Friday, February 24, 2006

Medical Lasers—Breaking New Ground

Lasers are indispensable for many medical applications today including aesthetic, dental, ophthalmic, and biotech. Technologies related to lasers continue to push the boundaries. One trend is the shift to fiber-based lasers away from optic resonators. These lasers use fiber optics to generate laser beams rather than the traditional optic resonator method which eliminates alignment, thermal, contamination, and other issues. Fiber lasers are much more efficient than conventional lasers. Other advantages include lower operating cost, no maintenance cost (no diodes or flashlamps to replace), smaller size, and smaller spot diameters. Optical fibers can be used to bring the laser to the target area which may be inside the human body. In this article, MIT Review describes how researchers used a semiconducting material within the fiber line to detect defects in the fiber casing and shut down the laser to prevent leakage.

Tunable lasers solve numerous applications including assessing airway passages in lungs without the need for reagents to measure exhalation particles. Ekips Technologies, in Oklahoma developed the Breathmeter which uses mid-infrared diode lasers to measure specific molecules using the technique called vibrational absorption spectroscopy. Tunable lasers and gold nanoparticles are being used to research heart treatments. The Imperial College of London announced that lasers can also be used instead of X-rays to measure bone density by measuring the amount of collagen. The technique goes beyond measuring the strength of the bone to predicting the bone’s risk of fracturing.

The Fraunhofer-Institut uses modified femtosecond lasers for nanomedicine in which small holes are drilled into cellular membranes to transfer genes.

Raman Spectroscopy lasers are used in glucose monitoring by measuring the change in the color of light as it passes through a blood vessel. LightTouch Medical is one company (of many) who use this technique.

In the area of aesthetic lasers, Reliant Technologies uses Fractional Photothermmolysis which produces microscopic heating on the skin with space in between each microscopic spot. This leaves much of the skin in tact and thus healing time is faster.

As for lasers in the dental area, there is more work to be done. Typically, dental lasers use erbium: yttrium-aluminum-garnet (Er:YAG) to remove layers of decayed tooth and prepare it for a filling. But as this article observes, it has many limitations and is not widely used today.

In the area of ophthalmic lasers, researchers combine excimer lasers with wavefront technology which measures the reflected light in the cornea and corrects for any aberrations. Today’s machines measure about 2000 datapoints in the light coming from the eye. The FDA has cleared the technology for commercialization. Additional information can be found in this article.

Some lasers for medical applications are moving from emerging technology status to commercialization. This press release, from Genetic Engineering News predicts exponential growth of tunable lasers from $5M to $2B in six years. Research and Markets offers a research report here.

Best regards,
Hall T.

Friday, February 17, 2006

Advanced Materials – Speeding the Luge in the Olympics

The Winter Olympic Games in Turin are now under way. It’s interesting to see emerging technologies at work in the winter sports. Austenitic steel is one example. Its high ductility and high tensile strength makes it an ideal element for the metal runners on the luge where riders reach 90 miles per hour and the timing of the race goes out to the thousandth of a second. Austenitic steel is used by the US luge team which contains precise levels of iron, manganese, chromium, and other metals. When the runners kit the ice, it changes into a form of Martensite. For some, Austenitic steel is not an emerging technology having been invented in 1882, but its application in the Olympics makes it interesting. Virtual Instrumentation brings measurement technology to steel production such as this example of corrosion testing.

Aside from the Olympics there are numerous advances in materials technology. The Airbus A380 pioneered the use of many new materials to support the large size of the plane. Advanced aluminum alloys and carbon fiber reinforced plastic materials were used in over 40% of the plane. GLAss fiber REinforced Aluminum GLARE weighs up to 30% less and allows for reorientation of the fibers in order to improve strength in a particular direction. This allowed the A380 engineers to “reorient” the material for various jobs on the airframe.

Advanced materials require new testing techniques which can be found in the area of non-destructive testing which has seen improved techniques. Non destructive testing falls into several categories including mechanical and optical, radiation penetration, electromagnetic and electronic, sonic and ultrasonic, thermal and infrared, and chemical and analytical. Virtual Instrumentation tests out various composite materials. Here’s an example from the University of Southampton comparing the strength of GLARE, Carbon-fiber reinforced plastic, and aluminum alloy.

Another emerging technology in advanced materials is metallic glass which provides improved mechanical properties such as high tensile strength and large elastic strains. Johns Hopkins researchers found that metallic glass which is formed by super cooling of liquid metal does not produce a completely random arrangement of molecules as previously thought, but rather an orderly arrangement of 7 or 15 atoms around a central atom, giving a non-conventional structure, but a structure nevertheless.

Best regards,
Hall T.

Friday, February 10, 2006

Wireless Mesh Networking -- Changing the Internet

Mesh networks could change the internet as we know it today. Sepp Hasselberger writes about this topic in his blog in which he makes several interesting points. Mesh networking enables municipal broadband which is in deployment in over 400 cities worldwide, and it’s expected to double this year. For those who are unfamiliar with mesh networking check out the definition in Wikipedia.

Mesh networking is considered a key technology for the developing world. In this downloadable book called “Wireless Networking in the Developing World” shows you how to build your own wireless mesh networking system using low-cost, commercially available equipment. The book starts with a primer on wireless technology including protocols with a focus primarily on WiFi. It then goes into various issues such as how to power a mesh network even when there’s no power grid available. (Hint: See last week’s post on this blog.) It provides practical advice for installing the nodes so they can survive harsh weather conditions. This is one of the more practical books I’ve seen on the topic of mesh networking and to top it off, it comes as a free download with a “Creative Commons” license.

Will Kelly writes a piece for Processor magazine on the benefits of mesh networking. I noticed a nice factoid at the bottom of the page from the CEO of Firetide another vendor of mesh networking equipment. Mesh networking can solve physical security issues by placing IP-based cameras around a facility and linking them through mesh networking technology. By removing the wiring burden and providing the ability to move the cameras around at will, a company can save a substantial amount of money in deploying camera security.

Companies offering wireless mesh networking systems are gaining recognition. Strix Systems, Locustworld, and Packethop Communications are some of the up and coming players in this area.

Microsoft is jumping on the bandwagon by offering a Mesh Networking Academic Resource Toolkit 2005 with a free download here. The driver software plugs into Microsoft Windows and provides a layer that makes the ad hoc network appear as a virtual network link.

A rich resource of information related to Wireless Mesh Networks is the Community Wireless, which is an umbrella organization for mesh networking. Another group offering a community-style access to WiFi is FON which has an impressive list of supporters from around the world.

Virtual instrumentation can make use of wireless mesh networking if no other reason than to eliminate the wiring cost typically associated with major applications. Wiring costs can run anywhere from $40/foot to $2000/foot. In addition one can add or remove nodes without impacting the system.

Best regards,
Hall T.

Friday, February 03, 2006

Alternative Energy – Using Water, Earth, Wind, and Fire

With the price of oil above $50 a barrel and everyone pronouncing the end of “cheap oil” there’s an expected interest in alternative energies such as solar, wind, and ocean power. Emerging technologies play a key role in making alternative energy viable.

For solar power, emerging technologies bring, Stirling engines fitted to a solar array panel farm. In this pilot plant for the state of California, 37-foot solar panels focus sunlight on a Stirling engine which is a highly efficient engine.

Stirling engines use a fixed amount of gas within an engine. Unlike an internal combustion engine which transfers gases in and out, the Stirling engine does not release any gases. By increasing the temperature and pressure in a cylinder, the Stirling engine generates movement of a piston and enough energy to reset the piston for the next cycle of operation.

Here’s an example in which virtual instrumentation controls the positioning of the solar array panels to generate optimum energy.

Wind power is the fastest growing alternative energy. The key to making wind power affordable is to make the turbine bigger so that it can generate more electricity with each rotation of the turbine blade. Virtual instrumentation plays a key part in this sector by monitoring the wind turbine for vibrations. Also, wind power generates swags and swells in the generated electricity due to fluctuations in the wind. Electrical power monitoring plays an important role in making wind turbines cost efficient. Here’s an example in which LabVIEW provides data acquisition and machine control.

Ocean power captures energy from the waves as they come ashore. Here’s one example of capturing energy from a wave of water by placing a chamber in a structure along the shore. As the water enters the chamber, it forces air through a compressor generating power.

Ethanol is processed corn which burns cleanly. In this article the authors created a model measuring net energy usage for ethanol and comparing it to fossil fuels. The article verifies the efficiency of ethanol over gasoline. An emerging technology, called cellulosic technology improves the process by using bacteria to convert the fiber content of plants (cellulose) into starches that can be fermented by other bacteria to produce ethanol. Virtual instrumentation brings advanced sensors and graphical software to the measurement of ethanol and control to the process of manufacturing it.

Biofuels use plants to create fuel. A variation of ethanol is biodiesel which uses plant matter, roots, stems, leaves and all as a biomass material. It is cheaper and easier to make than ethanol because it doesn’t require the process of distillation that ethanol requires. In this application a university team measured engine performance running biodiesel fuel by using virtual instrumentation.

Technology continues to improve the viability of alternative energies and virtual instrumentation supports these technologies.

Best regards,
Hall T.