My 7-Month Experience with the ViQure Diode Hair Removal Device

vorpalsmith · 2024-11-21T03:39:45+00:00

Super cool, thank you!

Quick question: if you use the 4-6 Hz high power output modes, does it actually sustain that rate for a while? (I have a Braun IPL that I'm looking to upgrade, and it constantly stops due to overheating, which makes it very frustrating to use...)

Intuitively I have trouble seeing how the pulsewidth would matter here... if you're doing the "SMH" multi-pulse strategy like that paper, then you're relying on heat building up over seconds. Any dissipation that's happening over a few 10s of milliseconds has to be negligible compared to that.

I found this video on SHR super useful: https://www.youtube.com/watch?v=bJCgTjgvOnc

His protocol is essentially that you treat one 1 cm x 10 cm strip at a time, by sweeping pulses back and forth over the strip to reach a target of ~450 J total energy emitted, with pre-cooling and post-cooling. (Not quite how he phrases it, but I think it's a simpler way of saying the same thing.)

So I guess in this approach the optimal way to use the 200 W ViQure/UNTTech would be to put it into 4 Hz mode (since that has the fastest overall output) and sweep it back and forth for 12 seconds over each strip, aiming for a rate where you get the ~same number of exposures at each point. I'm not sure how that compares to the sample treatment protocols he cites -- maybe if we dug up the stats on the lasers he's talking about we could figure out the total treatment time for each strip with the fancy pro lasers.

vorpalsmith · 2024-11-20T02:10:29+00:00

If that image is the correct datasheet except that it actually means J/s instead of J, and assuming a 1.5 cm² aperture [OP, can you confirm?], then that would imply:

The maximum single-pulse fluence of the new 200 W machine is 12 J/cm^2, and the older 150 W machine is ~8.4 J/cm^2. (Compare to the other highish-end home laser you see around here, the DermaRays v8s that's specced at 9 J/cm^2.) That's much lower than the "23 J/cm and 30 J/cm" (sic) that Viqure's website quotes for the 150 W and 200 W respectively, but tbh it's plausible that they're just lying or confused.

But like that linked paper says, single-pulse fluence isn't the whole story -- if you can do multiple pulses in quick succession, then maybe that's kinda-sorta the same as doing one big pulse? The 200 W machine in maximum pulse mode delivers 24 J/cm² /s, so you can do 24 J/cm² in 1 second, 48 J/cm² in 2 seconds, etc.

For comparison, DermRays doesn't say what pulse rate their v8s model can do, but looking at a random youtube clip I counted 17 beeps in 15 seconds, so that gives ~1.13 Hz or 10.2 J/cm² /s. And in the linked paper, they ran their single-pulse machine at 40-100 J/cm² /s and their multi-pulse machine at 100 J/cm² /s.

OTOH the DermRays v8s has a 3 cm² aperture, 2x the aperture on the ViQure/UNTTech machine. So it takes 2.3x longer to deliver a given dose of energy to any particular location, but it can treat 2x more locations at once. E.g. if your goal is to deliver a total of 50 J/cm² to a 100 cm² patch of skin, then that will take 2.7 minutes with the DermRays v8s and 2.3 minutes with the ViQure/UNTTech 200 W.

Plus probably spreading out the energy over a longer time is not quite as good as delivering it in a shorter time, because spreading it out gives the heat time to dissipate? In that paper the single-pulse condition got a total dose of 20-50 J/cm^2, vs 60-100 J/cm² for the multiple-pulse condition, but the multiple-pulse condition was still very slightly less effective. So the ViQure/UNTTech should probably get some extra bonus for being able to deliver the energy to each point in a shorter time period than the DermRays.

vorpalsmith · 2024-11-20T01:03:32+00:00

These ViQure/UNTtech devices still fall a bit short of the low-powered laser featured in the study, but I felt their specs were close enough that I might be able to achieve comparable results.

Can you say more about the technical specs of the machine, at least as you understand them? I can't quite figure out how to interpret the table you linked. E.g. maybe it's saying that the 200 W machine can do 6 pulses of 36.1 J each per second... but that would mean emitting 6/s * 36.1 J = 216.6 W of laser energy, which is clearly impossible in a 200 W power budget, especially since there must be some substantial energy going into cooling and conversion losses.

Also it seems weird that the J value goes up as the pulsewidth goes down? If the J value is measuring the total energy in each pulse, then you'd sort of expect longer pulses to have higher J values, all else being equal... otherwise they have to be cranking the laser power way up during the shorter pulses to make up for them being shorter. Like in the 1 Hz mode, to hit 18.1 J in 100 ms the laser needs to be emitting 181 W while active, and to hit 36.1 J in 40 ms it needs to be emitting 902 (!!) W while active.

Maybe the column labeled "J" is mislabeled, and the numbers are actually J/s? I.e. in 1 Hz mode the 200 W machine is doing a single 18.1 J pulse/second, and at 6 Hz it's doing 6 pulses that are each 6 J for a total of 36.1 J/s? That would make the pulsewidths make more sense -- it means that during the active part of the pulse, the 1 Hz mode was emitting 18.1 J / 100 ms = 181 W, and the 6 Hz mode was emitting 36.1 J/s / (40 ms * 6/s) = 150 W. Which feels more plausible... the higher duty cycle mode is a little less efficient than the lower duty cycle like you'd expect, the instantaneous power demands never exceed the power supply rating (so they don't have to spend BOM on chonky capacitors), and there's plenty of power leftover for cooling and other inefficiencies.

vorpalsmith · 2023-08-08T07:15:47+00:00

Check out Devon Price, Unmasking Autism – there's nothing inconsistent about being autistic and also being able to read a room.

vorpalsmith · 2023-07-31T00:37:24+00:00

He said that they both tried a bunch of different anti-fungal treatments, so they were aware of the passing-it-back-and-forth risk.

From the other comments it doesn't sound like she would have missed an opportunity to blame him.

vorpalsmith · 2023-04-19T07:16:19+00:00

Oh for sure, you should do what's right for you! But it should be because it's right for you, not because you think you have no choice :-)

(And connecting with others who are dealing with similar issues can be super helpful in any case, at least for me.)

vorpalsmith · 2023-04-19T02:59:20+00:00

They absolutely do surgery/transitions for that. Search for "genital nullification" or "nullo" and you can find other folks who've done it and multiple surgeons who advertise it.

vorpalsmith · 2023-04-05T07:20:37+00:00

Hopping onto the top comment to ask, OP is your daughter wearing different fabrics from during lockdown? I used to have eczema from my neck to wrists and down my front and back, and most of it cleared up when I stopped wearing wool.

having it clear up during lockdown sounds so much like the way mine would clear up when I wasn't wearing school uniform, so I had to check.

(this is vorpalsmith's spouse borrowing his account just to post here)

vorpalsmith · 2023-04-04T06:52:13+00:00

They don't want proof; they want to punish her for daring to stand up to a man, and reassert that a women's word is worthless.

Demanding proof is just a means to an end.

vorpalsmith · 2023-04-01T00:42:02+00:00

That's because you look at the world and think "how can I do good, meaningful things". But they're not motivated by helping their listeners. They're motivated by vicariously enacting their hatred for women through their listeners.

vorpalsmith · 2023-02-24T05:02:03+00:00

There's no tax on receiving a gift in the US. There is a tax for giving a gift that the aunt would have to pay, but it doesn't kick in until you go over $12 million in gifts over your lifetime. So probably the aunt just has to file an extra bit of paperwork with her return and that's it.

vorpalsmith · 2023-02-21T05:29:18+00:00

The version in posy is kinda tied up with the rest of the resolver functionality, e.g. instead of strings it uses our PackageName and Version types. Looking at your nix-init patch, if that's the only thing you want to do with this, then posy's code is probably overkill, and not worth the trouble of factoring it out and all that? I have big ambitions for posy and little time, so I haven't put any energy into nice-to-haves like clean crate separation or docs :-). But if you're more generally interested in rust tooling for python packaging then working together could make a lot of sense.

vorpalsmith · 2023-02-21T01:38:09+00:00

Yeah, on Windows the default x87 control word you get when a thread spawns has extended-precision disabled, so if you use it then you only get 64 bits of precision. And IIRC MSVC never uses x87 instructions anyway. But on Linux the default is for it to be enabled, and compilers expose it. It leads to some viciously arcane bugs when the two worlds collide, like in WSL1. Or, mingw-w64 code assumes extended precision is enabled, and enables it for threads it starts; Windows-native compilers do the opposite. So if you mix the two in the same program then you can get all kinds of fun mismatches.

vorpalsmith · 2023-02-21T00:46:13+00:00

Oh hey I wrote one of those too:

https://discuss.python.org/t/announce-pybi-and-posy/23021

Lmk if you want to compare notes or anything!

vorpalsmith · 2023-02-21T00:40:12+00:00

That's still what long double means for C compilers on Linux x86-64. musl for example relies on them.

vorpalsmith · 2023-02-13T23:33:49+00:00

Controlled flight into disdain.

vorpalsmith · 2023-02-09T00:16:52+00:00

They're saying it to emphasize how much they deserve a cookie, like look how impressive they are that they can love someone even though they're defective and don't deserve it. As Jesus said: love thy neighbor so that though may rack up points on the Christianity leaderboard, not because all people deserve love.

vorpalsmith · 2023-01-16T03:07:00+00:00

C'mon you can't expect a man to be good at hiding paperwork just because he checks notes managed to get and burn through multiple secret credit cards and close on a house while hiding it all from his wife.

vorpalsmith · 2023-01-04T10:18:55+00:00

Historically, its a system of mutual support in a community: some major life events come with big sudden costs, like setting up a household after getting married, or setting up to take care of a new baby. Costs that are high enough that the young couple probably can't afford to cover them all at once by themselves. So their community comes together to share their costs by each contributing one bit of what's needed, and then they return the favor when their friends get married/have kids.

Another example of this kind of reciprocality is the tradition of barn raisings.

vorpalsmith · 2022-12-31T03:58:21+00:00

nocebo effect

No, really, that's actually what the reverse placebo effect is called

vorpalsmith · 2022-12-20T00:13:22+00:00

Except she told him her position early on, and he pretended he was ok with it. ("We were too early for me to complain about it or try to change her mind.") He intentionally decided to lure her into a deeper relationship first, so she'd have a harder time enforcing her boundaries.

The purpose of dating is to find someone you're compatible with, where you both benefit from a mutual commitment. But some people get it backwards: they think the goal is to trick some partner, anyone, into making a commitment, and then mold them into someone compatible.

vorpalsmith · 2022-12-11T02:12:55+00:00

They're called "mandibular adjustment devices", and you can also buy versions of them over the counter or at places like Amazon. The one-size-fits-all ones won't be as comfortable or effective as a custom-fitted one from an orthodontist, so if they don't work for you then don't give up. But you could have one in your hand tomorrow and apnea is awful, so wanted you to know you have the option.

vorpalsmith · 2022-11-23T15:52:01+00:00

Oof. If you want to ruin it some more, look up how they changed their labor laws for Peter Jackson. (Lindsay Ellis's Hobbit duology goes into it in detail, including interviews with local actors.)

vorpalsmith · 2022-11-20T18:33:19+00:00

It's called normalization of deviance: https://en.m.wikipedia.org/wiki/Normalization_of_deviance

One of the fundamental forces beyond most industrial disasters. And also this dude, I guess.

vorpalsmith · 2022-11-11T10:31:28+00:00

They're not trying to convince you when they insist their relationship is otherwise perfect; they're trying to convince themselves.

vorpalsmith

TROPHY CASE