NANOROBOTS -The future nano surgeonsABSTRACT: organic substances interferes with normal bodilyLike primitive engineers faced with advanced function.technology, medicine must „catch up with the In this paper, we will describe a NanoRobottechnology level of the human body before it can that can be created with existing technology ,become really effective. Since the human body is that can be used to seek out and destroy inimicalbasically an extremely complex system of tissue within the human body that cannot beinteracting molecules (i.e., a molecular machine), accessed by other means.the technology required to truly understand and The construction and use of such devices wouldrepair the body is molecular machine technology. result in a number of benefits. Not only would itA natural consequence of this level of provide either cures or at least a means oftechnology will be the ability to analyze and controlling or reducing the effects of a number ofrepair the human body as completely and ailments, but it will also provide valuableeffectively as we can repair any conventional empirical data for the improvement and furthermachine today development of such machines. Practical data Nanotechnology is “Research and garnered from such operations at the microscopictechnology development at the atomic, molecular level will allow the elimination of a number ofand macromolecular levels in the length scale of false trails and point the way to more effectiveapproximately 1 -100 nanometer range, to methods of dealing with the problems inherent inprovide a fundamental understanding of operation at that level.phenomena and materials at the nanoscale and to We will address and propose the method ofcreate and use structures, devices and systems entry into the body, means of propulsion, meansthat have novel properties and functions because of maintaining a fixed position while operating,of their small and/or intermediate size.” control of the device, power source, means ofThis paper will describe a micro/nano scale locating substances to be eliminated, mans ofmedical robot that is within the range of current doing the elimination and how to remove theengineering technology. It is intended for the device from the body afterward.treatment and/or elimination of medical NANOMEDICNE:problems where accumulation of undesired It is the application of nanotechnology (engineering of tiny machines) to the prevention
and treatment of disease in the human bodys.More specifically, it is the use of engineerednanodevices and nanostructures to monitor,repair, construct and control the humanbiological system on a molecular level. The mostelementary of nanomedical devices will be usedin the diagnosis of illnesses. A more advanceduse of nanotechnology might involve implanted circulatory systemdevices to dispense drugs or hormones as needed be balanced against the fact that the larger thein people with chronic imbalance or deficiency nanomachine the more versatile and effective itstates. Lastly, the most advanced nanomedicine can be. This is especially important in light ofinvolves the use of Nanorobots as miniature the fact that external control problems becomesurgeons. Such machines might repair damaged much more difficult if we are trying to usecells, or get inside cells and replace or assist multiple machines, even if they dont get in eachdamaged intracellular structures. At the extreme, others way.nanomachines might replicate themselves, or The second consideration is we have to get itcorrect genetic deficiencies by altering or into the body without being too destructive in thereplacing DNA (deoxyribonucleic acid) first place. This requires that we gain access to amolecules. large diameter artery that can be traversed easily to gain access to most areasIntroduce the device into the body:We need to find a way of introducing thenanomachine into the body, and allowing itaccess to the operations site without causing toomuch ancillary damage. We have already madethe decision to gain access via the circulatorysystem.The first is that the size of the nanomachinedetermines the minimum size of the blood vessel femoral arterythat it can traverse. We want to avoid damaging of the body in minimal time. The obviousthe walls of whatever blood vessel the device is candidate is the femoral artery in the leg. This isin, we also do not want to block it much, which in fact the normal access point to the circulatorywould either cause a clot to form, or just slow or system for operations that require access to thestop the blood flow. What this means is that the bloodstream for catheters, dye injections, etc., sosmaller the nanomachine the better. However, it will suit our purposes.this must
Move the device around the body: smaller than we would need for our preliminaryWe start with a basic assumption: that we will microrobot. One or several of these motors coulduse the circulatory system to allow our device to be used to power propellers that would push (ormove about. We must then consider two pull) the microrobot through the bloodstream.possibilities: (a) carried to the site of We would want to use a shrouded blade designoperations,(b) to be propelled so as to avoid damage to the surrounding tissuesThe first possibility is to allow the device to be (and to the propellers) during the inevitablecarried to the site of operations by means of collisionsnormal blood flow. There are a number of 2.Cilia/flagellae:requirements for this method . We must be able we are using some sort of vibrating ciliato navigate the bloodstream; to be able to guidethe device so as to make use of the blood flow.This also requires that there be an uninterruptedblood flow to the site of operations. In the caseof tumors, there is very often damage to thecirculatory system that would prevent our device (similar to those of a paramecium) to propel thefrom passively navigating to the site. In the case device. A variation of this method would be toof blood clots, of course, the flow of blood is use a fin-shaped appendage. While this may havedammed and thus our device would not be its attractions at the molecular level of operation,carried to the site without the capability for 3.Crawl along surface:active movement. Another problem with this Rather than have the device float in the blood, ormethod is that it would be difficult to remain at in various fluids, the device could move alongthe site without some means of maintaining the walls of the circulatory system by means ofposition, either by means of an anchoring appendages with specially designed tips,technique, or by actively moving against the allowing for a firm grip without excessivecurrent. damage to the tissue. It must be able to do this despite surges in the flow of blood caused by the beating of the heart, and do it without tearing through a blood vessel or constantly being torn free and swept away.There are a number of means available for activepropulsion of our device.1.Propeller:An electric motor that fit within a cube 1/64th ofan inch on a side is used . This is probably along the wall of vessel
For any of these techniques to be practical, they the operations site; that is, the location of themust each meet certain requirements: clot, tumor or whatever is the unwanted tissue.The device must be able to move at a practical The second purpose is to gain a rough idea ofspeed against the flow of blood. where the microrobot is in relation to that tissue.The device must be able to move when blood is This information will be used to navigate closepooling rather than flowing steadily. enough to the operations site that short-rangeThe device must be able to move in surges, so as sensors will be usefulto be able to get through the heart without being (1).Ultrasonic:stuck, in the case of emergencies. This technique can be used in either the active orThe device must either be able to react to the passive mode. In the active mode, anchanges in blood flow rate so as to maintain ultrasonic signal is beamed into the body, andposition, or somehow anchor itself to the body so either reflected back, received on the other sideas to remain unmoving while operating. of the body, or a combination of both. TheMovement of the device : received signal is processed to obtainThe next problem to consider is exactly how to information about the material through which itdetect the problem tissue that must be treated. has passed.We need two types of sensors. Long-range In the passive mode, an ultrasonic signal of asensors will be used to allow us to navigate to very specific pattern is generated by thethe site of the unwanted tissue. We must be able microrobot. By means of signal processingto locate a tumor, blood clot or deposit of arterial techniques, this signal can be tracked with greatplaque closely enough so that the use of short- accuracy through the body, giving the preciserange sensors is practical. These would be used location of the microrobot at any time. Theduring actual operations, to allow the device to signal can either be continuous or pulsed to savedistinguish between healthy and power, with the pulse rate increasing or being switched to continuous if necessary for more detailed position information. (2).NMR/MRI: This technique involves the application of a powerful magnetic field to the body, and subsequent analysis of the way in which atomsunwanted tissue.. Another important use for within the body react to the field.sensors is to be able to locate the position of themicrorobot in the body. First we will examinethe various possibilities for external sensors.These will be at least partially external to themicrorobot, and their major purpose will betwofold. The first is to determine the location of MRI
It usually requires a prolonged period to obtain and analyze the results of its operations. Theseuseful results, often several hours, and thus is not sensors will be of two types. The first type willsuited to real-time applications. While the be used to do the final navigation. When theperformance can be increased greatly, the device is within a short distance of the operationresolution is inherently low due to the difficulty site, these sensors will be used to help it find theof switching large magnetic fields quickly, and rest of the path, beyond what the external sensorsthus, while it may be suited in some cases to the can do. The second type of sensor will be usedoriginal diagnosis, it is of only very limited use during the actual operation, to guide theto us at present. microrobot to the tissue that should be removed(3).X-ray: and away from tissue that should not beX-rays as a technique have their good points and removed.bad points. On the plus side, they are powerful (1).Chemical:enough to be able to pass through tissue, and Chemical sensors can be used to detect traceshow density changes in that tissue. This makes chemicals in the bloodstream and use the relativethem very useful for locating cracks and breaks concentrations of those chemicals to determinein hard, dense tissue such as bones and teeth. On the path to take to reach the unwanted tissue.the other hand, they go through soft tissue so This would require several sensors so as to bemuch able to establish a chemical gradient, the alternative would be to try every path, and retrace a path when the blood chemicals diminish. While it is not difficult to create a solid-state sensor for a given chemical, the difficulty increases greatly when the number of chemicals that must be analyzed increases. Consequently, we would probably need a series mobile Xraymore easily that an X-ray scan designed to show of microrobots, one for each chemical, or at leastbreaks in bone goes right through soft tissue a set of replaceable sensor moduleswithout showing much detail. On the other hand, (2).Spectroscopic:a scan designed for soft tissue can‟t get through This would involve taking continuous smallif there is any bone blocking the path of the x- samples of the surrounding tissue and analyzingrays. them for the appropriate chemicals. This could be done either with a high-powered laser diodeControl the device: or by means of an electrical arc to vaporize smallwe consider the case of internal sensors. When amounts of tissue. The laser diode is morewe say internal sensors, we mean sensors that are practical due to the difficulty of striking an arc inan integral part of the microrobot and are used by a liquid medium and also due to the side effectsit to make the final approach to the operation site possible when sampling near nerve tissue. The
diode could be pulsed at regular intervals, with away, to be eliminated by the normalan internal capacitor charging constantly so as to mechanisms of the body.provide more power to the laser diode than the In the case of blood clots, it is possible that thesteady output of our power source. action of physically attacking the clot could(3).TV camera: cause it to break away in large chunks, some ofThis method involves us having a TV camera in which could subsequently cause blockages in thethe device and transmitting its picture outside the blood flow.. We can set up some mechanism tobody to a remote control station, allowing the catch these blood clots and further break thempeople operating the device to steer it. One up,disadvantage of this technique is the relatively In the case of tumors, the problem is morehigh complexity of the sensors. On the other serious. The act of physically shredding or evenhand, solid-state television sensors are an just breaking loose clumps of cells can result inextremely well developed technology, and it the cancer metastasizing throughout the body.should not be difficult to further develop it to the One possible solution is to filter the cancerouslevel needed. This could be combined with the cells out of the blood immediately downstreamlaser diode at low power of the tumor. Even if it is possible to distinguishMeans of treatment: cancerous cells from normal cells by filtering,The treatment for each of the medical problems this would not prevent the spread of tumoris the same in general; we must remove the causing chemicals released by the ruptured cells.tissue or substance from the body. This can be (2).Physical trauma:done in one of several ways. We can break up Another way of dealing with the unwantedthe clump of substance and rely on the body‟s tissues is by destroying them in situ. This wouldnormal processes to eliminate it. Alternately, we avoid damaging the cancerous cells and releasingcan destroy the substance before allowing the chemicals into the bloodstream. In order to dobody to eliminate the results. We can use the this effectively, we need a means of destroyingmicrorobot to physically remove the unwanted the cell without rupturing the cell wall until aftertissue. We can also use the microrobot to it is safe. We shall consider a number of methodsenhance other efforts being performed, and (a)Resonant microwaves/Ultrasonics:increase their effectiveness. Rather than merely apply microwave/infrared or(1).Physical removal: ultrasonic energy at random frequencies, theThis method can be effective in the treatment of frequency of the energy could be applied at thearteriosclerosis. In this case, a blade, probe or specific frequencies needed to disrupt specificedge of some sort can be used to physically chemical bonds. This would allow us to makeseparate deposits of plaque from the artery walls. sure that the tumor producing chemicals createdThe bloodstream would carry these deposits by cancerous cells would be largely destroyed, with the remaining amounts, if any, disposed of by the body‟s natural defenses.
(b)Heat: In this case, the power would be transmitted toThe use of heat to destroy cancerous tumors the microrobot from outside the body. This canwould seem to be a reasonable approach to take. be done in a number of different ways, but itThere are a number of ways in which we can boils down to two possibilities. The first is toapply heat, each with advantages and transmit the power by means of a physicaldisadvantages of their own. While the general connection, and the second, of course, is totechnique is to apply relatively low levels of heat transmit it without a physical connection.for prolonged periods of time, we can apply (a)Physical connectionmuch higher levels for shorter periods of time to In the first case, we would need some sort ofget the same effect. wire or cable to carry power between the( c )Microwave: microrobot and the outside power source.Microwave radiation is directed at the cancerous Problems faced are the first, of course, is that thecells, raising their temperature for a period of wire needs to be able to reach inside the body totime, causing the death of the cells in question. where the microrobot is. This means that it mustThis is normally done by raising the temperature be thin enough to fit down every blood vesselof the cells to just enough above body that the microrobot can enter.temperature to kill them after many minutes of (b)No physical connection:exposure. we are transmitting power to the microrobot(d)Ultrasonic: without the use of wires or any sort of physicalAn ultrasonic signal, which can be generated by means to transfer the power.a piezoelectric membrane or any other rapidly 1.Ultrasonicvibrating object, is directed at, and absorbed by, 2.Induced magneticthe cells being treated. This energy is convertedto heat, raising the temperature of the cells and Means of recovery from the body:killing.(e)Power from the bloodstream: Given sufficiently accurate control of theThere are three possibilities for this scenario. In nanomachine, or a tether, this is not a problem;the first case, the microrobot would have we can just retrace our path upstream. However,electrodes mounted on its outer casing that it would be a lot easier, and recommended, towould combine with the electrolytes in the blood steer a path through the body that traverses majorto form a battery. This would result in a low blood vessels and winds up at a point where wevoltage, but it would last until the electrodes can just filter the nanomachine out of thewere used up. The disadvantage of this method is bloodstream. This will reduce the possibilitiesthat in the case of a clot or arteriosclerosis, there for difficulties, and also cause less wear and tearmight not be enough blood flow to sustain the on the nanomachine. Of course, either scenario isrequired a possibility, depending on where the actualPower to NanoRobot: operation site is. Another possibility is to have
the nanomachine anchor itself to a blood vessel artery walls. This will allow for both improvingthat is easily accessible from outside, and the flexibility of the walls of the arteries andperform a small surgical operation to remove it. improving the blood flow through them. In viewApplication of nanorobots : of the years it takes to accumulate these deposits,1.Tumors. simply removing them from the artery walls and leaving them in the bloodstream should allow the We must be able to treat tumors; that is to say, body‟s natural processes to remove the cells grouped in a clumped mass. While the overwhelming preponderance of material.technique may eventually be used to treat small 3.Blood clots: The cause damage when they travel to the bloodstream to a point where they can block the flow of blood to a vital area of the body. Thisnumbers of cells in can result in damage to vital organs in very short order. In many if not most cases, these lung tumorthe bloodstream,,. The specified goal is to beable to destroy tumorous tissue in such a way asto minimize the risk of causing or allowing arecurrence of the growth in the body. Thetechnique is intended to be able to treat tumorsthat cannot be accessed via conventional surgery,such as deep brain tumors.2.Arteriosclerosis: Blood clot blood clots are only detected when they cause aThis is caused by fatty deposits on the walls of blockage and damage the organ in question,arteries. The device should be able to remove often but not always the brain. By using athese deposits from the microrobot in the body to break up such clots into smaller pieces before they have a chance to break free and move on their own 4.Kidney stones Arteriosclerosis
break up the liver stones as well. By continuing on up the bile duct into the liver, they can clear away accumulated deposits of unwanted minerals and other substances as well. 6.Burn and wound debriding:By introducing a microrobot into the urethra in a The microrobots can also be used to cleanmanner similar to that of inserting a catheter, wounds and burns. Their size allows them to bedirect access to the kidney stones can be very useful for removing dirt and foreignobtained, and they can be broken up directly. particles from incised and punctured wounds, asThis can be done either by means of ultrasonics well as from burns. They can be used to do adirectly applied, or by the use of a laser or other more complete and less traumatic job thanmeans of applying intense local heat to cause the conventional techniques.stones to break up. 7.Remove or break down tar, etc in lungs: They could be very useful for the treatment of dirty lungs. This could be done by removing particles of tar and other pollutants from the surface of the alveoli, and placing them where the natural processes of the body can dispose of kidney stones them. This would require a microrobot capable of moving within the lungs, on alveolar surfaces5.Liver stonesLiver stones accumulate in the bile duct.Microrobots of the above type can be introducedinto the bile duct and used to as well as Break down of tar over the mucus layer and over the cilia within the lungs. Stones Inside Liver Bile Ducts THE ADVANTAGES OF NANOMEDICINE:
1.Speed of Medical Treatment: Doctors may describing exactly what was found, and whatbe surprised by the incredible quickness of was done, and what problems were encountered,nanorobotic action when compared to the speeds in every cell visitedavailable from fibroblasts or leukocytes.Biological cilia beat at ~30 Hz while mechanical 6. Minimum Side Effects: Mechanicalnanocilia may cycle up to ~20 MHz, though nanorobots may be targeted with virtually 100%practical power restrictions and other accuracy to specific organs, tissues, or evenconsiderations may limit them to the ~10 KHz individual cellular addresses within the humanrange for most of the time. body . Such nanorobots should have few if any side effects, and will remain safe even in large2. Non-degradation of Treatment Agents: dosages because their actions can be digitally self-regulated using rigorous control protocols.Diagnostic and therapeutic agents constructed ofbiomaterials generally are biodegradable in vivo. CONCLUSION:However, suitably designed nanorobotic agents Nanomedicine will eliminate virtually allconstructed of nonbiological materials are not common diseases of the 20th century, virtuallybiodegradable. all medical pain and suffering, and allow the extension of human capabilities most especially3.Control of Nanomedical Treatment: A our mental abilities.digital biocomputer, which is possible in theory, A nanostructured data storage device about thehas slower clock cycles, less capacious memory size of a human liver cell implanted in the brainper unit volume, and longer data access time and could store a large amount of data and providespoorer control extremely rapid access to this information. But perhaps the most important long-term benefit to4.Faster and More Precise Diagnosis: The human society as a whole could be the dawninganalytic function of medical diagnosis requires of a new era of peace. We could hope that peoplerapid communication between the injected who are independently well fed, well-clothed,devices and the attending physician. well-housed, smart, well educated, healthy andNanomachines, with their more diverse set of happy will have little motivation to make war.input-output mechanisms, can out message the Human beings who have a reasonable prospectresults of in vivo reconnaissance or testing of living many "normal" lifetimes will learnliterally in seconds patience from experience, and will be extremely5. Verification of Progress and Treatment: unlikely to risk those "many lifetimes" for anyUsing a variety of communication modalities, but the most compelling of reasons.nanorobots can report back to the attending Finally, and perhaps mostphysician, with digital precision, a summary of importantly, no actual working nanorobot has yetdiagnostically- or therapeutically-relevant data been built. Many theoretical designs have been
proposed that look good on paper, but thesepreliminary designs could change significantlyafter the necessary research, development andtesting has been completed.