Lishtot - Test If ANY Water Source Is Safe To Drink In 2 Seconds

[amyk]

"richlorophenol" - that's rich!

The fact that they don't even bother proofreading their site already says volumes about how much they should be trusted

[magic]

https://www.lishtot.com/coming_soon.html

They also have an improved version which can list the exact contaminants it found and their concentration level. Coming soon in 2018

Of course you must sell your soul to The Cloud and they monitor your every move to sell the data you collected to third parties

edit
On the upside, at least they have some marketing team which monitors the Internet for threads like this. Savvy

 

[Cyberdragon]

On the upside, at least they have some marketing team which monitors the Internet for threads like this. Savvy

 

Perhaps they saw what happened to the "digital electricity" guy, saw that this is 100 times more BS, and realized immediately what would happen to them.

Come on scammers...show yourselves...we have our logic cannons armed and ready.

[Xenoamor]

I'm not a chemist but wouldn't this at least need to be placed in the water to even stand a chance at doing something?
It's Thanos 2 for water, with wireless tech!

That gif on their site looks sketchy as well. Looks like they hold the button down and it blinks and then when they release it it shows the "results", very easy to fake but if they're selling something it should be a laugh to have a teardown of it

[taydin]

Question to the folks here that know water quality measurement: What kind of unsafe contamination CAN BE detected using an electronic device, and without water contact? (not this device, I'm talking generally).

[wraper]

Question to the folks here that know water quality measurement: What kind of unsafe contamination CAN BE detected using an electronic device, and without water contact? (not this device, I'm talking generally).

You can use XRF to detect chemical elements (not chemical compounds) without contact. But its problematic detecting elements with low atomic number and very small concentrations for point-and-shoot systems. Also you can detect radiation, though without close contact sensitivity will be crappy.

[fcb]

UV fluorescence can detect stuff that absorbs/re-emits UV  light (oils work well). Absorption spectroscopy (using light) is quite a common technique for water analysis.  You can even do atomic absorption spectroscopy.

[Cerebus]

Question to the folks here that know water quality measurement: What kind of unsafe contamination CAN BE detected using an electronic device, and without water contact? (not this device, I'm talking generally).

I know nothing more than the average man about water quality measurement specifically, but I've a fair grasp of some of the potentially applicable laboratory techniques from Physics, Chemistry and Biochemistry.

You can probably detect more than one might at first think with 'non-contact' methods, but not necessarily economically.

Things I can think of offhand - most of these require you to contain a sample in a flow tube or sample cell so are non-contact only in the strict sense that the sensors aren't in contact with the liquid under test:

• Radioactivity - scintillation, Geiger-Müller tubes, semiconductor sensors
• Turbidity - i.e cloudiness - optical scattering sensors
• Colour changes visible and otherwise - optical spectroscopy basically. Everything from obvious visible 'off' colours like iron contamination to compounds that can be reliably detected via (relatively expensive) IR and UV spectroscopy. IR and UV spectroscopy are standard tools for chemists and can identify potentially a large range of compounds.
• Total dissolved solids - electric field measurements. This seems to be the territory of the device in question. Measurement by the effect of solutes on the field behaviour of a water sample would be incredibly fickle and inaccurate compared to the standard method which is resistance/conductivity testing using contact probes.
• The final non-contact detection techniques I can think of are Electron Spin Resonance and Nucleo-magnetic Resonance. (ESR and NMR). Both quite expensive generally requiring cryo-cooled magnets but ESR is potentially quite a powerful technique for identifying substances. Chemists use ESR to watch reactions in progress.
• If you're going to allow vapour phase sampling as 'non-contact' I think we could include Mass Spectrometry and Gas Chromatography both individually and in tandem as GC/Mass-Spec. Massively powerful technique for identifying mixtures of compounds, expensive, with uncontrolled sampling I suspect this would be prone to contamination from things in the sample stream. Stretching the 'non-contact' idea a bit here.

The problem here is differentiating between harmful and harmless contamination. Turbidity testing will tell you if a sample's cloudy, but not of that cloudiness is from some particles of harmless chalk (calcium carbonate) or harmful white lead oxide. Spectroscopy might reliably detect and differentiate some harmful organic compounds from harmless. None of these techniques could tell the difference at any useful level of sensitivity between harmless soil bacteria and harmful cholera bacteria, ditto tobacco mosaic virus or a T4 bacteriophage* and ebola. 

* My favourite type of virus:


A visualisation of a T4 bacteriophage about to infect a single bacterium.

Edited to add: Also available as a cuddly toy

[EEVblog]

You can probably detect more than one might at first think with 'non-contact' methods, but not necessarily economically.

Or reliably with measurement of charge on a surface, and that's why this product and method is ridiculous.
Even if the contaminants produced the charge as claimed, to try and reliably detect the charge on a cups surface is comical.
This is why their own website and videos are filled with finicky details of how not to screw up the measurement.

[Cerebus]

You can probably detect more than one might at first think with 'non-contact' methods, but not necessarily economically.

Or reliably with measurement of charge on a surface, and that's why this product and method is ridiculous.
Even if the contaminants produced the charge as claimed, to try and reliably detect the charge on a cups surface is comical.
This is why their own website and videos are filled with finicky details of how not to screw up the measurement.

I'd go further and say that detecting ionic changes by measuring surface charge falls into the 'plausible, but not proven' category. If it works it will be, as I said previously, "incredibly fickle and inaccurate".

That their method insists on having a fresh, clean, unused plastic glass handy, but their publicity shots show people kneeling to test river water out in the wilds (presumably in deepest, darkest, adventuresome Africa) is an interesting contrast. I wonder how they would defend that particular juxtaposition.

When I was younger and my knees still worked properly I spent quite a lot of time walking in the wilds away from civilisation and given the choice between a couple of pairs of dry socks with something to eat or a stack of unused, clean plastic beakers, I know which I would choose to cart around with me. Moreover, anyone who's spent any time in the wilds will know that, depending on where you are, the contents of your rucksack* are either permanently damp, or full of dust. Not much hope of keeping your precious stack of virgin beakers clean and/or dry.

Perhaps I'm a poor man to judge - I've spent the majority of my backwoods walking days in either Scotland or Wales, both places where if you need clean fresh drinking water you just point your face upwards and open your mouth. 

* When I was typing this I somehow managed to type "rucksuck" instead of "rucksack". Given the amount of water that some of mine have accumulated inside their bottoms I think the typo might be more appropriate.

[Lishtot]

Some healthy skepticism has been raised on this forum regarding the Lishtot TestDrop Pro and its method of performance.  This post is to help explain how the device works and the science behinds its design.

Water has been shown to be a triboelectric material, namely it can deliver electrons (primarily from hydroxide ion, it would appear) to a wide range of materials.  Below are links to two academic papers and one US patent that are based on the triboelectric behavior of water with plastic materials.  It is noted in the first reference that water would be only less positive than air in a proper ranking of materials in a standard triboelectric series.

https://www.sciencedirect.com/science/article/abs/pii/S030438861630002X
https://www.sciencedirect.com/science/article/abs/pii/S0304388611001100
https://patents.google.com/patent/US4594553A/en

As noted in the above references, water imparts a charge on plastic materials by virtue of contact between water and the same, just as a person gets charged up by walking on a rug in the winter.  The static charge deposited on the plastic has associated with it an electric field.  The prior art work cited above measured the charge delivered to the plastic generally with two electrodes.

One important outcome from the second reference was the inadvertent realization that the size of the field associated with charge delivered would be related to what was present in the water.  The graphs below are from the Ravelo paper:





Note the Y-axis labels.  The distilled water has a range from 0-250 mV, while the "ordinary water" has a scale of 0-40 mV.  The Ravelo paper was the first to give an inkling that the amount of charge transferred from water to a plastic material was directly related to what was present in the water, or in other words, water quality.
The TestDrop Pro currently has three US patents associated with it:

https://patents.google.com/patent/US9453810B2/
https://patents.google.com/patent/US10240182B2/
https://patents.google.com/patent/US10060895B2/


The basic function of the device is to run an unpowered electrode through the electric field generated on a plastic surface by electrons delivered from water.  The device makes 100 measurements per second and by moving one device towards a cup with water, we can get a large number of data points in only a few seconds.  As one would expect, as the device gets closer to a cup with water, the electric field becomes stronger. Below is a canonical graph of "clean water".  Note that as the device moves towards the cup (represented by time in seconds on the X-axis), the field becomes more and more negative.
 




This result is completely consistent with the data from the three prior art publications cited above.  Water is a triboelectric material.  When contacted to a plastic surface, it transfers electrons to the plastic.  A static electric charge will have an electric field associated with it.  An unpowered electrode moving towards a source of static electricity will record stronger and stronger negative electric fields as it approaches the charged-up plastic.

So we can make a measurement that is related to water's interaction with plastic.  This interaction has been seen with a wide range of plastic materials in different formats such as cups, bottles, pipette tips, disposable pipettes, etc. So how does one get discrimination?  Or more accurately, why would water samples give different signals that allow for identification of contaminated samples?

The TestDrop Pro is trained to identify clean water samples, namely those that have profiles similar to the one shown above.  One can program the device for different levels of sensitivity but the general concept is that clean water allows for a lot of charge to be transferred to a plastic container or material.  When water is contaminated, fewer electrons reach the plastic.  Why?  Essentially, there appear to be two different reasons:

1.  Inorganic contaminants such as heavy metals appear to coordinate hydroxide and make electron release to plastic more difficult.
2. Organic/biological contaminants bind to plastic near the waterline and due to their association with water via hydration and/or hydrogen bonding effectively extend the waterline higher up in the cup or container.

The current protocol for the TestDrop Pro has measurement of electric field in the open space over the waterline. The reasoning is that this is where one should fiend lots of electrons transferred by water after swirling, without interference of the now positive water and any contributions from whatever its contents may be.  If fewer electrons are transferred to the plastic, the resulting fields are weaker, as shown in the graph below for a sample that included sodium hypochlorite ("bleach") and ppb levels of lead as free divalent ion:
 


The algorithm associated with TestDrop Pro is designed to look for a certain percentage of a graph below a predetermined threshold.  In the above graph, the lead/chlorine sample does not pass that threshold and the sample would be flagged as contaminated.
As mentioned above, the water, missing electrons left on the plastic, becomes positively charged due to unbalanced hydronium ions (hydroxyl radical is neutral).  Below is a graph of approaching the cup, this time below the waterline:
 



Organic/biological samples tend to wipe out signal until the concentration of the contaminant is very low, ppb or less. Below is a graph for suspected carcinogen PFOS in tap water.
 


The performance of the device as a screen for inorganic and organic contaminants allows for rapid determination of whether a water sample needs further laboratory attention.  Below are links to testing performed outside of Lishtot's labs with the TestDrop Pro. We were not involved in any of the testing reported by Analiza or MIT. Additional companies and research labs have performed research under nondisclosure agreements.

https://www.lishtot.com/reports/180108 Lishtot TestDrop Pro - PFOS - FINAL.pdf

https://www.lishtot.com/reports/180105 Lishtot TestDrop Pro - Protein - FINAL - AB AK Signed.pdf

https://www.lishtot.com/LishtotAnalysis_Nepal_Experimental_Plan-Lishtot_TestDropPro_Jan201


For additional information, please visit https://www.lishtot.com/

[KaneTW]

This still doesn't really answer my questions about selectivity: Can you tell apart harmful from harmless contaminants? How well does this device perform using tap water or similar?

All of these tests were using ultrapure water as control and one single contaminant added. This is utterly unrealistic for any actual scenario. Even tap water contains up to 1.5 mg/l of total organic carbon.

[Cerebus]

You say:

The TestDrop Pro is trained to identify clean water samples, namely those that have profiles similar to the one shown above.  One can program the device for different levels of sensitivity but the general concept is that clean water allows for a lot of charge to be transferred to a plastic container or material.  When water is contaminated, fewer electrons reach the plastic.  Why?  Essentially, there appear to be two different reasons:

1.  Inorganic contaminants such as heavy metals appear to coordinate hydroxide and make electron release to plastic more difficult.
2. Organic/biological contaminants bind to plastic near the waterline and due to their association with water via hydration and/or hydrogen bonding effectively extend the waterline higher up in the cup or container.

Let's just take those as a given. I suspect that few of us who've thought about it have any quibbles that both the above conditions can make a measurable difference to the electric field generated by sloshing water against a dielectric such as the PET or Polypropylene that plastic cups are made of.

At issue is whether this device can differentiate between:

• harmful inorganic solutes such as lead, mercury, cadmium
• harmless inorganic solutes such as calcium, magnesium, chloride.

or differentiate between

• harmful concentrations of organic solutes such as PFOA or protein from pathogens such as cholera
• harmless concentrations of organic solutes such as ethanol or protein from non-pathogenic soil bacteria

If you can't make those differentiations then this is useless as a water testing device. Yes, it may tell you if the water is different from the sample it has been trained on but that isn't useful if the difference indicated has no practical effect as to safety, potability etc. I see no reason why this device, if it is sensitive enough to detect unacceptable lead or cadmium concentrations, isn't going to 'alarm' at hard water if it has been trained on soft water or vice versa.

The clear suggestion from your marketing materials is that this device is suitable for field use for testing water potability. How realistic is this implied claim when it requires a supply of clean, unused plastic cups/beakers to work - things that are difficult to obtain 'in the field'?

So, to sum up the two questions this raises:

• How is this device useful as a water testing device when it appears to have no selectivity?
• How does the need for a carefully controlled testing setup fit against your implied claims for this as an 'outback' field water testing device stack up against the realities of operating in the field?

[Lishtot]

Selectivity.  The device detects classes of contaminants, namely organic/biological and inorganic, generally but not exclusively (it can detect high levels of hypochlorite, fore example) heavy metals.  If the device detects the presence of contamination, it is detecting something that should not be in drinking water.  This does not necessarily imply danger.  For example, take clean tap water.  It will give a clean signal.  Take a sip and swirl again and you will read contamination.  Your saliva contains many organic compounds that would not be found in clean drinking water.  The sample is not dangerous but it is clearly adulterated.  The device has been tested against sodium, potassium, calcium, magnesium and other typical water components and has been found to be blind to them at concentrations in the molar or higher levels.  The device can alert a user to water that is contaminated.  And do so in a few seconds.  Alternative technologies either take much longer or provide a single answer, for example, a $15 lead test--it won't say a word about bacteria.  Dipsticks are excellent for testing water but we believe that we have a broader range and the device is good for 4,000 tests on a single watch battery.

As to the perfect water conditions used by the prior art scientists, we have on our servers over 200,000 tests run by 5,000 users in 67 countries.  This device has been tested with a tap, filtered, RO, bottled, air-generated, and natural water sources.  They tested distilled water; we test only the real thing.

[Lishtot]

At a first cut, there is no need to differentiate what type of heavy metal is present.  This device is a screen, it presents the first line of defense.  And as such, it can warn a user that there is something in the water that should not be there.  We have demonstrated sensitivity to heavy metals tested in 10-20  ppb (except for copper which is 1.3 ppm) and thus is useful for detecting at relevant concentrations. If a water provider or user wishes for more information, numerous professional labs can provide the same.

The issue of detecting dangerous versus innocuous things is important, but why would expect ethanol in your drinking water?  Safe bacteria would probably not release enough protein to give a signal (we have seen the same for certain strains of E. coli).  If you ppb levels of PFOA or enough bacteria-produced protein to give a signal, I think that you would be grateful to know about it.

As to the perfect water conditions used by the prior art scientists, we have on our servers over 200,000 tests run by 5,000 users in 67 countries.  This device has been tested with a tap, filtered, RO, bottled, air-generated, and natural water sources. 

[Lishtot]

In addition:

As to the issue of field testing, if you had a device, you would notice that there are three buttons.  The one-button is set for a lower level of sensitivity exactly for nature testing.  We are aware that naturally sourced water has its own "natural" contaminants such as dead skin, leaves, bugs, and more.  We are doing our best to provide meaningful information without allowing our users to drink potentially dangerous water.  Natural water is a challenge for us but we still believe that we can provide useful information to our customers.

[AVGresponding]

The graphs at the top for distilled and tap water show a pretty clear linear relationship between the flow rate and the measured voltage.

Therefore I think it's reasonable to assume that unless you can accurately control the flow rate, the reading won't be worth anything anyway.

I fail to see how "swirling" the water around the plastic cup can in any way be considered to be controlled, in a metrological sense of the word.

[Lishtot]

Swirling generates the charge. We have put into the parameters of the device a wide berth for differences in swirling. Still, 5-10 seconds is enough to generate a large field on a polypropylene cup. In our system, there is no flow issue, only time if swirling to generate charge. Walking on a rug is not the same as rubbing your feet hard on the same rug. Please test the device and see for yourself.

[EEVblog]

This still doesn't really answer my questions about selectivity: Can you tell apart harmful from harmless contaminants? How well does this device perform using tap water or similar?
All of these tests were using ultrapure water as control and one single contaminant added. This is utterly unrealistic for any actual scenario. Even tap water contains up to 1.5 mg/l of total organic carbon.

Yep. I'm sure that no one doubts the effect itself is real.
The thing that makes this product fall into the impractical bullshit category is the ability to accurately and repeatably measure this under real world conditions. The marketing claims will always exceed the ability of the device to deliver a practical result.

It's the age old trap that inventors of things like this fall into - they take some actual phenomenon and then proceed to think they can engineer a solution that will actually have a practical and marketable results. Doesn't matter if it's Batteriser, Home energy saver capacitors in a box, ultrasonic wireless charging, infrared wireless charging, Fontus self-filling water bottle, peltier device energy harvesting etc.

No need to test this product, it will eventually die it's natural death, guaranteed by the laws of finicky engineering.

But hey, good luck trying.
I won't waste my time testing this, I know exactly how it's going to go:
I use my surface charge voltmeter to try and measure charge build up on the cup, results are entirely inconsistent and finicky. I come to the conclusion that it kinda-sort-maybe works if you hold your tounge at the right angle under a full moon. Manufacturer claims a new model till make it more robust. I retest that, with similar results. They say I'm not doing it right and just point to the thousands of people using as proof it "works".
No thanks.

[wraper]

They say I'm not doing it right and just point to the thousands of people using as proof it "works".

Those who drank some dodgy water after testing it as OK probably cannot leave feedback from their grave 

[wraper]

BTW don't forget about Theranos with their magical blood test and former billionaire bullshiter Elizabeth Holmes now facing criminal charges.

[SiliconWizard]

I also warned them about potential legal issues earlier... I hope they take this seriously. As always, one of the best "tests" you can do is ask the inventors to give the device to their kids and tell them to go camping without bringing any water, and just tell them to use the device to know what they can safely drink. Let's see how confident they are then. (And to paraphrase one famous song, I hope they love their children too. )

Sure the idea may be interesting as Dave said. But the practicality of it all?

As was discussed above, even if the thing sort of "works" under certain conditions, how can the end-user be certain some random water will be safe to drink with this, as 1/ the reliability of the measurement with "real-world" water is still not completely certain and 2/ as was discussed earlier, it doesn't seem to be able to detect some contaminants. Even if you clearly write which contaminants can be detected and which can't, how is it going to be useful in the field? That was one of my main questions here. How is the user going to know what kind of contaminants the water they want to test may contain? That is kind of a non-sense from a usability POV. Unless of course I missed something.

[magic]

Exactly. I wonder if the CEO would drink any clear liquid flagged as safe by the retail version of this gadget. Heck, even any water sample from wild nature flagged as safe by this gadget. Bonus if the exact same physical unit of the gadget can also detect safe surface water so that you don't die of dehydration

Natural water is a challenge for us but we still believe that we can provide useful information to our customers.

Nice that you admit so, but that's not what you advertising suggests. May we have a screenshot in case shit goes viral and the website is pulled down or edited? There we go



Is it just me or does it look like you imply that MIT found this device to be safe with any water found in the wild? Defo looks like false advertising to me

All the independent certifications you link also have disclaimers that no suitability for any purpose is implied by the lab issuing them. You have zero independent testing to back up your marketing claims as far as we know.

Some healthy skepticism has been raised on this forum regarding the Lishtot TestDrop Pro and its method of performance.

Yes, folks are accusing you of fraud and called your product "a scam"

[Lishtot]

The device works and has been shown to work by researchers, companies, groups, and individuals who have no relationship with Lishtot, and for your question, YES - the CEO would drink any clear liquid flagged as safe by the retail version of the TestDrop. (The difference between Theranos and Lishtot is that Theranos hid all their technology and we are the opposite, we have thousands of customers all over the world that tested it by themselves).

The device is not perfect and like all such devices have an error rate of false positives and negatives, which we have found to be less than 10% at the concentrations of contaminants shown on our website (clean water shown as not, less than 5%).  That said, our performance is similar to water testing kits in this market and offers advantages of re-usability, speed, and breadth of contaminants to give a warning to a user. For more on water testing kits, please see this link: https://www.lishtot.com/Water-testing-kit.html
 
The disclaimer on our website is standard - we believe in our product and stand behind it.  Do you know that ALL water filter manuals state the following or thereabouts:
"Do not use with water that is microbiologically unsafe or of unknown quality without adequate disinfection before or after the system." So why should a customer buy a filter if he already knows that the water is safe to drink? The only way for a user to test the water in point of use today is with the TestDrop.
 
In many of your posts, you have expressed concern for the user who relies on our device, drinks and then dies.  We know that people have a serious concern regarding their water quality. The situation today is that they use water filters (which come with the above disclaimer) and other solutions with no information as to the actual water quality. How a user can know when should he replace the filter? The TestDrop is another tool in the arsenal to know if the tap water is safe to drink or if the filter should or shouldn’t be replaced.   

As you are all scientists and engineers, we believe that the best way to look at a new product is to test it rather than to just discuss it.  As such, we suggest that you consider purchasing your personal water tester at www.lishtot.com in order to test the device yourselves.  If you have additional questions, please avail yourself of the contact options on the website.
 

[AVGresponding]

As you are all scientists and engineers, we believe that the best way to look at a new product is to test it rather than to just discuss it.  As such, we suggest that you consider purchasing your personal water tester at www.lishtot.com in order to test the device yourselves.  If you have additional questions, please avail yourself of the contact options on the website.

Sorry, I recently spent all my money on some magic beans.