Robots in medicine

Today, research teams around the world are trying to grope the concept of using robots in medicine. Although it is more correct, perhaps, to say "have already groped." Judging by the number of developments and the interest of various scientific groups, it can be argued that the creation of medical microrobots was the mainstream. This also includes robots with the prefix "nano-". And the first successes in this area were achieved relatively recently, only eight years ago.



In 2006, a group of researchers led by Silvan Martel for the first time in the world conducted a successful experiment by launching a tiny robot the size of a ball from a pen into the carotid artery of a live pig. At the same time, the robot moved through all the “waypoints” assigned to it. And over the years since then, microrobotics has advanced somewhat.



One of the main goals for engineers today is to create such medical robots that will be able to move not only through large arteries, but also through relatively narrow blood vessels. This would allow complex treatments without such a traumatic surgery.

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But this is not the only potential advantage of microrobots. First of all, they would be useful in the treatment of cancer, deliberately delivering the drug directly to the malignant formation. The value of this possibility is difficult to overestimate: with chemotherapy, drugs are given through an IV line, dealing a severe blow to the entire body. In fact, it is a strong poison that damages many internal organs and, for the company, the tumor itself. This is comparable to carpet bombing for the destruction of a small solitary target.



The task of creating such microrobots is at the junction of a number of scientific disciplines. For example, from the point of view of physics - how to force such a small object to move independently in a viscous fluid, which for it is blood? From an engineering point of view - how to provide the robot with energy and how to track the movement of a tiny object through the body? From the point of view of biology - what materials should be used to make robots so that they do not harm the human body? And ideally, robots should be biodegradable so that they do not have to solve the problem of their removal from the body.



One example of how microrobots can “pollute” a patient’s body is a “bio-rocket”.







This version of the microrobot is a titanium core surrounded by an aluminum shell. The diameter of the robot is 20 microns. Aluminum reacts with water, during which hydrogen bubbles form on the surface of the shell, pushing the entire structure. In the water, such a “bio-rocket” swims in one second a distance equal to 150 of its diameter. This can be compared with a man of two meters in height, who swims 300 meters in a second, 12 pools. Such a chemical engine runs for about 5 minutes due to the addition of gallium, which reduces the intensity of the formation of an oxide film. That is, the maximum power reserve is about 900 mm in water. The direction of movement is given to the robot by an external magnetic field, and it can be used for targeted drug delivery. But only after the “charge” is exhausted, the patient will have a scattering of aluminum-coated microspheres, which does not have a beneficial effect on the human body, unlike biologically neutral titanium.



Microrobots should be so small that traditional technologies simply cannot scale to the desired size. No standard parts of suitable size are also produced. And even if they were made, they would simply not be suitable for such specific needs. And because researchers, as it has been many times in the history of inventions, are looking for inspiration from nature. For example, in the same bacteria. At the micro, and even more so at the nanoscale level, quite different physical laws act. In particular, water is a very viscous liquid. Therefore, it is necessary to apply other engineering solutions to ensure the movement of microrobots. Bacteria are often solved with the help of cilia.



At the beginning of this year, a group of researchers from the University of Toronto created a prototype micro-robot with a length of 1 mm, controlled by an external magnetic field and equipped with two grippers. The developers managed to build a bridge with it. Also this robot can be used not only for drug delivery, but also for mechanical tissue repair in the circulatory system and organs.

Muscular robots

Another interesting trend in micro-robotics is robots driven by muscles. For example, there is such a project: a muscle-stimulated muscle cell to which a robot is attached, whose “ridge” is made of hydrogel.







This system, in fact, copies the natural solution found in the organisms of many mammals. For example, in the human body, muscle contraction is transmitted to the bones through the tendons. In this biorobot, when the cell is reduced by the action of electricity, the "ridge" is bent and the cross bars, playing the role of legs, are attracted to each other. If one of them moves a smaller distance when the ridge is bent, then the robot moves towards this leg.



There is another vision of what medical microrobots should be: soft, repetitive forms of various living beings. For example, here is such a roboe (RoboBee).







True, it is intended not for medical purposes, but for a number of others: pollination of plants, search and rescue operations, detection of toxic substances. The authors of the project, of course, do not blindly copy the anatomical features of the bee. Instead, they carefully analyze all sorts of "designs" of organisms of various insects, adapting and embodying them in mechanics.



Or another example of the use of the “structures” found in nature is a microrobot in the form of a bivalve mollusk. It moves by slamming the flaps, thereby creating a jet stream. With a size of about 1 mm, it can float inside the human eyeball. Like most other medical robots, this “mollusk” uses an external magnetic field as an energy source. But there is an important difference - it only receives energy for movement, the field itself does not move it, unlike most other types of microrobots.

Big robots

Of course, the medical equipment park is not limited to microorobots alone. In science fiction films and books, medical robots are usually presented as a replacement for a human surgeon. They say that this is a kind of large device that quickly and very accurately performs all kinds of surgical procedures. And it is not surprising that this idea was implemented one of the first. Of course, modern surgical robots are not able to replace the whole person, but stitching is completely trusted by them. They are also used as a continuation of the surgeon's hands, as manipulators.





However, in a medical environment, disputes over the expediency of using such machines do not subside. Many experts are of the opinion that such robots do not give special benefits , and due to their high price they significantly increase the cost of medical services . On the other hand, there is a study , according to which patients with prostate cancer who underwent surgery with a robot assistant, in the future, less intensive use of hormones and radiotherapy is required. In general, it is not surprising that the efforts of many scientists were aimed at creating microrobots.



An interesting project is the Robonaut, a telemedicine robot designed to assist astronauts. This is still a pilot project, but such an approach can be used not only to render such important and expensive people in training as cosmonauts. Telemedical robots can also be used to provide assistance in various hard-to-reach areas. Of course, it will be expedient only if it is cheaper to install a deaf taiga or mountain robot village in the infirmary than to keep a medical assistant on salary.







And this medical robot is even more narrowly specialized; it is used to treat baldness. ARTAS is engaged in the automatic "digging" of hair follicles from the patient's scalp, based on high-resolution photographs. Then the human physician manually introduces the “crop” into the bald areas.







Still, the world of medical robots is not so monotonous as it may seem to an inexperienced person. Moreover, it is actively developing, there is an accumulation of ideas, results of experiments, the most effective approaches are sought. And who knows, perhaps even during our life the word "surgeon" would mean a doctor not with a scalpel, but with a jar of microrobots, which would be enough to swallow or implant through an IV.