The principal and technique of laser therapy are discoursed upon in chief, current development and application of laser therapy equipment are described by introducing some lasers applied in surgery and medicine such as ophthalmology and photodynamic therapy. Finally, individual view to evolution trend of laser therapy equipment is presented.

Low-level laser biostimulation can be applied in wound therapy to speed up the wound healing,prevent infection and relieve the pain.Although it is still a problem how to select the laser wavelength,power and dose for different wounds because of its unclear mechanism,it has been proved that LLLT has good curative effect and application prospect in wound healing.

BACKGROUND: Transmitting law of laser in biological tissues is hard to calculate by mathematical analysis or clinical monitoring. Therefore, numerical simulation is commonly used for its prediction. Monte Carlo simulation is an ideal method for this study. OBJECTIVE: To establish a light dose mathematical model by Monte Carlo method, and to explore the damage of laser to liver tissues.METHODS: Light dose mathematical models of normal tissues and tumor with varied optical parameters were established by Monte Carlo method, and the migration trajectory of ponderosus photons was calculated one by one, and the distribution of photon was analyzed.RESULTS AND CONCLUSION: The decay of photo dose with depth was approximately exponential, and the second peak value will be formed at the verge of the organization. The damage of organization was a process of the threshold value. The dose curved shape was the same as the line of threshold. Using Monte Carlo method, the ransmitting law of laser in tissues of liver tumor was obtained. The results demonstrated that optimal ration of illumination intensity can obtain a shallow but entirely selective depth of tumor necrosis, but to obtain deeper tumor necrosis necessarily means some degree of normal tissue damage.

Malnutrition is the common complication for the patients with gastrointestinal neoplasms during perioperative period.Tumor and chemotherapy drugs are the main influencing factors of patients with malnutrition.The correct evaluation of the nutritional status in patients is the basis of individualized nutrition therapy.New evaluation methods and nutritional preparations could more help patients with gastrointestinal neoplasms during perioperative period to maintaining good nutritional status.

Repair of peripheral nerve injury is an important topic in the field of neural tissue rehabilitation research.At present there are many new technologies that can realize the treatment of peripheral nerve injury.As the research on the effect of laser radiation on biological mechanism develops,a new method for tissue regeneration is applied to the field of nerve injury repair.This paper is mainly centered on the recovery mechanism of low-level laser radiation,the function recovery after peripheral nerve injury and nerve tissue scarring inhibition.The new progress of laser treatment and nerve injury repair are reviewed.

Laser has been used in the treatment of glaucoma for more than twenty years.Its main applications include laser peripheral iridoplasty,laser trabeculoplasty,laser sclerostomy,and laser cyclophotocoagulation. Other applications such as C02 laser filtering surgery and photodynamic therapy(PDT)have just started.In this paper,a review is provided on the present applications of lasers in the treatment of glaucoma including choice of laser,indications,surgery approach and efficacy.The prospect of the future application is also discussed.

Nanotechnology is a newly rising subject.In order to reflect achievements and developments of nanotechnology,applications of nanotechnology to modern medicine are summarized,and its influences were analyzed dialectically.Nanotechnology will evoke a novel technical revolution,although there is still a long way to go before it is widely used.

Objective Turn the CT sectional image into three-dimensional imaging based on VTK, in or-der to make better treatment programs for patients with liver cancer. Methods Establish visualization toolkit (VTK) visualization development environment based on VC6.0, obtain patient's CT images in DICOM format, use VTK filter and Laplacian sharpening template for pre-treatment of the images, and then use Ray-Casting algo-rithm for three-dimensional reconstruction. Results We can get three-dimensional images with higher resolu-tion and faster imaging speed through this method, which can also be cut, rotated and zoomed. Conclusion Ray-Casting algorithm based on VTK can be used for the three-dimensional imaging of human liver. With the as-sistance of three-dimensional images, doctors can detect the location of diseased tissue more easily and observe the shapes of diseased tissue intuitively.

Objective We discussed the optimal method for intestinal preparation before colonoscopy examination in order to increase the success rate of intestinal examination and reduce the incidence of adverse effect. Methods We divided 120 patients who were to undergo colonoscopy examination into group A, B and C with 40 cases in each group. Group A received oral magensium sulfate 100ml and 6000ml water after that on the morning of the examination. Group B received oral magensium sulfate 50ml and 2000ml in the evening before the examination, oral magensium sulfate 50ml and 400ml water on the morning of the examination. Group C was given oral magensium sulfate 100ml and 4000～5000 water at the same time. Group A and B took part in appropriate activity and were given health education. The effect of intestinal preparation was compared between the three groups. Results The cleaning degree of group B was better than those of the other two groups (P<0.05). The adverse effect of group B was less than that of group C (P<0.01). Conclusions Oral intake of magensium sulfate in the evening before and on the morning of the examination for intestinal preparation could increase the cleaning degree of intestine, facilitate the observation of disease part and lessen adverse effect. It gave satisfying examination results and made patients satisfied.

Objective To study the early resuscitation with intravenous administration of liquor in uncontrolled hemorrhagic shock model by four-staged abdominal aorta injury in rats in order to settle the controversy over the issue of volume resuscitation.Method Forty Sprague-Dawley rats were canulated with catheters into the left ventricle,femoral artery and femoral vein,respectively.Animals were subjected to vaseular injury of infrarenal pierced with a 25G needle leading to uncontrolled hemorrhagic shock.After aorta injury,the models were processed into 4 stages:early injured stage,early rescue stage,delayed rescue stage and observation stage.The rescue with rapid infusion of 45 ml/kg lactated Ringer's solution in 15 minutes in the early stage and the followed rescue in the late stage;and(4)sham-rescued.The MAP,CVP,lactic acid and Hct were monitored.The volume of blood loss and the survival time of rats were recorded too.Results After aorta injury,The MAP dropped from 94.3 mmHg to 25.8 mmHg and rised quickly after early resuscitation with rapid infusion of liquor and then again fell soon,and CVP did likewise.Lactic acid was increased and reached 3-4 times of baseline at 4 h in all group except Sham-resuced group.The Hct levels decreased quickly after resuscitation with liquor in early rescue stage and delayed rescue stage.The blood loss in abdomen increased after rapid infusion of lactated Ringer's solution in early rescue stage(blood loss increased from 22.8 ml/kg to 27.7ml/kg,P＜0.05).There Was no significant difference in mortality between those groups.Conclusions Rapid volume resuscitation at early stage of abdominal aorta injured with uncontrolled hemorrhagic shock cannot increase the circulatory blood volume for maintaining stable blood pressure norminimize the elevation of blood lactic acid.On the contrary,resuscitation with rapid administration of liquor at early stage can enhance blood loss and decrease the level of Hct.The survival time and survival rate can't be increased by early rescue with rapid liquor infusion.