Dentistry ; Photography ; instrumentation

Modern photo-mechanics testing techniques are widely used in industrial circles and academic circles. In order to solve the problem of biomedical engineering, shadow moiré method is used in oral and dental area in our study. A molar tooth was tested by phase shift shadow moiré method. Through testing molar tooth, the results show that shadow moiré method could be used for measuring the appearance of the oral area and concave and convex parts of molar tooth could also be distinguished and shown by interference patterns. The characteristics of shadow moirh are that it does't need exerting load on the specimen and could realize non-contact measurement.
Cephalometry ; methods ; Humans ; Moire Topography ; instrumentation ; statistics & numerical data ; Molar ; anatomy & histology ; Photography

In sport games, since the human body movement data are mainly drawn from the sports field with the hues or even interruptions of commercial environment, some difficulties must be surmounted in order to analyze the images. It is obviously not enough just to use the method of grey-image treatment. We have applied the characteristics of the prime number function to the human body movement images and thus introduce a new method of image processing in this article. When trying to deal with certain moving images, we can get a better result.
Computer Graphics ; Humans ; Mathematics ; Models, Theoretical ; Phantoms, Imaging ; Photography ; instrumentation ; methods ; Signal Processing, Computer-Assisted ; Sports

Photo refractive keratectomy (PRK) and laser Situ Keratomileusis (LASIK) have been used for over a decade and become popular in China. Principles and characteristics of eye trackers made by several famous foreign manufacturers are introduced in this paper and their developing direction in the future is pointed out too.
Cornea ; surgery ; Eye Movements ; Humans ; Keratomileusis, Laser In Situ ; instrumentation ; Lasers, Excimer ; Myopia ; surgery ; Photography ; instrumentation ; methods ; Photorefractive Keratectomy ; instrumentation ; Refractive Surgical Procedures ; Video Recording

PURPOSE: To investigate the effect of lens density on liquefaction time by using liquefaction device (AquaLase(R), Alcon Laboratories, TX, U.S.A.). METHODS: Cataract surgery using AquaLase(R) was performed on 47 eyes. With a Scheimpflug camera, the density and thickness of lens were measured in eye of each patient preoperatively. During surgery, liquefaction time and total number of pulses were recorded. The correlation of both density and thickness of lens with liquefaction time and total number of pulses was analyzed. RESULTS: The mean density of anterior cortex, nucleus, and posterior cortex was 112.45+/-42.1 computer compatible tapes (CCT), 76.5+/-22.7 CCT, and 70.9+/-52.2 CCT, respectively. The mean thickness was 0.97+/-0.30 mm, 2.76+/-0.54 mm, and 0.81+/-0.24 mm, respectively. The mean liquefaction time was 174.8+/-108.2 seconds. The mean total number of pulses was 4799+/-3007.There was no significant difference between the density of each area of lens (anterior cortex, nucleus, posterior cortex, and total lens) and liquefaction time (p>0.05), and between the thickness of each area of lens and liquefaction time (p>0.05). There was no significant difference between the density of each area of lens and total number of pulses (p>0.05), and between the thickness of each area of lens and total number of pulses (p>0.05). CONCLUSIONS: When extraction of soft to moderate density cataract was performed with AquaLase(R), liquefaction time and total number of pulse did not correlate to the density and thickness of lens.
Adult ; Aged ; Cataract/*pathology ; Female ; Humans ; Lens, Crystalline/*pathology ; Male ; Middle Aged ; Phacoemulsification/instrumentation/*methods ; Photography ; Time Factors

This paper presents a medical image acquisition and analysis method-TRM (Topology Resolve-Map) Model-under natural light condition indoors. Firstly, in accordance to medical image color characteristics, a colorful and grayscale color control patch was made for use as supervised color. "Topology Resolve-Map-Restoration" was carried on in LAB color space of the one-dimensional L* space and the two-dimensional a* b* space. Then, L* value was regulated by subsection regulation and a* b* value was regulated by triangulation topological cutting--close in on center of gravity method. After correction of the 198 color blocks in 22 pictures, the results showed that, by comparison with the standard value, the deltaL*, deltaC* and deltaE decreased significantly (P < 0.01) after correction by TRM. After correction, the difference in image's color is reduced, the color saturation is improved and the value is closer to true value. TRM model can significantly reduce the color difference of the medical image under natural light condition; it has a good effect on color correction.
Artificial Intelligence ; Calibration ; Color ; standards ; Humans ; Image Processing, Computer-Assisted ; methods ; Pattern Recognition, Automated ; methods ; Photography ; instrumentation ; methods

PURPOSE: We evaluated various preoperative anterior segment parameters measured with a Pentacam rotating Scheimpflug camera and compared them with those of conventional methods. We also evaluated the effect of different parameters on corneal endothelial cells after cataract surgery. METHODS: Pentacam examination was performed in 88 eyes from 88 patients to evaluate central anterior chamber depth (ACD(pentacam)), nuclear density (Densitometry(pentacam)), anterior chamber volume (ACV), and lens thickness (LT(pentacam)). We compared values of ACD(pentacam) with those of ultrasound (ACD(sono)) and also compared Densitometry(pentacam) values with those of Lens Opacities Classification System (LOCS III) classification. We evaluated the effect of the following preoperative values measured with Pentacam on postoperative endothelial cell loss: pupil size measured both preoperatively and before capsulorrhexsis (Pupil(CCC)), amount of viscoelastics, and LT measured by ultrasound (LT(sono)). RESULTS: A significant concordance was found between the two grading methods of nuclear opacity: Densitometry(pentacam) and LOCS III classification (tau(b) = 0.414, p = 0.000). We also found a positive correlation between ACD(pentacam) and ACD(sono) (r = 0.823, p = 0.000) and between ACD(pentacam) and ACV (r = 0.650, p = 0.000). There were significant differences between the results of LT(pentacam) and LT(sono). The final regression model identified Densitometry(pentacam), viscoelastics and Pupil(CCC) as independent predictors of decreased postoperative corneal endothelial cell density (CD) at postoperative day 3, and Densitometry(pentacam), viscoelastics, and ACV as independent predictors of decreased CD two months postoperatively (p<0.05). CONCLUSIONS: Good agreement was found between all results obtained with the Pentacam and conventional methods except LT. Analyzing anterior chamber parameters preoperatively using Pentacam could be helpful to predict postoperative endothelial cell loss.
Adult ; Aged ; Aged, 80 and over ; Anterior Chamber/*pathology/ultrasonography ; Cataract/classification ; Cataract Extraction/*methods ; Corneal Endothelial Cell Loss/*diagnosis ; Female ; Humans ; Linear Models ; Male ; Middle Aged ; Photography/*instrumentation ; Predictive Value of Tests

PURPOSE: To evaluate retinal nerve fiber layer (RNFL) defect by a new scoring system for RNFL photography using the Heidelberg Retina Angiograph 1 (HRA1). METHODS: This retrospective study included 128 healthy eyes and 836 primary open-angle glaucoma eyes. The RNFL photography using HRA1 was interpreted using a new scoring system, and correlated with visual field indices of standard automated perimetry (SAP). Using the presence of RNFL defect, darkness, width, and location, we established the new scoring system of RNFL photos. RESULTS: The mean RNFL defect score I in the early, moderate, severe, and control groups were 7.3, 9.2, 10.4, and 3.6, respectively. The mean RNFL defect score II in the early, moderate, severe, and control groups were 14.5, 28.5, 43.4, and 3.4, respectively. Correlations between the RNFL defect score II and the mean deviation of SAP was the strongest of the various combinations (r=-0.675, P<.001). CONCLUSIONS: Using a new scoring system, we propose a method for semi-quantitative interpretation of RNFL photographs. This scoring system may be helpful to distinguish between normal and glaucomatous eyes, and the score is associated with the severity of visual field loss.
Equipment Design ; Female ; Fluorescein Angiography/*instrumentation ; Fundus Oculi ; Glaucoma, Open-Angle/*classification/pathology/physiopathology ; Humans ; Male ; Middle Aged ; Nerve Fibers/*pathology ; Perimetry ; Photography/*instrumentation ; Reproducibility of Results ; Research Design/*statistics & numerical data ; Retinal Ganglion Cells/*pathology ; Retrospective Studies ; Severity of Illness Index ; Visual Fields