Usability of prostaglandin monotherapy eye droppers

AIM: To determine the force needed to extract a drop from a range of current prostaglandin monotherapy eye droppers and how this related to the comfortable and maximum pressure subjects could exert. METHODS: The comfortable and maximum pressure subjects could apply to an eye dropper constructed around a set of cantilevered pressure sensors and mounted above their eye was assessed in 102 subjects (mean 51.2±18.7 years), repeated three times. A load cell amplifier, mounted on a stepper motor controlled linear slide, was constructed and calibrated to test the force required to extract the first three drops from 13 multidose or unidose latanoprost medication eye droppers. RESULTS: The pressure that could be exerted on a dropper comfortably (25.9±17.7 Newtons, range 1.2-87.4) could be exceeded with effort (to 64.8±27.1 Newtons, range 19.9-157.8; F=19.045, p<0.001), and did not differ between repeats (F=0.609, p=0.545). Comfortable and maximum pressures exerted were correlated (r=0.618, p<0.001), neither were influenced strongly by age (r=0.138, p=0.168; r=-0.118, p=0237, respectively), but were lower in women than in men (F=12.757, p=0.001). The force required to expel a drop differed between dropper designs (F=22.528, p<0.001), ranging from 6.4 Newtons to 23.4 Newtons. The force needed to exert successive drops increased (F=36.373, p<0.001) and storing droppers in the fridge further increased the force required (F=7.987, p=0.009). CONCLUSIONS: Prostaglandin monotherapy droppers for glaucoma treatment vary in their resistance to extract a drop and with some a drop could not be comfortably achieved by half the population, which may affect compliance and efficacy

Smartphone-Based pH Sensor for Home Monitoring of Pulmonary Exacerbations in Cystic Fibrosis.

Currently, Cystic Fibrosis (CF) patients lack the ability to track their lung health at home, relying instead on doctor checkups leading to delayed treatment and lung damage. By leveraging the ubiquity of the smartphone to lower costs and increase portability, a smartphone-based peripheral pH measurement device was designed to attach directly to the headphone port to harvest power and communicate with a smartphone application. This platform was tested using prepared pH buffers and sputum samples from CF patients. The system matches within ~0.03 pH of a benchtop pH meter while fully powering itself and communicating with a Samsung Galaxy S3 smartphone paired with either a glass or Iridium Oxide (IrOx) electrode. The IrOx electrodes were found to have 25% higher sensitivity than the glass probes at the expense of larger drift and matrix sensitivity that can be addressed with proper calibration. The smartphone-based platform has been demonstrated as a portable replacement for laboratory pH meters, and supports both highly robust glass probes and the sensitive and miniature IrOx electrodes with calibration. This tool can enable more frequent pH sputum tracking for CF patients to help detect the onset of pulmonary exacerbation to provide timely and appropriate treatment before serious damage occurs

Mobile app Aston contrast sensitivity test

BACKGROUND: Contrast detection is an important aspect of the assessment of visual function; however, clinical tests evaluate limited spatial frequencies and contrasts. This study validates the accuracy and inter-test repeatability of a swept-frequency near and distance mobile app Aston contrast sensitivity test, which overcomes this limitation compared to traditional charts. METHOD: Twenty subjects wearing their full refractive correction underwent contrast sensitivity testing on the new near application (near app), distance app, CSV-1000 and Pelli-Robson charts with full correction and with vision degraded by 0.8 and 0.2 Bangerter degradation foils. In addition repeated measures using the 0.8 occluding foil were taken. RESULTS: The mobile apps (near more than distance, p = 0.005) recorded a higher contrast sensitivity than printed tests (p  0.05). Although the coefficient of repeatability was lowest for the Pelli-Robson charts (0.14 log units), the mobile app charts measured more spatial frequencies, took less time and were more repeatable (near: 0.26 to 0.37 log units; distance: 0.34 to 0.39 log units) than the CSV-1000 (0.30 to 0.93 log units). The duration to complete the CSV-1000 was 124 ± 37 seconds, Pelli-Robson 78 ± 27 seconds, near app 53 ± 15 seconds and distance app 107 ± 36 seconds. CONCLUSIONS: While there were differences between charts in contrast levels measured, the new Aston near and distance apps are valid, repeatable and time-efficient method of assessing contrast sensitivity at multiple spatial frequencies

Industry-wide response to terror: a political economy analysis of the owner/operator sector of the U.S. motorcoach industry post 9-11

The authors develop a political economy framework to study the post- September 11th environmental changes and firm responses in the owner/operator sector of the U.S. motorcoach industry. Based on a comprehensive analysis of both evolutionary and revolutionary changes in the competitive and regulatory environments faced by the firms in this industry, their policy and strategic responses to the terrorist acts of September 11, 2001, on U.S. soil are examined. The industry’s response is captured (i.e., collective action response) by surveying 163 firms operating and competing in the owner/operator sector of the U.S. motorcoach industry. Several descriptive statistics are synthesized and analyzed for a structured presentation of the survey findings. In conclusion, contributions and limitations of this study, as well as directions for future research, are outlined

The importance of forecasting regional wind power ramping: a case study for the UK

In recent years there has been a significant change in the distribution of wind farms in Great Britain, with a trend towards very large offshore farms clustered together in zones. However, there are concerns these clusters could produce large ramping events on time scales of less than 6 hours as local meteorological phenomena simultaneously impact the production of several farms. This paper presents generation data from the wind farms in the Thames Estuary (the largest cluster in the world) for 2014 and quantifies the high frequency power ramps. Based on a case study of a ramping event which occurred on 3rd November 2014, we show that due to the large capacity of the cluster, a localised ramp can have a significant impact on the cost of balancing the power system on a national level if it is not captured by the forecast of the system operator. The planned construction of larger offshore wind zones will exacerbate this problem. Consequently, there is a need for accurate regional wind power forecasts to minimise the costs of managing the system. This study shows that state-of-the-art high resolution forecast models have capacity to provide valuable information to mitigate this impact

The influence of end of day silicone hydrogel daily disposable contact lens fit on ocular comfort, physiology and lens wettability

Purpose: To quantify the end-of-day silicone-hydrogel daily disposable contact lens fit and its influence of on ocular comfort, physiology and lens wettability. Methods: Thirty-nine subjects (22.1. ±. 3.5 years) were randomised to wear each of 3 silicone-hydrogel daily-disposable contact lenses (narafilcon A, delefilcon A and filcon II 3), bilaterally, for one week. Lens fit was assessed objectively using a digital video slit-lamp at 8, 12 and 16. h after lens insertion. Hyperaemia, non-invasive tear break-up time, tear meniscus height and comfort were also evaluated at these timepoints, while corneal and conjunctival staining were assessed on lens removal. Results: Lens fit assessments were not different between brands (P > 0.05), with the exception of the movement at blink where narafilcon A was more mobile. Overall, lag reduced but push-up speed increased from 8 to 12. h (P 0.05). Movement-on-blink was unaffected by wear-time (F = 0.403, P = 0.670). A more mobile lens fit with one brand did not indicate that person would have a more mobile fit with another brand (r = -0.06 to 0.63). Lens fit was not correlated with comfort, ocular physiology or lens wettability (P > 0.01). Conclusions: Among the lenses tested, objective lens fit changed between 8. h and 12. h of lens wear. The weak correlation in individual lens fit between brands indicates that fit is dependent on more than ocular shape. Consequently, substitution of a different lens brand with similar parameters will not necessarily provide comparable lens fit

Assessment of dysphotopsia in pseudophakic subjects with multifocal intraocular lenses

Aim: To better understand the phenomenon of dysphotopsia in patients implanted with multifocal intraocular lenses (IOLs). Methods: Forty-five patients (aged 61.8±8.9 years) implanted bilaterally with Tecnis ZM900 (diffractive multifocal), Lentis Mplus MF30 (segmented refractive multifocal) or Softec-1 (monofocal) IOLs (each n=15) 4–6 months previously and who had achieved a good surgical outcome were examined. Each reported their dysphotopsia symptoms subjectively, identified its form (EyeVisPod illustrations), quantified retinal straylight (C-Quant) and halo perception (Aston halometer). Retinal straylight and halometry was repeated by a second masked clinician to determine interobserver repeatability. Results: Subjective dysphotopsia ratings were able to differentiate Tecnis ZM900 from Lentis Mplus MF30 (p0.10) quantification or between straylight and the halo area (p>0.30). Conclusions: Multifocal IOLs induce symptoms of dysphotopsia. Straylight did not differentiate between IOL designs, however halometry identified clear differences in light scatter due to the IOL optics. Whereas, subjective rating of overall dysphotopsia are not strongly associated with straylight or halo perception, the halometry polar diagram reflected the subjective descriptions of dysphotopsia

Two-Photon Lif On The Hit-Si3 Experiment: Absolute Density And Temperature Measurements Of Deuterium Neutrals

Presented XXXXX; received XXXXX; accepted XXXXX; published online XXXXX) (Dates appearing here are provided by the Editorial Office) Two-photon laser-induced fluorescence (TALIF) measurements were performed on the helicity injected torus (HIT-SI3) device to determine the density and temperature of the background neutral deuterium population, and to demonstrate the diagnostic\u27s feasibility for use on short pulse fusion experiments. Measurements were taken in 2 ms long pulsed plasmas after the inductive helicity injectors were turned off. Attempts to measure neutrals during the main phase of the plasma were unsuccessful, likely due to the density of neutrals being below the detection threshold of the TALIF diagnostic. An unexpectedly low density of atomic deuterium was measured in the afterglow; roughly 100 times lower than the theoretical prediction of 1017 m-3. The neutral temperatures measured were on the order of 1 eV, much lower than the electron temperature (5-20 eV), which is consistent with predictions. Temporally and spatially resolved neutral density and temperature data are presented