Technology Bulletin

Ground control on its way out

A report from Frost and Sullivan indicates that the world's commercial avionics market is switching from a system based on ground control crews to one that uses global positioning systems. "The industry is in a phase where we are moving away from the reliance on radio signals," says Michel Merluzeau, the industry analyst who wrote the report. "What this move means is that we'll have better coverage, especially in areas where radio signals haven't covered well in the past," he says. He also indicates that management of air traffic—positioning a plane for landing, for example—is more precise with a global positioning system. The implementation of communi- cation-navigation-surveillance (CNS) and air-traffic-management (ATM) equipment is driving a modernization of cockpits. Digitization of the avionics industry translates into greater air traffic efficiency, according to Merluzeau. Using auto dependent surveillance broadcast (ADSB), the cockpit crew in one airplane can relay information about its position to other airplanes in the area. "When planes relay positioning information to each other, we can safely reduce the spacing between airplanes during runway approaches at an airport. This allows a greater number of airplanes to land in the airport during a given period of time," he says. Contact Merluzeau at mmerluzeau@frost.com or call (650) 237-4951.

Contamination tests standardized

The multi-pass filter test uses particle counters to determine the efficiency of hydraulic filters. "In the past, we could not be certain that labs always counted and sized the test contaminant, dust particles, in the same way, due to shortcomings in the old particle counter calibration standard," says Barry Verdegan, the principal scientist at Nelson Industries. Verdegan chaired the National Fluid Power Association (NFPA) Contamination Technology Committee that helped produce a new standard, ISO 11171:1999, used to calibrate the particle counters that monitor contamination levels in oil and to determine filter efficiency. Advances in contamination control include the use of calibration reference material that is traceable to the U.S.'s National Institute of Standard's and Technology (NIST). A related standard (ISO 11943:1999) covers the calibration and validation of on-line particle counting systems used to test filters. Finally, ISO 16889:1999 is the revised multi-pass standard that measures filter performance using ISO Medium Test Dust (ISO 12103-1:1997). As a result of the three new ISO standards, the industry has, for the first time, NIST-traceable filter performance results. The new standards are available from NFPA, including ISO 4406:1999—a shorthand method of expressing contamination in hydraulic fluid, and others dealing with updating filter test procedures. For information, call Carrie Tatman Schwartz at the NFPA at (414) 778-3353, e-mail pubsales@nfpa.com ,  or fax the NFPA at (414) 778-3361.

3D imaging detects cancer

Three-dimensional Doppler ultrasound uses sound waves and color for revealing how quickly blood is moving in human blood vessels. Measuring the blood flow to problematic areas of the body helps doctors locate the growth of cancer cells and distinguish the malignant tissue from benign masses. The ultrasound technique also detects signals of increased blood vessel formation in a cancerous area before any other type of imaging method can, according to Paul Carson, a University of Michigan professor of radiology and bioengineering who leads the team developing the ultrasound technique. In a study of 38 women, 20 of whom had malignancies in their breasts confirmed by biopsy, ultrasonographers distinguished between cancerous tumors and benign masses 100% of the time by combining 3D color images with conventional black-and-white images of the same region. The first black-and-white image provides information about the breast tissue, which is full of ligaments, ducts, and other structures that vary from woman to woman. The second ultrasound image measures the Doppler shift of blood in the vessels. Carson and his colleagues developed an attachment for a conventional ultrasound wand that records its position into three dimensions as it moves across the breast. They also developed software that takes results from a series of side-to-side blood flow scans and combines them into 3D pictures that show blood flow. "Mammography only finds about 85% of all cancers, so we need an additional method of detection," says Carson's colleague Marylin Roubidoux. Carson adds that the 3D color Doppler should be used as an addition to, and not a substitute for, traditional cancer detection methods. "Our primary contribution is in the careful application of 3D, which led to better-than-usual trial results. An extended field of view, the ability to register the whole breast, and multiview imaging are examples of possible 3D improvements," says Carson. For information call (734) 764-2220.