WEBVTT - How Ultrasound Works 0:00:04.240 --> 0:00:07.200 Get in touch with technology with text stuff from how 0:00:07.240 --> 0:00:13.720 stuff works dot com. Hey there, everyone, and welcome to 0:00:13.920 --> 0:00:17.040 tex Stuff. I'm Jonathan Strickland, and I'm learning focal bind. 0:00:17.079 --> 0:00:20.600 Today we're going to talk about a technology that uses 0:00:20.800 --> 0:00:25.640 h uses sound really really super high pitch sound ultrasound 0:00:25.800 --> 0:00:28.400 in fact, yeah, which you know, first I thought was 0:00:28.440 --> 0:00:31.360 something that only transformers could make, as in the characters, 0:00:31.440 --> 0:00:35.680 not the actual devices that change voltages. And that's what 0:00:35.760 --> 0:00:38.440 I figured you meant. Okay, Well, I have to make 0:00:38.440 --> 0:00:40.919 sure you know I don't we do. We do try 0:00:40.920 --> 0:00:43.800 to be scientific here, yes, all right. So, as it 0:00:43.800 --> 0:00:46.800 turns out, humans have a certain range of sounds that 0:00:46.960 --> 0:00:50.160 a typical human can hear, keeping in mind that different 0:00:50.159 --> 0:00:52.800 people can hear different ranges. Some may be able to 0:00:52.800 --> 0:00:56.040 hear a larger range, some people like me are starting 0:00:56.040 --> 0:00:58.720 to lose some of that range, and some people are 0:00:58.720 --> 0:01:01.400 better at lower higher range. Is sure, um that the 0:01:01.440 --> 0:01:04.800 average is about twenty to twenty thousand hurts at the 0:01:04.880 --> 0:01:08.559 low and high end, right, So beyond twenty thousand hurts 0:01:08.640 --> 0:01:13.160 like usually significantly beyond twenty thousand hurts at those higher frequencies. 0:01:13.200 --> 0:01:16.240 We call that ultrasonic. Oh well, you don't quite get 0:01:16.280 --> 0:01:19.360 into ultrasonic um right away. I mean, I mean, you know, 0:01:19.480 --> 0:01:21.319 you've still got a good audible range. I mean like 0:01:21.360 --> 0:01:23.920 beluga whales, for example, can hear up to some like 0:01:23.959 --> 0:01:26.600 a hundred and twenty thousand hurts, but that is still 0:01:26.640 --> 0:01:29.920 not ultrasonic. Well, the true ultrasonic that we're looking at, 0:01:29.959 --> 0:01:33.400 for at least the the technology we'll be talking about 0:01:33.440 --> 0:01:36.440 today is in the one to one point five million 0:01:36.520 --> 0:01:40.600 hurts or mega hurts range. So that's where we're getting 0:01:40.600 --> 0:01:42.640 to a point where you know, animals are not detecting 0:01:42.640 --> 0:01:44.560 this kind of sound. It's not a pitch that's much 0:01:44.640 --> 0:01:48.360 higher than a frequency that's much higher frequency in pitch 0:01:48.400 --> 0:01:52.440 I'm I'm using almost interchangeably, which is a little this misleading, 0:01:52.440 --> 0:01:56.240 but you get what I'm saying. So this is a 0:01:56.280 --> 0:02:00.280 technology that's very much based in some part on something 0:02:00.320 --> 0:02:03.520 that actual animals are using. Some animals are using right 0:02:03.600 --> 0:02:06.640 eocation yep. And so that's something you probably heard about 0:02:06.680 --> 0:02:10.160 whenever you've you heard about things like bats or dolphins 0:02:10.200 --> 0:02:14.239 or whales, they all use echolocation as either a primary 0:02:14.320 --> 0:02:16.640 way of figuring out what their environments like in the 0:02:16.680 --> 0:02:19.280 case of bats, or you know, one of the many 0:02:19.320 --> 0:02:23.040 senses that they rely upon to explore their environments. Right. 0:02:23.240 --> 0:02:26.040 Humans also use this in the form of sonar or 0:02:26.120 --> 0:02:29.520 I mean really technically radar, because we're talking about electromagnetic 0:02:29.560 --> 0:02:35.840 waves and waves, so yeah, but some are specifically is 0:02:36.080 --> 0:02:39.119 so that is like a sonic wave. So uh. In fact, 0:02:39.160 --> 0:02:43.359 sonar was a very important development in our history because radar, 0:02:43.440 --> 0:02:45.880 as it turns out, was not the best thing to 0:02:46.040 --> 0:02:49.280 use for underwater because you have a tinuation of those 0:02:49.320 --> 0:02:51.240 waves and you could never be really sure that the 0:02:51.280 --> 0:02:54.280 signals you were getting back were really accurate. Sonar is 0:02:54.480 --> 0:02:58.200 a much more accurate means of determining where something is 0:02:58.320 --> 0:03:01.160 underwater and whether it's moving towards you moving away. We'll 0:03:01.160 --> 0:03:03.240 talk about more of that as we get further into 0:03:03.240 --> 0:03:06.760 this podcast, because some of those basic principles really determine 0:03:06.840 --> 0:03:11.160 some pretty cool uses of ultrasonic technology. Yeah, all of 0:03:11.200 --> 0:03:15.239 all of that history really builds upon the terrific baby 0:03:15.320 --> 0:03:18.239 viewing devices that we know and love today. Um, although 0:03:18.280 --> 0:03:21.400 that is certainly not the only use for ultrasound, as 0:03:21.440 --> 0:03:23.520 we will also get into. Yeah, I have a favorite 0:03:23.520 --> 0:03:25.799 one that I'll mention at the end. So, and it's 0:03:25.840 --> 0:03:27.679 one that I've talked about before on tech stuff. But 0:03:27.760 --> 0:03:31.000 that's okay. I don't mind repeating myself. All of you 0:03:31.120 --> 0:03:33.040 listeners out there who've been around for a while you 0:03:33.080 --> 0:03:36.160 know this, so I appreciate that you you humor me. 0:03:36.480 --> 0:03:38.360 I'm glad that you know this about yourself. John, Well, 0:03:38.400 --> 0:03:41.520 you know it's you reach a certain age, you come 0:03:41.560 --> 0:03:44.360 to some truths. So first, before I even dive into 0:03:44.440 --> 0:03:47.000 the history of ultrasonic technology, I have to give a 0:03:47.000 --> 0:03:50.720 shout out to Dr Jim Sung. He has a presentation 0:03:50.720 --> 0:03:54.200 online called the History of Ultrasound and Technological Advances that 0:03:54.280 --> 0:03:58.000 gave me a lot of insight into the the discoveries 0:03:58.040 --> 0:04:01.840 that lead to ultrasonic technol aology, and that's where I 0:04:02.200 --> 0:04:05.120 drew a lot of this information. So big to him, 0:04:05.240 --> 0:04:10.440 really really good, clear, yes, very very simple kind of presentation. 0:04:10.480 --> 0:04:12.960 I did, you know, augment that with extra research, but 0:04:13.040 --> 0:04:17.960 it was a great starting point. So in sevento that's 0:04:17.960 --> 0:04:20.320 where we have a fellow by the name of Lazaro 0:04:20.440 --> 0:04:25.560 Spaladzani who was observing the behavior of bats, and as 0:04:25.640 --> 0:04:29.320 he was observing their behavior, he began to hypothesize what 0:04:29.400 --> 0:04:33.920 it was that allowed bats to navigate through really dark terrain, 0:04:34.320 --> 0:04:36.839 being able to avoid things, be able to zero in 0:04:37.080 --> 0:04:40.680 on prey. And as he thought about it, he came 0:04:40.720 --> 0:04:43.040 up with this hypothesis that perhaps they were making these 0:04:43.520 --> 0:04:47.039 very high pitched noises that were not necessarily within the 0:04:47.120 --> 0:04:48.800 range of human hearing. You might be able to hear 0:04:48.800 --> 0:04:50.840 a few squeaks now and then, but that's about it, 0:04:51.200 --> 0:04:55.359 But that they were also uh, reacting to the echoes 0:04:55.560 --> 0:04:58.080 of those noises to hone in on things or to 0:04:58.160 --> 0:05:01.080 avoid obstacles, all right, to find about how far away 0:05:01.240 --> 0:05:04.880 or possibly even how big an obstacle or a predator 0:05:05.000 --> 0:05:07.320 or a piece of prey would be away from them. Yeah, 0:05:07.320 --> 0:05:10.279 because if if you're if you're hearing an echo come back, 0:05:10.360 --> 0:05:12.880 but it's not nearly as powerful as the sounds you 0:05:12.960 --> 0:05:16.240 put out your your the result might be, oh, that 0:05:16.279 --> 0:05:18.880 thing is close, but it's also small. If you get 0:05:18.920 --> 0:05:21.080 a lot of signal back, you're like, Okay, there's something 0:05:21.080 --> 0:05:23.640 with a lot of surface area that's not too far away, 0:05:23.680 --> 0:05:25.839 and perhaps I don't want to go in that direction anymore. 0:05:26.360 --> 0:05:29.800 So he kind of, you know, was the one to 0:05:29.920 --> 0:05:36.960 propose this hypothesis of echolocation. Now that's again one of 0:05:36.960 --> 0:05:39.560 those basic principles that we would build upon to get 0:05:39.600 --> 0:05:43.280 to ultrasonic technology. In eighteen twenty six, you have Jean 0:05:43.440 --> 0:05:47.400 Daniel Calladon who was performing a series of experiments using 0:05:47.560 --> 0:05:49.800 a bell like a church bell. It was actually a 0:05:49.839 --> 0:05:54.600 church bell that he put underwater. He had a another 0:05:54.680 --> 0:05:56.800 little lever that had a striker on the end of 0:05:56.800 --> 0:06:00.240 it to strike the bell. So if you like to 0:06:00.279 --> 0:06:02.680 imagine as one of those you remember then the cartoons, 0:06:02.720 --> 0:06:05.160 the boxing glove that's on the like accordion type thing 0:06:05.320 --> 0:06:07.920 stretches out. That's essentially what I imagined this to be. 0:06:08.040 --> 0:06:10.719 I'm sure that's exactly what it was not according to 0:06:10.760 --> 0:06:13.440 the illustration I saw, but those things are never accurate. 0:06:13.520 --> 0:06:16.760 So anyway, there's this bell that's underneath the water, and 0:06:16.800 --> 0:06:19.080 he has a striker under the water as well. And 0:06:19.120 --> 0:06:23.440 then about ten miles away, according to the illustration, there 0:06:23.480 --> 0:06:25.400 was a second person in a boat who had a 0:06:25.480 --> 0:06:27.640 tube that went down into the water and they would 0:06:27.760 --> 0:06:29.640 essentially put their ear to the tube to listen in 0:06:29.800 --> 0:06:31.760 like an ear earpiece and ear phone, yes, so that 0:06:31.800 --> 0:06:34.960 they could you would amplify any sounds they could maybe 0:06:35.080 --> 0:06:37.039 you know their and their job was to listen for 0:06:37.920 --> 0:06:42.880 the tone of the bell, and so uh, he would 0:06:43.000 --> 0:06:45.880 call it on strikes the bell, the person in the 0:06:45.920 --> 0:06:50.080 other boat writes down exactly when they heard the tone. 0:06:50.480 --> 0:06:52.640 And the idea here was actually for a call it 0:06:52.800 --> 0:06:56.159 on to show that the sound would travel at a 0:06:56.200 --> 0:06:58.960 different speed through water that it did through the air. 0:06:59.360 --> 0:07:03.400 This was us to demonstrate hypothesis that sound traveled at 0:07:03.400 --> 0:07:06.320 different speeds through different media, something that we know to 0:07:06.400 --> 0:07:09.480 be true now, right, And and in fact, it travels 0:07:09.520 --> 0:07:11.760 faster in water than it does the air. Yeah, So 0:07:11.880 --> 0:07:15.320 depending upon it how tightly packed the molecules are and 0:07:15.400 --> 0:07:17.760 whatever it is that you're looking at, sound can travel 0:07:17.840 --> 0:07:20.520 much more quickly through some media than others. And it's 0:07:20.560 --> 0:07:22.720 because it's a very it's a physical media. It's not 0:07:22.760 --> 0:07:26.520 an electromagnetic it's actual physical molecules banging into each other. 0:07:26.800 --> 0:07:29.360 So if they're more tightly packed, they banging into each 0:07:29.360 --> 0:07:32.360 other much more quickly. So in that case he was 0:07:32.400 --> 0:07:35.360 able to show that it indeed does travel at different speeds. 0:07:35.680 --> 0:07:38.400 Knowing that it travels at different speeds is also very 0:07:38.440 --> 0:07:41.640 important for the very basics of ultrasonic technology, which is 0:07:41.640 --> 0:07:46.560 why we're talking about in the first place. So eighty six, 0:07:46.600 --> 0:07:53.720 our next date is eighteen eighty we're just just scorching along. 0:07:54.400 --> 0:07:58.480 This is where Pierre and Jacques Curie discover the piece 0:07:58.520 --> 0:08:00.920 of electric effect, which we have talked about quite a 0:08:01.000 --> 0:08:03.760 few times on tech stuff. All Right, this is this 0:08:03.800 --> 0:08:06.840 winds up being useful in many applications. But so what 0:08:06.960 --> 0:08:10.840 is it? Okay? So certain types of material, like for example, 0:08:10.920 --> 0:08:16.520 quartz crystals have this this particular this particular feature where 0:08:16.920 --> 0:08:20.920 if you were to apply an electric charge to this material, 0:08:21.000 --> 0:08:25.480 it would vibrate, or if you apply a mechanical stress 0:08:25.560 --> 0:08:28.080 to this object, it will then create an electrical charge. 0:08:28.360 --> 0:08:33.920 It's this weird reaction of electricity and actual kinetic movement 0:08:34.120 --> 0:08:37.320 energy that you're gonna see between the two things. And 0:08:37.360 --> 0:08:40.920 in the case of quartz crystals, it's really really regular. 0:08:41.080 --> 0:08:42.960 You know, if you know the properties of the quartz crystal, 0:08:43.480 --> 0:08:45.480 you are good to go. You know that at a 0:08:45.480 --> 0:08:48.120 certain charge, it's always going to give off the same 0:08:48.240 --> 0:08:51.440 kind of vibration. So that's why quartz crystals are used 0:08:51.440 --> 0:08:53.760 in a lot of watches. It's actually the thing that 0:08:53.800 --> 0:08:56.319 helps keep time right right. It creates the movement in 0:08:56.400 --> 0:08:59.839 courts watches because it is so regular or so so predictable. 0:09:00.240 --> 0:09:03.760 Um it also can it's used to create a spark 0:09:03.800 --> 0:09:05.640 in the kind of gas lighters that are used for 0:09:05.720 --> 0:09:08.839 for candles or cigarettes. And also um, you know, it's 0:09:08.840 --> 0:09:11.600 being talked about for energy harvesting kind of materials that 0:09:11.640 --> 0:09:14.360 are being that are in research today right and now. 0:09:14.360 --> 0:09:18.360 In the case of ultrasonic technology, this is important because 0:09:18.400 --> 0:09:22.680 the quartz crystals are the things in most ultrasonic transducers 0:09:22.720 --> 0:09:26.000 that are creating the vibrations that themselves are these high 0:09:26.360 --> 0:09:30.120 frequency sound waves. And with something as simple as electricity 0:09:30.240 --> 0:09:34.439 or relatively simple or you know, relatively technologically um possible 0:09:34.480 --> 0:09:38.520 to put into an instrument. So also they're very important 0:09:38.559 --> 0:09:41.000 for picking the signals back up as its out. Well 0:09:41.000 --> 0:09:42.439 we'll talk more about that when we get into the 0:09:42.480 --> 0:09:44.760 actual how it works stuff, but all of this, you know, 0:09:44.880 --> 0:09:48.600 again plays into it. So nineteen fifteen you have Paul 0:09:48.720 --> 0:09:52.800 Langevin who invents the hydrophone, which again very important this 0:09:52.960 --> 0:09:55.520 in this case it's essentially a microphone that can go 0:09:55.760 --> 0:09:59.440 into the water, uh and it relies on the piece 0:09:59.480 --> 0:10:03.160 of electric fact in order to pick up signals in 0:10:03.200 --> 0:10:05.880 the water. What it's doing is it's detecting changes in pressure, 0:10:06.280 --> 0:10:08.000 which are you know, that's what you know, the sound 0:10:08.000 --> 0:10:10.360 that's moving through the water is changing the actual pressure 0:10:10.720 --> 0:10:14.439 that the this hydrophone detects. The pressure changes affect the 0:10:14.480 --> 0:10:17.840 quartz crystals inside the hydrophone, which then generates the electricity, 0:10:17.920 --> 0:10:20.640 which then goes to another device that again in turns 0:10:21.400 --> 0:10:24.080 and figure out yeah, or even convert it back over 0:10:24.080 --> 0:10:26.559 into sound so that you can listen to what's going 0:10:26.600 --> 0:10:31.560 on underneath. He got the the inspiration to really work 0:10:31.600 --> 0:10:34.840 on this after something that happened in nineteen twelve, which 0:10:34.880 --> 0:10:37.160 was when Leonardo DiCaprio sank to the bomb of the 0:10:37.200 --> 0:10:41.319 ocean and froze to death, or more historically speaking, is 0:10:41.360 --> 0:10:45.000 when the Titanic sank. I thought what I just said, Well, um, 0:10:45.280 --> 0:10:48.360 but yeah, yeah. The hydrophone was originally created in order 0:10:48.400 --> 0:10:52.400 to help detect icebergs and submarines and large World War 0:10:52.440 --> 0:10:55.080 One and World War Two. It was really important. World 0:10:55.120 --> 0:10:57.320 War two is also really when sonar I came into play. 0:10:57.360 --> 0:11:00.560 But before sonar it was really just listening or stuff 0:11:00.600 --> 0:11:02.800 that you think that should not be there and we 0:11:02.840 --> 0:11:06.000 need to get out of here. So ninety seven or 0:11:06.200 --> 0:11:09.720 right thereabouts, a man named Carl Dissick, who was a 0:11:09.760 --> 0:11:13.000 doctor with the University of Vienna, begins to work on 0:11:13.240 --> 0:11:17.559 using ultrasound as a means of diagnosing brain tumors. Now, 0:11:17.600 --> 0:11:21.320 at this time ultrasonic technology was mostly being used in 0:11:21.360 --> 0:11:26.120 those those non applications exactly. But he thought, you know, 0:11:26.640 --> 0:11:29.320 this could probably tell you more about what's going on 0:11:29.360 --> 0:11:32.280 inside a person. Human brain is filled with water. Yeah, 0:11:32.520 --> 0:11:34.720 I can, I mean essentially, yeah, I can totally figure 0:11:34.760 --> 0:11:36.720 out what's going on. Maybe if there's a tumor or something, 0:11:36.720 --> 0:11:39.840 I can detect it. Now, his approach is very different 0:11:39.960 --> 0:11:43.120 from what is used today. What we use today is 0:11:43.200 --> 0:11:48.240 a reflective technique where you send a signal through a person. 0:11:48.640 --> 0:11:52.040 It reflects off of various various stuff we'll go into 0:11:52.080 --> 0:11:55.040 more detail in the second half and bounces back and 0:11:55.080 --> 0:11:59.880 then by a receiver in the instrument right exactly, and 0:12:00.000 --> 0:12:02.559 in a computer kind of puts all that data together 0:12:02.600 --> 0:12:05.240 to make it meaningful to you. He was actually thinking 0:12:05.240 --> 0:12:08.840 about setting up two different ultrasonic transducers, one on either 0:12:08.880 --> 0:12:12.280 side of your noggeting and zapping straight through the brain. 0:12:12.760 --> 0:12:14.800 So he had a receiver on both sides and a 0:12:14.880 --> 0:12:20.280 transceiver on both sides, so you're sending signals simultaneously. And 0:12:20.320 --> 0:12:23.000 the idea was that he he thought that the reflection 0:12:23.040 --> 0:12:25.280 would never be reliable enough for you to be able 0:12:25.280 --> 0:12:27.199 to have any sort of precise idea what's going on. 0:12:27.600 --> 0:12:33.000 Other people said that his particular techniques were um muddy, 0:12:33.160 --> 0:12:35.440 like it was creating too much noise because you had 0:12:35.480 --> 0:12:40.240 these two different sources going at it, and so right right, 0:12:40.280 --> 0:12:42.959 some of it's reflected back, some of it keeps going through, 0:12:43.080 --> 0:12:46.319 and so there are people who said that the information 0:12:46.360 --> 0:12:49.480 you would get back from this particular method UH was 0:12:50.080 --> 0:12:53.679 you know, not terribly reliable. Dest because it turns out 0:12:53.679 --> 0:12:58.880 would go on to UH be drafted into the Luftwaffe 0:12:59.200 --> 0:13:02.160 during World War Two and actually would become a doctor 0:13:02.240 --> 0:13:06.760 treating head wounds for German soldiers. UM. He would continue 0:13:06.800 --> 0:13:09.960 after the war to really be a proponent of ultrasonic 0:13:10.000 --> 0:13:13.600 technology being used in the medical field. However, he continued 0:13:13.640 --> 0:13:16.440 to say that he wanted the transmission effect was more 0:13:16.480 --> 0:13:21.360 important than the reflective effect UH And ultimately some researchers 0:13:21.400 --> 0:13:24.400 at M I T determined that the method that Dosik 0:13:24.520 --> 0:13:27.000 was using was creating all this noise I was talking 0:13:27.040 --> 0:13:31.160 about before, and it really wasn't reliable. So history would 0:13:31.240 --> 0:13:35.680 end up switching gears, going the different direction and still 0:13:35.760 --> 0:13:39.160 using ultrasonic technology. But in a different implementation than he did. Yeah, 0:13:39.240 --> 0:13:42.240 and and absolutely that pioneering kind of going like, hey, 0:13:42.400 --> 0:13:44.679 human bodies are fill of liquid. We can use this 0:13:44.760 --> 0:13:47.720 technology to look at them too. Yeah, it's pretty. It's sound. 0:13:47.800 --> 0:13:50.439 It's not like it's ionizing radiation. It's not something that's 0:13:50.480 --> 0:13:53.360 gonna cause you some form of harm. It's it's a 0:13:53.360 --> 0:13:56.720 physical that There are a couple of concerns that I've 0:13:56.720 --> 0:14:00.120 heard here and there about the ultrasonic waves interfere ing 0:14:00.280 --> 0:14:03.439 or or creating small bubbles or or various things like right, right, 0:14:03.600 --> 0:14:06.440 But it's not an ionizing radiation, which is the main 0:14:06.520 --> 0:14:10.040 difference between that and other imaging. Definitely better than X rays. Yes, 0:14:10.760 --> 0:14:14.560 uh so that's when Dr George Ludvig writes a paper 0:14:14.600 --> 0:14:17.600 describing the use of an ultrasonic device to diagnose skull stones, 0:14:18.000 --> 0:14:21.240 and in nineteen fifty one, doctors Wild and Neil began 0:14:21.320 --> 0:14:25.680 publishing studies on ultrasonic characteristics of benign versus malignants, not 0:14:25.760 --> 0:14:28.080 intended as a detection tool actually, but rather as a 0:14:28.120 --> 0:14:30.640 diagnostic tool once a tumor had been found, so, in 0:14:30.680 --> 0:14:33.240 other words, to determine whether or not this tumor effect 0:14:33.280 --> 0:14:36.160 is benign or malignant. So yeah, so this is after 0:14:36.240 --> 0:14:38.880 we've already established it there is a presence of a tumor. 0:14:39.360 --> 0:14:43.160 Ninety eight we got Dr Ian Donald, who I love 0:14:43.320 --> 0:14:47.280 his technical title, which was Professor of Midwifery at the 0:14:47.360 --> 0:14:51.000 University of Glasgow. Yeah, he pioneered O B G Y 0:14:51.040 --> 0:14:53.120 and ultrasound, which is what most of us think about 0:14:53.160 --> 0:14:55.600 when we think of ultrasound devices in medical fields. I 0:14:55.640 --> 0:14:58.000 think it's it's I think for the common lay person, 0:14:58.080 --> 0:15:00.320 that is the application in which we have seen and 0:15:00.360 --> 0:15:02.320 heard it used. Yeah, and it's it's certainly one that 0:15:02.440 --> 0:15:04.840 oh no, that was kind of a sorry, didn't do 0:15:04.880 --> 0:15:07.760 it this time. So it's it's certainly the thing that 0:15:07.840 --> 0:15:10.920 we see all the time in movies and television, and 0:15:11.000 --> 0:15:13.720 you know, it's the sty it's that's the typical couple 0:15:13.760 --> 0:15:16.000 is in the hospital. This is the picture of the baby. 0:15:16.000 --> 0:15:17.880 It's also I mean I just recently saw one because 0:15:17.920 --> 0:15:20.280 my sisters have. Yeah, a lot of people are born, 0:15:21.000 --> 0:15:23.280 it turns out, Yeah, and it's a very popular way 0:15:23.320 --> 0:15:26.760 of of imaging before. I mean, you know, especially and 0:15:26.760 --> 0:15:28.280 we'll we'll go into this a little bit more later, 0:15:28.320 --> 0:15:30.080 but you know, it's it's really terrific for figuring out 0:15:30.120 --> 0:15:32.360 what's going on with a baby without doing any kind 0:15:32.360 --> 0:15:34.200 of harm to the mother or the baby. Right right, 0:15:34.240 --> 0:15:37.720 You don't want anything that could potentially disrupt development or 0:15:37.800 --> 0:15:41.720 cause other complications. Uh So, skipping way ahead, because obviously 0:15:41.800 --> 0:15:44.880 ultrasound by this time had been an established medical technology. 0:15:44.880 --> 0:15:48.040 It also was used in other applications. Will talk a 0:15:48.040 --> 0:15:51.840 little bit about that later. Uh, skipping way ahead, we 0:15:51.840 --> 0:15:55.000 get to a point where Daniel Lichtenstein pioneers a point 0:15:55.040 --> 0:15:57.760 of care long ultrasound in the I c U and 0:15:57.840 --> 0:16:00.720 says that ultrasound is the real step the scope. At 0:16:00.720 --> 0:16:04.280 this stage, we're talking about precision where uh, it was 0:16:04.440 --> 0:16:07.200 much greater than anything that desn'k ever managed. It was 0:16:07.240 --> 0:16:09.920 something where you could actually get a really accurate look 0:16:09.960 --> 0:16:13.360 and in some cases a three dimensional look at what's 0:16:13.360 --> 0:16:16.360 going on inside a person without it being invasive or 0:16:16.760 --> 0:16:19.840 terribly invasive. Because there are some there are some exceptions 0:16:19.840 --> 0:16:22.480 we'll talk about, yes, but but this is mostly thanks 0:16:22.520 --> 0:16:26.320 to advancements in computers and the digitization of ultrasound exactly. 0:16:26.680 --> 0:16:29.080 So we're gonna talk a lot more about how this 0:16:29.240 --> 0:16:31.560 actually works, what's really going on with this stuff. But 0:16:31.600 --> 0:16:34.120 before we get into that, let's take a quick break 0:16:34.160 --> 0:16:37.680 to thank our sponsor. Alright, so we're back. Let's talk 0:16:37.720 --> 0:16:41.600 about how ultrasonic technology actually works. You have to be 0:16:41.640 --> 0:16:45.200 able to have something that creates an ultrasonic signal, and 0:16:45.240 --> 0:16:47.560 it has to be able to pick up that ultrasonic signal, 0:16:47.640 --> 0:16:50.280 and then it has to be able to interpret that signal. 0:16:50.760 --> 0:16:54.600 So these are these are some important elements that again 0:16:54.640 --> 0:16:57.360 would only have been possible due to the work of 0:16:57.400 --> 0:17:01.800 the people we talked about in the first half. So, uh, 0:17:02.000 --> 0:17:04.720 your basic your basic approach here. This is before I 0:17:04.760 --> 0:17:08.480 get into any of the actual Here's the technical stuff 0:17:08.480 --> 0:17:11.359 that's going on. Is you've got a device that sends 0:17:11.400 --> 0:17:15.720 the signal out which then encounters the various tissue barriers 0:17:15.800 --> 0:17:20.960 in a person's body for ultrasonic medical imaging anyway. So, uh, 0:17:21.440 --> 0:17:26.399 as it encounters these barriers, some of those ultrasonic waves 0:17:26.440 --> 0:17:30.359 are gonna bounce back. So the machine starts to collect 0:17:30.359 --> 0:17:32.840 the data of the material of the waves that bounce back, 0:17:32.840 --> 0:17:36.000 the intensity of those waves, and the length of time 0:17:36.000 --> 0:17:37.760 it took for them to go out and bounce back, 0:17:38.200 --> 0:17:40.560 give the idea of things like the depth and the 0:17:40.680 --> 0:17:44.000 nature of the tissue itself. The uh, some of the 0:17:44.000 --> 0:17:47.040 waves will continue to penetrate into the patient's body and 0:17:47.040 --> 0:17:50.120 then bounce off other boundaries. So these boundaries are things 0:17:50.160 --> 0:17:53.719 like boundaries between liquids and soft tissue, or soft tissue 0:17:53.720 --> 0:17:57.080 and hard tissue, so and oregon and bones, that kind 0:17:57.080 --> 0:18:00.920 of thing. And as the waves go and bounce back, 0:18:01.000 --> 0:18:03.359 we start to be able to look at that data 0:18:03.400 --> 0:18:05.760 and determine what kind of tissue it was going through, 0:18:06.040 --> 0:18:09.560 because because we know that that these sound waves travel 0:18:09.600 --> 0:18:13.520 at different speeds through different types of Yeah, exactly, so 0:18:13.760 --> 0:18:16.320 by knowing, you know, if you know that sound travels 0:18:16.359 --> 0:18:18.680 at such and such a speed as it goes through bone, 0:18:19.080 --> 0:18:21.240 which we do know, I mean I don't know it. 0:18:21.400 --> 0:18:24.439 I don't We don't personally know. But human kind knows. 0:18:25.080 --> 0:18:27.680 People smarter than you know. You have that thing where 0:18:27.720 --> 0:18:29.840 you just trust that people smarter than you are working 0:18:29.880 --> 0:18:32.320 on the problem. In this case, it's true, so not 0:18:32.359 --> 0:18:35.240 so much working as much as have already completely figured out. 0:18:35.359 --> 0:18:39.760 There are charts that you can look at. So the computer, 0:18:40.000 --> 0:18:41.960 which we'll talk about in a second, takes all this 0:18:42.080 --> 0:18:44.440 data in and is able to analyze it and determine 0:18:44.760 --> 0:18:47.760 which waves were the ones that passed through liquid, which 0:18:47.760 --> 0:18:49.600 ones were the ones that passed through soft tissue, which 0:18:49.600 --> 0:18:52.919 ones passed through hard tissue, and then adding all that 0:18:52.960 --> 0:18:56.439 information together is able to create a picture that's then 0:18:56.520 --> 0:18:59.840 displayed on a display. It sends the information to it 0:18:59.880 --> 0:19:03.800 to place that you get essentially a virtual representation of 0:19:03.840 --> 0:19:07.480 whatever it is that's there. Typically it's two dimensional, so 0:19:07.560 --> 0:19:12.080 we'll talk a bit about three D. Uh ultra relatively 0:19:12.160 --> 0:19:16.440 new development, but it is certainly possible. But your traditional 0:19:16.520 --> 0:19:19.639 ultrasonic images are two dimensional. So it's kind of like 0:19:19.680 --> 0:19:22.480 a a side view or top down view, depending upon 0:19:22.520 --> 0:19:25.160 the angle that's being used and what you are specifically 0:19:25.160 --> 0:19:30.800 trying to image, right, So, uh, it's a really cool approach. Now, 0:19:30.840 --> 0:19:34.240 the parts that are on an ultrasonic machine include the 0:19:34.240 --> 0:19:36.720 transducer probra, which we've talked a little bit about. Right. 0:19:37.040 --> 0:19:39.520 This is the device that is sending and receiving the signals. Yep, 0:19:39.640 --> 0:19:41.879 that's got at least one quartz crystal in it. It 0:19:41.920 --> 0:19:44.440 may have multiple quartz crystals in it, and in fact, 0:19:44.440 --> 0:19:47.800 if it does have multiple quarts crystals, you can time 0:19:47.880 --> 0:19:51.439 the different crystals to fire at different you know, you 0:19:51.520 --> 0:19:53.960 send charges to them at different times because each one 0:19:54.000 --> 0:19:57.359 has its own independent circuit. And that allows you to 0:19:57.640 --> 0:20:01.639 quote unquote steer the trasonic beam and be able to 0:20:01.640 --> 0:20:05.280 get a lot more precision about what's going on. Um 0:20:05.400 --> 0:20:07.600 But even if it only has one crystal, I can 0:20:07.640 --> 0:20:10.280 still send and then receive. So what's happening is you 0:20:10.320 --> 0:20:13.480 send an electrical charge to the crystal. The crystal vibrates 0:20:13.480 --> 0:20:16.879 at this incredibly high frequency, which creates this ultrasonic sound 0:20:17.200 --> 0:20:20.160 like one to one point five megahurts, And you're talking 0:20:20.240 --> 0:20:24.760 about possibly millions of these in a millions of pulses 0:20:24.760 --> 0:20:27.479 in a single second. They go into the body and 0:20:27.520 --> 0:20:30.480 start to bounce off of stuff. When the sounds bounce 0:20:30.600 --> 0:20:34.520 back to the transducer probe, they hit the Courts crystal, 0:20:34.880 --> 0:20:37.720 which causes the quartz crystal to vibrate, which then causes 0:20:37.720 --> 0:20:41.120 the electric charge to emanate. So because of that piece 0:20:41.119 --> 0:20:44.080 of electric effect, it works both ways. The device picks 0:20:44.160 --> 0:20:47.359 up the electric charges and that's what it's able to 0:20:47.480 --> 0:20:50.840 use to interpret the actual data that is gathered and 0:20:50.920 --> 0:20:54.480 sent onto the computer. So the computer, it's a CPU 0:20:54.760 --> 0:20:57.520 is you know, it's a computer. It it processes data, 0:20:57.600 --> 0:21:01.119 crunches numbers, It follows specific rules that have been programmed 0:21:01.119 --> 0:21:03.800 in that take into account all the basic information that 0:21:03.840 --> 0:21:06.840 we understand about how sound travels. So that's how it's 0:21:06.840 --> 0:21:09.439 able to build the actual useful information and generates this 0:21:09.480 --> 0:21:12.560 image on the screen. Right. Then you also have controls, 0:21:12.800 --> 0:21:15.560 big surprise there, right, So the controls allow you to 0:21:15.560 --> 0:21:18.560 do things like you have a medical practitioner who's called 0:21:18.560 --> 0:21:23.639 an ultrasonographer. Um, so the ultrasonographer can adjust things like 0:21:23.680 --> 0:21:28.160 the amplitude of the ultrasonic waves, their frequency, the duration 0:21:28.400 --> 0:21:31.560 of the pulses that the transducer probe is creating. All right. 0:21:31.560 --> 0:21:34.359 That the precise frequency of the waves greatly affects the 0:21:34.359 --> 0:21:37.800 resolution of the resulting image. So this is really important, yes, 0:21:37.840 --> 0:21:40.880 it really is. It also will determine how far the 0:21:41.000 --> 0:21:44.000 pulses can penetrate. And on top of all those other things, 0:21:44.000 --> 0:21:46.480 you also have a storage medium of some sort you 0:21:46.480 --> 0:21:49.399 want to save this data. Obviously that might be on 0:21:49.440 --> 0:21:51.560