[HN Gopher] Focused Ultrasound
___________________________________________________________________
Focused Ultrasound
Author : birriel
Score : 121 points
Date : 2023-10-01 14:02 UTC (8 hours ago)
(HTM) web link (twitter.com)
(TXT) w3m dump (twitter.com)
| aaron695 wrote:
| The Tricorder moonshot was a stupid waste of time with their
| impossible stupid rules.
|
| A cheap conventual ultrasound in a stick would be a tricorder
| moment. Hook in a mobile phone and 3D analyzing humans or pets or
| livestock or many inanimate things becomes software.
|
| This is cool and all, but unless you get the tech out of their
| hands it'll go nowhere for decades. Just like we've stagnated
| with conventual ultra sound.
|
| The cost needs to be smashed down. It shouldn't take a moonshot.
| This is old tech that's not hugely complicated.
|
| Get these down to $50 - https://www.aliexpress.com/w/wholesale-
| ultrasound-transducer...
| mschuster91 wrote:
| > The cost needs to be smashed down. It shouldn't take a
| moonshot. This is old tech that's not hugely complicated.
|
| The tech is not the problem, the _certifications_ are. It 's
| incredibly expensive and onerous to bring new medical device
| designs to market, and for good reasons - if it were easier,
| you'd get _even more_ quackery than you already have now (e.g.
| homeopathy, penis enhancement pills, "nutritional"
| supplements).
|
| The same is true for airplanes. Your run-off-the-mill Cessna?
| Its design dates back to the 50s. Almost all of GA _still_ runs
| with fucking lead in the fuel because it took the FAA over 12
| years to get it certified, and even in the US it is estimated
| to take until 2026 (!) until G100UL is widely available. Europe
| doesn 't even have a timeframe.
|
| [1] https://en.wikipedia.org/wiki/Avgas#G100UL
| MauranKilom wrote:
| Not completely objecting to this idea, but even in ideal
| scenarios with high-tech hardware and specialized setup,
| getting useful US image quality can be non-trivial and requires
| training and expertise. I can conceivably see that these are to
| some extent technical limitations that can be overcome for some
| level of mass-adoption. However, I don't see what use cases you
| have in mind that don't require a doctor for interpretation
| anyway (in which case having a professional device and the
| required expertise present in the facility is much simpler and
| cheaper than putting it in the hands of every patient).
|
| But also, particularly for pets I believe anything with a non-
| negligible amount of fur or similar (i.e. anything that is not
| just bare skin) will be fundamentally impossible to achieve
| good enough acoustic coupling for. Unless you also sell shaving
| equipment with it. Anything with bone in the way (e.g. a
| ribcage with gaps smaller than a human one) is also more or
| less out.
|
| For inanimate objects I really wonder what use cases you have
| in mind. Acoustic properties (and coupling) are even more of a
| variable there...
| glfharris wrote:
| Describing it as a best kept secret seems unnecessarily
| adversarial. The medical community aren't jealously guarding
| treatments from the populace.
|
| Arguably shock wave lithotripsy, a common method for breaking up
| kidney stones, could be described as focused ultrasound.
| mmastrac wrote:
| I think it's a figure of speech meaning that it's just not
| widely known.
| jharohit wrote:
| Interesting - have a friend going through Prostate Cancer and all
| docs here in Singapore have suggested surgery + chemo. I noticed
| in Steve's shared PDF that Prostate Cancer has already crossed
| the FDA Approval and Reimbursement stage. Anyone had any personal
| experiences in using HIFU (high intensity focussed ultrasound)?
| Specifically the stage up to which it is effective over
| surgery+chemo
|
| My data sources: -
| https://cdn.fusfoundation.org/2023/02/06115144/Focused-Ultra... -
| https://www.mayoclinic.org/medical-professionals/urology/new...
| gadders wrote:
| You might find this podcast of interest. The guy talks about
| his experience of the TULSA procedure. They're kind of cynical
| about the state of prostate treatment in general but seem keen
| on this procedure.
|
| https://www.podchaser.com/podcasts/starting-strength-radio-9...
| _Microft wrote:
| Via Nitter:
|
| https://nitter.net/FutureJurvetson/status/170830632272960759...
| caycep wrote:
| From the brain side, those of us who remember the pallidotomy and
| thalamotomy days, the "noninvasive" part is a marketing misnomer.
| It's invasive (it's a lesioning/ablation therapy); it just
| doesn't require a pallidotomy. But it's a shockingly effective
| tactic; there's a steady stream of patients rolling in the office
| with mild symptoms who are willingly requesting to have a hole
| burned in their head.
|
| (Also it's turning out not to be nearly as effective in treating
| symptoms as deep brain stimulation)
| izoow wrote:
| I remember randomly visiting a lecture of one of my professors
| that specializes in high performance computing, he was showing
| off the research they do and it was regarding computing the
| necessary "parameters" for this. Apparently calculating the
| parameters for a single patient to focus just the right spot and
| not damage anything is a task that takes several hours on a
| supercomputer. This might've been like 5 years ago.
| gadders wrote:
| I recently learnt about this procedure for prostate cancer -
| TULSA (Transurethral Ultrasound Ablation)
|
| https://buschcenter.com/tulsa-procedure/
| elcritch wrote:
| NIH study:
| https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9579879/
| latchkey wrote:
| When I was a kid, I fell on my wrist. It healed up badly and
| formed a lot of calcium deposits around the bones. I couldn't
| bend my wrist backwards more than a couple degrees and it was
| painful. Went to a PT who used ultrasound treatments and
| stretching to break down the deposits, which freed my wrist up.
|
| This was in the 1980's.
| whatshisface wrote:
| Dealing acoustically with something different from the
| surrounding material (calcium deposits) is a lot easier than
| focusing on tissues with roughly the acoustic properties of
| water among other tissues with the acoustic properties of water
| - in the former case the stuff can distinguish itself w.r.t.
| application of the waves, the latter requires focusing to come
| "from the outside."
| minihat wrote:
| Not a secret to the research community... Let me balance the hype
| with some of the remaining challenges.
|
| Depth is a problem; the deeper you go, the less effective it is.
| Heat is another issue; you can inadvertently damage nearby
| tissue. Targeting accuracy is vital, especially near critical
| structures (think nerves), and we're not at sub-millimeter
| precision yet. Also, real-time monitoring like MRI-guided FUS is
| expensive and complicated, and without it you have to guess that
| you're affecting the right tissue. Great promise, but multiple
| engineering hurdles to clear before FUS lives up to the hype.
| denton-scratch wrote:
| > and we're not at sub-millimeter precision yet
|
| How do you get sub-millimeter precision with ultrasound? At
| 300KHz, the sound has a wavelength of 1mm. My understanding is
| that sound with a frequency greater than about 150Khz
| dissipates after passing through 5cms of _air_ ; it must
| dissipate faster in flesh.
|
| Also, a wavelength of 1mm should give you a resolution of about
| 4mm, right?
|
| I wish I knew more about the propagation of ultrasound; I'm
| getting interested in the bats that live around here.
| polishdude20 wrote:
| Isn't this like saying how can we move something one
| millimeter if our fingers are bigger than one millimeter?
| aesh2Xa1 wrote:
| Yes, I think it _is_ like saying that, but I also think
| that OP was considering targets less than 4mm in size. The
| focus of the FUS wave being no smaller than 4mm, very small
| targets would be larger than the smallest focus.
|
| It's like saying "how can a syringe extract the cytoplasm
| of a cell?" if you take OP's angle.
| polishdude20 wrote:
| Ah I guess in the case of ultrasound, the thing you're
| trying to do is not nudge or move something, you're
| literally trying to "ablate" or hit it and only it.
| That's more like pressing a tiny button with your finger
| and trying not to touch the outside of the button.
| IshKebab wrote:
| > My understanding is that sound with a frequency greater
| than about 150Khz dissipates after passing through 5cms of
| air; it must dissipate faster in flesh.
|
| Flesh is basically water. Water transmits sound extremely
| well.
|
| Ultrasonic imaging typically uses frequencies in the low MHz.
| Like 1-10 MHz.
| denton-scratch wrote:
| > Ultrasonic imaging typically uses frequencies in the low
| MHz. Like 1-10 MHz.
|
| Oh, thank you! So the dissipation is low (because it's
| water), and the theoretical resolution is 500x greater than
| my ignorant estimate. I now consider myself better-
| informed.
|
| [Edit] Now I guess I'm off to see if I can find out what a
| MHz-grade ultrasound transducer looks like...
| jameshart wrote:
| > At 300KHz, the sound has a wavelength of 1mm
|
| And that's in air. In water (which is more like what most
| bodily tissues are made of) the speed of sound is almost five
| times higher so the wavelength is five times longer.
| doh wrote:
| I know this is maybe completely out there, but could focused
| ultrasound be used to heat up food? The current issue with
| microwaves is that they heat up food very unevenly. I am sure
| the current cost is quite prohibitive and all. I'm more
| interested in the science part itself.
| Kirby64 wrote:
| Seems like the challenge would be heating the right places.
| How would you know what food to heat more or less?
|
| Also, ultrasonic transducers today, as far as I know, require
| essentially direct contact to impart energy. You probably
| don't want to dip something into your leftovers just to heat
| it.
| thrwyfrths wrote:
| I've always wondered what happened to Steve Jurvetson. He laid
| low for a while after resigning from the Tesla Board of
| Directors. I see he is active on Twitter/X now.
| cinntaile wrote:
| Isn't every VC investor basically a "thought leader" on
| Twitter? I assume it helps with deal flow?
| tommiegannert wrote:
| The gamma knife is a similar idea, but using gamma radiation
| focusing: https://www.mayoclinic.org/tests-procedures/brain-
| stereotact...
|
| Edit: similar _idea_
| bobim wrote:
| Meh? It's been on the French health market for at least two
| decades (Ablatherm).
|
| It's effective for people that wouldn't bear anesthesia but it
| comes with some limitations.
|
| It can't be used when there are bones, lungs or non-uniform
| propagation medium in front of the target. And while the tissues
| are burnt their mechanical properties are evolving and deflecting
| the beam. The cavitation due to negative alternance of pressure
| waves puts a limit on the power. Perfusion can take the heat
| away, etc...
|
| It's probably not widely used because conventional surgery is
| often more practical.
___________________________________________________________________
(page generated 2023-10-01 23:01 UTC)