Natural modeling of the processes occurring during a gunshot wound or mine-explosive injury uses two types of simulators: biological and non-biological nature. Objects of biological origin are, first of all, human corpses, their separate parts, as well as various types of mammals. Non-biological include soap and gelatin blocks, iron sheets, various types of clothing fabrics, etc. Of course, "shooting" corpses and animals for scientific purposes ultimately yields the most valuable theoretical results, but here are ethical considerations … In addition, the requirements for scientific reproducibility of results should put an end to shooting at cadaveric material in the future. The fact is that the tissues of each person have their own unique parameters - the proportion of adipose tissue, density, amount of fluid, and so on. For example, the results of ballistic tests on the corpses of women and men (biomanikins) sometimes give completely different results due to a different ratio of muscle and adipose tissue. It also makes adjustments to the use of rigor mortis, which alters the mechanical properties of tissues. Simply put, you need to shoot a corpse immediately after death. It is impossible to use corpses to study physiological responses to "firearms". Therefore, in modern times, a significant arsenal of nonbiological simulators has been created, the parameters of which are similar for human tissues and organs. However, living imitators still have a place in wound ballistics.
In the history of wound ballistics, pigs, horses, calves, bulls, goats, sheep, dogs and small animals - cats and rabbits - were also used as biological objects. The man very coolly approached the choice of potential victims of science: the unfortunate should be non-aggressive, easy to observe, unpretentious in maintenance and inexpensive. Horses and cattle were among the first to be shot by bullets due to their massive muscle mass, which makes it possible to obtain a long wound channel, which is very convenient for research. Over time, it turned out that working with such large animals is inconvenient and expensive. With horses, another problem emerged - due to the low standing of the dome of the diaphragm and the severity of the internal organs in animals in the supine position, compression of the lower lobes of the lungs occurs with the development of hypoxia. In this regard, general anesthesia is required for more than 30 minutes with the use of expensive and complex equipment. The complex digestive system of horses and bulls, which, in an unconscious state, can unexpectedly ruin the whole experiment, also adds complications. The overly thick skin of these animals makes it necessary to amend the results of the tests. They are not bad for experiments on wound ballistics of goats and sheep - “human” systems of anesthesia and medications are quite suitable for them. A developed coat and a pronounced difference in the location of internal organs complicate the assessment of damage somewhat. But the dog was generally awarded the honorary title of the protagonist of experimental medicine, and wound ballistics is no exception here.
Monument to Pavlov's dog. Source: Wolcha.ru
They are well trained and obedient enough to carry out successful work on experimental treatment of gunshot wounds. Arteries and veins in dogs are easily accessible for puncture and injection. General medical anesthesia and standard equipment such as endotracheal tubes and ventilators are excellent for canines. In general, the dog is the best friend of the wound ballistics specialist? Not really. Very thin skin, weakly connected to the underlying tissues, when hit by a bullet, is torn into pieces of a large area with the formation of deep pockets. This is not typical of human skin, so the accuracy of the experiments suffers. In addition, if a large muscle mass is required for the study, one has to look for large dogs weighing more than 40 kilograms, which is also problematic. Pigs came to the aid of the dog in such a difficult matter, surprisingly similar to the human body not only in structure, but even in biochemistry. This is actively used by transplantologists and other medical experimenters. But these animals, unlike dogs, are reluctant to give themselves up for blood sampling or anesthesia, in general, behave in this sense like true pigs. There are difficulties with artificial ventilation of the lungs - a tendency to spasm of the larynx can block tracheal intubation. It is very good to examine the external picture of gunshot wounds in pigs with a detailed assessment of the inlets and outlets.
The location of the obstacle and the animal before the experiment to study the lethal effect of the ricochet bullet. Source: Bulletin of the Russian Military Medical Academy
How are firearms tested on animals? Until the experiment, the animals are observed in the vivarium for 5-7 days, and immediately before the "X hour" the unfortunates are immersed in anesthesia and fixed. The criterion for the level of anesthesia is a decrease in reflexes and tone of skeletal muscles. They shoot at animals with bullets at reduced and actual ranges. The weapon is placed 8-10 meters from the animal (the bullet has time to stabilize), but the gunpowder is added exactly as much as needed to accelerate the bullet to the required speed. Less gunpowder - less bullet speed, respectively, the investigated range will be greater. The difficulty with the real range is that it is very difficult to get precisely from a distance of, for example, 500 meters into a live target. And an exact hit exactly at the specified point on the victim's body is a prerequisite for high-speed video filming and pulsed radiography.
The pig is under anesthesia and with connected recording equipment. Source: Bulletin of the Russian Military Medical Academy
The appearance of the entrance bullet holes when injured by fragments of a bullet cartridge SP10. Source: Bulletin of the Russian Military Medical Academy
At the same time, it is the actual range that gives the most realistic results - the bullet retains its natural conditions of movement. In the case of a fatal wound, a full cycle of examination is carried out, followed by an autopsy. For non-fatal wounds, behavioral activity and the entire spectrum of physiological functions are investigated - from the state of the nervous system to the tone of peripheral vessels.
A picture of the injury of the experimental animal after overcoming a solid barrier by a bullet. Source: Military Medical Journal.
On the question of ethics. In 1959, English researchers Russell and Birch proposed the concept of "three Rs" ("The three Rs"), which should be adhered to when conducting any traumatic experiments with animals. Three components: replacement - replacement, reduction - reduction and refinement - increase in quality. The principle of substitution requires, if possible, to replace animals with other models and methods (mathematical, for example), and instead of mammals to use animals with a less developed nervous system. The principle of reduction assumes the use of as few animals as possible in "inhuman" experiments. The third principle, quality improvement, requires the use of as high-tech equipment and medicines for anesthesia as possible. It is also necessary to take animals out of the experiment as painlessly as possible. Much of the responsibility for following these guidelines rests with the ethics committees. For example, at the Military Medical Academy. S. M. Kirov has an independent ethics council, which, among other things, monitors the use of laboratory animals in biomedical experiments.
Currently, neither in Russia nor in the world experts on wound ballistics of firearms can not refuse the use of animals and cadaveric material, even taking into account the wide variety of simulators of non-biological origin.
