Image coding by count sample, motivated by the mechanisms of light perception in the human visual system.

The paper presents the results of a study of input video data adequate formation/coding in modern imaging systems. Adequacy is understood here as the maximal correspondence between the ways of the radiation registration by material detectors and the ways of data coding in the retina of the human visual system. In this connection, the paper discusses general statistical issues of (photo) counts photoelectric detection and, on this basis, formalizes the concept of an ideal image formation by (ideal) visualization device. The problems arising in practice when working directly with ideal images are discussed and a method of their reduction to count sample of fixed (controllable) size, which, in fact, constitute the representation (coding) of registered data, is proposed. Results of illustrative computational experiments on count coding of the common digital images given by pixel data are presented. Examples of count samples of different sizes generated for the tested digital image are given. Based on the given results, the dependence of characteristics of sampling representations on the parameter of sample size is discussed.

Examination of the Dorsal Finger Vein Anatomy Using a Vein Visualization Device

Background: The vein anatomy of the dorsal finger is often difficult to identify suitable veins for anastomosis when treating digital amputations, but it has not been well studied to date. The aim of our study was to determine the vein anatomy of the dorsal finger using a vein visualization device. Methods: The study sample consisted of 20 volunteers (11 men and 9 women; 148 fingers and 37 thumbs). The number and location of veins, the distance from the finger midline to the most central vein, and the distance from the central vein to the adjacent vein were examined using a vein visualization device, Stat Vein®, at the eponychial level, distal interphalangeal (DIP) joints, and proximal interphalangeal joints. Results: In the finger, the distance from the nail lunula edge to the vein at the eponychial level was about 5 mm and that from the central vein to the adjacent vein at the DIP joints was about 8 mm. In the thumb, the distance from the nail lunula margin to the vein at the eponychial level was about 5 mm and that from the central vein to the adjacent vein at the interphalangeal joints was about 6 mm. Conclusions: Treatment of DIP joint-level finger amputation requires identification of the central vein at first and then the site about 8 mm away from the central vein. In the treatment of eponychial-level finger amputation, the vein is found about 5 mm away from the nail lunula edge.

A Sinter Visualization Device for Observing the Relationship Between Fillers and Porosity of Precursor-Derived Ceramic Coatings

Adding fillers to polysilazane (PSZ)-derived ceramic coating is one of the main methods used to reduce PSZ porosity. In this study, we designed a sinter visualization device for understanding the effect of fillers on coating porosity and observed pore evolution within the coating sintering process using different filler ratios. When there was no filler in the coating, gas evolution occurred at the initial sintering stage due to a PSZ pyrolysis reaction. In the final stage, numerous cracks appeared because of volume shrinkage. It was determined that such coatings cannot provide good protection. Although the cracks disappeared after adding glass powder, many bubbles appeared. After adding ZrO2, the bubbles in the coating significantly reduced. When the volume ratio of PSZ/glass powder/ZrO2 was 1:2:1, the coating porosity after sintering was the lowest. Based on our visualization experimental results, we concluded that the glass powder’s healing effect and the ZrO2 skeleton effect were the main reasons for the reduced coating porosity. In addition, the sinter visualization device can be used to observe the surface morphology of other similar coatings during the sintering processes.

Veins projection performance based on ultrasonic distance sensor in various surface objects

Intravenous therapy aims to inject fluids such as medicine or nutritions into the body via vein vessel. This procedure is needed in various cases whether in an ordinary or emergency. Every person has a different difficulty level thus a nurse usually encountered a problem when locating the position of vein vessel. A visualization device that able to work in realtime and have high mobility is really necessary for an emergency situation to speed up the intravenous access. In this study, a stand-alone veins visualization system was developed. The back-projection method that can adjust based on distance was used to speed up the visualization process. The distance between the device and the object is obtained by an ultrasonic distance sensor. The results of this projection method with a flat surface have maximum shift of 0.48 mm. While on various surfaces, projection shifts under 0.9 mm reach 89% from 140 measurement points. Projection shifts that reach more than 0.9 mm occurred due to the sensor readings are on steep curvature or large angles between segments and sensors.

3D Exoscope System in Neurosurgery—Comparison of a Standard Operating Microscope With a New 3D Exoscope in the Cadaver Lab

BACKGROUND For decades, the operating microscope has been the “gold standard” visualization device in neurosurgery. The development of endoscopy revolutionized different surgical disciplines, whereas in neurosurgery, the endoscope is commonly used as an additional device more than as single visualization tool. Invention of a 3D exoscope system opens new possibilities in visualization and ergonomics in neurosurgery. OBJECTIVE To assess the prototype of a 3D exoscope (3D exoscope, year of manufacture 2015, FA Aesculap, Tüttlingen, Germany) as neurosurgical visualization device in comparison to a standard operating microscope. METHODS A pterional approach was performed in 3 ETOH-fixed specimens (6 sides). A standard operating microscope was compared to a 3D exoscope prototype. Dimensions like visual field, magnification, illumination, ergonomics, depth effect, and 3D impression were compared. RESULTS In all approaches, the structures of interest could be clearly visualized with both devices. Magnification showed similar results. The exoscope had more magnification potential, whereas the visual quality got worse in higher magnification levels. The illumination showed better results in the microscope. Surgeons felt more comfortable with the 3D exoscope, concerning ergonomic considerations. Depth effect and 3D impression showed similar results. None of the surgeons felt uncomfortable using the exoscope. CONCLUSION The operating microscope is the gold standard visualization tool in neurosurgery because of its illumination, stereoscopy, and magnification. Nevertheless, it causes ergonomic problems. The prototype of a 3D exoscope showed comparable features in visual field, stereoscopic impression, and magnification, with a clear benefit concerning the ergonomic possibilities.