Tag: medical technology

Upgrading the Diagnostic Power of Dipsticks

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Popularly known as ‘dipsticks’, lateral flow assays (LFAs) have long been a standard point-of-care testing system, and continue to grow in popularity, especially in developing countries.

These disposable, paper-based diagnostic devices are inexpensive, readily available, have a long shelf life, and they’re fast, typically delivering results in under 20 minutes. They’re also easy to use at home, most commonly for pregnancy tests but also now for COVID.

“These tests have been extremely popular for years, mainly because they are so simple to use. You don’t send anything to the lab or clinic because these tests don’t require any external equipment to operate. This is an advantage,” said engineering researcher Fatih Sarioglu at the Georgia Institute of Technology. “But there also is a disadvantage. There are limitations to what they can do.”

Sarioglu and his team are overcoming the limitations of LFAs with development of a flow control technology, turning these simple tests into complex biomedical assays.

Their research is outlined in two papers in Science Advances and ACS Sensors. One explains the development of their technology and the other applies the technology in a toolkit to diagnose SARS-CoV-2, as well as influenza.

LFAs make use of capillary liquid flow to detect analytes. Sarioglu explained that conventional LFAs are not practical for performing multi-step assays – capillary flow precludes them from coordinating a complex process involving the application of multiple reagents in a specific sequence with specific delays in between.

The researchers describe a technique to control capillary flow by imprinting roadblocks on a laminated paper with water insoluble ink. The blocked liquid flow is thus manipulated into a void formed at the interface of the ink-infused paper and the polymer tape laminate. By modifying the roadblocks, the researchers can essentially set the time it takes for a void to form – creating timers that hold capillary flow for a desired period.

“By strategically imprinting these timers, we can program the assays to coordinate different capillary flows,” said Sarioglu, professor in the School of Electrical and Computer Engineering. “That enables multiple liquids to be introduced, and multistep chemical reactions, with optimal incubation times – so, we can perform complex, automated assays that otherwise would normally have to be performed in laboratories. This takes us beyond the conventional LFA.”

For the user, the new dipstick test works the same way as the reliable standard – a sample is added at one end and the results present themselves minutes later in living color(s) at the other end. Sarioglu and his colleagues simply enhanced and expanded the process in between.

Basically, they drew patterns on paper – a dipstick – and created immunoassays that rival other diagnostic tests requiring labs and extra equipment, in the effective detection of pathogenic targets like Zika virus, HIV, hepatitis B virus, or malaria, among others.

The paper in ACS Sensors describes a PCR-based point-of-care toolkit based on the lab’s flow technology. The assay is programmed to run a sequence of chemical reactions to detect SARS-CoV-2 and/or influenza A and influenza B. A traditionally labour-intensive genetic assay can now be done on a disposable platform which will enable frequent, on-demand self-testing, filling a critical need to track and contain outbreaks.

The lab is studying the technology’s application for other assays targeting other pathogens, with plans to publish in the coming months. Sarioglu is optimistic about the work’s potential.

“We believe this flow technology research will have widespread impact,” he said. “This kind of dipstick test is so commonly used by the public for biomedical testing, and now it can be translated into other applications that we do not traditionally consider to be cut out for these simple tests.”

Source: Georgia Institute of Technology

New Mask Recycling Technology Could Cut Down on Waste

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Researchers have developed a way to quickly disinfect and electrostatically recharge used N95 respirators, restoring their effectiveness against COVID and other airborne diseases.

In their study published in Environment Science & Technology, the University of South Florida (USF) team showed their sterilisation technology could restore an N95 respirator’s original filtration efficiency of about 95 percent, even after 15 cycles of treatment. The technology fights coronavirus by using corona discharge, an electrical technique which simultaneously deactivating pathogens on a mask and restoring its electrostatic charges. It doesn’t require heat, or chemicals or contact, making it safe and convenient to use. It is safer than ultraviolet (UV) radiation and uses little electricity.

As well as restoring protection, the corona discharge treatment can reduce the impact of used masks on the environment. In a report by OceansAsia, a marine conservation organisation, 1.56 billion face masks polluted the oceans in 2020 and will likely take more than 450 years to fully decompose. The researchers say the technology will limit mask consumption to dozens each year instead of hundreds.

“It is a reduction of 90 percent for each user. If we assume that 10 percent of the population all over the world takes advantage of corona discharge mask reuse technology, there will be four- five billion fewer masks disposed to the environment,” said project lead Ying Zhong, assistant professor in the USF Department of Mechanical Engineering. “It will reduce at least 24 million tons of plastic pollution and reduce the amount of chemicals used for mask disinfection and avoid their environmental impact.”

“Despite the challenging conditions of the pandemic, this was the most thrilling project that I have ever worked on. We wish our research advances the understanding of how corona discharge disinfection can be turned into products on the market as soon as possible,” said co-project lead Libin Ye, assistant professor in the USF Department of Cell Biology, Molecular Biology and Microbiology.

The researchers are now working to develop this technology into products for hospitals and use by the general public, including handheld sterilisation devices.

Source: EurekAlert!

Is Heart Pump Development Dead in the Water?

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At an annual meeting of the Heart Failure Society of America (HFSA), heart failure specialists agreed that recalling the HeartWare heart pump was good but debated whether its departure leaves the field of mechanical circulatory support (MCS) dead in the water.

In June, Medtronic stopped sales of its HeartWare Ventricular Assist Device (HVAD), citing excess neurological events and mortality with the device. As a result, Abbott’s HeartMate 3 became the only FDA-approved, durable left ventricular assist device (LVAD) on the market.

“Competition breeds innovation. When competition is absent or minimal, there is little incentive for corporations to innovate,” said Jennifer Cowger, MD, MS, of Henry Ford Hospital in Detroit, during the annual scientific meeting.

“While I believe the removal of the HVAD from the market was the ethical thing to do, unless we as a field start embracing MCS technology and change our messaging to the general cardiology community, our field is going to be viewed as niche to referring cardiologists and we’re going to face irrelevance and we’re going to have bad times ahead,” she added.

However Nancy Sweitzer MD, PhD, of the University of Arizona in Tucson, disagreed, pointing out that there are plenty of advances on the horizon.

Nine companies worldwide are developing heart pumps for this $3-4 billion market, Dr Sweitzer noted. Several devices under investigation — implantable ones with no external component — will probably proceed to first-in-man trials in the next year, she said. “There’s a lot of money if you do this well,” she added

Internal competition alone may be enough to advance the field, Sweitzer argued, citing Thoratec’s HeartMate II superseding their old HeartMate XVE.

“They put their own device up against their own device. So I would argue that corporate competition isn’t necessary when the stakeholders realize that we need to get better at this. I think the companies in this space realize there’s a huge unmet need here if we develop a really good MCS that was truly portable, gave people excellent quality of life, and had lower complications,” she said.

Yet given the pace of LVAD research, “in the next decade, we have cause for concern in the MCS field,” Dr Cowger countered.

Both debaters suggested that MCS technology shouldn’t stop at HeartMate 3, even with its relatively impressive performance.

“Outcomes on HeartMate 3 are not the outcomes we really want for these patients. There are still innumerable complications. Hospitalization rates are extraordinarily high in these patients post-implant even if they’re successful implants. They bleed, they get infected, they get strokes. That still happens,” noted Dr Sweitzer.

Innovation issues aside, Dr Cowger pointed out that HeartMate 3 is also much larger than the HVAD, and the smaller device’s loss leaves a gap for patients. She said negative media views had not helped the recent “sense of apathy and loss of enthusiasm for MCS”.

“Physicians don’t want to use technology that will harm or be perceived to harm patients,” she said, noting that sentiment has shifted from “VADs are sexy, cool” to “we would not choose LVADs over [heart] transplant.”

Source: MedPage Today

Fraud Trial of Theranos Boss Begins

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On Wednesday, the trial of Elizabeth Holmes, founder of medical technology company Theranos, began. Prosecutors alleged she “lied and cheated” for money and fame.

Ms Holmes faces 12 fraud charges over her role at the failed company which was once worth $9bn, facing up to 20 years in prison if found guilty.

She is accused of deceiving patients and investors about the company’s testing technology, which was claimed to diagnose basic illnesses from a few drops of blood. Her defence team argues that she was naive and her company simply failed.

“Failure is not a crime. Trying your hardest and coming up short is not a crime,” said defence lawyer Lance Wade in his opening statement on Wednesday.

Former Theranos executive Ramesh “Sunny” Balwani faces the same charges next year. He was romantically involved with Ms Holmes.

Ms Holmes, who founded Theranos in 2003 aged 19, was dubbed the world’s youngest self-made female billionaire and hailed as the “next Steve Jobs”.

In 2015 and 2016, investigations by the Wall Street Journal revealed Theranos’ blood-testing devices did not work and the company was doing most of its testing on commercially available machines made by other manufacturers. She initially denied these reports.

Prosecutor Robert Leach alleges that, after running out of funds, Ms Holmes and Mr Balwani turned to fraud in 2009, lying about the tests and exaggerating the firm’s performance. Mr Leach said this included falsely claiming the tests were vetted by Pfizer and being used by the US military.

The case will probably take months and Ms Holmes will likely take the stand — a necessary gamble in the face of overwhelming evidence that the technology did not work.

Ms Holmes “dazzled” Walgreens into using the company’s services, and the company brought her fame.

“She had become, as she sought, one of the most celebrated CEOs in Silicon Valley and the world. But under the facade of Theranos’ success there were significant problems brewing.”

 The defence’s Mr Wade said Ms Holmes “naively underestimated” the business challenges but did not attempt to defraud investors. Ms Holmes has also alleged years of emotional and psychological abuse by Mr Balwani, who has denied the allegations. She is likely to testify as to how this affected her.

Source: BBC News

New Prosthetic Arm Restores Normal Movements

A prosthetic arm being fitted. Source: This is Engineering on Unsplash

Researchers have developed a bionic arm for patients with upper-limb amputations that allows wearers to think, behave and function like a person without an amputation.

The arm combines three important functions – intuitive motor control, touch and grip kinaesthesia, the intuitive feeling of opening and closing the hand. The developers, led by Clevelend Clinic, published their findings in Science Robotics.

“We modified a standard-of-care prosthetic with this complex bionic system which enables wearers to move their prosthetic arm more intuitively and feel sensations of touch and movement at the same time,” said lead researcher Paul Marasco, PhD, associate professor  in Cleveland Clinic Lerner Research Institute’s Department of Biomedical Engineering. “These findings are an important step towards providing people with amputation with complete restoration of natural arm function.”

The system is the first to test all three sensory and motor functions in a neural-machine interface simultaneously in a prosthetic arm. The neural machine interface sends impulses from the brain to the arm and sensory information back to the brain.

“Perhaps what we were most excited to learn was that they made judgments, decisions and calculated and corrected for their mistakes like a person without an amputation,” said Dr Marasco. “With the new bionic limb, people behaved like they had a natural hand. Normally, these brain behaviors are very different between people with and without upper limb prosthetics.
The researchers tested their new bionic limb on two study participants with upper limb amputations who had previously undergone targeted sensory and motor reinnervation -procedures that establish a neural-machine interface by redirecting amputated nerves to remaining skin and muscles. 

In targeted sensory reinnervation, touching the skin with small robots activates sensory receptors that enable patients to perceive the sensation of touch. In targeted motor reinnervation, when patients think about moving their limbs, the reinnervated muscles communicate with a computerised prosthesis to move in the same way. Additionally, small, powerful robots vibrate kinesthetic sensory receptors in those same muscles which helps prosthesis wearers feel that their hand and arm are moving. The new prosthetic arm feels grip movement sensation, touch on the fingertips, and is controlled intuitively by thinking. Cameras lets the computer see the prosthetic’s position.

While wearing the advanced prosthetic, participants performed tasks reflective of basic, everyday behaviours that require hand and arm functionality, which were compared to people with traditional prosthetics and people without amputations.

According to Dr Marasco, because the limb lacks sensation, people with traditional prosthetics behave differently than people without an amputation when performing tasks. For example, traditional prosthesis wearers must constantly watch their prosthetic while using it, and have difficulty correcting for the correct amount of force needed.

The researchers could see that the study participants’ brain and behavioural strategies changed to match those of a person without an amputation. They no longer needed to watch their prosthesis, they could locate things without looking, and they could more effectively correct mistakes.

“Over the last decade or two, advancements in prosthetics have helped wearers to achieve better functionality and manage daily living on their own,” said Dr. Marasco. “For the first time, people with upper limb amputations are now able to again ‘think’ like an able-bodied person, which stands to offer prosthesis wearers new levels of seamless reintegration back into daily life.”

Source: Cleveland Clinic

A Leak-proof, Biocompatible Intestinal Patch

Researchers at Empa have developed a patch that stably seals two sutured pieces of intestine and thus prevents dangerous leaks.

A burst appendix or a life-threatening intestinal volvulus are emergencies that need to be treated by surgeons immediately. However, operations carry risks: highly acidic digestive juices and intestinal bacteria can leak out, causing peritonitis and sepsis.

Sealing sutured tissue with a plaster has already been tried, but the first were not well tolerated or were even toxic. Currently, these plasters are made of biodegradable proteins, which have variable clinical results. These is because they are mainly intended to support the healing process, and dissolve too quickly when in contact with digestive juices and don’t always hold tight. “Leaks after abdominal surgery are still one of the most feared complications today,” explained Empa researcher Inge Herrmann, who is also professor for nanoparticulate systems at ETH Zurich.

Searching for a material that could reliably seal intestinal injuries and surgical wounds, Hermann’s team found a synthetic composite material made up of four acrylic substances that, together, form a chemically stable hydrogel. Additionally, the patch actively cross-links with the intestinal tissue until it is fluid-tight. The quadriga of acrylic acid, methyl acylate, acrylamide and bis-acrylamide works in perfect synergy, as each component conveys a specific feature to the final product: a stable bond to the mucosa, the formation of networks, resistance to digestive juices and hydrophobicity. This new technology is detailed in Advanced Functional Materials.

In lab experiments, the researchers found the polymer system met their expectations. “Adhesion is up to ten times higher than with conventional adhesive materials,” said researcher Alexandre Anthis from Empa’s Particles-Biology Interactions lab in St. Gallen. “Further analysis also showed that our hydrogel can withstand five times the maximum pressure load in the intestine.” The material’s design uses its tailored effect: The rubbery composite selectively reacts with digestive juices that might leak through intestinal wounds, expands and closes all the more tightly. The inexpensive, biocompatible super glue, could thus shorten hospital stays and save healthcare costs, and Anthis is making plans to bring it to market.

Source: Empa

New Medical Device Slashes Surgery Risk

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A new electromedical device provides important data about possible cardiovascular and pulmonary risks before an operation.

Before any operation, it is important to properly assess the individual risk: Are there perhaps circulatory or pulmonary problems that need special consideration? To what extent can special risks be taken into account when planning the anaesthesia? Previously, clinicians have had to rely on rather subjective empirical values or carry out more elaborate examinations when in doubt. To address this, a novel device has been developed by TU Wien and MedUni Wien to objectively measure the cardiovascular and pulmonary system fitness of patients.

Pre-op interviews are important—but subjective
Complications often occur after surgical interventions. In addition to blood loss and sepsis, perioperative cardiovascular and pulmonary problems are among the most common causes of death in the first 30 days after surgery.

To minimise this risk, anesthesiologists routinely talk to patients before surgery, in addition to measuring their blood pressure, performing an electrocardiogram, or conducting more laborious examinations. But assessing responses can be highly individualised. “There are also objectively measurable parameters by which one could easily identify possible risks,” said Prof Eugenijus Kaniusas (TU Wien, Faculty of Electrical Engineering and Information Technology). “So far, however, they have not been routinely measured.”

Just hold your breath
This new device uses multiple sensors to determine key metrics in a completely non-invasive way. All the patient has to do is hold their breath for a short time to slightly outbalance their body, which responds reflexively with various biosignals. “Holding your breath is a mild stress for the body, but that is already enough to observe changes in the regulatory cardiovascular and pulmonary systems,” explained Eugenijus Kaniusas. “Oxygen saturation in the blood, heart rate variability, certain characteristics of the pulse waveform—these are dynamic parameters that we can measure in a simple way, and from them we could ideally infer individual fitness in general, especially before surgery.”

Since the device is non-invasive, medical training is not needed to operate it, and has no side effects. The result is easy to read: A rough assessment according to the three-color traffic light system or a score between 0 and 100 is displayed. The measurement can also be carried out at the bedside without any problems for people with limited mobility.

“Our laboratory prototype is being tested at MedUni Wien in cooperation with Prof. Klaus Klein from the University Department of Anesthesia, General Intensive Care Medicine and Pain Therapy. We hope to bring the device to market in the next 5 years with the help of research and transfer support,” said Eugenijus Kaniusas.

Source: Vienna University of Technology

Transcranial Focused Ultrasound for Chronic Pain Relief

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A rodent study has demonstrated the potential for transcranial focused ultrasound (tFUS) to relieve chronic pain and other symptoms.

Neuromodulation, or therapeutic stimulation of neurons with electrical energy. chemicals or potentially with acoustic waves, can amplify or dampen neuronal impulses in the brain or body to relieve symptoms such as pain or tremor.

Ultrasound is a promising non-invasive, non-surgical type of neuromodulation. It offers a temporary modulation that can be tuned for a desired effect. In this study, researchers have shown that it can be targeted at neurons with specific functions.

A team led by Bin He, PhD, professor of biomedical engineering at Carnegie Mellon University, and funded in part by the National Institute of Biomedical Imaging and Bioengineering (NIBIB), has demonstrated the potential of a neuromodulation approach that uses low-intensity ultrasound energy, called transcranial focused ultrasound-;or tFUS. In a paper published in Nature Communications, the authors describe the use of tFUS in rodent experiments, demonstrating the non-invasive neuromodulation alternative.

Moria Bittmann, PhD, Director of the Program in Biorobotic Systems, National Institute of Biomedical Imaging and Bioengineering, said: “Transcranial focused ultrasound is a promising approach that could be used to treat forms of chronic pain, among other applications. In conditions where symptoms include debilitating pain, externally generated impulses of ultrasound at controlled frequencies and intensity could inhibit pain signals.”

The researchers designed an assembly that included an ultrasound transducer and a multi-electrode array, which records neuronal data. During experiments with anaesthetised rodents, the researchers sent acoustic pulses into the brain cortex, targeting specific neurons, while recording change in electrophysiological signals from different neuron types.

When neurons transmit signals, whether engaging the senses or controlling movement, the firing of that signal across the synapse is termed a spike. The researchers observed two types of neurons: excitatory and inhibitory neurons.

When using tFUS to emit repeated bursts of ultrasound stimulation directly at excitatory neurons, the researchers saw an elevated impulse rate, or spike. Inhibitory neurons subjected to the same tFUS energy however did not display a significant spike rate disturbance. This showed that the ultrasound signal can be transmitted through the skull to selectively activate specific neuron sub-populations, in effect targeting neurons with different functions.

“Our research addresses an unmet need to develop non-toxic, non-addictive, non-pharmacologic therapies for human use,” said Prof He. “We hope to further develop the tFUS approach with variation in ultrasound frequencies and to pursue insights into neuronal activity so that this technology has the optimal chance for benefiting brain health.”

There are many broad applications for this research. Prof He believes non-invasive tFUS neuromodulation could be used to facilitate treatment for many people suffering from pain, depression and addiction. “If we can localise and target areas of the brain using acoustic, ultrasound energy, I believe we can potentially treat a myriad of neurological and psychiatric diseases and conditions,” Prof He said.

Source: National Institute of Biomedical Imaging and Bioengineering

The Promise of Plant-based Vaccines

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Recent advances in the development and testing of plant-made vaccines has rekindled interest in plant-produced pharmaceuticals, including edible drugs, for human use. Technology and manufacturing advances could boost the uptake of such therapeutics, wrote Hugues Fausther-Bovendo and Gary Kobinger in an article published in Science

Currently, therapeutic proteins such as antibodies, hormones, cytokines, and proteins in vaccines are mostly produced in bacteria or eukaryotic systems, including chicken eggs and mammalian or insect cell cultures. In 1986, scientists proposed the use of plants for the production of these proteins in what is termed ‘molecular farming’. Such a production process can be less costly and produce fewer contaminants. 

Thus far, just one therapeutic protein derived from plants for human use has been approved (in 2012, for Gaucher disease). More recently in 2019, a plant-produced influenza virus vaccine completed phase III clinical trials with promising results, and phase III trials for a plant-made vaccine COVID vaccine started in early 2021. Plant-produced proteins have a number of advantages for vaccine development, according to Fausther-Bovendo and Kobinger, in particular the strong immune response the plant components of virus-like particles in vaccines can generate, which may reduce the need for adjuvants. 

Also interesting to consider are oral, plant-made therapeutics, said Fausther-Bovendo and Kobinger. Possibly needing minimal processing, they could avoid expensive, lengthy manufacturing. 

Edible vaccines – still predominantly in the preclinical stage of development – are also currently under development, the authors note. Compared to the proof-of-concept edible vaccines first tested decades ago, which generated weak immune responses, newly developed edible plant-made vaccines are now capable of provoking stronger immune responses, thanks to improved technology. 

Because doses for therapeutics are much higher than for vaccines, investment in manufacturing infrastructure must increase to achieve large-scale manufacturing of plant therapeutic products, Fausther-Bovendo and Kobinger said.

Source: EurekAlert!

Tiny Generators Tap Body Motion for Medical Applications

Researchers have created biocompatible generators which harvest body motion to produce electrical impulses for medical applications such as wound healing.

Piezoelectric materials such as ceramics and crystals can generate an electrical charge when mechanically stressed, and are used in many devices such as ultrasound transducers, vibration sensors, and cell phones. In medicine, electrostimulation using piezoelectric devices has been shown to be beneficial for accelerating wound and bone fracture healing, maintaining muscle tone in stroke victims, and chronic pain reduction. However, lack of biocompatibility has stalled progress in the field.

Now bioengineers at the University of Wisconsin’s Department of Materials Science and Engineering, led by Professor Xudong Wang, have developed implantable piezoelectric therapeutic devices. These thin, flexible devices make use of the piezoelectric properties of non-rigid, nontoxic biological materials such as silk, collagen, and amino acids.
The team came up with a method for self-assembly of small patch-like constructs that use the amino acid lysine as the piezoelectric generator. The self-assembly process incorporates a biocompatible polymer shell that surrounds the lysine as the polymer/lysine solution evaporates. Chemical interactions between the inner layer of lysine and the polymer coating orient the lysine into the crystal structure necessary for it to produce electric current when flexed.

“This work is an outstanding example of using the chemical properties of the materials to create a self-assembling product,” explained David Rampulla, director of the Division of Discovery Science and Technology at the National Institute of Biomedical Imaging and Bioengineering. “The process used is rapid and inexpensive, making production of such wafers for therapeutic applications feasible. That the wafers are biodegradable opens the possibility for creating electrotherapies that could be used to accelerate healing of an injured bone or muscle, for example, and then degrade and disappear from the body.”

In one of a number of tests, wafers were placed in the leg and chest of rats, movements of which compressed the piezoelectric wafers enough to create an electrical output. Blood tests performed after the transplanted wafer dissolved showed normal levels of blood cells and other metabolites, indicating no harmful effects from the dissolved device.

Prof Wang emphasises the simplicity of the elegant work. “We believe the technology opens a vast array of possibilities including real-time sensing, accelerated healing of wounds and other types of injuries, and electrical stimulation to treat pain and other neurological disorders. Importantly, our rapid self-assembling technology dramatically reduces the cost of such devices, which has the potential to greatly expand the use of this very promising form of medical intervention.”

The results were reported in the journal Science.

Source: Medical Xpress