Autofluorescence has great advantage on detecting premalignant lesions and early cancers which are not detectable by conventional white light endoscopy (WLE). In this review, the recent advances in autofluorescence for diagnosis of precancerous lesions and early cancers are presented. Varieties of endogenous fluorophores in biological tissues, the potential mechanisms of the autofluorescence differences between normal and abnormal tissues, the selection of light source and optimal excitation wavelengths, and effective algorithms for processing autofluorescence data are highlighted. Finally, the shortages and improvement directions of autofluorescence technique for the diagnosis of precancerous lesions and early cancers are briefly discussed.
Early Detection of Cancer ; methods ; Esophageal Neoplasms ; diagnosis ; Fluorescence ; Humans

With the development of capsule endoscopy, developing active capsule endoscopy robot becomes a growing trend. Although stomach diagnosis with robot has been put into clinical test, the realization of the complete intestinal capsule endoscopy is still a difficulty. This paper reports the status quo of the research process for intestinal capsule endoscopy robot, and analyzes their advantages, defects and prospects for development, which provides reference for the research of intestinal capsule endoscopy robot.
Capsule Endoscopy ; instrumentation ; Humans ; Intestines ; Robotics ; trends

OBJECTIVE: To study the effect of samples having different pH values in the bacterial endotoxins test (BET). METHODS: The BET was conducted as an assay of the concentration of endotoxins by using kinetic-turbidimetric technique. Samples having different pH values but containing same concentration reference standard endotoxin (RSE) were tested by TAL/LAL reagents. The average result on the standard curve was calculated and the mean recovery observed. RESULTS: The reagents had three highly sensitivities in pH 5.20, pH 7.83/pH 6.23 and pH 10.55. After adjustment to pH 6 to 8, the mean recovery was 76.5%～115.9% or 85.8%～99.8%. When the sample pH value was less than 3 or more than 12, the test was unsuitable for the inhibition test, and the mean recovery was less than 56.8%. CONCLUSION: It is necessary to adjust the pH of the solution to be tested in the BET, adjust the sample to pH (6.5～7.5) when using TAL reagents, and adjust to pH (6.2±0.1) or pH(6.7～7.8) when using LAL reagents.

Objective To develop a method for localizing a detecting capsule in the gastrointestinal tract.Methods A three-axis magnetic sensor was sealed in the detecting capsule.Three flat coils were fixed on patients' back.The coils were excited one by one to generate electromagnetic fields.The position and the orientation of the capsule could be determined by telemetering the signals from the magnetic sensor incorporated in the capsule.Results The telemetric localization system worked successfully.A localization model describing the relationship between the magnetic field strength and the position and orientation of the capsule,was correctly established basing on the principle of magnetic dipoles,and neural network algorithm was employed to solve a non-linear equation set.Conclusion The results showed that the localization method is feasible and the precision is higher than existing methods.The localization device can perform consecutive tracking and can be made into a portable type.After putting into practice,the device can also be used in food selection for astronauts by monitoring their gastrointestinal parameters in space.

Traditional capsule image collects and transmits analog image, with weak anti-interference ability, low frame rate, low resolution. This paper presents a new digital image capsule, which collects and transmits digital image, with frame rate up to 30 frames/sec and pixels resolution of 400 x 400. The image is compressed in the capsule, and is transmitted to the outside of the capsule for decompression and interpolation. A new type of interpolation algorithm is proposed, which is based on the relationship between the image planes, to obtain higher quality colour images. capsule endoscopy, digital image, SCCB protocol, image interpolation
Algorithms ; Capsule Endoscopy ; instrumentation ; Equipment Design ; Image Processing, Computer-Assisted

Because the huge number of images of the digestive tract by Wireless Capsule Endoscopy (WCE) are left to the medical personnels detected by their eyes, huge burden leaves to doctors. This article provides a classification of method based on SVM (Support Vector Machine) for the capsule endoscopy bleeding intelligent recognition. We created a new kind of feature parameter, and the experiment result can reach 83% specificity and 94% sensitivity.
Capsule Endoscopy ; Gastrointestinal Tract ; pathology ; Hemorrhage ; diagnosis ; Humans ; Sensitivity and Specificity ; Support Vector Machine

The work of research and development of noninvasive monitoring system for human GI (gastrointestinal tract) has been very successful all over the world, and without questions, the system as such will extensively be applied in the future. However, the method for localization of the monitoring capsule in the system is not perfect. This paper reports the status quo of the research process for the capsule localization system, and analyzes their advantages and defects.
Biosensing Techniques ; Capsule Endoscopes ; Capsule Endoscopy ; methods ; trends ; Equipment Design ; Gastrointestinal Tract ; Humans

Using the method of detrended fluctuation analysis (DFA) and power spectral analysis (PSA), the paper deals with the characteristics of long-range correlations of colonic pressure activities and their surrogate data of healthy subjects. The DFA is a period representation of such correlations, whereas the PSA is a frequency representation. The analysis of the two methods consistently shows that there are long memories in colonic pressure activities and there exist long-range correlations, whereas there are no such long memories and long-range correlations in the surrogate data, whose sequential orders are randomly shuffled. The results to some extent indicate that human colonic pressure activities with normal motilities do have long memories, but these memories may be weaker or may even be destroyed with dysmotilities.
Adult ; Colon ; physiology ; Data Interpretation, Statistical ; Female ; Humans ; Male ; Middle Aged ; Pressure ; Signal Processing, Computer-Assisted

To probe further into the viscosity of gastrointestinal mucus, the samples of gastrointestinal mucus were taken from fifty normal people and were tested with Low-Shear 30 viscometer, and then the viscosity model was obtained. The results indicated that the apparent viscosity of large intestine mucus is greater than that of small intestine and stomach. The gastrointestinal mucus is a kind of non-Newtonian fluid when its apparent viscosity rapidly decreases with the increase of shear rate. When the shear rate increase well enough, the apparent viscosity of gastrointestinal mucus becomes a constant, and the gastrointestinal mucus appears to be a Newtonian fluid.
Adolescent ; Adult ; Aged ; Female ; Gastrointestinal Tract ; chemistry ; Humans ; Male ; Middle Aged ; Mucus ; chemistry ; Rheology ; Viscosity ; Young Adult

In order to deliver power to the capsule endoscope, whose position and orientation are always changing when traveling along the alimentary tract, a wireless power transmission system based on electromagnetic coupling was proposed. The system is composed of Helmholtz transmitting coil and three-dimensional receiving coil. Helmholtz coil outside the body generates a uniform magnetic field covering the whole alimentary tract; three-dimensional coil inside retrieves stable power regardless of its position and orientation. The transmitter and receiver were designed and implemented, and the experiments validated the feasibility of the system. The results show that at least 320 mW of usable power can be transmitted to capsule endoscope when its position and orientation are changing at random and the transmitting power is 25W.
Capsule Endoscopes ; Capsule Endoscopy ; instrumentation ; Electric Conductivity ; Electric Power Supplies ; Electromagnetic Fields ; Equipment Design ; Gastrointestinal Diseases ; diagnosis ; Humans