the entire life. In the process, it pumps about 5 million gallons of blood through the

entire body. The human heart resembles the shape of an upside down pear. It is a

hollow muscle that pumps blood throughout the blood vessels by repeated, rhythmic

contractions. An adult human heart has a mass of between 250 and 350 grams and is

about the size of a fist. It is located anterior to the vertebral column and posterior to the

sternum. The heart is enclosed in a double-walled sac called the pericardium. It has

two leaflets, the superficial is called the parietal pericardium and the inner one is the

visceral pericardium. The outer wall of the human heart is composed of three layers.

The outer layer is called the epicardium, or visceral pericardium since it is also the

inner wall of the pericardium. The middle layer is called the myocardium and is

composed of cardiac muscle which contracts. The inner layer is called

the endocardium and is in contact with the blood that the heart pumps. The human

heart has four chambers, two superior atria and two inferior ventricles. The atria are

the receiving chambers and the ventricles are the discharging chambers.

Department of Biomedical engineeringKLE Dr.M.S.Sheshgiri College of Engineering and Technology Page 2

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Replacement of Bypass surgery by Nanorobots

2.1. BLOOD FLOW IN HEART:

The heart is a complex organ, using four chambers, four valves and multiple blood

vessels to provide blood to the body. The flow through the heart is equally complex, with

blood moving through the heart, then the lungs, before returning again to the heart.

Blood returns to the heart from the body via two large blood vessels, called the superior

vena cava and the inferior vena cava. This blood carries little oxygen, as it is returning

from the body where oxygen is used.

Fig. Circulation of Blood flow in Heart

Department of Biomedical engineeringKLE Dr.M.S.Sheshgiri College of Engineering and Technology Page 3

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The blood first enters the right atrium. It then flows through the tricuspid valve

into the right ventricle. When the heart beats, the ventricle pushes the blood through the

pulmonic valve into the pulmonic artery. This artery is unique. It is the only artery in the

human body that carries oxygen-poor blood.

The pulmonic artery carries blood to the lungs where it “picks up” oxygen, and

leaves the lungs and returns to the heart through the pulmonic vein. The blood enters the

left atrium, and then descends through the mitral valve into the left ventricle. The left

ventricle then pumps blood through the aortic valve, and into the aorta, the blood vessel

that leads to the rest of the body.

The valve at the top of each ventricle opens to allow it to fill, while the valve at the

bottom makes sure the blood doesn’t leak out. When the ventricle is full, the top valve

closes and the bottom valve opens. The ventricle squeezes the blood out forcefully

through the bottom valve. Essentially, the valves keep the blood flowing in the correct

direction through the heart.

Department of Biomedical engineeringKLE Dr.M.S.Sheshgiri College of Engineering and Technology Page 4

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Replacement of Bypass surgery by Nanorobots

3. BYPASS SURGERY AND ITS NEED:

Heart bypass surgery  is used to treat heart disease when the coronary arteries are

blocked. The doctor treats the problem by giving the blood a new pathway to the heart.

Hence the name Bypass surgery. There are two main coronary arteries--the right coronary

artery and the left coronary artery. The right coronary artery splits off into two more

arteries, known as the right marginal artery and the posterior descending artery. The left

coronary artery splits into two additional arteries as well--the circumflex artery and the left

anterior descending artery. This makes six total arteries in the human heart.

If one of these outer arteries gets blocked, it causes a heart attack. A blockage like this is

normally caused by fatty deposits that build up in the heart's arteries over the course of

many years. When one of the heart's arteries gets blocked and a person has a heart attack,

one common procedure is to perform heart surgery and sew in a new piece of blood vessel

to bridge over (bypass) the blockage. In many cases, the surgeon will fix not only the

immediate problem, but also other arteries on the heart that are starting to look blocked.

In some cases, the surgeon can perform this operation while your heart is still beating.

This is called "off-pump" coronary bypass surgery.

Fig. Coronary artery Bypass graft

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If the surgeon repairs three of the arteries, it is called a triple bypass. If four arteries are

repaired, it's a quadruple bypass. The blood vessel used to create the bypass is taken from

the chest or the leg as the body has several vessels that can be removed without doing

harm.

Arteriosclerosis is a common arterial disorder characterized by thickening, loss of

elasticity, and calcification of arterial walls, resulting in a decreased blood supply.

Atherosclerosis is a common arterial disorder characterized by yellowish plaques

of cholesterol, lipids, and cellular debris in the inner layer of the walls of large and

medium-sized arteries.

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4. ROUTINE PROCEDURE OF BYPASSS SURGERY:

The patient is brought to the operating room and moved on to the operating table.

An anesthetist places a variety of intravenous lines and injects a painkilling agent followed

within minutes by an induction agent to render the patient unconscious.

An endotracheal tube is inserted and secured by the anesthetist and mechanical

ventilation is started. General anesthesia is maintained by a continuous very slow

injection.

The chest is opened via a median sternotomy and the heart is examined by the surgeon.

The bypass grafts are harvested – frequent conduits are the internal thoracic arteries, radial

arteries and saphenous veins. When harvesting is done, the patient is given heparin to

prevent the blood from clotting.

In the case of "off-pump" surgery, the surgeon places devices to stabilize the heart.

If the case is "on-pump", the surgeon sutures cannulae into the heart and instructs

the perfusionist to start cardiopulmonary bypass (CPB). Once CPB is established, the

surgeon places the aortic cross-clamp across the aorta and instructs the perfusionist to

deliver cardioplegia (a special potassium-mixture, cooled) to stop the heart and slow its

metabolism. Usually the patient's machine-circulated blood is cooled to around 84

°F (29 °C)

One end of each graft is sewn on to the coronary arteries beyond the blockages and the

other end is attached to the aorta.

The heart is restarted; or in "off-pump" surgery, the stabilizing devices are removed. In

cases where the aorta is partially occluded by a C-shaped clamp, the heart is restarted and

suturing of the grafts to the aorta is done in this partially occluded section of the aorta

while the heart is beating.

Chest tubes are placed in the mediastinal and pleural space to drain blood from around the

heart and lungs.

The sternum is wired together and the incisions are sutured closed.

The patient is moved to the intensive care unit (ICU) to recover.

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Nurses in the ICU focus on recovering the patient by monitoring blood pressure, urine output

and respiratory status as the patient is monitored for bleeding through the chest tubes. If there

is a chest tube clogging, complication such as cardiac tamponade, pneumothorax or death can

ensue. Thus nurses closely monitor the chest tubes and undertake methods to prevent clogging

so bleeding can be monitored and complications can be prevented.

After awakening and stabilizing in the ICU (approximately one day), the person is

transferred to the cardiac surgery ward until ready to go home (approximately four days).

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5. NANOROBOTS:

Nanorobots are theoretical microscopic devices measured on the scale of

nanometers (1nm equals one millionth of 1 millimeter). When fully realized from the

hypothetical stage, they would work at the atomic, molecular and cellular level to perform

tasks in both the medical and industrial fields. Nanomedicine’s nanorobots are so tiny that

they can easily traverse the human body. Scientists report the exterior of a Nanorobot will

likely be constructed of carbon atoms in a diamondoid structure because of its inert

properties and strength. Super-smooth surfaces will lessen the likelihood of triggering the

body's immune system, allowing the nanorobots to go about their business unimpeded.

Glucose or natural body sugars and oxygen might be a source for propulsion and the

Nanorobot will have other biochemical or molecular parts depending on its task.

5.1. ELEMENTS OF NANOROBOT:

Carbon will likely be the principal element comprising the bulk of a medical

Nanorobot, probably in the form of diamond or diamondoid/fullerene nano composites.

Many other light elements such as hydrogen, sulphur, oxygen, nitrogen, fluorine, silicon,

etc. will be used for special purposes in nanoscale gears and other components.

Morphological examination revealed no physical damage to either fibroblasts or

macrophages, and human osteoblast like cells confirming the biochemical indication that

there was no toxicity and that no inflammatory reaction was elicited in vitro. The

smoother and more flawless the diamond surface, the lesser is the leukocyte activity and

fibrinogen adsorption.

The exterior surface with near-nanometer smoothness results in very low bioactivity. Due

to the extremely high surface energy of the passivated diamond surface and the strong

hydrophobicity of the diamond surface, the diamond exterior is almost completely

chemically inert.

Department of Biomedical engineeringKLE Dr.M.S.Sheshgiri College of Engineering and Technology Page 9

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5.2. NANOROBOTS IN MEDICAL FIELD:

Nanomedicine is the medical application of nanotechnology. The approaches towards

nanomedicine range from the medical use of nonmaterial’s, to nanoelectronic biosensors,

and even possible future applications of molecular nanotechnology. Medical nanodevices

could augment the immune system by finding and disabling unwanted bacteria and

viruses. When an invader is identified, it can be punctured, letting its contents spill out and

ending its effectiveness. If the contents were known to be hazardous by themselves, then

the immune machine could hold on to it long enough to dismantle it more completely.

5.3. NANOROBOTS IN HEART SURGERY:

Heart blockings are occurring more and more. The most common methods of surgery for

heart attacks are By-Pass surgery and Angio Plaster. But these methods are risky and bring

several side-effects with them. Surgery with nanorobots is safer and the surgeon doesn’t

even have to touch the patient. Nanorobots as a heart surgeon could replace the mentioned,

current surgeries and thus manage the same result without the side effects. The procedure

would consist of locating and serving the block. After locating the blockade, nanolasers

could be used to tackle the block after getting confirmation by the practitioners.

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6. PROPERTIES OF THE NANOROBOT USED IN BYPASS

SURGERY:

The nanorobots structure will have two spaces that will consist of an interior and exterior.

The exterior of the nanorobot will be subjected to the various chemical liquids in our

bodies but the interior of the nanorobot will be a closed, vacuum environment into which

liquids from the outside cannot enter. A nanorobot will prevent itself, from being attacked

by the immune system by having a passive, diamond exterior. The diamond exterior will

have to be smooth and flawless to prevent Leukocytes activities since the exterior is

chemically inert and have low bioactivity. An electric motor is attached to this nanorobot

for its propagation inside the circulatory system in the blood vessels. The microprocessor,

artery thermometer, camera, rotating needle are also incorporated in this nanomachine,

which perform the vital role of the nanorobot. The microprocessor controls the overall

operation of this nanorobot .The radioactive material is impregnated and is made as a part

of the exterior surface, which helps us to trace the nanorobot at any period of time. The

magnetic switch is also provided to switch on and off the nanorobot at any point of time.

Fig. Nanorobot in blood cells

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7. INTRODUCTION OF NANOROBOT IN TO THE BODY AND THE

SOURCE OF MOVING:

Nanorobot gets access into the body through a large diameter artery so that it may move

easily without being too destructive in the first place. This artery should be traversed

easily to gain access to most areas of the body in minimal time. The obvious candidate is

the femoral artery in the leg. This is in fact the normal access point to the circulatory

system for operations that require access to the bloodstream for catheters, dye injections,

etc.

Fig. Nanorobot and its structure

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The circulatory system allows the device to move about. But to get access to the site of

operation of the nanorobot, it must have active propeller. Therefore, an electric motor is

used. This electric motor will have a shrouded blade design so as to avoid damage to the

surrounding tissues (and to the propellers) during the inevitable collisions. Long-range

sensors are used to navigate to the site of the plaque closely enough so that the use of

short-range sensors is practical. These sensors would be used during actual operations, to

allow the device to distinguish between healthy and unwanted tissue. A small amount of

radioactive substance is impregnated as part of the micro robot. This would allow its

position to be tracked throughout the body at all times. After reaching the site of location

the internal sensor is used to find out the exact location of the plaque and also by using TV

camera the plaque can be more precisely located. The area where the temperature exceeds

than the maximum limit set in the nanorobot, will be operated on by the Nanorobot i.e.

that part will be cut by the rotator needle attached to the nanorobot. A TV camera in the

device helps in transmitting the picture outside the body to a remote control station,

allowing the people operating the device to steer it and also to view the internal

environment of the circulatory system.

Department of Biomedical engineeringKLE Dr.M.S.Sheshgiri College of Engineering and Technology Page 13

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8. TREATMENT OF PLAQUE AND MEANS OF REMOVAL OF

NANOROBOT:

As the nanorobot detects the site of plaque using camera and thermometer, it will activate

the rotating needle. The diamond chipped burr grinds the plaque into micro particles,

which then travel harmlessly through the circulatory system and are eventually eliminated

by the body. Cutting procedure is monitored using the camera and care is taken that it will

not cut the surrounding tissue. This care is taken by the magnetic switch that has been

provided in it. Once the nanorobot has been inserted into the body, it starts the operation

only when a bar magnet is moved over it. This movement of magnet in one direction only

makes the magnetic switch in on condition, and the nanorobot becomes active. Hence if

any problem occurs during the task of removal of plaque and shutting of the nanorobot is

the only solution, then by making the magnetic switch off by moving the bar magnet again

will terminate all the running functions of this nanomachine .After the nanorobot has

removed the plaque, and its function is over, it has to be removed from the body. This can

be made possible by guiding the Nanorobot to anchor a blood vessel that is easily

accessible from outside, and perform a small surgical operation is performed to remove it.

Fig:A sample picture of the bypass surgery

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Replacement of Bypass surgery by Nanorobots

9. SOURCE OF POWER FOR THE ROBOT:

The nuclear power is carried onboard to supply required amount of energy for the

operation of the device. This would be relatively easy to shield given the amount of fuel

involved, and it has other advantages as well. The same radioactive material could be used

for power and tracking, since the casing must be hotter than body temperature to produce

power and there would be no worries about running out of power, or insufficient power to

get the job done. At the micro scale, shielding and power conversion are relatively easy,

making this method extremely practical.

Fig:Sample image of a nanorobot inside the red blood cells.

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10. ADVANTAGES AND DISADVANTAGES

ADVANTAGES:

The nanorobots do not generate any harmful activity as they work only in specific site as

told by the physician.

Rapid elimination of diseases.

Nanorobots might also reproduce copies of themselves to replace worn out unit, a process

called self replication.

The major advantage of Nanorobot is the durability which in theory is thought be for bout

decades and centuries.

DISADVANTAGES:

The Nanorobot should be very accurate otherwise harmful events may occur.

The initial design cost is very high.

The design of this robot is very complicated.

Hard to interface, customize and design.

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CONCLUSION:

It is a proposed idea that can be made practical by the existing engineering technology.

a) The Nanorobot to be designed must be biocompatible.

b) The size of the Nanorobot should not be more than 3 micron so as, not to block any

capillary.

c) The Nanorobot should resist the corrosive environment of the blood vessels.

d) The nano particles that are attached to this Nanorobot should be held tightly and must

be durable.

With the application to healthcare, nanotechnology is indeed quite the exciting and

revolutionary technique in the pursuit of quality healthcare. Nanomedicine endeavors to

improve human health utilizing molecular tools and nano particles. The technology and

the applicability of it to the human body is still at preliminary stages 

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BIBLIOGRAPHY

Replacement Of Heart Bypass Surgery By Nanorobots, International Journal Of

Advanced Research And technology, www.ijart.org/2012/IJART080.pdf ,Shinob

M.C, Department of ECE,Roever Engineering College,Perambalur Jidhin G,

Department of ECE,Roever Engineering College,Perambalur

www.frost.com,www.frost.com/sublib/display-market-insightop.do?id=130393722

Possibilitieswithnanorobotics,3407713mcfilmer.files.wordpress.com/2012/11/

report-assignment-1.pdf

123seminarsonly,123seminarsonly.com/Seminar-Reports/039/66242411-Nano-

Robots.pdf

Discoveryhealth,health.howstuffworks.com/medicine/surgeriesprocedures/

question120.

wiseGEEK, www.wisegeek.com/what-are-nanorobots.htm

John Hopkins

medicine,www.hopkinsmedicine.org/heart_vascular_institute/clinical_services/

specialty_areas/coronary_artery_surgery.html

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