Development of a clockwork light source to enable cervical inspection by village health workers

BACKGROUND: Cervical cancer can often be prevented by screening and may be curable if identified and treated in its early stages. However, 80% of new cases occur in less-developed countries where cervical cancer screening programmes are small-scale or non-existent. This is a human tragedy of great proportion, with many of those affected being young mothers. There is some evidence that cancerous or precancerous lesions may be detected by visual inspection with acetic acid (VIA) and field studies indicate that this technique is effective, safe and acceptable to women. However, the provision of a light source for inspection of the cervix presents a major problem in less-developed countries, where candles and torches often provide the only means of illumination. Our objective was to develop a light source based on clockwork technology, that required no batteries or external power source. METHODS: We adapted the design of a commercially available clockwork torch to provide a light source for cervical inspection. The light source was then tested under laboratory conditions in a comparison with other illumination methods typically used in this application. RESULTS: The light source gave illuminance levels greater than those produced by any other method tested, and also had considerable advantages in terms of ease of use and safety. CONCLUSION: This design is small, compact, effective and safe to use and promises a better and more affordable means of visualising the cervix. Further field trials of VIA are now required which incorporate this light source

Thin Film Strain Gauge Sensors for ion Thrust Measurement

In order to measure the thrust produced by a Stationary Plasma Thruster, a measurement system has been developed using a thrust balance with thin film strain gauge sensors. For this purpose, strain gauges were designed and deposited on the columns of the thrust balance fabricated and necessary signal conditioning circuit has been used. Performance of the system developed was studied, in a vacuum chamber under space simulated conditions, by activating the thruster. In-situ calibration was done using Lami's principle. For discharge powers varying from 210-275 Watts, the measured values of thrust were found to be in the range of 11-16 mN with an accuracy of $\pm\hspace{5mm}1mN$ and resolution of 0.12 mN. Specific impulse and efficiency were also estimated

Strain gauge based thrust measurement system for a stationary plasma thruster

A thrust measurement system has been developed for the purpose of measuring the thrust produced by a stationary plasma thruster. The measurement system designed and fabricated mainly consists of a thrust balance assembly with strain gauge sensors and associated signal conditioning circuitry. Performance of the system developed was studied, in a vacuum chamber under space simulated conditions, by activating the thruster using xenon as the propellant. Details of the in situ calibration procedure followed are given. The thrust output for discharge powers ranging from 170 to 260 watts was measured and found to be in the range of 4–14 millinewtons. The measurement accuracy and resolution were found to be ±1 mN and 0.3 mN respectively. Specific impulse and thrust efficiency were also estimated

Thin-Film Strain Gauge Sensors for Ion Thrust Measurement

In order to measure the thrust produced by a stationary plasma thruster, a measurement system has been developed using a thrust balance with thin-film strain gauge sensors. For this purpose, strain gauges were designed and deposited on the columns of the thrust balance fabricated and necessary signal conditioning circuits have been used. The performance of the system developed was studied, in a vacuum chamber under space simulated conditions, by activating the thruster. In situ calibration was done using Lami's principle. For discharge powers varying from 210-275 W, the measured values of thrust were found to be in the range of 11-16 mN with an accuracy of \pm 1 mN and resolution of 0.12 mN. Specific impulse and efficiency were also estimated

Current research trends in external energy assisted machining

External energy assisted machining involves the use of a heating, cooling, and mechanical vibration source to facilitate the material removal process. A drastic attention on the external energy assistance is resulted from the requirements for newly developed hard and brittle materials machining and many activities to understand the mechanisms, processes, and the systems have been performed on both micro and macro scale in recent years. This paper attempts to provide an overview in the general idea of these areas with laser and plasma, cryogenic, and vibration assistances. The progresses made up to date will be explained in detail and finally, the future research directions in this area will be discussed.close1