Full-Body Airport Scanners Downsizing For Doctors/Dentists

An anonymous reader writes "Cheap handheld terahertz scanners that do the same thing as those big bulky full-body scanners at the airport could be in your doctor's and dentist's office soon. The Semiconductor Research Corp. has successfully sponsored chip maker Texas Instruments in making cheap CMOS chips that do the same thing as those refrigerator sized full-body scanners at the airport. The resulting handheld versions can be tuned to look inside your teeth in the dentist chair and under you skin at the doctor's office. The best part is that terahertz rays are completely safe, unlike the X-rays used today by dentists and doctors which can cause cancer. Count me in!"

Comments

"completely safe"

[Hanzie]

I'll wait to believe terahertz radiation is "completely safe" for a little while, yet.

Re:"completely safe"

[Isaac-1]

Safe means we don't know what bad thing it does yet.

Re:"completely safe"

[Anonymous Coward]

Completely. Safe.

Just like DDT.

Re:"completely safe"

[Anonymous Coward]

I'm with you on that.

However, there is evidence that a certain amount of radiation is actually needed to stay healthy, which is really the main defense behind a lot of the radiation you see with your doctor/dentist and probably even with these things to some degree.

Re:"completely safe"

[the eric conspiracy]

With the sort of logic that is popular these days we would have rejected fire as unsafe (radiation from a fire is higher frequency than this THz - i.e. very far infrared) and still be eating our food raw in unheated caves.

There is no such thing as "completely safe". The idea is preposterous. It is even more preposterous that we can prove something to be completely safe. Every heartbeat or breath you take is at great risk.

It's all about rational risk assessment and testing. Given the fundamentals here there is no reason to be concerned about the safety of terahertz radiation. It is certainly far safer than the alternatives which have large known risks.

Re:"completely safe"

[Anonymous Coward]

At least DDT is safer than malaria.

Re:"completely safe"

[viperidaenz]

It's pretty safe and has been tested over a very long time period. They've even given certain THz frequencies their own names.
440THz is sometimes called "red"
560THz is sometimes called "green"
640THz is sometimes called "blue"

Re:"completely safe"

[Darkness404]

The problem isn't that it involves risk, it is that things that are "completely safe" eventually get abused to the point that they are no longer safe. X-Rays can cause cancer, but we know that x-rays cause cancer and therefore doctors/dentists are more reluctant to use them. Back when X-rays were considered 100% safe, we used them to see how well shoes fit! And other novelties.

Is terahertz radiation safer than x-rays? Quite possibly. If we use terahertz radiation to excess will it be safer than x-rays? Quite possibly not.

Re:"completely safe"

[the eric conspiracy]

There was never a time when X-Rays were considered completely safe. Roentgen and Thompson both issued warnings regarding overexposure. Within a year of their discovery reports of injuries started appearing.

http://goatrevolution.com/blog2/2006/11/10/radiation-part-cinque-further-uses-and-discoveries-of-x-ray-radiation/

Re:"completely safe"

[MightyYar]

DDT is pretty safe if you aren't a bird.

Re:"completely safe"

[MightyYar]

I was with you up to green, but blue is a menace! It's a blue menace!

Re:"completely safe"

[Darinbob]

It means don't eliminate my chance to make a buttload of money until you have proof that I'm killing people. After all money is more important than any other consideration.

Re:"completely safe"

[Anonymous Coward]

Until we realize that terahertz rays are a signal to summon destructive fifth dimensional beings from a nether boson vortex, it will be "completely safe".

Re:"completely safe"

[Anonymous Coward]

No doctor or dentist I've ever been to was ever 'reluctant' to call for an x-ray. As long as you're insured, it's free money for them to call for an x-ray, whether you need it or not. Last time I went in for neck pain, the doctor actually told me that whatever was causing my pain would most likely only show up on an MRI (as it was most likely due to tissue, not bone, issues), but he wanted to take an x-ray "just to see", and that he'd call for an MRI only if I still had pain a week or two later.

As long as every doctor/dentist has an x-ray machine in-house that they can charge your insurance company for, whether it's really needed or not, they'll use it. If we can replace x-ray with some other most likely less-harmful tech, I'm in.

Re:"completely safe"

[dyingtolive]

This could not get upmodded enough if we stood atop buildings with megaphones screaming it.

Re:"completely safe"

[__aaltlg1547]

Look, you want to cook your cojones with terahertz scanners, go right ahead. But don't try to persuade me that it's "completely safe" or even safer than competing technologies like MRI and ultrasound without a large body of evidence.

Re:"completely safe"

[__aaltlg1547]

DDT is pretty safe if you aren't a bird.

It's safe sex for birds of prey.

Re:"completely safe"

[Anonymous Coward]

Yes! They said that X-Rays and radiation were safe also. In the early years of the 1900's they sold radium elixirs that were supposed to be good for you. Up to the 1950's they had X-Ray machines that were used to check the fit of your (and your children's) shoes. They only banned X-Ray machines from shoe stores when many shoe salesmen came down with radiation related health problems. Do we really know that terahertz radiation is "completely safe"? Not at the moment. The manufacturer of these devices is probably promoting them as "completely safe". That is not unbiased research into those claims. We need more data and also from an unbiased source and also more time into the long term effects.

Re:"completely safe"

[Samantha Wright]

FWIW, the available research is pretty clear that terahertz radiation poses little or no threat to the body under biological conditions. There's lingering concern that it may have a small ability to affect lipid bilayer permeability (which could imbalance how cells pass messages, receive nutrients, and eliminate waste), but over all, a THz exposure is a lot like being bombarded with visible or infrared light: it will warm you up if left on for too long, but it's not really dangerous on its own. The radiation is too high-frequency to excite any of the electrons orbiting the atoms in the human body (which is how UV causes damage), and much, much too low-energy to knock an electron onto a different atom (which is how X-rays and gamma radiation cause damage.) Any effects it does have must be extremely subtle—and the body is very good at handling subtle problems, since we replace almost every cell every ten years on average.

Re:"completely safe"

[Nkwe]

It's pretty safe and has been tested over a very long time period. They've even given certain THz frequencies their own names.
440THz is sometimes called "red"
560THz is sometimes called "green"
640THz is sometimes called "blue"

And they stopped there because 640 THz should be enough for everybody.

Re:"completely safe"

[Anonymous Coward]

The 'alternatives', in the case of the TSA, should be regular old fashioned magnetometers. Period. No false choices between this and x-rays, when the rational, most effective, and of course cheaper alternative is to use neither.

Re:"completely safe"

[Phroggy]

When the dentist takes x-rays, they first cover me with a lead blanket from neck to knee and then they leave the room while the pictures are being taken. That's because we know that x-rays are dangerous, and we understand how they're dangerous and what steps should be taken to minimize the risk while still taking advantage of the technology.

If it's "perfectly safe", no such precautions will be taken. Decades from now, we'll know whether they should have been.

Re:"completely safe"

[davester666]

Dude, don't scan my junk!

Re:"completely safe"

[Anonymous Coward]

Edison seemed to think it was perfectly safe and into the '50s stores were using the fluoroscope to make sure that shoes were properly fitting.

You can always find somebody that thinks something is dangerous from the start, the questions really are whether they are credible and how seriously they're being taken.

Re:"completely safe"

[Svartormr]

I was with you up to red, but before you get to green there's 540THz, sometimes called "yellow", but yellow is a threat! It's a YELLOW peril!

Re:"completely safe"

[Warma]

You are not taking into account, that doctors are wary of using MRI devices for scheduling and expense reasons. An X-ray image from a leased dental device is almost free (less than a hundred euros for private institutions here) and takes mere minutes, while an MRI scan costs thousands of euros and may take hours.

Also, since MRI is more useful in a wider variety of situations, someone else probably needs it more or needs it sooner - you might end up having a huge waiting time to get yourself scanned. It is prudent to take the x-ray, because if the doctor can see the ailment there, the MRI scan may not be needed at all. He will also send you out, because if the pain disappears in a couple of weeks, the MRI won't be necessary. Money, time, work, and possibly lives, might be spared.

If you are worried about the risks of a single x-ray, I assure you that they are beyond neglible - especially if you compare that risk with the possible wasted utility of an MRI device.

Re:"completely safe"

[Trogre]

Well, until the recommended system requirements for Windows 8 are published anyway.

Re:"completely safe"

[Anonymous Coward]

that terahertz radiation poses little or no threat to the body under biological conditions

Really. Which "biological conditions" are you speaking of?

Re:"completely safe"

[Samantha Wright]

I mean "subtle" as in "not causing cancer."

Re:"completely safe"

[Samantha Wright]

The DNA in certain immune cells can be damaged by terahertz radiation if they're removed from the blood first.

Re:"completely safe"

[Anonymous Coward]

Back when X-rays were considered 100% safe, we used them to see how well shoes fit! And other novelties.

Yup, my mom (just turned 80) mentioned that to me a while back, they're going on a 2 week vacation to Japan this year, and I mentioned 2yrs ago would have been better (a.k.a. pre-Fukushima :-P), and she said she had her feet x-rayed for shoe fittings a lot when she was a kid, and her feet still work. Besides, as she said, at 80 (81 for dad) they're "only expecting another 10 years tops - what's it really going to hurt"?

Re:"completely safe"

[Xest]

The problem I have with TFA is use of the term completely safe. Some studies have shown there is risk (something like 1 in 2million) but they have weighted this in the context of the relative increase in cancer incidents being negligible compared to the existing chance of getting cancer.

This is a fair and valid argument, but where I believe it falls down is that the risk of getting cancer from T-Ray scanners is then non-negligible compared to the chance of dying or being injured by a terrorist attack prior to their introduction.

So sure, the chance of any harm from them is so absolutely tiny so as not to be worried about it, but the chance of harm from a terrorist attack is even smaller. So the question remains, why bother with the expense of them? Why bother with the increased risk at all, no matter how small? Why bother when they don't even necessarily work as there are still a number of ways to slip things past them?

Fundamentally it's because terrorist incidents cause a number of deaths in a small timeframe in a single place so trigger the nonsensical shock reaction people are prone to, whereas deaths from this sort of thing are spread far and wide over a longer period.

Still, this is just regarding airport scanners, as a tool for doctors and dentists they should do far more to save people's lives than risk them, by a few orders of magnitude no doubt so would be well worthwhile in this context.

Re:"completely safe"

[Anonymous Coward]

Terahertz waves are NOT completely safe - not even close. The radiation can excite resonances in many biological molecular structures, some with highly damaging consequences. Sunburn is caused by higher frequencies. Damage occurs at specifice frequencies all the way down thru the microwave spectrum.
Standing waves inside biological tissue can multiply the power density of the radiation by orders of magnitude in very small localized regions, causing tissue and nerve damage.

Re:"completely safe"

[Guppy]

DDT is pretty safe if you aren't a bird.

Depends how you define "safe". DDT won't kill you, but it is a persistent and bio-accumulating endocrine disrupter -- even decades after being banned in most places, it is still universally detectable in human breast milk (one of the tissues in which it concentrates).

Re:"completely safe"

[Anonymous Coward]

Well, golly gosh! Near ultraviolet is 768-999 THz. I guess if you can express it in THz is must be completely fucking safe!

For those who don't know, terahertz imaging uses frequencies on the far side of infrared, almost into microwave. We're talking around 0.3-3 THz.

Re:"completely safe"

[gr8_phk]

And 0.000101.1THz is WRIF in Detroit. Making jokes about visible light is misleading. What do we call 1-50THz?

Re:"completely safe"

[lightknight]

Lol, super-tumors.

Re:"completely safe"

[lightknight]

The Kraken.

Re:"completely safe"

[lightknight]

Which, putting aside its usage as a political football by environmentalists, is kind of responsible for the lack of swarms of mosquitoes that have plagued this continent and a few others before its introduction. Historical journals document how good we have it now compared to the early pioneers.

Re:"completely safe"

[lightknight]

"Well, they're all going to die someday anyways."

Re:"completely safe"

[the eric conspiracy]

Are you saying Roentgen isn't credible? In most places those things are still called Roentgen rays.

The guy was only the first Noble laureate in Physics.

Man that has to be one of the biggest FRSTS.

Re:"completely safe"

[mr1911]

Given the fundamentals here there is no reason to be concerned about the safety of terahertz radiation. It is certainly far safer than the alternatives which have large known risks.

Not quite. Terahertz radiation is by no means "certainly far safer" than choosing not to be irradiated by any method.

Re:"completely safe"

[Anonymous Coward]

How is this not just a physics and chemistry problem? We know the frequency of the wave and energy output. We know the targets molecular make up, and reactions to other frequencies. Why are we not simulating this type of model to understand the long term effects of this type of radiation, before even implementing the technology? We have all this computational power, yet we're not actively using it for policies that are being directly implemented into our lives.

This type of scenario leads me to think that, if a global life-changing scientific breakthrough ever occurs, it will be squashed out of fear that it will disrupt the global markets.

Re:"completely safe"

[dav1dc]

I'm sure that many decades ago when X-Rays were first introduced, they were also touted as being "completely safe" at the time as well... until we learned better. :(
Seems to me that human beings rush to realize the profit potential from their ideas, long before they fully evaluate any potential pitfalls that could arise from them...

But considering that tobacco industry has been selling a product that kills their customers for years and they're still in business, perhaps I have over-valued the importance of selling products that don't kill their consumers?!?! But in the mean time I'd personally rather not be a guinea pig for terahertz beams.

Re:"completely safe"

[judoguy]

While in horrible not-yet-fully-socialized-medicine America, you can get an MRI quite cheaply, sometimes located in shopping centers. http://www.mricenters.com/

Re:"completely safe"

[Anonymous Coward]

Nikola Tesla also said they were unsafe. This is a guy who spent half his life designing deathrays, he knows unsafe when he sees it.

Re:"completely safe"

[Anonymous Coward]

Terahertz is down near the infrared, complete opposite end of the spectrum from UV, so it can't cause sunburn. It is also much higher than radio frequencies, so it can't excite biological structures without, eg, removing the DNA from a cell.

In a normal human, the worst it can do is denature proteins through heating. But to do that, they'd have to literally cook you and you'd notice when your skin started charring before it did any invisible damage.

Re:"completely safe"

[Anonymous Coward]

The summary says that genotoxic effects occurred after exposures exceeding one hour. I'd be interested in knowing if there was any replication.

Re:"completely safe"

[SomePoorSchmuck]

You are not taking into account, that doctors are wary of using MRI devices for scheduling and expense reasons. An X-ray image from a leased dental device is almost free (less than a hundred euros for private institutions here) and takes mere minutes, while an MRI scan costs thousands of euros and may take hours.

Also, since MRI is more useful in a wider variety of situations, someone else probably needs it more or needs it sooner - you might end up having a huge waiting time to get yourself scanned. It is prudent to take the x-ray, because if the doctor can see the ailment there, the MRI scan may not be needed at all. He will also send you out, because if the pain disappears in a couple of weeks, the MRI won't be necessary. Money, time, work, and possibly lives, might be spared.

If you are worried about the risks of a single x-ray, I assure you that they are beyond neglible - especially if you compare that risk with the possible wasted utility of an MRI device.

Congratulations on your European bankruptcy-headed social democracy. At least everyone drives off the cliff together. That's true solidarity, comrade!

And while at the current moment I am able to obtain an MRI (and most other diagnostic imaging) in the United States of America in less than 48 hours (and often same-day) of visiting my doctor, you can take heart in the fact that those who would like to move us into your continent's bureaucratically-rationed system of health control have won a major victory with the trojan horse legislation known as the Affordable Care Act, which was very carefully designed to destroy the private insurance system and leave a vacuum which will be filled by the virus known as "single-payer" medical care.

Re:"completely safe"

[Anonymous Coward]

Well, repeated exposure is dangerous. If they didn't take precautions, the dentist would be exposed to X-rays from all their clients.

Re:"completely safe"

[Ungrounded Lightning]

Unfortunately, that misses a point:

The individual photons of terahertz radiation are at far too low an energy to ionize an atom or molecule or otherwise substantially affect a molecular bond, most foldings, and other molecular behavior. (That's a vast improvement on x-rays, where each photon has enough energy to ionize anything it interacts with, demolishing molecular bonds and spraying reactive species throughout highly-organized structures.)

But terahertz radiation is is COHERENT. That means billions of photons gang up, with their electric and magnetic fields aligned. Then these gangs march by in-step for timescales that are enormous at molecular scales. So biological molecules and structures may still be strongly affected.

Conductive structures whose (electrical) length is related to a half-wavelength of the frequency in use, along with structures that vibrate at that frequency and have unbalanced charges, can absorb energy from multiple cycles of the signal, "pumping up" the resonance until enough energy is accumulated to cause damage.

Even without such resonance, the field of a single half-cycle may be strong enough to affect a molecule as strongly as a single photon of a considerably higher energy.

So using lower energy photons may turn out to be harmless, and almost certainly will be less harmful than using ionizing radiation. But some biological structures may turn out to be vulnerable to it. It needs to be tested. Further, EACH FREQUENCY to be used needs to be tested. With resonance phenomena and fixed molecular sizes you can't generalize from one frequency to another.

On the other hand, if tuned molecular effects ARE significant there is an opportunity to discover them and use them to create new beneficial interventions. B-)

Re:"completely safe"

[Anonymous Coward]

That paragon of accuracy, Wikipedia, agrees that we don't know what bad thing it does yet -- http://en.wikipedia.org/wiki/Terahertz_radiation#Safety

Re:"completely safe"

[Hatta]

If you are worried about the risks of a single x-ray, I assure you that they are beyond neglible - especially if you compare that risk with the possible wasted utility of an MRI device.

The risk of a single x-ray, multiplied by millions of people is not negligible. And the wasted utility of an MRI device wouldn't be a problem if we built more MRIs to offset the X-rays we should be deprecating.

Re:"completely safe"

[Samantha Wright]

There was an article here a week or so ago that answers your question. The TSA is a psychological warfare campaign being carried out under the guise of a security practice. Its purpose is to scare would-be bombers into staying home. When there's a credible threat, they introduce new policies until the problem goes away. That's why grandpa is allowed to keep his jacket on—because he isn't likely to be impressionable or political enough to carry a bomb.

In essence, it's more straight out of George Orwell than people realize, but slightly less anti-citizen than most stereotypically Orwellian practices.

Re:"completely safe"

[Samantha Wright]

The summary I posted came from this site, which includes a rather lengthy database of biological and abiotic THz spectra. I am believe what you are saying is medically irrelevant.

Re:"completely safe"

[noahwh]

An X-ray image from a leased dental device is almost free (less than a hundred euros for private institutions here).

If you had to pay 100 Euros for a hamburger would you consider it "almost free"?

Re:"completely safe"

[Anonymous Coward]

With the sort of logic that is popular these days we would have rejected fire as unsafe

The hackles being raised at "completely safe" is b/c it's in the summary. The summaries have become op-ed pieces and not summaries anymore. Further your comparison with fire is apples and oranges. Fire exists in nature (no, I know not everything in nature is safe but it is *natural*) and these scanners come from a lab. You can't compare something I can find walking through a forest and something created in a lab using science and machines. I have to call strawman here.

Hackles are also being raised b/c these things were shipped to market so fast for the TSA that there hasn't been sufficient time to see if there are side effects.

Re:"completely safe"

[stephanruby]

Only the sarcastic attention-grabbing summary says it's "completely safe".

The actual article seems to imply the opposite. The actual article claims that Terahertz-rays are safer than X-rays. And the article does not advocate using T-rays where radios have never been used before. It's only advocating replacing existing X-ray machines with T-ray machines, especially in dental practices and some medical practices, where a T-ray can do as a good a job as an X-ray (at least, according to one of their researchers).

Disclaimer: T-ray is my own abbreviation. It's probably not the correct one.

Re:"completely safe"

[hazydave]

Well, there's physics and there's physics.

We KNOW that these lower-range Terahertz-band radio waves do not have enough energy to break chemical bonds or ionize atoms or molecules, which is the big problem with ionizing radiation such as high frequency UV and X-Rays. But there is some evidence that they may cause damage to DNA via non-linear resonance.

Thing about "completely safe"... it changes as you discover new ways to cause damage.

Re:"completely safe"

[hazydave]

Depends on where you live, I guess. Here in the good old US-of-A, my wife has been in for multiple MRIs and CT scans, treatment for cancer discovered two years ago. In our local (South Jersey) MRI facility, it's at least a week to get an appointment, most of the time. And they do the same thing... X-Ray, then MRI if they think it's needed. And most X-Rays are done at radiation specialty centers -- doctors rarely have X-Ray gear. Dentists, sure, because they're ok with very specific and simple gear. But the current state of the art makes the old family doctor's X-Ray machine a dinosaur.

Re:"completely safe"

[hazydave]

I'm sure there are MRI device companies more than happy to take your order.

Machines run between $1-$3million, plus maybe another $500K for the installation site. And they can cost $500K-$1M to run each year.... gotta keep that liquid nitrogen going for the superconducting magnets. The useful life of the typical machine these days is about seven years, though many healthcare companies are using them about twice as long. You know when you're getting treated at such a facility -- the machine's down on a regular basis.

Re:"completely safe"

[viperidaenz]

Infrared. Far infra red is around 1THz, Near infra red is around 300THz.
Most humans experience this as radiant heat

Re:"completely safe"

[izomiac]

A single X-ray exposes you to 1 to 20 microsieverts. For comparison, this is the extra radiation exposure equivalent to living in a concrete building for a week to three months. The average person is exposed to 10 uSv per day.

Any ionizing radiation exposure causes mutations in DNA. Specifically, it ionizes it and causes strange structures to form, like thymine-thymine dimers. Fortunately, we have DNA repair mechanisms that fix such problems. One such mechanism is homology directed repair, which uses the homologous strand of DNA to accurately repair defects in the other strand. (This is the system disabled by the BRCA mutation.) These repair mechanisms obviously have a limit to how quickly they can repair DNA, but that limit can easily handle mundane sources of radiation.

In other words, unless someone gets a ludicrous number of X-rays (e.g. occupational exposure), then modern machines should be harmless (if properly configured). You can think of DNA as RAID1 with additional parity. Unless there's a significant exposure (i.e. 100,000 uSv per year is the lowest level linked to cancer) then your DNA can recover perfectly. So, giving millions of people a single x-ray is not equivalent to giving a single person millions of x-rays, and likely wouldn't cause a single extra case of cancer.

Re:"completely safe"

[Fned]

the questions really are whether they are credible and how seriously they're being taken.

Are you saying Roentgen isn't credible?

Gee, I wonder if that's what he was saying. Gosh, mayhap I'll have to go back and read GP again and see for myself.

Re:"completely safe"

[Samantha Wright]

Well, here's where the report's from. If you'd like to poke through it, you might very well glean some useful information. It looks very much like they did in fact test all medically-relevant frequencies across a wide range of samples. Feel safe yet?

Re:"completely safe"

[Samantha Wright]

The answer lies in here somewhere. I think it might be this one in particular.

Re:"completely safe"

[Hatta]

Every major radiation safety authority in the world uses the linear no-threshold model for estimating risks from low dose radiation. Whatever evidence there is for DNA repair hasn't been enough to convince them, so I'll stick with that model for my predictions as well. Currently, the evidence is very limited, and only applicable to cell culture. Claims like "your DNA can recover perfectly" are grandiose overstatements at this point.

Re:"completely safe"

[Anonymous Coward]

No doctor or dentist I've ever been to was ever 'reluctant' to call for an x-ray. As long as you're insured, it's free money for them to call for an x-ray, whether you need it or not. Last time I went in for neck pain, the doctor actually told me that whatever was causing my pain would most likely only show up on an MRI (as it was most likely due to tissue, not bone, issues), but he wanted to take an x-ray "just to see", and that he'd call for an MRI only if I still had pain a week or two later.

As long as every doctor/dentist has an x-ray machine in-house that they can charge your insurance company for, whether it's really needed or not, they'll use it. If we can replace x-ray with some other most likely less-harmful tech, I'm in.

To be fair to your doctor, just because he THINKS it's an issue with soft tissue, doesn't mean he can simply assume it's so. Medicine is not a shoot from the hip practice, it's methodical. Tests are ordered on the basis of ruling OUT a diagnosis just as often, if not more so, then to confirm one. So while he thought was soft tissue (confirmed on MRI, a very expensive test), he still had to rule out bone problems (easily visible on x-ray, a relatively cheap test).

So while you see it as him ordering a test just to make the money, I see him practicing good medicine designed to be thorough.

Re:"completely safe"

[Anonymous Coward]

You haven't been to see me, then. I am a Family Medicine physician. While I do order tests including "x-rays" on some patients, I find that the most important part of a patient's workup is their history. Their own story of their symptoms, the evolution of their problem, their family history and their personal background is by far the most important information I can get to begin helping my patient. I see around 125 patients each week, and order maybe 6 x-ray studies. The only time I really feel obligated to order an x-ray is when a patient has a painful, swollen part of their body after sustaining significant trauma. The rest of the time I first speak with the patient and perform a focused physical examination.

Re:"completely safe"

[Phroggy]

Well, repeated exposure is dangerous. If they didn't take precautions, the dentist would be exposed to X-rays from all their clients.

Of course - we know this about x-rays. But these new terahertz imaging things are "completely safe", which means there's no reason to take such precautions with them, right?

Re:"completely safe"

[Xest]

Will it ever work though? Can you really scare a fanatic who is willing to die for his or her cause?

The only people who seem to get screwed are those who are innocent. It's not a very good metric, as the sample size is so small, but since 9/11 every attempt at getting a bomb on the plane has actually succeded at bypassing security - the shoe bomber, and underwear bomber, the bombs on DHL planes from Africa. We were saved from their attempts only by the fact that their bombs failed to detonate in both cases.

If it's a psychological warfare campaign, it seems as fundamentally flawed as it would be as the security campaign it's sold as.

All the others that have been prevented have been prevented before they even got to airport security by good old fashioned intelligence work.

Re:"completely safe"

[Samantha Wright]

Read the review I linked—they don't bother stopping shoe-bombers. The CIA monitors a threat, and the TSA ramps up their response until the threat cracks and leaves the country. The TSA isn't really a generalized anti-terrorism machine, only an anti-Al-Qaeda machine. Security theatre scares the real bad guys, real safety doesn't—and it's (infinitely) easier than actually focusing on bombs. By the time the dozen reports on the countermeasure-of-the-month's ineffectiveness has come out, it's long after the fact, and the baddies have already been scared enough to cancel their plot.

And yeah, without a doubt it's the most terrible abuse of a security system ever devised. Clever, because there's no way people would put up with what it would actually take to make a flight risk-free (something about locking passengers in individual cabins during the flight comes to mind), but definitely squarely under the "you're horrible people" category.

Re:"completely safe"

[Anonymous Coward]

No, I think AC is saying that he was not being taken seriously by the people who claimed x-rays were safe.

          Although after reading the article you posted, I don't think the problem was that he wasn't taken seriously, but that safe levels of exposure we grossly over estimated. When fluoroscopes were used in stores, most scientists and governmentsts thought that serious injury could only be caused by repeated, prolonged exposure.

Re:"completely safe"

[Douglas Goodall]

As I have been saying for years, "Do anything to a thousand people and one will die." The world is just plain contrary.

Re:"completely safe"

[izomiac]

DNA repair mechanisms are well known, and taught in any introductory-level genetics course. The BRCA system is very well studied due to its clinical significance. The lowest yearly dose of radiation that has been shown to have an effect is 100 mSv, which is four orders of magnitude higher than we're talking about.

Radiation safety authorities have a long reputation of overreacting to low level radiation sources. For example, items that went into a radioactive area, and have measurable lingering radiation, were once (and perhaps still are) classified as radioactive waste. Even if such items were just as or even less radioactive than they were before being exposed. I can't entirely blame them, the radiation poisoning after WWII in Japan was an unexpected tragedy that we hope to prevent in the future, but we know a lot more about radiation now.

That said, linear no-threshold models would predict that everyone should show symptoms of radiation poisoning around 80 years of age, and people in high altitudes long before that. It's not a defensible hypothesis, having no supporting experimental evidence or physiologic rationale. Safety estimates are very conservative, so that's why they assume zero DNA repair, but that's not being realistic. The linear models are a simplification that breakdown at the extremes.

Of course, setting the exact lower threshold is quite difficult, since the population varies tremendously, plus it's somewhat trivial to differentiate between zero and essentially zero. The only time it becomes relevant is when you multiply very small, incorrect numbers (i.e. probability of causing cancer at trivial radiation doses) by very big numbers (i.e. millions of people) and get a number greater than zero.

You can visualize it like blood loss. If a person loses 2 liters of blood, they'll show certain symptoms. If they lose 3, the symptoms are a lot worse, and they'll probably die if they lose 5 or 6. You could likely construct a no threshold linear relationship out of this. But, obviously it breaks down when you say that you'd expect one person to die from blood loss for every 5,000 paper cuts.

Cheap and available ?

[Anonymous Coward]

I want something like this for home use.

Re:Cheap and available ?

[Sulphur]

I want something like this for home use.

Cheap, effective, safe : Pick two.

Abolish the TSA

[TheGoodNamesWereGone]

Scanners belong in doctors' offices, not airports.

Re:Abolish the TSA

[formfeed]

Scanners belong in doctors' offices, not airports.

This will surely help OB-GYNs to practice their love with women all across this country

Re:Abolish the TSA

[MightyYar]

Throw that on a poster and it'll be almost as worthless as those other platitudes: "Don't work harder, work smarter!"

Re:Abolish the TSA

[rbrausse]

Scanners belong in doctors' offices, not airports.

like Dr. Emma Garrison-Alexander?

[as a side note: in Germany, a Dr. in front of the name is an important status symbol, it is really unlikely to see a governing body of any bigger company/state agency/whatever with only one doctorate. Interesting, I saw your doctor comment and automagically expected lot's of Dr.'s, my German POV was wrong...]

Re:Abolish the TSA

[lightknight]

"There's no 'I' in team."

Re:Abolish the TSA

[ignavus]

Scanners belong in doctors' offices, not airports.

See, the TSA would be much more popular if they just advertised it as a free diagnostic scan and gave a certificate of health - or a diagnosis afterwards.

"Sir, you're carrying a bomb and a duodenal ulcer. Please step over here so we can disarm the bomb and give you emergency radiotherapy for the cancer."

Scanner for doctor?

[Anonymous Coward]

Couldn't the doctor just ask you to remove your clothes?

Re:Scanner for doctor?

[Anonymous Coward]

He can't ask for removing the skin. (Well, he can ask, but the only result will be that the patient goes to a different doctor.)

Re:Scanner for doctor?

[lightknight]

(Well, he can ask, but the only result will be that the patient goes to a different doctor.) -> Not if he is quick enough.

X-rays

[SwampChicken]

Didn't these used to say that X-rays were safe? Anyway, in IMHO the best option is to not to scan at all. Just let everyone board the plane and be on their way -or- we'll start scanning people boarding buses next.

Re:X-rays

[YukariHirai]

Just let everyone board the plane and be on their way -or- we'll start scanning people boarding buses next.

Yeah, the former option is never going to happen. No authorities ever give up powers like that without a very good fight, and usually expand them bit by bit.

Re:X-rays

[Anonymous Coward]

Didn't these used to say that X-rays were safe?

...X-rays, lead, asbestos, tobacco, mercury. If you go back far enough the list contains everything we know today to be unsafe. ...but I'm sure we know everything by now.

Re:X-rays

[bigtrike]

We've known that lead is poisonous for about 2,000 years.

Re:X-rays

[fido_dogstoyevsky]

Didn't these used to say that X-rays were safe? Anyway, in IMHO the best option is to not to scan at all. Just let everyone board the plane and be on their way -or- we'll start scanning people boarding buses next.

...with one of these "Cheap handheld terahertz scanners that do the same thing as those big bulky full-body scanners at the airport" thingies here.

Re:X-rays

[flyingfsck]

Most of those things only cause cancer in California.

Re:X-rays

[Anonymous Coward]

Yet it was used in paint, canned goods, and as lining for food storage, much more recently.

hell yeah!

[sribe]

If I were a dentist, I'd certainly want to know if you're packing heat before I start subjecting you to excruciating pain ;-)

Re:hell yeah!

[Anonymous Coward]

If your dentist is subjecting you to excruciating pain, I suggest you find a different dentist. Most dental procedures are completely pain-free these days. Some have residual soreness once the shot wears off; that's what they make Vicoden for.

Re:hell yeah!

[Anonymous Coward]

Some people may refuse those drugs for any number of reasons and so they have to endure the pain.

Completely Safe...

[Nethemas the Great]

As certified by the $10/hr TSA agent with barely a high school education.

Re:Completely Safe...

[Anonymous Coward]

As certified by the people who know the difference between ionizing radiation and radio waves, more like.

The only danger you face going through the terahertz scanner at the airport is the potential incompetence and arrogance of the officer of the law who is empowered to interpret the results.

Re:Completely Safe...

[artor3]

Do you really think that the TSA wage-slaves are designing multi-million dollar scanners in between confiscating toothpaste and groping tourists? You do know that they have actual scientists and engineers and doctors inventing this stuff... right? I'll trust their judgement over that of a random poster in an internet forum.

Re:Completely Safe...

[Intropy]

Come on. You can do that with anything.

Drinking tap water is safe. So you wouldn't mind if I submerged you in a tub of it for an hour?
Playing tennis is safe. So you wouldn't mind if I made you play in a hurricane?
Reading slashdot is safe. So you wouldn't mind if I made you sit there reading it for a week while force feeding you cheetos?

Re:Completely Safe...

[CelticWhisper]

Major correction: TSA screeners, despite having fake tin badges and cop-a-like uniforms, are NOT law-enforcement officers and have absolutely zero authority to do anything other than say "Sorry, you can't enter the airport terminal today, try again tomorrow." That's it. They cannot make arrests, they cannot detain you, they are forbidden from carrying firearms on the job and some have actually been arrested themselves for using their TSA uniforms and toy badges to impersonate real law officers.

I don't fault you for thinking they're LEOs - they've gone to great lengths to dupe people into believing that (reference the STRIP Act that would undo this) and are meeting with a disturbing level of success - but I do try to counter these misconceptions when I see them.

Re:Completely Safe...

[TooMuchToDo]

Reading slashdot is safe. So you wouldn't mind if I made you sit there reading it for a week while force feeding you cheetos?

Go on....

Re:Completely Safe...

[Svartormr]

Reading slashdot is safe. So you wouldn't mind if I made you sit there reading it for a week while force feeding you cheetos?

For many readers, this is their normal state of existence. >:)

Re:Completely Safe...

[ThatsMyNick]

True, but only technically. There are always real cops around TSA agents. All the TSA agent has to do is point at you (well, with some reason of course), and the cops would arrest you. Assaulting a TSA agent would not be considered assaulting a police office, and similar charges dont apply when dealing with TSA. Everything else though, is the same.

Re:Completely Safe...

[Anonymous Coward]

Ionizing radiation isn't the only potential hazard that exists in the electromagnetic spectrum. Heating that penetrates deep into the body could have unknown effects on protein structure and could catalyze reactions within the body. (There's a reason microwave catalysts are used in industrial chemistry.) While chances are really good that terahertz scanners are harmless to tissues, there's a non-zero chance that they aren't.

Plus, I think the issue the poster above was referencing was the recent news item in which a TSA agent ignored doctors' orders to force a teenager with an insulin pump through a THz scanner. Which broke the $10K pump. (Fortunately, it just stopped working completely rather than administer multiple, aka lethal, doses.) Now this was completely predictable to anyone who knows anything about how radio waves interact with electronics -- particularly sub-millimeter waves with metal wires and pins less than a millimeter apart.

But hey, it's not ionizing radiation, so it must be safe for everyone, right? I'm glad we have you (and the TSA) to speak so confidently for that rule of thumb.

Re:Completely Safe...

[lightknight]

A random poster in an internet forum frequented by scientists and engineers.

But I have a better idea. Let's grab one of the more expendable ones from the TSA, and stick 'em inside the scanner, fully powered up and constantly scanning, for a month. Unless we somehow manage to pick someone with the golden immune system of the gods, we'll know, at the end of the month, whether there is anything dangerous about these scanners. Well, immediately dangerous. If that person shows multiple metastasized tumors throughout their body, or proves to be sterile, when presumably they were healthy prior to the experiment, then we might want to run it again, a few times, on, I don't know, the congressmen who signed off on the purchase orders for these machines? Just to be sure. Somewhere around the 112th member of Congress who dies of systemic organ failure we can probably come to a consensus or something that they're probably unsafe. Maybe. I favor the selection criteria being 'the loud ones,' should we run out of cosigners on that gift to the industry of the inane.

Or we could do a blind study, and quietly install parts from one of the scanners inside the walls of the Senate or House. Well, the parts from a few of the scanners (the House / Senate is kind of big). Just so we can rule out stress, or something, from the study. Or perhaps we should install it in their offices. Finally going to make Political Science into a hard science.

Re:Completely Safe...

[PoopMonkey]

Easy way to rule out picking someone with the golden immune system of the gods... All employees of the TSA have to go in for a month. And any politicians who voted for approving anything TSA related.

Re:Completely Safe...

[Anonymous Coward]

LOL!

You know WHY we have these scanners at all?

ONE BIG MASSIVE FAT cheque to RAPISCAN. Thanks, Chertoff!

Yeah, I'm sure safety is what they're focussing on during development.

Remember how the scanners didnt have the capability to store images? Remember how that turned out?

BUT SURE! Go ahead and trust them now.. I'm sure this time, they;re not lying

Re:Completely Safe...

[Nethemas the Great]

Of course you could. However it wouldn't be as relevant. The author is asserting that non-ionizing radiation is "safe". I suggest that that wasn't necessarily true with an "in your face" obvious example. Just because it is "non-ionizing" does not mean that it is safe. Microwaves resonate with water molecules, sound waves resonate with physical objects, there is evidence that terahertz radiation can resonate with DNA. Resonance may achieved in all manner of physical systems. It simply requires a certain radiating frequency. These physical systems "can" break down if the resonance produced is strong enough. That is where the danger is. That is the big unknown that demands further research with regards to these scanners.

Re:Completely Safe...

[Nethemas the Great]

Which groups of scientists and engineers do you mean? The ones similar to those that design weapons, or promote fluoridation of the water supply, created shoe fitting fluoroscope, or the ones that just outright peddle snake oil such as radium water jars?

X-rays were safe too.

[Anonymous Coward]

I"m old enough to remember when X Rays were completely safe. They were installing them in shoe stores to check to see if your feet fit right in the shoes.

Re:X-rays were safe too.

[Internal Modem]

US patent D149088, Jean Otis Reineeke, "Design for x-ray shoe fitting cabinet", issued 1948-03-23
US patent 1614988, Lowe, J.J., "Method and Means for Visually Determining the Fit of Footwear.", issued 1927-10-05

Re:X-rays were safe too.

[Anonymous Coward]

I"m old enough to remember when X Rays were completely safe.

115 years is very old.

By 1897 the rays' dangerous side began to be reported: examples included loss of hair and skin burns of varying severity.

Bah! I preffer the good old days!

[hedgemage]

I don't want these fancy new scanners in my dentist's office! What's wrong with having the hygenist run me through the metal detector prior to performing an enhanced patdown?

Re:2 million years of evolution

[cheater512]

Yeah we need far more testing on radiation. Especially in the 400nm to 700nm range.

Sure they say its perfectly safe but how long have we been exposing ourselves to it? More data is required!

Re:Bah! I preffer the good old days!

[antifoidulus]

Guess it depends on how cute your hygienist is.

Re:2 million years of evolution

[cruff]

You are probably familiar with the usual laser safety warning:
Do not look into the laser with your remaining eye.
Obviously light in that wavelength range is problematic.

I'm looking forward to when...

[maroberts]

the scanner is combined with Google Glass and dirty old (and young) men everywhere will rejoice!

DNA resonance

[Anonymous Coward]

THz radiation may cause DNA resonance:

http://science.slashdot.org/story/09/10/30/1216230/how-terahertz-waves-tear-apart-dna

Re:DNA resonance

[serent]

In 2011, a further study was done that indicated that under normal circumstances, this theoretical danger shouldn't be an issue, but recommended rigorous experimentation to confirm this:

Modelling DNA Response to THz Radiation
http://arxiv.org/abs/1012.4153

The long and short of it is, it's probably ok but if we're going to start putting them in cell phones, further studying should be done.

Re:DNA resonance

[lightknight]

How about if we stick someone in a machine, with it locked in full-power constant scanning mode, for a month?

Re:DNA resonance

[Anonymous Coward]

That research was performed by Eric S. Swanson: http://fafnir.phyast.pitt.edu/web/swanson.html

"My research is supported by the Department of Energy ..."

THz waves safe? At first, hope...then they studied

[Anonymous Coward]

Not safe...
http://adsabs.harvard.edu/abs/2010PhLA..374.1214A

Now, google it...find out for yourself.

Re:2 million years of evolution

[cheater512]

We need to petition to get these wavelengths banned. These crazy scientists with their fancy lasers that use these dangerous frequencies must be stopped!

Mock-up

[Monkier]

Here's a quick mock-up of how it will look: http://i.imgur.com/2aA3Z.jpg

Re:Mock-up

[TooMuchToDo]

http://www.tricorderproject.org/

Is it safe?

[careysb]

ZAPHOD: It’s a carbon copy of the Ravenous Bugblatter Beast of Traal - or I’m a Vogon’s Grandmother! ARTHUR: The Ravenous Bugblatter Beast of Traal! Is it safe? [Sound of the Ravenous Bugblatter Beast of Traal salivating] FORD: Oh Yes! It’s perfectly safe - it’s just us who are in trouble.

Re:Is it safe?

[Internal Modem]

It was a book first, you know?

Re:Is it safe?

[Anonymous Coward]

No it wasn't. It was a radio series first.

Re:Is it safe?

[Anonymous Coward]

Actually it was a radio series first, THEN a series of books.

Re:2 million years of evolution

[serbanp]

This is slashdot, after all. Most youngsters are already avoiding this harmful radiation by hiding in their mother's basement...

cheap?

[Anonymous Coward]

I'll believe it when I see it, which is probably not for a very long time. Ultrasounds are still tens of thousands of dollars, and they are mostly done on PC laptops these days. It may be cheap to make the chips, but there is no limit to the amount you can charge for the software,so it's unlikely to be seen in an office near you. Maybe in the hospitals, and large imaging centers though.

Re:cheap?

[Anonymous Coward]

Well, it's not just the cost of the chip, it's the cost of certifying the device as well. Sort of like why the military ends up spending so much money on things which would normally be cheap.

Mostly Harmless

[xQx]

I agree, but we shouldn't use the name "completely safe" until it's tested and proven to be safe.

Why don't we just all agree to call all these technologies "Mostly Harmless" until proven otherwise.

Then there will be no confusion.

And if there is confusion, the idiots who are confused need to learn to read, then read a good book. A good book written by Douglas Adams. Then they will understand. They will understand in exactly the same way that bricks don't.

Re:Mostly Harmless

[__aaltlg1547]

Because even that is a distortion. We should call such technologies "new" and anybody who calls them "safe" should be required to either produce evidence that says it is so or a bond that will be paid to whoever eventually suffers harm due to them.

Re:Mostly Harmless

[Anonymous Coward]

Basic scientific theory indicates that you can never "prove" something to be safe. All you can do is demonstrate that you have not observed any harmful effects to date. Same way that one can never "prove" a theory to be correct, one can only demonstrate that it has correctly predicated all the tests run to date.

The correct statement is not "Mostly Harmless" - the correct statement would "No Known Harmful Effects".

Sadly, this is the same thing they said about DTD ... and then we found that years later people were having reproductive problems (by which time it was too late to undo the effects). If one is going to start subjecting the population at large to a new environmental influence, one really needs a much longer and more detailed study than anything I've heard of being done for these scanners.

Wait a sec...

[Anonymous Coward]

Didn't the DHS make the manufacture of THz Imaging devices illegal (cause it's a security threat)

-73 KJ4IPS

Great, now do something about the rest.

[Anonymous Coward]

Great and all dentists can do that but Id rather they update dentistry to something beyond the savage poking, prodding, drilling, gum bleeding, ear splitting and pain inducing deplaqueing water jets and so on. Ill take a xray to the face if it means Im not forced to undergo torture Im paying for just to get my teeth cleaned.

paramedics

[Karmashock]

Imagine if EMTs could get a decent body scan before you've even arrived at the hospital. Doctors could receive a patient having already spent a few minutes going over the scans prior to their arrival.

Re:paramedics

[Greyfox]

Yeah. They'd be all like "Yep! That's a table lamp all right! How did he get it in THERE?"

Better Late than Never

[NEDHead]

I've been waiting a long time for the 'X-Ray' glasses in the back of Boy's Life to actually work. No matter how many pair I bought, or how hard I squinted, they never did the job.

Re:hell yeah, dentists!

[formfeed]

If your dentist is subjecting you to excruciating pain, I suggest you find a different dentist. Most dental procedures are completely pain-free these days.

There is this dentist who uses a manual drill while inhaling nitrous oxide himself and laughing uncontrollably.
-But then again, there is also this nice portrayal of a dentist in the Marathon Man

Re:Communist

[anon208]

I was with you up to green, but red is a menace! It's a RED menace.

Medical Utility?

[izomiac]

I'm a little curious about the medical uses for the technology. Terahertz EM radiation should have similar wavelengths to Ultrasound, which only penetrates a few inches and lacks resolution. It's very useful, don't get me wrong, but no replacement for X-rays, CT, or MRI (click for images of kidney stones using each modality). Plus, ultrasound is becoming even less reliable due to the obesity epidemic, as it can't penetrate a foot of fat very well. Per Wikipedia THz can penetrate low-water tissue several millimeters, which is similar to visible light seen by the unaided eye.

Dermatologists and Dentists may find it useful, but I'm having trouble seeing the application into other medical fields. (Someone can chime in if there's something, I haven't been keeping up on it.) IMHO, it's premature to consider installing these in the clinic. Before that happens there needs to be some unique and significant benefit, which outweighs the risks, and is cost effective. Until then, keep it in the research labs where portability and miniaturization is less of an issue. We don't need technology in the clinic for technology's sake, it just drives up costs and increases wait times.

Re:Medical Utility?

[ColdWetDog]

Yeah, I'm missing something (or the articles are off base). Terahertz EM should have LESS penetration than ultrasound. Maybe looking at the surface of teeth would be useful, looking at everyone's subcutaneous fat, not so much.

Anyone of the Physics persuasion care to enlighten us (so to speak)?

Re:Medical Utility?

[Anonymous Coward]

A couple of points:

Ultrasound is mechanical oscillation, not electromagnetic radiation, so this is a useless comparison. (Ultrasound propagates a long way through dense metal that would block THz at the surface; THz propagates indefinitely through vacuum, which won't conduct ultrasound at all.)

...but, no, THz won't go very deep into tissue. It's probably not a breakthrough for cardiology, but it sure could be for dermatology.

Re:Medical Utility?

[Ungrounded Lightning]

Terahertz EM radiation should have similar wavelengths to Ultrasound, which only penetrates a few inches and lacks resolution.

Actually, resolution using synthetic aperture techniques is very high. In principle (if I understand this correctly) it is an analytical solution and limited only by things like the sampling resolution, timing accuracy, and uncertainty principle, while practical equipment can resolve to far less than a wavelength.

It's INcoherent illumination that is suffers mightily from diffraction limits. Coherent processing preserves phase information and can compute out such artifacts.

Re:Medical Utility?

[ceoyoyo]

THz (and microwave) may be useful for looking at things like possible skin and breast cancers because the tumor tissue has different EM properties than normal tissue.

TSA hailed as the new NASA

[Anonymous Coward]

With such amazing spin-off technology being developed, the loss of American freedoms and $$$ is well worth it /sarcasm

2 milliwatts!

[__aaltlg1547]

The chip that the original article mentions has a PLL and an integrated transmitting antenna and produces 2 mW. That IS safe, but not useful for doctor's office scanners. To be useful for scanners, they're going to have to amp it up by at least 20 dB (probably a lot more) and irradiate the part of you they want to examine. And they'll have to add an array of terahertz receivers tuned to the emitter's frequency if they want to do imaging, and the waveform captured by all those receivers is going to have to be downconverted and processed by a computer comparably powerful to the ones they use for ultrasound. And it will have similar resolution to ultrasound, but will be differently reflected within the body because it's an electromagnetic wave not an acoustic one. And it will dissipate rapidly as it passes through the body because its skin depth is going to be about the thickness of your skin. So they'll have to blast the living hell out of you if they want to look at your spleen or inside your head and you'll be wishing they used something that didn't burn your skin quite so much.

just what i was thinking

[fishingmachine]

my doctors and dentists arent creepy enough as it is, i was just thinking how great it would be for them to have handheld scanners with the ability to see through clothing.

Well if THz radation worries you

[Sycraft-fu]

Are you worried by 100 THz radiation? Because that is commonly called "light". The visible spectrum is from about 400-790 THz.

Radiation is only ionizing, and thus cancer causing, when it is high frequency. X-rays (already in use in medicine if you didn't notice) are much higher frequency, they are past visible light, past UV.

Re:Well if THz radation worries you

[lightknight]

Well then, it's perfectly harmless. So you shouldn't mind spending some time in one. Perhaps even some prolonged time. Perhaps you wouldn't mind some parts from the machine being quietly installed into the walls of your domicile.

Feel free to leave your address. And we apologize in advance for the (much) higher power bill.

Re:Well if THz radation worries you

[Nethemas the Great]

Are you familiar with the concept of "resonance"? If not I would suggest that you read up on it. Your microwave operates on that principle after all. As have a large number of disasters been blamed on it from bridges, buildings, rockets, etc.. There is evidence that terahertz radiation resonates DNA. I don't care if it doesn't blast electrons out of my molecules. I care about resonance being established sufficient to destroy physical structures within my body. Things like DNA.

The Last Thing We Need....

[Anonymous Coward]

Is for our lusty dentists to be using these devices to look at our teeth naked!

Re:The Last Thing We Need....

[Anonymous Coward]

I just hope they delete the photos afterwards, the TSA sure doesn't.

with regulation, licensing and inspection

[gerardrj]

However completely unlike the airport scanners these devices will need to clear FDA and FCC regulations and inspection/testing. The people who operate them will have to take classes and be certified and licensed to operate the device. The devices themselves will be licensed and inspected on a regular basis by the state boards of health.

None of this is seems true for the airport systems.

Re:with regulation, licensing and inspection

[Anonymous Coward]

In order to make an image some of the photons (or waves...) pass through an object (you) while some strike atomic nucleus and are absorbed or deflected, and some of the nuclei are broken apart. This is called ionizing radiation, because ions are formed. All ionizing radiation poses a risk, period. At low levels, the risk is mutagenic and carcinogenic via damage to DNA. At high levels the risks are burns or radiation sickness, which are pretty much irrelevant to uses in doctors offices. These new devices may put out lower amounts or different kMas (1000 volts times milli-amps per second) that may result in a lower risk of mutations and cancer compared to existing medical x-rays technology.

The current risks in doctor's offices from diagnostic x-rays (excluding the rare case requiring multiple repeat studies) can be thought of as clinical or epidemiological. Clinical is singular. The risk to a single patient patient from diagnostic x-rays in doctors offices is close enough to zero to consider it zero. However, if we give 10,000,000 people a standard lumbar series of 5 views, that will cause 1 to 25 cancers (in the 1980's, when my radiology operators license was last in effect. Newer non-film base technologies use maybe 25% of the radiation that is used in film x-ray, so the risk is lower). 10 million mammograms will cause so many cancers. All the hoopla of recommending when a woman should start getting mammograms, for example, was trying to determine when the test was finding more cancers than it was finding. Because the risks are so low, the numbers bounce up and down with each attempt to calculate them. But they are real.

Now, unless the laws of physics have changed, any, repeat, any x-ray exposure to humans will cause cancers and mutations. This includes this new technology. Depending on how and when it is applied, the benefits may outweigh risks. And, human nature being what it is, if thought to be so safe (reminds me of "too cheap to meter," I guess) that we can ignore safety issues, then people will us so much of it it will end up defeating any benefit.

A similar example: if you give police forces "non-lethal" weapons, like Tazers and bean bag guns, there is the risk that the weapons will be 'overused' because, in he eyes of some, "no death equals no harm," or "I can probably get away using this thing, but I certainly won't get away with shooting this punk." Less inherent risk in a technology does not equal more safety if it is thought of as a license to use it while ignoring the risk there is.

Re:with regulation, licensing and inspection

[Neil Boekend]

I'm not saying it's safe, but it isn't X-ray and it isn't ionising radiation.
It's between microwave and infra red.
If you go up in frequency from Thz, the first frequencies you encounter are infra red. Then visible light. After you go up from that you get UV. And if you go up in frequecy from that you get X rays.
THz scanners may pose a threat, but it's not ionising and thus it poses a different threat (if any)

Re:with regulation, licensing and inspection

[Anonymous Coward]

Actually, this comment made me think -- and now I'm wholeheartedly in favor of this.

The TSA certainly wouldn't admit to any problems, even if they exist and are severe. But if the scanners _are_ dangerous for some reason, the FDA and FCC inspection/testing will hopefully reveal that, and we'll find out.

And then, hopefully, there will be some hard questions asked, like 'Why didn't the TSA find this?' and 'Why was the TSA claiming these were perfectly safe?'

(To be honest, I suspect there won't be any serious issues, but "don't know" means "don't know", not "no problem".)

Re:with regulation, licensing and inspection

[ceoyoyo]

You are wrong. In a THz scan some photons are absorbed or scattered while others are reflected. You measure the reflected ones. Ionizing radiation has the ability to excite electrons enough that they can escape from their atoms, producing charged nuclei. Ionizing radiation doesn't break up nuclei.

THz photons are not high enough energy to knock out electrons. It is not ionizing.

Re:2 million years of evolution

[Anonymous Coward]

No to mention, the fact that going to the dentist is already bad enough without having to go through a pat down and strip search.. Keep TSA out of my mouth!!!

Re:THz waves safe? At first, hope...then they stud

[Anonymous Coward]

So, apparently, real science doesn't ring a bell...here on the nerd channel...

Re:hell yeah, dentists!

[Anonymous Coward]

Dude, that's fucked up!

Hand-held CT scanner

[Animats]

The next step, once there's terahertz scanning capability in a hand-held device, is to add an accurate short-range location system to the device. Then it becomes possible to do most of the job of a CT scanner, building up a 3D image, with a hand-held device and a lot of compute power. This will be a big win for medicine.

It might be sufficient to put a 6-axis IMU chip in the device and use SLAM to correct for cumulative error. Then you could reference to the body being scanned, not the world coordinate system, and get clean scans even if the patient moves a little.

A useful marketing strategy would be to deploy this first for veterinarians. This avoids many of the regulatory issues.

Re:Hand-held CT scanner

[Beryllium Sphere(tm)]

Some industrial and mechanical applications might also be good early adopters. No "medical device" overhead to deal with, and a good-sized market.

Re:Hand-held CT scanner

[Anonymous Coward]

The true next step is putting it in mobiles to make the more obscure apps work for real.

Re:Hand-held CT scanner

[ceoyoyo]

Nope. THz waves don't penetrate much. You measure scatter. CT requires projection images.

You could potentially get limited 3Dish data on things near the surface, but that's of limited value and probably not worth the cost and complexity

Salkl bir cilde sahip olmak istermisiniz?

[kadincayorum]

http://www.kadincayorum.net/saglikli-bir-cilde-sahip-olmak-ister-misiniz-t175.0.html

I can't honestly decide which is funnier.

[Anonymous Coward]

Especially in the 400nm to 700nm range.

I can't honestly decide which is funnier.

Your joke, or the fact that it whoosh'd past all the slashdot moderators as they eagerly dolled out +1 insightfuls.

Re:I can't honestly decide which is funnier.

[lightknight]

As others have pointed out, consider a powerful laser operating at that frequency.

Of course, that could be used to someone's benefit -> "Now Bob, they're going to play a trick on you down at the high-energy lab, and tell you that you shouldn't walk in front of their laser; but Bob, have you ever heard of blue light, even a very bright blue light (like at that club), ever hurting anyone? Of course not; so I figure we can one up them if you show them you know about their trick by walking in front of their big blue laser when it's on. Show that you're not afraid, 'cause you got nothing to be scared from an overgrown night-light."

Re:I can't honestly decide which is funnier.

[cheater512]

I think the +5 Insightful has more to do with how plausible it is to say that and loonies would believe it, rather than the moderators believing in it themselves.

At least I sure hope that.

Famous last words

[michelcolman]

It's completely safe!

Re:Famous last words

[nospam007]

Yes, technology that can't see a knife behind a pancake pasted onto a stomach is the way to go.

No reason to be concerned?

[tlambert]

Given the fundamentals here there is no reason to be concerned about the safety of terahertz radiation. It is certainly far safer than the alternatives which have large known risks.

Unless you have an insulin pump.

http://www.inquisitr.com/233195/tsa-breaks-teens-insulin-pump-during-forced-full-body-scanner-examination/

Then it's pretty damn dangerous, particularly if it happens to be on when the scanner kills the control circuitry for the pump.

Re:No reason to be concerned?

[lightknight]

Which, arguably, is almost as dangerous as if the TSA mistakes the insulin pump for a bomb.

Re:2 million years of evolution

[Frisno]

The dentist will allow you to opt out, in favour for a traditional cavity search.

"Completely Safe", my cute lily-white ass!

[Jane Q. Public]

There is very good evidence that terahertz waves are anything but safe!

Whereas X-rays pass through most body parts, leading to a very low rate of absorption that is also spread throughout most of the body, terahertz waves are the opposite: a minority of the radiation is reflected back to the scanner, but the majority is completely absorbed by the tissue at the depth of penetration. And because that depth is pretty specific, what you have is a very thin layer of tissue that is completely absorbing a great deal of energy from the radiation.

If you really think about that, you will change your mind about any "completely safe" claims. We need tests and more tests and double-blind tests, before it can be declared "safe", and even then we would need to wait for a long time to rule out any possible long-term effects.

Re:"Completely Safe", my cute lily-white ass!

[ericloewe]

You're missing the really big difference: X-rays are ionizing, terahertz radiation is not. There's a very simple solution to that problem: don't use too much power. Anyone will feel major discomfort before any sort of damage happens.

Re:"Completely Safe", my cute lily-white ass!

[Anonymous Coward]

UV isn't ionizing, either, but prolonged exposure leads to skin cancer.

Re:"Completely Safe", my cute lily-white ass!

[Anonymous Coward]

To be clear, I consider the body scanners to be an exploitation of irrational public fear for corporate profit and political power mongering.

However, the statement that "they must be harmful because it is being absorbed" has no scientific merit on its own. We absorb "radiation" all the time, mostly in the form of heat. The question is what effect does the absorption cause? If it is just mild heat, it is unlikely to be harmful. If it causes ionization (which is what x-rays and some other forms of radiation do) then it can be harmful.

I do agree that prior to subjecting a large portion of our population to a new environmental influence we need to run better and more detailed longitudinal studies.

Re:"Completely Safe", my cute lily-white ass!

[Anonymous Coward]

You're missing the really big difference: X-rays are ionizing, terahertz radiation is not. There's a very simple solution to that problem: don't use too much power. Anyone will feel major discomfort before any sort of damage happens.

Any time I have to deal with the TSA I feel major discomfort. Does this mean I have cancer?

Re:"Completely Safe", my cute lily-white ass!

[ceoyoyo]

Everything you've said applies, more so, to the radiation from household lightbulbs, cfls or LEDs, which also emit at much higher power and energy levels.

Re:"Completely Safe", my cute lily-white ass!

[ericloewe]

It's not ionizing, but it's energetic enough to break chemical bonds. Terahertz waves aren't.

Re:"Completely Safe", my cute lily-white ass!

[Jane Q. Public]

"You're missing the really big difference: X-rays are ionizing, terahertz radiation is not. There's a very simple solution to that problem: don't use too much power. Anyone will feel major discomfort before any sort of damage happens."

(Cough, cough.) Ahem. Microwaves are non-ionizing too, fool. But I'm using them to cook my breakfast.

Re:"Completely Safe", my cute lily-white ass!

[Jane Q. Public]

They're higher frequency than microwaves, which are used to cook food.

But no... that couldn't possibly be harmful, could it?

Re:"Completely Safe", my cute lily-white ass!

[Jane Q. Public]

I should qualify that. Your point about discomfort MAY be valid, but maybe not. I think it would depend on the depth of the absorption.

But my point was this: the depth of penetration is apparently pretty specific, otherwise it wouldn't be very useful for imaging. Which means absorption is going to be at a specific depth, too. Which means it isn't being absorbed by a great mass of tissue, like other kinds of radiation might: instead, it is all being absorbed by an extremely thin layer.

Re:"Completely Safe", my cute lily-white ass!

[ericloewe]

How powerful is your microwave? 900W? I'd say that's way too much power.
Same thing as saying light is dangerous because very powerful lights can burn you.

Re:"Completely Safe", my cute lily-white ass!

[ericloewe]

Of course it's harmful if you use 900W to scan someone.

If it is safe, then it won't replace X ray

[Anonymous Coward]

The reason we use xray at the dentist for example is to look at the density of bones for various lesion and holes, or how the root grow etc.... Nothing the terrahertz technology can really replace. There is a reason we have various tech which look at various depth, and various material density. For example MRI did not replace Xray either. Or even computer tomography. It *might* replace some imaging technic, but don't expect a miracle here.

Re:If it is safe, then it won't replace X ray

[Ungrounded Lightning]

The reason we use xray at the dentist for example is to look at the density of bones for various lesion and holes, or how the root grow etc....

And the reason that's what we look for is because we CAN. That's what X-rays do that's useful.

Nothing the terrahertz technology can really replace.

Though it does it somewhat differently, it may be able to do at least some of those. Perhaps even something good enough to replace all of them. And it may be able to do other useful things that X-rays don't.

Right now they just got a transmitter and receiver working on a chip. Let's hang in there until they get some systems built up and see what can be practically engineered.

Incorrect

[aepervius]

"The radiation is too high-frequency to excite any of the electrons orbiting the atoms in the human body (which is how UV causes damage)"

You meant too LOW frequency , as terahertz is about order of magnitude of micrometer of wavelength : it is in the infrared part of the spectra (far or near depending on how many THz we are speaking of). In fact frequency is going from very low (VHF->FIF->NIF->Visible) to very high (Blue->UV->X->Gamma). Higher frequency=High energy is bad as it can easily knock electron off orbits. Low Frequency=Low Energy less dangerous, to even inactive on our body. Which is the invert with wavelength (short wave =very dangerous , very long wave think radio BHV etc harmless). Then there is also the question of quantity, but as a rule of thumb it is enough.

Re:Incorrect

[Samantha Wright]

Crap; sorry. You got me. I would've caught that if I'd read it more carefully. You deserve some mod points for that.

Re:Incorrect

[chihowa]

Stare into a gigahertz waveguide for a few seconds and we'll see how harmless "low" frequency signals are (these are obviously even lower than terahertz and you will go blind).

If we reconstitute your post with the bits that would lead it to make some sort of sense, I assume you're talking about microwave heating. In that case, this was already addressed: "...it will warm you up if left on for too long..." The eyes in particular are bad at removing heat because of the lack of blood in much of them. Anyway, it'd take a lot of microwaves to cause any damage. Taping your wifi router to your eye will hurt you, but only because taping stuff to your eye hurts.

Re:2 million years of evolution

[Anonymous Coward]

It's not just of the hands of those crazy scientists we need to keep those fancy lasers out. Don't forget about the sharks.

(I didn't want to end sentence with a preposition if that sounds weird.)

Re:2 million years of evolution

[Anonymous Coward]

Look into the laser with your remaining eye, and you never have to worry about these frequencies again.

Re:2 million years of evolution

[Arancaytar]

... +10^10 internets.

Re:2 million years of evolution

[Anonymous Coward]

They may be in the basement, but think of the glow of those screens.

Re:2 million years of evolution

[Anonymous Coward]

Except that basements in some parts of the world can have high concentrations of radon....

regulations

[Anonymous Coward]

The best part is that they will be subject to FDA regulation. Probably things like maximum intensity levels, maximum dose over a given period, restrictions on use for pregnant women and infants, requirements for training of operators and periodic inspection of the machine. And then we can see how those requirements will totally fail to match up to the current usage of airport machines.

I bet...

[wcrowe]

...what is free at the airport will soon cost $2,000 at your doctor's office.

Re:I bet...

[Anonymous Coward]

...what is free at the airport will soon cost $2,000 at your doctor's office.

Who pays for the body scans at the airport though?

Re:hell yeah, dentists!

[lightknight]

Yes, but the question stands: Is it safe?

Re:Bah! I preffer the good old days!

[lightknight]

The federal market for these machines is tapped out? And the associated businesses like money?

Re:2 million years of evolution

[Anonymous Coward]

Um... UV rays are also Thz waves, and are clearly known to cause skin cancer.
So no, I'd say that the whole 'completely safe' thing is not just a given.

Some of the scanners may be safe.

[Wild_dog!]

A big chunk of them are xray scanners.
It isn't the scanner working under normal conditions that would worry me so much.
But if it malfunctions and spews out lots of radiation all over the airport, that might worry me.
I still won't go through them or have my kids go through them.

Dental Naked Scanner

[Jellodyne]

Giving your dentist the ability to take naked photos of you with a scanner is probably better than the old where he used anesthetic.

No.

[Ungrounded Lightning]

Didn't these used to say that X-rays were safe?

No.

As another poster has already mentioned: The discoverers of X-rays warned from the beginning that there might be harm, and reports of damage from exposure were in the literature within the first couple years.

(Now some people may have said, somewhere along the way, that some level of X-rays is safe. Manufacturers and users of X-ray equipment, for example. B-) )

TSA and arrests.

[Ungrounded Lightning]

All the TSA agent has to do is point at you (well, with some reason of course), and the cops would arrest you.

Also, once you come into view of the checkpoint you are not allowed to leave without permission and may be detained if you try.

Assaulting a TSA agent would not be considered assaulting a police office[r]...

Agreed, "assaulting a peace officer" wouldn't apply. But don't they also have a separate special charge for screwing around with TSA people and operations, similar to the post-9/11 "interfering with a flight crew" prohibition?

Re:TSA and arrests.

[CelticWhisper]

They do - "Interfering with the screening process." They threaten fines of up to $11,000, but it's done via a civil lawsuit and to date, they've never successfully applied it. I get the distinct impression it's one of those things they don't want to see looked at too closely in court because it would crumble easily. Better to keep it uncertain so they can harass the traveling public with the threat of it. Officious Nazi pigfuckers.

Medical applications are extremly doubtful

[Crio]

First, this frequency range is absorbed by water very, very effectively (fractions of a milimiter is enough to shut it out completely) and man is mainly water. So it can see just under the skin. Then - resolution. 390 GHz has wavelength of about a millimeter - not much to see in a human tooth. At last - power. 2 microwatts is not much, it is not much at all. There is no very sensitive detectors without cryogenic cooling, so ...
We have some time to figure out is terahertz radiation really safe.

X-ray goggles!

[Anonymous Coward]

Is anybody concerned about having hand-held devices that can see through clothing? I mean, x-ray goggles are going to be a reality...

Re:2 million years of evolution

[dragisha]

Yeah we need far more testing on radiation. Especially in the 400nm to 700nm range.

Sure they say its perfectly safe but how long have we been exposing ourselves to it? More data is required!

Together with dihydrogen monoxide.

World would be much better off without such radiation and substances.

Re:2 million years of evolution

[LinuxIsGarbage]

The dentist will allow you to opt out, in favour for a traditional cavity search.

I actually did laugh out loud for this one. I almost had wine out my nose. I had mod points but it was already +5.

To All Who Took Exception To My Comment

[Jane Q. Public]

The safety of any kind of radiation should be DEMONSTRATED before every being used on human bodies, especially on a large scale!

I am aware that there are reasons to be skeptical about any damage being done, but we have, many times in the past, been surprised to find that things we previously thought harmless were in fact very dangerous.

Example: X-Rays were initially not thought to be especially harmful, but we eventually learned that it very much was. True, it didn't take very long before X-Rays were looked at with increasing caution, but that was the exception.

The Curies themselves died of radiation poisoning. Even so, workers in plants that made radium watch dials continued to get sick and die in abnormal numbers, for decades, before the practice was stopped.

Tanning beds are now known to be harmful, even though they were touted as using "safe" forms of UV, just a few short years ago.

Sub-millimeter radiation has been studied for how long now? It has been in widespread use for how long?

SHOW that it is safe, or at least relatively safe, and I'll drop my objections. Until then, I'll keep them. Saying that it's safe merely because it's "low power" doesn't cut it.

Besides: aren't we forgetting the main thing? These scanners are proven to be incapable of effectively performing the function they are used for. So why are we debating this at all?