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

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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.

Greater Trochanteric Pain Syndrome

In a study funded in part by AIUM’s Endowment for Education and Research, Jon Jacobson, MD, and his team from the University of Michigan set out to determine the effectiveness of percutaneous tendon eer_logo_textsidefor treatment of gluteal tendinosis. The full results of this study were recently published in the Journal of Ultrasound in Medicine.

Greater trochanteric pain syndrome is a condition that most commonly affects middle-aged and elderly women but can also affect younger, and more active, individuals. It has been shown that the underlying etiology for greater trochanteric pain syndrome is most commonly tendinosis or a tendon tear of the gluteus medius, gluteus minimus, or both at the greater trochanter and that tendon inflammation (or tendinitis) is not a major feature. This condition can be quite debilitating and often does not respond to conservative management.

Treatment of greater trochanteric pain syndrome should therefore include treatment of the underlying tendon condition. Ultrasound-guided percutaneous needle fenestration (or tenotomy) has been used to effectively treat underlying tendinosis and tendon tears, including tendons about the hip and pelvis. Similarly, autologous platelet-rich plasma (PRP), often combined with tendon fenestration, has been used throughout the body to treat tendinosis and tendon tears.

Although studies have shown patient improvement with PRP treatment, the true effectiveness of this treatment compared to other treatments remains uncertain. Although percutaneous ultrasound-guided tendon fenestration has been shown to be effective about the hip and pelvis, there are no data describing the use of PRP for treatment of gluteal tendons, and there is no study comparing the effectiveness of each treatment for gluteal tendinopathy. The purpose of this blinded prospective clinical trial was to compare ultrasound-guided tendon fenestration and PRP for treatment of gluteus tendinosis or partial-thickness tears in greater trochanteric pain syndrome.

We designed a study in which patients with symptoms of greater trochanteric pain syndrome and ultrasound findings of gluteal tendinosis or a partial tear (<50% depth) were blinded and treated with ultrasound-guided fenestration or autologous PRP injection of the abnormal tendon. Pain scores were recorded at baseline, week 1, and week 2 after treatment. Retrospective clinic record review assessed patient symptoms.

To break this down a little further, the study group consisted of 30 patients (24 female), of whom 50% were treated with fenestration and 50% were treated with PRP. The gluteus medius was treated in 73% and 67% in the fenestration and PRP groups, respectively. Tendinosis was present in all patients. In the fenestration group, mean pain scores were 32.4 at baseline, 16.8 at time point 1, and 15.2 at time point 2. In the PRP group, mean pain scores were 31.4 at baseline, 25.5 at time point 1, and 19.4 at time point 2. Retrospective follow-up showed significant pain score improvement from baseline to time points 1 and 2 (P < .0001) but no difference between treatment groups (P = .1623). There was 71% and 79% improvement at 92 days (mean) in the fenestration and PRP groups, respectively, with no significant difference between the treatments (P >.99).

These results led us to conclude that both ultrasound-guided tendon fenestration and PRP injection are effective for treatment of gluteal tendinosis, showing symptom improvement in both treatment groups.

What is your experience with treating greater trochanteric pain syndrome? Are you familiar with the Endowment for Education and Research?  Share your thoughts and ideas here and on Twitter: @AIUM_Ultrasound.

Jon A. Jacobson, MD, is Professor of Radiology, Director of the Division of Musculoskeletal Radiology, Assistant Medical Director of Northville Health Center, and Medical Director of Taubman Radiology within the University of Michigan Health System.

Who Runs the AIUM?

Have you ever wondered what or who runs the AIUM? Of course you know about the elected officers, and the AIUM staff that works in the home office, but do you know that there are approximately a dozen committees and/or task forces that help the organization run throughout the year?

The volunteers may be elected or appointed to the committees and tasks forces, and they are not paid or compensated for their time. Frequently, there are many committee members who accept appointments and nominations year after year. Who would possibly be willing to take on extra work and added expense, just to help the AIUM?

Bagley_6Who are the volunteers?
Ordinary people like me! That is who! I have been volunteering with the AIUM since 2009, and have found, as they often say when you volunteer, that I get more than I give. My personal life mission is one of giving back, both to my profession and to my community. I believe anyone who volunteers for the AIUM will give you a similar answer: There is an obligation to give back because someone once gave of his or her time to help me.

How did I become a volunteer?
I did not wake up one day and think to myself, “Today is the day I should volunteer for the AIUM.” Instead, a mentor suggested to a liaison organization that I should be their representative to the AIUM Bioeffects and Safety Committee. At the first meeting, I was hooked. The work gave me new energy and excitement about my profession. I could not get enough bioeffect and safety knowledge.

When my time as a liaison ended, I asked a fellow committee member to nominate me to the committee. As luck would have it, my work proved that I was serious, and the members elected me to the committee.

How can you become a volunteer?
Maybe you are thinking to yourself right now, I am energetic and have a lot to give, but I do not know how to get involved. What should I do? If you have a mentor in the AIUM, ask him or her to nominate you to a committee.

If you do not have a mentor I suggest that you start by serving as a resource member to the committee that best matches your skills and interests. A resource member might assist the members on projects. You can offer up your talents by contacting the chair and letting him or her know that you want to help. Once your work is visible, you can ask a member to nominate you to be a committee member.

You Get More Than You Give
I have gained so much from working on a committee. I have new knowledge about bioeffects and safety that has allowed me to take on a larger advocacy role. I have new knowledge to integrate into the courses that I teach, and I have developed lectures to educate all medical imaging professionals about ultrasound bioeffects and safety. The work on the committee has inspired my own research projects that have resulted in award-winning manuscripts.

My confidence in my knowledge has improved, and I am willing to try new and difficult projects that I would not have dreamed of trying in my pre-committee life. I have made friends and have gained new mentors. I know that regardless of how much effort I have given, the committee has given me exponentially more.

Member, Pay it Forward!
None of us ever gets where we are on our own. In addition to our hard work, our mentors and our colleagues help us on our professional journeys. Volunteering is a way to pay it forward.

If you are an active volunteer, now is the time to make sure your good work is continued! Mentor a new member, and help him or her get involved. Suggest that he or she become a resource member or nominate him or her to a committee. Bringing new people into the volunteer world ensures that your good work continues, and it provides for the AIUM’s future.

Interested in volunteering for the AIUM? Check out the volunteer page. What has been your volunteer experience? Comment below or let us know on Twitter: @AIUM_Ultrasound.

Jennifer Bagley, MPH, RDMS, RVT, is an associate professor for the College of Allied Health at the University of Oklahoma Health Sciences Center, Schusterman Campus in Tulsa. She currently serves on the AIUM Bioeffects Committee and is a former member of the Technical Standards Committee.