R&DDecember 1, 2006 By: Stephanie vL Henkel, Sensors Sensors
University of Missouri-Columbia researchers have found a way to detect the spread of melanoma, a particularly aggressive form of skin cancer, by listening to the sound melanin makes in the blood cells. With as few as 10 cells/sample, oncologists could spot early signs of metastasis before the disease settles in other organs.
This method, photoacoustic detection, combines laser optics and ultrasound by first separating the red blood cells from the plasma, vibrating the blood cells with a laser, and picking up the characteristic signal response of melanoma. The sample is placed in saline solution and exposed to brief bursts of intense blue-laser light. The presence of melanin makes melanoma the only type of of cancer whose cells strongly absorb all wavelengths of light. The abrupt expansion and shrinking of the melanin granules characteristic of melanoma emit cracking sounds that propagate in the saline. The diagnostic procedure could take only 30 min. to determine whether the cancer has begun to travel through the bloodstream, and early discovery could greatly increase the patient's chances for a successful outcome. (www.senorsmag.com/1206/RDCells)
Establishing Burn Depths
Determining the extent of a burn injury is difficult from visual inspection. At stake is a surgical procedure should the underlying blood vessels not be receiving the amount of oxygen needed for the surrounding tissue to regenerate. The National Research Council Canada has filed for a patent (www.sensorsmag.com/1206/RDPatent) for a noninvasive probe that would shine an intense beam of white light at the burn and pick up the reflected signal with four IR detectors. The detector nearest the skin would detect the reflection from a shallow depth; the other three would capture light scattered wider by deeper layers of flesh. A rosy color detected by the receptors would indicate the presence of oxygenated hemoglobin. Less light would indicate poor blood supply and less oxygen. (www.sensorsmag.com/1206/RDBurn)
A Touch of Genius
FingerTPS, a line of capacitive tactile pressure sensors mounted on stretchable fabric designed to be worn on a person's fingertips and palm, can measure the pressures exerted while the person uses a tool or performs some other action. The technology could also quantify pain by objectively determining the sensitivity of injured tissues to touch. Other applications include product design and CPR training for use on infants. (www.sensorsmag.com/1206/RDFinger)
Is That Meat Okay to Eat?
There's yet another food spoilage detector that can detect high levels of bacterial activity in poultry and other meats destined for the table. SensorfreshQ sniffs out biogenic amines that can be picked up by a handheld device that passes an air sample over the item of interest. The amines generate an electrical current that produces a color readout of green, yellow, or red (don't eat it). The ultimate plan is to include a version of the sensor in the product packaging. (www.sensorsmag.com/1206/RDMeat)
And Check the Silverware Too
At Cornell University, researchers are working on a new table napkin made of nanofibers that can advise of the presence of microorganisms you don't want to ingest. Coated with antibodies, proteins, and dyes, these wipes have successfully identified E. coli by assuming a yellow hue. Adrian Monk will doubtless be first in line to buy them. (www.sensorsmag.com/1206/RDNapkin)
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