Tag: medical tech

New Type of Sensor ‘Bandage’ Alerts Clinicians to Pressure Sores

A new type of wearable sensor ‘bandage’ that can monitor blood oxygenation is being developed.

Driven partly by the growing interest in telemedicine as a result of COVID researchers at Missouri S&T are working on a printable, flexible, disposable sensor that can interact with a smartphone. This new kind of inexpensive sensor could alert health care workers early on to developing conditions such as pressure ulcers. Pressure ulcers normally develop from ischaemia caused by pressure and shear, and often occur in hospitalised patients or bedridden patients at home.

“Our current work focuses on designing and optimising a tissue oxygen sensor by using inexpensive inkjet printing techniques,” said Dr Chang-Soo Kim, professor of electrical and computer engineering at Missouri S&T. “Concurrently, we are developing a smartphone app that can interpret sensor images. This prototype will be evaluated using phantom tissue that mimics a pressure ulcer site.”

Dr Kim is working with other researchers to create a cheap, easy-to-use sensor to help prevent pressure sores which are on the rise due to obesity and diabetes. This might speed recovery, reducing the length of hospital stays and saving millions of dollars. 

Current pressure ulcer monitoring involves manual examination, but with this wearable sensor, drops in oxygen levels are sensed at the at-risk site before they have a chance to turn into a sore. The change could even be detected at home, in say a foot ulcer, alerting a clinician via smartphone who could then provide a diagnosis. 

“Our optical sensor bandage functions by detecting a low skin oxygen level caused by compromised circulation,” said Kim. “This low oxygen produces a color change called luminescence intensity. The smartphone can then take a photograph of the dressing and transmit it to enable remote monitoring or encourage timely intervention before major skin decomposition occurs.”

Source: Medical Xpress

New Ultrasonic Tumour Therapy

A new technique has been developed that uses ultrasound to vapourise encased nano-droplets, at the tumour site. This technology could be used to image the tumour, damage it or even deliver chemotherapy drugs with precision.

Existing applications of ultrasound therapy include thermal excitation of tissues, for example to dilate blood vessels, and creating cavitation to break up kidney stones. Ultrasonic toothbrushes have also been shown to remove dental plaque with better efficiency than conventional toothbrushes, and about the same as that of mechanical electrical toothbrushes. Micrometre-sized droplets, encased in a stabilising shell, can already be visualised with ultrasound, but these are too large to enter tumours. Nanometre-sized droplets can do so, however.

Vapourisation is tricky to control in reality, since the process requires a point of nucleation. The researchers demonstrated an efficient way to achieve vapourisation: by applying a frequency at the exact resonant frequency of the droplet, the pressure inside suddenly drops and the liquid vapourises. This is much the same principle as shattering a crystal glass by bombarding it with sound at its resonant frequency.

The researchers used hydrofluorocarbons,  which have a very low boiling point,   for the droplets. The resonance of the droplet being six times higher makes vapourisation much easier. The speed of sound of the droplet fluid being lower than the speed of sound in the bodily fluids surrounding it.
This resonant droplet vapourisation technology has a number of possible medical applications. The bubbles from the bursting droplets could be used to physically damage the tumour. Or, the droplets could contain chemotherapy drugs and made to break open precisely inside the tumour and reducing exposure of the rest of the body.

Source: News-Medical.Net

Journal information: Lajoinie, G. et al. (2021) High-Frequency Acoustic Droplet Vaporization is Initiated by Resonance’ by Guillaume Lajoinie, Tim Segers, and Michel Versluis. Physical Review Letters. doi.org/10.1103/PhysRevLett.126.034501.

Paralysed Mice Walk Again with ‘Designer’ Cytokines

Scientists have sought a means to regenerate spinal cord injuries which leaves patients paraplegic or quadriplegic – and now a breakthrough by researchers at Ruhr-University Bochum, Germany, may see that dream realised.

By the time humans reach adulthood, after an injury they can no longer regenerate the axons which transfer nerve impulses from brain to muscles. In 2013, the researchers discovered that a cytokine called interleukin-6 (IL-6) promoted the regeneration of optic axon fibres in vitro. IL-6 was known to be involved in nerve regeneration as well as in neuropathic pain from peripheral nerve injuries. As promising as this experiment was, delivery of the cytokine to the injury location deep in the body was an obstacles, as was the fact that it had a fairly weak effect on stimulating nerve tissue regrowth.

The team subsequently developed hyper-IL-6, an artificial variant of IL-6 that was far more potent than its natural counterpart. However, the “designer” cytokine still could not be delivered to the injured tissue where it was needed. To get around this, the researchers turned to a somewhat novel delivery method: gene therapy. A few motor neurons in the brain’s sensorimotor cortex are altered via engineered viruses to produce hyper-IL-6, which is then distributed along the axon’s length to the injury site.

“Thus, gene therapy treatment of only a few nerve cells stimulated the axonal regeneration of various nerve cells in the brain and several motor tracts in the spinal cord simultaneously,” explained senior author Dr Dietmar Fischer.

After a single injection of the engineered virus and its hyper-IL-6 payload, mice with severed spinal cords were able to walk again after two to three weeks.

“This came as a great surprise to us at the beginning, as it had never been shown to be possible before after full paraplegia,” said Dr. Fischer.
Following the success of these experiments, Dr. Fischer’s team is looking at combining the engineered cytokine treatment to other promising applications, such as tissue grafts. Additionally, they are investigating whether the hyper-IL-6 treatment can regenerate spinal cord damage that occurred weeks beforehand.

“This aspect would be particularly relevant for application in humans. We are now breaking new scientific ground. These further experiments will show, among other things, whether it will be possible to transfer these new approaches to humans in the future.”

However, adapting this designer cytokine treatment to be one that is safe for humans will take several years.

Source: Medical News Today

New Type of Corneal Implant Fuses into the Eye

A new type of artificial cornea has been successfully implanted into an elderly patient, who demonstrated recovered sight the day after his surgery.

When the cornea is damaged by disease or injury, blindness can result, necessitating a cornea transplant. Artificial corneas are a much sought-after technology, as the normal treatment for a damaged cornea is to seek a transplanted replacement. However, for every 70 corneas sought, there is only a single donor cornea. CorNeat Vision is set to offer the first commercially available synthetic cornea implant, the KPro.

The new cornea has a clear centre section, surrounded by a white skirt consisting of electrospun nanofibres. Electrospun nanofibres have already found application in many medical applications, such as a new kind of translucent burn dressing. This skirt’s nanofibre material allows fibroblasts and collagen to infiltrate its structure, allowing full integration within a few weeks of surgery. This biomimetic technology results in faster healing times, the ability to use fully synthetic implants and is fully scalable as it does not rely on any harvested tissue.

The implantation procedure involves removing the epithelium covering the cornea, marking the location of where the artificial cornea implant should go, removing the cornea and then suturing its replacement into position.

Only a day after his surgery, the first recipient of this new artificial cornea was able to make out the faces of his relatives and read numbers off of a chart.

Source: Medical Xpress

Exoskeleton Technology Evaluated for Nursing Care

A new article from the journal Ergonomics in Design reported on research by Tampere University into how exoskeleton technology can help reduce the physical burden of nurses.

Postdoctoral Research Fellow Tuuli Turja said, “This message from the field led us to investigate what conditions exoskeletons would need to meet in order to reform nursing. Currently, exoskeletons are mainly used in manufacturing and logistics. Isn’t it high time to introduce exoskeletons in female-dominated sectors, where musculoskeletal disorders are rampant?” she continues. “However, in our study, a very different type of mobile and light exoskeleton was worn by nurses in patient care.”

Two studies evaluated the Laevo Exoskeleton, which is a “passive” device designed to distribute loads across the body via interconnected pads on the back, chest and thighs. According to the manufacturer, it is designed to reduce lower back strain by 40 to 50%. For the first study, pairs of nurses helped elderly patients to wheelchairs from their hospital beds, with and without use of the exoskeleton. In the second study, seven nurses wore the exoskeleton in a real care environment.

The results show that although the nurses were amenable to their use, exoskeletons need specific designs when it comes to the challenges of patient care, such as comfort, interactive features and safety to help them through hectic workloads.

Source: Science Daily

New Plasma Jet Sterilises Surfaces but Doesn’t Get Hot

Researchers at University of California, Los Angeles (UCLA) have developed a novel way to sterilise surfaces – using a jet of glowing plasma.

The team created a tool which emits plasma, generated from an electric arc and a supply of harmless argon, but only at room temperature. However, their study, testing the plasma jet on a series of different materials, has shown that it can sterilise surfaces of the COVID virus within 30 seconds

Unlike other sterilisation solutions, such as chemicals or UV light, the plasma is completely harmless, with the only inputs being electricity and air – argon makes up 1% of the air we breathe. It was even able to sterilise surfaces such as cardboard, which would be difficult to sterilise with traditional chemicals without slightly damaging it.  

A relatively new technology, “cold” plasma has been used in a variety of medical applications, including cancer surgery, dentistry and wound healing.

Author Richard E. Wirz said the results show that plasma has a great role to play in potentially breaking the transmission of COVID/

“This is only the beginning. We are very confident and have very high expectations for plasma in future work. In the future, a lot of answers for the scientific community will come from plasma,” said Wirz.

Source: Phys.org

New Multi-cancer Blood Test Offered by NHS

A new blood test developed by the California-based Grail company tests for DNA methylation, and is supposedly able to screen for over 50 cancer types this way.

The NHS is to offer the test to 165 000 people from the middle of next year, with 140 000 screened through their medical records and the remaining 25 000 through referrals from suspected symptoms. It is hoped that widespread screening and early detection will drastically improve cancer survival rates, consequently easing pressure on healthcare services.

Lawrence Young, a professor of molecular oncology, at Warwick University, said the Galleri test was one of several novel blood tests being developed to spot cancer early on. “A publication from the Circulating Cell-free Genome Atlas consortium examining the Galleri test in 6 689 participants has generated very encouraging results in more than 50 different cancers at different stages of development.”

However, there was disagreement from some cancer experts regarding Galleri’s  potential effectiveness. Paul Pharoah, a professor of cancer epidemiology, at Cambridge University, said that it was premature for the NHS to embrace an unproven test. He said, “The Galleri blood test is a test that might be able to detect cancer in the blood in individuals with early cancer, though the evidence that it does this effectively is weak,” Pharoah said. According to him, only a single published paper on the tests was available, wherein they detected a mere 25% of early-stage cancers and under half of late-stage cases.

Source: The Guardian

New Minimally Invasive Way to Sample Interstitial Fluid

A new method to extract dermal interstitial fluid (ISF) for analysis has been reported. ISF contains a large number of biomarkers which can be used for diagnosis.

The minimally invasive process uses an array of almost invisibly small needles, approximately one quarter of a millimetre long. These were pressed to the skin and suction applied. Care needed to be taken so that the needles did not poke into microcapillaries in the skin and thus contaminate the sample with blood. 

Blood is often used for testing, comprising some 6% of the human body’s fluids, but some 10 000 compounds are found in ISF and 12% of the chemicals are not found in the blood. With the technique, the researchers were also able to measure the effects of glucose and caffeine, which are dynamically active. Traditional methods used to extract are quite invasive; using a needle to withdraw ISF from a vacuum-induced blister, or surgically inserting tubes underneath the skin.

Although the procedure is still time consuming, taking some 20 minutes per patient, it compares to the ~40 minutes required to form a vacuum blister in some ISF sampling protocols. The small needle injuries healed within a day, and there was minimal irritation.

This form of testing could have many applications, such as skin toxicological studies and monitoring glucose levels.

The journal article has been published in Science Translational Medicine.

Source: News-Medical.Net

Simple New Method to Improve Time Release of Drugs

Researchers have developed a new method to measure the release of drugs over time, using a simple method.

OxyContin, containing the opiate oxycodone, was intended to offer 12-hour pain relief. Instead, in some patients it dissolved much more quickly, causing them to take it more frequently and ultimately become addicted. But assessing how a drug dissolves in the body is surprisingly tricky. Drug dissolution has to be measured under laboratory conditions that come as close as possible to mimicking what happens in the body.

Corresponding author William Grover, associate professor of bioengineering at the Marlan and Rosemary Bourns College of Engineering explains: “We directly measured dissolution profiles of single drug granules, which are the little spheres you see when you open up a capsule. We accomplished this using a vibrating tube sensor, which is just a piece of glass tubing bent in the shape of a tuning fork.”

Many factors influence the way a drug is dissolved in the body, such as the chemical composition and pH of the fluid, the patient’s sex and their metabolism. Meals taken also have a strong impact: taking a fatty meal increases the amount of oxycodone released from OxyContin by 25%.

Pharmaceutical companies simulate these conditions in test vessels to build a profile of how the drug works over time, but this has its drawbacks. The position of tablets in the vessels can affect dissolution rates; equipment can become clogged; the process is very time-consuming and they only provide brief snapshots over time.

The new approach takes a radically different approach, measuring the mass of a drug granule as it dissolves. This is accomplished by changes in the resonant frequency, which can be measured over time instead of being sampled.

Using the technique on three proton-pump inhibitors, the researchers found considerable variations between name-brand and generic formulations of the drugs, affecting the rate at which the drugs are absorbed by patients.

“Our technique is much cheaper and easier to perform than conventional methods, and that enables pharmaceutical companies to do more tests in a wider variety of conditions,” said Grover. “We can also easily see differences in dissolution between individual particles in a drug. That should help pharmaceutical companies improve and monitor the consistency of their manufacturing processes.”

Source: Medical Xpress

AI Solutions Are No Magic Bullet Against COVID

A leading researcher in the field of medical image analysis has cautioned against the rush to provide AI solutions to the COVID pandemic, arguing that the need to help out must not compromise scientific principles.

Prof Hamid Tizhoosh, head of KIMIA Lab, Faculty of Engineering at the University of Waterloo wrote a piece on Medical-News.Net where he laid out the problems involved in such “quick fix” solutions.

He explains that AI researchers often make “toy” datasets which they use to experiment with in their own labs. In the middle of the pandemic, it is difficult to collaborate with radiographers who have their hands full dealing with COVID patients’ images.

AI research requires the acquisition and curation of large amounts of high-quality data, and currently there is an absence of this. While there are still few publicly available X-ray images or CT images of COVID patients’ lungs, they are beginning to crop up on the internet. AI researchers and enthusiasts are scraping together these images for their data sets and supplementing them with those of pneumonia patients, which are much more readily available. The results of their AI work are being released in papers that are not peer reviewed, yet some claim to be authoritative solutions.

Tizhoosh draws attention to the validity of this data. In one instance, he saw that the data included a pneumonia case from a paediatric patient. He cautions that, “AI is neither a ventilator nor a vaccine nor a pill; it is extremely unlikely that the exhausted radiologists in Wuhan, Qom or Bergamo download the Python code of our poorly trained network (using insufficient and improper data and described in quickly written papers and blogs) to just obtain a flawed second opinion.”

He concludes that the AI developments must come after appropriate images are made available by hospitals, that ethics approval is received and the data is properly de-identified.