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.

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.

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.

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.

This article is to review the basic principles of renal perfusion in CT and MR,imaging method and perfusion characteristics in kidney diseases.It shows that in addition to the morphologic information,perfusion imaging can also provide functional and metabolic information about the renal neoplasms,which is very helpful for not only the differential diagnosis,but also the evaluation of tumor biological behaviors,it will have a bright future in clinical application.

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: To evaluate the electron beam computed tomography(EBCT) three-dimensional reconstruction in the diagnosis of bowel obstruction.Methods: Seventy-eight patients suspected of bowel obstruction underwent EBCT with two-phase enhancement scanning and 32 of them were re-established by corona-MPR and sagittal-MPR.All the EBCT results were analyzed and compared with the clinical findings.Results: Seventy-three of the cases were diagnosed as bowel obstruction by EBCT,which were all confirmed by surgery or follow-up,with an accuracy rate of 100% for location diagnosis and 86.3% for etiology.Conclusion: EBCT 3D-reconstruction has great advantages in determining the location,etiology and blood-supply of bowel obstruction.

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.