Speaker 1: Get in touch with technology with text stuff from how
Speaker 1: stuff works dot com. Hey there, everyone, and welcome to
Speaker 1: tex Stuff. I'm Jonathan Strickland, and I'm learning focal bind.
Speaker 1: Today we're going to talk about a technology that uses
Speaker 1: h uses sound really really super high pitch sound ultrasound
Speaker 1: in fact, yeah, which you know, first I thought was
Speaker 1: something that only transformers could make, as in the characters,
Speaker 1: not the actual devices that change voltages. And that's what
Speaker 1: I figured you meant. Okay, Well, I have to make
Speaker 1: sure you know I don't we do. We do try
Speaker 1: to be scientific here, yes, all right. So, as it
Speaker 1: turns out, humans have a certain range of sounds that
Speaker 1: a typical human can hear, keeping in mind that different
Speaker 1: people can hear different ranges. Some may be able to
Speaker 1: hear a larger range, some people like me are starting
Speaker 1: to lose some of that range, and some people are
Speaker 1: better at lower higher range. Is sure, um that the
Speaker 1: average is about twenty to twenty thousand hurts at the
Speaker 1: low and high end, right, So beyond twenty thousand hurts
Speaker 1: like usually significantly beyond twenty thousand hurts at those higher frequencies.
Speaker 1: We call that ultrasonic. Oh well, you don't quite get
Speaker 1: into ultrasonic um right away. I mean, I mean, you know,
Speaker 1: you've still got a good audible range. I mean like
Speaker 1: beluga whales, for example, can hear up to some like
Speaker 1: a hundred and twenty thousand hurts, but that is still
Speaker 1: not ultrasonic. Well, the true ultrasonic that we're looking at,
Speaker 1: for at least the the technology we'll be talking about
Speaker 1: today is in the one to one point five million
Speaker 1: hurts or mega hurts range. So that's where we're getting
Speaker 1: to a point where you know, animals are not detecting
Speaker 1: this kind of sound. It's not a pitch that's much
Speaker 1: higher than a frequency that's much higher frequency in pitch
Speaker 1: I'm I'm using almost interchangeably, which is a little this misleading,
Speaker 1: but you get what I'm saying. So this is a
Speaker 1: technology that's very much based in some part on something
Speaker 1: that actual animals are using. Some animals are using right
Speaker 1: eocation yep. And so that's something you probably heard about
Speaker 1: whenever you've you heard about things like bats or dolphins
Speaker 1: or whales, they all use echolocation as either a primary
Speaker 1: way of figuring out what their environments like in the
Speaker 1: case of bats, or you know, one of the many
Speaker 1: senses that they rely upon to explore their environments. Right.
Speaker 1: Humans also use this in the form of sonar or
Speaker 1: I mean really technically radar, because we're talking about electromagnetic
Speaker 1: waves and waves, so yeah, but some are specifically is
Speaker 1: so that is like a sonic wave. So uh. In fact,
Speaker 1: sonar was a very important development in our history because radar,
Speaker 1: as it turns out, was not the best thing to
Speaker 1: use for underwater because you have a tinuation of those
Speaker 1: waves and you could never be really sure that the
Speaker 1: signals you were getting back were really accurate. Sonar is
Speaker 1: a much more accurate means of determining where something is
Speaker 1: underwater and whether it's moving towards you moving away. We'll
Speaker 1: talk about more of that as we get further into
Speaker 1: this podcast, because some of those basic principles really determine
Speaker 1: some pretty cool uses of ultrasonic technology. Yeah, all of
Speaker 1: all of that history really builds upon the terrific baby
Speaker 1: viewing devices that we know and love today. Um, although
Speaker 1: that is certainly not the only use for ultrasound, as
Speaker 1: we will also get into. Yeah, I have a favorite
Speaker 1: one that I'll mention at the end. So, and it's
Speaker 1: one that I've talked about before on tech stuff. But
Speaker 1: that's okay. I don't mind repeating myself. All of you
Speaker 1: listeners out there who've been around for a while you
Speaker 1: know this, so I appreciate that you you humor me.
Speaker 1: I'm glad that you know this about yourself. John, Well,
Speaker 1: you know it's you reach a certain age, you come
Speaker 1: to some truths. So first, before I even dive into
Speaker 1: the history of ultrasonic technology, I have to give a
Speaker 1: shout out to Dr Jim Sung. He has a presentation
Speaker 1: online called the History of Ultrasound and Technological Advances that
Speaker 1: gave me a lot of insight into the the discoveries
Speaker 1: that lead to ultrasonic technol aology, and that's where I
Speaker 1: drew a lot of this information. So big to him,
Speaker 1: really really good, clear, yes, very very simple kind of presentation.
Speaker 1: I did, you know, augment that with extra research, but
Speaker 1: it was a great starting point. So in sevento that's
Speaker 1: where we have a fellow by the name of Lazaro
Speaker 1: Spaladzani who was observing the behavior of bats, and as
Speaker 1: he was observing their behavior, he began to hypothesize what
Speaker 1: it was that allowed bats to navigate through really dark terrain,
Speaker 1: being able to avoid things, be able to zero in
Speaker 1: on prey. And as he thought about it, he came
Speaker 1: up with this hypothesis that perhaps they were making these
Speaker 1: very high pitched noises that were not necessarily within the
Speaker 1: range of human hearing. You might be able to hear
Speaker 1: a few squeaks now and then, but that's about it,
Speaker 1: But that they were also uh, reacting to the echoes
Speaker 1: of those noises to hone in on things or to
Speaker 1: avoid obstacles, all right, to find about how far away
Speaker 1: or possibly even how big an obstacle or a predator
Speaker 1: or a piece of prey would be away from them. Yeah,
Speaker 1: because if if you're if you're hearing an echo come back,
Speaker 1: but it's not nearly as powerful as the sounds you
Speaker 1: put out your your the result might be, oh, that
Speaker 1: thing is close, but it's also small. If you get
Speaker 1: a lot of signal back, you're like, Okay, there's something
Speaker 1: with a lot of surface area that's not too far away,
Speaker 1: and perhaps I don't want to go in that direction anymore.
Speaker 1: So he kind of, you know, was the one to
Speaker 1: propose this hypothesis of echolocation. Now that's again one of
Speaker 1: those basic principles that we would build upon to get
Speaker 1: to ultrasonic technology. In eighteen twenty six, you have Jean
Speaker 1: Daniel Calladon who was performing a series of experiments using
Speaker 1: a bell like a church bell. It was actually a
Speaker 1: church bell that he put underwater. He had a another
Speaker 1: little lever that had a striker on the end of
Speaker 1: it to strike the bell. So if you like to
Speaker 1: imagine as one of those you remember then the cartoons,
Speaker 1: the boxing glove that's on the like accordion type thing
Speaker 1: stretches out. That's essentially what I imagined this to be.
Speaker 1: I'm sure that's exactly what it was not according to
Speaker 1: the illustration I saw, but those things are never accurate.
Speaker 1: So anyway, there's this bell that's underneath the water, and
Speaker 1: he has a striker under the water as well. And
Speaker 1: then about ten miles away, according to the illustration, there
Speaker 1: was a second person in a boat who had a
Speaker 1: tube that went down into the water and they would
Speaker 1: essentially put their ear to the tube to listen in
Speaker 1: like an ear earpiece and ear phone, yes, so that
Speaker 1: they could you would amplify any sounds they could maybe
Speaker 1: you know their and their job was to listen for
Speaker 1: the tone of the bell, and so uh, he would
Speaker 1: call it on strikes the bell, the person in the
Speaker 1: other boat writes down exactly when they heard the tone.
Speaker 1: And the idea here was actually for a call it
Speaker 1: on to show that the sound would travel at a
Speaker 1: different speed through water that it did through the air.
Speaker 1: This was us to demonstrate hypothesis that sound traveled at
Speaker 1: different speeds through different media, something that we know to
Speaker 1: be true now, right, And and in fact, it travels
Speaker 1: faster in water than it does the air. Yeah, So
Speaker 1: depending upon it how tightly packed the molecules are and
Speaker 1: whatever it is that you're looking at, sound can travel
Speaker 1: much more quickly through some media than others. And it's
Speaker 1: because it's a very it's a physical media. It's not
Speaker 1: an electromagnetic it's actual physical molecules banging into each other.
Speaker 1: So if they're more tightly packed, they banging into each
Speaker 1: other much more quickly. So in that case he was
Speaker 1: able to show that it indeed does travel at different speeds.
Speaker 1: Knowing that it travels at different speeds is also very
Speaker 1: important for the very basics of ultrasonic technology, which is
Speaker 1: why we're talking about in the first place. So eighty six,
Speaker 1: our next date is eighteen eighty we're just just scorching along.
Speaker 1: This is where Pierre and Jacques Curie discover the piece
Speaker 1: of electric effect, which we have talked about quite a
Speaker 1: few times on tech stuff. All Right, this is this
Speaker 1: winds up being useful in many applications. But so what
Speaker 1: is it? Okay? So certain types of material, like for example,
Speaker 1: quartz crystals have this this particular this particular feature where
Speaker 1: if you were to apply an electric charge to this material,
Speaker 1: it would vibrate, or if you apply a mechanical stress
Speaker 1: to this object, it will then create an electrical charge.
Speaker 1: It's this weird reaction of electricity and actual kinetic movement
Speaker 1: energy that you're gonna see between the two things. And
Speaker 1: in the case of quartz crystals, it's really really regular.
Speaker 1: You know, if you know the properties of the quartz crystal,
Speaker 1: you are good to go. You know that at a
Speaker 1: certain charge, it's always going to give off the same
Speaker 1: kind of vibration. So that's why quartz crystals are used
Speaker 1: in a lot of watches. It's actually the thing that
Speaker 1: helps keep time right right. It creates the movement in
Speaker 1: courts watches because it is so regular or so so predictable.
Speaker 1: Um it also can it's used to create a spark
Speaker 1: in the kind of gas lighters that are used for
Speaker 1: for candles or cigarettes. And also um, you know, it's
Speaker 1: being talked about for energy harvesting kind of materials that
Speaker 1: are being that are in research today right and now.
Speaker 1: In the case of ultrasonic technology, this is important because
Speaker 1: the quartz crystals are the things in most ultrasonic transducers
Speaker 1: that are creating the vibrations that themselves are these high
Speaker 1: frequency sound waves. And with something as simple as electricity
Speaker 1: or relatively simple or you know, relatively technologically um possible
Speaker 1: to put into an instrument. So also they're very important
Speaker 1: for picking the signals back up as its out. Well
Speaker 1: we'll talk more about that when we get into the
Speaker 1: actual how it works stuff, but all of this, you know,
Speaker 1: again plays into it. So nineteen fifteen you have Paul
Speaker 1: Langevin who invents the hydrophone, which again very important this
Speaker 1: in this case it's essentially a microphone that can go
Speaker 1: into the water, uh and it relies on the piece
Speaker 1: of electric fact in order to pick up signals in
Speaker 1: the water. What it's doing is it's detecting changes in pressure,
Speaker 1: which are you know, that's what you know, the sound
Speaker 1: that's moving through the water is changing the actual pressure
Speaker 1: that the this hydrophone detects. The pressure changes affect the
Speaker 1: quartz crystals inside the hydrophone, which then generates the electricity,
Speaker 1: which then goes to another device that again in turns
Speaker 1: and figure out yeah, or even convert it back over
Speaker 1: into sound so that you can listen to what's going
Speaker 1: on underneath. He got the the inspiration to really work
Speaker 1: on this after something that happened in nineteen twelve, which
Speaker 1: was when Leonardo DiCaprio sank to the bomb of the
Speaker 1: ocean and froze to death, or more historically speaking, is
Speaker 1: when the Titanic sank. I thought what I just said, Well, um,
Speaker 1: but yeah, yeah. The hydrophone was originally created in order
Speaker 1: to help detect icebergs and submarines and large World War
Speaker 1: One and World War Two. It was really important. World
Speaker 1: War two is also really when sonar I came into play.
Speaker 1: But before sonar it was really just listening or stuff
Speaker 1: that you think that should not be there and we
Speaker 1: need to get out of here. So ninety seven or
Speaker 1: right thereabouts, a man named Carl Dissick, who was a
Speaker 1: doctor with the University of Vienna, begins to work on
Speaker 1: using ultrasound as a means of diagnosing brain tumors. Now,
Speaker 1: at this time ultrasonic technology was mostly being used in
Speaker 1: those those non applications exactly. But he thought, you know,
Speaker 1: this could probably tell you more about what's going on
Speaker 1: inside a person. Human brain is filled with water. Yeah,
Speaker 1: I can, I mean essentially, yeah, I can totally figure
Speaker 1: out what's going on. Maybe if there's a tumor or something,
Speaker 1: I can detect it. Now, his approach is very different
Speaker 1: from what is used today. What we use today is
Speaker 1: a reflective technique where you send a signal through a person.
Speaker 1: It reflects off of various various stuff we'll go into
Speaker 1: more detail in the second half and bounces back and
Speaker 1: then by a receiver in the instrument right exactly, and
Speaker 1: in a computer kind of puts all that data together
Speaker 1: to make it meaningful to you. He was actually thinking
Speaker 1: about setting up two different ultrasonic transducers, one on either
Speaker 1: side of your noggeting and zapping straight through the brain.
Speaker 1: So he had a receiver on both sides and a
Speaker 1: transceiver on both sides, so you're sending signals simultaneously. And
Speaker 1: the idea was that he he thought that the reflection
Speaker 1: would never be reliable enough for you to be able
Speaker 1: to have any sort of precise idea what's going on.
Speaker 1: Other people said that his particular techniques were um muddy,
Speaker 1: like it was creating too much noise because you had
Speaker 1: these two different sources going at it, and so right right,
Speaker 1: some of it's reflected back, some of it keeps going through,
Speaker 1: and so there are people who said that the information
Speaker 1: you would get back from this particular method UH was
Speaker 1: you know, not terribly reliable. Dest because it turns out
Speaker 1: would go on to UH be drafted into the Luftwaffe
Speaker 1: during World War Two and actually would become a doctor
Speaker 1: treating head wounds for German soldiers. UM. He would continue
Speaker 1: after the war to really be a proponent of ultrasonic
Speaker 1: technology being used in the medical field. However, he continued
Speaker 1: to say that he wanted the transmission effect was more
Speaker 1: important than the reflective effect UH And ultimately some researchers
Speaker 1: at M I T determined that the method that Dosik
Speaker 1: was using was creating all this noise I was talking
Speaker 1: about before, and it really wasn't reliable. So history would
Speaker 1: end up switching gears, going the different direction and still
Speaker 1: using ultrasonic technology. But in a different implementation than he did. Yeah,
Speaker 1: and and absolutely that pioneering kind of going like, hey,
Speaker 1: human bodies are fill of liquid. We can use this
Speaker 1: technology to look at them too. Yeah, it's pretty. It's sound.
Speaker 1: It's not like it's ionizing radiation. It's not something that's
Speaker 1: gonna cause you some form of harm. It's it's a
Speaker 1: physical that There are a couple of concerns that I've
Speaker 1: heard here and there about the ultrasonic waves interfere ing
Speaker 1: or or creating small bubbles or or various things like right, right,
Speaker 1: But it's not an ionizing radiation, which is the main
Speaker 1: difference between that and other imaging. Definitely better than X rays. Yes,
Speaker 1: uh so that's when Dr George Ludvig writes a paper
Speaker 1: describing the use of an ultrasonic device to diagnose skull stones,
Speaker 1: and in nineteen fifty one, doctors Wild and Neil began
Speaker 1: publishing studies on ultrasonic characteristics of benign versus malignants, not
Speaker 1: intended as a detection tool actually, but rather as a
Speaker 1: diagnostic tool once a tumor had been found, so, in
Speaker 1: other words, to determine whether or not this tumor effect
Speaker 1: is benign or malignant. So yeah, so this is after
Speaker 1: we've already established it there is a presence of a tumor.
Speaker 1: Ninety eight we got Dr Ian Donald, who I love
Speaker 1: his technical title, which was Professor of Midwifery at the
Speaker 1: University of Glasgow. Yeah, he pioneered O B G Y
Speaker 1: and ultrasound, which is what most of us think about
Speaker 1: when we think of ultrasound devices in medical fields. I
Speaker 1: think it's it's I think for the common lay person,
Speaker 1: that is the application in which we have seen and
Speaker 1: heard it used. Yeah, and it's it's certainly one that
Speaker 1: oh no, that was kind of a sorry, didn't do
Speaker 1: it this time. So it's it's certainly the thing that
Speaker 1: we see all the time in movies and television, and
Speaker 1: you know, it's the sty it's that's the typical couple
Speaker 1: is in the hospital. This is the picture of the baby.
Speaker 1: It's also I mean I just recently saw one because
Speaker 1: my sisters have. Yeah, a lot of people are born,
Speaker 1: it turns out, Yeah, and it's a very popular way
Speaker 1: of of imaging before. I mean, you know, especially and
Speaker 1: we'll we'll go into this a little bit more later,
Speaker 1: but you know, it's it's really terrific for figuring out
Speaker 1: what's going on with a baby without doing any kind
Speaker 1: of harm to the mother or the baby. Right right,
Speaker 1: You don't want anything that could potentially disrupt development or
Speaker 1: cause other complications. Uh So, skipping way ahead, because obviously
Speaker 1: ultrasound by this time had been an established medical technology.
Speaker 1: It also was used in other applications. Will talk a
Speaker 1: little bit about that later. Uh, skipping way ahead, we
Speaker 1: get to a point where Daniel Lichtenstein pioneers a point
Speaker 1: of care long ultrasound in the I c U and
Speaker 1: says that ultrasound is the real step the scope. At
Speaker 1: this stage, we're talking about precision where uh, it was
Speaker 1: much greater than anything that desn'k ever managed. It was
Speaker 1: something where you could actually get a really accurate look
Speaker 1: and in some cases a three dimensional look at what's
Speaker 1: going on inside a person without it being invasive or
Speaker 1: terribly invasive. Because there are some there are some exceptions
Speaker 1: we'll talk about, yes, but but this is mostly thanks
Speaker 1: to advancements in computers and the digitization of ultrasound exactly.
Speaker 1: So we're gonna talk a lot more about how this
Speaker 1: actually works, what's really going on with this stuff. But
Speaker 1: before we get into that, let's take a quick break
Speaker 1: to thank our sponsor. Alright, so we're back. Let's talk
Speaker 1: about how ultrasonic technology actually works. You have to be
Speaker 1: able to have something that creates an ultrasonic signal, and
Speaker 1: it has to be able to pick up that ultrasonic signal,
Speaker 1: and then it has to be able to interpret that signal.
Speaker 1: So these are these are some important elements that again
Speaker 1: would only have been possible due to the work of
Speaker 1: the people we talked about in the first half. So, uh,
Speaker 1: your basic your basic approach here. This is before I
Speaker 1: get into any of the actual Here's the technical stuff
Speaker 1: that's going on. Is you've got a device that sends
Speaker 1: the signal out which then encounters the various tissue barriers
Speaker 1: in a person's body for ultrasonic medical imaging anyway. So, uh,
Speaker 1: as it encounters these barriers, some of those ultrasonic waves
Speaker 1: are gonna bounce back. So the machine starts to collect
Speaker 1: the data of the material of the waves that bounce back,
Speaker 1: the intensity of those waves, and the length of time
Speaker 1: it took for them to go out and bounce back,
Speaker 1: give the idea of things like the depth and the
Speaker 1: nature of the tissue itself. The uh, some of the
Speaker 1: waves will continue to penetrate into the patient's body and
Speaker 1: then bounce off other boundaries. So these boundaries are things
Speaker 1: like boundaries between liquids and soft tissue, or soft tissue
Speaker 1: and hard tissue, so and oregon and bones, that kind
Speaker 1: of thing. And as the waves go and bounce back,
Speaker 1: we start to be able to look at that data
Speaker 1: and determine what kind of tissue it was going through,
Speaker 1: because because we know that that these sound waves travel
Speaker 1: at different speeds through different types of Yeah, exactly, so
Speaker 1: by knowing, you know, if you know that sound travels
Speaker 1: at such and such a speed as it goes through bone,
Speaker 1: which we do know, I mean I don't know it.
Speaker 1: I don't We don't personally know. But human kind knows.
Speaker 1: People smarter than you know. You have that thing where
Speaker 1: you just trust that people smarter than you are working
Speaker 1: on the problem. In this case, it's true, so not
Speaker 1: so much working as much as have already completely figured out.
Speaker 1: There are charts that you can look at. So the computer,
Speaker 1: which we'll talk about in a second, takes all this
Speaker 1: data in and is able to analyze it and determine
Speaker 1: which waves were the ones that passed through liquid, which
Speaker 1: ones were the ones that passed through soft tissue, which
Speaker 1: ones passed through hard tissue, and then adding all that
Speaker 1: information together is able to create a picture that's then
Speaker 1: displayed on a display. It sends the information to it
Speaker 1: to place that you get essentially a virtual representation of
Speaker 1: whatever it is that's there. Typically it's two dimensional, so
Speaker 1: we'll talk a bit about three D. Uh ultra relatively
Speaker 1: new development, but it is certainly possible. But your traditional
Speaker 1: ultrasonic images are two dimensional. So it's kind of like
Speaker 1: a a side view or top down view, depending upon
Speaker 1: the angle that's being used and what you are specifically
Speaker 1: trying to image, right, So, uh, it's a really cool approach. Now,
Speaker 1: the parts that are on an ultrasonic machine include the
Speaker 1: transducer probra, which we've talked a little bit about. Right.
Speaker 1: This is the device that is sending and receiving the signals. Yep,
Speaker 1: that's got at least one quartz crystal in it. It
Speaker 1: may have multiple quartz crystals in it, and in fact,
Speaker 1: if it does have multiple quarts crystals, you can time
Speaker 1: the different crystals to fire at different you know, you
Speaker 1: send charges to them at different times because each one
Speaker 1: has its own independent circuit. And that allows you to
Speaker 1: quote unquote steer the trasonic beam and be able to
Speaker 1: get a lot more precision about what's going on. Um
Speaker 1: But even if it only has one crystal, I can
Speaker 1: still send and then receive. So what's happening is you
Speaker 1: send an electrical charge to the crystal. The crystal vibrates
Speaker 1: at this incredibly high frequency, which creates this ultrasonic sound
Speaker 1: like one to one point five megahurts, And you're talking
Speaker 1: about possibly millions of these in a millions of pulses
Speaker 1: in a single second. They go into the body and
Speaker 1: start to bounce off of stuff. When the sounds bounce
Speaker 1: back to the transducer probe, they hit the Courts crystal,
Speaker 1: which causes the quartz crystal to vibrate, which then causes
Speaker 1: the electric charge to emanate. So because of that piece
Speaker 1: of electric effect, it works both ways. The device picks
Speaker 1: up the electric charges and that's what it's able to
Speaker 1: use to interpret the actual data that is gathered and
Speaker 1: sent onto the computer. So the computer, it's a CPU
Speaker 1: is you know, it's a computer. It it processes data,
Speaker 1: crunches numbers, It follows specific rules that have been programmed
Speaker 1: in that take into account all the basic information that
Speaker 1: we understand about how sound travels. So that's how it's
Speaker 1: able to build the actual useful information and generates this
Speaker 1: image on the screen. Right. Then you also have controls,
Speaker 1: big surprise there, right, So the controls allow you to
Speaker 1: do things like you have a medical practitioner who's called
Speaker 1: an ultrasonographer. Um, so the ultrasonographer can adjust things like
Speaker 1: the amplitude of the ultrasonic waves, their frequency, the duration
Speaker 1: of the pulses that the transducer probe is creating. All right.
Speaker 1: That the precise frequency of the waves greatly affects the
Speaker 1: resolution of the resulting image. So this is really important, yes,
Speaker 1: it really is. It also will determine how far the
Speaker 1: pulses can penetrate. And on top of all those other things,
Speaker 1: you also have a storage medium of some sort you
Speaker 1: want to save this data. Obviously that might be on
Speaker 1: a disk, or it might be on a you know,
Speaker 1: just a hard drive or whatever, but it has to
Speaker 1: have some source storage medium and also probably straight to
Speaker 1: the cloud to the cloud, which is possible now, and
Speaker 1: also a printer so that you can print out an image,
Speaker 1: especially in the case of babies. I think that it's
Speaker 1: it's used more often in that case than um, yeah,
Speaker 1: than than necessarily like, here's how your heart isn't working that.
Speaker 1: I mean maybe if you want to collect that sort
Speaker 1: of thing, maybe you do. I'm not judging, but no,
Speaker 1: that's exactly My sister showed me a picture from her ultrasound,
Speaker 1: so I got to see my niece or nephew early.
Speaker 1: So that's kind of cool. Um And now you know
Speaker 1: the that's that's your basic parts of the ultrasonic device.
Speaker 1: Keeping in mind that other you know, more advanced ones
Speaker 1: may have other elements to them, but that's that's what
Speaker 1: is kind of the bare requirements for you to have
Speaker 1: an ultrasonic medical device. So the only other thing I
Speaker 1: need to mention is that those those transducer probes also
Speaker 1: tend to have some sort of absorbent material that will
Speaker 1: allow it to absorb any uh echoes that would come
Speaker 1: from the probe itself, because otherwise you would gets right, So,
Speaker 1: because you don't want the crystal to just start vibrating
Speaker 1: as soon as something bounces off the interior of the
Speaker 1: probe and comes right back at the crystal. So that's
Speaker 1: what the absorbent materials for it's designed. So that it'll
Speaker 1: try and direct. There's actually an acoustic lens that directs
Speaker 1: the sound towards the patient's body. So that's the basics.
Speaker 1: But you know that we mentioned already there's a little
Speaker 1: bit more than just the basic display and imaging. There's
Speaker 1: this whole three dimensional approach UM, so first of all,
Speaker 1: to get the unpleasant parts out. Not all ultrasound is noninvasive, right, UM,
Speaker 1: it's not always external that there is recent controversy about
Speaker 1: this UM in in abortion law. Oh I did not
Speaker 1: know this, right, Well, it's it's the trans translational ultrasound
Speaker 1: in contests. So yeah, because because sometimes UM, for for
Speaker 1: for many applications, you're looking at something in the body
Speaker 1: that is not the most easily accessed from the outside.
Speaker 1: So by by inserting a probe with an ultrasound uh
Speaker 1: bit on the end into an orifice of one kind
Speaker 1: or another, UM, you can determine many things about many
Speaker 1: important internal organs. Yep. So this is uh. You know,
Speaker 1: it's probably a little less glamorous and comfortable than your
Speaker 1: typical ultrasound, but it's very important and it's still in
Speaker 1: the grand scheme of things. Like you know, it's hard
Speaker 1: to say it's non invasive because you're talking about inserting
Speaker 1: something into an orifice. But yeah, exploratory surgery way more invasive,
Speaker 1: So it's you know, it's either way. There's some approaches
Speaker 1: now where you can actually create three dimensional images of
Speaker 1: stuff using ultrasound, and it's pretty much what you would expect.
Speaker 1: You're you're you're moving the uh, the device, the transducer probe,
Speaker 1: whether it's internal or external, and you're trying to get
Speaker 1: multiple different views of whatever it is you're imaging. So
Speaker 1: in the case of a baby, it would be the
Speaker 1: baby and all you might have to have the patient
Speaker 1: shift around or in order to get angles. But yeah,
Speaker 1: the computer takes in all that data and then creates
Speaker 1: a three dimensional model of whatever it is it's that
Speaker 1: it's encountered, and then you can look at that on
Speaker 1: the screen. So this could be used in all sorts
Speaker 1: of medical approaches. And uh. One of the things that
Speaker 1: relies upon is another basic physical property that are sound waves,
Speaker 1: and that we talked about before. Actually it's of any
Speaker 1: real waves, the Doppler effect, right, the and that's the
Speaker 1: thing that that describes how waves change shape when they
Speaker 1: encounter moving objects. Yeah, so whether you whether the observer
Speaker 1: is moving or something is moving toward an observer. This
Speaker 1: affects the way sound sounds to us. This is the
Speaker 1: way we perceive sound. It also affects the waves themselves.
Speaker 1: So let's say that uh, that Lauren is uh is
Speaker 1: screaming at a a single tone, constant pitch, perfect pitch.
Speaker 1: But she is just screaming, and I'm running towards, which
Speaker 1: is probably what's causing the screaming. To me, the pitch
Speaker 1: is going to sound higher in nature than someone who's
Speaker 1: standing right next to Lauren wondering why she's screaming. And
Speaker 1: for the person who's running away from Lauren, because that
Speaker 1: person knows when Lauren screams, that's bad news. It sounds
Speaker 1: like it's a lower pitch. Now. That's because as I'm
Speaker 1: running towards Lauren, those waves, the sun waves coming toward me,
Speaker 1: are actually compressed, right uh, huh and uh. And as
Speaker 1: you would run away from a noise, the sound waves
Speaker 1: lengthen and therefore deepen in pitch. Yeah, So this Doppler effect.
Speaker 1: If you know what the Duppler effect is, and you're
Speaker 1: able to measure it properly, you can actually use that
Speaker 1: to your advantage. To determine the location of a moving object,
Speaker 1: whether it's moving towards you or away. In this case,
Speaker 1: it's being used to help create that three dimensional model.
Speaker 1: At any rate, this method, the Doppler effect method, is
Speaker 1: mainly used for very specific types of imaging. Not all
Speaker 1: three D imaging is using this. Mostly it's stuff where
Speaker 1: you want to measure something really subtle, like blood flow
Speaker 1: through veins right in. In In early experiments with this,
Speaker 1: an intravenous contrast agent would be introduced um but then
Speaker 1: as the method was honed, we've we've become able to
Speaker 1: detect movement of the blood cells themselves via change in pitch.
Speaker 1: That's pretty amazing and it's really useful. I mean it's
Speaker 1: for diseases that are largely invisible to us, right, oh right, right,
Speaker 1: anything vascular, you know, finding clocks or monitoring flow and
Speaker 1: risky patients you know, like like after a stroke or
Speaker 1: transplanter surgery, um, as well as finding cancerous tumors based
Speaker 1: on on the way that the blood flow is being
Speaker 1: affected by the tumor. It's pretty phenomenal. I mean, I
Speaker 1: really find this stuff truly amazing. So it really became
Speaker 1: possible only with the digital Revolution of the nineteen eighties,
Speaker 1: like we were saying earlier, because you know, computers made
Speaker 1: it possible to to aim more precisely shape that ultrasonic
Speaker 1: beam as we as we mentioned, and and be two
Speaker 1: to use multiple beams from multiple angles simultaneously, which is
Speaker 1: that that multi courts action that we were talking about.
Speaker 1: And you're talking about an enormous amount of debt, So
Speaker 1: it has to be a powerful computer just to crunch
Speaker 1: all the numbers properly. So as as those technologies have improved,
Speaker 1: so have the techniques. So let's talk a little bit
Speaker 1: about what it would be like to go in and
Speaker 1: have to have an ultrasound procedure done. Because a lot
Speaker 1: of people I think I've only seen this on television
Speaker 1: shows or movies. Yeah, um I I if this isn't complete,
Speaker 1: t M I UM, I have actually had an ultrasound done.
Speaker 1: Um I. I go in for a mammogram every year,
Speaker 1: and in addition to the mammogram, they also do an ultrasound.
Speaker 1: All right, So so tell me if I got any
Speaker 1: of this wrong, because I have not got in for
Speaker 1: an ultrasound so I. But I based it off a
Speaker 1: great article called how Ultrasound Works from how stuff works
Speaker 1: dot com plug. So, uh, typically what you have as
Speaker 1: a patient comes in and removes his or her clothing
Speaker 1: or whatever clothing would be in the way specifically of
Speaker 1: the ultrasound equipment. Sure, because you don't want to pick
Speaker 1: up the cloth. That wouldn't be useful, right, That would
Speaker 1: that would be that would corrupt the signal, So you
Speaker 1: would be that would make things more difficult. Also, it
Speaker 1: could end up just even if it didn't directly interrupt
Speaker 1: the signal, it could cause the probe to not be
Speaker 1: flush flush against the skin, which could cause problems right
Speaker 1: along those lines. Yeah, so we're getting into the jelly,
Speaker 1: aren't we, the mineral oil based jelly. You might wonder
Speaker 1: if you've ever seen essentially Yeah, but but if you've
Speaker 1: ever seen any other movies where they they're spreading the
Speaker 1: jelly over a patient's skin before using the ultrasound, you're
Speaker 1: wondering why it's so that they can seal up any
Speaker 1: air pockets that would have formed between the transducer probe
Speaker 1: and the skin of the patient. Right, Because, like we've
Speaker 1: said before, since sound waves move differently through different media,
Speaker 1: when you've got air in the way, that's going to
Speaker 1: cause some problems, right, so you don't want any air
Speaker 1: in the way. That's why the jelly is used. So
Speaker 1: in case you were ever wondering, that's the purpose. Now
Speaker 1: at that point you have the machine sending through those
Speaker 1: ultrasonic signals through the patient and picking up the result
Speaker 1: through the probe through the patient exactly, and then those
Speaker 1: sounds reflecting off of the various tissues within the patient
Speaker 1: coming back through the probe, sending those signals back to
Speaker 1: the CPU, which then interprets them and sends the signals
Speaker 1: to display which may or may not be in view
Speaker 1: of the patient, depending upon what the procedure is and
Speaker 1: depending on you know, whether the patient is is conscious
Speaker 1: or whether they want to be looking at it um,
Speaker 1: and that the tech could at that point mark areas
Speaker 1: for further investigation UM if needed. Yep, and then that's uh.
Speaker 1: Information is usually recorded onto the storage media so that
Speaker 1: it can be part of the patient's record. And uh,
Speaker 1: then that's the patient is pretty much allowed to Uh, well,
Speaker 1: they're they're cleaned up the jelly. Yes, yes, they give
Speaker 1: you a towel so you clean yourself up and then
Speaker 1: you put your clothes on, and that part of the
Speaker 1: examination is done so it's pretty simple in the grand
Speaker 1: scheme of things. It's like it's like we said, your
Speaker 1: basic ultrasonic uh investigation there is non invasive, so that's
Speaker 1: a good thing. UM. Now, beyond the diagnoses, they're actually
Speaker 1: looking at using ultrasonic technology to do some treatments. So
Speaker 1: it's not just a a tool that's used to check
Speaker 1: up on someone or get another look at something that
Speaker 1: may or may not be a problem. In some cases,
Speaker 1: they're talking about using it to to treat medical conditions,
Speaker 1: often with nanotechnology. Although one of the coolest ones I
Speaker 1: read about recently is another diagnostic tool, not a medical
Speaker 1: treatment tool. It's a nano device that's an a nano
Speaker 1: sized ultrasonic transducer that can actually image the interior of
Speaker 1: a cell individual living cell. That's awesome. Yeah, it's pretty
Speaker 1: neat when you can get that precise, that's pretty phenomenal. Uh. Yeah.
Speaker 1: We we talked in a previous episode are are one
Speaker 1: about gene therapy from December a little bit about one
Speaker 1: of the other applications UM, which is using using ultrasound
Speaker 1: waves to UM to push a little kind of nano
Speaker 1: bubbles of of either medication or or genes or whatever.
Speaker 1: You want to get inside a cell over to to
Speaker 1: where you want them, and then also using that ultrasound
Speaker 1: wave to burst them appropriate. So that becomes a method
Speaker 1: of delivery where you're actually maneuvering medication to some specific location,
Speaker 1: which that that's seems to be the big approach right now,
Speaker 1: using ultrasonic or other technologies that are externally applied to
Speaker 1: get nano based medicines to the right location, because we
Speaker 1: haven't reached a point yet where we have little like
Speaker 1: nano sized spaceships that can go straight to where they
Speaker 1: need to go and then deliver the medical payload. So
Speaker 1: a lot of the actual controls are not you know,
Speaker 1: because we've talked about nano robots before. This idea of
Speaker 1: a autonomous or even semi just semi autonomous machine that
Speaker 1: can move through the body. We are not there yet.
Speaker 1: But what we can do is create nano sized particles
Speaker 1: that can be manipulated externally through things like ultrasonic frequencies,
Speaker 1: which is kind of cool and you know, speaking of
Speaker 1: using ultrasonic technology in fun ways, here's a fun way
Speaker 1: the ultrasonic technology is to be used. So back in
Speaker 1: the seventies, Lauren, there used to be an era called
Speaker 1: the nineteen seventies. I do not remember that era because
Speaker 1: I was not born yet. I was alive during this era.
Speaker 1: So uh in the early nineteen seventies, a lot of
Speaker 1: televisions that were coming out that had remote controls. Often
Speaker 1: not always, but often would use ultrasonic frequencies to be
Speaker 1: the signals that would send it to the television so
Speaker 1: that you could turn it on or off, or the
Speaker 1: volume or change channel or whatever. Uh So you would
Speaker 1: push a button and often it was just on or
Speaker 1: off like that was sometimes the only control that you had.
Speaker 1: Oh sure, I mean we we didn't have channels in
Speaker 1: those days anyways. Usually it is usually about you know,
Speaker 1: between you'd have the channels two through thirteen in the
Speaker 1: new UHF channel. Anyway, you could turn the set on
Speaker 1: or off using this device and it would send us
Speaker 1: ultrasonic frequency that you could not hear, but it would
Speaker 1: be picked up by the television and it would do
Speaker 1: whatever it was supposed to do. The fun thing was
Speaker 1: that you could actually trigger this accidentally if you were
Speaker 1: messing around with something else, like I had uh an
Speaker 1: uncle who talked about how um he thought it was
Speaker 1: amazing when he accidentally turned off the television because he
Speaker 1: was carrying um a a like a container of nuts
Speaker 1: and bolts. He was going to do a project, and
Speaker 1: he tripped and dropped them and they hit the tiled
Speaker 1: floor and they and some of them must have created
Speaker 1: this ultrasonic frequency that was the exact same frequency that
Speaker 1: telled the TV to turn off. And so he was
Speaker 1: wondering what was wrong with his television. And it wasn't
Speaker 1: until you know, some further experimentation that he figured out, Oh,
Speaker 1: so sound, Chris Pallette, the he used to change the
Speaker 1: channel or turn this television off by playing with a slinky.
Speaker 1: So um yeah, fun times. Now these days, kids, uh,
Speaker 1: they're using either infrared or WiFi signals or some crazy
Speaker 1: thing like that. So you can play with a slinky
Speaker 1: all day along in front of your television and nothing's
Speaker 1: gonna happen unless you happen to have a or a
Speaker 1: mischievous sibling with a remote control who was like, wow,
Speaker 1: look at what you're doing, which could either be funny
Speaker 1: or you know, build you up for a terrible letdown later.
Speaker 1: Ultrasound can also be used to keep your car windshield clean.
Speaker 1: Say what seriously, the vibrations bounce rain to breathe like
Speaker 1: bugs whatever, right off of your of your windshield. Um,
Speaker 1: there's a high end British car company called McLaren that
Speaker 1: is looking to bring this tech to consumer cars. Um,
Speaker 1: assuming that your consumer with you know, over two hundred
Speaker 1: thousand dollars to drop on a car. So Elon Musk
Speaker 1: will obviously be getting one of these, yes, and by
Speaker 1: putting that on this submarine car, which will be amazing
Speaker 1: because the submarine car will go underwater but no water
Speaker 1: will touch the windshield. It's it's already in use in
Speaker 1: some like like high end racing vehicles and stuff like that.
Speaker 1: I'm curious to see that in action. Not curious enough
Speaker 1: to start saving up two for a car I'll never drive,
Speaker 1: but I am curious about it, all right. Well, so
Speaker 1: that's that's kind of our overview of ultrasonic technology specifically
Speaker 1: in the medical field. Like we said, there are other
Speaker 1: applications that we kind of just hinted at, but yeah,
Speaker 1: I think that we could do lots more episodes about. So, yeah,
Speaker 1: if you have a specific application of ultrasonic technology that
Speaker 1: you want us to cover. You know, maybe there's some
Speaker 1: some wacky technology you've heard about, but you you don't
Speaker 1: know a lot about it. You want to hear us
Speaker 1: talk about it. Let's know. That's an email, all right,
Speaker 1: dress as tech stunk at Discovery dot com or drops
Speaker 1: the line on Facebook, Twitter or Tumbler. Our handle at
Speaker 1: all three is tech stuff, hs W and Lauren and
Speaker 1: I will talk to you again really soon for more
Speaker 1: on this and thousands of other topics. Because it has
Speaker 1: to work dot com