Malini Guha: Worth watching
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Those unlucky enough to be saddled with a loud snoring partner will rest more easily knowing that researchers are working on new ways to help them catch some more ZZZs.
Gerald Loeb, heading a team at the Alfred Mann Institute for Biomedical Engineering at the University of Southern California (USC) is hoping to use his patented “BION” technology to prevent snoring.
The BION is a miniature electrical stimulator the size of a grain of rice, which can be injected into muscles in the body. It receives its commands wirelessly through a microprocessor programmed with specific instructions located outside of the body.
One version of the technology was approved last year in Europe to treat urinary incontinence. Other versions are being studied in patients who have suffered a stroke or have arthritis or are partially paralysed.
Snoring occurs when the soft palate and the uvula - the skin tissue that hangs down in the back of the throat - vibrate during breathing. The unpleasant noise comes from efforts to force air through the passageway that has been narrowed due to some obstruction or blockage, such as fat in the throat area or the tongue falling into the throat. When awake, the snorer has control of the muscles to tense and shape the passageway to prevent the vibrations, but during sleep loses control of these.
The BION, or implanted microstimulator, would work by causing at least one muscle to contract to reduce the vibrations of the airway passage. Multiple microstimulators could be implanted via a needle to stimulate different muscles, and a specific pattern of pulses could be programmed into a chip located in a small device that could be placed by the bed. The power and command signals are transmitted to the microstimulators by a radio frequency magnetic field via a flat coil of wire placed under one’s pillow.
The procedure to implant the device is not painful, only takes about 15-30 minutes, and would only be need to be done once in one’s life, says Prof Loeb. This compares favourably with surgical tissue removal, which is not only more cumbersome but may need to be repeated as tissue often grows back, says Prof Loeb. Less complex implants such as plastic stiffeners are under investigation but these do not provide the flexibility to adjust the treatment if the snoring returns, while the stimulation from the BIONs can be reprogrammed at any time, he adds.
However, the researchers’ main challenge is to identify in each individual patient which tissue in the airway is vibrating when one is sleeping and which muscle or muscles need to be stimulated to tense or pull these structures in which direction to make the snoring stop.
It also must be determined whether constant delivery of pulses throughout the night is most effective, versus activating the implants only when a nearby microphone detects the snoring.
The device, which Prof Loeb also hopes to use to treat some forms of sleep apnea, has not yet reached clinical trials for snoring. The researchers first need to develop methods to identify in each patient which tissues are implicated in the snoring and which muscles need to be tensed.
Light-weight carbon fiber cars
“America is addicted to oil,” famously proclaimed President Bush in his most recent State of the Union address.
While driving less would mitigate the craving, most Americans would prefer to have their cake and eat it too.
One project funded by the Department of Energy is hoping to help achieve this by developing cheaper processes to make cars from lightweight carbon fibre composites that use significantly less fuel than cars made of steel.
Replacing half of the steel with carbon fibre composites could reduce a vehicle’s weight by 60 percent and fuel consumption by 30 percent, according to some DoE studies. This, of course, would also help significantly reduce worldwide greenhouse gas emissions that lead to global warming, since the motor industry is responsible for about a quarter of these.
Carbon fibre, which is itself one-fifth the weight of steel but just as stiff and strong, is already used in racecars and a few parts of some cars seen on highways. However, it is too expensive to be more widely utilised.
The Department of Energy’s Oak Ridge National Laboratory is looking to bring down the cost of the carbon fibre from between $8 and $10 per pound to between $3 and $5 per pound, a price at which project leader Bob Norris says the cars would be competitive in cost with those made of steel. The carbon fibre will be blended with plastics that hold it together.
Mr Norris says that there are two main ways his team is looking at reducing the cost of carbon fibre by using cheaper precursors to produce it and cheaper processes to convert those precursor materials into carbon fibre. One of the precursors the team is considering is an alternative form of an acrylic or polyacrylonitrile (PAN) that costs significantly less than the PAN used to make carbon fibre today, while the other is a lignin from wood pulp, a renewable source. Although bulk lignin is potentially even cheaper, says Mr Norris, the researchers have to find a way to cost-effectively spin it into a suitable fibre form that can be converted into carbon fibre with appropriate properties.
Once the PAN or lignin is produced, it has to be converted into carbon fibre. Today’s methods involve passing it slowly through an oven of high-temperature and controlled atmosphere where it undergoes oxidation, carbonization, and other processing to burn off the other elements leaving essentially a very still and strong carbon structure, says Mr Norris. Instead, his team is looking to convert the precursor by passing it through a plasma, or ionized gas field. This could significantly speed up the conversion processing allowing faster production at lower cost.
The team has demonstrated that these advanced processing methods can be done on a small scale, but now has to show that it can be done on the sort of scale needed for mass manufacturing.
Making light-weight cars that use less fuel is just one way to reduce oil consumption by autos. Another way is to use renewable sources of energy as fuel, the subject of much research. Mr Norris says the two are complementary. For instance, cars using hydrogen fuel cells will require light-weight structures in order to have the range between refuelling that the consumer expects.
Microwave breast cancer detection
Mammography is generally not useful for younger, pre-menopausal women, unless they have a family history of breast cancer, because their breast tissue is generally denser, making it difficult for the X-rays used to detect tumours. At the same time, like any ionizing radiation, X-rays can be harmful, actually increasing the chance of cancer with repeated use over time.
Researchers are now hoping to use much lower energy, non-ionizing microwaves to screen for breast cancer instead. Not only would microwaves not be harmful, says Roy Johnson, chief executive of Micrima, a spin-out from Bristol University that is developing a microwave-based device originally developed for detecting buried landmines, but they can better image dense tissue. The reasons are that they have a higher contrast between different tissues and generate a 3-dimensional rather than 2-dimensional image.
Magnetic Resonance Imaging (MRI) scans also give a 3-dimensional image and can see equally deep into tissue. However, they are very expensive and therefore not used for screening as is X-ray mammography. Mr Johnson is expecting a microwave based device to be at least 10 times cheaper than even X-ray mammography equipment, as it will be much smaller, cheaper to build and require far less running costs. The ultimate goal is to make it so affordable that it could be in every GP surgery, so that a woman need not go to the hospital or special clinic for a routine screen.
Microwaves work by measuring the complex permittivity, which is different between normal breast tissue and cancerous breast tissue. Breast tissue is unique amongst human tissues in having a very low permittivity, says Mr Johnson, so the technology is unlikely to be effective in detecting tumours in other parts of the body. Complex permittivity is made up of the dielectric constant determined largely by the water content, and by the conductivity which comes from the water, salts and from the state of different proteins in the tissue.
Detecting small lumps in the breast is a conceptually similar problem as detecting buried landmines, but one that requires the use of higher microwave frequencies, says Mr Johnson. The approach used by Micrima also exploits a number of microwave antennas, called an “array,” and in laboratory trials this technique has already been able to find tumours as small as 4mm diameter - approaching the limit of X-ray detection.
The other challenge in using microwaves to generate images within the body is that skin is a reflector of microwaves. Micrima’s technology overcomes this hurdle by knowing where the skin is and rejecting the signal, at the same time employing a layer that cancels much of the reflections from the skin – similar to the coating on a camera lens.
The researchers are still working on optimising the technology and are currently completing the development a prototype clinical device in order to start full clinical trials within the next couple of months.
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