6 ms·

Developing a viable cannabis breathalyzer

28 points by newman8r 8y ago

hirundo 8y ago
Why use less reliable proxies like breathalizers to gauge impairment when we now have the technology to measure it far more directly: convert traffic cop cars into mobile virtual reality driving simulators. Put a gaming laptop in the trunk, and the DWI suspect behind the wheel with a VR headset on and let them drive through a couple of minutes of reasonably challenging simulated traffic. Let software come up with an objective score and store the simulated session as evidence if they fail. Not only does this more directly measure impairment, it catches any cause of it, not just a particular substance. Virtual driving impairment will correlate with real driving impairment far better than parts per million of a molecule in the bloodstream.
- deleted 8y ago
  [deleted]
- RobLach 8y ago
  Very difficult to prove that the simulation is an accurate and easy to grasp representation that holds up in a court.
  - hirundo 8y ago
    You could put the judge and/or jury in VR headsets for the playback. They would see just what the defendant saw, in four dimensions. That's amazingly high fidelity, and the chain of evidence can be demonstrated with a checksum. Compared to judging the inner workings of a breathalyzer, that pretty good.
    - bdcravens 8y ago
      All that proves is they failed a simulation, not that they were under the influence. Burden of proof lies with the prosecution.
      - hirundo 8y ago
        Seems like we should care more about driving impaired than about driving under the influence. The former is what we're trying to prevent by policing the later. You can be impaired without being under the influence, and under the influence without being significantly impaired.
        bdcravens 8y ago
        I don't disagree, but I've had moments when I was a terrible driver: I was tired, I was pissed off, I was stressed, I had just received bad news, I was quitting nicotine, etc.
        hirundo 8y ago
        I've done that too, and I should have been busted for that too. Is it really better to risk other lives due to lack of sleep than from too many drinks? For some stranger's little kid in another car's back seat, impaired is impaired.
        bdcravens 8y ago
        By that standard, that stranger could be arrested for careless driving because the child in their back seat was screaming for a juice box and they were allowing themselves to be distracted.
        hirundo 8y ago
        Failure to control a vehicle is a violation in the places I've lived. It applies regardless of circumstances. Ice patch, animal runs in front, screaming toddler, whatever the cause, you can still be arrested for it.
        bdcravens 8y ago
        In which case you need no VR setup, as the event happened prior to the officer interaction. Most of what you described is a ticket, not an arrestable offense.
- corndoge 8y ago
  "You suck at video games, enjoy your DUI" Honestly this sounds unreasonable.
- pmichaud 8y ago
  It's an interesting idea, but the critical issue with it is that it's not illegal to be bad at driving. That could change, but that's how it is now.
  - nerfhammer 8y ago
    Ah, but it's illegal to drive without a license and the test is a de facto driving test so you could make it so that if you fail it you won't get arrested but you get your license suspended on the spot.
    - bdcravens 8y ago
      Currently simulations aren't valid driving tests, so that entire section of law would have to change. Moreover, does any state do on-demand driving tests? Typically you set the appointment, not the state. Additionally Texas (I'm sure other states are similar) doesn't even "suspend on the spot" for DWIs (you have 40 days or more from the incident before the suspension is effective).
  - mavhc 8y ago
    It'll illegal to drive dangerously though, surely. It's a test that removes the license to drive from those who can't drive properly, whether due to old age, eyesight, drugs, tiredness. Only self driving cars for you.
    - bdcravens 8y ago
      The tests for obtaining a license allow for multiple attempts, and are administered by officers trained for that job, and aren't based on a video game installed in a cruiser. > It'll illegal to drive dangerously though, surely. Yes, and for all but the worst offenses (say, 30+ miles over the speed limit) the penalty is merely a fine and points against your license.
  - mjfl 8y ago
    If someone drives as if they are drunk, all the time, then I don't think they should have a license as they are clearly a danger to public health. On a similar note, the driving test for a license could include a run in the simulator to both test driving skills and establish a baseline for the test. Then the impairment could be measured as relative to that baseline. I think it's a good idea.
- bdcravens 8y ago
  You're describing a fancy field sobriety test. There's a reason why those who fail field sobriety tests for alcohol are then asked for a breath sample (or when they refuse, a blood test) A criminal defense lawyer would tell their clients to say in court they intentionally failed the test. (Burden of proof still lies with the prosecution) You can't be convicted for failing a test. You can only be convicted of being under the influence.
  - nasredin 8y ago
    I read something (a legit study IIRC) that breathalyzers are not that accurate and if you don't hold them right can increase the BAC. And NO you CAN be convicted for failing the test. The evidence is just a paper reciept from the breathalyzer. The reason you choose the blood test is so you have evidence for later. Also you will sober up a little while you wait.
    - bdcravens 8y ago
      To be clear, I mean no one is being convicted of failing a field sobriety test with no breathalyzer or blood BAC results.
  - thebigspacefuck 8y ago
    I believe there was a case in Colorado where a medical Marijuana user had enough THC in their blood to be considered impaired but they were able to pass a field sobriety test so they weren't convicted of a DUI. The problem is that the amount of THC you need in your blood to impair you is different for every person so it's hard to develop a test for it. A driving simulator makes sense to me, though once you have a bunch of adrenaline kicking in and are totally focused on not going to jail, you may perform better than when you are relaxed in the comfort of your own car.
- bequanna 8y ago
  I have no idea legally how this would work, but is 'proving' impairment using your proposed method enough? I would think the missing piece would still be linking impairment to a substance or condition that the driver knew about, but drove anyway. ...which is why a simple sobriety test is typically given before a Breathalyzer.
  - hirundo 8y ago
    We should care more about getting incapable drivers to stop driving than detecting insobriety. We should want safety police, not morality police. And strictly on the morality angle, I don't think driving drunk is more culpable than driving over tired or over angry. I find those things are about as easy to detect in myself as drunkenness.
- jotm 8y ago
  Aside from the other issues, how do you expect your average police officer to handle that thing? You know they're not exactly the brightest people, right?
  - mindslight 8y ago
    You tell the cop there's a problem with the simulator. He sits down. You point out that other driver just ran a red light. He gives chase on the simulator. You walk away. Sorted.
- codeulike 8y ago
  producer of Black Mirror bookmarks this comment
scarface74 8y ago
It couldn’t be any worse than “specially trained officers” who are able to detect whether someone is high by thier mannerisms and arrest people who aren’t using anything. https://www.11alive.com/article/news/investigations/the-drug-whisperer-drivers-arrested-while-stone-cold-sober/85-437061710 https://www.11alive.com/article/news/investigations/the-drug...
- eeeeeeeeeeeee 8y ago
  Exactly. The article even says as much. It simply detects if someone smoked something with THC in the last two hours. So there is no consideration for actual impairment? My bullshit detector went off when the creator of the device said "this device has a lot of science in it."
  - singingfish 8y ago
    Cannabis detection devices in Australia (NSW anyway, maybe VIC and other states) seem to have a detection window of a couple of days or more. So it's almost entirely moral policing operational over here. This would be an improvement on that.
  - mchahn 8y ago
    My bullshit detector went off when the article said "the number of drivers involved in fatal crashes who tested positive for marijuana is up significantly" (a reference to Colorado). Duh, the overall percentage of the population smoking dope went up when legalized.
- NikolaNovak 8y ago
  That article is completely terrifying. * I am much too much of a control freak to ever ever try drugs; no moral issue, just not for me. * I have a drink of something on social occasion maybe once or twice a year, maybe not. Never got behind the wheel with even a sip of alcohol that day, let alone a glass, let alone anything approaching legal limit. But I'm a klutz and I'm an introvert and I get nervous easily and I have NO idea what kind of "signs" my body would display in stressful situation with a police officer at night (my body an my brain have an uneasy working relationship - we mostly put up with each other:). It is very literally my nightmare scenario to be accused by a police officer of intoxication where none exists. As much as I 100% support them, I'm probably more afraid of roadside checks than an actually inebriated person.
ohiovr 8y ago
I would like to know how this works. THC is an oil or resin. For it to appear in your breath it has to be a vapor unless it is rolling out of your mouth as smoke. What is the vapor pressure of THC?
- bribroder 8y ago
  Here's an interesting tidbit: The tricky thing about THC, however, is that it is a large and complex molecule unlike ethanol, the main compound in alcohol, which is relatively small and simple. According to Tom Bruno, a NIST research chemist and co-author of the new paper, the vapor pressure of the THC compound is “very, very low,” which makes it difficult to measure. Bruno, along with fellow NIST researcher and lead author Tara Lovestead, found a way to skirt around this issue by measuring THC vapor pressure with a vapor-capturing technique called PLOT-cryo. It works by trapping vapors in a solid substance that coats the inside of a small tube. Because the tube is so small, Bruno said, the process is very efficient. “You don’t have to collect a lot to get an analyzable result,” he remarked. The PLOT-cryo device works like a very sensitive nose. It can sniff out different compounds from the air, and has been previously used to identify explosives as well as decaying flesh. https://www.seeker.com/health/new-thc-finding-paves-the-way-toward-an-effective-marijuana-breathalyzer https://www.seeker.com/health/new-thc-finding-paves-the-way-...
  - ohiovr 8y ago
    Thank you that was interesting.

28 points by newman8r 8y ago

Why use less reliable proxies like breathalizers to gauge impairment when we now have the technology to measure it far more directly: convert traffic cop cars into mobile virtual reality driving simulators. Put a gaming laptop in the trunk, and the DWI suspect behind the wheel with a VR headset on and let them drive through a couple of minutes of reasonably challenging simulated traffic. Let software come up with an objective score and store the simulated session as evidence if they fail. Not only does this more directly measure impairment, it catches any cause of it, not just a particular substance. Virtual driving impairment will correlate with real driving impairment far better than parts per million of a molecule in the bloodstream.

deleted 8y ago
[deleted]
RobLach 8y ago
Very difficult to prove that the simulation is an accurate and easy to grasp representation that holds up in a court.
- hirundo 8y ago
  You could put the judge and/or jury in VR headsets for the playback. They would see just what the defendant saw, in four dimensions. That's amazingly high fidelity, and the chain of evidence can be demonstrated with a checksum. Compared to judging the inner workings of a breathalyzer, that pretty good.
  - bdcravens 8y ago
    All that proves is they failed a simulation, not that they were under the influence. Burden of proof lies with the prosecution.
    - hirundo 8y ago
      Seems like we should care more about driving impaired than about driving under the influence. The former is what we're trying to prevent by policing the later. You can be impaired without being under the influence, and under the influence without being significantly impaired.
      - bdcravens 8y ago
        I don't disagree, but I've had moments when I was a terrible driver: I was tired, I was pissed off, I was stressed, I had just received bad news, I was quitting nicotine, etc.
        hirundo 8y ago
        I've done that too, and I should have been busted for that too. Is it really better to risk other lives due to lack of sleep than from too many drinks? For some stranger's little kid in another car's back seat, impaired is impaired.
        bdcravens 8y ago
        By that standard, that stranger could be arrested for careless driving because the child in their back seat was screaming for a juice box and they were allowing themselves to be distracted.
        hirundo 8y ago
        Failure to control a vehicle is a violation in the places I've lived. It applies regardless of circumstances. Ice patch, animal runs in front, screaming toddler, whatever the cause, you can still be arrested for it.
        bdcravens 8y ago
        In which case you need no VR setup, as the event happened prior to the officer interaction. Most of what you described is a ticket, not an arrestable offense.
corndoge 8y ago
"You suck at video games, enjoy your DUI" Honestly this sounds unreasonable.
pmichaud 8y ago
It's an interesting idea, but the critical issue with it is that it's not illegal to be bad at driving. That could change, but that's how it is now.
- nerfhammer 8y ago
  Ah, but it's illegal to drive without a license and the test is a de facto driving test so you could make it so that if you fail it you won't get arrested but you get your license suspended on the spot.
  - bdcravens 8y ago
    Currently simulations aren't valid driving tests, so that entire section of law would have to change. Moreover, does any state do on-demand driving tests? Typically you set the appointment, not the state. Additionally Texas (I'm sure other states are similar) doesn't even "suspend on the spot" for DWIs (you have 40 days or more from the incident before the suspension is effective).
- mavhc 8y ago
  It'll illegal to drive dangerously though, surely. It's a test that removes the license to drive from those who can't drive properly, whether due to old age, eyesight, drugs, tiredness. Only self driving cars for you.
  - bdcravens 8y ago
    The tests for obtaining a license allow for multiple attempts, and are administered by officers trained for that job, and aren't based on a video game installed in a cruiser. > It'll illegal to drive dangerously though, surely. Yes, and for all but the worst offenses (say, 30+ miles over the speed limit) the penalty is merely a fine and points against your license.
- mjfl 8y ago
  If someone drives as if they are drunk, all the time, then I don't think they should have a license as they are clearly a danger to public health. On a similar note, the driving test for a license could include a run in the simulator to both test driving skills and establish a baseline for the test. Then the impairment could be measured as relative to that baseline. I think it's a good idea.
bdcravens 8y ago
You're describing a fancy field sobriety test. There's a reason why those who fail field sobriety tests for alcohol are then asked for a breath sample (or when they refuse, a blood test) A criminal defense lawyer would tell their clients to say in court they intentionally failed the test. (Burden of proof still lies with the prosecution) You can't be convicted for failing a test. You can only be convicted of being under the influence.
- nasredin 8y ago
  I read something (a legit study IIRC) that breathalyzers are not that accurate and if you don't hold them right can increase the BAC. And NO you CAN be convicted for failing the test. The evidence is just a paper reciept from the breathalyzer. The reason you choose the blood test is so you have evidence for later. Also you will sober up a little while you wait.
  - bdcravens 8y ago
    To be clear, I mean no one is being convicted of failing a field sobriety test with no breathalyzer or blood BAC results.
- thebigspacefuck 8y ago
  I believe there was a case in Colorado where a medical Marijuana user had enough THC in their blood to be considered impaired but they were able to pass a field sobriety test so they weren't convicted of a DUI. The problem is that the amount of THC you need in your blood to impair you is different for every person so it's hard to develop a test for it. A driving simulator makes sense to me, though once you have a bunch of adrenaline kicking in and are totally focused on not going to jail, you may perform better than when you are relaxed in the comfort of your own car.
bequanna 8y ago
I have no idea legally how this would work, but is 'proving' impairment using your proposed method enough? I would think the missing piece would still be linking impairment to a substance or condition that the driver knew about, but drove anyway. ...which is why a simple sobriety test is typically given before a Breathalyzer.
- hirundo 8y ago
  We should care more about getting incapable drivers to stop driving than detecting insobriety. We should want safety police, not morality police. And strictly on the morality angle, I don't think driving drunk is more culpable than driving over tired or over angry. I find those things are about as easy to detect in myself as drunkenness.
jotm 8y ago
Aside from the other issues, how do you expect your average police officer to handle that thing? You know they're not exactly the brightest people, right?
- mindslight 8y ago
  You tell the cop there's a problem with the simulator. He sits down. You point out that other driver just ran a red light. He gives chase on the simulator. You walk away. Sorted.
codeulike 8y ago
producer of Black Mirror bookmarks this comment

scarface74 8y ago

It couldn’t be any worse than “specially trained officers” who are able to detect whether someone is high by thier mannerisms and arrest people who aren’t using anything. https://www.11alive.com/article/news/investigations/the-drug-whisperer-drivers-arrested-while-stone-cold-sober/85-437061710 https://www.11alive.com/article/news/investigations/the-drug...

eeeeeeeeeeeee 8y ago
Exactly. The article even says as much. It simply detects if someone smoked something with THC in the last two hours. So there is no consideration for actual impairment? My bullshit detector went off when the creator of the device said "this device has a lot of science in it."
- singingfish 8y ago
  Cannabis detection devices in Australia (NSW anyway, maybe VIC and other states) seem to have a detection window of a couple of days or more. So it's almost entirely moral policing operational over here. This would be an improvement on that.
- mchahn 8y ago
  My bullshit detector went off when the article said "the number of drivers involved in fatal crashes who tested positive for marijuana is up significantly" (a reference to Colorado). Duh, the overall percentage of the population smoking dope went up when legalized.
NikolaNovak 8y ago
That article is completely terrifying. * I am much too much of a control freak to ever ever try drugs; no moral issue, just not for me. * I have a drink of something on social occasion maybe once or twice a year, maybe not. Never got behind the wheel with even a sip of alcohol that day, let alone a glass, let alone anything approaching legal limit. But I'm a klutz and I'm an introvert and I get nervous easily and I have NO idea what kind of "signs" my body would display in stressful situation with a police officer at night (my body an my brain have an uneasy working relationship - we mostly put up with each other:). It is very literally my nightmare scenario to be accused by a police officer of intoxication where none exists. As much as I 100% support them, I'm probably more afraid of roadside checks than an actually inebriated person.

ohiovr 8y ago

I would like to know how this works. THC is an oil or resin. For it to appear in your breath it has to be a vapor unless it is rolling out of your mouth as smoke. What is the vapor pressure of THC?

bribroder 8y ago
Here's an interesting tidbit: The tricky thing about THC, however, is that it is a large and complex molecule unlike ethanol, the main compound in alcohol, which is relatively small and simple. According to Tom Bruno, a NIST research chemist and co-author of the new paper, the vapor pressure of the THC compound is “very, very low,” which makes it difficult to measure. Bruno, along with fellow NIST researcher and lead author Tara Lovestead, found a way to skirt around this issue by measuring THC vapor pressure with a vapor-capturing technique called PLOT-cryo. It works by trapping vapors in a solid substance that coats the inside of a small tube. Because the tube is so small, Bruno said, the process is very efficient. “You don’t have to collect a lot to get an analyzable result,” he remarked. The PLOT-cryo device works like a very sensitive nose. It can sniff out different compounds from the air, and has been previously used to identify explosives as well as decaying flesh. https://www.seeker.com/health/new-thc-finding-paves-the-way-toward-an-effective-marijuana-breathalyzer https://www.seeker.com/health/new-thc-finding-paves-the-way-...
- ohiovr 8y ago
  Thank you that was interesting.