[size=+1]The electronic fink that will squeal if you drink[/size]
04 December 2009 by Jim Giles
Magazine issue 2737.
MEMORIAL day weekend 2007 is one that Lindsay Lohan might rather forget. An actor better known for her off-screen antics than her starring roles, Lohan crashed her Mercedes in Santa Monica, California, while over the legal alcohol limit. She checked into rehab. A month-and-a-half later, in July, Lohan emerged and declared that she would clean up her act. Within days she was again caught driving while over the limit.
This celebrity story has a twist, however. As part of her efforts to stay sober, Lohan wore an alcohol-monitoring anklet. When photos of her wearing the anklet hit the press, it was the first time many people had heard of such a thing. Yet devices like these are transforming the way alcohol offenders are dealt with in the US.
"In the past we've said that if you don't stop drinking and driving, we'll stop you from driving," says Bill Mickelson, who has worked with the devices as part of a sobriety programme in South Dakota. "That never got to the heart of the problem. So we've developed a way to stop you drinking."
Lohan wore her anklet voluntarily, but most wearers have no choice if they wish to avoid jail. So in the not-too-distant future, could you find yourself wearing such a device if you misbehave after having a few too many? Is this the first step towards a Big Brother age even more intrusive than that envisaged by George Orwell, where the authorities are automatically alerted whenever you consume any substance deemed undesirable? And is this kind of monitoring reliable?
Traces of most drugs linger in our bodies for days or weeks, so random tests every few days can detect most use. Alcohol, however, leaves the body so quickly that tests would have to be done more than once a day to be sure of detecting any drinking. Hence the need for the device Lohan wore, called a secure continuous remote alcohol monitor, or SCRAM.
It relies on the fact that about 1 per cent of any alcohol we consume leaves the body through the skin. Once an hour, it fires a soft jet of air at the skin, vaporising any alcohol present and measuring its concentration. Every night, the day's readings are relayed to the company that makes the anklets, Alcohol Monitoring Systems of Littleton, Colorado, via a modem installed in the wearer's home. If it appears that an individual has been drinking, AMS notifies the relevant official.
Over the past six years, use of the anklets has spread to almost every part of the US. The courts there have the power to place someone convicted of drunk-driving or alcohol-related violence on probation and require that they abstain from drinking, rather than send them to jail. Judges can also make SCRAM use a condition of bail.
Wearing a monitor is a small price to pay for being able to stay at home with your family and go to work as usual, rather than go to jail. It is also cheaper: SCRAM costs about $12 per person per day, compared with about $60 to keep someone locked up.
These advantages have led to the rapid adoption of SCRAM across the US since its introduction in 2003: over 110,000 people have worn the anklets and about 10,000 are currently being monitored.
Some wearers try to beat the system by placing a barrier between the anklet and their skin, or by removing it altogether, but tampering can be detected. The monitor is fitted with an infrared sensor whose readings change abruptly if objects are placed underneath it, while a temperature sensor triggers an alert if it appears the anklet has been removed from the skin.
Wearers often complain that the device is uncomfortable and looks embarrassing. But beyond that the ankle monitors do not cause any serious problems, says AMS spokesperson Kathleen Brown. They can be worn in the bath and while running or driving, though they can interfere with sports such as soccer.
AMS says that over 70 per cent of SCRAM users do not violate the terms of their probation or bail, which suggests that the device is helping to reduce drinking and by extension alcohol-related crimes. No rigorous, randomised trials have been carried out to confirm this, but what evidence there is appears positive. In 2005, for instance, South Dakota launched its 24/7 sobriety programme, under which judges can order offenders or those on bail not to drink or take drugs. While other states have similar programmes, South Dakota broke new ground by forcing those on the scheme to submit to round-the-clock monitoring using, among others, SCRAM, breath and urine tests. Although it is not possible to separate the effect of SCRAM from the other forms of testing used, the overall impact has been impressive: alcohol-related accidents and injuries have fallen by 43 per cent in the state over the last three years.
Amid the chorus of approval, however, there are a few dissenting voices. Ever since the anklet was introduced, a few wearers have claimed that the device produces false positives: alerts for drinking sessions that never happened.
The SCRAM's sensor detects the pair of oxygen and hydrogen atoms, called a hydroxyl group, characteristic of all alcohols. This means it cannot discriminate between ethanol and other forms of alcohol. Many common household substances, such as cleaning fluids and perfume, contain alcohol, which can get into the gap between the detector and skin to produce a false reading.
AMS, however, insists that it can differentiate between external contamination and drinking. Suspicious readings are automatically flagged up by computer at the AMS offices. The company's customer service team takes a look and, if the readings seem ambiguous, sends them to Jeffrey Hawthorne, co-founder of AMS, and a colleague of his for confirmation. Hawthorne would not tell New Scientist exactly how they make that call, but says the process is based on the fact that external contaminants, such as perfume, build up on and evaporate from the skin more rapidly than ethanol from drinking.
When someone wearing a SCRAM starts drinking, Hawthorne says, the estimated blood alcohol concentration readings will rise by less than 0.05 percentage points per hour (see graph). When the wearer stops drinking, readings fall at less than 0.025 percentage points per hour. More rapid changes must be due to a contaminant, he claims.
Paige Lustig is just one of several people to disagree. One morning in February 2006, Lustig arrived for a modelling assignment at a hair salon in Birmingham, Alabama. She was on probation for drunk-driving and was wearing a SCRAM. Just after 1 pm, when she left the salon to go home, the device recorded a build-up of alcohol. Lustig found herself back in court facing a jail term.
Alcohol does not appear on the skin until 1 to 2 hours after consumption begins, so the readings suggested that Lustig started drinking in the middle of her modelling job. Lustig insists this did not happen. Salvatore Rino Marra, the salon's owner, told the probation hearing that he never allows alcohol in his salon. His wife, and one of the other stylists present that morning, also said that Lustig had not been drinking.
Marra and his wife had applied shampoo, gel, conditioner and large amounts of hair spray to Lustig's hair, compounds that often contain alcohol. Lustig's hair was also blown dry. It is possible that the air in the salon that morning contained enough alcohol to trigger the SCRAM, Michael Hlastala, an expert in the physiology of alcohol at the University of Washington in Seattle, told the court.
Hlastala is a critic of the SCRAM and has testified in around a dozen cases involving the device. He accepts that contaminants generally build up and decay more rapidly than alcohol from drinking, but claims SCRAM data is often so noisy that it is not always possible to distinguish between the two. "It's very hard to identify curves caused by these chemicals," he warns.
Lustig's probation violation was dismissed by the judge, largely on the basis of the eyewitness accounts. AMS would not comment on the case, but the company acknowledges that mistakes are possible, if rare. Brown says that AMS runs internal monthly tests using at least 10 volunteers. Each wears a SCRAM anklet and keeps a log of their activities, including drinking. "We recruit people from hair salons, auto shops, construction sites, bars," she says. Over 12 years of testing, the false positive rate is running at 0.12 per cent. This figure suggests about 1 in 800 of the alerts issued to authorities by AMS is incorrect.
There is little independent research on the SCRAM, but what there is does not contradict AMS's internal findings. In one study, Paul Marques and Scott McKnight of the Pacific Institute for Research and Evaluation in Calverton, Maryland, checked the readings produced when 22 volunteers wearing SCRAMs drank, both in the lab and at home and in bars, over two to four weeks. The device detected 88 per cent of drinking episodes that raised blood-alcohol concentrations above 0.08 per cent - the limit for driving in many countries including the US and UK - with zero false positives (Alcoholism: Clinical and Experimental Research, vol 33, p 703).
Despite the small size of the study, its results have been used with great success to defend against court challenges to the SCRAM. Only a handful of alerts appear to have been overturned in court, New Scientist's research suggests, despite the fact that at least several tens of alerts must have been false positives.
Marques thinks AMS should notify SCRAM wearers immediately if a positive result is registered. That way, anyone who thinks the alert is a false positive might have time to take a breath or urine test. "If it's going to affect someone's freedom then we need confirmation," Marques says. In practice this could be difficult, as readings can only be sent to AMS when people are within range of the modem in their home. AMS, for its part, says it is up to the courts to decide if people should have the right to a back-up test.
For now, the company is focusing on the US market, and New Scientist found that few officials in other countries knew much about its alcohol monitors. The UK's Department of Transport says it has not looked at this kind of device, for instance. Introducing them could be tricky in many countries, because few have the legal power to stop people drinking altogether. In Australia, for instance, offenders can be banned from entering bars but not from drinking elsewhere.
Future monitors, however, could make it possible to detect more specific activities, such as driving while under the influence. L3 Communications of Canton, Massachusetts, has developed an anklet that can detect the characteristic patterns of acceleration and deceleration generated by the motion of a car, and the movement of a driver's foot on and off the pedals.
The anklet identified when people were driving with 100 per cent accuracy during internal testing, says Leroy Collins, a member of the development team. L3 designed the device for use with people who have had their driving licence suspended, but several companies are now developing rival alcohol monitors after AMS's success and some are interested in incorporating L3's technology.
Some people will think that this kind of monitoring is a step too far. But as long as it helps keep people off drink or off the road, and out of jail, it is likely to attract more supporters than critics. Even researchers concerned about the lack of rigorous, large-scale studies say the benefits of AMS's device justify its use. "I'm sceptical about the science," says Arthur Lurigio, who studies criminal justice and health at Loyola University in Chicago. "But I welcome the SCRAM because it helps people avoid jail and the stigma of jail."
Link: http://www.newscientist.com/article...ronic-fink-that-will-squeal-if-you-drink.html
04 December 2009 by Jim Giles
Magazine issue 2737.
MEMORIAL day weekend 2007 is one that Lindsay Lohan might rather forget. An actor better known for her off-screen antics than her starring roles, Lohan crashed her Mercedes in Santa Monica, California, while over the legal alcohol limit. She checked into rehab. A month-and-a-half later, in July, Lohan emerged and declared that she would clean up her act. Within days she was again caught driving while over the limit.
This celebrity story has a twist, however. As part of her efforts to stay sober, Lohan wore an alcohol-monitoring anklet. When photos of her wearing the anklet hit the press, it was the first time many people had heard of such a thing. Yet devices like these are transforming the way alcohol offenders are dealt with in the US.
"In the past we've said that if you don't stop drinking and driving, we'll stop you from driving," says Bill Mickelson, who has worked with the devices as part of a sobriety programme in South Dakota. "That never got to the heart of the problem. So we've developed a way to stop you drinking."
Lohan wore her anklet voluntarily, but most wearers have no choice if they wish to avoid jail. So in the not-too-distant future, could you find yourself wearing such a device if you misbehave after having a few too many? Is this the first step towards a Big Brother age even more intrusive than that envisaged by George Orwell, where the authorities are automatically alerted whenever you consume any substance deemed undesirable? And is this kind of monitoring reliable?
Traces of most drugs linger in our bodies for days or weeks, so random tests every few days can detect most use. Alcohol, however, leaves the body so quickly that tests would have to be done more than once a day to be sure of detecting any drinking. Hence the need for the device Lohan wore, called a secure continuous remote alcohol monitor, or SCRAM.
It relies on the fact that about 1 per cent of any alcohol we consume leaves the body through the skin. Once an hour, it fires a soft jet of air at the skin, vaporising any alcohol present and measuring its concentration. Every night, the day's readings are relayed to the company that makes the anklets, Alcohol Monitoring Systems of Littleton, Colorado, via a modem installed in the wearer's home. If it appears that an individual has been drinking, AMS notifies the relevant official.
Over the past six years, use of the anklets has spread to almost every part of the US. The courts there have the power to place someone convicted of drunk-driving or alcohol-related violence on probation and require that they abstain from drinking, rather than send them to jail. Judges can also make SCRAM use a condition of bail.
Wearing a monitor is a small price to pay for being able to stay at home with your family and go to work as usual, rather than go to jail. It is also cheaper: SCRAM costs about $12 per person per day, compared with about $60 to keep someone locked up.
These advantages have led to the rapid adoption of SCRAM across the US since its introduction in 2003: over 110,000 people have worn the anklets and about 10,000 are currently being monitored.
Some wearers try to beat the system by placing a barrier between the anklet and their skin, or by removing it altogether, but tampering can be detected. The monitor is fitted with an infrared sensor whose readings change abruptly if objects are placed underneath it, while a temperature sensor triggers an alert if it appears the anklet has been removed from the skin.
Wearers often complain that the device is uncomfortable and looks embarrassing. But beyond that the ankle monitors do not cause any serious problems, says AMS spokesperson Kathleen Brown. They can be worn in the bath and while running or driving, though they can interfere with sports such as soccer.
AMS says that over 70 per cent of SCRAM users do not violate the terms of their probation or bail, which suggests that the device is helping to reduce drinking and by extension alcohol-related crimes. No rigorous, randomised trials have been carried out to confirm this, but what evidence there is appears positive. In 2005, for instance, South Dakota launched its 24/7 sobriety programme, under which judges can order offenders or those on bail not to drink or take drugs. While other states have similar programmes, South Dakota broke new ground by forcing those on the scheme to submit to round-the-clock monitoring using, among others, SCRAM, breath and urine tests. Although it is not possible to separate the effect of SCRAM from the other forms of testing used, the overall impact has been impressive: alcohol-related accidents and injuries have fallen by 43 per cent in the state over the last three years.
Amid the chorus of approval, however, there are a few dissenting voices. Ever since the anklet was introduced, a few wearers have claimed that the device produces false positives: alerts for drinking sessions that never happened.
The SCRAM's sensor detects the pair of oxygen and hydrogen atoms, called a hydroxyl group, characteristic of all alcohols. This means it cannot discriminate between ethanol and other forms of alcohol. Many common household substances, such as cleaning fluids and perfume, contain alcohol, which can get into the gap between the detector and skin to produce a false reading.
AMS, however, insists that it can differentiate between external contamination and drinking. Suspicious readings are automatically flagged up by computer at the AMS offices. The company's customer service team takes a look and, if the readings seem ambiguous, sends them to Jeffrey Hawthorne, co-founder of AMS, and a colleague of his for confirmation. Hawthorne would not tell New Scientist exactly how they make that call, but says the process is based on the fact that external contaminants, such as perfume, build up on and evaporate from the skin more rapidly than ethanol from drinking.
When someone wearing a SCRAM starts drinking, Hawthorne says, the estimated blood alcohol concentration readings will rise by less than 0.05 percentage points per hour (see graph). When the wearer stops drinking, readings fall at less than 0.025 percentage points per hour. More rapid changes must be due to a contaminant, he claims.
Paige Lustig is just one of several people to disagree. One morning in February 2006, Lustig arrived for a modelling assignment at a hair salon in Birmingham, Alabama. She was on probation for drunk-driving and was wearing a SCRAM. Just after 1 pm, when she left the salon to go home, the device recorded a build-up of alcohol. Lustig found herself back in court facing a jail term.
Alcohol does not appear on the skin until 1 to 2 hours after consumption begins, so the readings suggested that Lustig started drinking in the middle of her modelling job. Lustig insists this did not happen. Salvatore Rino Marra, the salon's owner, told the probation hearing that he never allows alcohol in his salon. His wife, and one of the other stylists present that morning, also said that Lustig had not been drinking.
Marra and his wife had applied shampoo, gel, conditioner and large amounts of hair spray to Lustig's hair, compounds that often contain alcohol. Lustig's hair was also blown dry. It is possible that the air in the salon that morning contained enough alcohol to trigger the SCRAM, Michael Hlastala, an expert in the physiology of alcohol at the University of Washington in Seattle, told the court.
Hlastala is a critic of the SCRAM and has testified in around a dozen cases involving the device. He accepts that contaminants generally build up and decay more rapidly than alcohol from drinking, but claims SCRAM data is often so noisy that it is not always possible to distinguish between the two. "It's very hard to identify curves caused by these chemicals," he warns.
Lustig's probation violation was dismissed by the judge, largely on the basis of the eyewitness accounts. AMS would not comment on the case, but the company acknowledges that mistakes are possible, if rare. Brown says that AMS runs internal monthly tests using at least 10 volunteers. Each wears a SCRAM anklet and keeps a log of their activities, including drinking. "We recruit people from hair salons, auto shops, construction sites, bars," she says. Over 12 years of testing, the false positive rate is running at 0.12 per cent. This figure suggests about 1 in 800 of the alerts issued to authorities by AMS is incorrect.
There is little independent research on the SCRAM, but what there is does not contradict AMS's internal findings. In one study, Paul Marques and Scott McKnight of the Pacific Institute for Research and Evaluation in Calverton, Maryland, checked the readings produced when 22 volunteers wearing SCRAMs drank, both in the lab and at home and in bars, over two to four weeks. The device detected 88 per cent of drinking episodes that raised blood-alcohol concentrations above 0.08 per cent - the limit for driving in many countries including the US and UK - with zero false positives (Alcoholism: Clinical and Experimental Research, vol 33, p 703).
Despite the small size of the study, its results have been used with great success to defend against court challenges to the SCRAM. Only a handful of alerts appear to have been overturned in court, New Scientist's research suggests, despite the fact that at least several tens of alerts must have been false positives.
Marques thinks AMS should notify SCRAM wearers immediately if a positive result is registered. That way, anyone who thinks the alert is a false positive might have time to take a breath or urine test. "If it's going to affect someone's freedom then we need confirmation," Marques says. In practice this could be difficult, as readings can only be sent to AMS when people are within range of the modem in their home. AMS, for its part, says it is up to the courts to decide if people should have the right to a back-up test.
For now, the company is focusing on the US market, and New Scientist found that few officials in other countries knew much about its alcohol monitors. The UK's Department of Transport says it has not looked at this kind of device, for instance. Introducing them could be tricky in many countries, because few have the legal power to stop people drinking altogether. In Australia, for instance, offenders can be banned from entering bars but not from drinking elsewhere.
Future monitors, however, could make it possible to detect more specific activities, such as driving while under the influence. L3 Communications of Canton, Massachusetts, has developed an anklet that can detect the characteristic patterns of acceleration and deceleration generated by the motion of a car, and the movement of a driver's foot on and off the pedals.
The anklet identified when people were driving with 100 per cent accuracy during internal testing, says Leroy Collins, a member of the development team. L3 designed the device for use with people who have had their driving licence suspended, but several companies are now developing rival alcohol monitors after AMS's success and some are interested in incorporating L3's technology.
Some people will think that this kind of monitoring is a step too far. But as long as it helps keep people off drink or off the road, and out of jail, it is likely to attract more supporters than critics. Even researchers concerned about the lack of rigorous, large-scale studies say the benefits of AMS's device justify its use. "I'm sceptical about the science," says Arthur Lurigio, who studies criminal justice and health at Loyola University in Chicago. "But I welcome the SCRAM because it helps people avoid jail and the stigma of jail."
Link: http://www.newscientist.com/article...ronic-fink-that-will-squeal-if-you-drink.html