Researchers at the University of Waterloo in Canada have developed plant-based microrobots that are intended to pave the way for medical robots that can enter the body and perform tasks, such as obtaining a biopsy or performing a surgical procedure. The robots consist of a hydrogel material that is biocompatible and the composite contains cellulose nanoparticles derived from plants. The researchers can tune the orientation of the cellulose nanoparticles such that they respond in predictable ways when exposed to certain chemical cues such as changes in pH. This includes changing the shape of the tiny robots so that they are better adapted to their immediate environment. Incorporating magnetic elements allows the robots to be moved using external magnetic fields and deliver cargoes, such as drugs, to different areas of the body.

Researchers are working hard to expand the role of larger soft robots in the field of medicine. These devices are particularly good at interacting with soft tissues because of their mechanical properties, and therefore have enormous potential as surgical robots or those that provide assistance for daily living. However, soft microrobotics is a relatively underexplored area, but tiny soft structures that can travel throughout the body without causing significant damage to soft tissues intuitively seems like a winning idea.

This latest advancement comes in the form of a plant-based soft material made using cellulose nanoparticles that is non-toxic and biocompatible. The soft material also has self-healing properties, meaning that it can be cut and stuck back together without any adhesive, potentially allowing clinicians to easily customize it for different applications depending on the required size and shape.

The robots are a maximum of one centimeter in length and can be moved by incorporating magnetic components that can then be influenced using magnetic fields applied outside the body. In this manner, the robots can deliver drugs or other therapeutics to precise areas of the body.  “In my research group, we are bridging the old and new,” said Hamed Shahsavan, a researcher involved in the project. “We introduce emerging microrobots by leveraging traditional soft matter like hydrogels, liquid crystals, and colloids.”

In tests so far, the researchers have been able to manipulate the robots to travel through a maze, suggesting that they may be able to navigate our tortuous vasculature.

See a Waterloo Engineering video of this process below:

Study in Nature Communications: Programmable nanocomposites of cellulose nanocrystals and zwitterionic hydrogels for soft robotics

Flashback: Soft Robot Grows Like a Plant to Travel Through Tight Spaces

Via: University of Waterloo

A research team at the University of California San Diego have developed a smartphone attachment that can provide information on changes in pupil size, which can be used to assess neurological phenomena, such as traumatic brain injury and Alzheimer’s disease. Such changes in pupil size have been difficult to characterize in the past in those with a dark iris, which is more common in people with darker skin tones, because it can be challenging to distinguish between the iris and the pupil. This latest smartphone attachment fits over the camera of a smartphone, and uses a filter to restrict the light entering the camera to far-red light. This makes the iris appear lighter in the resulting images, and helps the technology to distinguish between iris and pupil, providing more robust diagnostics for those with dark eyes.

Changes in pupil size can offer information on a variety of neurological conditions, including traumatic brain injury and Alzheimer’s disease, but our natural diversity in terms of skin tone and melanin content in the iris has meant that for those with dark eyes, it can be difficult to get an accurate measurement in pupil size changes.

“There has been a large issue with medical device design that depends on optical measurements ultimately working only for those with light skin and eye colors, while failing to perform well for those with dark skin and eyes,” said Edward Wang, one of the leaders of this research. “By focusing on how we can make this work for all people while keeping the solution simple and low cost, we aim to pave the way to a future of fair access to remote, affordable healthcare.”

Engineers within ophthalmology have known that conventional cameras are not suitable for pupil size measurements in those with dark eyes for some time. One answer has been to use infrared cameras, but such cameras are typically only present on high-end smartphones, which limits the pool of people who could use such technology. This latest device works with a conventional smartphone camera, and instead uses far-red light, which is still within the visible spectrum and therefore detectable with a regular camera.  

“The issue with relying on specialized sensors like an infrared camera is that not all phones have it,” said Colin Barry, another researcher involved in the project. “We created an inexpensive and fair solution to provide these kinds of emerging neurological screenings regardless of the smartphone price, make or model.”

The attachment is placed over the camera and then placed over the eye, where the camera flashes the eye with bright light and records video of the pupil movement. In tests so far, the device could assess pupil responses in a group of volunteers with different eye colors.  

Study in Scientific Reports: Racially fair pupillometry measurements for RGB smartphone cameras using the far red spectrum

Via: University of California San Diego

Engineers at the University of British Columbia have collaborated with the Japanese automotive company Honda to develop an e-skin for robotic prostheses that allows such devices to sense their environment in significant detail. The soft skin is highly sensitive, letting robotic hands to perform tasks that require a significant degree of dexterity and tactile feedback, such as grasping an egg or lifting a glass of water without breaking it. The elastomer skin contains fixed and sliding pillars that allow it to buckle and wrinkle, like real skin. The skin contains four deformable capacitators that let it distinguish between normal and shear forces, meaning that it can finely control its interaction with grasped objects. The researchers hope that the technology will enhance robotic prostheses and allow users to expand the range of daily activities they can perform using their prosthetic devices.

Robotic prostheses are evolving, and sensors are required to evolve in tandem. Grasping delicate objects with a robotic hand could spell disaster without a sensor that can measure how much force is being applied and determine the correct amount of force to apply. After all, our own skin is highly attuned to the subtleties of the objects we touch. Skin-like sensors continue to progress, with a variety of technologies emerging in recent years that can permit robots and robotic prostheses to sense their environment more comprehensively.

This latest e-skin is highly sensitive, expanding the types of activities that are possible. “Our sensor can sense several types of forces, allowing a prosthetic or robotic arm to respond to tactile stimuli with dexterity and precision,” said Mirza Saquib Sarwar, a researcher involved in the study. “For instance, the arm can hold fragile objects like an egg or a glass of water without crushing or dropping them.”

The technology may also be useful for medical or assistive robots, such as those that care for the elderly, or even surgical robots that interact with soft tissues inside the body. “Our sensor uses weak electric fields to sense objects, even at a distance, much as touchscreens do,” said John Madden, another researcher involved in the study. “But unlike touchscreens, this sensor is supple and can detect forces into and along its surface. This unique combination is key to adoption of the technology for robots that are in contact with people.”

The skin is easy to fabricate at scale, and can be made in large sheets that can cover significant areas. However, the researchers are keen to stress that this technology will evolve much further in the future. “Human skin has a hundred times more sensing points on a fingertip than our technology does, making it easier to light a match or sew,” said Madden. “As sensors continue to evolve to be more skin-like, and can also detect temperature and even damage, there is a need for robots to be smarter about which sensors to pay attention to and how to respond. Developments in sensors and artificial intelligence will need to go hand in hand.”

Study in journal Scientific Reports: Touch, press and stroke: a soft capacitive sensor skin

Via: University of British Columbia

Researchers at the National University of Singapore have developed a magneto-responsive hydrogel wound dressing that also contains two different regenerative cell types. The hydrogel is also embedded with magnetic particles that can be stimulated using an external magnetic field. The action of the magnetic field on the gel-encapsulated particles causes mechanical stresses within the gel to act on the cells, stimulating them to grow and enhancing their regenerative potential. The advanced dressing is intended to assist in healing diabetic wounds, which can be difficult to treat.

In diabetes, various issues can impair wound healing, leading to chronic wounds that are so difficult to treat that it is not uncommon for them to result in an amputation. Wound management and facilitating wound healing is particularly challenging in such patients. Part of the problem lies in the dressings that are used to cover such wounds.  

“Conventional dressings do not play an active role in healing wounds,” said Andy Tay, one of the lead researchers that developed the new dressing. “They merely prevent the wound from worsening and patients need to be scheduled for dressing change every two or three days. It is a huge cost to our healthcare system and an inconvenience to patients.”

To address this, these researchers have created an advanced diabetic wound dressing that aims to actively encourage wound healing. The hydrogel dressing contains keratinocytes, a cell type involved in skin repair and fibroblasts, which are a key component of connective tissue. Under normal circumstances, skin cells experience mechanical deformation as our skin moves, which stimulates them. However, patients with a wound may have lower mobility, which limits the ability of the cells within the wound to heal it.

These researchers have introduced the same mechanical deformation process into their hydrogel dressing. It contains a multitude of tiny magnetic particles. When the dressing is exposed to a magnetic field, the particles act to create mechanical stress on the cells. “What our team has achieved is to identify a sweet spot by applying gentle mechanical stimulation,” said Tay. “The result is that the remaining skin cells get to ‘work-out’ to heal wounds, but not to the extent that it kills them.”

In tests so far, this magnetic/mechanical stimulation increased cell growth rates by 240% and doubled the amount of collagen that the cells produced. “The approach we are taking not only accelerates wound healing but also promotes overall wound health and reduces the chances of recurrence,” said Tay.

A bandage pre-loaded with magnetic hydrogel is placed on the wound, and an external device is used to accelerate the wound healing process.

Study in journal Advanced Materials: Mechano‐Activated Cell Therapy for Accelerated Diabetic Wound Healing

Via: National University of Singapore

A team at the University of Technology Sydney has developed an assistive technology for blind people and those with low vision. The system consists of glasses that can view their surroundings through an on-board camera, appraise the objects nearby using computer vision technology, and then play a sound that provides a cue for the wearer as to their surroundings. These “sound icons” could include a rustling sound when leaves are viewed, or a small bark when a dog appears, as examples. The technology could offer additional information on their environment for low vision wearers, and assist with daily tasks.

Technology that can reveal the world to those who are blind or have low vision is developing apace. Such systems have enormous potential in empowering such people to perform daily tasks, and render them less reliant on others for assistance, enhance their independence and confidence.

This latest technology is somewhat akin to the echolocation used by bats, although it relies on computer vision rather than soundwaves to identify nearby objects. However, sound is still used to communicate the identity of the viewed object in the form of sound icons.

“Smart glasses typically use computer vision and other sensory information to translate the wearer’s surrounding into computer-synthesized speech,” said Chin-Teng Lin, one of the creators of the new system. “However, acoustic touch technology sonifies objects, creating unique sound representations as they enter the device’s field of view. For example, the sound of rustling leaves might signify a plant, or a buzzing sound might represent a mobile phone,”  

So far, the researchers have tested the glasses with 14 participants. Of this group, half of the participants were blind or low sighted and the other half were fully sighted but wore a blindfold for the duration of the tests. The glasses allowed the wearers to successfully identify and grasp objects that were present within the field of view of the system.

“The auditory feedback empowers users to identify and reach for objects with remarkable accuracy,” said Howe Zhu, another researcher involved in the study. “Our findings indicate that acoustic touch has the potential to offer a wearable and effective method of sensory augmentation for the visually impaired community.”

Study in journal PLOS ONE: An investigation into the effectiveness of using acoustic touch to assist people who are blind

Via: University of Technology Sydney

Researchers at North Carolina State University have developed a robotic prosthetic ankle that can provide stability for lower limb amputees. The ankle uses electromyographic sensors placed on the sites of muscles in the residual limb that then convey the intentions of the wearer with regard to movement. So far, the system has been shown to assist with postural control, which in this context refers to the many complex and unconscious movements that the muscles in our legs make to maintain balance and keep us upright, even when we are largely standing still. Previously, lower limb amputees have sometimes struggled to maintain postural control, even with robotic prostheses.      

Sometimes, even standing in one place requires some effort, particularly for those with a lower limb amputation. You may be unaware of the activity of your muscles in constantly maintaining balance and posture, even while standing still. This has been hard to recreate in robotic prostheses, but this latest technology aims to assist through a robotic ankle that can monitor muscle activity in the residual limb and make adjustments accordingly to assist in maintaining balance.

“This work focused on ‘postural control,’ which is surprisingly complicated,” said Helen Huang, one of the developers of the new technology. “Basically, when we are standing still, our bodies are constantly making adjustments in order to keep us stable. For example, if someone bumps into us when we are standing in line, our legs make a wide range of movements that we are not even necessarily aware of in order to keep us upright. We work with people who have lower limb amputations, and they tell us that achieving this sort of stability with prosthetic devices is a significant challenge. And this study demonstrates that robotic prosthetic ankles which are controlled using electromyographic (EMG) signals are exceptionally good at allowing users to achieve this natural stability.”  

The researchers tested their robotic device with five volunteers who had previously undergone a below-knee amputation on one leg. “Basically, the sensors are placed over the muscles at the site of the amputation,” said Aaron Fleming, another researcher involved in the study. “When a study participant thinks about moving the amputated limb, this sends electrical signals through the residual muscle in the lower limb. The sensors pick these signals up through the skin and translate those signals into commands for the prosthetic device.”

The volunteers were then subjected to a pre-agreed perturbation that could throw off their balance, to see how the robotic ankle helped them to maintain their balance. “Specifically, the robotic prototype allowed study participants to change their postural control strategy,” said Huang. “For people who have their intact lower limb, postural stability starts at the ankle. For people who have lost their lower limb, they normally have to compensate for lacking control of the ankle. We found that using the robotic ankle that responds to EMG signals allows users to return to their instinctive response for maintaining stability.”

Study in journal Science Robotics: Neural prosthesis control restores near-normative neuromechanics in standing postural control

Via: North Carolina State University

Charco Neurotech, a medtech company based in the United Kingdom, has developed CUE1, a non-invasive wearable that is intended to assist those with Parkinson’s disease to manage their motor symptoms. The device is typically affixed to the sternum, and provides vibratory action in a focused region of the body. The technology is based on the observation of a doctor in the early 1800s, who noticed that their patients’ motor symptoms were significantly reduced when they traveled to their appointments over bumpy roads in a horse and carriage.

The technology also uses cueing to assist patients who might be prone to ‘freezing’ to increase their mobility. As a drug-free, non-invasive treatment option, the technology has plenty of attractive features for patients who might be willing to try it, and it is currently available in the UK, with plans for expansion soon.     

See a video below about the CUE1 and how it works:

Medgadget had the opportunity to speak with Lucy Jung, Co-founder and CEO at Charco Neurotech, about the technology.  

Conn Hastings, Medgadget: Please give us a basic overview of Parkinson’s disease.

Lucy Jung, Charco Neurotech: Parkinson’s is one of the world’s fastest-growing neurological disorders, with more than 10 million people living with it worldwide. The symptoms of Parkinson’s, such as shaking, stiffness, and lack of balance and coordination, can be attributed to a loss of neurotransmitters in the brain, most notably dopamine.

The aforementioned symptoms are just a few examples – there are over 40 symptoms of Parkinson’s. These symptoms can have a large impact on the day-to-day quality of life of people with Parkinson’s.

Medgadget: How do patients manage their symptoms at present? How is this suboptimal?

Jung: The current symptom management for Parkinson’s includes a variety of physical exercises, medication and surgery such as deep brain stimulation. As symptoms become more severe for those with Parkinson’s, they are unable to freely move, meaning their level of physical movement decreases. With visits to clinicians every 6 to 12 months, it can be difficult to tell how one’s daily symptoms change, and as such, how to adjust medication regimes.

Medgadget: What inspired Charco Neurotech to develop technologies to treat Parkinson’s? How did the idea for the CUE1 come about?

Jung: I have been researching long-term health disorders for over a decade now. In 2013, I met with a gentleman with Parkinson’s who was really happy to see our team but could not smile as Parkinson’s had taken away his smile. This led my co-founder and I to our mission to bring smiles back to people with Parkinson’s through Charco.

The inspiration behind the CUE1 came about by talking to people with Parkinson’s about how various stimulations can help day-to-day, and by delving deeper into the characteristics of these stimulations. From there, it was a continuous process of prototyping and iterating with people with Parkinson’s at the forefront. Their feedback has always been central to our development of the CUE1.

Medgadget: When and how was focused stimulation discovered as reducing Parkinson’s symptoms? How does cueing work in assisting Parkinson’s patients?

Jung: In the early 19th century, Dr. Jean-Martin Charcot first noticed that vibration could help reduce symptoms for people with Parkinson’s as he found those who visited him by railroad or carriage had reduced symptom severity in comparison to those whom he visited. Recent studies have shown that localized stimulation, instead of full-body vibration, can be more effective in alleviating symptoms.

Cueing works by providing a person with an external trigger (a cue) for movement. It is most effective for those who commonly experience freezing episodes, where they may be unable to move for several seconds or minutes at a time. The cues can then help someone time and trigger their movement.

Medgadget: Please give us an overview of the CUE1, its feature,s and how it is used.

Jung: The CUE1 is a non-invasive, wearable, medical device which utilizes focused vibrotactile stimulation in conjunction with cueing to alleviate movement-based symptoms for people with Parkinson’s. Aside from that, the device can also provide medication reminders and symptom tracking through the use of the CUE mobile application.

Medgadget: How does the CUE1 use focused stimulation and cueing to treat Parkinson’s symptoms?

Jung: Worn commonly on the sternum, the CUE1 provides localized pulsed vibration to the user. The focused stimulation can help reduce the high beta frequency band activity in the brain, leading to the body being in a more ready-to-move state and reducing stiffness and slowness. The cueing provides those triggers for movement, which help with smoother and freer movement. In combination, the two therapies help alleviate the movement-based symptoms, leading to an improved day-to-day quality of life.

Medgadget: What stage of development is the device at currently? When do you anticipate that it could be available?

Jung: The device is already available in the UK with more than 2,500 people using it, and we are in the process of scaling up our production. We are also working on the initial, limited EU and US expansion of the CUE1 and are very excited about bringing more smiles back to people with Parkinson’s.

Link: Charco Neurotech homepage…

A team at Columbia University School of Engineering and Applied Science has developed a technique to enhance chimeric antigen receptor (CAR) T cell therapy in solid tumors. The technique involves engineering E. coli bacteria, that naturally tend to accumulate in the immune privileged core of solid tumors. The bacteria have been engineered to interact with tumor cells and deposit a synthetic antigen on the cells that can then be targeted by CAR T cells. The approach could enhance CAR T cell therapy in solid tumors, which hasn’t worked as well as CAR T cell therapy for blood-borne cancers to date. Creating such bacterial/T cell tag teams could expand the variety of cancers that can be treated using T cell therapy and also enhance the tumor cell killing effects of T cells.   

CAR T cells are white blood cells that have been primed to attack cancer cells. While this approach has worked reasonably well in blood-borne cancers, such as leukemia, it has proven more difficult to target solid tumors. Such solid tumors are dense, have an erratic blood supply, and the cells within the tumor contain many biochemical signals that are also found in healthy tissue, making it difficult to distinguish and target cancers. Using CAR T cells to targeting tumor antigens that naturally occur in such solid tumors does not typically appear to provide sufficient cell killing activity.

These issues prompted these Columbia researchers to design a little helper for CAR T cells that can paint the tumor cells with an irresistible synthetic antigen that the CAR T cells are highly disposed to target. “Our probiotic platform enables CAR-T cells to attack a broad range of tumor types,” said Tal Danino, a researcher involved in the study. “Traditional CAR-T therapies have relied on targeting natural tumor antigens. This is the first example of pairing engineered T cells with engineered bacteria to deliver synthetic antigens safely, systemically, and effectively to solid tumors. This could have a significant impact on the treatment of many cancers.”

Given that the bacteria naturally tend to accumulate at a tumor core, the system may represent a universal CAR-T technology, that can be used for any solid tumor, without the need to customize the system for each tumor type or patient. This could dramatically expand the types of tumors that can be treated in this way.

“Combining the advantages of tumor-homing bacteria and CAR-T cells provides a new strategy for tumor recognition, and this builds the foundation for engineered communities of living therapies,” said Rosa Vincent, another researcher involved in the study. “We chose to bridge the individual limitations of these two cell therapies by combining the best features of each — using bacteria to place the targets, and T cells to destroy the malignant cells.”

Study in journal Science: Probiotic-guided CAR-T cells for solid tumor targeting

Via: Columbia University

Researchers at Rice University have developed a magnetoelectric material that converts a magnetic field into an electric field. The material can be formulated such that it can be injected into the body, near a neuron, and then an alternating magnetic field can be applied to the area from outside the body. Magnetic fields are very useful in this context, as they can easily penetrate tissue without causing any damage. This magnetoelectric effect produces a small electrical current near the neuron, effectively stimulating it, without the need for invasive implants. So far, the researchers have shown that the technology can bridge a completely severed sciatic nerve in rats, suggesting that it has potential as a component in neuroprosthetics.  

Neural stimulation can have all sorts of interesting and exciting therapeutic effects, but implanting neural stimulators is invasive, and they can require later removal because of device failure or simply to change a battery. A substance that is present in dimensions small enough to pass through a hypodermic needle, but then provide a similar neurostimulatory effect under the influence of a minimally invasive device that is positioned outside the body has some obvious advantages over a conventional implant.

“We asked, ‘Can we create a material that can be like dust or is so small that by placing just a sprinkle of it inside the body you’d be able to stimulate the brain or nervous system?’” said Joshua Chen, a researcher involved in the study. “With that question in mind, we thought that magnetoelectric materials were ideal candidates for use in neurostimulation. They respond to magnetic fields, which easily penetrate into the body, and convert them into electric fields — a language our nervous system already uses to relay information.”

The material consists of the following: a piezoelectric layer of lead zirconium titanate between two magnetorestrictive layers of metallic glass alloys, onto which platinum, hafnium oxide, and zinc oxide were layered. The magnetorestrictive components in the material vibrate when an alternating magnetic field is applied. “This vibration means it basically changes its shape,” said Gauri Bhave, another researcher involved in the study. “The piezoelectric material is something that, when it changes its shape, creates electricity. So, when those two are combined, the conversion that you’re getting is that the magnetic field you’re applying from the outside of the body turns into an electric field.”

So far, the researchers have shown that the technology can restore function to a completely severed sciatic nerve in rats. “We can use this metamaterial to bridge the gap in a broken nerve and restore fast electric signal speeds,” said Chen. “Overall, we were able to rationally design a new metamaterial that overcomes many challenges in neurotechnology. And more importantly, this framework for advanced material design can be applied toward other applications like sensing and memory in electronics.”

Study in journal Nature Materials: Self-rectifying magnetoelectric metamaterials for remote neural stimulation and motor function restoration

Via: Rice University

Researchers at the Wyss Institute at Harvard University have developed a microfluidic chip that can recreate some of the features of radiation-induced lung injury. The lungs are very sensitive to radiation, and this can limit the application of radiotherapy to treat cancer. Accurately modeling radiation-induced lung injury could assist in developing new methods to prevent and treat the phenomenon, but it has been difficult to study this before the advent of advanced organ-on-a-chip models. The lung chip presented here contains human lung alveolar epithelial cells interfacing with lung capillary cells. The goal is to recreate the alveolar-capillary interface, and then by exposing the chip to radiation, the researchers can monitor the effects on these cellular populations in detail, as well as trying new treatments to reduce the effects of radiation.

The lungs are highly sensitive to radiation, with significant exposure resulting in radiation-induced lung injury. This manifests as sustained inflammation and fibrosis, which can affect lung function. This can be an issue for survivors of nuclear accidents, who may have inhaled contaminated particles, but it can also affect patients undergoing radiotherapy whereby dose limitation is required to avoid significant damage to the lungs. In any case, discovering how and why the lungs are so sensitive to radiation, and trialing new treatments offers hope for such patients.

The issue is that is has been difficult to study this phenomenon to date. Radiation-induced lung injury is a complex condition, and can vary significantly between patients based on a variety of risk factors. Moreover, animal models of the condition do not typically recapitulate its complex presentation and entail serious ethical concerns. In response, these researchers have developed an advanced in vitro system that can mimic some of the aspects of radiation-induced lung damage.

The chip is a microfluidic culture system that contains human lung alveolar epithelial cells in one channel, where they are exposed to air as in the lung, and another channel containing lung capillary endothelial cells that are exposed to a nutrient medium as a blood surrogate. This medium also contains immune cells, as they are relevant in radiation-induced injury. The two channels are separated by a semi-permeable membrane. The chip can be exposed to clinically relevant doses of radiation, and then the cellular responses can be measured.

The team quantified the appearance of so-called “DNA damage foci” created by the repair protein p53. Each visualized spackle represents one such foci, and the number of spackles in both, epithelial (top row) and endothelial cells (bottom row) increases with the radiation dose they applied to the alveolar-capillary interface on the chips. Credit: Wyss Institute at Harvard University

“Forming a better understanding of how radiation injury occurs and finding new strategies to treat and prevent it poses a multifaceted challenge that in the face of nuclear threats and the realities of current cancer therapies needs entirely new solutions,” said Donald Ingber, Wyss Institute Director. “The Lung Chip model that we developed to recapitulate development of radiation-induced lung damage injury leverages our extensive microfluidic Organ Chip culture expertise and, in combination with new analytical and computational drug and biomarker discovery tools, gives us powerful new inroads into this problem.”

Study in journal Nature Communications: A human lung alveolus-on-a-chip model of acute radiation-induced lung injury

Via: Wyss Institute