It is believed that the occurrence of ischemic diseases is not only the disorder and obstacle of blood flow, but also the disorder and obstacle of oxygen transport, which is considered to be the main cause of ischemic diseases at present. Therefore, to judge the curative effect of any therapy used to treat ischemic diseases, the main criterion should be whether the disorder and obstacle of oxygen transmission can be corrected and improved, and whether the oxygen transmission ability of blood can be restored and improved.
Theory of human function regulation
It holds that the human body is an organic and open giant system, and the physiological functions of the human body are not only influenced by the communication and adjustment between the functional systems in the body, but also by external substances, energy and information. The instrument takes laser (sometimes accompanied by oxygen inhalation) as external factors, stimulates the body fluid system (including blood, lymph and saliva), nervous system and meridian system, and can effectively regulate the functions of human tissues and organs and the whole body, which embodies this theory.
Laser biology theory
It is considered that irradiating the body with weak laser with appropriate wavelength and certain power density can cause the reaction of the body, that is, the biological effects of laser, such as biological stimulation effect and photochemical effect, and then these biological effects can be used to treat diseases and protect health. These effects have certain rules, and parameters are selected and set according to these, so as to ensure the effect of treatment and health care. If you have ischemic and hypoxic diseases, you should go to the hospital for treatment in time to ensure that the condition is controlled and improved. However, because the treatment and rehabilitation of such diseases need a long course of treatment, most patients cannot be hospitalized for a long time, and it is not appropriate to take drugs for a long time. Some patients often relapse after a period of time after their condition is controlled and improved, so they need repeated treatment or even lifelong medication. With the laser therapeutic instrument, patients can get auxiliary treatment and long-term care at home, thus consolidating and improving the curative effect, further alleviating the illness, promoting rehabilitation, reducing medication, avoiding the toxic and side effects of drugs, enhancing immunity and preventing the recurrence of diseases. If the instrument is used for nursing when symptoms appear, the deterioration of the disease can be controlled in time, the pathological process can be reversed and the effect of self-rehabilitation can be achieved. Laser therapeutic instrument is a widely used health care method for middle-aged and elderly people. Middle-aged and elderly people in sub-health state can adjust blood lipid, blood sugar and blood pressure, restore normal physiological function and improve immune function, thus preventing the occurrence of ischemic and hypoxic diseases. For ordinary middle-aged and elderly people, it has the effects of delaying aging, promoting digestion, strengthening the body, calming the nerves and helping sleep.
Special biological effects of laser
Laser biological effects can generally be divided into thermal effects and non-thermal effects. The thermal effect is mainly caused by the thermal solidification and denaturation of tissues, and it will be intensified with the increase of incident light and temperature. In severe cases, local biological tissues may be burnt, carbonized, vaporized and evaporated. From the perspective of histopathology, this is a process of burn coagulation and local biological tissue necrosis. Non-thermal effect is mainly mechanical damage, which has a series of nonlinear effects such as photochemistry and ionization.
It is generally believed that the biological effects of laser include thermal effect, pressure effect, photochemical effect, electromagnetic field effect and biological stimulation effect. These five effects are the mechanism of laser biological effect.
heat effect
It is mainly the effect caused by laser irradiation in visible and infrared bands. When laser irradiates biological tissue, the photon energy of laser is absorbed by the molecules of biological tissue, and the absorbed light energy intensifies the vibration and rotation of biological molecules themselves, and also intensifies the collision between these excited molecules and surrounding molecules. The intensification of molecular movement makes the irradiated local tissue gradually warm up, which shows the form of temperature increase. In particular, tissues and cells contain various pigments (melanin, hemoglobin, carotene, etc. ), which increases the absorption of light energy and promotes the degradation of biological tissues, especially the degradation of protein, so that tissues and cells are damaged to varying degrees (macro, micro or functional).
Under the action of laser, some endothermic chemical reactions may be initiated, which are called thermochemical reactions. There are various thermochemical reactions in living things. One of the characteristics of thermochemical reaction is that its reaction rate increases with the increase of temperature, because the increase of temperature can increase the collision frequency and molecular energy, and the activation energy of photochemical reaction comes from the absorption of photon energy, not from collision, so the photochemical reaction rate is almost independent of temperature. Another difference between photochemical reaction and thermochemical reaction is that photochemical reaction can produce other excited atoms, molecules and free radicals, which are impossible to produce during thermochemical reaction. But in fact, photochemical reaction and thermal reaction are not easy to distinguish. Because the primary reaction of chemical reaction may be photochemical reaction, and the secondary reaction is thermochemical reaction. The thermal effect of laser on tissue has its general law:
The temperature rise of (1) structure will increase with the increase of laser energy;
(2) The infrared laser has high thermal efficiency;
(3) The higher the light absorption rate of biological tissues, the more heat is generated;
(4) Biological tissues with small specific heat and heat capacity (i.e. water content) produce heat quickly;
(5) The higher the blood flow and thermal conductivity of biological tissues, the slower the heat production.
As far as the local temperature of irradiated tissue is concerned, the influence on biological tissue is different because of the different temperature rise. For example, when laser irradiates skin and mucous membrane, it will change in different degrees because of different temperature rise. Low-intensity laser only increases the local tissue temperature by 1 ~ 2℃, which makes the local tissue feel warm. This temperature will never cause heat-induced damage, but mainly cause photochemical changes, which will cause a series of physiological and biochemical changes in the body and regulate the body's functions to achieve therapeutic purposes. He-Ne laser and semiconductor laser are commonly used for local irradiation, acupoint irradiation, reflection zone irradiation, laser intravascular irradiation and nasal mucosa irradiation in clinic.
1 ~ 2mW He-Ne laser or semiconductor laser irradiation can increase the average temperature of the irradiated area by 0.05 ~ 0. 1℃. For example, the local temperature will increase by 65438 0.5 ~ 5℃ after 5 minutes of Xiang Ying and buccal irradiation. During intravascular He-Ne laser irradiation, patients sometimes consciously feel warm at the irradiated site, indicating mild fever, which can activate intravascular enzymes and receptors and cause a series of physiological and biochemical changes in the body. During intranasal irradiation, some patients feel dry nasal cavity, and some even can't persist. This is because the nasal cavity is closed, heat is not easy to escape, and water evaporates, so it is necessary to adjust the dose or shorten the action time.
(2) Pressure effect
When biological tissue is irradiated by laser, the pressure generated by photons hitting its surface is called light pressure.
It is generally believed that the lasers that form pressure are mainly pulsed, Q-switched and mode-locked lasers. When ordinary light irradiates an organism, the radiation pressure formed by the collision of photons on its surface is very small and can be ignored. The light pressure (self-light pressure) of laser is very low, but the power is also enhanced to some extent when focusing light.
If the pulse frequency is 8 ~ 13Hz and the rapid sleep (REM) frequency is the same, the treatment effect may be better, and the normal REM can live longer.
(3) photochemical effect
When a molecule absorbs a photon, it will rise to the excited state of an electron, thus starting a series of processes in which the excited molecule returns to the initial ground state and its energy is continuously reduced. In this process, in addition to radiation and non-radiation (so-called photophysics), excited molecules can also undergo several chemical reactions of bond breaking and bond forming, that is, the process in which old bonds are completely destroyed or new bonds are formed, which is called photochemical reaction. Simply put, photochemical reaction is a chemical reaction that uses light energy as activation energy, which is called photochemical reaction.
Laser chemical effects mainly occur in ultraviolet band, and a few occur in blue-green band, which is determined by the spectral absorption characteristics of biological macromolecules. The spectral absorption peaks of purine, pyrimidine nucleotide, nucleic acid, vitamin A, vitamin B, vitamin D, vitamin E, riboflavin, amino acid and polypeptide protein are all in the wavelength range of 260 37 1 nm, while the main spectral absorption peaks of cytochrome A, B, C, reduced hemoglobin, oxidase, carotene, melanoid and rhodopsin are important for biological tissues. For example, the isomerization of rhodopsin in retina, the production of vitamin D by skin under ultraviolet irradiation, the photosynthesis of plant chlorophyll and so on. According to the experimental results in vitro, photochemical reactions can be divided into several types: ① photopolymerization; ② substitution reaction; ③ photolysis; ④ Photooxidation, photoisomerization and photosensitization. The photochemical effect produced by over-dose laser irradiation can damage fonts, and the molecular bond vibration effect can break DNA bonds.
When laser is irradiated, its energy can't reach to destroy biological tissue. When thermal effect and pressure effect are not dominant, it may be mainly photochemical effect in biological tissue.
Most cells are insensitive to visible light because their organic components have no obvious absorption of visible light. However, some organelle macromolecules can selectively absorb these photosensitizers if they exist and enrich in biological tissues and cells. After laser irradiation, photosensitizer molecules absorb light energy, causing photochemical reactions, destroying organelles and even killing cells. Therefore, drugs, especially photosensitive drugs, must be used with caution when low-intensity laser blood is irradiated. Photosensitizers have no permanent chemical reaction, but only catalyze photochemical reactions.
In phototherapy, it can be divided into two categories, one is psoralen without oxygen molecules. It is an efficient photosensitizer, and the temperature has little effect on the photosensitization reaction rate. Psoralea corylifolia tincture and other drugs are applied to the focus, and then irradiated by ultraviolet nitrogen laser and excimer laser, which can treat psoriasis and vitiligo. If there is furanilic acid, 365nm ultraviolet radiation can kill bacteria quickly.
Another kind of phototherapy is photodynamic therapy which requires the participation of oxygen molecules. The prerequisite of this phototherapy method is light with a specific wavelength, photosensitive substances and molecular oxygen, and the key in the reaction process is the formation of singlet oxygen. Hematoporphyrin derivatives are the most commonly used photosensitizers at present. Three days after intravenous injection of hematoporphyrin derivatives, cancer patients were irradiated with 630nm dye laser, which destroyed the vascular tissue and cancer tissue supplying the tumor due to photosensitive effect, resulting in cancer cell death. This method has been widely used in the treatment of body surface tumors and intracavitary tumors (gastric cancer, lung cancer and rectal cancer) at home and abroad, and the effective rate can reach 80.6%. In addition to cancer, this method can also be used to treat nevus flammeus, psoriasis and so on, and has achieved good results. Besides hematoporphyrin derivatives, many new photosensitizers are also used in clinic, such as hypocrellin, phellodendron amurense and coptis chinensis, all of which are used to treat viral keratitis, vulvar leukoplakia, age-related macular degeneration and even acquired immunodeficiency syndrome (AIDS).
In addition to treatment, patients can be injected with some fluorescent drugs, and then locally irradiated with ultraviolet laser or blue, purple and green laser to make them emit specific fluorescence in malignant tumors but not in normal tissues, which is very helpful for early diagnosis and early detection of cancer. For example, after injection of fluorescein sodium, helium-cadmium laser irradiation of cervical cancer can show purple grape fluorescence, and irradiation of gastric cancer can show yellow-green fluorescence. For example, after injection of hematoporphyrin derivative, it can show orange fluorescence in tumor by krypton molecular laser or argon ion laser irradiation. This method of cancer diagnosis can also display fluorescence for precancerous lesions and five kinds of cancer cells, so it can diagnose tumors early, and its diagnostic coincidence rate can reach 88%.
(4) electromagnetic effect
Laser wave belongs to electromagnetic wave, which will produce electromagnetic effect when interacting with biological substances. The intensity of electromagnetic field depends on the irradiation energy.
Because the output power of low-intensity laser is very small, it has little influence on electromagnetic effect. However, even when low-intensity laser interacts with organisms, the electric field intensity generated is about 50 times greater than that generated by the strongest sunlight on the ground. Its electromagnetic force can change the conformation of cell membrane, including membrane receptor, membrane surface charge, membrane lipid bilayer, membrane protein and so on. Increase the negative charge on the membrane surface, reduce the aggregation of red blood cells and platelets, slow down the erythrocyte sedimentation rate and reduce the blood viscosity.
(E) Biological stimulation effect
The above three effects all consider the thermal, mechanical and chemical effects of a certain intensity of laser under a certain mechanism, which will cause damage to tissues and cells. However, under the irradiation of low-intensity laser, biological tissue will be stimulated by laser irradiation, which will cause microscopic physiological changes of the body. The body tissue will not be damaged, but it can also promote the recovery of the focus tissue to the normal state, which has been reported in animal experiments and clinical treatment.