Narrow Results

An unusual problem occurred during the endoscopic carpal tunnel release procedure of a patient with carpal tunnel syndrome. The endoscope was damaged because of inadequate knowledge in handling the instruments. The procedure was completed smoothly with a knee arthroscope.

Research to Test GM Mouse Herpes Virus.

National Bio-Chip Research Center To be Constructed in Shanghai.

Meditation and Vegetarian Diet Can Combat Parkinson’s.

Fujitsu Develops Contact-Free ID System.

Korea Develops World’s Smallest Endoscope.

Red Color in Leaves Has Health Benefits.

Olympus's Latest High-Resolution Endoscope.

The present studies deal with the peristaltic motion of an incompressible Williamson fluid model in an endoscope. The governing equations of Williamson fluid model are first simplify using the assumptions of long wavelength and low Reynolds number. The four types of solutions have been presented for velocity profile named (i) exact solution, (ii) perturbation solution, (iii) HAM solution, and (iv) numerical solutions. The comparisons of four solutions have been found a very good agreement between all the solutions. In addition, the expressions for pressure rise and velocity against various physical parameters are discussed through graphs.

In this article, we considered the peristaltic flow of Newtonian incompressible fluid of chyme in small intestine. The analysis has been performed using an endoscope. The peristaltic flow of chyme is modeled by assuming that the peristaltic wave is formed in non-periodic mode comprising two sinusoidal waves of different wave lengths propagating with same speed along the outer wall of the tube. Heat transfer mechanisms have been taken into account, such that the constant temperature and are assigned to inner and outer tubes, respectively. A complex system of equations has been simplified using long wavelength and low Reynolds number approximation because such assumptions exist in small intestine. Exact solutions have been carried out for velocity temperature and pressure gradient. Graphical results have been discussed for pressure rise, frictional forces, temperature, and velocity profile. Comparison of present results with the results of the existing literature have been presented through figures. Trapping phenomena have been presented at the conclusion of the article.

In the present paper, we have studied the effects of endoscope and heat transfer on the peristaltic flow of second grade fluid through an inclined tube. The endoscope is a solid circular cylinder which is inserted in a peristaltic tube, and the flow takes place through the gap between endoscope and the peristaltic tube. The endoscope is maintained at a temperature $T_1$, while the outer tube has a sinusoidal wave traveling down its wall and is exposed to temperature $T_0$. The flow is investigated in a wave frame of reference moving with the velocity of the wave. The equations governing the flow of second grade fluid are modeled in cylindrical coordinates. Using perturbation method, the solutions are obtained for the stream function, pressure gradient and temperature fields. The pressure difference and frictional force at both the walls are calculated using numerical integration. The graphical results are presented to interpret the effect of various physical parameters of interest. It is found that, velocity increases with an increase in inclination angle and the best pumping rate appear in the vertical tube as compared to the horizontal tube. It is also found that, the heat generation parameter has an increasing effect on the velocity of the fluid.

This paper describes a new model for obtaining analytical solutions of peristaltic flow through eccentric annuli. A mathematical model of peristaltic pumping of a fluid mixture (as blood model) in a circular eccentric cylinders is presented and it is motivated due to the fact that thread injection is a promising method for placing medical implants within the human body with minimum surgical trauma. For the eccentric annuli, the inner cylinder is rigid and moving with a constant velocity V, and the outer one is hollow flexible cylinder that has a sinusoidal wave traveling down its wall. The coupled differential equations for both the fluid and the particle phases have been solved by using two methods and the expressions for the velocity distribution of fluid and particle phase, flow rate, pressure drop, friction forces at the inner and outer cylinders have been derived. The results obtained are discussed in brief. The significance of the particle concentration and the eccentricity parameter as well as the nature of the basic flow has been well explained.

Brillouin imaging (BI) for micromechanical characterization of tissues and biomaterials is a fast-developing field of research with a strong potential for medical diagnosis of disease-modified tissues and cells. Although the principles of BI imply its compatibility with in vivo and in situ measurements, the integration of BI with a flexible catheter, capable of reaching the region of interest within the body, is yet to be reported. Here, for the first time, we experimentally investigate integration of the Brillouin spectroscope with standard optical fiber components to achieve a Brillouin endoscope. The performance of single-fiber and dual-fiber endoscopes are demonstrated and analyzed. We show that a major challenge in construction of Brillouin endoscopes is the strong backward Brillouin scattering in the optical fiber and we present a dual-fiber geometry as a possible solution. Measurements of Brillouin spectra in test liquids (water, ethanol and glycerol) are demonstrated using the dual-fiber endoscope and its performance is analyzed numerically with the help of a beam propagation model.

We present a robust and fiducial-marker-free algorithm that can identify and correct stick-slip distortion caused by nonuniform rotation (or beam scanning) in distally scanned catheters for endoscopic optical coherence tomography (OCT) images. This algorithm employs spatial frequency analysis to select and remove distortions. We demonstrate the feasibility of this algorithm on images acquired from ex vivo rat colon with a distally scanned DC motor-based endoscope. The proposed algorithm can be applied to general endoscopic OCT images for correcting nonuniform rotation distortion.

A major challenge of minimally invasive surgery (MIS), particularly in laparoendoscopic single site (LESS) surgery, is trocar crowding. Trocar crowding causes instruments fencing, limited instrument access and limited endoscope views. It also increases the workload of surgeons. One strategy to alleviate the problem is to use magnetic anchored and guided system (MAGS). Existing MAGS endoscopes are assembled by multiple miniature components and actuated by onboard motors. This makes them complex, difficult to manufacture as well as requires additional power consumption. In this work, we present a novel soft-bodied magnetic anchored and guided endoscope, which comprises of a silicon structure, the magnets and a wireless camera module. The developed endoscope incorporates benefits of both MAGS (e.g. wireless steering and translation) and soft-bodied devices (e.g. compactness, lightweight, safety and simple fabrication). We model the moment loads experienced by the silicon structure to optimize the design of the endoscope. Performance and feasibility of the endoscope are validated using both benchtop setting and animal cadaver.

In this work, a prototype polyvinylidene fluoride (PVDF) tactile sensor for endoscopic application was developed. The aim of the sensor is to measure hardness, which is one piece of information determined from tactile perceptions. This sensor is composed of two PVDF films, a silicone cylindrical column, and an aluminum cylinder. The classification of hardness is concerned with the ratio between the outputs of these PVDF sensors. In this study, two sensors were fabricated using two silicone cylindrical columns with different Young's moduli. The performance evaluation of each sensor was conducted using six silicone rubbers as measuring objects. The experimental results corresponded with the simplified theoretical analysis and the proposed sensor can distinguish differences in elastic property.

A planar pneumatic endoscopic manipulator powered by compressed air is presented. The tip joint is manipulated by the operator through a Bowden cable and all other joints are driven and controlled by mechanically implemented feedback control law that produces propulsion like a snake. Unlike conventional active endoscopes, the proposed mechanism produces propulsion at every part of the body and thus can reach deeper part of a complicated cavity.