- The Washington Times - Wednesday, December 27, 2006

An inebriated driver may fool some of the police some of the time but not a breathalyzer.

Breath-alcohol detectors, whether they’re wielded by a state official or a would-be driver, can determine whether someone deserves to be behind the wheel or on the side of the road hailing a taxi.

In all 50 states, as well as Puerto Rico and the District, a person is considered to be driving under the influence if he or she has a .08 percent or higher blood alcohol content (BAC).

The devices work because of the way the human body takes in, and processes, alcohol. People can smell alcohol on a person’s breath for a reason. The alcohol is processed quickly in the body, and the results can be measured a mere 15 minutes or so later.

Robert F. Borkenstein, a former Indiana state trooper and professor at Indiana University, is credited with inventing the first blood alcohol detector in 1954.

Today, these devices use two main technologies to measure inebriation.

Ed Gollar, managing director of Cincinnati-based OmegaPoint Systems, which produces BreathKey, says people coming out of a bar have no idea the level of alcohol in their bodies.

“So many factors can affect your blood alcohol level,” says Mr. Gollar, who once worked for a firm that created court-ordered breath testers in cars, called ignition interlocks, for convicted drunken drivers.

“One person might have a couple of drinks and be at one level, and the same person on a different day can have a different level,” he says, depending on the amount of sleep that person has had or how much he or she ate over a certain period.

OmegaPoint Systems’ BreathKey is portable and uses a fuel-cell sensor to measure inebriation.

Mr. Gollar says devices started to include fuel cells about a decade ago. Before that, the detectors used semiconductors to measure BAC.

A fuel-cell detector “acts more like a small battery,” he says. The presence of alcohol generates a small, measurable electric charge.

With semiconductor models, the detector must first be heated up and then the presence of ethanol changes the electrical resistance within.

“A microprocessor measures that resistance,” Mr. Gollar says.

Portable BAC detectors help people know if their intoxication level could lead to an arrest, but the technology isn’t perfect at the consumer level.

“All breathing equipment has inherent inaccuracies in it,” Mr. Gollar says.

A Department of Transportation device is generally accurate to the one-thousandth of a unit of measurement, while a BreathKey is accurate to the one-hundredth of a unit.

Alcohol’s effect on the body depends on the body in question.

Dr. Stephen W. Peterson, chairman of the department of psychiatry at Washington Hospital Center in Northwest, says individual body types can affect how someone tolerates drinking.

“The larger the body, the more you can tolerate a drug,” Dr. Peterson says, “but even a very large person can get drunk very quickly.”

No matter a person’s size, alcohol is processed the same way biologically.

“As soon as alcohol is absorbed, it goes into the bloodstream and into the liver,” Dr. Peterson says.

Dr. Jennifer Mills, an internal medicine resident at the hospital, adds that a drinker will have elevated concentrations of alcohol in his or her blood and breath because the “lungs are an extremely vascular system.”

“The alveoli [in the lungs] are surrounded by blood vessels, so there is lots of blood going through the lungs,” she says.

Blood alcohol detectors don’t require any specific knowledge, which is a good thing, given the complexities surrounding the matter.

Keith Nothacker, president and owner of San Francisco-based KHN Solutions, which distributes and sells blood alcohol detectors, says intoxication “is a somewhat objective thing in terms of feeling, but your blood alcohol number is an exact number.”

A person could feel fine but still be impaired. That is particularly true with alcoholics, Mr. Nothacker says.

“It’s much better to test yourself before you go out,” he says.

That test should be done carefully.

A user should wait at least 15 minutes after eating or drinking before blowing into a detector, Mr. Nothacker says.

“Any alcohol in the mouth will throw off the reading,” he cautions.

The minds behind ignition-interlock devices, used when the courts order drunken drivers to test their breath before starting their cars, create a number of steps to make sure their products read BAC accurately.

Ignition-interlock devices work by cutting a car’s power if the user blows into a device that measures his or her BAC and alcohol is detected.

Jim Ballard, president of Smart Start in Irving, Texas, says companies like his that produce ignition-interlock systems have means to prevent drivers from beating the technology.

Some devices require the driver to retest, to blow into the system again while the car is moving. A positive test is then recorded, and the information is given to the proper authorities.

Others require a humming sound to trigger the test, which prevents a person from using compressed air to avoid using his or her own breath.

Smart Start is beginning a new version of its system, which will include a digital camera that will snap a picture when someone blows into the hand-held unit.

The future for ignition interlocks is beneath the skin.

Mr. Ballard says researchers are working on a system that doesn’t require a breath test. The future may see devices that read BAC levels by touch.

“They will read through the skin, a transdermal type of application. That’s where we think you have to go to get the best reading,” he says.

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