WEBVTT - Rerun: How Ultrasound Works 0:00:04.240 --> 0:00:07.240 Welcome to tech Stuff, a production of I Heart Radios 0:00:07.320 --> 0:00:13.880 How Stuff Works. Hey there, and welcome to tech Stuff. 0:00:13.880 --> 0:00:16.320 I'm your host, Jonathan Strickland. I'm an executive producer with 0:00:16.360 --> 0:00:19.919 iHeart Radio and I love all things tech and guys, 0:00:20.160 --> 0:00:24.560 I have been traveling all over the United States as 0:00:24.640 --> 0:00:29.120 part of another podcast I do called The Restless Ones. 0:00:29.160 --> 0:00:31.440 If you've not checked that out, you should definitely give 0:00:31.480 --> 0:00:34.640 it a listen. I talked to chief technology officers, chief 0:00:34.640 --> 0:00:38.760 information officers, chief data officers, these really super smart folks 0:00:39.040 --> 0:00:43.400 who are shaping the way technology affects business, which means, 0:00:43.400 --> 0:00:47.760 in turn, it affects us. That show has been fantastic 0:00:47.880 --> 0:00:50.480 and a lot of work. It's also meant that I've 0:00:50.560 --> 0:00:54.280 been traveling a ton, so unfortunately, because of that, I 0:00:54.320 --> 0:00:57.680 didn't really have the time to fully research and write 0:00:57.720 --> 0:01:01.280 and prepare an episode ready to go today. So we're 0:01:01.280 --> 0:01:04.800 going to listen to a classic episode of tech Stuff instead, 0:01:05.360 --> 0:01:09.120 because I would rather do that than present a rushed, 0:01:10.480 --> 0:01:12.920 jerky kind of episode where you listen to it and 0:01:12.959 --> 0:01:15.720 think he didn't even put forth any effort. I always 0:01:15.720 --> 0:01:19.320 want to give you the best I can, so don't worry. 0:01:19.360 --> 0:01:21.679 New episodes of tech Stuff are right around the corner. 0:01:22.000 --> 0:01:24.440 I just didn't have it in me to get one 0:01:24.440 --> 0:01:26.679 out for today. So we're going to look back on 0:01:26.720 --> 0:01:31.800 a classic. This classic episode originally published on January two 0:01:31.840 --> 0:01:35.800 thousand fourteen, and it's called How Ultrasound Works, And I 0:01:35.800 --> 0:01:38.440 sat down with Lauren Vogelbaum, who was my co host 0:01:38.480 --> 0:01:42.400 at the time, to really talk about ultrasonic technology and 0:01:42.440 --> 0:01:44.920 what it's used for. I hope you guys enjoy it. 0:01:45.120 --> 0:01:48.240 Take a listen. As it turns out, humans have a 0:01:48.280 --> 0:01:51.760 certain range of sounds that a typical human can hear. 0:01:51.960 --> 0:01:54.840 Keeping in mind that different people can hear different ranges. 0:01:55.160 --> 0:01:57.480 Some may be able to hear a larger range, some 0:01:57.520 --> 0:02:01.120 people like me are starting to lose some of that range, 0:02:01.160 --> 0:02:03.559 and some people are better at lower higher ranges. Sure, 0:02:03.720 --> 0:02:07.040 um that the average is about twenty to twenty thousand 0:02:07.120 --> 0:02:10.360 hurts at the low and high end, right, So beyond 0:02:10.680 --> 0:02:15.040 twenty thousand hurts, like usually significantly beyond twenty thousand hurts 0:02:15.080 --> 0:02:18.760 at those higher frequencies. We call that ultrasonic. Well, you 0:02:18.760 --> 0:02:22.240 don't quite get into ultrasonicum right away. I mean, I mean, 0:02:22.280 --> 0:02:24.320 you know you've still got a good audible range. I mean, 0:02:24.320 --> 0:02:26.800 like Bluga whales, for example, can hear up to some 0:02:26.960 --> 0:02:29.440 like a hundred and twenty thousand hurts, but that is 0:02:29.440 --> 0:02:33.000 still not ultrasonic. Well, the true ultrasonic that we're looking at, 0:02:33.040 --> 0:02:36.520 for at least the the technology we'll be talking about 0:02:36.520 --> 0:02:39.520 today is in the one to one point five million 0:02:39.600 --> 0:02:43.680 hurts or mega hurts range. So that's where we're getting 0:02:43.680 --> 0:02:45.720 to a point where you know, animals are not detecting 0:02:45.760 --> 0:02:48.760 this kind of sounded a pitch that's much higher than 0:02:49.440 --> 0:02:52.079 a frequency that's much higher frequency and pitch I'm using 0:02:52.080 --> 0:02:56.680 almost interchangeably, which is little dis misleading, but you get 0:02:56.720 --> 0:03:00.440 what I'm saying. So this is a technology it's very 0:03:00.520 --> 0:03:04.600 much based in some part on something that actual animals 0:03:04.639 --> 0:03:08.480 are using. Some animals are using, right yep. And so 0:03:08.560 --> 0:03:11.280 that's something you probably heard about whenever you've you heard 0:03:11.280 --> 0:03:14.200 about things like bats or dolphins or whales. They all 0:03:14.320 --> 0:03:18.520 use echolocation as either a primary way of figuring out 0:03:18.600 --> 0:03:20.679 what their environments like in the case of bats, or 0:03:20.960 --> 0:03:23.560 you know, one of the many senses that they rely 0:03:23.720 --> 0:03:27.720 upon to explore their environments. Right. Humans also use this 0:03:27.800 --> 0:03:30.200 in the form of sonar or I mean really technically 0:03:30.280 --> 0:03:37.119 radar because we're talking about electromagnetic waves and waves, so yeah, 0:03:37.160 --> 0:03:40.240 but some are specifically is so that is like a 0:03:40.280 --> 0:03:43.320 sonic wave. So uh. In fact, sonar was a very 0:03:43.360 --> 0:03:47.280 important development in our history because radar, as it turns out, 0:03:47.720 --> 0:03:50.720 was not the best thing to use for underwater because 0:03:51.000 --> 0:03:53.160 you have a tinuation of those waves and you could 0:03:53.200 --> 0:03:55.160 never be really sure that the signals you were getting 0:03:55.160 --> 0:03:58.640 back were really accurate. Sonar is a much more accurate 0:03:58.800 --> 0:04:02.400 means of determining where something is underwater and whether it's 0:04:02.440 --> 0:04:04.880 moving towards you or moving away. We'll talk about more 0:04:04.960 --> 0:04:07.160 of that as we get further into this podcast, because 0:04:07.160 --> 0:04:10.760 some of those basic principles really determine some pretty cool 0:04:11.200 --> 0:04:14.680 uses of ultrasonic technology. Yeah, all of all of that 0:04:14.880 --> 0:04:19.400 history really builds upon the terrific baby viewing devices that 0:04:19.440 --> 0:04:22.200 we know and love today. Um, although that is certainly 0:04:22.200 --> 0:04:25.120 not the only use for ultrasound, as we will also 0:04:25.160 --> 0:04:27.080 get into. Yeah, I have a favorite one that I'll 0:04:27.080 --> 0:04:29.400 mention at the end. So, and it's one that I've 0:04:29.400 --> 0:04:31.840 talked about before on tech stuff. But that's okay, I 0:04:31.920 --> 0:04:34.800 don't mind repeating myself. All of you listeners out there 0:04:34.800 --> 0:04:36.920 who've been around for a while, you know this, so 0:04:37.480 --> 0:04:40.159 I appreciate that you humor me. I'm glad that you 0:04:40.160 --> 0:04:42.919 know this about yourself. John. Well, you know it's you 0:04:42.960 --> 0:04:45.960 reach a certain age, you come to some truths. So first, 0:04:46.040 --> 0:04:49.400 before I even dive into the history of ultrasonic technology, 0:04:49.440 --> 0:04:51.760 I have to give a shout out to Dr Jim Sung. 0:04:52.720 --> 0:04:55.960 He has a presentation online called the History of Ultrasound 0:04:55.960 --> 0:04:58.679 and Technological Advances that gave me a lot of insight 0:04:58.760 --> 0:05:03.840 into the the the discoveries that led to ultrasonic technology. 0:05:04.000 --> 0:05:06.520 And that's where I drew a lot of this information. 0:05:06.680 --> 0:05:11.320 So big up to him, really really good, clear, yes, 0:05:11.440 --> 0:05:14.240 very very simple kind of presentation. I did, you know, 0:05:14.279 --> 0:05:16.760 augment that with extra research, but it was a great 0:05:16.760 --> 0:05:22.120 starting point. So in sevento that's where we have a 0:05:22.160 --> 0:05:26.640 fellow by the name of Lazaro Spaladzani who was observing 0:05:26.640 --> 0:05:30.039 the behavior of bats, and as he was observing their behavior, 0:05:30.080 --> 0:05:33.760 he began to hypothesize what it was that allowed bats 0:05:33.800 --> 0:05:38.920 to navigate through really dark terrain, being able to avoid things, 0:05:38.920 --> 0:05:42.320 being able to zero in on prey. And as he 0:05:42.520 --> 0:05:45.000 thought about it, he came up with this hypothesis that 0:05:45.040 --> 0:05:48.320 perhaps they were making these very high pitched noises that 0:05:48.360 --> 0:05:51.240 were not necessarily within the range of human hearing. You 0:05:51.320 --> 0:05:53.120 might be able to hear a few squeaks now and then, 0:05:53.160 --> 0:05:56.640 but that's about it. But that they were also uh, 0:05:56.760 --> 0:06:00.400 reacting to the echoes of those noises to owne in 0:06:00.440 --> 0:06:03.159 on things or to avoid obstacles, a right to find 0:06:03.160 --> 0:06:06.200 out how far away or possibly even how big an 0:06:06.200 --> 0:06:09.360 obstacle or a predator or a piece of prey would 0:06:09.440 --> 0:06:11.560 be away from them. Yeah, because if if you're if 0:06:11.600 --> 0:06:14.560 you're hearing an echo come back, but it's not nearly 0:06:14.720 --> 0:06:17.400 as powerful as the sound you put out your your 0:06:18.200 --> 0:06:20.159 The result might be, oh, that thing is close, but 0:06:20.160 --> 0:06:23.040 it's also small. If you get a lot of signal back, 0:06:23.080 --> 0:06:25.040 you're like, Okay, there's something with a lot of surface 0:06:25.080 --> 0:06:27.560 area that's not too far away, and perhaps I don't 0:06:27.560 --> 0:06:30.760 want to go in that direction anymore. So he kind of, 0:06:31.400 --> 0:06:34.960 you know, was the one to propose this hypothesis of echolocation. 0:06:38.120 --> 0:06:41.440 Now that's again one of those basic principles that we 0:06:41.480 --> 0:06:44.920 would build upon to get to ultrasonic technology. In eighteen 0:06:44.960 --> 0:06:48.760 twenty six, you have Jean Daniel Calladon who was performing 0:06:48.760 --> 0:06:52.160 a series of experiments using a bell like a church bell. 0:06:52.320 --> 0:06:54.880 It was actually a church bell that he put underwater. 0:06:55.760 --> 0:06:59.360 He had a another little lever that had a striker 0:06:59.440 --> 0:07:01.920 on the end of it to strike the bell. So 0:07:02.480 --> 0:07:04.560 if you I like to imagine as one of those 0:07:04.560 --> 0:07:06.880 you remember then the cartoons, the boxing glove that's on 0:07:06.960 --> 0:07:10.040 the like accordion type thing stretches out. That's essentially what 0:07:10.120 --> 0:07:12.400 I imagined this to be. I'm sure that's exactly what 0:07:12.440 --> 0:07:15.480 it was, not according to the illustration I saw, but 0:07:15.520 --> 0:07:18.280 those things are never accurate. So anyway, there's this bell 0:07:18.360 --> 0:07:20.880 that's underneath the water, and he has a striker under 0:07:20.920 --> 0:07:24.680 the water as well. And then about ten miles away, 0:07:24.720 --> 0:07:27.520 according to the illustration, there was a second person in 0:07:27.560 --> 0:07:29.920 a boat who had a tube that went down into 0:07:29.920 --> 0:07:31.760 the water and they would essentially put their ear to 0:07:31.800 --> 0:07:34.560 the tube to listen in like an ear earpiece and earphone, yes, 0:07:34.680 --> 0:07:37.440 so that they could you would amplify any sounds they 0:07:37.480 --> 0:07:39.520 could maybe you know, their and their job was to 0:07:39.640 --> 0:07:45.360 listen for the tone of the bell, and so uh 0:07:45.560 --> 0:07:48.760 he would call it on strikes the bell. The person 0:07:48.800 --> 0:07:52.400 in the other boat writes down exactly when they heard 0:07:52.440 --> 0:07:55.640 the tone, and the idea here was actually for call 0:07:55.680 --> 0:07:59.120 it on to show that the sound would travel at 0:07:59.160 --> 0:08:02.040 a different speed through water that it did through the air. 0:08:02.440 --> 0:08:06.480 This was just to demonstrate hypothesis that sound traveled at 0:08:06.520 --> 0:08:09.440 different speeds through different media, something that we know to 0:08:09.480 --> 0:08:12.600 be true now, right, And and in fact, it travels 0:08:12.600 --> 0:08:14.840 faster in water than it does the air. Yeah, So 0:08:14.960 --> 0:08:18.800 depending upon how tightly packed the molecules are and whatever 0:08:18.840 --> 0:08:21.120 it is that you're looking at, sound can travel much 0:08:21.160 --> 0:08:23.880 more quickly through some media than others. And it's because 0:08:23.920 --> 0:08:25.920 it's a very it's a physical media. It's not an 0:08:25.960 --> 0:08:29.960 electromagnetic it's actual physical molecules banging into each other. So 0:08:30.000 --> 0:08:32.560 if they're more tightly packed, they banging into each other 0:08:32.679 --> 0:08:35.680 much more quickly. So in that case he was able 0:08:35.720 --> 0:08:38.400 to show that it indeed does travel at different speeds. 0:08:38.760 --> 0:08:41.480 Knowing that it travels at different speeds is also very 0:08:41.520 --> 0:08:44.720 important for the very basics of ultrasonic technology, which is 0:08:44.720 --> 0:08:48.520 why we're talking about in the first place. So the 0:08:48.720 --> 0:08:54.319 eighty six, our next date is eighteen eighty. We're just 0:08:54.320 --> 0:08:59.000 just scorching through history along. This is where Pierre and 0:08:59.160 --> 0:09:02.840 Jacques Curi discover the piece of electric effect, which we 0:09:02.880 --> 0:09:05.600 have talked about quite a few times on tech stuff. 0:09:05.720 --> 0:09:07.960 All right, this is this winds up being useful in 0:09:07.960 --> 0:09:11.560 many applications. But so what is it? Okay, So certain 0:09:11.600 --> 0:09:16.079 types of material, like for example, quartz crystals have this 0:09:16.080 --> 0:09:20.680 this particular this particular feature where if you were to 0:09:20.760 --> 0:09:24.960 apply an electric charge to this material, it would vibrate, 0:09:25.360 --> 0:09:29.320 or if you apply a mechanical stress to this object, 0:09:29.400 --> 0:09:32.320 it will then create an electrical charge. It's this weird 0:09:33.000 --> 0:09:37.920 reaction of electricity and actual kinetic movement energy that you're 0:09:37.920 --> 0:09:41.000 gonna see between the two things. And in the case 0:09:41.040 --> 0:09:44.600 of quartz crystals, it's really really regular. You know, if 0:09:44.600 --> 0:09:47.080 you know the properties of the quartz crystal, you are 0:09:47.200 --> 0:09:49.200 good to go. You know that at a certain charge, 0:09:49.200 --> 0:09:52.280 it's always going to give off the same kind of vibration. 0:09:52.679 --> 0:09:54.880 So that's why quartz crystals are used in a lot 0:09:54.920 --> 0:09:57.720 of watches. It's actually the thing that helps keep time 0:09:58.120 --> 0:10:00.480 right right. It creates the movement in courts watch because 0:10:00.480 --> 0:10:03.600 it is so regular or so um, so predictable. Um. 0:10:03.640 --> 0:10:06.959 It also can it's used to create a spark in 0:10:07.000 --> 0:10:08.920 the kind of gas lighters that are used for for 0:10:08.960 --> 0:10:12.120 candles or cigarettes, and also um, you know, it's being 0:10:12.160 --> 0:10:14.880 talked about for energy harvesting kind of materials that are 0:10:14.960 --> 0:10:17.560 being that are in research today right and now. In 0:10:17.600 --> 0:10:21.640 the case of ultrasonic technology, this is important because the 0:10:21.760 --> 0:10:25.880 quartz crystals are the things in most ultrasonic transducers that 0:10:25.920 --> 0:10:30.080 are creating the vibrations that themselves are these high frequency 0:10:30.320 --> 0:10:33.400 sound waves. And with something as simple as electricity or 0:10:33.440 --> 0:10:37.640 relatively simple or you know, relatively technologically um possible to 0:10:37.760 --> 0:10:41.760 put into an instrument. So also they're very important for 0:10:41.800 --> 0:10:44.240 picking the signals back up as its out. Well, we'll 0:10:44.280 --> 0:10:45.880 talk more about that when we get into the actual 0:10:45.880 --> 0:10:47.880 how it works stuff, but all of this, you know, 0:10:48.000 --> 0:10:51.720 again plays into it. So nineteen fift you have Paul 0:10:51.800 --> 0:10:55.920 Langevin who invents the hydrophone, which again very important this 0:10:56.040 --> 0:10:58.600 in this case, it's essentially a microphone that can go 0:10:58.880 --> 0:11:02.560 into the water, uh and it relies on the piece 0:11:02.559 --> 0:11:06.240 of electric effect in order to pick up signals in 0:11:06.280 --> 0:11:08.960 the water. What's doing is it's detecting changes in pressure, 0:11:09.360 --> 0:11:11.040 which are you know, that's what you know, the sound 0:11:11.080 --> 0:11:13.440 that's moving through the water is changing the actual pressure 0:11:13.800 --> 0:11:17.520 that the this hydrophone detects. The pressure changes affect the 0:11:17.600 --> 0:11:20.920 quartz crystals inside the hydrophone, which then generates the electricity, 0:11:21.000 --> 0:11:23.680 which then goes to another device that again in turns 0:11:24.480 --> 0:11:27.360 and figure out yeah, or even converted back over into 0:11:27.440 --> 0:11:30.400 sound so that you can listen to what's going on underneath. 0:11:30.920 --> 0:11:34.920 He got the the inspiration to really work on this 0:11:35.000 --> 0:11:38.240 after something that happened in nineteen twelve, which was when 0:11:38.440 --> 0:11:40.599 Leonardo DiCaprio sank to the bombo of the ocean and 0:11:40.640 --> 0:11:44.720 froze to death, or more historically speaking, is when the 0:11:44.760 --> 0:11:48.120 Titanic sank. I thought, that's what I just said. Well, um, 0:11:48.360 --> 0:11:51.440 but yeah, yeah. The hydrophone was originally created in order 0:11:51.520 --> 0:11:55.280 to help detect icebergs and submarines in other large World 0:11:55.320 --> 0:11:57.720 War One and World War Two. It was really important. 0:11:57.920 --> 0:11:59.880 World War two is also really when Sonar I came 0:12:00.080 --> 0:12:02.880 to play. But before sonar it was really just listening 0:12:03.000 --> 0:12:05.679 for stuff that you think that should not be there 0:12:05.720 --> 0:12:08.480 and we need to get out of here. So ninety 0:12:08.559 --> 0:12:12.560 seven or right thereabouts, a man named Carl Dissick, who 0:12:12.600 --> 0:12:15.000 was a doctor with the University of Vienna, begins to 0:12:15.480 --> 0:12:20.600 work on using ultrasound as a means of diagnosing brain tumors. Now, 0:12:20.679 --> 0:12:24.400 at this time, ultrasonic technology was mostly being used in 0:12:24.440 --> 0:12:29.200 those those non applications exactly. But he thought, you know, 0:12:29.760 --> 0:12:32.400 this could probably tell you more about what's going on 0:12:32.440 --> 0:12:34.880 inside a person. The human brain is filled with water. 0:12:35.120 --> 0:12:37.520 Yeah I can, I mean essentially, yeah, I can totally 0:12:37.559 --> 0:12:39.400 figure out what's going on. Maybe if there's a tumor 0:12:39.480 --> 0:12:42.120 or something, I can detect it. Now, his approach is 0:12:42.280 --> 0:12:45.480 very different from what is used today. What we use 0:12:45.559 --> 0:12:50.520 today is a reflective technique where you send a signal 0:12:50.600 --> 0:12:54.720 through a person. It reflects off of various various stuff, 0:12:54.720 --> 0:12:57.160 will go into more detail in the second half and 0:12:57.280 --> 0:13:01.640 bounces back and then read out by a receiver in 0:13:01.679 --> 0:13:04.240 the instrument right exactly, and then a computer kind of 0:13:04.480 --> 0:13:06.839 puts all that data together to make it meaningful to you. 0:13:07.320 --> 0:13:11.439 He was actually thinking about setting up two different ultrasonic transducers, 0:13:11.440 --> 0:13:14.800 one on either side of your noggat and zapping straight 0:13:14.800 --> 0:13:17.319 through the brain. So he had a receiver on both 0:13:17.360 --> 0:13:20.160 sides and a transceiver on both sides, so you're sending 0:13:20.160 --> 0:13:25.320 signals simultaneously. And the idea was that he thought that 0:13:25.440 --> 0:13:28.120 the reflection would never be reliable enough for you to 0:13:28.120 --> 0:13:29.920 be able to have any sort of precise idea what's 0:13:29.920 --> 0:13:34.559 going on. Other people said that his particular techniques were 0:13:34.679 --> 0:13:38.319 um muddy, like it was creating too much noise because 0:13:38.320 --> 0:13:40.679 you had these two different sources going at it, and 0:13:40.720 --> 0:13:44.640 so signals right and right, some of it's reflected back, 0:13:44.720 --> 0:13:47.640 some of it keeps going through, and so there are 0:13:47.640 --> 0:13:50.079 people who said that the information you would get back 0:13:50.120 --> 0:13:55.200 from this particular method, uh was you know, not terribly reliable. 0:13:55.720 --> 0:13:58.960 Dust because it turns out would go on to be 0:14:00.080 --> 0:14:04.120 drafted into the Luftwaffe during World War Two and actually 0:14:04.160 --> 0:14:08.880 would become a doctor treating head wounds for German soldiers. Um. 0:14:08.960 --> 0:14:11.640 He would continue after the war to really be a 0:14:11.679 --> 0:14:16.120 proponent of ultrasonic technology being used in the medical field. However, 0:14:16.160 --> 0:14:19.200 he continued to say that he wanted the transmission effect 0:14:19.280 --> 0:14:22.880 was more important than the reflective effect. Uh. And ultimately 0:14:23.520 --> 0:14:26.960 some researchers at M I I T determined that the method 0:14:27.040 --> 0:14:29.760 that Dosik was using was creating all this noise I 0:14:29.800 --> 0:14:32.840 was talking about before, and it really wasn't reliable. So 0:14:33.600 --> 0:14:37.720 history would end up switching gears, going the different direction 0:14:38.240 --> 0:14:41.320 and still using ultrasonic technology, but in a different implementation 0:14:41.360 --> 0:14:44.480 than he did. Yeah, and and absolutely that pioneering kind 0:14:44.520 --> 0:14:46.760 of going like hey, human bodies are fill of liquid 0:14:46.880 --> 0:14:49.480 we can use this technology to look at them too. Yeah, 0:14:49.560 --> 0:14:52.720 it's pretty it's sound. It's not like it's ionizing radiation. 0:14:52.760 --> 0:14:55.400 It's not something that's gonna cause you some form of harm. 0:14:55.680 --> 0:14:58.840 It's it's a physical that. There are a couple of 0:14:58.880 --> 0:15:02.320 concerns that I've heard here and there about the ultrasonic 0:15:02.320 --> 0:15:05.520 waves interfering or or creating small bubbles or or various 0:15:05.560 --> 0:15:08.560 things like right, right, But it's not an ionizing radiation, 0:15:08.840 --> 0:15:11.360 which is the main difference between that and other imaging. 0:15:11.480 --> 0:15:15.400 Definitely better than X rays. Yes, uh so that's when 0:15:15.480 --> 0:15:18.560 Dr George Ludwig writes a paper describing the use of 0:15:18.560 --> 0:15:21.680 an ultrasonic device to diagnose skull stones, and in nineteen 0:15:21.720 --> 0:15:25.160 fifty one, doctors Wild and Neil began publishing studies on 0:15:25.240 --> 0:15:29.280 ultrasonic characteristics of benign versus malignant breast tumors, not intended 0:15:29.280 --> 0:15:31.840 as a detection tool actually, but rather as a diagnostic 0:15:31.880 --> 0:15:34.160 tool once a tumor had been found, so, in other words, 0:15:34.200 --> 0:15:36.440 to determine whether or not this tumor in fact is 0:15:36.480 --> 0:15:39.240 benign or malignant. Right. So, yeah, so this is after 0:15:39.360 --> 0:15:41.680 we've already established it there is a presence of a 0:15:41.680 --> 0:15:45.920 tumor nifty eight we got Dr Ian Donald, who I 0:15:46.000 --> 0:15:50.320 love his technical title, which was Professor of Midwifery at 0:15:50.320 --> 0:15:53.800 the University of Glasgow. Yeah, he pioneered O B G 0:15:54.040 --> 0:15:55.960 Y and ultrasound, which is what most of us think 0:15:56.000 --> 0:15:58.600 about when we think of ultrasound devices in medical fields. 0:15:58.640 --> 0:16:01.280 I think it's it's for the common lay person. That 0:16:01.400 --> 0:16:03.640 is the application in which we have seen and heard 0:16:03.640 --> 0:16:05.840 it used. Yeah, and it's it's certainly one that oh no, 0:16:06.000 --> 0:16:08.440 that was kind of sorry, didn't do it this time. 0:16:08.800 --> 0:16:11.760 So it's it's certainly the thing that we see all 0:16:11.760 --> 0:16:14.480 the time in movies and television. And you know, it's 0:16:14.520 --> 0:16:17.600 the sty it's that's the typical was in the hospital. 0:16:18.120 --> 0:16:19.560 This is the picture of the baby. It's also I 0:16:19.560 --> 0:16:21.680 mean I just recently saw one because my sisters have 0:16:22.240 --> 0:16:24.920 a lot of people are born it turns out, Yeah, 0:16:24.960 --> 0:16:28.120 and it's a very popular way of of imaging before. 0:16:28.800 --> 0:16:30.480 I mean, you know, especially and we'll we'll go into 0:16:30.520 --> 0:16:31.880 this a little bit more later, but you know, it's 0:16:31.920 --> 0:16:33.880 it's really terrific for figuring out what's going on with 0:16:33.920 --> 0:16:36.000 a baby without doing any kind of harm to the 0:16:36.000 --> 0:16:38.120 mother or the baby, right, right, You don't want anything 0:16:38.120 --> 0:16:42.880 that could potentially disrupt development or cause other complications. Uh. 0:16:42.920 --> 0:16:46.040 So skipping way ahead because obviously ultrasound by this time 0:16:46.040 --> 0:16:48.800 had been an established medical technology. It's also was used 0:16:48.800 --> 0:16:52.240 in other applications. Will talk a little bit about that later. 0:16:52.680 --> 0:16:55.640 Uh skipping way ahead, we get to a point where 0:16:55.720 --> 0:16:59.680 Daniel Liechtenstein pioneers a point of care long ultrasound in 0:16:59.720 --> 0:17:02.360 the ice see you and says that ultrasound is the 0:17:02.440 --> 0:17:07.040 real stethoscope. At this stage, we're talking about precision where uh, 0:17:07.119 --> 0:17:10.120 it was much greater than anything that desn't ever managed. 0:17:10.119 --> 0:17:12.160 It was something where you could actually get a really 0:17:12.200 --> 0:17:15.640 accurate look and in some cases a three dimensional look 0:17:16.040 --> 0:17:18.200 at what's going on inside a person without it being 0:17:18.240 --> 0:17:22.080 invasive or terribly invasive, because there are some there are 0:17:22.119 --> 0:17:24.800 some exceptions we'll talk about, yes, But but this is 0:17:24.800 --> 0:17:28.240 mostly thanks to advancements in computers in the digitization of 0:17:28.320 --> 0:17:31.560 ultrasound exactly. So we're gonna talk a lot more about 0:17:31.600 --> 0:17:34.600 how this actually works, what's really going on with this stuff. 0:17:34.600 --> 0:17:36.920 But before we get into that, let's take a quick 0:17:36.960 --> 0:17:47.440 break to thank our sponsor. Alright, so we're back. Let's 0:17:47.480 --> 0:17:51.639 talk about how ultrasonic technology actually works. You have to 0:17:51.680 --> 0:17:54.919 be able to have something that creates an ultrasonic signal, 0:17:55.240 --> 0:17:56.679 and it has to be able to pick up that 0:17:56.800 --> 0:17:58.960 ultrasonic signal, and then it has to be able to 0:17:59.000 --> 0:18:03.280 interpret the signal. So these are these are some important 0:18:03.480 --> 0:18:06.920 elements that again would only have been possible due to 0:18:06.960 --> 0:18:08.679 the work of the people we talked about in the 0:18:08.720 --> 0:18:14.240 first half. So, uh, your basic, your basic approach here. 0:18:14.320 --> 0:18:16.600 This is before I get into any of the actual 0:18:17.280 --> 0:18:20.359 Here's the technical stuff that's going on. Is you've got 0:18:20.400 --> 0:18:24.040 a device that sends the signal out which then encounters 0:18:24.080 --> 0:18:28.440 the various tissue barriers in a person's body for ultrasonic 0:18:28.480 --> 0:18:33.480 medical imaging anyway. So, UH, as it encounters these barriers, 0:18:33.600 --> 0:18:38.880 some of those ultrasonic waves are gonna bounce back. So 0:18:39.359 --> 0:18:41.840 the machine starts to collect the data of the material 0:18:41.840 --> 0:18:45.040 of the waves that bounce back, the intensity of those waves, 0:18:45.080 --> 0:18:46.919 and the length of time it took for them to 0:18:46.960 --> 0:18:49.920 go out and bounce back, give the idea of things 0:18:49.920 --> 0:18:52.360 like the depth and the nature of the tissue itself. 0:18:52.840 --> 0:18:56.119 The uh, some of the waves will continue to penetrate 0:18:56.160 --> 0:18:59.000 into the patient's body and then bounce off other boundaries. 0:18:59.160 --> 0:19:02.240 So these boundaries are things like boundaries between liquids and 0:19:02.280 --> 0:19:05.600 soft tissue, or soft tissue and hard tissue, so and 0:19:05.720 --> 0:19:09.520 oregon and bones, that kind of thing. And as the 0:19:09.560 --> 0:19:12.720 waves go and bounce back, we start to be able 0:19:12.720 --> 0:19:14.800 to look at that data and determine what kind of 0:19:14.800 --> 0:19:18.480 tissue it was going through, because because we know that 0:19:18.480 --> 0:19:21.240 that these sound waves travel at different speeds through different 0:19:21.240 --> 0:19:25.280 types of Yeah, exactly, So by knowing you know, if 0:19:25.320 --> 0:19:27.320 you know that sound travels at such and such a 0:19:27.359 --> 0:19:30.240 speed as it goes through bone, which we know, we 0:19:30.280 --> 0:19:31.800 do know, I mean, I don't know, if I don't, 0:19:32.680 --> 0:19:35.920 we don't personally know. But human kind knows people smarter 0:19:36.040 --> 0:19:38.320 than you know. You have that thing where you just 0:19:38.400 --> 0:19:40.600 trust that people smarter than you are working on the problem. 0:19:40.640 --> 0:19:43.120 In this case, it's true, so not so much working 0:19:43.160 --> 0:19:46.639 as much as have already completely figured out there charts 0:19:46.720 --> 0:19:50.520 that you can look at. So the computer, which we'll 0:19:50.520 --> 0:19:52.639 talk about in the second, takes all this data in 0:19:52.720 --> 0:19:55.640 and is able to analyze it and determine which waves 0:19:55.640 --> 0:19:58.280 were the ones that passed through liquid, which ones were 0:19:58.280 --> 0:20:00.280 the ones that passed through soft tissue, which ones passed 0:20:00.280 --> 0:20:04.040 through hard tissue, and then adding all that information together 0:20:04.160 --> 0:20:07.480 is able to create a picture that's been displayed on 0:20:07.560 --> 0:20:10.480 a display. It sends the information to a display so 0:20:10.480 --> 0:20:14.560 that you get essentially a virtual representation of whatever it 0:20:14.680 --> 0:20:18.320 is that's there. Typically it's two dimensional, so we'll talk 0:20:18.359 --> 0:20:23.760 a bit about three D. Uh ultra relatively new development, 0:20:24.040 --> 0:20:28.240 but it is certainly possible. But your traditional ultrasonic images 0:20:28.280 --> 0:20:30.320 are two dimensional. So it's kind of like a a 0:20:30.440 --> 0:20:33.199 side view or top down view, depending upon the angle 0:20:33.320 --> 0:20:38.359 that's being used and what you are specifically trying to image, right, So, uh, 0:20:38.400 --> 0:20:41.960 it's a really cool approach. Now. The parts that are 0:20:42.160 --> 0:20:45.720 on an ultrasonic machine include the transducer probra, which we've 0:20:45.720 --> 0:20:47.960 talked a little bit about. Right. This is the device 0:20:48.000 --> 0:20:50.359 that is sending and receiving the signals. That's got at 0:20:50.440 --> 0:20:53.080 least one quartz crystal in it. It may have multiple 0:20:53.160 --> 0:20:55.000 quartz crystals in it, and in fact, if it does 0:20:55.040 --> 0:20:59.440 have multiple quarts crystals, you can time the different crystals 0:20:59.480 --> 0:21:02.800 to file air at you send charges to them at 0:21:02.800 --> 0:21:05.879 different times because each one has its own independent circuit, 0:21:06.560 --> 0:21:10.680 and that allows you to quote unquote steer the ultrasonic 0:21:10.760 --> 0:21:13.200 beam and be able to get a lot more precision 0:21:13.320 --> 0:21:16.840 about what's going on. UM. But even if it only 0:21:16.840 --> 0:21:19.119 has one crystal, I can still send and then receive. 0:21:19.200 --> 0:21:21.760 So what's happening is you send an electrical charge to 0:21:21.800 --> 0:21:25.000 the crystal. The crystal vibrates at this incredibly high frequency, 0:21:25.040 --> 0:21:28.400 which creates this ultrasonic sound like one to one point 0:21:28.400 --> 0:21:32.879 five mega hurts. And you're talking about possibly millions of 0:21:32.920 --> 0:21:35.920 these and a millions of pulses in a single second. 0:21:36.320 --> 0:21:38.800 They go into the body and start to bounce off 0:21:38.840 --> 0:21:42.639 of stuff. When the sounds bounce back to the transducer probe, 0:21:43.040 --> 0:21:46.359 they hit the quartz crystal, which causes the quartz crystal 0:21:46.440 --> 0:21:50.160 to vibrate, which then causes the electric charge to emanate. 0:21:50.240 --> 0:21:52.399 So because of that piece of electric effect, it works 0:21:52.400 --> 0:21:56.320 both ways. The device picks up the electric charges and 0:21:56.400 --> 0:21:58.960 that's what it's able to use to interpret the actual 0:21:59.080 --> 0:22:03.160 data that is gathered and sent onto the computer. So 0:22:03.200 --> 0:22:06.359