Pioneering Ultrasound Units

If you think your ultrasound machine is out-dated, imagine if you still had to use these from as long ago as the 1940s. 

1940s

Ultrasonic Locator
Dr G. D. Ludwig, a pioneer in medical ultrasound, concentrated on the use of ultrasound to detect gallstones and other foreign bodies embedded in tissues. During his service at the Naval Medical Medical Research Institute in Bethesda, Maryland, Dr Ludwig developed this approach that is similar to the detection of flaws in metal. This is A-mode in its operation and was Dr Ludwig’s first ultrasonic scanning equipment.

Locator

 

1950s

Ultrasonic Cardioscope
Designed and built by the University of Colorado Experimental Unit, the Cardioscope was intended for cardiac work.

Ultrasonic Cardioscope

 

1960s

Sperry Reflectoscope Pulser / Receive Unit 10N
This is an example of the first instrument to use an electronic interval counter to make axial length measurements of the eye. Individual gates for the anterior segment, lens, and vitreous compartment provided accurate measurement at 10 and 15 MHz of the axial length of the eye. This concept was the forerunner of all optical axis measurements of the eye, which are required for calculation of the appropriate intraocular lens implant power after cataract extraction. This instrument, which includes A-mode and M-mode, was developed by Dr D. Jackson Coleman and Dr Benson Carlin at the Department of Ophthalmology, Columbia Presbyterian Medical Center.

Sperry Reflectoscope Pulser

 

Sonoray Model No. 12 Ultrasonic Animal Tester (Branson Instruments, Inc.)
This is an intensity-modulated B-mode unit designed exclusively for animal evaluations. The instrument is housed in a rugged aluminum case with a detachable cover that contains the cables and transducer during transportation. The movable transducer holder on a fixed-curve guide was a forerunner of mechanical B-scan ultrasonic equipment.

Sonoray Animal Tester

 

Smith-Kline Fetal Doptone
In 1966, pharmaceutical manufacturer Smith Kline and French Laboratories of Philadelphia built and marketed a Doppler instrument called the Doptone, which was used to detect and monitor fetal blood flow and the heart rate. This instrument used the continuous wave Doppler prototype that was developed at the University of Washington. 

Smith Kline Fetal Doptone

 

Smith-Kline Ekoline 20
Working in collaboration with Branson Instruments of Stamford, Connecticut, Smith-Kline introduced the Ekoline 20, an A-mode and B-mode instrument for echoencephalography, in 1963. When B-mode was converted to M-mode in 1965, the Ekoline 20 became the dominant instrument for echocardiography as well as was the first instrument available for many start-up clinical diagnostic ultrasound laboratories. The A-mode was used in ophthalmology and neurology to determine brain midlines.

Ekoline 20

 

University of Colorado Experimental System
Developed by Douglas Howry and his team at the University of Colorado Medical Center, this compound immersion scanner included a large water-filled tank. The transducer moved back and forth along a 4-inch path while the carriage on which the transducer was mounted moved in a circle around the tank, producing secondary motion necessary for compound scanning. 

Compound immersion scannerCompound immersion scanner tub

 

1970s

Cromemco Z-2 Computer System (Bioengineering at the University of Washington)
This color-Doppler prototype, introduced in 1977, was the computer used for early color Doppler experiments. Z2 “microcomputers” were used for a variety of data acquisition and analysis applications, including planning combat missions for the United States Air Force and modeling braking profiles for the San Francisco Bay Area Rapid Transit (BART) system during actual operation.

Cromemco Z-2 Computer System

 

ADR-Model 2130
ADR of Tempe, Arizona, began delivering ultrasound components to major equipment manufacturers in 1973. Linear array real-time scanners, which began to be manufactured in the mid-1970s, provided greater resolution and more applications. Grayscale, with at least 10 shades of gray, allowed closely related soft tissues to be better differentiated. This 2-dimensional (2D) imaging machine was widely used in obstetrics and other internal medicine applications. It was marketed as an electronic linear array, which was faster and more repeatable without the need for a water bath as the transducer was placed right on the skin.

ADR Model 2130

 

Sonometrics Systems Inc, NY BR-400V
The first commercially available ophthalmic B-scanner, this system provided both linear and sector B-scans of the eye. The patient was examined in a water bath created around the eye by use of a sterile plastic ophthalmic drape with a central opening. Both A-scan and B-scan evaluations were possible with manual alignment of the transducer in the water bath. The instrument was developed at the Department of Ophthalmology, Columbia Presbyterian Medical Center by Dr D. Jackson Coleman, working with Frederic L. Lizzi and Louis Katz at the Riverside Research Institute.

Sonometrics Systems Inc, NY BR-400V

 

Unirad GZD Model 849
Unirad’s static B-scanner, allowing black-and-white anatomic imaging, was used with a scan arm and had similar controls as those used today, including processing, attenuation compensation, and gain.

Unirad GZD Model 849

 

1980s

American Flight Echocardiograph
This American Flight Echocardiograph (AFE) is a 43-pound off-the-shelf version of an ATL 400 medical ultrasonic imaging system, which was then modified for space shuttle compatibility by engineers at the Johnson Space Center to study the adaptations of the cardiovascular system in weightlessness. Its first journey to space was on the space shuttle Discovery in 1985 and its last on the Endeavour in 1992. The AFE generated a 2D cross-sectional image of the heart and other soft tissues and displayed it in video format at 30 frames per second. Below, Dr Fred Kremkau explains more about it.

 

To check out even more old ultrasound machines, visit the American Institute of Ultrasound in Medicine’s (AIUM’s) An Exhibit of Historical Ultrasound Equipment.

 

How old is the ultrasound machine you use now? What older ultrasound equipment have you used? Did it spark your desire to work with ultrasound? Comment below, or, AIUM members, continue the conversation on Connect, the AIUM’s online community.

Connect_digital_graphics_E-NEWSLETTER

The AIUM is a multi-disciplinary network of nearly 10,000 professionals who are committed to advancing the safe and effective use of ultrasound in medicine.

Physics of Ultrasound

Snell’s Law [in-class demonstration]

The concept that sound reflects and propagates in varied angles is an abstract concept that many students struggle to understand. I review this concept by providing an in-class demonstration that makes this less abstract and something that can be seen with glasses of liquids.

Evans_Fig 1

 

If speed 1 < speed 2, then the incident angle < transmitted angle.

The difference in the stiffness and resulting propagation speeds helps to explain why the straw appears to be “broken” when you look through the side of the glass of water. The angle of transmission is measured against the vertical black line drawn on the glass of water. This helps to illustrate the 30-degree oblique incidence vs. the increased angle of transmission. A real-world example would be the change in imaging of a needle in a fluid-filled structure.

Example:

The propagation speed of sound through air is 900 m/sec while the propagation speed of sound through water is 1200 m/sec. To figure out the change in the angle of transmission, we form a ratio that will allow us to arrive at a percentage of change. So, 900/1200 = .75 and, therefore, that ratio of change from air to water in the glass is 100 – 75 = 25%. To figure out the angle, take 30 times .25 = 7.5 degrees. Therefore, 30 + 7.5 = 37.5 degree angle of transmission.

Now, consider a different glass of liquid as part of this demonstration by viewing a glass of Karo syrup.

Evans_Fig 2

This time, the glass is filled with Karo syrup, which is stiffer and denser than the water, and the transmitted angle is greater due to the increased ability to travel quickly in the second media.

 

If speed 1 < speed 2, then the incident angle < transmitted angle.

Example:

The propagation speed of sound through air is 900 m/sec while the propagation speed of sound through Karo is 1500 m/sec. To figure out the change in the angle of transmission, we form a ratio that will allow us to arrive at a percentage of change. So, 900/1500 = .60 and, therefore, the ratio of change from air to Karo syrup in the glass is 100 – 60 = 40% gain. To figure out the angle, take 30 times .4 = 12 degrees. 30 + 12 = 42 degree angle of transmission. The real world example for this is noting a speed propagation artifact.

A final demonstration can be a glass that has 1/3 air, 1/3 vinegar, and 1/3 cooking oil. Do not forget to add a straw so that several bends in the straw are noted by viewing through the side of the glass.

 

 

Kevin D. Evans, PhD, RT (R) (M) (BD), RDMS, RVS, FSDMS, FAIUM, is Chair and Professor of Radiologic Sciences and Respiratory Therapy at The Ohio State University in Columbus, OH.

 

Can Ultrasound be Used to Improve Prosthetic Device Function?

Ultrasound technology has continued to be miniaturized at a rapid pace for the past several decades. Recently, handheld smartphone-sized ultrasound systems have emerged and are enabling point-of-care imaging in austere environments and resource-poor settings. With further miniaturization, one can imagine that wearable smartwatch-sized imaging systems may soon be possible. What new opportunities can you imagine with wearable imaging? My research group has been pondering this question for a while, and we have been working on an unexpected application: using ultrasound imaging to sense muscle activity and volitionally control robotic devices.Bebionic

Since antiquity, humans have been working on developing articulated prosthetic devices to replace limbs lost to injury. One of the earliest designs of an articulated mechanical prosthetic hand dates from the Second Punic War (218–201 BC). However, robust and intuitive volitional control of prosthetic hands has been a long-standing challenge that has yet to be adequately solved. Even though significant research investments have led to the development of sophisticated mechatronic hands with multiple degrees of freedom, a large proportion of amputees eventually abandon these devices, often citing limited functionality as a major factor.

A major barrier to improving functionality has been the challenge of inferring the intent of the amputee user and to derive appropriate control signals. Inferring the user’s intent has primarily been limited to noninvasively sensing electrical activity of muscles in the residual limbs or more invasive sensing of electrical activity in the brain. Commercial myoelectric prosthetic hands utilize 2 skin-surface electrodes to record electrical activity from the flexor and extensor muscles of the residual stump. To select between multiple grips with just these 2 degrees of freedom, users often have to perform a sequence of non-intuitive maneuvers to select among pre-programmed grips from a menu. This rather unnatural control mechanism significantly limits the potential functionality of these devices for activities of daily living.

Recently, systems with multiple electrodes that utilize pattern recognition algorithms to classify the intended grasp end-state from recorded signals have shown promise. However, the ability of amputees to translate end-state classification to intuitive real-time control with multiple degrees of freedom continues to be limited.

To address these limitations, invasive strategies, such as implanted myoelectric sensors are being pursued. Another approach, known as targeted muscle reinnervation, involves surgically transferring the residual peripheral nerves from the amputated limb to different intact muscle targets that can function as a biological amplifier of the motor nerve signal.  While these invasive strategies have exciting promise, there continues to be a need for better noninvasive sensing.

Recently, our research group has demonstrated that ultrasound imaging can be used to resolve the activity of the various muscle compartments in the residual forearm. When amputees imagine volitionally controlling their phantom limb, the innervated residual muscles in the stump contract and this mechanical contraction can be visualized clearly on ultrasound. Indeed, one of the major strengths of ultrasound is the exquisite ability to quantify even minute tissue motion. Contractions of both superficial and deep-seated functional muscle compartments can be spatially resolved enabling high specificity in differentiating between different intended movements.

Our research has shown that sonomyography can exceed the grasp classification accuracy of state-of-the-art pattern recognition, and crucially enables intuitive proportional position control by utilizing mechanical deformation of muscles as the control signal. In studies with transradial amputees, we have demonstrated the ability to generate robust control signals and intuitive position-based proportional control across multiple degrees of freedom with very little training, typically just a few minutes.

We are now working on miniaturizing this technology to a low-power wearable system with compact electronics that can be incorporated into a prosthetic socket and developing prototype systems that can be tested in clinical trials. The feedback we have received so far from our amputee subjects and clinicians indicates that this ultrasound technology can overcome many of the current challenges in the field, and potentially improve functionality and quality of life of amputee users.

Now, if only noninvasive ultrasound neuromodulation can be used to provide haptic and sensory feedback to amputee users in a closed loop ultrasound-based sensing and stimulation system, we will be a step closer to restoring sensorimotor functionality to amputee users, and a grand challenge in the field of neuroprosthetics may be within reach. That will, of course, require some more research.

I was attracted to ultrasound research as a graduate student because of the nearly limitless possibilities of ultrasound technology beyond traditional imaging applications. As wearable sensors revolutionize healthcare, perhaps wearable ultrasound may have a role to play. One can only imagine what other novel applications may be enabled as the technology continues to be miniaturized. I think it is an exciting time to be an ultrasound researcher.

What new opportunities can you imagine with wearable imaging? Are you working on something using miniaturized ultrasound? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Siddhartha Sikdar, PhD, is a Professor in the Bioengineering Department in the Volgenau School of Engineering at George Mason University.

How to Commercialize Ultrasound Technology

A few years ago, I had the opportunity to commercialize an ultrasound technology. Reflecting upon this process, I am very grateful that there were so many team members and things (including those beyond our control) that contributed to the success of the project. By sharing our journey from the research bench to public use, I hope that people will get an idea of what is involved in a commercialization process and appreciate the importance of team work.Chen_Shigao_2016

It started with our research team who sketched out an idea of using multiple push beams spaced out like a comb to generate multiple shear waves at the same time. It could be used to improve both signal-to-noise ratio and the frame rate for ultrasound elastography. Fortunately our lab had a research scanner that came with a programmable platform. This idea was prototyped and tested on the same day and it worked! Were it not for the research scanner, it would have taken months to get this done. The alternative process involves contacting an ultrasound company (if we ever find one), gaining their support (a research agreement could take months to reach), and testing on a commercial prototype scanner (which is much harder compared to using a research scanner).

It was soon discovered afterwards that the interference of shear waves from the comb push beams make it very hard to calculate the wave speed for elasticity imaging accurately. A mathematician in our team offered to apply a signal processing algorithm that detangles the complicated shear waves into simpler component waves. It solved our problem and helped the idea pass the initial functionality test. The next step was to show the industry the translational potential of this technology and out-license it to them for further development and testing.

Back then, the clinical ultrasound division at our institution was developing a strategic partnership with a leading ultrasound company, which was looking for a shear wave elastography solution for their products. The company soon decided to license our technology. To speed up the progress, our intellectual property (IP) office negotiated the licensing agreement with the company, while we worked with the company engineers on the technology in parallel. Both parties shared a common culture of openness, which allowed us to exchange codes with each other. This trusting relationship was found to be very beneficial by both sides as we shared the dedication to achieve common goals quickly.

To ensure the successful implementation of the prototype, the collaboration continues in the form of site visits and numerous teleconferences between the sites until satisfied phantom and in vivo results were yielded. When the near-end prototype was available, an independent clinical study was performed at our institution to verify the performance and establish cut points for liver fibrosis staging. It greatly exemplified the benefit of affiliating with a large medical center. The extensive interdisciplinary research and medical environment at our institution has provided a unifying framework that bridges the gap of technical creation and clinical deployment. Upon positive results from clinical trials, the company was able to launch the product in 2014. The technique was FDA-approved and released at RSNA. We are very pleased to see the research outcome has been taken from the bench to the bedside and is improving the effectiveness of patient care worldwide.

It truly takes a village to make this happen. The success came with the supports of a huge team of ultrasound physicist, PhD student, mathematician, study coordinator, sonographer, radiologist, IP staff, and licensing manager. It calls for an industrial partner that has shared appreciation of value and common core objectives. Looking back at our journey, it is without question that every step presents its own challenge. By sharing our experiences, we hope to contribute to your future successful technology commercialization.

Have you tried to commercialize an ultrasound technology? Have you had a different experience commercializing ultrasound technology? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Shiago Chen, PhD, is a Professor at the Department of Radiology, Mayo Clinic College of Medicine.

Portable Ultrasound for the Win

todiian_pic

Tommaso Di Ianni, MSc
2017 New Investigator Award winner for Basic Science

What does being named the New Investigator Award winner mean to you?

It was an honor being appointed the New Investigator Award for the Basic Science category for “In Vivo Vector Flow Imaging for a Portable Ultrasound Scanner.” It means a lot to me to see my scientific contributions being recognized by some of the leading experts in the field. It provides a great stimulus to continue to focus on researching imaging solutions that will hopefully improve the clinical practice.

How did you get into working with ultrasound?

After the masters, I was looking for open PhD positions, and I found an opening about portable ultrasound imaging at Professor Jørgen A. Jensen’s Center for Fast Ultrasound Imaging at the Technical University of Denmark. I didn’t know much about ultrasound at the time, but I was fascinated about its great capabilities as a risk-free imaging modality. Even more, I was attracted by the fact that ultrasound scanners can be scaled like any other electronic device and can become so small it can fit in a lab coat pocket. Currently, this does not apply to other imaging technologies, and I believe that ultrasound has a lot of potential to make a difference at the point of care.

What do you like the most about working with ultrasound?

I am overwhelmed about the patterns that the blood can depict when flowing into the vessels. With ultrasound, we can obtain a very high temporal resolution and we can visualize dynamic details on a millisecond scale. Sometimes, we can see vortices forming when the valves in the jugular vein close, or the helical flow in the ascending aorta. Also, the vortices forming in the heart are absolutely impressive to look at. I believe there’s a lot of diagnostic potential in that wealth of information.

What are your future research plans?

Currently, I’m completing my PhD and I will continue my research as a postdoc for some more months. In the future, I plan to continue to do research in the biomedical engineering field. I’m very interested in imaging the microvasculature in cancer to improve the characterization of the tumor’s functional activity and to track the response to the therapy.

Why did you become interested in ultrasound? Where did you learn your ultrasound skills? Comment below or let us know on Twitter: @AIUM_Ultrasound. Learn more about the AIUM Awards Program at www.aium.org/aboutUs/awards.aspx.

Tommaso Di Ianni, MSc, is a PhD student at Technical University of Denmark.

Puzzle Solver

During the 2016 AIUM Annual Convention, Michael Kolios, PhD, was awarded the Joseph H. Holmes Basic Science Pioneer Award. We asked him a few questions about the award,November 11, 2015 what interests him, and the future of medical ultrasound research. This is what he had to say.

  1. What does being named the Joseph H. Holmes Basic Science Pioneer Award winner mean to you?
    It means a lot to me to be recognized by my peers in this manner. It motivates me to work even harder to contribute more to the community.  I have been associated with the AIUM for a long time and have thoroughly enjoyed interacting with all the members over the years. When I peruse the list of the previous Joseph H. Holmes Basic Science Pioneer Awardees and look at their accomplishments, I feel quite humbled by being the recipient of this award, and hope one day to match their contributions to the field.
  1. What gets you excited the most when it comes to research?
    I get excited when I generate/discuss new ideas, participate in the battle of new and old ideas, and the immensely complex detective work that is required to prove or disprove these new ideas. I thoroughly enjoy the interactions with all my colleagues and trainees that join me in this indefatigable and never-ending detective work, as solving one puzzle almost always creates many new ones. This is what I’ve encountered in the last 2 decades while probing basic questions on the propagation of ultrasound waves in tissue, and how different tissue structures scatter the sound. Finally, I get very excited when I try to think about how to use the basic science knowledge generated from this research to inform clinical practice, and envisioning the day this will potentially make a difference in the lives of people.
  1. How can we encourage more ultrasound research?
    We need to provide the resources to people in order to do the research in ultrasound. Most funding agencies are stretched to the limit and success rates are sometimes in the single digits. This makes it very challenging to do research in general, including ultrasound research. Therefore, pooling resources and providing environments where ultrasonic research can excel will partially help—creating/promoting/maintaining centers for ultrasound research. This can also be promoted through networking and professional societies, such as the AIUM.Another thing to do to encourage more ultrasound research is by demonstrating the clinical impact of ultrasound and how it could be used to save the lives of patients. Only through the close collaboration of basic scientists/engineers with clinicians/clinician-scientists/sonographers can this be achieved. Developments in therapeutic ultrasound for example are very exciting, and have recently attracted the attention of both public and private funding agencies with many success stories. Moreover, providing seed money through opportunities such as the ERR (Endowment for Education and Research) is a step in the right direction—to give people the opportunity to pursue their ideas in the field of ultrasound research.
  1. What new or upcoming research has you most intrigued?
    While I spent a lot of time trying to understand ultrasound scattering, and how changes in tissue morphology influence this scattering, I’m currently dedicating most of my time to the new field called photoacoustic imaging. It is known that conventional clinical ultrasound has relatively poor soft tissue contrast, but in photoacoustic imaging light is used to generate ultrasound. These ultrasound waves, created when light is absorbed by tissue, provides exciting results that allow not only probing tissue anatomy, but also function in ways that not many other modalities can. After the light is absorbed and the waves initiated, everything we know about ultrasound applies—and in fact we can use the same ultrasound instrumentation to create images. I expect this imaging modality to have clinical impact in the near future.
  1. You are well accomplished within the medical ultrasound research community, but when you were young what did you want to be when you grew up?
    When I was young I wanted to be firstly an astronaut, then a philosopher, pondering basic questions and fundamental problems in nature. I ended up studying physics and its applications in medicine. It has been a highly rewarding choice!
  1. If you were presenting this award at the 2017 AIUM Annual Convention, who would you like to see receive it and why?
    I’d like to see someone that has contributed to ultrasound, with work spanning from the basic science/engineering to clinical application! It would also be encouraging to see the next recipient being a woman or minority, reflecting the true diversity from which new ideas come, and representing a constituency for which society has relatively recently given the opportunity to contribute to science in a meaningful and sustained manner.

Who would you like to see win an AIUM award? What ideas do you have to increase the interest in and funding for research? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Michael Kolios, PhD, is Professor in the Department of Physics, and Associate Dean of Science, Research and Graduate Studies at Ryerson University.

Research in Ultrasound: Why We Do It

“Medicine, the only profession that labors incessantly to destroy the reason for its existence.” –James Bryce

We all know the important medical discoveries clinical research has given us over time. stamatia-v-destounis-md-facrYou could even make the case that the high standards of care we have today are built on centuries of research.

The world of medical ultrasound is no stranger to clinical research—dating back to the early work of transmission ultrasound of the brain. This work was especially important, as it was the first ultrasonic echo imaging of the human body.

Since then, research has brought about gray scale imaging, better transducer design, better understanding of beam characteristics, tissue harmonics and spatial compounding, and the development of Doppler. All of these research developments, as well as many others, were highly significant and have lead us to today’s high-quality handheld, real-time ultrasound imaging.

For me, the biggest and most important developments were and have been in breast ultrasound. In 1951, the research of Wild and Neal discovered and qualified the acoustic characteristics of benign and malignant breast tumors through use of an elementary high-frequency (15-MHz) system that produced an A-mode sonogram. These researchers published the results of additional ultrasound examinations in 21 breast tumors: 9 benign and 12 malignant, with two of the cases becoming the first 2-dimensional echograms (B-mode sonograms) of breast tissue ever published.

It is research that leads to landmark publications that change the way we practice. The ACRIN 6666 trial led by Dr Wendie Berg and her co-authors evaluated women at elevated risk of breast cancer with screening mammography compared with combined screening mammography and ultrasound. This pivotal study demonstrated that adding a single screening ultrasound to mammography can increase cancer detection in high-risk women. In our current environment this is even more relevant, as breast density notification legislation is being adopted in states across the country. With the legislation, patients with dense breast tissue are often being referred for additional screening services, with ultrasound most often being the screening modality of choice.

Screening ultrasound is an area on which I have focused much of my own research. I practice in New York State, where our breast density notification legislation became effective in January 2013. I have been interested in reviewing my practice’s experience with screening ultrasound in these patients to evaluate cancer detection and biopsy rates. My initial experience was published in the Journal of Ultrasound in Medicine in 2015, and supported what other breast screening ultrasound studies have found, an additional cancer detection rate of around 2 per 1000. Through my continued evaluation of our screening breast ultrasound program, I have found a persistently higher cancer detection rate by adding breast ultrasound to the screening mammogram–which is of great importance to all breast imagers, as we are finding cancers that were occult on mammography.

Participating in valuable research is important to me and my colleagues because part of our breast center’s mission is to investigate new technologies and stay on the cutting-edge by offering the latest and greatest to our patients. Participating in clinical research provides us important experience with new technology, and an opportunity to evaluate firsthand new techniques, new equipment, and new ideas and determine what will most benefit our patients. This is what I find the most important aspect of research, and why I do it; to be able to find new technologies that improve upon the old, to continue to find breast cancers as early as possible, and to improve patient outcomes.

Why is medical research/ultrasound research so important to you? What research questions would you like to see answered? Share your thoughts and ideas here and on Twitter: @AIUM_Ultrasound.

Stamatia Destounis, MD, FACR, is an attending radiologist and managing partner at Elizabeth Wende Breast Clinic. She is also Clinical Professor of Imaging Sciences at the University of Rochester School of Medicine & Dentistry.