National Trend of Uroflowmetry, Urodynamic Study and Cystoscopy Considering the Change in the Population Structure in Korea from 2010 to 2015.

BACKGROUND: Although lower urinary tract symptoms (LUTS) show a higher prevalence with age, few studies have reported the trend of these examination tools including uroflowmetry, urodynamic study and cystoscopy. METHODS: We evaluated the trend of performance of uroflowmetry, urodynamic study and cystoscopy by using National Health Insurance Data from 2010 to 2015. Primary outcome findings included cumulative number of patients per year, cumulative age-standardized patient rate per year and per age group, and correlation between the number of patients per year and the percentage of population per year in each age group. RESULTS: The overall trend for frequency of uroflowmetry and cystoscopy showed an increasing pattern (P < 0.001, respectively) while the trend for frequency of urodynamic study showed a decreasing pattern (P < 0.001). After age standardization, the overall trend showed similar results. Correlation between the number of patients per year and the percentage of population per year showed a positive correlation in the 50s age group and the above 70s age group (P = 0.003 and < 0.01, respectively) on uroflowmetry and in the above 70s age group (P < 0.01) on cystoscopy. Urodynamic study showed negative correlations in the 50s age group and the above 60s age group (P = 0.001 and 0.01, respectively). CONCLUSION: National trend for frequency of uroflowmetry, urodynamic study and cystoscopy showed a different trend. The increasing trend of uroflowmetry and cystoscopy was related with growth of the aged population. However, urodynamic study showed a decreasing trend regardless of the age group.

Optical delay interferometer based on phase shifted fiber Bragg grating with optically controllable phase shifter.

We propose a novel optical delay interferometer (ODI) with an optically controllable phase shifter. The proposed interferometer is implemented by using a phase shifted fiber Bragg grating and an Yb(3+)/Al(3+) co-doped optical fiber. The phase of the delayed optical signal is linearly controlled by adjusting the induced pumping power of a laser diode at 976 nm. Polarization dependent loss, polarization dependent center wavelength shift and temperature induced center wavelength shift of the ODI are 0.044 dB, 6 pm, and 9.8 pm/ degrees C, respectively.

All-optical 2 x 2 switching with two independent Yb3+ -doped nonlinear optical fibers with a long-period fiber grating pair.

We have demonstrated a new type of all-optical 2 x 2 switch by using two independent Yb3+ -doped nonlinear optical fibers with a long-period fiber grating pair and a 3-dB fiber coupler. A 400-Hz square-wave pulse train at approximately 1549.4 nm was fully switched between the two output ports up to 200 Hz by modulated pump signals at 976 nm with a maximum pump power of approximately 35 mW, where the extinction ratio at approximately 1549.4 nm between the on and the off states was approximately 17.5 dB.

Absorption and emission properties of Tm2+ ions in germanosilicate glass fibers.

Absorption and emission properties between 350nm and 1600nm of the Tm2+ ions in optical fibers were investigated using the Tm2+-Tm3+ co-doped germanosilicate glass fibers and its fiber preform. Strong broad absorption band due to Tm2+ ions was found to appear from 350nm to ~900nm together with the absorption bands due to Tm3+ ions. Broad emission from ~600nm to ~1050nm and the other emission from ~1050nm to ~1300nm, which were not shown in the Tm3+ ions, were found upon the Ar ion laser pumping at 515nm. Both absorption and emission results confirm that the Tm2+ ions in the germanosilicate glass have the 4f-5d energy band from 350nm to ~900nm and the 4f-4f energy level at ~1115nm.

Measurement method for profiling the residual stress and the strain-optic coefficient of an optical fiber.

A method, believed novel, is demonstrated for determining the strain-optic coefficient profile as well as the residual-stress profile of an optical fiber by use of a modified polariscope combined with a fiber-elongation apparatus. Measurement results of the residual-stress and the strain-optic coefficient profiles for Ge-doped and Er-Ge-Al-doped optical fibers are demonstrated with this method.