This month we have monitoring bacteria in wastewater, fiber-optic sensors for electrical utilities, and a transmitter that may help to regenerate cartilage in knees.
Watching Wastewater
Did you know that bacteria are necessary for wastewater treatment? It's true. And, thanks to Purdue University researchers Eric McLamore, Marshall Porterfield, and M. Katherine Banks, it's now possible to monitor the health of these organisms in situ and get an early warning if things are amiss. In its normal, happy state, Nitrosomonas europaea converts ammonia (prevalent in human waste and agricultural runoff) into nitrites, which are then broken down into nitrogen by other bacteria. When it is stressed, however, it starts to release potassium, calcium, and other ions, so by monitoring the ion flux of the biofilms the researchers could monitor their relative health. The sensor takes a measurement at one point, shifts over a bit, and takes another measurement. This approach yields rapid feedback about concentration changes. You can read more in "New method monitors critical bacteria in wastewater treatment" in the Genetic Engineering & Technology News.
A Green(er) Current Sensor
Fiber-optic sensors aren't just useful for distributed temperature and strain measurements, they can also be used to monitor current and voltage of power lines. Jim Blake, currently at NxtPhase, invented the technology when he was an associate professor of electrical engineering at Texas A&M University. Now, Texas A&M has licensed the technology to a French utility company, Areva, to measure current and voltage in electrical substations. Because the sensor is fiber-optic based, it doesn't present the same environmental problems as the more traditional, oil-filled monitoring technologies.
Bolstering Busted Knees
Knees are tricky things. They take a great deal of punishment during daily use and, if injured, take a long time to heal. But by using a tiny radio transmitter coupled to a load sensor, professor John Szivek from the University of Arizona Department of Orthopedic Surgery, plans to track how an injured knee is doing. Specifically, he and his team want to monitor how well re-growing cartilege is doing. According to Szivek, quoted in the article "Transmitter may help regenerate cartilage" from the Daily WildCat, "We want to be able to rehabilitate patients in some reasonable and intelligent way. To do that, we need to be able to know what kind of loads to put on their knees while their tissue is growing." The study also involves the use of stem cells from fat to help grow cartilege tissue. (Editor's note: Instrumenting knees so you can repair them and track their healing progress? Bring it on!)