The most important discoveries in the history of medicine

1. Human Anatomy (1538)

Andreas Vesalius analyzes human bodies based on autopsies, lays out detailed information about human anatomy and refutes various interpretations on this topic. Vesalius believes that an understanding of anatomy is critical to performing operations, so he analyzes human cadavers (which is unusual for the time).

His anatomical diagrams of the circulatory and nervous systems, written as a reference to help his students, are copied so often that he is forced to publish them to protect their authenticity. In 1543 he published De Humani Corporis Fabrica, which marked the birth of the science of anatomy.

2. Circulation (1628)

William Harvey discovers that blood circulates throughout the body and names the heart as the organ responsible for blood circulation. His pioneering work, an anatomical sketch of the workings of the heart and blood circulation in animals, published in 1628, formed the basis for modern physiology.

3. Blood types (1902)

Kaprl Landsteiner

Austrian biologist Karl Landsteiner and his group discover four human blood types and develop a classification system. Knowledge of the different types of blood is critical to performing safe blood transfusion, which is now common practice.

4. Anesthesia (1842-1846)

Some scientists have found that certain chemicals can be used as an anesthetic, allowing surgery to be performed without pain. The first experiments with anesthetics - nitrous oxide (laughing gas) and sulfuric ether - began to be used in the 19th century, mainly by dentists.

5. X-rays (1895)

Wilhelm Roentgen accidentally discovers X-rays while experimenting with cathode ray emission (ejection of electrons). He notices that the rays are able to pass through the opaque black paper wrapped around the cathode ray tube. This leads to the glow of the flowers located on the adjacent table. His discovery was a revolution in physics and medicine, earning him the first ever Nobel Prize in Physics in 1901.

6. Theory of germs (1800)

The French chemist Louis Pasteur believes that some microbes are disease-causing agents. At the same time, the origin of diseases such as cholera, anthrax and rabies remains a mystery. Pasteur formulates the germ theory, suggesting that these diseases, and many others, are caused by the corresponding bacteria. Pasteur is called the "father of bacteriology" because his work was the forerunner of new scientific research.

7. Vitamins (early 1900s)

Frederick Hopkins and others discovered that certain diseases were caused by a lack of certain nutrients, which were later called vitamins. In experiments with nutrition on laboratory animals, Hopkins proves that these "nutrition accessory factors" are essential to health.

Education is one of the foundations of human development. Only thanks to the fact that from generation to generation humanity passed on its empirical knowledge, at the moment we can enjoy the benefits of civilization, live in a certain prosperity and without destroying racial and tribal wars for access to the resources of existence.
Education has also penetrated the sphere of the Internet. One of the educational projects was named Otrok.

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8. Penicillin (1920s-1930s)

Alexander Fleming discovered penicillin. Howard Flory and Ernst Boris isolated it in its pure form, creating an antibiotic.

Fleming's discovery happened quite by accident, he noticed that the mold killed a certain type of bacteria in a petri dish that was just lying in the sink of the laboratory. Fleming singles out the specimen and names it Penicillium notatum. In the following experiments, Howard Flory and Ernst Boris confirmed penicillin treatment of mice with bacterial infections.

9. Sulfur preparations (1930)

Gerhard Domagk discovers that prontosil, an orange-red dye, is effective in treating infections caused by the common streptococcus bacteria. This discovery paves the way for the synthesis of chemotherapeutic drugs (or "miracle drugs") and the production of sulfanilamide drugs in particular.

10. Vaccination (1796)

Edward Jenner, an English physician, administers the first smallpox vaccination after determining that cowpox inoculation provides immunity. Jenner formulated his theory after noticing that patients who worked with cattle and came into contact with cows did not contract smallpox during an epidemic in 1788.

11. Insulin (1920)

Frederick Banting and his colleagues discovered the hormone insulin, which helps balance blood sugar levels in diabetic patients and allows them to live normal lives. Before the discovery of insulin, it was impossible to save diabetics.

12. Discovery of oncogenes (1975)

13. Discovery of the human retrovirus HIV (1980)

Scientists Robert Gallo and Luc Montagnier separately discovered a new retrovirus, later named HIV (human immunodeficiency virus), and classified it as the causative agent of AIDS (acquired immunodeficiency syndrome).

SPbGPMA

in the history of medicine

History of the development of medical physics

Completed by: Myznikov A.D.,

1st year student

Lecturer: Jarman O.A.

St. Petersburg

Introduction

The birth of medical physics

2. Middle Ages and Modern times

2.1 Leonardo da Vinci

2.2 Iatrophysic

3 Building a microscope

3. History of the use of electricity in medicine

3.1 A little background

3.2 What we owe to Gilbert

3.3 Prize awarded to Marat

3.4 Galvani and Volta controversy

4. Experiments by VV Petrov. The beginning of electrodynamics

4.1 The use of electricity in medicine and biology in the XIX - XX centuries

4.2 History of radiology and therapy

A Brief History of Ultrasound Therapy

Conclusion

Bibliography

medical physics ultrasonic radiation

Introduction

Know yourself and you will know the whole world. The first is medicine, and the second is physics. Since ancient times, the relationship between medicine and physics has been close. It is not for nothing that congresses of natural scientists and doctors were held in different countries together until the beginning of the 20th century. The history of the development of classical physics shows that it was largely created by doctors, and many physical studies were caused by questions raised by medicine. In turn, the achievements of modern medicine, especially in the field of high technologies for diagnosis and treatment, were based on the results of various physical studies.

It was not by chance that I chose this particular topic, because for me, a student of the specialty "Medical Biophysics", it is as close as anyone else. I have long wanted to know how much physics helped the development of medicine.

The purpose of my work is to show how important a role physics has played and is playing in the development of medicine. It is impossible to imagine modern medicine without physics. The tasks are to:

To trace the stages of formation of the scientific base of modern medical physics

Show the importance of the activities of physicists in the development of medicine

1. The birth of medical physics

The paths of development of medicine and physics have always been closely intertwined. Already in ancient times, medicine, along with drugs, used such physical factors as mechanical effects, heat, cold, sound, light. Let's consider the main ways of using these factors in ancient medicine.

Having tamed fire, a person learned (of course, not immediately) to use fire for medicinal purposes. Especially well it turned out among the eastern peoples. Even in ancient times, cauterization was given great importance. Ancient medical books say that moxibustion is effective even when acupuncture and medicine are powerless. When exactly this method of treatment arose is not exactly established. But it is known that it has existed in China since ancient times, and was used in the Stone Age to treat people and animals. Tibetan monks used fire for healing. They made burns on sanmings - biologically active points responsible for one or another part of the body. In the damaged area, the healing process was intensively going on, and it was believed that healing occurred with this healing.

Sound was used by almost all ancient civilizations. Music was used in temples to treat nervous disorders, it was in direct connection with astronomy and mathematics among the Chinese. Pythagoras established music as an exact science. His followers used it to get rid of rage and anger and considered it the main means for raising a harmonious personality. Aristotle also argued that music can influence the aesthetic side of the soul. King David cured King Saul of depression with his harp playing, and also saved him from unclean spirits. Aesculapius treated sciatica with loud trumpet sounds. Tibetan monks are also known (they were discussed above), who used sounds to treat almost all human diseases. They were called mantras - forms of energy in sound, pure essential energy of the sound itself. Mantras were divided into different groups: for the treatment of fevers, intestinal disorders, etc. The method of using mantras is used by Tibetan monks to this day.

Phototherapy, or light therapy (photos - "light"; Greek), has always existed. In ancient Egypt, for example, a special temple was created dedicated to the "healing healer" - light. And in ancient Rome, houses were built in such a way that nothing prevented light-loving citizens from daily indulging in "drinking the sun's rays" - this was the name they used to take sunbaths in special outbuildings with flat roofs (solariums). Hippocrates healed diseases of the skin, nervous system, rickets and arthritis with the help of the sun. Over 2,000 years ago, he called this use of sunlight heliotherapy.

Also in antiquity, the theoretical sections of medical physics began to develop. One of them is biomechanics. Research in biomechanics is as old as research in biology and mechanics. Studies that, according to modern concepts, belong to the field of biomechanics, were already known in ancient Egypt. The famous Egyptian papyrus (The Edwin Smith Surgical Papyrus, 1800 BC) describes various cases of motor injuries, including paralysis due to dislocation of the vertebrae, their classification, treatment methods and prognosis.

Socrates, who lived ca. 470-399 BC, taught that we will not be able to comprehend the world around us until we comprehend our own nature. The ancient Greeks and Romans knew a lot about the main blood vessels and heart valves, they knew how to listen to the work of the heart (for example, the Greek doctor Areteus in the 2nd century BC). Herophilus of Chalcedoc (3rd century BC) distinguished among the vessels arteries and veins.

The father of modern medicine, the ancient Greek physician Hippocrates, reformed ancient medicine, separating it from the methods of treatment with spells, prayers and sacrifices to the gods. In the treatises "Reduction of joints", "Fractures", "Head wounds", he classified the injuries of the musculoskeletal system known at that time and proposed methods for their treatment, in particular mechanical ones, using tight bandages, traction, and fixation. Apparently, already at that time, the first improved limb prostheses appeared, which also served to perform certain functions. In any case, Pliny the Elder has a mention of one Roman commander who participated in the second Punic War (218-210 BC). After the wound he received, his right arm was amputated and replaced with an iron one. At the same time, he could hold a shield with a prosthesis and participated in battles.

Plato created the doctrine of ideas - immutable intelligible prototypes of all things. Analyzing the shape of the human body, he taught that "the gods, imitating the outlines of the universe ... included both divine rotations in a spherical body ... which we now call the head." The device of the musculoskeletal system is understood by him as follows: "so that the head does not roll along the ground, everywhere covered with bumps and pits ... the body became oblong and, according to the plan of God, who made it mobile, grew out of itself four limbs that can be stretched and bent; clinging to them and relying on them, it acquired the ability to move everywhere ... ". Plato's method of reasoning about the structure of the world and man is based on a logical study, which "should go in such a way as to achieve the greatest degree of probability."

The great ancient Greek philosopher Aristotle, whose writings cover almost all areas of science of that time, compiled the first detailed description of the structure and functions of individual organs and body parts of animals and laid the foundations of modern embryology. At the age of seventeen, Aristotle, the son of a physician from Stagira, came to Athens to study at Plato's Academy (428-348 BC). After staying at the Academy for twenty years and becoming one of the closest students of Plato, Aristotle left it only after the death of his teacher. Subsequently, he took up the anatomy and study of the structure of animals, collecting a variety of facts and conducting experiments and dissections. Many unique observations and discoveries were made by him in this area. So, Aristotle first established the heartbeat of a chicken embryo on the third day of development, described the chewing apparatus of sea urchins ("Aristotle's lantern") and much more. In search of the driving force of blood flow, Aristotle proposed a mechanism for the movement of blood associated with its heating in the heart and cooling in the lungs: "the movement of the heart is similar to the movement of a liquid that causes heat to boil." In his works "On the Parts of Animals", "On the Movement of Animals" ("De Motu Animalium"), "On the Origin of Animals", Aristotle for the first time considered the structure of the bodies of more than 500 species of living organisms, the organization of the work of organ systems, introduced a comparative method of research. When classifying animals, he divided them into two large groups - those with blood and bloodless. This division is similar to the current division into vertebrates and invertebrates. According to the method of movement, Aristotle also distinguished groups of two-legged, four-legged, many-legged and legless animals. He was the first to describe walking as a process in which the rotational movement of the limbs is converted into the translational movement of the body, he was the first to note the asymmetric nature of the movement (support on the left leg, weight transfer on the left shoulder, characteristic of right-handed people). Observing the movements of a person, Aristotle noticed that the shadow cast by a figure on the wall does not describe a straight line, but a zigzag line. He singled out and described organs that are different in structure, but identical in function, for example, scales in fish, feathers in birds, and hair in animals. Aristotle studied the conditions for the equilibrium of the body of birds (two-legged support). Reflecting on the movement of animals, he singled out the motor mechanisms: “… what moves with the help of an organ is that in which the beginning coincides with the end, as in a joint. Indeed, in a joint there is a convex and hollow, one of them is the end, the other is the beginning… one rests , the other moves... Everything moves through push or pull." Aristotle was the first to describe the pulmonary artery and introduced the term "aorta", noted the correlations of the structure of individual parts of the body, pointed to the interaction of organs in the body, laid the foundations for the doctrine of biological expediency and formulated the "principle of economy": "what nature takes away in one place, it gives in friend." He was the first to describe the differences in the structure of the circulatory, respiratory, musculoskeletal systems of different animals and their chewing apparatus. Unlike his teacher, Aristotle did not consider the "world of ideas" as something external to the material world, but introduced Plato's "ideas" as an integral part of nature, its main principle organizing matter. Subsequently, this beginning is transformed into the concepts of "vital energy", "animal spirits".

The great ancient Greek scientist Archimedes laid the foundations of modern hydrostatics with his studies of the hydrostatic principles governing a floating body and studies of the buoyancy of bodies. He was the first to apply mathematical methods to the study of problems in mechanics, formulating and proving a number of statements about the equilibrium of bodies and about the center of gravity in the form of theorems. The principle of the lever, widely used by Archimedes to create building structures and military vehicles, will be one of the first mechanical principles applied in the biomechanics of the musculoskeletal system. The works of Archimedes contain ideas about the addition of motions (rectilinear and circular when a body moves in a spiral), about a continuous uniform increase in speed when a body accelerates, which Galileo would later name as the basis of his fundamental works on dynamics.

In the classic work On the Parts of the Human Body, the famous ancient Roman physician Galen gave the first comprehensive description of human anatomy and physiology in the history of medicine. This book has served as a textbook and reference book on medicine for almost one and a half thousand years. Galen laid the foundation for physiology by making the first observations and experiments on living animals and studying their skeletons. He introduced vivisection into medicine - operations and research on a living animal in order to study the functions of the body and develop methods for treating diseases. He discovered that in a living organism the brain controls speech and sound production, that the arteries are filled with blood, not air, and, as best he could, explored the ways in which blood moves in the body, described the structural differences between arteries and veins, and discovered heart valves. Galen did not perform autopsies and, perhaps, therefore, incorrect ideas got into his works, for example, about the formation of venous blood in the liver, and arterial blood - in the left ventricle of the heart. He also did not know about the existence of two circles of blood circulation and the significance of the atria. In his work "De motu musculorum" he described the difference between motor and sensory neurons, agonist and antagonist muscles, and for the first time described muscle tone. He considered the cause of muscle contraction to be "animal spirits" coming from the brain to the muscle along the nerve fibers. Exploring the body, Galen came to the conclusion that nothing is superfluous in nature and formulated the philosophical principle that, by exploring nature, one can come to an understanding of God's plan. In the Middle Ages, even under the omnipotence of the Inquisition, a lot was done, especially in anatomy, which subsequently served as the basis for the further development of biomechanics.

The results of research carried out in the Arab world and in the countries of the East occupy a special place in the history of science: many literary works and medical treatises serve as evidence of this. The Arab physician and philosopher Ibn Sina (Avicenna) laid the foundations of rational medicine, formulated rational grounds for making a diagnosis based on a patient's examination (in particular, an analysis of the pulse fluctuations of the arteries). The revolutionary nature of his approach becomes clear if we remember that at that time Western medicine, dating back to Hippocrates and Galen, took into account the influence of stars and planets on the type and course of the course of the disease and the choice of therapeutic agents.

I would like to say that in most of the works of ancient scientists, the method of determining the pulse was used. The pulse diagnostic method originated many centuries before our era. Among the literary sources that have come down to us, the most ancient are the works of ancient Chinese and Tibetan origin. Ancient Chinese include, for example, "Bin-hu Mo-xue", "Xiang-lei-shih", "Zhu-bin-shih", "Nan-jing", as well as sections in the treatises "Jia-i-ching", "Huang-di Nei-jing Su-wen Lin-shu", etc.

The history of pulse diagnosis is inextricably linked with the name of the ancient Chinese healer - Bian Qiao (Qin Yue-Ren). The beginning of the path of the pulse diagnosis technique is associated with one of the legends, according to which Bian Qiao was invited to treat the daughter of a noble mandarin (official). The situation was complicated by the fact that even doctors were strictly forbidden to see and touch persons of noble rank. Bian Qiao asked for a thin string. Then he suggested tying the other end of the cord to the wrist of the princess, who was behind the screen, but the court healers disdainfully treated the invited doctor and decided to play a trick on him by tying the end of the cord not to the princess’s wrist, but to the paw of a dog running nearby. A few seconds later, to the surprise of those present, Bian Qiao calmly declared that these were impulses not of a person, but of an animal, and this animal tossed with worms. The skill of the doctor aroused admiration, and the cord was transferred with confidence to the princess's wrist, after which the disease was determined and treatment was prescribed. As a result, the princess quickly recovered, and his technique became widely known.

Hua Tuo - successfully used pulse diagnostics in surgical practice, combining it with a clinical examination. In those days, operations were forbidden by law, the operation was performed as a last resort, if there was no confidence in the cure by conservative methods, the surgeons simply did not know diagnostic laparotomies. Diagnosis was made by external examination. Hua Tuo passed on his art of mastering the pulse diagnosis to diligent students. There was a rule that only a man can learn a certain mastery of pulse diagnostics, learning only from a man for thirty years. Hua Tuo was the first to use a special technique for examining students on the ability to use pulses for diagnosis: the patient was seated behind a screen, and his hands were put through the cuts in it so that the student could see and study only the hands. Daily, persistent practice quickly yielded successful results.

2. Middle Ages and Modern times

1 Leonardo da Vinci

In the Middle Ages and the Renaissance, the development of the main sections of physics took place in Europe. A famous physicist of that time, but not only a physicist, was Leonardo da Vinci. Leonardo studied human movements, the flight of birds, the work of heart valves, the movement of plant juice. He described the mechanics of the body when standing and rising from a sitting position, walking uphill and downhill, jumping technique, for the first time described the variety of gaits of people with different physiques, performed a comparative analysis of the gait of a person, a monkey and a number of animals capable of bipedal walking (bear) . In all cases, special attention was paid to the position of the centers of gravity and resistance. In mechanics, Leonardo da Vinci was the first to introduce the concept of resistance that liquids and gases exert on bodies moving in them, and he was the first to understand the importance of a new concept - the moment of force relative to a point - for analyzing the movement of bodies. Analyzing the forces developed by muscles and having excellent knowledge of anatomy, Leonardo introduced the lines of action of forces along the direction of the corresponding muscle and thereby anticipated the concept of the vector nature of forces. When describing the action of muscles and the interaction of muscle systems when performing a movement, Leonardo considered cords stretched between muscle attachment points. To designate individual muscles and nerves, he used letter designations. In his works one can find the foundations of the future doctrine of reflexes. Observing muscle contractions, he noted that contractions can occur involuntarily, automatically, without conscious control. Leonardo tried to translate all the observations and ideas into technical applications, left numerous drawings of devices designed for various kinds of movements, from water skis and gliders to prostheses and prototypes of modern wheelchairs for the disabled (more than 7 thousand sheets of manuscripts in total). Leonardo da Vinci conducted research on the sound generated by the movement of the wings of insects, described the possibility of changing the pitch of the sound when the wing is cut or smeared with honey. Conducting anatomical studies, he drew attention to the features of the branching of the trachea, arteries and veins in the lungs, and also pointed out that an erection is a consequence of blood flow to the genitals. He carried out pioneering studies of phyllotaxis, describing the patterns of leaf arrangement of a number of plants, made imprints of vascular-fibrous leaf bundles and studied the features of their structure.

2 Iatrophysics

In the medicine of the 16th-18th centuries, there was a special direction called iatromechanics or iatrophysics (from the Greek iatros - doctor). The works of the famous Swiss physician and chemist Theophrastus Paracelsus and the Dutch naturalist Jan Van Helmont, known for his experiments on the spontaneous generation of mice from wheat flour, dust and dirty shirts, contained a statement about the integrity of the body, described in the form of a mystical beginning. Representatives of a rational worldview could not accept this and, in search of rational foundations for biological processes, they put mechanics, the most developed field of knowledge at that time, as the basis for their study. Iatromechanics claimed to explain all physiological and pathological phenomena based on the laws of mechanics and physics. The well-known German physician, physiologist and chemist Friedrich Hoffmann formulated a peculiar credo of iatrophysics, according to which life is movement, and mechanics is the cause and law of all phenomena. Hoffmann viewed life as a mechanical process, during which the movements of the nerves along which the “animal spirit” (spiritum animalium) located in the brain moves, control muscle contractions, blood circulation and heart function. As a result, the body - a kind of machine - is set in motion. At the same time, mechanics was considered as the basis of the vital activity of organisms.

Such claims, as is now clear, were largely untenable, but iatromechanics opposed scholastic and mystical ideas, introduced many important hitherto unknown factual information and new instruments for physiological measurements into use. For example, according to the views of one of the representatives of iatromechanics, Giorgio Baglivi, the hand was likened to a lever, the chest to bellows, the glands to sieves, and the heart to a hydraulic pump. These analogies are quite reasonable today. In the 16th century, in the works of the French army doctor A. Pare (Ambroise Pare), the foundations of modern surgery were laid and artificial orthopedic devices were proposed - leg, arm, hand prostheses, the development of which was based more on a scientific foundation than on a simple imitation of a lost form. In 1555, in the works of the French naturalist Pierre Belon, the hydraulic mechanism for the movement of sea anemones was described. One of the founders of iatrochemistry, Van Helmont, studying the processes of food fermentation in animal organisms, became interested in gaseous products and introduced the term "gas" into science (from the Dutch gisten - to ferment). A. Vesalius, W. Harvey, J. A. Borelli, R. Descartes were involved in the development of the ideas of iatromechanics. Iatromechanics, which reduces all processes in living systems to mechanical ones, as well as iatrochemistry, dating back to Paracelsus, whose representatives believed that life is reduced to chemical transformations of the chemicals that make up the body, led to a one-sided and often incorrect idea about the processes of vital activity and methods of treating diseases. Nevertheless, these approaches, especially their synthesis, made it possible to formulate a rational approach in medicine in the 16th-17th centuries. Even the doctrine of the possibility of spontaneous generation of life played a positive role, casting doubt on the religious hypotheses about the creation of life. Paracelsus created "the anatomy of the essence of man", which he tried to show that "in the human body, three ubiquitous ingredients were connected in a mystical way: salts, sulfur and mercury" .

Within the framework of the philosophical concepts of that time, a new iatro-mechanical idea of ​​the essence of pathological processes was being formed. Thus, the German physician G. Chatl created the doctrine of animism (from lat.anima - soul), according to which the disease was considered as movements performed by the soul to remove foreign harmful substances from the body. The representative of iatrophysics, the Italian doctor Santorio (1561-1636), professor of medicine in Padua, believed that any disease is a consequence of a violation of the patterns of movement of individual smallest particles of the body. Santorio was one of the first to apply the experimental method of research and mathematical data processing, and created a number of interesting instruments. In a special chamber he designed, Santorio studied metabolism and for the first time established the variability of body weight associated with life processes. Together with Galileo, he invented a mercury thermometer for measuring the temperature of bodies (1626). In his work "Static Medicine" (1614), the provisions of iatrophysics and iatrochemistry are simultaneously presented. Further research led to revolutionary changes in the understanding of the structure and work of the cardiovascular system. Italian anatomist Fabrizio d "Aquapendente discovered venous valves. Italian researcher P. Azelli and Danish anatomist T. Bartholin discovered lymphatic vessels.

The English physician William Harvey owns the discovery of the closure of the circulatory system. While studying in Padua (in 1598-1601), Harvey listened to the lectures of Fabrizio d "Aquapendente and, apparently, attended the lectures of Galileo. In any case, Harvey was in Padua, while the fame of Galileo's brilliant lectures, which were attended by many, thundered there. Harvey's discovery of circulatory closure was the result of a systematic application of the quantitative method of measurement developed earlier by Galileo, and not a simple observation or guesswork.Harvey made a demonstration in which he showed that blood moves from the left ventricle of the heart in only one direction By measuring the volume of blood ejected by the heart in one contraction (stroke volume), he multiplied the resulting number by the frequency of contractions of the heart and showed that in an hour it pumps a volume of blood much greater than the volume of the body.Thus it was concluded that a much smaller volume of blood must continuously circulate in a vicious circle, entering the heart and pumping to them through the vascular system. The results of the work were published in the work "Anatomical study of the movement of the heart and blood in animals" (1628). The results of the work were more than revolutionary. The fact is that since the time of Galen it was believed that blood is produced in the intestines, from where it enters the liver, then to the heart, from where it is distributed through the system of arteries and veins to other organs. Harvey described the heart, divided into separate chambers, as a muscular sac that acts as a pump that pumps blood into the vessels. Blood moves in a circle in one direction and enters the heart again. The reverse flow of blood in the veins is prevented by the venous valves discovered by Fabrizio d'Akvapendente. Harvey's revolutionary doctrine of blood circulation contradicted Galen's statements, in connection with which his books were sharply criticized and even patients often refused his medical services. Since 1623, Harvey served as the court physician of Charles I and the highest patronage saved him from the attacks of opponents and provided the opportunity for further scientific work.Harvey performed extensive research on embryology, described the individual stages of development of the embryo ("Studies on the Birth of Animals", 1651).The 17th century can be called the era of hydraulics and hydraulic thinking.Advances in technology contributed to the emergence of new analogies and a better understanding of the processes occurring in living organisms. This is probably why Harvey described the heart as a hydraulic pump pumping blood through the "pipeline" of the vascular system. To fully recognize the results of Harvey's work, it was only necessary to find the missing link that closes the circle between arteries and veins, which will be done soon in the works of Malpighi. lungs and the reasons for pumping air through them remained incomprehensible to Harvey - the unprecedented successes of chemistry and the discovery of the composition of air were still ahead.The 17th century is an important milestone in the history of biomechanics, since it was marked not only by the appearance of the first printed works on biomechanics, but also by the formation of a new look on life and the nature of biological mobility.

The French mathematician, physicist, philosopher and physiologist René Descartes was the first who tried to build a mechanical model of a living organism, taking into account control through the nervous system. His interpretation of physiological theory based on the laws of mechanics was contained in a posthumously published work (1662-1664). In this formulation, for the first time, the cardinal idea for the life sciences of regulation through feedback was expressed. Descartes considered a person as a bodily mechanism set in motion by "living spirits" that "constantly ascend in large numbers from the heart to the brain, and from there through the nerves to the muscles and set all members in motion." Without exaggerating the role of "spirits", in the treatise "Description of the human body. On the formation of an animal" (1648), he writes that knowledge of mechanics and anatomy allows us to see in the body "a significant number of organs, or springs" for organizing the movement of the body. Descartes likens the work of the body to a clock mechanism, with separate springs, cogs, gears. In addition, Descartes studied the coordination of movements of various parts of the body. Conducting extensive experiments on the study of the work of the heart and the movement of blood in the cavities of the heart and large vessels, Descartes does not agree with Harvey's concept of heart contractions as the driving force of blood circulation. He defends the hypothesis ascending in Aristotle about the heating and thinning of blood in the heart under the influence of the warmth inherent in the heart, the promotion of expanding blood into large vessels, where it cools, and "the heart and arteries immediately fall down and contract." Descartes sees the role of the respiratory system in the fact that breathing "brings enough fresh air into the lungs so that the blood coming there from the right side of the heart, where it liquefies and, as it were, turns into vapor, again turns from vapor into blood." He also studied eye movements, used the division of biological tissues according to mechanical properties into liquid and solid. In the field of mechanics, Descartes formulated the law of conservation of momentum and introduced the concept of momentum.

3 Building a microscope

The invention of the microscope, an instrument so important for all science, is primarily due to the influence of the development of optics. Some optical properties of curved surfaces were known even to Euclid (300 BC) and Ptolemy (127-151), but their magnifying power did not find practical application. In this regard, the first glasses were invented by Salvinio deli Arleati in Italy only in 1285. In the 16th century, Leonardo da Vinci and Maurolico showed that small objects are best studied with a magnifying glass.

The first microscope was created only in 1595 by Z. Jansen. The invention consisted in the fact that Zacharius Jansen mounted two convex lenses inside one tube, thereby laying the foundation for the creation of complex microscopes. Focusing on the object under study was achieved by a retractable tube. The magnification of the microscope was from 3 to 10 times. And it was a real breakthrough in the field of microscopy! Each of his next microscope, he significantly improved.

During this period (XVI century) Danish, English and Italian research instruments gradually began to develop, laying the foundation for modern microscopy.

The rapid spread and improvement of microscopes began after Galileo (G. Galilei), improving the telescope he designed, began to use it as a kind of microscope (1609-1610), changing the distance between the objective and the eyepiece.

Later, in 1624, having achieved the manufacture of shorter focus lenses, Galileo significantly reduced the dimensions of his microscope.

In 1625, I. Faber, a member of the Roman "Academy of the Vigilant" ("Akudemia dei lincei"), proposed the term "microscope". The first successes associated with the use of a microscope in scientific biological research were achieved by R. Hooke, who was the first to describe a plant cell (about 1665). In his book "Micrographia" Hooke described the structure of the microscope.

In 1681, the Royal Society of London in their meeting discussed in detail the peculiar situation. The Dutchman Levenguk (A. van Leenwenhoek) described the amazing miracles that he discovered with his microscope in a drop of water, in an infusion of pepper, in the mud of a river, in the hollow of his own tooth. Leeuwenhoek, using a microscope, discovered and sketched the spermatozoa of various protozoa, details of the structure of bone tissue (1673-1677).

"With the greatest amazement, I saw in the drop a great many small animals moving briskly in all directions, like a pike in water. The smallest of these tiny animals is a thousand times smaller than the eye of an adult louse."

3. History of the use of electricity in medicine

3.1 A little background

Since ancient times, man has tried to understand the phenomena in nature. Many ingenious hypotheses explaining what is happening around a person appeared at different times and in different countries. The thoughts of Greek and Roman scientists and philosophers who lived before our era: Archimedes, Euclid, Lucretius, Aristotle, Democritus and others - still help the development of scientific research.

After the first observations of electrical and magnetic phenomena by Thales of Miletus, interest in them periodically arose, determined by the tasks of healing.

Rice. 1. Experience with an electric ramp

It should be noted that the electrical properties of some fish, known in ancient times, are still an undisclosed secret of nature. So, for example, in 1960, at an exhibition organized by the British Scientific Royal Society in honor of the 300th anniversary of its foundation, among the mysteries of nature that a person has to solve, an ordinary glass aquarium with a fish in it - an electric stingray (Fig. one). A voltmeter was connected to the aquarium through metal electrodes. When the fish was at rest, the voltmeter needle was at zero. When the fish moved, the voltmeter showed a voltage that reached 400 V during active movements. The inscription read: "The nature of this electrical phenomenon, observed long before the organization of the English royal society, a person still cannot unravel."

2 What do we owe to Gilbert?

The therapeutic effect of electrical phenomena on a person, according to observations that existed in ancient times, can be considered as a kind of stimulating and psychogenic remedy. This tool was either used or forgotten about. For a long time there was no serious study of the electrical and magnetic phenomena themselves, and especially of their action as a remedy, was not carried out.

The first detailed experimental study of electrical and magnetic phenomena belongs to the English physician-physicist, later court physician William Gilbert (Gilbert) (1544-1603 vols.). Gilbert was deservedly considered an innovative physician. Its success was largely determined by the conscientious study and then the application of ancient medical means, including electricity and magnetism. Gilbert understood that without a thorough study of electrical and magnetic radiation, it is difficult to use "fluids" in treatment.

Disregarding fantastic, untested conjectures and unsubstantiated assertions, Gilbert conducted a variety of experimental studies of electrical and magnetic phenomena. The results of this first ever study of electricity and magnetism are grandiose.

First of all, Gilbert for the first time expressed the idea that the magnetic needle of the compass moves under the influence of the magnetism of the Earth, and not under the influence of one of the stars, as was believed before him. He was the first to carry out artificial magnetization, established the fact of the inseparability of magnetic poles. Studying electrical phenomena simultaneously with magnetic ones, Gilbert, on the basis of numerous observations, showed that electrical radiation arises not only when amber is rubbed, but also when other materials are rubbed. Paying tribute to amber - the first material on which electrization was observed, he calls them electrical, based on the Greek name for amber - electron. Consequently, the word "electricity" was introduced into life at the suggestion of a doctor on the basis of his research, which became historical, which laid the foundation for the development of both electrical engineering and electrotherapy. At the same time, Gilbert successfully formulated the fundamental difference between electrical and magnetic phenomena: "Magnetism, like gravity, is a certain initial force emanating from bodies, while electrification is due to the squeezing out of the body's pores of special outflows as a result of friction."

In essence, before the work of Ampère and Faraday, that is, for more than two hundred years after the death of Gilbert (the results of his research were published in the book On the Magnet, Magnetic Bodies, and the Great Magnet - the Earth, 1600), electrification and magnetism were considered in isolation.

P. S. Kudryavtsev in the History of Physics quotes the words of the great representative of the Renaissance, Galileo: they have not been studied carefully ... I have no doubt that over time this branch of science (we are talking about electricity and magnetism - V.M.) will make progress both as a result of new observations, and especially as a result of a strict measure of evidence.

Gilbert died on November 30, 1603, having bequeathed all the instruments and works he had created to the Medical Society of London, of which he was an active chairman until his death.

3 Prize awarded to Marat

Eve of the French bourgeois revolution. Let us summarize the research in the field of electrical engineering of this period. The presence of positive and negative electricity was established, the first electrostatic machines were built and improved, Leyden banks (a kind of charge storage capacitors), electroscopes were created, qualitative hypotheses of electrical phenomena were formulated, bold attempts were made to investigate the electrical nature of lightning.

The electrical nature of lightning and its effect on humans further strengthened the view that electricity can not only strike people, but also heal people. Let's give some examples. On April 8, 1730, the British Gray and Wheeler carried out the now classic experiment with the electrification of man.

In the courtyard of the house where Gray lived, two dry wooden poles were dug into the ground, on which a wooden beam was fixed. Two hair ropes were thrown over the wooden beam. Their lower ends were tied. The ropes easily supported the weight of the boy who agreed to take part in the experiment. Having settled down, as on a swing, the boy with one hand held a rod or a metal rod electrified by friction, to which an electric charge was transferred from an electrified body. With the other hand, the boy threw coins one by one into a metal plate that was on a dry wooden board below him (Fig. 2). The coins acquired a charge through the boy's body; falling, they charged a metal plate, which began to attract pieces of dry straw located nearby. The experiments were carried out many times and aroused considerable interest not only among scientists. The English poet George Bose wrote:

Mad Grey, what did you really know About the properties of that force, hitherto unknown? Are you allowed, fool, to take risks And connect a person with electricity?

Rice. 2. Experience with the electrification of man

The Frenchmen Dufay, Nollet and our compatriot Georg Richman almost simultaneously, independently of each other, designed a device for measuring the degree of electrification, which significantly expanded the use of electric discharge for treatment, and it became possible to dose it. The Paris Academy of Sciences devoted several meetings to discussing the effect of the discharge of Leyden cans on a person. Louis XV also became interested in this. At the request of the king, the physicist Nollet, together with the physician Louis Lemonnier, conducted an experiment in one of the large halls of the Palace of Versailles, demonstrating the prickling effect of static electricity. The benefits of "court amusements" were: many were interested in them, many began to study the phenomena of electrification.

In 1787, the English physician and physicist Adams created for the first time a special electrostatic machine for medical purposes. He widely used it in his medical practice (Fig. 3) and received positive results, which can be explained by the stimulating effect of the current, and the psychotherapeutic effect, and the specific effect of the discharge on a person.

The era of electrostatics and magnetostatics, to which everything mentioned above belongs, ends with the development of the mathematical foundations of these sciences, carried out by Poisson, Ostrogradsky, Gauss.

Rice. 3. Electrotherapy session (from an old engraving)

The use of electrical discharges in medicine and biology has received full recognition. Muscle contraction caused by touching electric rays, eels, catfish, testified to the action of an electric shock. The experiments of the Englishman John Warlish proved the electric nature of the impact of the stingray, and the anatomist Gunther gave an accurate description of the electric organ of this fish.

In 1752, the German physician Sulzer published a message about a new phenomenon he had discovered. The tongue touching two dissimilar metals at the same time causes a peculiar sour taste sensation. Sulzer did not assume that this observation represents the beginning of the most important scientific areas - electrochemistry and electrophysiology.

Interest in the use of electricity in medicine increased. The Academy of Rouen announced a competition for the best work on the topic: "Determine the degree and conditions under which you can count on electricity in the treatment of diseases." The first prize was awarded to Marat, a doctor by profession, whose name went down in the history of the French Revolution. The appearance of Marat's work was timely, since the use of electricity for treatment was not without mysticism and quackery. A certain Mesmer, using fashionable scientific theories about sparking electrical machines, began to claim that in 1771 he had found a universal medical remedy - "animal" magnetism, acting on the patient at a distance. They opened special medical offices, where there were electrostatic machines of sufficiently high voltage. The patient had to touch the current-carrying parts of the machine, while he felt an electric shock. Apparently, cases of the positive effect of being in Mesmer's "medical" offices can be explained not only by the irritating effect of an electric shock, but also by the action of ozone, which appears in rooms where electrostatic machines worked, and the phenomena mentioned earlier. Could have a positive effect on some patients and a change in the content of bacteria in the air under the influence of air ionization. But Mesmer did not suspect this. After the disastrous failures that Marat timely warned about in his work, Mesmer disappeared from France. Created with the participation of the largest French physicist Lavoisier, the government commission to investigate the "medical" activities of Mesmer failed to explain the positive effect of electricity on humans. Treatment with electricity in France temporarily stopped.

4 Dispute between Galvani and Volta

And now we will talk about studies carried out almost two hundred years after the publication of Gilbert's work. They are associated with the names of the Italian professor of anatomy and medicine Luigi Galvani and the Italian professor of physics Alessandro Volta.

In the anatomy laboratory of the University of Boulogne, Luigi Galvani conducted an experiment, the description of which shocked scientists all over the world. Frogs were dissected on the laboratory table. The task of the experiment was to demonstrate and observe the naked, the nerves of their limbs. On this table was an electrostatic machine, with the help of which a spark was created and studied. Here are the statements of Luigi Galvani himself from his work "On Electric Forces during Muscular Movements": "... One of my assistants accidentally very lightly touched the frog's internal femoral nerves with a point. The frog's foot twitched sharply." And further: "... This succeeds when a spark is extracted from the condenser of the machine."

This phenomenon can be explained as follows. A changing electric field acts on the atoms and molecules of air in the zone where the spark occurs, as a result they acquire an electric charge, ceasing to be neutral. The resulting ions and electrically charged molecules propagate to a certain, relatively small distance from the electrostatic machine, since when moving, colliding with air molecules, they lose their charge. At the same time, they can accumulate on metal objects that are well insulated from the earth's surface, and are discharged if a conductive electrical circuit to earth occurs. The floor in the laboratory was dry, wooden. He well isolated the room where Galvani worked from the ground. The object on which the charges accumulated was a metal scalpel. Even a slight touch of the scalpel on the frog's nerve led to a "discharge" of static electricity accumulated on the scalpel, causing the paw to withdraw without any mechanical damage. In itself, the phenomenon of secondary discharge caused by electrostatic induction was already known at that time.

The brilliant talent of the experimenter and the conduct of a large number of versatile studies allowed Galvani to discover another phenomenon important for the further development of electrical engineering. There is an experiment on the study of atmospheric electricity. To quote Galvani himself: "... Tired... of vain expectation... began... to press the copper hooks stuck into the spinal cord against the iron bars - the frog's legs shrunk." The results of the experiment, carried out no longer outdoors, but indoors in the absence of any working electrostatic machines, confirmed that the contraction of the frog muscle, similar to the contraction caused by the spark of an electrostatic machine, occurs when the body of the frog is touched simultaneously by two different metal objects - a wire and plate of copper, silver or iron. No one had observed such a phenomenon before Galvani. Based on the results of observations, he draws a bold unambiguous conclusion. There is another source of electricity, it is "animal" electricity (the term is equivalent to the term "electrical activity of living tissue"). A living muscle, Galvani argued, is a capacitor like a Leyden jar, positive electricity accumulates inside it. The frog nerve serves as an internal "conductor". Attaching two metal conductors to a muscle causes an electric current to flow, which, like a spark from an electrostatic machine, causes the muscle to contract.

Galvani experimented in order to obtain an unambiguous result only on frog muscles. Perhaps this is what allowed him to propose using the "physiological preparation" of the frog's foot as a meter for the amount of electricity. A measure of the amount of electricity, for which such a physiological indicator served, was the activity of raising and falling of the paw when it came into contact with a metal plate, which was simultaneously touched by a hook passing through the spinal cord of the frog, and the frequency of raising the paw per unit time. For some time, such a physiological indicator was used even by prominent physicists, and in particular by Georg Ohm.

Galvani's electrophysiological experiment allowed Alessandro Volta to create the first electrochemical source of electrical energy, which, in turn, opened a new era in the development of electrical engineering.

Alessandro Volta was one of the first to appreciate Galvani's discovery. He repeats Galvani's experiments with great care and receives a lot of data confirming his results. But already in his first articles "On Animal Electricity" and in a letter to Dr. Boronio dated April 3, 1792, Volta, in contrast to Galvani, who interprets the observed phenomena from the standpoint of "animal" electricity, highlights chemical and physical phenomena. Volta establishes the importance of using dissimilar metals for these experiments (zinc, copper, lead, silver, iron), between which a cloth moistened with acid is laid.

Here is what Volta writes: “In Galvani’s experiments, the source of electricity is a frog. However, what is a frog or any animal in general? First of all, these are nerves and muscles, and they contain various chemical compounds. If the nerves and muscles of the prepared frog are connected to two dissimilar metals, then when such a circuit is closed, an electrical action is manifested. In my last experiment, two dissimilar metals also participated - these are steel (lead) and silver, and the saliva of the tongue played the role of liquid. Closing the circuit with a connecting plate, I created conditions for the continuous movement of electric fluid from one place to another. But I could drop these same metal objects simply into water or into a liquid similar to saliva? What about "animal" electricity?

The experiments carried out by Volta allow us to formulate the conclusion that the source of electrical action is a chain of dissimilar metals when they come into contact with a cloth that is damp or soaked in an acid solution.

In one of the letters to his friend the doctor Vazagi (again an example of a doctor’s interest in electricity), Volta wrote: “I have long been convinced that all action comes from metals, from the contact of which the electrical fluid enters a moist or watery body. On this basis, I believe he has the right to attribute all new electrical phenomena to metals and replace the name "animal electricity" with the expression "metallic electricity".

According to Volt, frog legs are a sensitive electroscope. A historical dispute arose between Galvani and Volta, as well as between their followers - a dispute about "animal" or "metallic" electricity.

Galvani did not give up. He completely excluded metal from the experiment and even dissected frogs with glass knives. It turned out that even in this experiment, the contact of the frog's femoral nerve with its muscle led to a clearly noticeable, although much smaller than with the participation of metals, contraction. This was the first fixation of bioelectrical phenomena, on which modern electrodiagnostics of the cardiovascular and a number of other human systems is based.

Volta is trying to unravel the nature of the discovered unusual phenomena. In front of him, he clearly formulates the following problem: “What is the cause of the emergence of electricity?” I asked myself in the same way as each of you would do it. Reflections led me to one solution: from the contact of two dissimilar metals, for example, silver and zinc, the balance of the electricity in both metals is disturbed. At the point of contact of the metals, positive electricity flows from silver to zinc and accumulates on the latter, while negative electricity condenses on silver. This means that electrical matter moves in a certain direction. When I applied on top of each other plates of silver and zinc without intermediate spacers, that is, the zinc plates were in contact with the silver ones, then their total effect was reduced to zero.To enhance the electrical effect or sum it up, each zinc plate should be brought into contact with only one silver and add up in sequence more pairs. This is achieved precisely by the fact that I put a wet piece of cloth on each zinc plate, thereby separating it from the silver plate of the next pair. "Much of what Volt said does not lose its significance even now, in the light of modern scientific ideas.

Unfortunately, this dispute was tragically interrupted. Napoleon's army occupied Italy. For refusing to swear allegiance to the new government, Galvani lost his chair, was fired and died soon after. The second participant in the dispute, Volta, lived to see the full recognition of the discoveries of both scientists. In a historical dispute, both were right. The biologist Galvani entered the history of science as the founder of bioelectricity, the physicist Volta - as the founder of electrochemical current sources.

4. Experiments by VV Petrov. The beginning of electrodynamics

The work of the professor of physics of the Medico-Surgical Academy (now the Military Medical Academy named after S. M. Kirov in Leningrad), Academician V. V. Petrov ends the first stage of the science of "animal" and "metal" electricity.

The activities of V.V. Petrov had a huge impact on the development of science on the use of electricity in medicine and biology in our country. At the Medico-Surgical Academy, he created a physics cabinet equipped with excellent equipment. While working in it, Petrov built the world's first electrochemical source of high voltage electrical energy. Estimating the voltage of this source by the number of elements included in it, it can be assumed that the voltage reached 1800–2000 V at a power of about 27–30 W. This universal source allowed V. V. Petrov to conduct dozens of studies within a short period of time, which opened up various ways of using electricity in various fields. The name of V. V. Petrov is usually associated with the emergence of a new source of illumination, namely electric, based on the use of an effectively operating electric arc discovered by him. In 1803, V. V. Petrov presented the results of his research in the book "The News of Galvanic-Voltian Experiments". This is the first book on electricity published in our country. It was republished here in 1936.

In this book, not only electrical research is important, but also the results of studying the relationship and interaction of electric current with a living organism. Petrov showed that the human body is capable of electrification and that a galvanic-voltaic battery, consisting of a large number of elements, is dangerous for humans; in fact, he predicted the possibility of using electricity for physical therapy.

The influence of VV Petrov's research on the development of electrical engineering and medicine is great. His work "News of the Galvanic-Volta Experiments", translated into Latin, adorns, along with the Russian edition, the national libraries of many European countries. The electrophysical laboratory created by V.V. Petrov allowed the scientists of the Academy in the middle of the 19th century to widely expand research in the field of using electricity for treatment. The Military Medical Academy in this direction has taken a leading position not only among the institutions of our country, but also among European institutions. Suffice it to mention the names of professors V. P. Egorov, V. V. Lebedinsky, A. V. Lebedinsky, N. P. Khlopin, S. A. Lebedev.

What did the 19th century bring to the study of electricity? First of all, the monopoly of medicine and biology on electricity ended. Galvani, Volta, Petrov laid the foundation for this. The first half and the middle of the 19th century were marked by major discoveries in electrical engineering. These discoveries are associated with the names of the Dane Hans Oersted, the French Dominique Arago and Andre Ampère, the German Georg Ohm, the Englishman Michael Faraday, our compatriots Boris Jacobi, Emil Lenz and Pavel Schilling and many other scientists.

Let us briefly describe the most important of these discoveries, which are directly related to our topic. Oersted was the first to establish the complete relationship between electrical and magnetic phenomena. Experimenting with galvanic electricity (as electrical phenomena arising from electrochemical current sources were called at that time, in contrast to the phenomena caused by an electrostatic machine), Oersted discovered deviations of the needle of a magnetic compass located near an electric current source (galvanic battery) at the moment of short circuit and breaking the electrical circuit. He found that this deviation depends on the location of the magnetic compass. Oersted's great merit is that he himself appreciated the importance of the phenomenon he discovered. Seemingly unshakable for more than two hundred years, ideas based on the works of Gilbert about the independence of magnetic and electrical phenomena collapsed. Oersted received reliable experimental material, on the basis of which he writes, and then publishes the book "Experiments Relating to the Action of Electric Conflict on a Magnetic Needle". Briefly, he formulates his achievement as follows: "Galvanic electricity, going from north to south over a freely suspended magnetic needle, deflects its northern end to the east, and, passing in the same direction under the needle, deflects it to the west."

The French physicist André Ampère clearly and deeply revealed the meaning of Oersted's experiment, which is the first reliable proof of the relationship between magnetism and electricity. Ampère was a very versatile scientist, excellent in mathematics, fond of chemistry, botany and ancient literature. He was a great popularizer of scientific discoveries. Ampere's merits in the field of physics can be formulated as follows: he created a new section in the doctrine of electricity - electrodynamics, covering all manifestations of moving electricity. Ampère's source of moving electric charges was a galvanic battery. Closing the circuit, he received the movement of electric charges. Ampere showed that electric charges at rest (static electricity) do not act on a magnetic needle - they do not deflect it. In modern terms, Ampère was able to reveal the significance of transients (switching on an electrical circuit).

Michael Faraday completes the discoveries of Oersted and Ampere - creates a coherent logical doctrine of electrodynamics. At the same time, he owns a number of independent major discoveries, which undoubtedly had an important impact on the use of electricity and magnetism in medicine and biology. Michael Faraday was not a mathematician like Ampère; in his numerous publications he did not use a single analytic expression. The talent of an experimenter, conscientious and hardworking, allowed Faraday to compensate for the lack of mathematical analysis. Faraday discovers the law of induction. As he himself said: "I found a way to turn electricity into magnetism and vice versa." He discovers self-induction.

The completion of Faraday's largest research is the discovery of the laws of the passage of electric current through conductive liquids and the chemical decomposition of the latter, which occurs under the influence of electric current (the phenomenon of electrolysis). Faraday formulates the basic law in this way: "The amount of a substance located on conductive plates (electrodes) immersed in a liquid depends on the strength of the current and on the time of its passage: the greater the current strength and the longer it passes, the more the amount of substance will be released into the solution" .

Russia turned out to be one of the countries where the discoveries of Oersted, Arago, Ampere, and most importantly, Faraday found direct development and practical application. Boris Jacobi, using the discoveries of electrodynamics, creates the first ship with an electric motor. Emil Lenz owns a number of works of great practical interest in various fields of electrical engineering and physics. His name is usually associated with the discovery of the law of the thermal equivalent of electrical energy, called the Joule-Lenz law. In addition, Lenz established a law named after him. This ends the period of creating the foundations of electrodynamics.

1 The use of electricity in medicine and biology in the 19th century

P. N. Yablochkov, placing two coals in parallel, separated by a melting lubricant, creates an electric candle - a simple source of electric light that can illuminate a room for several hours. The Yablochkov candle lasted three or four years, finding application in almost all countries of the world. It was replaced by a more durable incandescent lamp. Electric generators are being created everywhere, and batteries are also becoming widespread. The areas of application of electricity are increasing.

The use of electricity in chemistry, which was initiated by M. Faraday, is also becoming popular. The movement of a substance - the movement of charge carriers - found one of its first applications in medicine for introducing the corresponding medicinal compounds into the human body. The essence of the method is as follows: gauze or any other tissue is impregnated with the desired medicinal compound, which serves as a gasket between the electrodes and the human body; it is located on the areas of the body to be treated. The electrodes are connected to a direct current source. The method of such administration of medicinal compounds, first used in the second half of the 19th century, is still widespread today. It is called electrophoresis or iontophoresis. The reader can learn about the practical application of electrophoresis in Chapter Five.

Another discovery of great importance for practical medicine followed in the field of electrical engineering. On August 22, 1879, the English scientist Crookes reported on his research on cathode rays, about which the following became known at that time:

When a high voltage current is passed through a tube with a very rarefied gas, a stream of particles escapes from the cathode, rushing at an enormous speed. 2. These particles move strictly in a straight line. 3. This radiant energy can produce mechanical action. For example, to rotate a small turntable placed in its path. 4. Radiant energy is deflected by a magnet. 5. In places where radiant matter falls, heat develops. If the cathode is given the shape of a concave mirror, then even such refractory alloys as, for example, an alloy of iridium and platinum, can be melted at the focus of this mirror. 6. Cathode rays - the flow of material bodies is less than an atom, namely particles of negative electricity.

These are the first steps in anticipation of a major new discovery made by Wilhelm Conrad Roentgen. Roentgen discovered a fundamentally different source of radiation, which he called X-rays (X-Ray). Later, these rays were called x-rays. Roentgen's message caused a sensation. In all countries, many laboratories began to reproduce Roentgen's setup, to repeat and develop his research. This discovery aroused particular interest among doctors.

Physical laboratories where the equipment used by Roentgen to receive X-rays were created were attacked by doctors, their patients, who suspected that they had swallowed needles, metal buttons, etc. in their bodies. The history of medicine had not known such a rapid practical implementation of discoveries in electricity, as happened with the new diagnostic tool - x-rays.

Interested in x-rays immediately and in Russia. There have not yet been official scientific publications, reviews on them, accurate data on the equipment, only a brief message about Roentgen's report appeared, and near St. Petersburg, in Kronstadt, the inventor of radio Alexander Stepanovich Popov is already starting to create the first domestic X-ray apparatus. Little is known about this. About the role of A. S. Popov in the development of the first domestic X-ray machines, their implementation, perhaps, for the first time became known from the book of F. Veitkov. It was very successfully supplemented by the inventor's daughter Ekaterina Alexandrovna Kyandskaya-Popova, who together with V. Tomat published the article "Inventor of radio and X-ray" in the journal "Science and Life" (1971, No. 8).

New advances in electrical engineering have accordingly expanded the possibilities for studying "animal" electricity. Matteuchi, using the galvanometer created by that time, proved that an electric potential arises during the life of a muscle. Cutting the muscle across the fibers, he connected it to one of the poles of the galvanometer, and connected the longitudinal surface of the muscle to the other pole and received a potential in the range of 10-80 mV. The value of the potential is determined by the type of muscles. According to Matteuchi, "biotok flows" from the longitudinal surface to the cross section and the cross section is electronegative. This curious fact was confirmed by experiments on various animals - tortoise, rabbit, rat and birds, carried out by a number of researchers, of which the German physiologists Dubois-Reymond, Herman and our compatriot V. Yu. Chagovets should be singled out. Peltier in 1834 published a work in which he presented the results of a study of the interaction of biopotentials with a direct current flowing through living tissue. It turned out that the polarity of biopotentials changes in this case. Amplitudes also change.

At the same time, changes in physiological functions were also observed. In the laboratories of physiologists, biologists, and physicians, electrical measuring instruments appear that have sufficient sensitivity and appropriate measurement limits. A large and versatile experimental material is being accumulated. This ends the prehistory of the use of electricity in medicine and the study of "animal" electricity.

The emergence of physical methods that provide primary bioinformation, the modern development of electrical measuring equipment, information theory, autometry and telemetry, the integration of measurements - this is what marks a new historical stage in the scientific, technical and biomedical areas of electricity use.

2 History of radiotherapy and diagnosis

At the end of the nineteenth century, very important discoveries were made. For the first time, a person could see with his own eye something hiding behind a barrier opaque to visible light. Konrad Roentgen discovered the so-called X-rays, which could penetrate optically opaque barriers and create shadow images of objects hidden behind them. The phenomenon of radioactivity was also discovered. Already in the 20th century, in 1905, Eindhoven proved the electrical activity of the heart. From that moment, electrocardiography began to develop.

Doctors began to receive more and more information about the state of the patient's internal organs, which they could not observe without the appropriate devices created by engineers based on the discoveries of physicists. Finally, doctors got the opportunity to observe the functioning of internal organs.

By the beginning of the Second World War, the leading physicists of the planet, even before the appearance of information about the fission of heavy atoms and the colossal release of energy in this case, came to the conclusion that it was possible to create artificial radioactive isotopes. The number of radioactive isotopes is not limited to naturally known radioactive elements. They are known for all chemical elements of the periodic table. Scientists were able to trace their chemical history without disturbing the course of the process under study.

Back in the twenties, attempts were made to use naturally radioactive isotopes from the radium family to determine the rate of blood flow in humans. But this kind of research was not widely used even for scientific purposes. Radioactive isotopes received wider use in medical research, including diagnostic ones, in the fifties after the creation of nuclear reactors, in which it was quite easy to obtain high activities of artificially radioactive isotopes.

The most famous example of one of the first uses of artificially radioactive isotopes is the use of iodine isotopes for thyroid research. The method made it possible to understand the cause of thyroid diseases (goiter) for certain areas of residence. An association has been shown between dietary iodine content and thyroid disease. As a result of these studies, you and I consume table salt, in which inactive iodine supplements are deliberately introduced.

In the beginning, to study the distribution of radionuclides in an organ, single scintillation detectors were used, which scanned the organ under study point by point, i.e. scanned it, moving along the meander line over the entire organ under study. Such a study was called scanning, and the devices used for this were called scanners (scanners). With the development of positionally sensitive detectors, which, in addition to the fact of registering a gamma quantum that fell, also determined the coordinate of its entry into the detector, it became possible to view the entire organ under study at once without moving the detector over it. At present, obtaining an image of the distribution of radionuclides in the organ under study is called scintigraphy. Although, generally speaking, the term scintigraphy was introduced in 1955 (Andrews et al.) and initially referred to scanning. Among systems with stationary detectors, the so-called gamma camera, first proposed by Anger in 1958, has received the most widespread use.

The gamma camera made it possible to significantly reduce the time of image acquisition and, in connection with this, to use shorter-lived radionuclides. The use of short-lived radionuclides significantly reduces the dose of radiation exposure to the body of the subject, which made it possible to increase the activity of radiopharmaceuticals administered to patients. At present, when using Ts-99t, the time of obtaining one image is a fraction of a second. Such short times for obtaining a single frame led to the emergence of dynamic scintigraphy, when a number of consecutive images of the organ under study are obtained during the study. An analysis of such a sequence makes it possible to determine the dynamics of changes in activity both in the organ as a whole and in its individual parts, i.e., there is a combination of dynamic and scintigraphic studies.

With the development of the technique for obtaining images of the distribution of radionuclides in the organ under study, the question arose about the methods for assessing the distribution of radiopharmaceuticals within the examined area, especially in dynamic scintigraphy. Scanograms were processed mainly visually, which became unacceptable with the development of dynamic scintigraphy. The main trouble was the impossibility of plotting curves reflecting the change in radiopharmaceutical activity in the organ under study or in its individual parts. Of course, a number of shortcomings of the resulting scintigrams can be noted - the presence of statistical noise, the impossibility of subtracting the background of surrounding organs and tissues, the impossibility of obtaining a summary image in dynamic scintigraphy based on a number of consecutive frames.

All this led to the emergence of computer-based digital processing systems for scintigrams. In 1969, Jinuma et al. used the capabilities of a computer to process scintigrams, which made it possible to obtain more reliable diagnostic information and in a much larger volume. In this regard, computer-based systems for collecting and processing scintigraphic information began to be very intensively introduced into the practice of the departments of radionuclide diagnostics. Such departments became the first practical medical departments in which computers were widely introduced.

The development of digital systems for collecting and processing scintigraphic information based on a computer laid the foundation for the principles and methods of processing medical diagnostic images, which were also used in the processing of images obtained using other medical and physical principles. This applies to X-ray images, images obtained in ultrasound diagnostics and, of course, to computed tomography. On the other hand, the development of computed tomography techniques led, in turn, to the creation of emission tomographs, both single-photon and positron. The development of high technologies for the use of radioactive isotopes in medical diagnostic studies and their increasing use in clinical practice led to the emergence of an independent medical discipline of radioisotope diagnostics, which was later called radionuclide diagnostics according to international standardization. A little later, the concept of nuclear medicine appeared, which combined the methods of using radionuclides, both for diagnosis and for therapy. With the development of radionuclide diagnostics in cardiology (in developed countries, up to 30% of the total number of radionuclide studies became cardiological), the term nuclear cardiology appeared.

Another extremely important group of studies using radionuclides is in vitro studies. This type of research does not involve the introduction of radionuclides into the patient's body, but uses radionuclide methods to determine the concentration of hormones, antibodies, drugs and other clinically important substances in blood or tissue samples. In addition, modern biochemistry, physiology and molecular biology cannot exist without the methods of radioactive tracers and radiometry.

In our country, the mass introduction of nuclear medicine methods into clinical practice began in the late 1950s after the order of the Minister of Health of the USSR (No. 248 of May 15, 1959) was issued on the establishment of radioisotope diagnostic departments in large oncological institutions and the construction of standard radiological buildings, some of them are still in operation. An important role was also played by the Decree of the Central Committee of the CPSU and the Council of Ministers of the USSR dated January 14, 1960 No. 58 "On measures to further improve medical care and protect the health of the population of the USSR", which provided for the widespread introduction of radiology methods into medical practice.

The rapid development of nuclear medicine in recent years has led to a shortage of radiologists and engineers who are specialists in the field of radionuclide diagnostics. The result of applying all radionuclide techniques depends on two important points: on the detecting system with sufficient sensitivity and resolution, on the one hand, and on the radiopharmaceutical preparation, which provides an acceptable level of accumulation in the desired organ or tissue, on the other hand. Therefore, every specialist in the field of nuclear medicine must have a deep understanding of the physical basis of radioactivity and detection systems, as well as knowledge of the chemistry of radiopharmaceuticals and the processes that determine their localization in certain organs and tissues. This monograph is not a simple review of achievements in the field of radionuclide diagnostics. It presents a lot of original material, which is the result of the research of its authors. Long-term experience of joint work of the team of developers of the department of radiological equipment of CJSC "VNIIMP-VITA", the Cancer Center of the Russian Academy of Medical Sciences, the Cardiology Research and Production Complex of the Ministry of Health of the Russian Federation, the Research Institute of Cardiology of the Tomsk Scientific Center of the Russian Academy of Medical Sciences, the Association of Medical Physicists of Russia made it possible to consider theoretical issues of radionuclide imaging, the practical implementation of such techniques and obtaining the most informative diagnostic results for clinical practice.

The development of medical technology in the field of radionuclide diagnostics is inextricably linked with the name of Sergei Dmitrievich Kalashnikov, who worked in this direction for many years at the All-Union Scientific Research Institute of Medical Instrumentation and supervised the creation of the first Russian tomographic gamma camera GKS-301.

5. A Brief History of Ultrasound Therapy

Ultrasonic technology began to develop during the First World War. It was then, in 1914, when testing a new ultrasonic emitter in a large laboratory aquarium, the outstanding French experimental physicist Paul Langevin discovered that the fish, when exposed to ultrasound, became worried, swept about, then calmed down, but after a while they began to die. Thus, by chance, the first experiment was carried out, from which the study of the biological effect of ultrasound began. At the end of the 20s of the XX century. The first attempts were made to use ultrasound in medicine. And in 1928, German doctors already used ultrasound to treat ear diseases in humans. In 1934, the Soviet otolaryngologist E.I. Anokhrienko introduced the ultrasound method into therapeutic practice and was the first in the world to carry out combined treatment with ultrasound and electric current. Soon, ultrasound became widely used in physiotherapy, quickly gaining fame as a very effective tool. Before applying ultrasound to treat human diseases, its effect was carefully tested on animals, but new methods came to practical veterinary medicine only after they were widely used in medicine. The first ultrasound machines were very expensive. The price, of course, does not matter when it comes to people's health, but in agricultural production this must be taken into account, since it should not be unprofitable. The first ultrasonic treatment methods were based on purely empirical observations, however, in parallel with the development of ultrasonic physiotherapy, studies of the mechanisms of the biological action of ultrasound were developed. Their results made it possible to make adjustments to the practice of using ultrasound. In the 1940-1950s, for example, it was believed that ultrasound with an intensity of up to 5 ... 6 W / sq. cm or even up to 10 W / sq. cm is effective for therapeutic purposes. Soon, however, the intensities of ultrasound used in medicine and veterinary medicine began to decrease. So in the 60s of the twentieth century. the maximum intensity of ultrasound generated by physiotherapy devices has decreased to 2...3 W/sq.cm, and currently produced devices emit ultrasound with an intensity not exceeding 1 W/sq.cm. But today, in medical and veterinary physiotherapy, ultrasound with an intensity of 0.05-0.5 W / sq. cm is most often used.

Conclusion

Of course, I was not able to cover the history of the development of medical physics in full, because otherwise I would have to tell about each physical discovery in detail. But still, I indicated the main stages in the development of honey. physicists: its origins do not originate in the 20th century, as many believe, but much earlier, in ancient times. Today, the discoveries of that time will seem trifles to us, but in fact for that period it was an undoubted breakthrough in development.

It is difficult to overestimate the contribution of physicists to the development of medicine. Take Leonardo da Vinci, who described the mechanics of joint movements. If you objectively look at his research, you can understand that the modern science of the joints includes the vast majority of his works. Or Harvey, who first proved the closure of blood circulation. Therefore, it seems to me that we should appreciate the contribution of physicists to the development of medicine.

List of used literature

1. "Fundamentals of the interaction of ultrasound with biological objects." Ultrasound in medicine, veterinary medicine and experimental biology. (Authors: Akopyan V.B., Ershov Yu.A., edited by Shchukin S.I., 2005)

Equipment and methods of radionuclide diagnostics in medicine. Kalantarov K.D., Kalashnikov S.D., Kostylev V.A. and others, ed. Viktorova V.A.

Kharlamov I.F. Pedagogy. - M.: Gardariki, 1999. - 520 s; page 391

Electricity and man; Manoilov V.E. ; Energoatomizdat 1998, pp. 75-92

Cherednichenko T.V. Music in the history of culture. - Dolgoprudny: Allegro-press, 1994. p. 200

Everyday Life of Ancient Rome Through the Lens of Pleasure, Jean-Noel Robber, The Young Guard, 2006, p. 61

Plato. Dialogues; Thought, 1986, p. 693

Descartes R. Works: In 2 vols. - Vol. 1. - M .: Thought, 1989. Pp. 280, 278

Plato. Dialogues - Timaeus; Thought, 1986, p. 1085

Leonardo da Vinci. Selected works. In 2 vols. T.1. / Reprint from ed. 1935 - M.: Ladomir, 1995.

Aristotle. Works in four volumes. T.1.Ed.V. F. Asmus. M.,<Мысль>, 1976, pp. 444, 441

List of Internet resources:

Sound Therapy - Nag-Cho http://tanadug.ru/tibetan-medicine/healing/sound-healing

(date of treatment 18.09.12)

History of phototherapy - http://www.argo-shop.com.ua/article-172.html (accessed 21.09.12)

Fire treatment - http://newagejournal.info/lechenie-ognem-ili-moksaterapia/ (accessed 21.09.12)

Oriental medicine - (date of access 22.09.12)://arenda-ceragem.narod2.ru/eto_nuzhno_znat/vostochnaya_meditsina_vse_luchshee_lyudyam

Medical Physics Podkolzina Vera Alexandrovna

1. Medical physics. Short story

Medical physics is the science of a system that consists of physical devices and radiation, medical and diagnostic devices and technologies.

The goal of medical physics is to study these systems for the prevention and diagnosis of diseases, as well as the treatment of patients using the methods and means of physics, mathematics and technology. The nature of diseases and the mechanism of recovery in many cases have a biophysical explanation.

Medical physicists are directly involved in the treatment and diagnostic process, combining physical and medical knowledge, sharing responsibility for the patient with the doctor.

The development of medicine and physics have always been closely intertwined. Even in ancient times, medicine used physical factors for medicinal purposes, such as heat, cold, sound, light, various mechanical effects (Hippocrates, Avicenna, etc.).

The first medical physicist was Leonardo da Vinci (five centuries ago), who conducted research on the mechanics of movement of the human body. Medicine and physics began to interact most fruitfully from the end of the 18th - beginning of the 19th centuries, when electricity and electromagnetic waves were discovered, that is, with the advent of the era of electricity.

Let's name a few names of great scientists who made the most important discoveries in different eras.

The end of the 19th - the middle of the 20th centuries. associated with the discovery of x-rays, radioactivity, theories of the structure of the atom, electromagnetic radiation. These discoveries are associated with the names of V.K. Roentgen, A. Becquerel,

M. Skladovskoy-Curie, D. Thomson, M. Planck, N. Bohr, A. Einstein, E. Rutherford. Medical physics really began to establish itself as an independent science and profession only in the second half of the 20th century. with the advent of the atomic age. In medicine, radiodiagnostic gamma devices, electronic and proton accelerators, radiodiagnostic gamma cameras, X-ray computed tomographs and others, hyperthermia and magnetotherapy, laser, ultrasound and other medical-physical technologies and devices have become widely used. Medical physics has many sections and names: medical radiation physics, clinical physics, oncological physics, therapeutic and diagnostic physics.

The most important event in the field of medical examination can be considered the creation of computed tomographs, which expanded the study of almost all organs and systems of the human body. OCT has been installed in clinics all over the world, and a large number of physicists, engineers and doctors have worked to improve the technique and methods to bring it almost to the limits of what is possible. The development of radionuclide diagnostics is a combination of radiopharmaceutical methods and physical methods for recording ionizing radiation. Positron emission tomography imaging was invented in 1951 and published in the work of L. Renn.