Low-cost, wearable sensors could increase access to care for patients with Parkinson’s disease. New machine-learning approaches and a baseline of data from healthy older adults improve the accuracy of the results from such sensors, University of Illinois Urbana-Champaign researchers and clinical collaborators found in a new study.&nbsp;“This study demonstrates that the expansion of datasets with healthy older adult motion data and integration with deep learning approaches can help improve the accuracy of detecting differences in motor impairment in persons with Parkinson's disease for use in future telemedicine sessions,” said study leader <a href="https://experts.illinois.edu/en/persons/manuel-enrique-hernandez" target="_blank">Manuel Enrique Hernandez</a>, a professor of <a href="https://medicine.illinois.edu/academics/departments/biomedical-and-translational-sciences" target="_blank">biomedical and translational sciences</a> within the <a href="https://medicine.illinois.edu/" target="_blank">Carle Illinois College of Medicine</a> at the U. of I.To have their symptoms monitored, patients with Parkinson’s disease must periodically undergo assessment — typically a time-consuming, in-person visit to a specialist with limited availability, Hernandez said.&nbsp;Evaluation by telemedicine would improve access to care for patients but is made challenging by the lack of quantifiable measurements. For example, the physician can watch the patient move, but cannot assess rigidity or muscle tone. While some progress has been made in using wearable sensors to assess motor skills, the cost limits their use.&nbsp;To address these challenges, the Illinois team focused on ways to improve assessment using low-cost wearable sensors.&nbsp;“Ideally, we’d have something that’s completely passive, gathering data as a person goes through their everyday environment and using that information to provide guidance on their overall motor function and progression of neurological symptoms. But then you face the big challenge of how to parse all that information and make it useful to a clinician,” Hernandez said. “That’s what led to our strategy of improving the machine learning, honing in on activities useful for assessment and looking at healthy individuals as a baseline.”&nbsp;The researchers adapted the gold standard of clinical assessment, the Movement Disorders Society-sponsored revision of the Unified Parkinson’s Disease Rating Scale. The MDS-UPDRS outlines specific tasks that a patient would perform and qualitative observations a physician would make during an exam and organizes them into categories for scoring.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1713912642131-225490.jpg" style="width: 100%px;" class="fr-fic fr-dib">Subjects completed tasks normally done during in-person clinical assessment with sensors on their arms, hands and feet to gather data. Image courtesy of Manuel Enrique HernandezFor their study, the researchers had patients perform tasks and muscle movements while wearing sensors to provide the data in the categories scored by MDS-UPDRS. They used data from both patients with Parkinson’s disease and from healthy older adults to train their machine learning model.&nbsp;“Improving machine learning models requires a lot of data. We hypothesized that healthy individuals can serve as the basis for what to expect with potential age-related changes. Then we could build a comparative model to get a sense of when there might be a marked change in terms of motor function or motor impairment,” said Hernandez, who also is affiliated with the departments of <a href="https://ahs.illinois.edu/kch-home" target="_blank">kinesiology and community health</a> and <a href="https://bioengineering.illinois.edu/" target="_blank">bioengineering</a>, as well as the <a href="https://beckman.illinois.edu/" target="_blank">Beckman Institute for Advanced Science and Technology</a> at Illinois.&nbsp;The researchers also used deep learning techniques known as pretraining to make the model more robust, better able to identify important data points and filter out irrelevant ones. The pretraining and the addition of healthy older adult data improved the accuracy of identifying motor impairments in hand movement tasks by more than 12% over the current standard model. Additionally, including data from healthy older adults improved the accuracy of assessing every task for the upper and lower body, except for toe tapping.&nbsp;The <a href="https://www.mdpi.com/1424-8220/23/21/9004" target="_blank">results</a> were reported in the journal Sensors.Next, the researchers hope to collaborate further with neurologists and clinicians to expand their model. They aim to identify a small number of additional tasks that could quantitatively measure more information about the classical symptoms of Parkinson’s disease, such as tremor, while maintaining low cost and ease of use for the sensors.&nbsp;“There’s a very large need for us to better understand and better quantify changes that are ongoing with Parkinson’s disease,” Hernandez said. “The ability to use wearable sensors while performing activities that are part of the course of clinical evaluations in a telehealth setting might open up the doors for more objective, more quantifiable information that can help direct treatment for individuals with Parkinson’s disease and hopefully improve quality of life moving forward.”<a href="https://ise.illinois.edu/directory/profile/r-sowers" target="_blank">Richard Sowers</a>, Illinois professor of <a href="https://ise.illinois.edu/" target="_blank">industrial and enterprise systems engineering</a> and <a href="https://math.illinois.edu/" target="_blank">mathematics</a>, and James R. Brasic, professor and neurologist at Johns Hopkins School of Medicine, New York University and NYC Health + Hospitals, were coauthors of the paper. &nbsp;&nbsp;<hr>Editor’s note: &nbsp;&nbsp;To reach Manuel Enrique Hernandez, email <a href="mailto:mhernand@illinois.edu" target="_blank">mhernand@illinois.edu</a>.&nbsp;The paper, “A deep learning approach for automatic and objective grading of the motor impairment severity in Parkinson’s disease for use in tele-assessments,” is available <a href="https://www.mdpi.com/1424-8220/23/21/9004" target="_blank">online</a>. DOI: 10.3390/s23219004This research had no external funding.&nbsp;

Illinois professors Richard Sowers, left, and Manuel Hernandez used machine learning techniques to improve data analysis from wearable sensors to detect symptoms and monitor the progression of Parkinson’s disease. Photo by Fred Zwicky

Low-cost, wearable sensors could increase access to care for patients with Parkinson’s disease. New machine-learning approaches and a baseline of data from healthy older adults improve the accuracy of the results from such sensors

Wearable sensors for Parkinson's can improve with machine learning, data from healthy adults

Haver &amp; Boecker's innovative wire mesh filters set new standards in medical technology, where smooth processes mean the difference between life and death. The same is true for the chemical industry. Here, filtration components must function perfectly even under extreme conditions and in contact with corrosive media. At ACHEMA 2024 from 10 to 14 June, the manufacturer will demonstrate why metal mesh is an economical and future-oriented solution for a wide range of applications in the process industry. In the run-up to the exhibition, free whitepapers are available to shed more light on these topics.The white paper "When tiny meshes master mighty tasks" focuses on medical applications. Three practical examples illustrate the uses and benefits of wire mesh in this sector.<h3>Focus on the patient's quality of life</h3>The demands placed on medical technology products are high, as human lives depend on their performance and quality. This is even more true for filter components, which are used to remove unwanted particles from liquids and gases. Or to separate specific materials. &nbsp;&nbsp;Wire mesh filters from Haver &amp; Boecker are used in the manufacture of artificial kidneys (dialysis machines) or in stents to prevent blood clots from entering blood vessels. &nbsp;<img width="349" src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1713767565611-1713767565611.jpeg" class="fr-fic fr-dii">A deep understanding of the industry and continuous development make Haver &amp; Boecker a reliable partner in the development of new medical devices.Blood filtration in dialysis machines uses materials with mesh sizes between 10 and 100 nanometers to remove toxins while preserving essential blood cells and proteins. The flow characteristics are designed to cleanse the blood efficiently without affecting the patient's blood pressure. &nbsp;Air filtration in ventilators uses HEPA or ULPA filters that trap micron-sized particles (around 0.3 µm for HEPA) to remove bacteria, viruses and other contaminants. Despite their high filtration efficiency, these filters still provide sufficient airflow for the patient to breathe. The ability to precisely determine the pore size and flow characteristics of Haver &amp; Boecker's wire mesh filters enables them to be precisely tailored to medical requirements.<img width="354" src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1713767565618-1713767565618.jpeg" class="fr-fic fr-dii">In the future, metal mesh could be used for targeted drug delivery to hard-to-reach areas of the body.For grease-free cleaning, heating to 1000 °C is no problem. Advanced manufacturing processes and regular quality controls ensure maximum efficiency and reliability of the wire mesh. &nbsp;<h3>Corrosion-resistant and sustainable</h3>The second white paper, "Efficient filtration in the chemical and pharmaceutical&nbsp;industry", also covers applications where chemical corrosion resistance and precise pore size are required for specific separation processes. The wire meshes used in these applications require high mechanical strength for long-term use under variable pressure conditions and thermal stability at different temperatures. Cleanability is also essential for reusability and durability. &nbsp;&nbsp;The white paper highlights the importance of efficient filtration processes in the chemical and pharmaceutical industries to maintain high product quality. Various filter media are considered, with metal mesh laminates standing out for their robustness, durability and versatility. Their resistance to high temperatures and corrosion makes them ideal for process gas filtration and other demanding applications. &nbsp;<img width="354" src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1713767565624-1713767565624.jpeg" class="fr-fic fr-dii">Filter elements, such as this filter plate for chemical applications, are developed by Haver &amp; Boecker and produced specifically for the application (also in large quantities).The ability to be cleaned and reused, combined with a long service life, makes a significant contribution to waste reduction and environmental protection. Compared to conventional materials such as ceramics or textiles, wire mesh filters offer significant advantages in terms of process stability and cost efficiency due to lower differential pressure and the ability to filter high throughput volumes without increasing system size. The result is superior filtration efficiency that minimizes production downtime and lowers the total cost of ownership while reducing environmental impact.&nbsp;At ACHEMA 2024 you can see the product quality for yourself in Hall 3.0, Stand F38. Take the opportunity to learn first-hand about the many applications and benefits of this technology. Our representatives will be happy to assist you in person. &nbsp;<a href="https://www.haverboecker.com/en/industries/medicine-and-pharmaceuticals/?lso=wevolver-brand-beitrag&utm_campaign=brand&utm_source=wevolver&utm_medium=beitrag&utm_content=_042024" target="_blank" rel="noopener noreferrer">More info &amp; download</a>

Innovative wire mesh filters set new standards in medical technology, where smooth processes mean the difference between life and death. The same is true for the chemical industry. Here, filtration components must function perfectly even under extreme conditions and in contact with corrosive media. 

Wire mesh filters: precision and reliability for the process industry

Optical sensors serve as the backbone of numerous scientific and technological endeavors, from detecting gravitational waves to imaging biological tissues for medical diagnostics. These sensors use light to detect changes in properties of the environment they’re monitoring, including chemical biomarkers and physical properties like temperature. A persistent challenge in optical sensing has been enhancing sensitivity to detect faint signals amid noise.New research from Lan Yang, the Edwin H. &amp; Florence G. Skinner Professor in the Preston M. Green Department of Electrical &amp; Systems Engineering in the McKelvey School of Engineering at Washington University in St. Louis, unlocks the power of exceptional points (EPs) for advanced optical sensing. In a study published April 5 in&nbsp;Science Advances, Yang and first author Wenbo Mao, a doctoral student in Yang’s lab, showed that these unique EPs – specific conditions in systems where extraordinary optical phenomena can occur – can be deployed on conventional sensors to achieve a striking sensitivity to environmental perturbations.Yang and Mao developed an EP-enhanced sensing platform that overcomes the limitations of previous approaches. Unlike traditional methods that require modifications to the sensor itself, their innovative system features an EP control unit that can plug into physically separated external sensors. This configuration allows EPs to be tuned solely through adjustments to the control unit, allowing for ultrahigh sensitivity without the need for complex modifications to the sensor.“We’ve implemented a novel platform that can impart EP enhancement to conventional optical sensors,” Yang said. “This system represents a revolutionary extension of EP-enhanced sensing, significantly expanding its applicability and universality. Any phase-sensitive sensor can acquire improved sensitivity and reduced detection limit by connecting to this configuration. Simply by tuning the control unit, this EP configuration can adapt to various sensing scenarios, such as environmental detection, health monitoring and biomedical imaging.”By decoupling the sensing and control functions, Yang and Mao have effectively skirted the stringent physical requirements for operating sensors at EPs that have so far hindered their widespread adoption. This clears the way for EP enhancement to be applied to a wide range of conventional sensors – including ring resonators, thermal and magnetic sensors, and sensors that pick up vibrations or detect perturbations in biomarkers – vastly improving the detection limit of sensors scientists are already using. With the control unit set to an EP, the sensor can operate differently – not at an EP – and still reap the benefits of EP enhancement.As a proof-of-concept, Yang’s team tested a system’s detection limit, or ability to detect weak perturbations over system noise. They demonstrated a six-fold reduction in the detection limit of a sensor using their EP-enhanced configuration compared to the conventional sensor.&nbsp;“With this work, we’ve shown that we can significantly enhance our ability to detect perturbations that have weak signals,” Mao said. “We’re now focused on bringing that theory to broad applications. I’m specifically focused on medical applications, especially working to enhance magnetic sensing, which could be used to improve MRI technology. Currently, MRIs require a whole room with careful temperature control. Our EP platform could be used to enhance magnetic sensing to enable portable, bedside MRI.”&nbsp;<hr>Mao W, Fu Z, Li Y, Li F, and Yang L. Exceptional-point-enhanced phase sensing.&nbsp;Science Advances, April 5, 2024. DOI:&nbsp;<a href="https://doi.org/10.1126/sciadv.adl5037" target="_blank">https://doi.org/10.1126/sciadv.adl5037</a>This project is supported in part by the Chan Zuckerberg Initiative (CZI). The authors acknowledge the Institute of Materials Science &amp; Engineering (IMSE) at Washington University in St. Louis for the use of instruments, financial support and staff assistance.

Optical sensors have been widely used in various applications, from structural health monitoring to medical diagnosis and imaging. An innovative platform, featuring a control unit operated at an exceptional point (EP), has been developed to enhance the performance of conventional optical sensors. (Credit: Yang Lab)

Lan Yang and her team have developed new plug-and-play hardware to dramatically enhance the sensitivity of optical sensors

Innovative sensing platform unlocks ultrahigh sensitivity in conventional sensors

Our muscles are nature’s perfect actuators — devices that turn energy into motion. For their size, muscle fibers are more powerful and precise than most synthetic actuators. They can even heal from damage and grow stronger with exercise.For these reasons, engineers are exploring ways to power robots with natural muscles. They’ve demonstrated a handful of “biohybrid” robots that use muscle-based actuators to power artificial skeletons that walk, swim, pump, and grip. But for every bot, there’s a very different build, and no general blueprint for how to get the most out of muscles for any given robot design.Now, MIT engineers have developed a spring-like device that could be used as a basic skeleton-like module for almost any muscle-bound bot. The new spring, or “flexure,” is designed to get the most work out of any attached muscle tissues. Like a leg press that’s fit with just the right amount of weight, the device maximizes the amount of movement that a muscle can naturally produce.The researchers found that when they fit a ring of muscle tissue onto the device, much like a rubber band stretched around two posts, the muscle pulled on the spring, reliably and repeatedly, and stretched it five times more, compared with other previous device designs.The team sees the flexure design as a new building block that can be combined with other flexures to build any configuration of artificial skeletons. Engineers can then fit the skeletons with muscle tissues to power their movements.“These flexures are like a skeleton that people can now use to turn muscle actuation into multiple degrees of freedom of motion in a very predictable way,” says Ritu Raman, the Brit and Alex d'Arbeloff Career Development Professor in Engineering Design at MIT. “We are giving roboticists a new set of rules to make powerful and precise muscle-powered robots that do interesting things.”Raman and her colleagues report the details of the new flexure design in a&nbsp;<a href="https://onlinelibrary.wiley.com/doi/full/10.1002/aisy.202300834" target="_blank">paper appearing today</a> in the journal&nbsp;Advanced Intelligent&nbsp;Systems. The study’s MIT co-authors include Naomi Lynch ’12, SM ’23; undergraduate Tara Sheehan; graduate students Nicolas Castro, Laura Rosado, and Brandon Rios; and professor of mechanical engineering Martin Culpepper.<h2>Muscle pull</h2>When left alone in a petri dish in favorable conditions, muscle tissue will contract on its own but in directions that are not entirely predictable or of much use.“If muscle is not attached to anything, it will move a lot, but with huge variability, where it’s just flailing around in liquid,” Raman says.To get a muscle to work like a mechanical actuator, engineers typically attach a band of muscle tissue between two small, flexible posts. As the muscle band naturally contracts, it can bend the posts and pull them together, producing some movement that would ideally power part of a robotic skeleton. But in these designs, muscles have produced limited movement, mainly because the tissues are so variable in how they contact the posts. Depending on where the muscles are placed on the posts, and how much of the muscle surface is touching the post, the muscles may succeed in pulling the posts together but at other times may wobble around in uncontrollable ways.Raman’s group looked to design a skeleton that focuses and maximizes a muscle’s contractions regardless of exactly where and how it is placed on a skeleton, to generate the most movement in a predictable, reliable way.“The question is: How do we design a skeleton that most efficiently uses the force the muscle&nbsp;is generating?” Raman says.The researchers first considered the multiple directions that a muscle can naturally move. They reasoned that if a muscle is to pull two posts together along a specific direction, the posts should be connected to a spring that only allows them to move in that direction when pulled.“We need a device that is very soft and flexible in one direction, and very stiff in all other directions, so that when a muscle contracts, all that force gets efficiently converted into motion in one direction,” Raman says.<h2>Soft flex</h2>As it turns out, Raman found many such devices in Professor Martin Culpepper’s lab. Culpepper’s group at MIT specializes in the design and fabrication of machine elements such as miniature actuators, bearings, and other mechanisms, that can be built into machines and systems to enable ultraprecise movement, measurement, and control, for a wide variety of applications. Among the group’s precision machined elements are flexures — spring-like devices, often made from parallel beams, that can flex and stretch with nanometer precision.“Depending on how thin and far apart the beams are, you can change how stiff the spring appears to be,” Raman says.She and Culpepper teamed up to design a flexure specifically tailored with a configuration and stiffness to enable muscle tissue to naturally contract and maximally stretch the spring. The team designed the device’s configuration and dimensions based on numerous calculations they carried out to relate a muscle’s natural forces with a flexure’s stiffness and degree of movement.The flexure they ultimately designed is 1/100 the stiffness of muscle tissue itself. The device resembles a miniature, accordion-like structure, the corners of which are pinned to an underlying base by a small post, which sits near a neighboring post that is fit directly onto the base. Raman then wrapped a band of muscle around the two corner posts (the team molded the bands from live muscle fibers that they grew from mouse cells), and measured how close the posts were pulled together as the muscle band contracted.The team found that the flexure’s configuration enabled the muscle band to contract mostly along the direction between the two posts. This focused contraction allowed the muscle to pull the posts much closer together — five times closer — compared with previous muscle actuator designs.“The flexure is a skeleton that we designed to be very soft and flexible in one direction, and very stiff in all other directions,” Raman says. “When the muscle contracts, all the force is converted into movement in that direction. It’s a huge magnification.”The team found they could use the device to precisely measure muscle performance and endurance. When they varied the frequency of muscle contractions (for instance, stimulating the bands to contract once versus four times per second), they observed that the muscles “grew tired” at higher frequencies, and didn’t generate as much pull.“Looking at how quickly our muscles get tired, and how we can exercise them to have high-endurance responses — this is what we can uncover with this platform,” Raman says.The researchers are now adapting and combining flexures to build precise, articulated, and reliable robots, powered by natural muscles.“An example of a robot we are trying to build in the future is a surgical robot that can perform minimally invasive procedures inside the body,” Raman says. “Technically, muscles can power robots of any size, but we are particularly excited in making small robots, as this is where biological actuators excel in terms of strength, efficiency, and adaptability.”

MIT engineers have developed a new spring (shown in Petri dish) that maximizes the work of natural muscles. When living muscle tissue is attached to posts at the corners of the device, the muscle’s contractions pull on the spring, forming an effective, natural actuator. The spring can serve as a “skeleton” for future muscle-powered robots. Image: Felice Frankel

New modular, spring-like devices maximize the work of live muscle fibers so they can be harnessed to power biohybrid bots.

Engineers design flexible "skeletons" for soft, muscle-powered robots

Even among people who never miss their yearly medical checkup, very few undergo regular brain examinations. CT scans or magnetic resonance imaging (MRI), which provide a direct view of the state of the brain, utilize equipment that is large, expensive, and requires a high level of specialized expertise in addition to medical knowledge to operate safely. As a result, such examinations are only available at large medical institutions.Murata Manufacturing (Murata) has developed a technology that has the potential to enable ultrasonic scans, which are presently used to view the fetus within the uterus, to be used to view the brain within the cranium. It may be possible, by placing a sheet with a unique structure called an “ultrasound transmission metamaterial” on the skin of the patient’s head, to make the cranium transmissive to ultrasonic waves. If this can be achieved, it is possible that a wider range of medical institutions will be able to perform examinations of the brain relatively easily.Potential fields of application for ultrasound transmission metamaterial are not limited to medicine. In a variety of different areas, such as making automobiles “smarter” and the maintenance and management of social infrastructure, this new technology has the potential to encourage wider utilization of ultrasonic waves. Murata exhibited the ultrasound transmission metamaterial at CEATEC 2023, held at Makuhari Messe from October 17 to 20, 2023. We interviewed Mr. Nishida and Mr. Hussain of the Material Technology Sensor Material Process Development Department, Technology &amp; Business Development Unit of Murata Manufacturing, who were involved in the development of the new technology, about the operating principle behind its unique functionality, as well as possible applications.<h2>Ultrasonic sensors have many useful characteristics, but they can’t detect objects on the other side of a barrier</h2>--What sorts of things does the technology behind the ultrasound transmission metamaterial make possible?Nishida:&nbsp;An ultrasound transmission metamaterial is a material that makes obstructions, which would otherwise prevent ultrasonic waves from passing through, transmissive. As used here, the term “metamaterial” refers to a man-made substance that has functionality for realizing behavior not seen in the natural world, with respect to the propagation of waves of magnetism or sound.Ultrasonic waves are sound waves with a frequency beyond the audible range of the human ear (20 kHz and above). They are used in a variety of areas, ranging from industrial and medical devices to home appliances. Many applications are products that most people will be familiar with, such as fishfinders, ultrasonic cleaners for eyeglasses, and ultrasonic humidifiers. When employed as a sensing medium, ultrasonic waves can be used to detect transparent solid or liquid items or small objects in dark places as well as objects with low reflectance of radio waves. In recent years, ultrasonic sensors have also come into use in automated car parking systems.Ultrasonic waves can be used for many different applications, but one thing limiting the range of uses is that they are unable to pass through barriers made of materials such as metal or resin to reach objects on the other side. When ultrasonic waves impinge on a substance with an acoustic impedance significantly different from that of the propagation medium (air when detecting objects in the atmosphere), most of them are reflected back and very few pass through. “Acoustic impedance” is an index of how easy it is for sound to be conveyed. It is a small value in the case of air, in which molecules are distributed thinly, and a high value in the case of dense substances such as metal or resin. This is why the boundary between air and a solid barrier is not transmissive to ultrasonic waves.&nbsp; Note: For a detailed description of “acoustic impedance,” click <a href="https://www.murata.com/en-eu/products/sensor/ultrasonic/overview/basic/nature?intcid1=mar_art_xxx_tac_xxx_tac-ows" target="_blank">here</a>.The ultrasound transmission metamaterial developed by Murata incorporates a resonating mechanism utilizing a spring-mass resonator structure. Placed on top of the material constituting the obstruction, it reduces the difference in acoustic impedance, thereby increasing the transmissivity to ultrasonic waves.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyNzYxNTk3OTYwLWltZzAwMDFhLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib"><h2 id="isPasted">Ultrasound transmission metamaterial that enables ultrasonic waves to pass through substances</h2>--Specifically, what functionality did you achieve when you created a prototype of the ultrasound transmission metamaterial?Hussain:&nbsp;The structure of the ultrasound transmission metamaterial developed by Murata consists of “tiny unit cells,” each composed of a weight and a spring, arrayed regularly on a backing sheet (Figure 1). It is designed so that, by adjusting the configuration and size of the weights and springs, the unit cells can act as spring-mass resonators when impinged upon by ultrasonic waves. The unit cells resonate perpendicularly to the direction of the impinging ultrasonic waves, causing an obstruction with a greatly different acoustic impedance to become transmissive and allowing the ultrasonic waves to propagate efficiently.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyNzYxNjMxOTI4LWltZzAwMDJiLWVuLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib">Figure 1: Figure showing how the prototype of “ultrasound transmission metamaterial” created by Murata increases ultrasonic permeability and schematic diagram of unit cellTo create the prototype, a 3D printer was used to form tiny unit cells on a stainless steel plate 1 mm thick. This was then immersed in water and ultrasonic waves at a frequency of 500 kHz were directed toward it from a transmitter. The receiver on the other side indicated that we had succeeded in achieving 60% ultrasonic transmissivity. This technology can enable ultrasonic waves to pass through more than just stainless steel plates. It can be applied to a variety of different materials if we can design unit cells matched to the difference in acoustic impedance between the obstruction and the transmission medium.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyNzYxNjU1ODUyLWltZzAwMDMuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib">Prototype and test rig during verification of effectiveness<h2 id="isPasted">Using an ultrasonic scan to examine a brain encased in the cranium</h2>--What sorts of applications do you envision for the ultrasound transmission metamaterial you have developed?Nishida:&nbsp;First of all, we envision its application as a material used in medical examinations. In the medical field, ultrasonic scans are used as an examination method to reveal important information that cannot be obtained using X-ray, CT, or MRI scans. A particular advantage of ultrasound scans is that they produce video output showing the movement of the affected part of the body. In addition, unlike examination method such as CT scans that employ X-rays, there is no danger of overexposure to radiation.<figure><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyNzYxNzMyNTYwLTE3MTI3NjE3MzI1NjAucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" width="601" height="539" alt="Image of using an ultrasonic scan to examine a brain encased in the cranium" class="fr-fic fr-dii"><figcaption> </figcaption></figure>But even though ultrasonic scans provide these benefits, ultrasonic waves are not able to pass through bone and can therefore not be used to examine organs or structures that are encased in bone. This means that ultrasonic scans cannot be used to examine the brain, which is encased in the cranium.The ultrasound transmission metamaterial may make it possible to perform ultrasonic scans of the brain. It is our hope that this will enable detailed examinations to be performed easily, even at smaller medical facilities, while minimizing the burden on the patient.<h2>Installing ultrasonic sensors without detracting from the design attractiveness of automobiles</h2>Hussain:&nbsp;Ultrasonic sensors are used in automotive parking-assist systems, but our new technology will make it possible for them to be installed in places where they are not exposed on the outside of the vehicle. Up to now, it has been necessary to install automotive ultrasonic sensors on the exterior surface of the vehicle’s body. If they are under a cover of some kind, the ultrasonic waves are not able to pass through.<figure><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyNzYxNzMyNTE5LTE3MTI3NjE3MzI1MTkucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" width="600" height="377" alt="Image of installing ultrasonic sensors without detracting from the design attractiveness of automobiles" class="fr-fic fr-dii"><figcaption> </figcaption></figure>There is no doubt that in the near future automobiles will need to have many different kinds of sensors installed in various places on the vehicle in order to enable autonomous driving functionality. It is possible that for many consumers who love cars, the value as products of models with a large number of unsightly exposed sensors on them will drop. Also, installing the sensors in exposed positions on the body reduces their durability. For this reason, there is demand for technology that will enable ultrasonic sensors to be installed in a way that does not detract from cosmetic appearance or reliability. By using an ultrasound transmission metamaterial, it will become possible to install ultrasonic sensors in places like inside a car’s bumpers.<h2 id="isPasted">Noncontact inspection of the interior portion of underwater cables within the cladding</h2>Nishida:&nbsp;The technology can also be applied in the maintenance and management of underwater cables used for things like long-distance communication and offshore wind power generation. Maintenance and management to ensure the stable operation of underwater cables requires inspection not only of the exterior, but also of the interior portion of the cable inside the cladding. Nevertheless, up to now, there has been no way to check the status of the interior of cables encased in cladding.<figure><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEyNzYxODA2MzE5LTE3MTI3NjE4MDYzMTkucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" width="600" height="531" alt="Image of enabling noncontact ultrasonic inspection" class="fr-fic fr-dii"><figcaption id="isPasted">Enabling noncontact ultrasonic inspection</figcaption><figcaption> </figcaption></figure>Adding an ultrasound transmission metamaterial to the cladding of underwater cables would make it possible to inspect the cable interior without making physical contact, by using underwater drones equipped with ultrasonic sensors or by lowering such sensors from ships. This has the potential to reduce the burden associated with inspections of underwater objects in seas or rivers.<h2>Ultrasound transmission metamaterial that expands the range of places where ultrasonic waves can be used</h2>Hussain:&nbsp;In the businesses involved in implementing the newly developed technology in society, I hope we can create a system enabling the design of unit cells optimized for places where ultrasound transmission metamaterials are used, and complete and make available solutions that provide the required results.Nishida:&nbsp;The three application examples we have described are only some of the candidates we can envision at this point in time. The unique technological characteristics of ultrasound transmission metamaterial will surely expand the range of places where ultrasonic waves can be used and pave the way for many more applications we haven’t even thought of yet. In addition to sensors, applications using ultrasonic waves to process or clean materials may give rise to additional value in the application of the technology we developed.We still have a lot of work to do refining the new technology for use in actual applications. At the same time, we are working to pave the way for innovative new applications and to attract a wide array of business partners to help with the refinements. If you think your company would be interested in joining us in this effort, please feel free to contact us.<hr id="isPasted"><img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1713769861492-1713769861492.png" class="fr-fic fr-dii">If you have any questions based on this article that you would like to discuss with an expert at Murata, don't hesitate to reach out. There's an entire team ready to support you with your question.<a href="https://www.murata.com/en-eu/contactform?&Detail=Wevolver%20request" target="_blank" rel="nofollow" class="button-main-action">GET IN TOUCH</a>

Murata Manufacturing (Murata) has developed a technology that has the potential to enable ultrasonic scans, which are presently used to view the fetus within the uterus, to be used to view the brain within the cranium.

"Ultrasound Transmission Metamaterial" that Expands the Range of Places where Ultrasonic Sensors Can Be Used to Include Medicine and Automobiles

In this episode, we discuss a breakthrough from ETH Zurich to mimic natural foot signals to the brain using state of the art neuroprosthetics. 

Podcast: Neuroprosthetics: The Next Step Towards Limb Reconstruction

Small wearable or implantable electronics could help monitor our health, diagnose diseases, and provide opportunities for improved, autonomous treatments. But to do this without aggravating or damaging the cells around them, these electronics will need to not only bend and stretch with our tissues as they move, but also be soft enough that they will not scratch and damage tissues.Researchers at Stanford have been working on skin-like, stretchable electronic devices for over a decade. In a paper published March 13 in Nature, they present a new design and fabrication process for skin-like integrated circuits that are five times smaller and operate at one thousand times higher speeds than earlier versions. The researchers demonstrated that their soft integrated circuits are now able to drive a micro-LED screen and detect a braille array that is more sensitive than human fingertips.“We’ve made a significant leap forward. For the first time, stretchable integrated circuits are now small enough and fast enough for many applications,” said <a href="https://mandrillapp.com/track/click/30855492/profiles.stanford.edu?p=eyJzIjoiOVAtVVZYVEltMTAyQXVpZ2ppSmFNd3RkQjNvIiwidiI6MSwicCI6IntcInVcIjozMDg1NTQ5MixcInZcIjoxLFwidXJsXCI6XCJodHRwczpcXFwvXFxcL3Byb2ZpbGVzLnN0YW5mb3JkLmVkdVxcXC96aGVuYW4tYmFvXCIsXCJpZFwiOlwiMGM2YWMxYWU5MTg4NGZjYWFjMzI1ZDc2M2MyZDhhODdcIixcInVybF9pZHNcIjpbXCJkMGY0ZGMxYjBmMDE3OTkzNjhmOGE4NzJlMmViNzQ3ZTFjZmNmMjBkXCJdfSJ9" data-extlink="" target="_blank">Zhenan Bao</a>, a K. K. Lee Professor in Chemical Engineering at Stanford and senior author on the paper. “We hope that this can make wearable sensors and implantable neural and gut probes more sensitive, operate more sensors, and potentially consume less power.”<h2>Flexible, stretchable, and functional</h2>The core of the circuits are stretchable transistors made from semiconducting carbon nanotubes and soft elastic electronic materials developed in Bao’s lab. Unlike silicon, which is hard and brittle, the carbon nanotubes sandwiched between elastic materials have a fishnet-like structure that allows them to continue to function while they stretch and deform. The transistors and circuits are patterned onto a stretchable substrate, along with stretchable semiconductor, conductor, and dielectric material.“This is many years of material and engineering development,” Bao said. “We not only needed to develop new materials, but we also needed to develop the circuit design and the fabrication process to make the circuits. There are many layers stacked together and if one layer doesn’t work, we have to restart everything from scratch.”In one demonstration of their new stretchable electronics design, the researchers were able to fit more than 2,500 sensors and transistors into a square centimeter, creating an active-matrix tactile array over ten times more sensitive than human fingertips. The researchers showed that the sensor array can detect the locations and orientation of tiny shapes or recognize whole words in Braille.“With Braille, you usually sense one letter at a time,” said <a href="https://mandrillapp.com/track/click/30855492/baogroup.stanford.edu?p=eyJzIjoiQWFWMU9jM2VqYXZMR2g5TFVfMnRPcTE4cGxnIiwidiI6MSwicCI6IntcInVcIjozMDg1NTQ5MixcInZcIjoxLFwidXJsXCI6XCJodHRwczpcXFwvXFxcL2Jhb2dyb3VwLnN0YW5mb3JkLmVkdVxcXC9wZW9wbGVcXFwvZG9uZ2xhaS16aG9uZ1wiLFwiaWRcIjpcIjBjNmFjMWFlOTE4ODRmY2FhYzMyNWQ3NjNjMmQ4YTg3XCIsXCJ1cmxfaWRzXCI6W1wiNTgyODY0ZTdiMWU3NWU4ZGRiOWM5OWIyOTI5YWU1YTFiODU3MDZiYVwiXX0ifQ" data-extlink="" target="_blank">Donglai Zhong</a>, a postdoctoral researcher in Bao’s lab and co-first author on the paper. “With such a high resolution, you could sense a whole word, or potentially a whole sentence, with just one touch.”The researchers also used their stretchable circuits to drive a micro-LED display with a refresh rate of 60 Hz, which is the typical refresh rate of a computer or TV screen. Previous versions of the stretchable circuits weren’t fast enough at small sizes to generate enough current to accomplish this.“We’re really excited about these performance improvements because they enable us to do a lot of new things,” said <a href="https://mandrillapp.com/track/click/30855492/baogroup.stanford.edu?p=eyJzIjoia1V0NTdYUFNUVGxncTZEZFg0RWh1MGRnRDg0IiwidiI6MSwicCI6IntcInVcIjozMDg1NTQ5MixcInZcIjoxLFwidXJsXCI6XCJodHRwczpcXFwvXFxcL2Jhb2dyb3VwLnN0YW5mb3JkLmVkdVxcXC9wZW9wbGVcXFwvY2FuLXd1XCIsXCJpZFwiOlwiMGM2YWMxYWU5MTg4NGZjYWFjMzI1ZDc2M2MyZDhhODdcIixcInVybF9pZHNcIjpbXCI4MTliZDk3YzY5NzMxMjg0ZjcwMDgwNTY4MDdhZjFjOGNlYmE0ZTExXCJdfSJ9" data-extlink="" target="_blank">Can Wu</a>, a postdoctoral researcher in Bao’s lab and co-first author on the paper. “Preliminary results demonstrate that our transistor can be used to drive commercial displays commonly used in computer monitors, for example. And for biomedical applications, a high-density, soft, and conformable sensing array could allow us to sense human body signals, such as from our brains and muscles, at a large scale and fine resolution. This could lead to next-generation brain-machine interfaces that are both high-performance and biocompatible.”<h2>Soft circuits for the future</h2>The researchers intentionally developed materials and processes that could work with existing fabrication tools, so that the circuits could make the jump to commercial manufacturing more easily. Their process relies on fabrication techniques similar to what is currently used for making display screens, although the materials involved are entirely different. Manufacturers wouldn’t be able to make these circuits without some additional fine-tuning, but the tools are already in place, Bao said.Of course, there are more hurdles before these stretchable and soft integrated circuits can be ready for commercialization. Body and tissue movement can still cause some variation in the electrical characteristics of the circuits – Bao and her colleagues are working on new designs that could reduce these effects – and the devices will need some sort of soft moisture protection before they can be put to use.“There are still challenges for the future of this technology, but these recent developments open up some very exciting biomedical applications for wearable and implantable electronics,” Bao said. “And it also has applications in soft robotics, giving robots a sensing functionality that approaches that of humans and makes them safer for people to work with.”Bao is a member of&nbsp;<a href="https://biox.stanford.edu/" data-extlink="" target="_blank">Stanford Bio-X</a>, the&nbsp;<a href="https://med.stanford.edu/cvi.html" data-extlink="" target="_blank">Stanford Cardiovascular Institute</a>, the&nbsp;<a href="https://humanperformance.stanford.edu/" data-extlink="" target="_blank">Wu Tsai Human Performance Alliance</a>, the&nbsp;<a href="https://neuroscience.stanford.edu/" data-extlink="" target="_blank">Wu Tsai Neurosciences Institute</a>, and the&nbsp;<a href="https://med.stanford.edu/mchri.html" data-extlink="" target="_blank">Maternal &amp; Child Health Research Institute</a>; an affiliate of the&nbsp;<a href="https://energy.stanford.edu/" data-extlink="" target="_blank">Precourt Institute for Energy</a>&nbsp;and the&nbsp;<a href="https://woods.stanford.edu/" data-extlink="" target="_blank">Stanford Woods Institute for the Environment</a>; and a faculty fellow of&nbsp;<a href="https://chemh.stanford.edu/" data-extlink="" target="_blank">Sarafan ChEM-H</a>. Bao is an investigator of CZ-Biohub-San Francisco and an innovation investigator of Arc Institute.Other Stanford co-authors of this research include research scientist Jeffrey B.-H. Tok; postdoctoral researchers Yuanwen Jiang (Co-first-author), Min-gu Kim, Chien-Chung Shih, Jian-Cheng La, Chuanzhen Zhao, Shiyuan Wei, Xiaozhou Ji, Yi-Xuan Wang, Chengyi Xu, Naoji Matsuhisa, Yusheng Lei, Deya Liu, Song Zhang, and Yuto Ochiai; and doctoral students Yujia Yuan, Yuya Nishio, Weichen Wang, Theodore Z. Gao, Yu Zheng, Zhiao Yu, Huaxin Gong, and Shuhan Liu.

Intrinsically stretchable transistors and integrated circuits under large deformation after being released from the supporting substrate. | Image courtesy of Donglai Zhong, Jiancheng Lai, and Yuya Nishio of the Bao Group

Stanford researchers have developed soft integrated circuits that are powerful enough to drive a micro-LED screen and small enough to read thousands of sensors in a single square centimeter.

Smaller, more powerful stretchable electronics for wearables and implantables

In this episode, we discuss a novel sticker capable of monitoring the health of organs in real time allowing for more successful organ transplants and catching signs of diseases earlier than ever!

Podcast: Sticker to Monitor Your Internal Organs

SPT Vilecon is a fully integrated provider of development and manufacturing services to the medical device industry, working at the intersection of design, development, and manufacturing to allow customers to move a new product from concept to commercialization, and with inhouse tool building in place to ensure shortest possible lead-times. Certified according to ISO 13485, the European standard governing medical device manufacturing, they provide product development support as well as injection molding and other manufacturing services to a large number of companies in northern Europe.Recognizing that speed is always of the essence, SPT decided to implement Nexa3D Freeform Injection Molding. The goal was to help customers shorten times-to-market on complex medical devices in demanding medical-grade materials and to expand on the range of materials that can be quickly and reliably used in prototyping and early device test manufacturing.<h2 id="isPasted">The challenge</h2><h3>Medical device development requires production-grade prototypes</h3><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEwMTI5MTgzNDEyLW1lZGljYWwtZGV2aWNlLXByb2R1Y3Rpb24tZ3JhZGUtcHJvdG90eXBpbmctMTgwMHgxMzM5LmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib"> Medical device manufacturers face rigorous regulatory requirements when introducing new devices into the market. A medical device needs to be safe and efficient to use for the intended purpose, and it is the job of the manufacturer to demonstrate that a given device meets these essential requirements. To do so, manufacturers must develop elaborate test protocols that evaluate every aspect of device manufacturing and usage, and they must ensure that tests are carried out in a way that accurately represents the conditions that apply for the manufacturing and usage of the finished medical device. The later these tests are carried out, the more severe the consequences are if a test fails. Medical device companies are constantly on the lookout for tools and methods that help them improve early-stage device testing to reduce development risks and costs of rework.SPT Vilecon often works with Silicones, a group of materials that are heavily used in the medical device industry due to their excellent chemical resistance, mechanical performance and biocompatibility. However, silicone parts are notoriously difficult to prototype and test, since most grades need to be injection-molded to achieve their full performance.<blockquote id="isPasted">“Freeform Injection Molding has enabled us to dramatically accelerate the delivery of production-grade prototypes and low-volume productions in challenging materials and designs.”– Bjarne Andersen, CEO, STP Vilecon</blockquote><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEwMTI5Mjk4NTI5LTE3MTAxMjkyOTg1MjkucG5nIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" class="fr-fic fr-dib"><h2 id="isPasted">The solution</h2><h3>3D printed injection mold tooling allows early verification, new applications</h3><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEwMTI5MzQwMDQzLXhpcC1kZXNrb3AtM2QtcHJpbnRlci1maW0tbWVkaWNhbC0xODAweDE2NTUuanBnIiwiZWRpdHMiOnsicmVzaXplIjp7IndpZHRoIjo5NTAsImZpdCI6ImNvdmVyIn19fQ==" style="width: 100%px;" class="fr-fic fr-dib"> To meet customer demands for rapid prototyping of silicones, and other complex medical-grade materials, SPT Vilecon wanted a prototyping platform that would integrate seamlessly with their existing tool-building and injection molding capabilities. Other key requirements included biocompatibility, compatibility with the wide range of thermoplastics and silicones already in use, as well as design freedom for complex part prototyping. In the end, they decided to implement Nexa3D’s XiP desktop system and Freeform Injection Molding with xMOLD resin. This compact and highly versatile platform was the only alternative that met all the key requirements, while at the same time enabling SPT Vilecon to expand into new domains based on metal and ceramic injection molding.<h2 id="isPasted">The benefits</h2><h3>2-day development and verification of complex silicone parts</h3><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEwMTI5MzU1MjczLXNwdC12aWxlY29uLTNkLXByaW50ZWQtdG9vbHMtMTgwMHgxMjAwLmpwZyIsImVkaXRzIjp7InJlc2l6ZSI6eyJ3aWR0aCI6OTUwLCJmaXQiOiJjb3ZlciJ9fX0=" style="width: 100%px;" class="fr-fic fr-dib"> With Freeform Injection Molding, SPT Vilecon was able to offer a customer developing an intravenous silicone product, early design and material verification by utilization of 3D printed tools.Early Verification: The use of 3D-printed xMOLD tooling enabled the customer to obtain injection-molded silicone parts in a medical-grade silicone within two days, and to verify key design and performance aspects.Rapid iterations: At the same time, important design input was collected from the first tests, which could be integrated in a second iteration that took only a couple of hours to complete. In comparison, the conventional metal tooling that would normally be needed for this kind of verification would have taken more than six weeks to design and procure, and the adjustments needed for the second iteration would have taken the inhouse tool-shop a week to complete.Cost and time savings: The costs of the 3D-printed silicone molds for the first and second iterations were less than EUR 2.000 combined. And the two-day design cycle was more than 90% faster than the speed achievable with conventional metal tooling.Seamless scalability: Based on the design input collected from the first two iterations, the design of the silicone part was approved and the manufacturing of a metal tool could be initiated with full confidence of part moldability and performance. The collected design input and learnings enabled the inhouse tool-shop to produce the metal tooling within 4 weeks, with no iterations needed in the final tool.<h2 id="isPasted">Customer Impact</h2><h3>Compliance with project timeline, budget ensured through early verification</h3><img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzEwMTI5Mzc3Mzk2LW1lZGljYWwtZGV2aWNlLW1hbnVmYWN0dXJlZC0zZC1wcmludGVkLTEyMDB4MTgwMC5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 100%px;" class="fr-fic fr-dib"> Medical device manufacturers face strong pressures to bring new and innovative products to market. Robust and valid prototyping and verification is key to minimize costs, time and risks associated with the development. By implementing Freeform Injection Molding, SPT Vilecon has created a new toolbox for medical device companies seeking to accelerate their innovation and obtain early verification of part performance and moldability.Using the XiP with Freeform Injection Molding, a medical device manufacturer was able to save 6 weeks, and 87% of prototyping investments, while at the same time removing a challenging silicone component from the critical path of product development.SPT Vilecon has been able to start expanding the range of injection mold prototyping into the domains of silicone, metal and ceramic injection molding, to provide medical device manufacturers with an even wider selection of product development and verification services.

Medical device manufacturer adopts Nexa3D’s FIM process to shorten times-to-market on complex medical devices

SPT Vilecon Accelerates Medical Device Development with Freeform Injection Molding

Fat tissue holds the key to 3D printing layered living skin and potentially hair follicles, according to researchers who recently harnessed fat cells and supporting structures from clinically procured human tissue to precisely correct injuries in rats. The advancement could have implications for reconstructive facial surgery and even hair growth treatments for humans.&nbsp;The team’s findings published today (March 1) in&nbsp;<a href="https://doi.org/10.1016/j.bioactmat.2023.10.034" target="_blank">Bioactive Materials</a>. The U.S. Patent and Trademark Office granted the team a patent in February for the bioprinting technology it developed and used in this study.&nbsp;“Reconstructive surgery to correct trauma to the face or head from injury or disease is usually imperfect, resulting in scarring or permanent hair loss,” said Ibrahim T. Ozbolat, professor of engineering science and mechanics, of biomedical engineering and of neurosurgery at Penn State, who led the international collaboration that conducted the work. “With this work, we demonstrate bioprinted, full thickness skin with the potential to grow hair in rats. That’s a step closer to being able to achieve more natural-looking and aesthetically pleasing head and face reconstruction in humans.”While scientists have previously 3D bioprinted thin layers of skin, Ozbolat and his team are the first to intraoperatively print a full, living system of multiple skin layers, including the bottom-most layer or hypodermis. Intraoperatively refers to the ability to print the tissue during surgery, meaning the approach may be used to more immediately and seamlessly repair damaged skin, the researchers said. The top layer — the epidermis that serves as visible skin — forms with support from the middle layer on its own, so it doesn’t require printing. The hypodermis, made of connective tissue and fat, provides structure and support over the skull.“The hypodermis is directly involved in the process by which stem cells become fat,” Ozbolat said. “This process is critical to several vital processes, including wound-healing. It also has a role in hair follicle cycling, specifically in facilitating hair growth.”The researchers started with human adipose, or fat, tissue obtained from patients undergoing surgery at Penn State Health Milton S. Hershey Medical Center. Collaborator Dino J. Ravnic, associate professor of surgery in the Division of Plastic Surgery at Penn State College of Medicine, led his lab in obtaining the fat for extraction of the extracellular matrix — the network of molecules and proteins that provides structure and stability to the tissue — to make one component of the bioink.Ravnic’s team also obtained stem cells, which have the potential to mature into several different cell types if provided the correct environment, from the adipose tissue to make another bioink component. Each component was loaded into one of three compartments in the bioprinter. The third compartment was filled with a clotting solution that helps the other components properly bind onto the injured site.“The three compartments allow us to co-print the matrix-fibrinogen mixture along with the stem cells with precise control,” Ozbolat said. “We printed directly into the injury site with the target of forming the hypodermis, which helps with wound healing, hair follicle generation, temperature regulation and more.”They achieved both the hypodermis and dermis layers, with the epidermis forming within two weeks by itself.“We conducted three sets of studies in rats to better understand the role of the adipose matrix, and we found the co-delivery of the matrix and stem cells was crucial to hypodermal formation,” Ozbolat said. “It doesn’t work effectively with just the cells or just the matrix — it has to be at the same time.”They also found that the hypodermis contained downgrowths, the initial stage of early hair follicle formation. According to the researchers, while fat cells do not directly contribute to the cellular structure of hair follicles, they are involved in their regulation and maintenance.“In our experiments, the fat cells may have altered the extracellular matrix to be more supportive for downgrowth formation,” Ozbolat said. “We are working to advance this, to mature the hair follicles with controlled density, directionality and growth.”According to Ozbolat, the ability to precisely grow hair in injured or diseased sites of trauma can limit how natural reconstructive surgery may appear. He said that this work offers a “hopeful path forward,” especially in combination with other projects from his lab involving printing bone and investigating how to match pigmentation across a range of skin tones.“We believe this could be applied in dermatology, hair transplants, and plastic and reconstructive surgeries — it could result in a far more aesthetic outcome,” Ozbolat said.“With the fully automated bioprinting ability and compatible materials at the clinical grade, this technology may have a significant impact on the clinical translation of precisely reconstructed skin.”Ravnic and Ozbolat also are affiliated with the Huck Institutes of the Life Sciences and the Penn State Cancer Institute. Ozbolat has additional affiliations with the Penn State Materials Research Institute and the Department of Medical Oncology at Cukurova University in Turkey, where he is currently on sabbatical leave. Other contributors include Yogendra Pratap Singh, postdoctoral scholar, and Mecit Altan Alioglu, graduate student, both in the Penn State Department of Engineering Science and Mechanics; Youngnam Kang and Miji Yeo, both researchers, and Irem Deniz Derman, graduate student, in the Huck Institutes of the Life Sciences; Yang Wu, Harbin Institute of Technology in China; and Jasson Makkar and Ryan R. Driskell, College of Veterinary Medicine at Washington State University. Kang, Yeo, Singh, Alioglu and Derman also are affiliated with Penn State Department of Engineering Science and Mechanics.

Miji Yeo, a postdoctoral researcher at Penn State, checks the bioink cartridges on a 3D printer developed to intraoperatively print layers of skin. Credit: Michelle Bixby/Penn State. All Rights Reserved.

Bioengineered advancement may have implications for more natural-looking reconstructive surgery outcomes, according to international research team

3D-printed skin closes wounds and contains hair follicle precursors

<h2 id="isPasted">What is silver/silver chloride ink?</h2>‍Silver/silver chloride (Ag/AgCl) is a conductive ink typically used to print electrodes for biomedical applications. It’s a non-toxic, environmentally friendly ink with stable electrochemical potential used to create disposable on-skin medical electrodes for biosensors, like "ECG, EEG and TENS electrodes; defibrillator pads; transdermal drug delivery; biomedical sensors and reference electrodes," according to <a href="https://www.creativematerials.com/products/ag-agcl-inks/" target="_blank">Creative Materials</a>.&nbsp;‍<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1709524616616-63d022dacfb6e86a1a3cf1c4_ffhgM2WgWmVRDuIv4GtMPtOgJnNsHrpU0DlhQb2hw9DhzCZ4C7IujXkmI6-Wb1oQkcFbDkFukxQI-6qOCSdGzc-RG3ihBfYeMomcrtZXFV6dX66qBWO6I56fjNV7IngcIVg4ZVpc3em72_ZUQ7XEEeOsDnoXYJ3UkXIu4GSpT1uTJ1njEsNQKtcxJaKNC.png" style="width: 100%px;" class="fr-fic fr-dib">Source: Henkel<h3 id="isPasted">Features:</h3><ul><li>Silver-to-silver chloride ratios can be adjusted and blended to achieve different resistance values and sensitivity levels.&nbsp;</li><li>The ink has a smooth surface finish with excellent adhesion and crease resistance when printed onto polyester and plastic substrates.&nbsp;</li><li>Silver/silver chloride is compatible with screen printing and direct-ink-writing printing technology.&nbsp;</li></ul><h2>Smart health patches</h2>‍Used in both healthcare and athletics applications, smart health patches deliver new capabilities in monitoring. These devices can continuously measure heart rate, brain activity, movement, and other body functions. <a href="https://www.quad-ind.com/smart-health-patches-to-run-smart/" target="_blank">Quad Industries’ Smart Health Patch</a>, designed to optimize training for ultra-runners, is made using Henkel’s silver/silver chloride ink.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1709524652661-63d022daa5cbee3ab018e3e7_8VgrqoubKIfwaL1zITpxMMjBjwZ0pwQdx2p_UCyq48yZIDh9jqqb281s3xO3BjQ7xTJO1oM0xUcUoKoQ6506xXmB2AnVlUENl_QzrSiBiDSWsE25qMLNrOtCmqt1c8hxKm-xZMRmZoxMabvNRQA6Udn9Q6RByf0cqbC_Dy22HfbQWYy4S7Tu8SvzcJjw9.png" style="width: 100%px;" class="fr-fic fr-dib">Source: Quad Industries<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1709524667591-63d022dac9c95f5daebb1936_7x7-GMmj24mLom3wqW-nHmMi9PeRUDPwS6Pv5tYsxw_QONplpV8Uyxc6qzd6FJCo3t4G_uNybUwFGiJohdDlYNlrqbXxN0Dv3g1kujpKAT8hPn5BLnvSYClXC0DZIMi8kvIL44HJyqEZwq3CgivP2w_SNr8UElf52dxJI3B_k1N1qiwnP6yNkXgmyRzOe.png" style="width: 100%px;" class="fr-fic fr-dib"><figure data-rt-type="image" data-rt-align="center" id="isPasted"><figcaption>Source: Quad Industries‍</figcaption></figure>‍Silver/silver chloride ink is also used to print glucose sensors for continuous glucose monitoring (CGM) patches like Freestyle Libre.CGM patches are being widely adopted for diabetes management. Rather than pricking a finger several times a day to monitor glucose levels, the CGM continuously measures glucose in the blood and interfaces with a reader device or smartphone app. This allows patients to monitor glucose levels throughout the day and refine the timing for their insulin injections.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1709524688181-63d022da3ae9a36f914066d5_hHSjbJgZWS36H1qokZ_5LN2coCJiIs7H9b7Uw6TUm0o7Qbss4LCqngtZB53W-wdG_sMiMR7KnUMKSRcuX3OhSHY_ngYl7SoPJEe1ZVD_LTrvMQfALXzmxpZAVSwQMxAkHLrVb_SZ0MxJqfYS9fmmN_cH8CSOwUOq1YLmYLEZqfyrDEwgtp1lhSBGSFLoV.png" style="width: 100%px;" class="fr-fic fr-dib">Source: Healthline<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1709524702228-63d022da3916c36e5646942d_QdXGhsRpN4wtDyT6VosSkgxf0n4hxX7QICaxkDGbyBOM1Ar0t7ehDpr8ZQoIHzbhKxWRzY8_0G1bBz20I3Yi61Pf0pI0vCZ-6Bd6a7TGwEZp6waSXE0_Ascb-h8PVZQsQcwqcIt5-SUFVGauo6chHPNjqTfZa3hUNWCJfkaXF0WyMdRWn0TQdMiYLySC.jpeg" style="width: 100%px;" class="fr-fic fr-dib">Source: Advanced Technologies and Polymer Materials for Surgical Sutures<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1709524715190-63d022dad7285c542dc110f7_YSW1DtYARgBxTI1OcJYkuL_bHjR4eAI01NARpWowdleL1PdML6EBfQ_ksZ3d9jS4o9G6m6beeDeroNPsSs1OxRiOhx7wZA7-ws935lrFJZpgSVoHFMf49r1TYDTgE-eP-sOOrhR3C15nlwi19GzLEiqP-VQNR-vhQo7fOW3MlwK5SiBN7Uh-ltI3qhHSP.png" style="width: 100%px;" class="fr-fic fr-dib">Source: HenkelIn recent years, CGMs also have become a tool for athletic performance. Endurance athletes use CGMs to monitor for dips in glucose during training, and then methodically dial in their fuel strategy and nutrition plan accordingly. The <a href="https://www.supersapiens.com/" target="_blank">Supersapiens</a> glucose monitoring system is being leveraged by athletes like Crossfit Games champion Samantha Briggs, olympic triathlon gold medalist Kristian Blummenfelt, and endurance obstacle course world champion Ryan Atkins.&nbsp;<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1709524734463-63d022dabc5f8813d838b2d8_x7tSiD3dwvioNowEvZUasv-THGBtHupPy1ikaI29n8xyFH_LLcNtG0P3YC-ZncS2A82C9caDVwLeK1aHPlWYoN5ex_AI4YwzcVdOPMuK5d9AG7Os9XvLz1v68Xk56Uu_Q_DKjbceQ84tf8ZoTsFuLDn4GvyU6fWrkS92eL7nrIRSUA7ehMEgPfYecPW2F.png" style="width: 768px;" class="fr-fic fr-dib">Source: SupersapiensSilver/silver chloride ink can also be paired with TPU used to print stretchable interconnections for constructing <a href="https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6163896/" target="_blank">medical sensor textiles</a> and <a href="https://journals.sagepub.com/doi/abs/10.1177/00405175211005039" target="_blank">smart textile garments</a>. Commercialization has been limited due to lack of cost-effective, standard fabrication processes that can be applied to a large variety of fabrics, but companies like <a href="https://softmatter.io/" target="_blank">Softmatter</a> and <a href="https://www.memtronik.com/printed-electronics/smart-clothing/" target="_blank">Memtronik</a> now offer customized smart-garment design and fabrication.<hr><h2>I want this ink. Where do I start?</h2><h4>‍Henkel Adhesive Technologies</h4>If you work in the engineering world, you’re probably familiar with Loctite, a line of products by Henkel Adhesive Technologies. Loctite EDAG 7019 E&amp;C is a silver/silver chloride conductive ink, formulated to provide excellent adhesion to the wide variety of substrates used in the manufacture of electrically conductive medical devices.&nbsp;Read the datasheet here: <a href="https://tds.henkel.com/tds5/Studio/ShowPDF/?pid=EDAG%207019%20EC&format=MTR&subformat=HYS&language=EN&plant=WERCS&authorization=2" target="_blank">LOCTITE EDAG 7019 E&amp;C Technical Data Sheet </a>Henkel also sells a&nbsp;<a href="https://print-your-electronics-with-loctite.com/LOCTITE-SENSOR-DEMONSTRATOR" target="_blank">Loctite sensor demonstrator kit</a> with twelve dry adhesive electrodes for medical research and technical material validation. Henkel Adhesive Technologies have developed a wide portfolio of innovative solutions in adhesives, sealants, inks, and functional coatings.&nbsp;<h4>Dupont</h4>‍Another option is Dupont 5874 silver/silver chloride, which is designed for screen printing on polyester, and is suitable for a wide variety of biomedical applications. Dupont is an industry leader in materials development, combining scientific and applications development expertise to accelerate innovation. Read the datasheet here: <a href="https://www.dupont.com/content/dam/dupont/amer/us/en/mobility/public/documents/en/EI-10086-DuPont-5874-Ag_AgCI-Composition-Data-Sheet.pdf" target="_blank" data-lf-fd-inspected-kn9eq4roawkarlvp="true">Dupont 5874 silver/silver chloride composition for screen printing</a><h4>Kayaku Advanced Materials‍</h4>Kayaku Advanced Materials also offers a silver/silver chloride conductive ink, designed for screen printing medical EEG and EKG sensors. Kayaku develops and manufactures innovative specialty materials to push the latest innovation trends. Read the datasheet here: <a href="https://kayakuam.com/wp-content/uploads/2020/03/agcl-675-silver-chloride-ink.pdf" target="_blank" data-lf-fd-inspected-kn9eq4roawkarlvp="true">AGCL-675 SILVER/SILVER CHLORIDE INK&nbsp;</a>

‍Silver/silver chloride (Ag/AgCl) is a conductive ink typically used to print electrodes for biomedical applications.

Materials Feature: Silver or Silver Chloride Ink

In this episode, we discuss the shortcomings of previous attempts at making flexible wearable sensors and how researchers at CalTech have addressed them to create high performance stress sensor stickers.

Stress Sensing Stickers

After a stroke, survivors often experience uncontrollable spasms that can twist their arms and hands into perpetual fists. The only treatments are expensive, frequently painful injections of botulinum toxin or oral medications so strong they may put patients to sleep. Both offer only temporary relief.Engineers at Stanford University and the Georgia Institute of Technology now say they have developed a glove-like wearable medical device that achieves as-good-or-better results as the injections or drugs by applying simple, high-frequency mechanical vibrations to the hands and fingers.“Vibration therapies are not unknown, so we knew we would see some effect, but clinically it was just amazing to see that these beneficial effects persist,” explained <a href="https://profiles.stanford.edu/allison-okamura" data-extlink="" target="_blank">Allison Okamura</a>, Richard W. Weiland Professor are the Stanford School of Engineering and senior author of a series of studies introducing the glove.“There are significant improvements in symptoms using the simulation method. And we think it can potentially address several effects of stroke — numbness, spasticity, and, for some, limited range of motion,” said <a href="https://neuroscience.stanford.edu/people/caitlyn-seim" data-extlink="" target="_blank">Caitlyn Seim</a>, a post-doctoral researcher in Okamura’s lab and initiator of the project. “We're most excited about treating spasticity because it affects so many people's quality of life and has such limited treatment options.”<h2>Form factor</h2>To the researchers’ knowledge this is the first effort to explore vibrotactile stimulation (VTS) technique at a wearable scale. State-of-the-art methods employ whole-body vibration using machines that are large, expensive, and require visits to the clinic for treatment.Patients in trials wore the VTS device three hours a day for eight weeks. Results were compared to the effectiveness of injections and oral medications. When measured, more than half of participants who receive regular botulinum injections had equal or better results with daily use of the VTS glove.“I think we can safely say that VTS is at least as good as injections and oral medicines,” Okamura said. “And it was exciting to see there is some maintenance of the improvements over time, though more study of that is needed.”The prototype device was first developed by Seim and colleagues at Georgia Tech as a tool to help people learn motor tasks such as typing or playing musical instruments via haptic guidance. The device was later studied as an interactive music exercise tool for people with partial spinal cord injuries, which led the team to the realization that haptic stimulation may be therapeutic on its own. Their unique wearable form factor makes a new paradigm in intensive stimulation therapy possible, since users can wear the gloves throughout the day.“We started to wonder if stimulation might also be a therapeutic tool for brain and spinal injury. It was very exciting,” Seim said.<img src="https://s3-us-west-1.amazonaws.com/wevolver-project-images/froala%2F1707898661498-vibrating-glove-helps-1.jpg" style="width: 766px;" class="fr-fic fr-dib">The VTS Glove on a patient’s hand. The team engineered and fabricated over 20 devices for this study in-house in Stanford labs. | Image courtesy of Andrew Brodhead<h2 id="isPasted">Notable results</h2>The latest version of the VTS device wraps around the wrist, palm, and fingers and includes motors that provide continual high-frequency stimulation to individual fingers as well as muscles in the hand and wrist. The vibrations are subtle and unobtrusive — similar to the intensity of a cell phone vibrating. Patients are free to go about their normal activities while wearing the device.Neurologically, the mechanisms underlying the symptom improvements are still being studied, but the team theorizes that the device is taking advantage of the brain’s remarkable plasticity — its ability to find new pathways in response to damage or dysfunction. They believe that the VTS vibrations can modulate out-of-control muscles and send neural signals from the muscles back to the brain where the signals re-train undamaged areas of the brain. &nbsp; &nbsp; &nbsp; &nbsp; &nbsp; .“The brain is essentially relearning the ability to perceive touch and proprioception,” Seim said of the brain’s ability to feel and understand where and how the arm, hands, and fingers are positioned in three-dimensional space.In candid video testimonials, patients speak in glowing terms of their preference for VTS over injections and medication. Those same patients also say that the VTS glove is “pleasant” or at least “comfortable” to wear. VTS is non-invasive, inexpensive, and avoids the side effects of injections and muscle relaxants. Most promising of all, Seim notes that many patients in the trials reported they voluntarily reduced their use of oral medications and some even planned to forego quarterly botulinum injections in favor of the VTS glove &nbsp; &nbsp; .“This is the magic glove, it’s better than [botulinum],” said one patient after just two weeks using VTS. “My fingers and wrist are more relaxed. Before it was very difficult to straighten my fingers and now it’s a lot easier.”“I stopped my morning dose of [muscle relaxer] and now I want to stop taking my night dose because the glove is working and I don’t need it,” noted another patient after a similar two-week period.The hope may be shared as both researchers say they believe VTS might also prove effective in other brain injury-related motor conditions and diseases — areas the team is already pursuing as they explore stroke effectiveness.“There are currently 100 million people worldwide living with stroke,” Seim said. “As many as one third experience these paralyzing arm spasms. We targeted the largest-possible population first, but certainly other conditions are on our radar.”As of now, the VTS device is available only to patients in the clinical trial, and Okamura and Seim are gearing up for the next phases that will include additional clinical studies to understand the device’s long-term effectiveness and optimal design.To that end, the team recently received a considerable grant from the National Science Foundation’s Convergence Accelerator program to further develop the vibrotactile glove as a commercial product.“We think we have enough clinical study under our belt to know that VTS is a very safe, effective treatment,” Okamura said. “We'd love to start getting it out there as a publicly available therapy.”Okamura is also a member of&nbsp;<a href="http://biox.stanford.edu/" data-extlink="" target="_blank">Stanford Bio-X</a>, the&nbsp;<a href="https://humanperformance.stanford.edu/" data-extlink="" target="_blank">Wu Tsai Human Performance Alliance</a>, and the&nbsp;<a href="https://neuroinstitute.stanford.edu/" data-extlink="" target="_blank">Wu Tsai Neurosciences Institute</a>, and a faculty affiliate of the&nbsp;<a href="https://hai.stanford.edu/" data-extlink="" target="_blank">Institute for Human-Centered Artificial Intelligence (HAI)</a>.

Postdoctoral researcher Caitlyn Seim takes measurements with a participant in the clinical trial. | Image courtesy of Andrew Brodhead

For those with stroke, involuntary contractions of the hands and arms often follow. A simple, wearable vibrating glove may offer a more effective treatment.

Vibrating glove helps stroke patients recover from muscle spasms

This article was discussed in our <a href="https://www.wevolver.com/profile/the.next.byte" rel="noopener noreferrer" target="_blank">Next Byte podcast</a>.&nbsp;<iframe height="200px" width="100%" frameborder="no" scrolling="no" seamless="" src="https://player.simplecast.com/1e9bb08c-384a-4d12-983e-8af2e63c741b?dark=false" class="fr-draggable" data-lf-form-tracking-inspected-kn9eq4roawkarlvp="true" data-lf-yt-playback-inspected-kn9eq4roawkarlvp="true" data-lf-vimeo-playback-inspected-kn9eq4roawkarlvp="true"></iframe> The full article will continue below.<hr>MIT engineers have developed a small ultrasound sticker that can monitor the stiffness of organs deep inside the body. The sticker, about the size of a postage stamp, can be worn on the skin and is designed to pick up on signs of disease, such as liver and kidney failure and the progression of solid tumors.<img src="https://images.wevolver.com/eyJidWNrZXQiOiJ3ZXZvbHZlci1wcm9qZWN0LWltYWdlcyIsImtleSI6ImZyb2FsYS8xNzA3NzI0MzU5MjkzLU1JVC1TZWVpbmdTdGlmZm5lc3MtMDEtcHJlc3NfMC5qcGciLCJlZGl0cyI6eyJyZXNpemUiOnsid2lkdGgiOjk1MCwiZml0IjoiY292ZXIifX19" style="width: 766px;" class="fr-fic fr-dib">A small ultrasound sticker, worn on the skin, can monitor the stiffness of organs deep inside the body. The MIT-developed sensor could detect signs of disease such as liver and kidney failure, and the progression of solid tumors. Image: Courtesy of the researchersIn an <a href="https://science.org/doi/10.1126/sciadv.adk8426" target="_blank">open-access study appearing today</a> in Science Advances, the team reports that the sensor can send sound waves through the skin and into the body, where the waves reflect off internal organs and back out to the sticker. The pattern of the reflected waves can be read as a signature of organ rigidity, which the sticker can measure and track.“When some organs undergo disease, they can stiffen over time,” says the senior author of the paper, Xuanhe Zhao, professor of mechanical engineering at MIT. “With this wearable sticker, we can continuously monitor changes in rigidity over long periods of time, which is crucially important for early diagnosis of internal organ failure.”The team has demonstrated that the sticker can continuously monitor the stiffness of organs over 48 hours and detect subtle changes that could signal the progression of disease. In preliminary experiments, the researchers found that the sticky sensor can detect early signs of acute liver failure in rats.The engineers are working to adapt the design for use in humans. They envision that the sticker could be used in intensive care units (ICUs), where the low-profile sensors could continuously monitor patients who are recovering from organ transplants.“We imagine that, just after a liver or kidney transplant, we could adhere this sticker to a patient and observe how the rigidity of the organ changes over days,” lead author Hsiao-Chuan Liu says. “If there is any early diagnosis of acute liver failure, doctors can immediately take action instead of waiting until the condition becomes severe.” Liu was a visiting scientist at MIT at the time of the study and is currently an assistant professor at the University of Southern California.The study’s MIT co-authors include Xiaoyu Chen and Chonghe Wang, along with collaborators at USC.Sensing wobblesLike our muscles, the tissues and organs in our body stiffen as we age. With certain diseases, stiffening organs can become more pronounced, signaling a potentially precipitous health decline. Clinicians currently have ways to measure the stiffness of organs such as the kidneys and liver using ultrasound elastography — a technique similar to ultrasound imaging, in which a technician manipulates a handheld probe or wand over the skin. The probe sends sound waves through the body, which cause internal organs to vibrate slightly and send waves out in return. The probe senses an organ’s induced vibrations, and the pattern of the vibrations can be translated into how wobbly or stiff the organ must be.Ultrasound elastography is typically used in the ICU to monitor patients who have recently undergone an organ transplant. Technicians periodically check in on a patient shortly after surgery to quickly probe the new organ and look for signs of stiffening and potential acute failure or rejection.“After organ transplantation, the first 72 hours is most crucial in the ICU,” says another senior author, Qifa Zhou, a professor at USC. “With traditional ultrasound, you need to hold a probe to the body. But you can’t do this continuously over the long term. Doctors might miss a crucial moment and realize too late that the organ is failing.”The team realized that they might be able to provide a more continuous, wearable alternative. Their solution expands on an <a href="https://news.mit.edu/2022/ultrasound-stickers-0728" target="_blank">ultrasound sticker</a> they previously developed to image deep tissues and organs.“Our imaging sticker picked up on longitudinal waves, whereas this time we wanted to pick up shear waves, which will tell you the rigidity of the organ,” Zhao explains.Existing ultrasound elastrography probes measure shear waves, or an organ’s vibration in response to sonic impulses. The faster a shear wave travels in the organ, the stiffer the organ is interpreted to be. (Think of the bounce-back of a water balloon compared to a soccer ball.)The team looked to miniaturize ultrasound elastography to fit on a stamp-sized sticker. They also aimed to retain the same sensitivity of commercial hand-held probes, which typically incorporate about 128 piezoelectric transducers, each of which transforms an incoming electric field into outgoing sound waves.“We used advanced fabrication techniques to cut small transducers from high-quality piezoelectric materials that allowed us to design miniaturized ultrasound stickers,” Zhou says.The researchers precisely fabricated 128 miniature transducers that they incorporated onto a 25-millimeter-square chip. They lined the chip’s underside with an adhesive made from hydrogel — a sticky and stretchy material that is a mixture of water and polymer, which allows sound waves to travel into and out of the device almost without loss.In preliminary experiments, the team tested the stiffness-sensing sticker in rats. They found that the stickers were able to take continuous measurements of liver stiffness over 48 hours. From the sticker’s collected data, the researchers observed clear and early signs of acute liver failure, which they later confirmed with tissue samples.“Once liver goes into failure, the organ will increase in rigidity by multiple times,” Liu notes.“You can go from a healthy liver as wobbly as a soft-boiled egg, to a diseased liver that is more like a hard-boiled egg,” Zhao adds. “And this sticker can pick up on those differences deep inside the body and provide an alert when organ failure occurs.”The team is working with clinicians to adapt the sticker for use in patients recovering from organ transplants in the ICU. In that scenario, they don’t anticipate much change to the sticker’s current design, as it can be stuck to a patient’s skin, and any sound waves that it sends and receives can be delivered and collected by electronics that connect to the sticker, similar to electrodes and EKG machines in a doctor’s office.“The real beauty of this system is that since it is now wearable, it would allow low-weight, conformable, and sustained monitoring over time,” says Shrike Zhang,&nbsp;an associate professor of medicine at Harvard Medical School and associate bioengineer at Brigham and Women’s Hospital, who was not involved with the study. “This would likely not only allow patients to suffer less while achieving prolonged, almost real-time monitoring of their disease progression, but also free trained hospital personnel to other important tasks.”The researchers are also hoping to work the sticker into a more portable, self-enclosed version, where all its accompanying electronics and processing is miniaturized to fit into a slightly larger patch. Then, they envision that the sticker could be worn by patients at home, to continuously monitor conditions over longer periods, such as the progression of solid tumors, which are known to harden with severity.“We believe this is a life-saving technology platform,” Zhao says. “In the future, we think that people can adhere a few stickers to their body to measure many vital signals, and image and track the health of major organs in the body.”

“We used advanced fabrication techniques to cut small transducers from high-quality piezoelectric materials that allowed us to design miniaturized ultrasound stickers,” Xuanhe Zhao, professor of mechanical engineering at MIT, says. Image: Courtesy of the researchers

The sticky, wearable sensor could help identify early signs of acute liver failure.

This ultrasound sticker senses changing stiffness of deep internal organs

In this episode, we talk about a new AI designed catheter that is 100x safer than and how it came to be after a passive conversation about fun facts between two researchers.

Medical Devices

Profiles