1 00:00:04,240 --> 00:00:07,240 Speaker 1: Welcome to tech Stuff, a production of I Heart Radios 2 00:00:07,320 --> 00:00:13,880 Speaker 1: How Stuff Works. Hey there, and welcome to tech Stuff. 3 00:00:13,880 --> 00:00:16,320 Speaker 1: I'm your host, Jonathan Strickland. I'm an executive producer with 4 00:00:16,360 --> 00:00:19,919 Speaker 1: iHeart Radio and I love all things tech and guys, 5 00:00:20,160 --> 00:00:24,560 Speaker 1: I have been traveling all over the United States as 6 00:00:24,640 --> 00:00:29,120 Speaker 1: part of another podcast I do called The Restless Ones. 7 00:00:29,160 --> 00:00:31,440 Speaker 1: If you've not checked that out, you should definitely give 8 00:00:31,480 --> 00:00:34,640 Speaker 1: it a listen. I talked to chief technology officers, chief 9 00:00:34,640 --> 00:00:38,760 Speaker 1: information officers, chief data officers, these really super smart folks 10 00:00:39,040 --> 00:00:43,400 Speaker 1: who are shaping the way technology affects business, which means, 11 00:00:43,400 --> 00:00:47,760 Speaker 1: in turn, it affects us. That show has been fantastic 12 00:00:47,880 --> 00:00:50,480 Speaker 1: and a lot of work. It's also meant that I've 13 00:00:50,560 --> 00:00:54,280 Speaker 1: been traveling a ton, so unfortunately, because of that, I 14 00:00:54,320 --> 00:00:57,680 Speaker 1: didn't really have the time to fully research and write 15 00:00:57,720 --> 00:01:01,280 Speaker 1: and prepare an episode ready to go today. So we're 16 00:01:01,280 --> 00:01:04,800 Speaker 1: going to listen to a classic episode of tech Stuff instead, 17 00:01:05,360 --> 00:01:09,120 Speaker 1: because I would rather do that than present a rushed, 18 00:01:10,480 --> 00:01:12,920 Speaker 1: jerky kind of episode where you listen to it and 19 00:01:12,959 --> 00:01:15,720 Speaker 1: think he didn't even put forth any effort. I always 20 00:01:15,720 --> 00:01:19,320 Speaker 1: want to give you the best I can, so don't worry. 21 00:01:19,360 --> 00:01:21,679 Speaker 1: New episodes of tech Stuff are right around the corner. 22 00:01:22,000 --> 00:01:24,440 Speaker 1: I just didn't have it in me to get one 23 00:01:24,440 --> 00:01:26,679 Speaker 1: out for today. So we're going to look back on 24 00:01:26,720 --> 00:01:31,800 Speaker 1: a classic. This classic episode originally published on January two 25 00:01:31,840 --> 00:01:35,800 Speaker 1: thousand fourteen, and it's called How Ultrasound Works, And I 26 00:01:35,800 --> 00:01:38,440 Speaker 1: sat down with Lauren Vogelbaum, who was my co host 27 00:01:38,480 --> 00:01:42,400 Speaker 1: at the time, to really talk about ultrasonic technology and 28 00:01:42,440 --> 00:01:44,920 Speaker 1: what it's used for. I hope you guys enjoy it. 29 00:01:45,120 --> 00:01:48,240 Speaker 1: Take a listen. As it turns out, humans have a 30 00:01:48,280 --> 00:01:51,760 Speaker 1: certain range of sounds that a typical human can hear. 31 00:01:51,960 --> 00:01:54,840 Speaker 1: Keeping in mind that different people can hear different ranges. 32 00:01:55,160 --> 00:01:57,480 Speaker 1: Some may be able to hear a larger range, some 33 00:01:57,520 --> 00:02:01,120 Speaker 1: people like me are starting to lose some of that range, 34 00:02:01,160 --> 00:02:03,559 Speaker 1: and some people are better at lower higher ranges. Sure, 35 00:02:03,720 --> 00:02:07,040 Speaker 1: um that the average is about twenty to twenty thousand 36 00:02:07,120 --> 00:02:10,360 Speaker 1: hurts at the low and high end, right, So beyond 37 00:02:10,680 --> 00:02:15,040 Speaker 1: twenty thousand hurts, like usually significantly beyond twenty thousand hurts 38 00:02:15,080 --> 00:02:18,760 Speaker 1: at those higher frequencies. We call that ultrasonic. Well, you 39 00:02:18,760 --> 00:02:22,240 Speaker 1: don't quite get into ultrasonicum right away. I mean, I mean, 40 00:02:22,280 --> 00:02:24,320 Speaker 1: you know you've still got a good audible range. I mean, 41 00:02:24,320 --> 00:02:26,800 Speaker 1: like Bluga whales, for example, can hear up to some 42 00:02:26,960 --> 00:02:29,440 Speaker 1: like a hundred and twenty thousand hurts, but that is 43 00:02:29,440 --> 00:02:33,000 Speaker 1: still not ultrasonic. Well, the true ultrasonic that we're looking at, 44 00:02:33,040 --> 00:02:36,520 Speaker 1: for at least the the technology we'll be talking about 45 00:02:36,520 --> 00:02:39,520 Speaker 1: today is in the one to one point five million 46 00:02:39,600 --> 00:02:43,680 Speaker 1: hurts or mega hurts range. So that's where we're getting 47 00:02:43,680 --> 00:02:45,720 Speaker 1: to a point where you know, animals are not detecting 48 00:02:45,760 --> 00:02:48,760 Speaker 1: this kind of sounded a pitch that's much higher than 49 00:02:49,440 --> 00:02:52,079 Speaker 1: a frequency that's much higher frequency and pitch I'm using 50 00:02:52,080 --> 00:02:56,680 Speaker 1: almost interchangeably, which is little dis misleading, but you get 51 00:02:56,720 --> 00:03:00,440 Speaker 1: what I'm saying. So this is a technology it's very 52 00:03:00,520 --> 00:03:04,600 Speaker 1: much based in some part on something that actual animals 53 00:03:04,639 --> 00:03:08,480 Speaker 1: are using. Some animals are using, right yep. And so 54 00:03:08,560 --> 00:03:11,280 Speaker 1: that's something you probably heard about whenever you've you heard 55 00:03:11,280 --> 00:03:14,200 Speaker 1: about things like bats or dolphins or whales. They all 56 00:03:14,320 --> 00:03:18,520 Speaker 1: use echolocation as either a primary way of figuring out 57 00:03:18,600 --> 00:03:20,679 Speaker 1: what their environments like in the case of bats, or 58 00:03:20,960 --> 00:03:23,560 Speaker 1: you know, one of the many senses that they rely 59 00:03:23,720 --> 00:03:27,720 Speaker 1: upon to explore their environments. Right. Humans also use this 60 00:03:27,800 --> 00:03:30,200 Speaker 1: in the form of sonar or I mean really technically 61 00:03:30,280 --> 00:03:37,119 Speaker 1: radar because we're talking about electromagnetic waves and waves, so yeah, 62 00:03:37,160 --> 00:03:40,240 Speaker 1: but some are specifically is so that is like a 63 00:03:40,280 --> 00:03:43,320 Speaker 1: sonic wave. So uh. In fact, sonar was a very 64 00:03:43,360 --> 00:03:47,280 Speaker 1: important development in our history because radar, as it turns out, 65 00:03:47,720 --> 00:03:50,720 Speaker 1: was not the best thing to use for underwater because 66 00:03:51,000 --> 00:03:53,160 Speaker 1: you have a tinuation of those waves and you could 67 00:03:53,200 --> 00:03:55,160 Speaker 1: never be really sure that the signals you were getting 68 00:03:55,160 --> 00:03:58,640 Speaker 1: back were really accurate. Sonar is a much more accurate 69 00:03:58,800 --> 00:04:02,400 Speaker 1: means of determining where something is underwater and whether it's 70 00:04:02,440 --> 00:04:04,880 Speaker 1: moving towards you or moving away. We'll talk about more 71 00:04:04,960 --> 00:04:07,160 Speaker 1: of that as we get further into this podcast, because 72 00:04:07,160 --> 00:04:10,760 Speaker 1: some of those basic principles really determine some pretty cool 73 00:04:11,200 --> 00:04:14,680 Speaker 1: uses of ultrasonic technology. Yeah, all of all of that 74 00:04:14,880 --> 00:04:19,400 Speaker 1: history really builds upon the terrific baby viewing devices that 75 00:04:19,440 --> 00:04:22,200 Speaker 1: we know and love today. Um, although that is certainly 76 00:04:22,200 --> 00:04:25,120 Speaker 1: not the only use for ultrasound, as we will also 77 00:04:25,160 --> 00:04:27,080 Speaker 1: get into. Yeah, I have a favorite one that I'll 78 00:04:27,080 --> 00:04:29,400 Speaker 1: mention at the end. So, and it's one that I've 79 00:04:29,400 --> 00:04:31,840 Speaker 1: talked about before on tech stuff. But that's okay, I 80 00:04:31,920 --> 00:04:34,800 Speaker 1: don't mind repeating myself. All of you listeners out there 81 00:04:34,800 --> 00:04:36,920 Speaker 1: who've been around for a while, you know this, so 82 00:04:37,480 --> 00:04:40,159 Speaker 1: I appreciate that you humor me. I'm glad that you 83 00:04:40,160 --> 00:04:42,919 Speaker 1: know this about yourself. John. Well, you know it's you 84 00:04:42,960 --> 00:04:45,960 Speaker 1: reach a certain age, you come to some truths. So first, 85 00:04:46,040 --> 00:04:49,400 Speaker 1: before I even dive into the history of ultrasonic technology, 86 00:04:49,440 --> 00:04:51,760 Speaker 1: I have to give a shout out to Dr Jim Sung. 87 00:04:52,720 --> 00:04:55,960 Speaker 1: He has a presentation online called the History of Ultrasound 88 00:04:55,960 --> 00:04:58,679 Speaker 1: and Technological Advances that gave me a lot of insight 89 00:04:58,760 --> 00:05:03,840 Speaker 1: into the the the discoveries that led to ultrasonic technology. 90 00:05:04,000 --> 00:05:06,520 Speaker 1: And that's where I drew a lot of this information. 91 00:05:06,680 --> 00:05:11,320 Speaker 1: So big up to him, really really good, clear, yes, 92 00:05:11,440 --> 00:05:14,240 Speaker 1: very very simple kind of presentation. I did, you know, 93 00:05:14,279 --> 00:05:16,760 Speaker 1: augment that with extra research, but it was a great 94 00:05:16,760 --> 00:05:22,120 Speaker 1: starting point. So in sevento that's where we have a 95 00:05:22,160 --> 00:05:26,640 Speaker 1: fellow by the name of Lazaro Spaladzani who was observing 96 00:05:26,640 --> 00:05:30,039 Speaker 1: the behavior of bats, and as he was observing their behavior, 97 00:05:30,080 --> 00:05:33,760 Speaker 1: he began to hypothesize what it was that allowed bats 98 00:05:33,800 --> 00:05:38,920 Speaker 1: to navigate through really dark terrain, being able to avoid things, 99 00:05:38,920 --> 00:05:42,320 Speaker 1: being able to zero in on prey. And as he 100 00:05:42,520 --> 00:05:45,000 Speaker 1: thought about it, he came up with this hypothesis that 101 00:05:45,040 --> 00:05:48,320 Speaker 1: perhaps they were making these very high pitched noises that 102 00:05:48,360 --> 00:05:51,240 Speaker 1: were not necessarily within the range of human hearing. You 103 00:05:51,320 --> 00:05:53,120 Speaker 1: might be able to hear a few squeaks now and then, 104 00:05:53,160 --> 00:05:56,640 Speaker 1: but that's about it. But that they were also uh, 105 00:05:56,760 --> 00:06:00,400 Speaker 1: reacting to the echoes of those noises to owne in 106 00:06:00,440 --> 00:06:03,159 Speaker 1: on things or to avoid obstacles, a right to find 107 00:06:03,160 --> 00:06:06,200 Speaker 1: out how far away or possibly even how big an 108 00:06:06,200 --> 00:06:09,360 Speaker 1: obstacle or a predator or a piece of prey would 109 00:06:09,440 --> 00:06:11,560 Speaker 1: be away from them. Yeah, because if if you're if 110 00:06:11,600 --> 00:06:14,560 Speaker 1: you're hearing an echo come back, but it's not nearly 111 00:06:14,720 --> 00:06:17,400 Speaker 1: as powerful as the sound you put out your your 112 00:06:18,200 --> 00:06:20,159 Speaker 1: The result might be, oh, that thing is close, but 113 00:06:20,160 --> 00:06:23,040 Speaker 1: it's also small. If you get a lot of signal back, 114 00:06:23,080 --> 00:06:25,040 Speaker 1: you're like, Okay, there's something with a lot of surface 115 00:06:25,080 --> 00:06:27,560 Speaker 1: area that's not too far away, and perhaps I don't 116 00:06:27,560 --> 00:06:30,760 Speaker 1: want to go in that direction anymore. So he kind of, 117 00:06:31,400 --> 00:06:34,960 Speaker 1: you know, was the one to propose this hypothesis of echolocation. 118 00:06:38,120 --> 00:06:41,440 Speaker 1: Now that's again one of those basic principles that we 119 00:06:41,480 --> 00:06:44,920 Speaker 1: would build upon to get to ultrasonic technology. In eighteen 120 00:06:44,960 --> 00:06:48,760 Speaker 1: twenty six, you have Jean Daniel Calladon who was performing 121 00:06:48,760 --> 00:06:52,160 Speaker 1: a series of experiments using a bell like a church bell. 122 00:06:52,320 --> 00:06:54,880 Speaker 1: It was actually a church bell that he put underwater. 123 00:06:55,760 --> 00:06:59,360 Speaker 1: He had a another little lever that had a striker 124 00:06:59,440 --> 00:07:01,920 Speaker 1: on the end of it to strike the bell. So 125 00:07:02,480 --> 00:07:04,560 Speaker 1: if you I like to imagine as one of those 126 00:07:04,560 --> 00:07:06,880 Speaker 1: you remember then the cartoons, the boxing glove that's on 127 00:07:06,960 --> 00:07:10,040 Speaker 1: the like accordion type thing stretches out. That's essentially what 128 00:07:10,120 --> 00:07:12,400 Speaker 1: I imagined this to be. I'm sure that's exactly what 129 00:07:12,440 --> 00:07:15,480 Speaker 1: it was, not according to the illustration I saw, but 130 00:07:15,520 --> 00:07:18,280 Speaker 1: those things are never accurate. So anyway, there's this bell 131 00:07:18,360 --> 00:07:20,880 Speaker 1: that's underneath the water, and he has a striker under 132 00:07:20,920 --> 00:07:24,680 Speaker 1: the water as well. And then about ten miles away, 133 00:07:24,720 --> 00:07:27,520 Speaker 1: according to the illustration, there was a second person in 134 00:07:27,560 --> 00:07:29,920 Speaker 1: a boat who had a tube that went down into 135 00:07:29,920 --> 00:07:31,760 Speaker 1: the water and they would essentially put their ear to 136 00:07:31,800 --> 00:07:34,560 Speaker 1: the tube to listen in like an ear earpiece and earphone, yes, 137 00:07:34,680 --> 00:07:37,440 Speaker 1: so that they could you would amplify any sounds they 138 00:07:37,480 --> 00:07:39,520 Speaker 1: could maybe you know, their and their job was to 139 00:07:39,640 --> 00:07:45,360 Speaker 1: listen for the tone of the bell, and so uh 140 00:07:45,560 --> 00:07:48,760 Speaker 1: he would call it on strikes the bell. The person 141 00:07:48,800 --> 00:07:52,400 Speaker 1: in the other boat writes down exactly when they heard 142 00:07:52,440 --> 00:07:55,640 Speaker 1: the tone, and the idea here was actually for call 143 00:07:55,680 --> 00:07:59,120 Speaker 1: it on to show that the sound would travel at 144 00:07:59,160 --> 00:08:02,040 Speaker 1: a different speed through water that it did through the air. 145 00:08:02,440 --> 00:08:06,480 Speaker 1: This was just to demonstrate hypothesis that sound traveled at 146 00:08:06,520 --> 00:08:09,440 Speaker 1: different speeds through different media, something that we know to 147 00:08:09,480 --> 00:08:12,600 Speaker 1: be true now, right, And and in fact, it travels 148 00:08:12,600 --> 00:08:14,840 Speaker 1: faster in water than it does the air. Yeah, So 149 00:08:14,960 --> 00:08:18,800 Speaker 1: depending upon how tightly packed the molecules are and whatever 150 00:08:18,840 --> 00:08:21,120 Speaker 1: it is that you're looking at, sound can travel much 151 00:08:21,160 --> 00:08:23,880 Speaker 1: more quickly through some media than others. And it's because 152 00:08:23,920 --> 00:08:25,920 Speaker 1: it's a very it's a physical media. It's not an 153 00:08:25,960 --> 00:08:29,960 Speaker 1: electromagnetic it's actual physical molecules banging into each other. So 154 00:08:30,000 --> 00:08:32,560 Speaker 1: if they're more tightly packed, they banging into each other 155 00:08:32,679 --> 00:08:35,680 Speaker 1: much more quickly. So in that case he was able 156 00:08:35,720 --> 00:08:38,400 Speaker 1: to show that it indeed does travel at different speeds. 157 00:08:38,760 --> 00:08:41,480 Speaker 1: Knowing that it travels at different speeds is also very 158 00:08:41,520 --> 00:08:44,720 Speaker 1: important for the very basics of ultrasonic technology, which is 159 00:08:44,720 --> 00:08:48,520 Speaker 1: why we're talking about in the first place. So the 160 00:08:48,720 --> 00:08:54,319 Speaker 1: eighty six, our next date is eighteen eighty. We're just 161 00:08:54,320 --> 00:08:59,000 Speaker 1: just scorching through history along. This is where Pierre and 162 00:08:59,160 --> 00:09:02,840 Speaker 1: Jacques Curi discover the piece of electric effect, which we 163 00:09:02,880 --> 00:09:05,600 Speaker 1: have talked about quite a few times on tech stuff. 164 00:09:05,720 --> 00:09:07,960 Speaker 1: All right, this is this winds up being useful in 165 00:09:07,960 --> 00:09:11,560 Speaker 1: many applications. But so what is it? Okay, So certain 166 00:09:11,600 --> 00:09:16,079 Speaker 1: types of material, like for example, quartz crystals have this 167 00:09:16,080 --> 00:09:20,680 Speaker 1: this particular this particular feature where if you were to 168 00:09:20,760 --> 00:09:24,960 Speaker 1: apply an electric charge to this material, it would vibrate, 169 00:09:25,360 --> 00:09:29,320 Speaker 1: or if you apply a mechanical stress to this object, 170 00:09:29,400 --> 00:09:32,320 Speaker 1: it will then create an electrical charge. It's this weird 171 00:09:33,000 --> 00:09:37,920 Speaker 1: reaction of electricity and actual kinetic movement energy that you're 172 00:09:37,920 --> 00:09:41,000 Speaker 1: gonna see between the two things. And in the case 173 00:09:41,040 --> 00:09:44,600 Speaker 1: of quartz crystals, it's really really regular. You know, if 174 00:09:44,600 --> 00:09:47,080 Speaker 1: you know the properties of the quartz crystal, you are 175 00:09:47,200 --> 00:09:49,200 Speaker 1: good to go. You know that at a certain charge, 176 00:09:49,200 --> 00:09:52,280 Speaker 1: it's always going to give off the same kind of vibration. 177 00:09:52,679 --> 00:09:54,880 Speaker 1: So that's why quartz crystals are used in a lot 178 00:09:54,920 --> 00:09:57,720 Speaker 1: of watches. It's actually the thing that helps keep time 179 00:09:58,120 --> 00:10:00,480 Speaker 1: right right. It creates the movement in courts watch because 180 00:10:00,480 --> 00:10:03,600 Speaker 1: it is so regular or so um, so predictable. Um. 181 00:10:03,640 --> 00:10:06,959 Speaker 1: It also can it's used to create a spark in 182 00:10:07,000 --> 00:10:08,920 Speaker 1: the kind of gas lighters that are used for for 183 00:10:08,960 --> 00:10:12,120 Speaker 1: candles or cigarettes, and also um, you know, it's being 184 00:10:12,160 --> 00:10:14,880 Speaker 1: talked about for energy harvesting kind of materials that are 185 00:10:14,960 --> 00:10:17,560 Speaker 1: being that are in research today right and now. In 186 00:10:17,600 --> 00:10:21,640 Speaker 1: the case of ultrasonic technology, this is important because the 187 00:10:21,760 --> 00:10:25,880 Speaker 1: quartz crystals are the things in most ultrasonic transducers that 188 00:10:25,920 --> 00:10:30,080 Speaker 1: are creating the vibrations that themselves are these high frequency 189 00:10:30,320 --> 00:10:33,400 Speaker 1: sound waves. And with something as simple as electricity or 190 00:10:33,440 --> 00:10:37,640 Speaker 1: relatively simple or you know, relatively technologically um possible to 191 00:10:37,760 --> 00:10:41,760 Speaker 1: put into an instrument. So also they're very important for 192 00:10:41,800 --> 00:10:44,240 Speaker 1: picking the signals back up as its out. Well, we'll 193 00:10:44,280 --> 00:10:45,880 Speaker 1: talk more about that when we get into the actual 194 00:10:45,880 --> 00:10:47,880 Speaker 1: how it works stuff, but all of this, you know, 195 00:10:48,000 --> 00:10:51,720 Speaker 1: again plays into it. So nineteen fift you have Paul 196 00:10:51,800 --> 00:10:55,920 Speaker 1: Langevin who invents the hydrophone, which again very important this 197 00:10:56,040 --> 00:10:58,600 Speaker 1: in this case, it's essentially a microphone that can go 198 00:10:58,880 --> 00:11:02,560 Speaker 1: into the water, uh and it relies on the piece 199 00:11:02,559 --> 00:11:06,240 Speaker 1: of electric effect in order to pick up signals in 200 00:11:06,280 --> 00:11:08,960 Speaker 1: the water. What's doing is it's detecting changes in pressure, 201 00:11:09,360 --> 00:11:11,040 Speaker 1: which are you know, that's what you know, the sound 202 00:11:11,080 --> 00:11:13,440 Speaker 1: that's moving through the water is changing the actual pressure 203 00:11:13,800 --> 00:11:17,520 Speaker 1: that the this hydrophone detects. The pressure changes affect the 204 00:11:17,600 --> 00:11:20,920 Speaker 1: quartz crystals inside the hydrophone, which then generates the electricity, 205 00:11:21,000 --> 00:11:23,680 Speaker 1: which then goes to another device that again in turns 206 00:11:24,480 --> 00:11:27,360 Speaker 1: and figure out yeah, or even converted back over into 207 00:11:27,440 --> 00:11:30,400 Speaker 1: sound so that you can listen to what's going on underneath. 208 00:11:30,920 --> 00:11:34,920 Speaker 1: He got the the inspiration to really work on this 209 00:11:35,000 --> 00:11:38,240 Speaker 1: after something that happened in nineteen twelve, which was when 210 00:11:38,440 --> 00:11:40,599 Speaker 1: Leonardo DiCaprio sank to the bombo of the ocean and 211 00:11:40,640 --> 00:11:44,720 Speaker 1: froze to death, or more historically speaking, is when the 212 00:11:44,760 --> 00:11:48,120 Speaker 1: Titanic sank. I thought, that's what I just said. Well, um, 213 00:11:48,360 --> 00:11:51,440 Speaker 1: but yeah, yeah. The hydrophone was originally created in order 214 00:11:51,520 --> 00:11:55,280 Speaker 1: to help detect icebergs and submarines in other large World 215 00:11:55,320 --> 00:11:57,720 Speaker 1: War One and World War Two. It was really important. 216 00:11:57,920 --> 00:11:59,880 Speaker 1: World War two is also really when Sonar I came 217 00:12:00,080 --> 00:12:02,880 Speaker 1: to play. But before sonar it was really just listening 218 00:12:03,000 --> 00:12:05,679 Speaker 1: for stuff that you think that should not be there 219 00:12:05,720 --> 00:12:08,480 Speaker 1: and we need to get out of here. So ninety 220 00:12:08,559 --> 00:12:12,560 Speaker 1: seven or right thereabouts, a man named Carl Dissick, who 221 00:12:12,600 --> 00:12:15,000 Speaker 1: was a doctor with the University of Vienna, begins to 222 00:12:15,480 --> 00:12:20,600 Speaker 1: work on using ultrasound as a means of diagnosing brain tumors. Now, 223 00:12:20,679 --> 00:12:24,400 Speaker 1: at this time, ultrasonic technology was mostly being used in 224 00:12:24,440 --> 00:12:29,200 Speaker 1: those those non applications exactly. But he thought, you know, 225 00:12:29,760 --> 00:12:32,400 Speaker 1: this could probably tell you more about what's going on 226 00:12:32,440 --> 00:12:34,880 Speaker 1: inside a person. The human brain is filled with water. 227 00:12:35,120 --> 00:12:37,520 Speaker 1: Yeah I can, I mean essentially, yeah, I can totally 228 00:12:37,559 --> 00:12:39,400 Speaker 1: figure out what's going on. Maybe if there's a tumor 229 00:12:39,480 --> 00:12:42,120 Speaker 1: or something, I can detect it. Now, his approach is 230 00:12:42,280 --> 00:12:45,480 Speaker 1: very different from what is used today. What we use 231 00:12:45,559 --> 00:12:50,520 Speaker 1: today is a reflective technique where you send a signal 232 00:12:50,600 --> 00:12:54,720 Speaker 1: through a person. It reflects off of various various stuff, 233 00:12:54,720 --> 00:12:57,160 Speaker 1: will go into more detail in the second half and 234 00:12:57,280 --> 00:13:01,640 Speaker 1: bounces back and then read out by a receiver in 235 00:13:01,679 --> 00:13:04,240 Speaker 1: the instrument right exactly, and then a computer kind of 236 00:13:04,480 --> 00:13:06,839 Speaker 1: puts all that data together to make it meaningful to you. 237 00:13:07,320 --> 00:13:11,439 Speaker 1: He was actually thinking about setting up two different ultrasonic transducers, 238 00:13:11,440 --> 00:13:14,800 Speaker 1: one on either side of your noggat and zapping straight 239 00:13:14,800 --> 00:13:17,319 Speaker 1: through the brain. So he had a receiver on both 240 00:13:17,360 --> 00:13:20,160 Speaker 1: sides and a transceiver on both sides, so you're sending 241 00:13:20,160 --> 00:13:25,320 Speaker 1: signals simultaneously. And the idea was that he thought that 242 00:13:25,440 --> 00:13:28,120 Speaker 1: the reflection would never be reliable enough for you to 243 00:13:28,120 --> 00:13:29,920 Speaker 1: be able to have any sort of precise idea what's 244 00:13:29,920 --> 00:13:34,559 Speaker 1: going on. Other people said that his particular techniques were 245 00:13:34,679 --> 00:13:38,319 Speaker 1: um muddy, like it was creating too much noise because 246 00:13:38,320 --> 00:13:40,679 Speaker 1: you had these two different sources going at it, and 247 00:13:40,720 --> 00:13:44,640 Speaker 1: so signals right and right, some of it's reflected back, 248 00:13:44,720 --> 00:13:47,640 Speaker 1: some of it keeps going through, and so there are 249 00:13:47,640 --> 00:13:50,079 Speaker 1: people who said that the information you would get back 250 00:13:50,120 --> 00:13:55,200 Speaker 1: from this particular method, uh was you know, not terribly reliable. 251 00:13:55,720 --> 00:13:58,960 Speaker 1: Dust because it turns out would go on to be 252 00:14:00,080 --> 00:14:04,120 Speaker 1: drafted into the Luftwaffe during World War Two and actually 253 00:14:04,160 --> 00:14:08,880 Speaker 1: would become a doctor treating head wounds for German soldiers. Um. 254 00:14:08,960 --> 00:14:11,640 Speaker 1: He would continue after the war to really be a 255 00:14:11,679 --> 00:14:16,120 Speaker 1: proponent of ultrasonic technology being used in the medical field. However, 256 00:14:16,160 --> 00:14:19,200 Speaker 1: he continued to say that he wanted the transmission effect 257 00:14:19,280 --> 00:14:22,880 Speaker 1: was more important than the reflective effect. Uh. And ultimately 258 00:14:23,520 --> 00:14:26,960 Speaker 1: some researchers at M I I T determined that the method 259 00:14:27,040 --> 00:14:29,760 Speaker 1: that Dosik was using was creating all this noise I 260 00:14:29,800 --> 00:14:32,840 Speaker 1: was talking about before, and it really wasn't reliable. So 261 00:14:33,600 --> 00:14:37,720 Speaker 1: history would end up switching gears, going the different direction 262 00:14:38,240 --> 00:14:41,320 Speaker 1: and still using ultrasonic technology, but in a different implementation 263 00:14:41,360 --> 00:14:44,480 Speaker 1: than he did. Yeah, and and absolutely that pioneering kind 264 00:14:44,520 --> 00:14:46,760 Speaker 1: of going like hey, human bodies are fill of liquid 265 00:14:46,880 --> 00:14:49,480 Speaker 1: we can use this technology to look at them too. Yeah, 266 00:14:49,560 --> 00:14:52,720 Speaker 1: it's pretty it's sound. It's not like it's ionizing radiation. 267 00:14:52,760 --> 00:14:55,400 Speaker 1: It's not something that's gonna cause you some form of harm. 268 00:14:55,680 --> 00:14:58,840 Speaker 1: It's it's a physical that. There are a couple of 269 00:14:58,880 --> 00:15:02,320 Speaker 1: concerns that I've heard here and there about the ultrasonic 270 00:15:02,320 --> 00:15:05,520 Speaker 1: waves interfering or or creating small bubbles or or various 271 00:15:05,560 --> 00:15:08,560 Speaker 1: things like right, right, But it's not an ionizing radiation, 272 00:15:08,840 --> 00:15:11,360 Speaker 1: which is the main difference between that and other imaging. 273 00:15:11,480 --> 00:15:15,400 Speaker 1: Definitely better than X rays. Yes, uh so that's when 274 00:15:15,480 --> 00:15:18,560 Speaker 1: Dr George Ludwig writes a paper describing the use of 275 00:15:18,560 --> 00:15:21,680 Speaker 1: an ultrasonic device to diagnose skull stones, and in nineteen 276 00:15:21,720 --> 00:15:25,160 Speaker 1: fifty one, doctors Wild and Neil began publishing studies on 277 00:15:25,240 --> 00:15:29,280 Speaker 1: ultrasonic characteristics of benign versus malignant breast tumors, not intended 278 00:15:29,280 --> 00:15:31,840 Speaker 1: as a detection tool actually, but rather as a diagnostic 279 00:15:31,880 --> 00:15:34,160 Speaker 1: tool once a tumor had been found, so, in other words, 280 00:15:34,200 --> 00:15:36,440 Speaker 1: to determine whether or not this tumor in fact is 281 00:15:36,480 --> 00:15:39,240 Speaker 1: benign or malignant. Right. So, yeah, so this is after 282 00:15:39,360 --> 00:15:41,680 Speaker 1: we've already established it there is a presence of a 283 00:15:41,680 --> 00:15:45,920 Speaker 1: tumor nifty eight we got Dr Ian Donald, who I 284 00:15:46,000 --> 00:15:50,320 Speaker 1: love his technical title, which was Professor of Midwifery at 285 00:15:50,320 --> 00:15:53,800 Speaker 1: the University of Glasgow. Yeah, he pioneered O B G 286 00:15:54,040 --> 00:15:55,960 Speaker 1: Y and ultrasound, which is what most of us think 287 00:15:56,000 --> 00:15:58,600 Speaker 1: about when we think of ultrasound devices in medical fields. 288 00:15:58,640 --> 00:16:01,280 Speaker 1: I think it's it's for the common lay person. That 289 00:16:01,400 --> 00:16:03,640 Speaker 1: is the application in which we have seen and heard 290 00:16:03,640 --> 00:16:05,840 Speaker 1: it used. Yeah, and it's it's certainly one that oh no, 291 00:16:06,000 --> 00:16:08,440 Speaker 1: that was kind of sorry, didn't do it this time. 292 00:16:08,800 --> 00:16:11,760 Speaker 1: So it's it's certainly the thing that we see all 293 00:16:11,760 --> 00:16:14,480 Speaker 1: the time in movies and television. And you know, it's 294 00:16:14,520 --> 00:16:17,600 Speaker 1: the sty it's that's the typical was in the hospital. 295 00:16:18,120 --> 00:16:19,560 Speaker 1: This is the picture of the baby. It's also I 296 00:16:19,560 --> 00:16:21,680 Speaker 1: mean I just recently saw one because my sisters have 297 00:16:22,240 --> 00:16:24,920 Speaker 1: a lot of people are born it turns out, Yeah, 298 00:16:24,960 --> 00:16:28,120 Speaker 1: and it's a very popular way of of imaging before. 299 00:16:28,800 --> 00:16:30,480 Speaker 1: I mean, you know, especially and we'll we'll go into 300 00:16:30,520 --> 00:16:31,880 Speaker 1: this a little bit more later, but you know, it's 301 00:16:31,920 --> 00:16:33,880 Speaker 1: it's really terrific for figuring out what's going on with 302 00:16:33,920 --> 00:16:36,000 Speaker 1: a baby without doing any kind of harm to the 303 00:16:36,000 --> 00:16:38,120 Speaker 1: mother or the baby, right, right, You don't want anything 304 00:16:38,120 --> 00:16:42,880 Speaker 1: that could potentially disrupt development or cause other complications. Uh. 305 00:16:42,920 --> 00:16:46,040 Speaker 1: So skipping way ahead because obviously ultrasound by this time 306 00:16:46,040 --> 00:16:48,800 Speaker 1: had been an established medical technology. It's also was used 307 00:16:48,800 --> 00:16:52,240 Speaker 1: in other applications. Will talk a little bit about that later. 308 00:16:52,680 --> 00:16:55,640 Speaker 1: Uh skipping way ahead, we get to a point where 309 00:16:55,720 --> 00:16:59,680 Speaker 1: Daniel Liechtenstein pioneers a point of care long ultrasound in 310 00:16:59,720 --> 00:17:02,360 Speaker 1: the ice see you and says that ultrasound is the 311 00:17:02,440 --> 00:17:07,040 Speaker 1: real stethoscope. At this stage, we're talking about precision where uh, 312 00:17:07,119 --> 00:17:10,120 Speaker 1: it was much greater than anything that desn't ever managed. 313 00:17:10,119 --> 00:17:12,160 Speaker 1: It was something where you could actually get a really 314 00:17:12,200 --> 00:17:15,640 Speaker 1: accurate look and in some cases a three dimensional look 315 00:17:16,040 --> 00:17:18,200 Speaker 1: at what's going on inside a person without it being 316 00:17:18,240 --> 00:17:22,080 Speaker 1: invasive or terribly invasive, because there are some there are 317 00:17:22,119 --> 00:17:24,800 Speaker 1: some exceptions we'll talk about, yes, But but this is 318 00:17:24,800 --> 00:17:28,240 Speaker 1: mostly thanks to advancements in computers in the digitization of 319 00:17:28,320 --> 00:17:31,560 Speaker 1: ultrasound exactly. So we're gonna talk a lot more about 320 00:17:31,600 --> 00:17:34,600 Speaker 1: how this actually works, what's really going on with this stuff. 321 00:17:34,600 --> 00:17:36,920 Speaker 1: But before we get into that, let's take a quick 322 00:17:36,960 --> 00:17:47,440 Speaker 1: break to thank our sponsor. Alright, so we're back. Let's 323 00:17:47,480 --> 00:17:51,639 Speaker 1: talk about how ultrasonic technology actually works. You have to 324 00:17:51,680 --> 00:17:54,919 Speaker 1: be able to have something that creates an ultrasonic signal, 325 00:17:55,240 --> 00:17:56,679 Speaker 1: and it has to be able to pick up that 326 00:17:56,800 --> 00:17:58,960 Speaker 1: ultrasonic signal, and then it has to be able to 327 00:17:59,000 --> 00:18:03,280 Speaker 1: interpret the signal. So these are these are some important 328 00:18:03,480 --> 00:18:06,920 Speaker 1: elements that again would only have been possible due to 329 00:18:06,960 --> 00:18:08,679 Speaker 1: the work of the people we talked about in the 330 00:18:08,720 --> 00:18:14,240 Speaker 1: first half. So, uh, your basic, your basic approach here. 331 00:18:14,320 --> 00:18:16,600 Speaker 1: This is before I get into any of the actual 332 00:18:17,280 --> 00:18:20,359 Speaker 1: Here's the technical stuff that's going on. Is you've got 333 00:18:20,400 --> 00:18:24,040 Speaker 1: a device that sends the signal out which then encounters 334 00:18:24,080 --> 00:18:28,440 Speaker 1: the various tissue barriers in a person's body for ultrasonic 335 00:18:28,480 --> 00:18:33,480 Speaker 1: medical imaging anyway. So, UH, as it encounters these barriers, 336 00:18:33,600 --> 00:18:38,880 Speaker 1: some of those ultrasonic waves are gonna bounce back. So 337 00:18:39,359 --> 00:18:41,840 Speaker 1: the machine starts to collect the data of the material 338 00:18:41,840 --> 00:18:45,040 Speaker 1: of the waves that bounce back, the intensity of those waves, 339 00:18:45,080 --> 00:18:46,919 Speaker 1: and the length of time it took for them to 340 00:18:46,960 --> 00:18:49,920 Speaker 1: go out and bounce back, give the idea of things 341 00:18:49,920 --> 00:18:52,360 Speaker 1: like the depth and the nature of the tissue itself. 342 00:18:52,840 --> 00:18:56,119 Speaker 1: The uh, some of the waves will continue to penetrate 343 00:18:56,160 --> 00:18:59,000 Speaker 1: into the patient's body and then bounce off other boundaries. 344 00:18:59,160 --> 00:19:02,240 Speaker 1: So these boundaries are things like boundaries between liquids and 345 00:19:02,280 --> 00:19:05,600 Speaker 1: soft tissue, or soft tissue and hard tissue, so and 346 00:19:05,720 --> 00:19:09,520 Speaker 1: oregon and bones, that kind of thing. And as the 347 00:19:09,560 --> 00:19:12,720 Speaker 1: waves go and bounce back, we start to be able 348 00:19:12,720 --> 00:19:14,800 Speaker 1: to look at that data and determine what kind of 349 00:19:14,800 --> 00:19:18,480 Speaker 1: tissue it was going through, because because we know that 350 00:19:18,480 --> 00:19:21,240 Speaker 1: that these sound waves travel at different speeds through different 351 00:19:21,240 --> 00:19:25,280 Speaker 1: types of Yeah, exactly, So by knowing you know, if 352 00:19:25,320 --> 00:19:27,320 Speaker 1: you know that sound travels at such and such a 353 00:19:27,359 --> 00:19:30,240 Speaker 1: speed as it goes through bone, which we know, we 354 00:19:30,280 --> 00:19:31,800 Speaker 1: do know, I mean, I don't know, if I don't, 355 00:19:32,680 --> 00:19:35,920 Speaker 1: we don't personally know. But human kind knows people smarter 356 00:19:36,040 --> 00:19:38,320 Speaker 1: than you know. You have that thing where you just 357 00:19:38,400 --> 00:19:40,600 Speaker 1: trust that people smarter than you are working on the problem. 358 00:19:40,640 --> 00:19:43,120 Speaker 1: In this case, it's true, so not so much working 359 00:19:43,160 --> 00:19:46,639 Speaker 1: as much as have already completely figured out there charts 360 00:19:46,720 --> 00:19:50,520 Speaker 1: that you can look at. So the computer, which we'll 361 00:19:50,520 --> 00:19:52,639 Speaker 1: talk about in the second, takes all this data in 362 00:19:52,720 --> 00:19:55,640 Speaker 1: and is able to analyze it and determine which waves 363 00:19:55,640 --> 00:19:58,280 Speaker 1: were the ones that passed through liquid, which ones were 364 00:19:58,280 --> 00:20:00,280 Speaker 1: the ones that passed through soft tissue, which ones passed 365 00:20:00,280 --> 00:20:04,040 Speaker 1: through hard tissue, and then adding all that information together 366 00:20:04,160 --> 00:20:07,480 Speaker 1: is able to create a picture that's been displayed on 367 00:20:07,560 --> 00:20:10,480 Speaker 1: a display. It sends the information to a display so 368 00:20:10,480 --> 00:20:14,560 Speaker 1: that you get essentially a virtual representation of whatever it 369 00:20:14,680 --> 00:20:18,320 Speaker 1: is that's there. Typically it's two dimensional, so we'll talk 370 00:20:18,359 --> 00:20:23,760 Speaker 1: a bit about three D. Uh ultra relatively new development, 371 00:20:24,040 --> 00:20:28,240 Speaker 1: but it is certainly possible. But your traditional ultrasonic images 372 00:20:28,280 --> 00:20:30,320 Speaker 1: are two dimensional. So it's kind of like a a 373 00:20:30,440 --> 00:20:33,199 Speaker 1: side view or top down view, depending upon the angle 374 00:20:33,320 --> 00:20:38,359 Speaker 1: that's being used and what you are specifically trying to image, right, So, uh, 375 00:20:38,400 --> 00:20:41,960 Speaker 1: it's a really cool approach. Now. The parts that are 376 00:20:42,160 --> 00:20:45,720 Speaker 1: on an ultrasonic machine include the transducer probra, which we've 377 00:20:45,720 --> 00:20:47,960 Speaker 1: talked a little bit about. Right. This is the device 378 00:20:48,000 --> 00:20:50,359 Speaker 1: that is sending and receiving the signals. That's got at 379 00:20:50,440 --> 00:20:53,080 Speaker 1: least one quartz crystal in it. It may have multiple 380 00:20:53,160 --> 00:20:55,000 Speaker 1: quartz crystals in it, and in fact, if it does 381 00:20:55,040 --> 00:20:59,440 Speaker 1: have multiple quarts crystals, you can time the different crystals 382 00:20:59,480 --> 00:21:02,800 Speaker 1: to file air at you send charges to them at 383 00:21:02,800 --> 00:21:05,879 Speaker 1: different times because each one has its own independent circuit, 384 00:21:06,560 --> 00:21:10,680 Speaker 1: and that allows you to quote unquote steer the ultrasonic 385 00:21:10,760 --> 00:21:13,200 Speaker 1: beam and be able to get a lot more precision 386 00:21:13,320 --> 00:21:16,840 Speaker 1: about what's going on. UM. But even if it only 387 00:21:16,840 --> 00:21:19,119 Speaker 1: has one crystal, I can still send and then receive. 388 00:21:19,200 --> 00:21:21,760 Speaker 1: So what's happening is you send an electrical charge to 389 00:21:21,800 --> 00:21:25,000 Speaker 1: the crystal. The crystal vibrates at this incredibly high frequency, 390 00:21:25,040 --> 00:21:28,400 Speaker 1: which creates this ultrasonic sound like one to one point 391 00:21:28,400 --> 00:21:32,879 Speaker 1: five mega hurts. And you're talking about possibly millions of 392 00:21:32,920 --> 00:21:35,920 Speaker 1: these and a millions of pulses in a single second. 393 00:21:36,320 --> 00:21:38,800 Speaker 1: They go into the body and start to bounce off 394 00:21:38,840 --> 00:21:42,639 Speaker 1: of stuff. When the sounds bounce back to the transducer probe, 395 00:21:43,040 --> 00:21:46,359 Speaker 1: they hit the quartz crystal, which causes the quartz crystal 396 00:21:46,440 --> 00:21:50,160 Speaker 1: to vibrate, which then causes the electric charge to emanate. 397 00:21:50,240 --> 00:21:52,399 Speaker 1: So because of that piece of electric effect, it works 398 00:21:52,400 --> 00:21:56,320 Speaker 1: both ways. The device picks up the electric charges and 399 00:21:56,400 --> 00:21:58,960 Speaker 1: that's what it's able to use to interpret the actual 400 00:21:59,080 --> 00:22:03,160 Speaker 1: data that is gathered and sent onto the computer. So 401 00:22:03,200 --> 00:22:06,359 Speaker 1: the computer, it's a CPU is you know, it's a computer. 402 00:22:06,480 --> 00:22:10,280 Speaker 1: It it processes data, crunches numbers, It follows specific rules 403 00:22:10,280 --> 00:22:12,959 Speaker 1: that have been programmed in that take into account all 404 00:22:12,960 --> 00:22:16,120 Speaker 1: the basic information that we understand about how sound travels. 405 00:22:16,400 --> 00:22:18,359 Speaker 1: So that's how it's able to build the actual useful 406 00:22:18,400 --> 00:22:21,719 Speaker 1: information and generates this image on the screen. Right. Then 407 00:22:21,760 --> 00:22:24,760 Speaker 1: you also have controls, big surprise there, right, So the 408 00:22:24,800 --> 00:22:27,240 Speaker 1: controls allow you to do things like you have a 409 00:22:27,280 --> 00:22:32,680 Speaker 1: medical practitioner who's called an ultrasonographer. Um. So the ultrasonographer 410 00:22:32,880 --> 00:22:36,719 Speaker 1: can adjust things like the amplitude of the ultrasonic waves, 411 00:22:36,720 --> 00:22:40,399 Speaker 1: their frequency, the duration of the pulses that the transducer 412 00:22:40,400 --> 00:22:43,119 Speaker 1: probe is creating. All right. That the precise frequency of 413 00:22:43,119 --> 00:22:46,280 Speaker 1: the waves greatly affects the resolution of the resulting image. 414 00:22:46,320 --> 00:22:48,600 Speaker 1: So this is really important, yes, it really is. It 415 00:22:48,640 --> 00:22:52,280 Speaker 1: Also it will determine how far the pulses can penetrate. 416 00:22:52,720 --> 00:22:54,639 Speaker 1: And on top of all those other things, you also 417 00:22:54,760 --> 00:22:56,919 Speaker 1: have a storage medium of some sort you want to 418 00:22:56,960 --> 00:23:00,160 Speaker 1: save this data. Obviously that might be on a disk, 419 00:23:00,560 --> 00:23:02,040 Speaker 1: or it might be on a you know, just a 420 00:23:02,080 --> 00:23:03,879 Speaker 1: hard drive or whatever. But it has to have some 421 00:23:03,960 --> 00:23:07,560 Speaker 1: source storage medium and also probably straight to the cloud 422 00:23:07,560 --> 00:23:10,800 Speaker 1: to the cloud, which is possible now, uh. And also 423 00:23:10,840 --> 00:23:13,600 Speaker 1: a printer so that you can print out an image, 424 00:23:13,920 --> 00:23:15,600 Speaker 1: especially in the case of babies. I think that it's 425 00:23:15,640 --> 00:23:18,480 Speaker 1: it's used more often in that case than um, yeah, 426 00:23:18,480 --> 00:23:21,479 Speaker 1: than than necessary, Like here's how your heart isn't working 427 00:23:22,040 --> 00:23:24,080 Speaker 1: that I mean, maybe if you want to collect that 428 00:23:24,119 --> 00:23:27,040 Speaker 1: sort of thing. Maybe you do, I'm not judging, but no, 429 00:23:27,400 --> 00:23:31,560 Speaker 1: that's exactly. My sister showed me a picture from her ultrasound, 430 00:23:31,680 --> 00:23:35,199 Speaker 1: so I got to see my niece or nephew early. 431 00:23:35,680 --> 00:23:39,960 Speaker 1: So that's kind of cool. Um, And now you know 432 00:23:40,040 --> 00:23:43,360 Speaker 1: the that's that's your basic parts of the ultrasonic device. 433 00:23:43,760 --> 00:23:46,560 Speaker 1: Keeping in mind that other you know, more advanced ones 434 00:23:46,640 --> 00:23:49,560 Speaker 1: may have other elements to them. But that's that's what 435 00:23:49,880 --> 00:23:52,199 Speaker 1: is kind of the bare requirements for you to have 436 00:23:52,200 --> 00:23:56,239 Speaker 1: an ultrasonic medical device. So the only other thing I 437 00:23:56,280 --> 00:23:58,880 Speaker 1: need to mention is that those those transducer probes also 438 00:23:58,920 --> 00:24:01,800 Speaker 1: tend to have some sort of absorbent material that will 439 00:24:01,840 --> 00:24:05,920 Speaker 1: allow it to absorb any echoes that would come from 440 00:24:05,920 --> 00:24:09,520 Speaker 1: the probe itself, because otherwise you would get right so, 441 00:24:09,560 --> 00:24:11,800 Speaker 1: because you don't want the crystal to just start vibrating 442 00:24:11,840 --> 00:24:13,800 Speaker 1: as soon as something bounces off the interior of the 443 00:24:13,800 --> 00:24:15,800 Speaker 1: probe and comes right back at the crystal. So that's 444 00:24:15,840 --> 00:24:18,800 Speaker 1: what the absorbent materials for. It's designed so that it'll 445 00:24:18,840 --> 00:24:22,000 Speaker 1: try and direct there's actually an acoustic lens that directs 446 00:24:22,000 --> 00:24:27,000 Speaker 1: the sound towards the patient's body. So that's the basics. 447 00:24:27,200 --> 00:24:30,000 Speaker 1: But you know that we mentioned already there's a little 448 00:24:30,040 --> 00:24:34,320 Speaker 1: bit more than just the basic display and imaging. There's 449 00:24:34,400 --> 00:24:38,600 Speaker 1: this whole three dimensional approach. UM. So first of all, 450 00:24:39,119 --> 00:24:45,360 Speaker 1: to get the unpleasant parts out. Not all ultrasound is noninvasive, right, UM, 451 00:24:45,400 --> 00:24:48,919 Speaker 1: it's not always external that there is recent controversy about 452 00:24:48,960 --> 00:24:53,320 Speaker 1: this UM in in abortion law. Oh I did not 453 00:24:53,440 --> 00:24:57,440 Speaker 1: know this, right, Well, it's it's the trans transmational ultrasound 454 00:24:58,119 --> 00:25:03,200 Speaker 1: in contests. So yeah, because because sometimes UM, for for 455 00:25:03,200 --> 00:25:06,520 Speaker 1: for many applications, you're looking at something in the body 456 00:25:06,760 --> 00:25:09,440 Speaker 1: that is not the most easily accessed from the outside. 457 00:25:09,880 --> 00:25:13,880 Speaker 1: So by by inserting a probe with an ultrasound uh 458 00:25:14,119 --> 00:25:17,040 Speaker 1: bit on the end into an orifice of one kind 459 00:25:17,160 --> 00:25:20,440 Speaker 1: or another, UM, you can determine many things about many 460 00:25:20,480 --> 00:25:23,719 Speaker 1: important internal organs. Yep. So this is uh you know, 461 00:25:23,960 --> 00:25:27,440 Speaker 1: it's probably a little less glamorous and comfortable than your 462 00:25:27,480 --> 00:25:30,719 Speaker 1: typical ultrasound, but it's very important and it's still in 463 00:25:30,760 --> 00:25:32,879 Speaker 1: the grand scheme of things. Like you know, it's hard 464 00:25:32,920 --> 00:25:35,560 Speaker 1: to say it's non invasive because you're talking about inserting 465 00:25:35,600 --> 00:25:41,280 Speaker 1: something into an orifice, but surgery, exploratory surgery way more invasive. 466 00:25:41,720 --> 00:25:46,800 Speaker 1: So it's you know, it's either way. There's some approaches 467 00:25:46,840 --> 00:25:51,200 Speaker 1: now where you can actually create three dimensional images of 468 00:25:51,480 --> 00:25:55,320 Speaker 1: stuff using ultrasound, and it's pretty much what you would expect. 469 00:25:55,320 --> 00:25:59,959 Speaker 1: You're you're you're moving the uh, the device, the transducer probe, 470 00:26:00,320 --> 00:26:03,520 Speaker 1: whether it's internal or external, and you're trying to get 471 00:26:03,600 --> 00:26:06,560 Speaker 1: multiple different views of whatever it is you're imaging. So 472 00:26:06,600 --> 00:26:08,119 Speaker 1: in the case of a baby, it would be the 473 00:26:08,160 --> 00:26:11,720 Speaker 1: baby and you might have to have the patient shift 474 00:26:11,760 --> 00:26:15,919 Speaker 1: around or in order to get angles. But yeah, the 475 00:26:15,960 --> 00:26:18,800 Speaker 1: computer takes in all that data and then creates a 476 00:26:18,840 --> 00:26:22,919 Speaker 1: three dimensional model of whatever it is it's that it's encountered, 477 00:26:23,280 --> 00:26:24,800 Speaker 1: and then you can look at that on the screen. 478 00:26:25,119 --> 00:26:28,280 Speaker 1: So this can be used in all sorts of medical approaches. 479 00:26:28,359 --> 00:26:30,960 Speaker 1: And uh. One of the things that relies upon is 480 00:26:31,000 --> 00:26:36,600 Speaker 1: another basic physical property that or universe sound waves, and 481 00:26:36,720 --> 00:26:39,280 Speaker 1: that we talked about before. Actually it's of any real waves, 482 00:26:39,520 --> 00:26:42,919 Speaker 1: the Doppler effect, right, the and that's the thing that 483 00:26:42,920 --> 00:26:47,399 Speaker 1: that describes how waves change shape when they encounter moving objects. Yeah, 484 00:26:47,520 --> 00:26:51,440 Speaker 1: so whether you whether the observer is moving or something 485 00:26:51,520 --> 00:26:54,960 Speaker 1: is moving toward an observer, this affects the way sound 486 00:26:55,560 --> 00:26:57,399 Speaker 1: sounds to us. That's the way we perceive sound. It 487 00:26:57,440 --> 00:27:00,600 Speaker 1: also affects the waves themselves. So let's say to that 488 00:27:00,760 --> 00:27:05,520 Speaker 1: Lauren is uh is screaming at a a single, constant, 489 00:27:05,920 --> 00:27:09,199 Speaker 1: constant pitch, perfect pitch. But she is just screaming, and 490 00:27:09,240 --> 00:27:12,040 Speaker 1: I'm running toward her, which is probably what's causing the screaming. 491 00:27:12,480 --> 00:27:14,840 Speaker 1: To me, the pitch is going to sound higher in 492 00:27:14,920 --> 00:27:17,439 Speaker 1: nature than someone who's standing right next to Lauren wondering 493 00:27:17,480 --> 00:27:20,200 Speaker 1: why she's screaming, And for the person who's running away 494 00:27:20,200 --> 00:27:23,240 Speaker 1: from Lauren, because that person knows when Lauren screams that's 495 00:27:23,240 --> 00:27:26,000 Speaker 1: bad news. It sounds like it's a lower pitch. Now. 496 00:27:26,040 --> 00:27:28,440 Speaker 1: That's because as I'm running towards Lauren, those waves of 497 00:27:28,520 --> 00:27:31,000 Speaker 1: sun waves coming towards me are actually compressed, right, uh 498 00:27:31,040 --> 00:27:32,960 Speaker 1: huh and uh. And as you would run away from 499 00:27:32,960 --> 00:27:36,720 Speaker 1: a noise, the sound waves lengthen and therefore deepen in pitch. Yeah, 500 00:27:36,800 --> 00:27:39,600 Speaker 1: So this Doppler effect, if you know what the Doppler 501 00:27:39,640 --> 00:27:42,040 Speaker 1: effect is, and you're able to measure it properly, you 502 00:27:42,040 --> 00:27:44,679 Speaker 1: can actually use that to your advantage to determine the 503 00:27:44,800 --> 00:27:48,080 Speaker 1: location of a moving object, whether it's moving towards you 504 00:27:48,160 --> 00:27:51,359 Speaker 1: or away. In this case, it's being used to help 505 00:27:51,440 --> 00:27:54,760 Speaker 1: create that three dimensional model. Hey there, it's Jonathan from 506 00:27:55,760 --> 00:27:58,200 Speaker 1: here to mention that we're going to take another quick 507 00:27:58,320 --> 00:28:10,320 Speaker 1: break about ultrasonic technology and we'll be right back. The 508 00:28:10,400 --> 00:28:13,480 Speaker 1: Doppler effect method is mainly used for very specific types 509 00:28:13,480 --> 00:28:16,480 Speaker 1: of imaging. Not all three D imaging is using this. 510 00:28:16,800 --> 00:28:20,159 Speaker 1: Mostly stuff where you want to measure something really subtle, 511 00:28:20,240 --> 00:28:24,160 Speaker 1: like blood flow through veins right in in in early 512 00:28:24,240 --> 00:28:28,240 Speaker 1: experiments with this and intravenous contrast agent would be introduced UM. 513 00:28:28,280 --> 00:28:30,960 Speaker 1: But then as the method was honed, we've we've become 514 00:28:31,040 --> 00:28:34,240 Speaker 1: able to detect movement of the blood cells themselves via 515 00:28:34,480 --> 00:28:38,160 Speaker 1: change in pitch. That's pretty amazing and it's really useful. 516 00:28:38,200 --> 00:28:42,200 Speaker 1: I mean it's for diseases that are largely invisible to us, right, 517 00:28:42,240 --> 00:28:45,160 Speaker 1: oh right, right, anything vascular, you know, finding clots or 518 00:28:45,160 --> 00:28:47,800 Speaker 1: monitoring flow and risky patients you know, like like after 519 00:28:47,840 --> 00:28:50,880 Speaker 1: a stroke or a transplanter surgery, um, as well as 520 00:28:50,920 --> 00:28:54,000 Speaker 1: finding cancerous tumors based on on the way that the 521 00:28:54,040 --> 00:28:57,680 Speaker 1: blood flow is being affected by the tumor. It's pretty phenomenal. 522 00:28:57,800 --> 00:29:01,880 Speaker 1: I mean, I really find the stuff truly amazing. So 523 00:29:02,160 --> 00:29:05,080 Speaker 1: it really became possible only with the digital revolution of 524 00:29:05,120 --> 00:29:08,000 Speaker 1: the nineteen eighties, like we were saying earlier. Um, because 525 00:29:08,040 --> 00:29:11,600 Speaker 1: you know, computers made it possible to to a more 526 00:29:11,600 --> 00:29:15,560 Speaker 1: precisely shape that ultrasonic beam as we as we mentioned, 527 00:29:15,640 --> 00:29:18,640 Speaker 1: and and be two to use multiple beams from multiple 528 00:29:18,680 --> 00:29:22,280 Speaker 1: angles simultaneously, which is that that multi courts action that 529 00:29:22,280 --> 00:29:24,560 Speaker 1: we were talking about. And you're talking about an enormous 530 00:29:24,560 --> 00:29:26,320 Speaker 1: amount of data, so it has to be a powerful 531 00:29:26,320 --> 00:29:29,400 Speaker 1: computer just to crunch all the numbers properly. So as 532 00:29:29,600 --> 00:29:32,960 Speaker 1: as those technologies have improved, so have the techniques. So 533 00:29:33,040 --> 00:29:34,920 Speaker 1: let's talk a little bit about what would be like 534 00:29:35,280 --> 00:29:38,480 Speaker 1: to go in and have to have an ultrasound procedure done. 535 00:29:38,480 --> 00:29:40,440 Speaker 1: Because a lot of people I think I've only seen 536 00:29:40,480 --> 00:29:43,719 Speaker 1: this on television shows or movies. Yeah, I if this 537 00:29:43,800 --> 00:29:46,360 Speaker 1: isn't complete, t M I UM, I have actually had 538 00:29:46,400 --> 00:29:48,640 Speaker 1: an ultrasound done. Um I. I go in for a 539 00:29:48,640 --> 00:29:52,640 Speaker 1: mammogram every year, and in addition to the mammogram, they 540 00:29:52,760 --> 00:29:56,040 Speaker 1: also do an ultrasound. All right, So so so tell 541 00:29:56,080 --> 00:29:57,720 Speaker 1: me if I got any of this wrong, because I 542 00:29:57,760 --> 00:29:59,800 Speaker 1: have not got in for an ultrasound. So, but I 543 00:30:00,040 --> 00:30:02,800 Speaker 1: based it off a great article called how Ultrasound Works 544 00:30:03,280 --> 00:30:07,520 Speaker 1: from how stuff Works dot com. Lug so typically what 545 00:30:07,600 --> 00:30:09,800 Speaker 1: you have as a patient comes in and removes his 546 00:30:09,880 --> 00:30:12,320 Speaker 1: or her clothing or whatever clothing would be in the 547 00:30:12,360 --> 00:30:15,880 Speaker 1: way specifically of the ultrasound equipment. Sure, because you don't 548 00:30:15,880 --> 00:30:18,440 Speaker 1: want to pick up the cloth. That wouldn't be useful, right, 549 00:30:18,440 --> 00:30:20,720 Speaker 1: That would that would be that would corrupt the signal, 550 00:30:20,840 --> 00:30:24,120 Speaker 1: So you would be that would make things more difficult. Also, 551 00:30:24,120 --> 00:30:26,560 Speaker 1: it could end up just even if it didn't directly 552 00:30:26,560 --> 00:30:29,520 Speaker 1: interrupt the signal, it could cause the probe to not 553 00:30:29,720 --> 00:30:33,680 Speaker 1: be flu flush against the skin, which could cause problems 554 00:30:34,160 --> 00:30:38,320 Speaker 1: right along those lines. Yeah, so we're getting into the jelly, 555 00:30:38,360 --> 00:30:41,400 Speaker 1: aren't we, the mineral oil based jelly. You might wonder 556 00:30:41,560 --> 00:30:44,560 Speaker 1: if you've ever seen essentially, but but if you've ever 557 00:30:44,600 --> 00:30:48,440 Speaker 1: seen any other movies where they they're spreading the jelly 558 00:30:48,960 --> 00:30:51,800 Speaker 1: over a patient's skin before using the ultrasound, you're wondering 559 00:30:51,800 --> 00:30:54,640 Speaker 1: why it's so that they can seal up any air 560 00:30:54,680 --> 00:30:57,680 Speaker 1: pockets that would have formed between the transducer probe and 561 00:30:57,720 --> 00:31:00,800 Speaker 1: the skin of the patient. Right Because, like we've said before, 562 00:31:01,240 --> 00:31:05,080 Speaker 1: since sound waves move differently through different media, when you've 563 00:31:05,120 --> 00:31:07,880 Speaker 1: got air in the way, that's going to cause some problems. Right, 564 00:31:07,920 --> 00:31:09,480 Speaker 1: So you don't want any air in the way. That's 565 00:31:09,480 --> 00:31:12,000 Speaker 1: why the jellies used, so in case you were ever wondering, 566 00:31:12,280 --> 00:31:15,320 Speaker 1: that's the purpose. Now at that point you have the 567 00:31:15,360 --> 00:31:19,200 Speaker 1: machine sending through those ultrasonic signals through the patient and 568 00:31:19,280 --> 00:31:23,040 Speaker 1: picking up the result through the probe through the patient exactly, 569 00:31:23,800 --> 00:31:26,360 Speaker 1: and then those sounds are reflecting off of the various 570 00:31:26,360 --> 00:31:29,200 Speaker 1: tissues within the patient coming back through the probe, sending 571 00:31:29,200 --> 00:31:32,080 Speaker 1: those signals back to the CPU, which then interprets them 572 00:31:32,320 --> 00:31:36,200 Speaker 1: and sends the signals to display which may or may 573 00:31:36,200 --> 00:31:37,960 Speaker 1: not be in view of the patient, depending upon what 574 00:31:38,040 --> 00:31:40,400 Speaker 1: the procedure is. Uh, and depending on you know, whether 575 00:31:40,480 --> 00:31:42,959 Speaker 1: the patient is is conscious or whether they want to 576 00:31:43,000 --> 00:31:45,680 Speaker 1: be looking at it UM and that the tech could 577 00:31:45,720 --> 00:31:49,800 Speaker 1: at that point mark areas for further investigation UM if needed. Yep. 578 00:31:49,920 --> 00:31:53,240 Speaker 1: And then that's information is usually recorded onto the storage 579 00:31:53,240 --> 00:31:55,480 Speaker 1: media so that it could be part of the patient's record. 580 00:31:56,080 --> 00:31:59,560 Speaker 1: And uh. Then that's the patient is pretty much allowed 581 00:31:59,600 --> 00:32:03,000 Speaker 1: to well, they're they're cleaned up the jelly. Yes, yes, 582 00:32:03,040 --> 00:32:05,320 Speaker 1: they give you a towel, so you clean yourself up 583 00:32:05,320 --> 00:32:07,480 Speaker 1: and then you put your clothes on and that part 584 00:32:07,480 --> 00:32:11,200 Speaker 1: of the examination is done. So it's pretty simple. In 585 00:32:11,240 --> 00:32:13,680 Speaker 1: the grand scheme of things. It's like it's like we said, 586 00:32:14,000 --> 00:32:18,920 Speaker 1: your basic ultrasonic uh investigation there is non invasive, so 587 00:32:19,000 --> 00:32:22,520 Speaker 1: that's a good thing. UM. Now, beyond the diagnoses, they're 588 00:32:22,520 --> 00:32:26,760 Speaker 1: actually looking at using ultrasonic technology to do some treatments. 589 00:32:26,840 --> 00:32:29,800 Speaker 1: So it's not just a a tool that's used to 590 00:32:30,440 --> 00:32:33,680 Speaker 1: check up on someone or get another look at something 591 00:32:33,680 --> 00:32:36,120 Speaker 1: that may or may not be a problem. In some cases, 592 00:32:36,160 --> 00:32:39,640 Speaker 1: they're talking about using it to to treat medical conditions, 593 00:32:39,680 --> 00:32:43,040 Speaker 1: often with nanotechnology. Although one of the coolest ones I 594 00:32:43,080 --> 00:32:46,320 Speaker 1: read about recently is another diagnostic tool, not a medical 595 00:32:46,320 --> 00:32:51,000 Speaker 1: treatment tool. It's a nano device that's an a nano 596 00:32:51,080 --> 00:32:55,920 Speaker 1: sized ultrasonic transducer that can actually image the interior of 597 00:32:55,960 --> 00:32:59,480 Speaker 1: a cell, individual living cell. That's awesome. Yeah, it's pretty 598 00:32:59,520 --> 00:33:02,560 Speaker 1: neat when you get that precise. That's pretty phenomenal. Uh. Yeah. 599 00:33:02,600 --> 00:33:05,160 Speaker 1: We we talked in a previous episode are are one 600 00:33:05,200 --> 00:33:08,520 Speaker 1: about gene therapy from December a little bit about one 601 00:33:08,560 --> 00:33:13,280 Speaker 1: of the other applications UM, which is using using ultrasound 602 00:33:13,280 --> 00:33:16,960 Speaker 1: waves to UM to push a little kind of nano 603 00:33:17,280 --> 00:33:21,360 Speaker 1: bubbles of of either medication or genes or whatever you 604 00:33:21,400 --> 00:33:24,040 Speaker 1: want to get inside a cell over to to where 605 00:33:24,080 --> 00:33:26,840 Speaker 1: you want them and then also using that ultrasound wave 606 00:33:26,920 --> 00:33:31,040 Speaker 1: to burst them appropriate. So that becomes a method of 607 00:33:31,120 --> 00:33:36,360 Speaker 1: delivery where you're actually maneuvering medication to some specific location. 608 00:33:36,680 --> 00:33:40,440 Speaker 1: Which that that's seems to be the big approach right now, 609 00:33:40,600 --> 00:33:44,960 Speaker 1: using ultrasonic or other technologies that are externally applied to 610 00:33:45,040 --> 00:33:47,880 Speaker 1: get nano based medicines to the right location, because we 611 00:33:47,920 --> 00:33:50,560 Speaker 1: haven't reached a point yet where we have little like 612 00:33:51,000 --> 00:33:53,840 Speaker 1: nano sized spaceships that can go straight to where they 613 00:33:53,840 --> 00:33:57,200 Speaker 1: need to go and then deliver the medical payload. So 614 00:33:57,840 --> 00:34:00,520 Speaker 1: a lot of the actual controls are not because we've 615 00:34:00,520 --> 00:34:04,240 Speaker 1: talked about nano robots before, this idea of a autonomous 616 00:34:04,280 --> 00:34:06,920 Speaker 1: or even semi just semi autonomous machine that can move 617 00:34:06,960 --> 00:34:09,040 Speaker 1: through the body. We are not there yet. But what 618 00:34:09,160 --> 00:34:12,879 Speaker 1: we can do is create nano sized particles that can 619 00:34:12,960 --> 00:34:17,920 Speaker 1: be manipulated externally through things like ultrasonic frequencies, which is 620 00:34:18,000 --> 00:34:20,879 Speaker 1: kind of cool. And you know, speaking of using ultrasonic 621 00:34:20,920 --> 00:34:24,560 Speaker 1: technology in fun ways, here's a fun way that ultrasonic 622 00:34:24,600 --> 00:34:28,080 Speaker 1: technology used to be used. So back in the seventies, Lauren, 623 00:34:28,120 --> 00:34:30,400 Speaker 1: there used to be an era called the nineteen seventies. 624 00:34:30,600 --> 00:34:32,680 Speaker 1: I do not remember that era because I was not 625 00:34:32,719 --> 00:34:35,400 Speaker 1: born yet, I was alive during this era. So in 626 00:34:35,400 --> 00:34:38,640 Speaker 1: the early nineteen seventies, a lot of televisions that were 627 00:34:38,680 --> 00:34:41,719 Speaker 1: coming out that had remote controls. Often not always, but 628 00:34:41,840 --> 00:34:45,440 Speaker 1: often would use ultrasonic frequencies to be the signals that 629 00:34:45,480 --> 00:34:47,239 Speaker 1: would send it to the television so that you could 630 00:34:47,239 --> 00:34:49,040 Speaker 1: turn it on or off, or the volume or changing 631 00:34:49,120 --> 00:34:52,680 Speaker 1: channel or whatever. So you would push a button and 632 00:34:52,760 --> 00:34:54,520 Speaker 1: often it was just on or off like that was 633 00:34:54,600 --> 00:34:56,840 Speaker 1: sometimes the only control that you had. Oh sure, I 634 00:34:56,840 --> 00:34:59,960 Speaker 1: mean we we didn't have channels in those days anyways, 635 00:34:59,680 --> 00:35:02,800 Speaker 1: as is usually about you know, between you'd have the 636 00:35:02,880 --> 00:35:05,920 Speaker 1: channels two through thirteen in the new UHF channel. Anyway, 637 00:35:05,960 --> 00:35:09,080 Speaker 1: you could turn the set on or off using this device. 638 00:35:09,120 --> 00:35:11,959 Speaker 1: It would send us ultrasonic frequency that you could not hear, 639 00:35:12,000 --> 00:35:13,919 Speaker 1: but it would be picked up by the television and 640 00:35:14,120 --> 00:35:16,600 Speaker 1: it would do whatever it was supposed to do. The 641 00:35:16,640 --> 00:35:19,279 Speaker 1: fun thing was that you could actually trigger this accidentally 642 00:35:19,400 --> 00:35:22,319 Speaker 1: if you were messing around with something else, like I 643 00:35:22,520 --> 00:35:26,359 Speaker 1: had uh an uncle who talked about how um he 644 00:35:26,480 --> 00:35:28,799 Speaker 1: thought it was amazing when he accidentally turned off the 645 00:35:28,800 --> 00:35:34,040 Speaker 1: television because he was carrying um a a like a 646 00:35:34,080 --> 00:35:37,000 Speaker 1: container of nuts. And bolts. He was going to do 647 00:35:37,040 --> 00:35:39,480 Speaker 1: a project, and he tripped and dropped them and they 648 00:35:39,560 --> 00:35:42,560 Speaker 1: hit the tiled floor and the and some of them 649 00:35:42,800 --> 00:35:45,520 Speaker 1: must have created this ultrasonic frequency that was the exact 650 00:35:45,520 --> 00:35:48,960 Speaker 1: same frequency that teld the TV to turn off. And 651 00:35:49,000 --> 00:35:51,000 Speaker 1: so he was wondering what was wrong with this television 652 00:35:51,360 --> 00:35:54,360 Speaker 1: And it wasn't until you know, some further experimentation that 653 00:35:54,400 --> 00:35:58,759 Speaker 1: he figured out, Oh so sound, Chris Pallette, the he 654 00:35:58,840 --> 00:36:01,200 Speaker 1: used to change the channel or turn this television off 655 00:36:01,239 --> 00:36:05,040 Speaker 1: by playing with a slinky. So um, yeah, fun times. 656 00:36:05,040 --> 00:36:09,000 Speaker 1: Now these days, kids, uh, they're using either infrared or 657 00:36:09,040 --> 00:36:12,160 Speaker 1: WiFi signals or some crazy thing like that. So you 658 00:36:12,160 --> 00:36:13,920 Speaker 1: can play with a slinky all day along in front 659 00:36:13,960 --> 00:36:15,719 Speaker 1: of your television and nothing's going to happen unless you 660 00:36:15,719 --> 00:36:20,080 Speaker 1: happen to have a infrared slinking or a mischievous sibling 661 00:36:20,160 --> 00:36:22,560 Speaker 1: with a remote control who is like, wow, look at 662 00:36:22,560 --> 00:36:26,080 Speaker 1: what you're doing, which could either be really funny or 663 00:36:26,640 --> 00:36:29,239 Speaker 1: you know, build you up for a terrible letdown later. 664 00:36:30,040 --> 00:36:33,719 Speaker 1: Ultrasound can also be used to keep your car windshield clean. 665 00:36:33,960 --> 00:36:39,360 Speaker 1: Say what seriously, the vibrations bounce, rain, debreathe like bugs, whatever, 666 00:36:39,719 --> 00:36:42,560 Speaker 1: right off of your of your windshield. Um. There's a 667 00:36:42,800 --> 00:36:45,799 Speaker 1: high end British car company called McLaren that is looking 668 00:36:45,840 --> 00:36:49,080 Speaker 1: to bring this tech to consumer cars. UM, assuming that 669 00:36:49,120 --> 00:36:52,000 Speaker 1: your consumer with you know, over two hundred thousand dollars. 670 00:36:52,480 --> 00:36:55,160 Speaker 1: That wraps up this classic episode of tech Stuff about 671 00:36:55,239 --> 00:37:00,040 Speaker 1: how ultrasound works. It's a fascinating technology, something that it 672 00:37:00,920 --> 00:37:03,560 Speaker 1: The more I looked into it, the more I was surprised. 673 00:37:03,800 --> 00:37:08,919 Speaker 1: This idea of using actual frequencies of sound in order 674 00:37:08,960 --> 00:37:13,239 Speaker 1: to learn more about stuff like what's going on inside us, 675 00:37:13,360 --> 00:37:17,480 Speaker 1: for example, beyond all the other applications. So it's a 676 00:37:17,520 --> 00:37:21,480 Speaker 1: phenomenal use of technology and physics, something that I truly 677 00:37:21,520 --> 00:37:25,840 Speaker 1: find fascinating. I hope you guys enjoyed this retrospective look 678 00:37:26,480 --> 00:37:29,959 Speaker 1: back at a historic tech Stuff episode. We'll be back 679 00:37:29,960 --> 00:37:32,960 Speaker 1: with new episodes next week. Can't wait to talk to 680 00:37:33,000 --> 00:37:35,720 Speaker 1: you then. If you guys have suggestions for future episodes 681 00:37:35,719 --> 00:37:38,600 Speaker 1: of tech Stuff, reach out on social media. You can 682 00:37:38,840 --> 00:37:41,279 Speaker 1: find us on both Facebook and Twitter. We have the 683 00:37:41,280 --> 00:37:44,880 Speaker 1: handle text stuff h s W and I'll talk to 684 00:37:44,920 --> 00:37:52,799 Speaker 1: you again really soon. Text Stuff is a production of 685 00:37:52,840 --> 00:37:55,920 Speaker 1: I Heeart Radio's How Stuff Works. For more podcasts from 686 00:37:55,920 --> 00:37:59,680 Speaker 1: I Heart Radio, visit the i Heart Radio app, Apple podcasts, 687 00:37:59,800 --> 00:38:01,800 Speaker 1: or ever you listen to your favorite shows.