Abstract:
Robots are developed for various purposes. Some robots are created for the entertainment and some robots are created for doing some small jobs. The research area concentrates more on the development of medical nanorobots, which will make the medical treatment more efficient and easy. Nanorobot is composed of many nano devices. It has nano biosensors inside it which will help to diagnose the particular disease .There are many applications of this medical nanorobots. It can be used in the treatment of cancer, brain aneurysm and diabetes.
1.Introduction:
In the present scenario there is a vast improvement and growth in information technology, nanoelectronics and biochemistry. This leads to the development of nanorobots. Medical nanorobots should consist of integrated devices which are responsible for sensing, actuation, remote control uploading, energy supply and transmission of data. The main tools in the development of nanotechnology are three dimensional prototyping and simulation. VLSI chips can be developed quickly with the use of these tools.
Organic and inorganic are the two methods of fabricating nanorobots (Cavalcanti, 2007). Organic method uses ATP and DNA based molecular machines where as inorganic method uses diamondoid rigid materials. Cavalcanti and his team have found a new method called” Nanobhis” (Nano-build hardware integrated system) for the fabrication of nanorobots. It is a combination of both traditional and new concepts. Nanorobots are developed using three dimensional computational simulations. Nanoelectrons are fabricated by IC design using ultraviolet lithography. New CMOS technology is used to assemble nanorobots.
2. Applications of nanomedicine:
One main application of nanomedicine in medical field is the delivery of drug to the damaged cells. Some people prefer oral intake of drugs than injecting it through blood vessels. Nanorobots which can deliver the drug orally are under development process. In that nanoparticles are filled with drug n swallowed. It will move around the body. It is programmed in a way that it will be pulled towards the damaged cells and deliver the drug to the cell for the treatment.
Another application of nanomedicine is the therapy technique. Allergies are caused by the mast cells. The mast cells are filled with histamine. When there is a discharge of histamine and heparin into the blood it causes allergy. A nanoparticle called buckyball is responsible for blocking the allergy. Cancer cells can also be destroyed by nanoparticles. In some accident cases the patient might die due to over bleeding. For such cases aluminosilicate nanoparticles can be used to decrease the bleeding by absorbing the water in the blood. When the water is absorbed the blood will coagulate quickly. The research is being developed to implement a nanoparticle that will fight against influenza and other respiratory infections. When people inhale the aerosol spray the antibodies are increased which will strengthen the immune power in the body. So if there is any viral infection in the air the person will not get affected easily. This is more convenient for both doctors and patients, otherwise the doctor has to find out the virus and give medicine that will fight against the virus. Another application is that it will be used to fix the damaged cell (NetLine Corporation, 2010).
3. Design and Manufacturing of nanorobot:
Current method of manufacturing products causes pollution to the environment. But with molecular manufacturing methods there is no pollution to the environment. When there is any development in the technology it will have good as well as bad effects to the environment. The bad effect happens by accidents or by misuse. The misuse of the technology should be prevented. Accidents happens when the molecular machine replicate itself (Merkle, 2001).
There are certain processes that have to be done for designing a complete artificial nanorobot. The first step is that the basic concepts should be successful. Once that is done then basic components assembly and computational simulation are carried out. The next step is manufacturing and testing. Finally it is tested clinically. According to Cavalcanti and Freitas (2005) the design of the nanorobot should be carried out in virtual reality approach. Computer graphics can be used in the manipulation of nano particles.
For a successful development of nanorobot, first the parts of the nanorobot should be designed, created and analyzed. Some nanorobot parts are molecular bearing, molecular gears and nanocomputers. The design of molecular bearing is very easy because of its simple structure and operation. The molecular gears have a central shaft that rotates very fast and the outside shaft rotates slowly. Ring gear is the one that keeps the planet in proper position. Nanocomputer is an important part in the nanorobot. It will be very useful for the doctors to monitor their work and control it (Freitas, 2005).
A single nanorobot cannot be used for the complete function of a task. Many nanorobots should be interconnected for a full function. Nanorobots should communicate with each other with a help of waves to coordinate with each other (Requicha, 2003). The nanorobot design is composed of robot arm and molecular sorting rotors. To maintain the nanorobot's position and its orientation, macrotransponder navigational system can be used. Signals that are generated by beacons from outside the skin can also be used (Cavalcanti, 2003). So the organ inlets which act as delivery points for the protein delivery will be placed in a correct position. Two types of sensors are used in nanorobots to detect the occurrence of collision.
4. Uses of nanorobots in medicine:
Nanorobots can be used in the treatment of diseases by diagnosis and can supply drug to the damaged cells. To identify a disease, the necessary devices should be built inside the nanorobot. So that it can monitor the conditions of the human body. Some of the parameters which are monitored using these devices are chemical concentration in the blood, temperature and electromagnetic signatures.
4.1 Cancer treatment:
Nanorobot can be used to find cancer in the early stages and will help to deliver the drug to the body. E-cardherin and beta catenin levels are the two key parameters used to detect the cancer. So the nanobiosensors inside nanorobot can find these levels and diagnose the disease. Then the nanorobot will deliver the drug in timely basis according to the need. New 3D software called NCD is created for nanorobot modeling. It is used for the architecture analysis and control design of the system. Diagnosis and therapeutic applications using nanorobot can be done by administrating the nanorobot into the vein. So it is injected into the patient's blood vessel. Therapeutic efficiency can be determined by the drug storage in the tumor. The side effects caused by chemotherapy can be reduced by nanorobot. The best method is to combine nanorobot architecture with DNA-CNT CMOS. This method is based on proteomic and bioelectronics signals. It checks the changes in the signals and controls the drug delivery accordingly (Cavalcanti et al., 2008).
Target identification is mainly based on the changes in the chemical and thermal signals. The task of the nanorobot is to move through a vessel filled with fluid and to locate the target region using chemical and thermal changes. In the 3D structure there is nanorobot, biomolecules and delivery points. The organ inlets are closed when the chemical concentrations are in the needed level. When the chemical concentrations are not in the desired levels the organ inlets are opened. This indicates that it needs protein supply. Different sets of sensors and actuators can be used to identify the different diseases. As per the architecture design external sensors are also used in nanorobot. It is used as an information tool when there is a change in the temperature or chemical signal near the target region (Cavalcanti et al., 2008).Normally if there is any change in the human body the temperature will increase. This can be used as an important parameter for identifying the target region. When there is a need for the protein the organ inlets will emit chemical and thermal signals. By receiving this signal the nanorobot will supply the protein through organ inlets.
4.2 Brain aneurysm:
Brain aneurysm can be found out with nanorobots. When there is a deformation of vessel the bulb is developed in that area. This is called as brain aneurysm. So the nanorobot should be able to find the deformation of the vessel before the bulb development. The current method uses ultrasound computer tomography to monitor the aneurysm. Nanorobot uses nanobiosensors to find the over secretion of NOS protein inside the blood vessel (Cavalcanti et al., 2009). Always nanorobot should consist of small number of nano devices to minimize the hardware size of it so that it will be easy for the function inside the body.
Mobile phones can be used for obtaining wireless data transmitted from the nanorobot which operate inside the human body. It can act as a powerful device for observing the predefined patterns and it will be useful for the treatment. For this purpose the nanorobot is implemented with nanosensors which will check the NOS level in the blood vessel. If there is any over secretion of NOS protein an alarm is send by the nanorobot inside the body to indicate the aneurysm start. The mobile phone can find the current position of the nanorobot inside the human body using electromagnetic waves (Zadeh and Fry, 2008).
Aneurysm can be detected in the beginning stage of its growth by measuring the changes in the chemical rates. This will help the doctors to start the treatment before the patient get an intracranial stroke. Different levels of NOS signal patterns can be identified by chemical sensors which are enclosed as nanoelectronics in nanorobots. Concentration of NOS in the blood stream is identified by nanobiosensor and asynchronous IC architecture is used to perform the nanorobot computation.
5. Diabetes control model:
Many people have diabetes now days. Diabetes patients' glucose level should be checked many times a day. Small blood samples are taken many times a day to check the glucose level in the blood. This method is very difficult and uneasy. For this purpose a nanorobot can be used to check the glucose level of the patient. This is easy for the doctors to give medical treatment. With this kind of monitoring there is no pain for the patient and the patient will concentrate more on the daily intake of proteins and calories. Many nanorobots should work simultaneously and monitor the glucose level in many locations of the body. So that it will be easy for the doctor to see the glucose concentration in the whole body. Diabetes patient with high blood pressure is more dangerous and complicated. So the blood pressure of the patient should be checked regularly. Nano biosensor can be used to measure the blood pressure regularly. The glucose level should be checked when the patient is doing different actions like eating, walking, sleeping, etc. The nanobiosensor will note all the readings and send. This will be easy for the doctor to start the treatment.
5.1 Architecture:
Nanorobot should be designed carefully with number of nano devices, so that it can monitor the changes in the human body and function properly. To achieve this VLSI chip should be designed to provide some capabilities like processing and transmission of data and supply energy for the process. Developments in bioelectronics should results in the fully operational nanorobots. Nanodevices and nanoelectronics systems are manufactured using CMOS VLSI design which uses deep ultraviolet lithography.
5.1.1 Chemical sensor:
Different set of chemical and biological sensors are used to detect different medical targets. A recent study explains that biomolecules are detected by voltage changes using an IC CMOS based nanobiosensor, where its architecture has nanogaps of 200nm length. Circuits in CMOS based sensors which uses nanowires as the material can have maximum efficiency for chemical changes. Thermal coupling and self heating for CMOS functionality can be decreased by sensors that use nanowires for silicon circuits. The advantages of nanosensors are high sensitivity and less consumption of energy. Sub threshold slop and quantum mechanical tunneling are the barriers for the improvement of BICMOS, CMOS and MOSFET methodologies. These limitations can be solved by reducing the channel length and voltage circuitry for higher performance. Self heating can be reduced by strained channel with relaxed SiGe. High performance logic sub 90nm circuit assembled by SOI technology can be used to advance the manufacturing techniques. When there are more developments and improvements in nanotechnology size, mass and power consumption of the sensor can be reduced (Zadeh and Fry, 2008).
5.1.2 Power supply:
Power supply is considered to be one of the important factors in the nanorobot's operation. When the nanorobot is inside the body it needs continuous power supply for its function. CMOS technique is used for the power supply. The same technique is also used for the transmission of data between the nanorobot and the external substance. Monitoring of the patient and transmission of power with the use of inductive coupling are done with RF based telemetry procedures. Depends on the signal patterns the nanorobot will be in active or passive modes. Some tasks need only less power if the nanorobot is in active mode. 1mW power is needed for the transmission of RF signals for communication. The whole weight of the nanorobot is approximately 0.2 grams. When all the nanorobots work simultaneously and move at the same time they require just 1W power, which can be supplied by electromagnetic coupling energy. Mobile phone is one of the important devices in the implementation of architecture. It can transfer energy and data to the nanorobot. The communication and energy transfer control software should be uploaded in the mobile phone. Once that is uploaded mobile phone can be used to transfer energy and data to the nanorobot and control the working of the nanorobot.
5.1.3 Data transmission:
For the data transfer in implanted devices integrated sensors are useful for reading and writing the data. Various options for transmitting the data in liquid workspace are acoustic, RF, light or chemical signals. For short distance communication chemical signaling is effective and for long distance communication acoustic signaling is more effective, with less consumption of energy. Optical communication can transmits the data very fast but it is not suitable for nanorobots as it requires high energy. Mobile phones can be used as sensors for obtaining wireless data transmission which is send from the nanorobot inside the human body. So the mobile phone can act as a good device for observing the predefined patterns and will be useful for the treatment. For this purpose the nanorobot is implemented with nanosensors which will check the glucose level in the blood. Mobile phones can be used for communication of data. Current position of the nanorobot inside the body can be obtained by mobile phones using electromagnetic radio waves.
Antenna frequency inside the body is set by considering the electrical characteristics of muscle, fat and skin tissue because it may tamper the data transmitted from other devices inside the body. For this purpose a new IEEE 802.15.4 protocol has been implemented. With the use of this protocol mobile phones can be used for transmission of data and energy supply to other devices inside the human body. Mobile phone can communicate with nanorobot using transmitter antenna with 400 MHz frequency bandwidth. In turn nanorobot can act as a loop antenna with 20 MHz frequency bandwidth (Cavalcanti, Shirinzadeh and Kretly, 2008).
5.1.4 Lifetime:
The lifetime of the sensor can be increased by choosing proper material for the development. Polymer material is considered as the best material that it will protect the sensor from aggressive action of enzymes. A specific anti glycocalyx compound hyaluronidase is filled in the nanorobot. When the lifetime of the nanorobot is over or if the physician decided to stop the treatment RF signal is send to the nanorobot which is functioning inside the body. As soon as the nanorobot receives the RF command it will leak the hyalyronidase inside the body. So the immune system will withdraw the nanorobot out from the body. The next nanorobot injection or course is started only after one week. So that it will clean the previous nanorobot completely from the body.
6. Conclusion:
Even though there are many barriers for the full implementation of nanorobots, it can be solved by more research and developments in the technology. Human mind is not stable and each person will have different opinions and views. All the patients will not agree to inject the nanorobot inside their body for the treatment unless they have demonstration and all safety measures. Even though there are many problems and complications in the development of nanorobot, the researchers are working hard to implement a fully functional artificial nanorobot in the medical field. If a successful nanorobot comes into practice then it will be easy to identify the particular disease and start the treatment in the early stages. This method will be more convenient for both doctors as well as patients.
