04 History of Ultrasound: Lecture by Dr. Eric Blackwell on History and Physics

Summary

This script recounts the evolution of ultrasound technology from its inception in 1949 for battlefield use to its modern applications in medical imaging. It highlights the transition from rudimentary oscilloscope images to advanced 3D imaging, showcasing remarkable advancements in resolution and portability. The speaker reflects on the pioneers who shaped the field and the current capabilities of ultrasound, including its use in detecting fetal abnormalities and monitoring patient conditions in real-time.

Takeaways

• 🕰️ The first known article on the use of ultrasound in humans was published in 1949 by Dr. George Ludwig, who was exploring its potential to detect foreign bodies in battlefield injuries.
• 🔍 Early ultrasound technology was primarily used to measure distances to structures within the body, with images appearing as spikes on an oscilloscope rather than the detailed images we have today.
• 🌐 The evolution of ultrasound has been remarkable, from bistable black and white displays to current high-resolution 3D capabilities that allow for detailed examination of soft tissues and bone.
• 👶 Ultrasound technology has advanced to the point where it can capture detailed images of early pregnancies, including the ability to see the yolk sac, amniotic fluid, and placental tissue.
• ❤️ The resolution of modern ultrasound equipment is so high that it can detect sub-millimeter defects, such as a ventricular septal defect in a fetal heart.
• 😀 The speaker humorously notes the ability to see fetal emotions in 3D ultrasound, showcasing the depth of detail possible with current technology.
• 🙏 The speaker acknowledges the contributions of pioneers in the field, such as Dr. Bill McKinney, who was instrumental in advancing the use of ultrasound in medicine.
• 🎥 The script mentions the transition from military surplus sonar equipment to medical ultrasound devices, highlighting the repurposed technology's role in early ultrasound development.
• 📺 The evolution from contact B scanners to real-time moving pictures represents a significant technological leap in ultrasound imaging.
• 💻 The development of portable and handheld ultrasound devices, resembling laptop computers, has made ultrasound more accessible and practical for point-of-care use.
• 🔌 The latest advancements include cordless ultrasound transducers, which offer greater flexibility and convenience, especially in sterile environments like surgery.

Q & A

What was the first known application of ultrasound in humans?

The first known application of ultrasound in humans was in 1949 by Dr. George Ludwig from the Department of Defense, who used it to look for foreign bodies like glass or wood in battlefield injuries that didn't show up on X-rays.

Why was the early ultrasound not effective for detecting foreign bodies in the battlefield?

The early ultrasound was not effective for detecting foreign bodies because ultrasound waves cannot penetrate certain materials like glass or wood, which are not radio opaque.

How did the ultrasound technology evolve from its first use to the 1970s?

Ultrasound technology evolved from the initial use in 1949 to the 1970s with the development of images that were displayed on oscilloscopes, which were used to measure distances to structures within the body.

What was the limitation of early ultrasound images in the 1970s?

The limitation of early ultrasound images in the 1970s was that they were displayed on oscilloscopes with bistable images, either on or off, with no shades of gray, and required a Polaroid camera to capture a permanent picture.

How has the ultrasound technology advanced in terms of image quality and capabilities?

Ultrasound technology has advanced significantly with the introduction of 3D imaging, color Doppler for blood flow visualization, and high-resolution images that can detect minute details such as sub-millimeter defects in a fetal heart.

What is the significance of the 'point of care' concept in the context of early ultrasound applications?

The 'point of care' concept refers to the ability to perform medical examinations at the patient's bedside or in the field. The first application of ultrasound was essentially a point of care tool, although it required plugging into an AC power line and was not portable.

What was the role of Dr. Bill McKinney in the development of ultrasound technology?

Dr. Bill McKinney was a neurologist who became the president of the American Institute of Ultrasound in Medicine. He was instrumental in promoting the use of ultrasound and brought many people into the field, including the speaker of the script.

How did the surplus of sonar equipment from World War II contribute to the development of ultrasound technology?

The surplus of sonar equipment from World War II provided a foundation for researchers to experiment with ultrasound technology. The equipment was repurposed for medical use, leading to the development of early ultrasound machines.

What was the 'water path' concept in early ultrasound scans?

The 'water path' concept involved using a plastic bag filled with water to create a medium for the ultrasound waves to travel through. This was necessary because the technology required a water-based environment for the ultrasound waves to be effective.

How did the transition from B-mode scanners to contact B scanners impact the practicality of ultrasound technology?

The transition from B-mode scanners, which required a water path, to contact B scanners that made direct contact with the skin, made the technology more practical for day-to-day patient care by eliminating the need for a water-filled medium and improving image quality.

What are the benefits of the recent advancements in portable ultrasound devices?

Recent advancements in portable ultrasound devices, such as the development of handheld units and wireless transducers, have made ultrasound technology more accessible and convenient for various medical applications, including point-of-care diagnostics and surgical assistance.

Outlines

00:00

🌐 The Dawn of Ultrasound in Medicine

The script begins by recounting the early history of ultrasound technology, starting from its first known medical application in 1949. Dr. George Ludwig from the Department of Defense was the pioneer, attempting to use ultrasound to detect foreign bodies in battlefield injuries. Although unsuccessful for that purpose, this marked the inception of point-of-care ultrasound. The speaker then reflects on their own experience with ultrasound in 1974, highlighting the evolution from rudimentary spike images on an oscilloscope to modern 3D imaging capabilities. The paragraph also showcases the remarkable advancements in ultrasound imaging, from basic distance measurements to detailed fetal imaging, including the ability to detect minute abnormalities such as a ventricular septal defect.

05:03

🛸 Evolution of Sonar and Early Ultrasound Applications

This paragraph delves into the origins of sonar equipment from World War II and its surplus leading to its repurpose in medical settings. The University of Colorado in the 1960s utilized this equipment for scanning, albeit impractically due to the requirement of submersion in water. The script then transitions to the development of contact B scanners, which eliminated the need for a water path and allowed direct skin contact for imaging. Life Magazine's coverage of ultrasound in pregnancy is mentioned, illustrating the shift towards more practical applications. The evolution continues with the advent of real-time moving pictures by the mid-1990s, necessitating dual monitors for grayscale and color imaging. The paragraph concludes with the miniaturization attempts of ultrasound devices, including a battery-powered bedside unit and the emergence of laptop-like machines with high-resolution screens for versatile medical use.

10:03

📡 Innovations in Portable Ultrasound Technology

The final paragraph introduces recent innovations in portable ultrasound devices, emphasizing the convenience and practicality of cordless operation. Siemens' Accuson brand is highlighted for its Bluetooth-enabled transducer, which allows for use in sterile surgical environments without the risk of contamination from cords. The script also mentions the ongoing trend of miniaturization, with many manufacturers now offering handheld units that, while not matching the capabilities of larger machines, provide satisfactory image quality for specific applications. The paragraph underscores the continuous drive for innovation in ultrasound technology, making it increasingly accessible and versatile for various medical scenarios.

Keywords

💡Ultrasound

Ultrasound refers to sound waves with frequencies higher than the audible range of human hearing. In the context of the video, it is a medical imaging technique that uses high-frequency sound waves to create images of the inside of the body. The video traces the evolution of ultrasound technology from its early beginnings in 1949 to modern high-resolution imaging, highlighting its significant role in medical diagnostics and treatment.

💡Point of Care

Point of care (POC) in the video refers to medical tests and procedures performed at or near the site of patient treatment. It emphasizes the convenience and immediacy of care. The video mentions that the first use of ultrasound was a form of POC, used in battlefield scenarios to detect foreign bodies that were not visible on X-rays.

💡Oscilloscope

An oscilloscope is a device that graphically displays varying signal voltages, in this case, used to visualize the ultrasound signals. The video describes how early ultrasound machines used oscilloscopes to display the spikes that represented the distance to structures within the body, which was a rudimentary form of imaging compared to today's sophisticated ultrasound images.

💡Resolution

In the context of the video, resolution refers to the level of detail that can be seen in an ultrasound image. The speaker discusses how modern ultrasound equipment has sub-millimeter resolution, allowing for the detection of very small structures and abnormalities, such as a ventricular septal defect in a fetal heart.

💡Transducer

A transducer in ultrasound is a device that converts electrical energy into sound waves and vice versa. The video mentions the evolution of transducers from large, non-portable devices to handheld units with high-frequency capabilities, which has significantly improved the portability and versatility of ultrasound machines.

💡Color Doppler

Color Doppler is a technique used in ultrasound to visualize the flow of blood within the body. The video explains how color Doppler was initially displayed on a separate monitor due to resolution limitations but has since been integrated into modern ultrasound machines, allowing for a more comprehensive view of blood flow and tissue movement.

💡3D Ultrasound

3D ultrasound is a technology that provides three-dimensional images of structures within the body. The video showcases the advancements in ultrasound technology that now allow for 3D imaging, where images can be rotated and viewed from different angles, providing a more detailed and comprehensive understanding of the body's structures.

💡Fetal Imaging

Fetal imaging is the use of ultrasound to visualize the fetus in the womb. The video provides examples of early pregnancy ultrasound scans, illustrating the progression from basic black and white images to detailed 3D scans that can capture the nuances of fetal development and detect abnormalities.

💡Sonar

Sonar, or Sound Navigation and Ranging, is a technique that uses sound propagation to navigate, communicate with, or detect objects on or under the surface of the water. The video discusses how surplus sonar equipment from World War II was repurposed for medical ultrasound, highlighting the military origins of the technology.

💡Miniaturization

Miniaturization in the context of the video refers to the process of reducing the size of ultrasound equipment. The speaker describes how ultrasound machines have evolved from large, stationary units to handheld devices, making them more portable and accessible for various medical applications.

💡B-Mode

B-Mode, or Brightness Mode, is a type of ultrasound imaging that displays the intensity of the returning sound waves as brightness variations on a two-dimensional plane. The video mentions B-Mode in the context of early ultrasound technology, where images were constructed by moving a transducer across the body to create a picture.

Highlights

In 1949, the first known article about the use of ultrasound in humans was published by the Department of Defense, focusing on detecting foreign bodies in battlefield injuries.

Dr. George Ludwig's initial ultrasound application was to locate non-radio opaque materials like glass or wood in post-accident scenarios.

The early ultrasound technology was not portable and required connection to an AC power line.

In 1974, ultrasound images were rudimentary, with spikes on an oscilloscope used to measure distances to structures.

Ultrasound technology has evolved significantly, from basic distance measurements to detailed 3D imaging with soft and bony tissue information.

Early ultrasound images were bistable, black and white, and required a Polaroid camera for permanent records.

Modern ultrasound scans provide detailed images of early pregnancies, including the embryo and yolk sac, with high-resolution capabilities.

Current ultrasound technology can detect minute details such as a ventricular septal defect in a fetal heart.

Resolution in modern ultrasound is sub-millimeter, allowing for the observation of fetal emotions in 3D scans.

Dr. Bill McKinney, a neurologist and enthusiastic promoter of ultrasound, contributed significantly to the field's growth.

Surplus WWII sonar equipment was repurposed for medical ultrasound research in the 1960s.

Early ultrasound scans during pregnancy involved a water path concept and were displayed on oscilloscope screens.

Contact B scanners eliminated the need for a water path, allowing direct skin contact for ultrasound imaging.

By the mid-1990s, ultrasound units featured real-time moving pictures and color Doppler capabilities.

Miniaturization of ultrasound technology led to handheld devices suitable for specific applications.

Siemens introduced a cordless ultrasound device with a high-frequency radio band for hospital use, enhancing sterility in surgical fields.

Transcripts

1949 i'm an old guy i was only four

years old at the time

the first

article that we know anything about

having to do with the use of ultrasound

in humans came out from the department

of defense from dr george ludwig who

interestingly was using it to look for

foreign bodies

after accidents in the battlefield for

example where you can have things like

glass or wood that are not radio opaque

so they don't show up on x-ray he was

hoping that this might be a way to

actually be able to detect these and it

turns out you can't so this was kind of

an early point of care you know the

point of care thing we kind of is a new

buzzword in ultrasound but so the very

first application was really sort of

point of care the difference was of

course you had to be able to plug this

oscilloscope into an ac power line so it

wasn't exactly portable

but so 1949 that was kind of the

beginning of the concept

now when i started doing ultrasound in

1974

that was an ultrasound we didn't have

images they didn't look like anything

there were these spikes on an

oscilloscope they were purely used to

measure distance to some structure this

is actually measuring from the skull

surface to the midline this is the third

ventricle in here and then that's the

far side of the skull and the hair on

the other side

so

ultrasound has come a long way in the

length of time that i've been fortunate

enough to be involved with it

this was an early ultrasound that's a

early pregnancy where the green arrows

pointing to the fetus

this display is black or white there's

no shades of gray so it's what was

called bistable either on or off and it

was on an oscilloscope if you wanted a

permanent picture you had to take a

picture of the oscilloscope with a

polaroid camera well if you compare that

with what we can do now where we have

the 3d that we can rotate around look in

any direction we have all the soft

tissue and bony information just

remarkable how far it's come in you know

a relatively short period of time so

this is representative of a current high

quality ultrasound scan this is a

transvaginal ultrasound scan of an early

pregnancy and you can see a lot of

things and we'll come back to this same

image a number of times for different

reasons in the course of the talk but so

here's the embryo here this little

bright structure is a yolk sac right out

at the periphery of the amnion the fluid

within the amniotic sac is echo-free the

fluid between the amnion and the corion

has some proteinaceous debris in it so

it has some fine internal echoes and

then when we get out into the placental

tissue and the myomet the muscle of the

uterus of different textures that

actually are helpful to us in deciding

actually what we're looking at and

whether it's normal or abnormal

now in terms of resolution of current

equipment this is a picture of a fetal

heart the four chambers two ventricular

chambers two atria here and this is a

nickel and the heart is about the size

of a nickel at 20 weeks and 20 weeks is

when we usually do the anatomic survey

well not only that but we're able to see

in this case a ventricular septal defect

on color doppler where we're showing

where flow goes flow crosses the septum

and that little defect is about the size

of jefferson's nose so our resolution

now is sub millimeter in most cases and

when we talk about frequency and that

kind of stuff we'll talk about how we

get to this level of resolution and what

you have to do to maximize that on the

equipment wow we can even see fetal

emotions on the 3d this one's obviously

frustrated

you know here's one that's like mr bill

you know who knew

the thinker you know

my favorite one a little

combative action between the twins here

and uh this one who's a little boy who's

just discovered that he's a little boy

well okay so i have to put in my

profound statement so

the one who drinks water should think of

the one who dug the well supposedly a

chinese philosopher who knows but anyway

we should remember the people that let

us get to where we are today and the one

that certainly got me here

and jim ray probably too who is our ge

person with us today was this guy dr

bill mckinney he was a neurologist the

most enthusiastic person i've ever known

he could sell ice to the eskimos and

make them grateful for it

he went on to become the president of

the american institute of ultrasound in

medicine and pulled many many people

some kicking and screaming like me into

this field and we're very grateful to

him for that

dr mckinney died not too many years ago

this was a gathering just before his

death

to honor his career at bowman gray wake

forest where he spent his entire career

you can see me in the picture but you

can also see dr kim in the picture long

before we had any idea we'd be fortunate

enough enough to have him as a colleague

at texas tech so this was 10 years ago

okay sonar

you ain't got a thing if you ain't got

that ping if you're

familiar with that well anyway

the sonar equipment that was used in

world war ii obviously like with most

things military they made a lot more of

it than it turned out we needed

the war ended and there was always

surplus equipment around this was

actually a submarine i got to visit in

san francisco that's now a museum and

you can see the sonar equipment just

racks of equipment here and this allowed

you to steer the

transducer which is this thing up on the

deck so this pipe went up came up here

and if you turn this wheel you can

actually point this thing in different

directions you had to do that manually

and then you could record

the intensity of any incoming

information and maybe figure out that

there was another sub or a ship on the

surface out there

well that same equipment ended up this

is at the university of colorado back in

the

1960s you can see the same equipment

basically in this rack over here and

they borrowed this gun turret and filled

it with water and whatever they wanted

to scan since it was sonar they figured

it had to be submersed in water so their

subjects are holding lead weights to

keep them from floating up this actually

made pretty good pictures they had this

automated transducer array that went

around oscillating as it went around it

would make pictures of the neck and you

can see all the strap muscles and the

vessels everything else is really

impressive but obviously not very

practical for day-to-day patient care

well in the evolution of things this

life magazine article also from the 60s

from honeman

shows a lady getting an ultrasound scan

in pregnancy and you can see there's

this plastic bag filled with water so we

still have what's called the water path

concept and the displays fetal head is

here on an oscilloscope screen that was

still pretty amazing because you could

tell some things you couldn't tell

before presentation if you weren't

successful with your leopold maneuvers

and figuring out the position well then

the equipment went on to become what we

call contact b scanners they found that

you could get rid of the water path and

just make contact directly with the skin

and this is me many years and a lot more

hair ago and if you look carefully up in

the edge that's jim ray who's your next

speaker so we came out of the same

training program i did not have anything

to do with getting him here today but i

am so glad because he is of all the

people in the world that know the logic

e there's just nobody better so we're

very fortunate to have jim with us today

well when i first came out here in 1977

that's jim ray again he was one of my

first two sonographers so our track

record goes way back again what we're

using here is a contact b scanner i had

an arm that came out an articulated arm

that would keep track of where in space

you were pointed it was certainly not

moving pictures you just constructed an

image by moving this thing across the

body rather like an etch a sketch

and made fairly good pictures though

that one was actually by now had

16 or maybe even 32 shades of grey so

you could differentiate for example

fluid or a bladder

from tissue like liver

really not a bad piece of equipment

by the mid 1990s we had this unit which

was from toshiba but the thing to notice

is it has two monitors on it by this

time we have real-time moving pictures

and we'll talk about how you do that

when we get to transducers in a minute

but it had to have the two monitors

because by now we were doing color

doppler the color monitors at the time

were not high enough resolution to

display the grayscale images so you

actually had to have one one monitor for

the gray information and one for color

information and this thing obviously is

the size of a of a good sized washing

machine

well

even before that people have been trying

to miniaturize things this has actually

what's called a linear array transducer

built into it and it would make moving

pictures on this little two inch

maybe three or four shades of gray

screen and it was used at the bedside to

look at heart or maybe fetal

presentation or something like that it

was battery powered but the battery only

lasted a couple of hours just never

quite caught on just wasn't quite good

enough for the job

well by the

oh within the last five or six years a

lot of the manufacturers including ge

started coming out with what basically

looked like laptop computers that have

remarkable capabilities

again by now the screen resolution is

good enough that we can do color and

grayscale on the same screen

and the controls are very logically laid

out maybe that's why it's called the

logic

whatever these logic e as in emergency i

guess

and so they started finding use like

this from the olympics back in 2008

where you know looking for

musculoskeletal injuries joint effusions

things like that you could just have it

right out there and

ready for immediate use without having

to ship the person back to some central

facility

and then they got smaller and smaller

and certainly a lot of the manufacturers

now have handheld

units and some of them actually the

quality is is not bad for if it's being

used for the right purpose they can't

compete with the bigger equipment

completely

this just announced this past november

at the radiologic society of north

america meeting

is this little unit from siemens that's

under the accuson brand name

the thing about this is the transducer

over here has no cord so this is

essentially bluetooth on steroids it

uses a very high frequency radio band so

that it doesn't interfere with other

equipment in the hospital now why would

you want to do that well it's just nice

to get rid of the cord for one thing

like in any of the bluetooth

applications but the other thing is in

say you want to use it in surgery in the

sterile field you can just slip this

little transducer sterilize it first

clean it put it in a sterile plastic bag

and then you actually have the controls

that work the equipment on the surface

so you've got everything right there no

cord to contaminate or drag across

things so

people keep coming up with clever ideas