March 30, 2020
Enjoy these interesting stories from the scientific community.
*-- Study: New imaging technology tops ECG for irregular heartbeat diagnosis --*
A new ultrasound imaging approach may help improve diagnosis of cardiac arrhythmia, or irregular heartbeat, a new study suggests.
In findings published Wednesday in Science Translational Medicine, researchers from the Department of Biomedical Engineering and the Cardiac Electrophysiology Laboratory at Columbia University Medical Center demonstrated electromechanical wave imaging, a non-invasive approach that uses ultrasound to detect changes in heart contractions, was more than 96 percent accurate in spotting irregular heartbeat.
In comparison, electrocardiogram, or ECG, which is currently the most commonly used approach in the diagnosis of arrhythmia, has been estimated to have a 71 percent accuracy.
"Using electromechanical wave imaging as a clinical visualization tool in conjunction with ECG could improve planning discussions with patients about treatment options and pre-procedural planning, as well as potentially reducing redundant ablation sites, prolonged procedures and anesthesia times," co-author Dr. Elisa E. Konofagou, a professor of biomedical engineering and radiology at Columbia University, told UPI.
According to the American Heart Association, millions of people in the United States live with arrythmias, including tachycardia and atrial fibrillation, or A-Fib. Some 3 million Americans have A-Fib.
Arrythmias can be controlled with medication, or treated with surgery, like catheter ablation, in which the tissue causing the irregular heartbeat is removed. Surgeons may also recommend the implantation of a device designed to control heartbeat, typically a pacemaker or implantable cardioverter defibrillator.
Study co-author Dr. Elaine Wan, a cardiologist at Columbia University Medical Center, told UPI that the current approach for diagnosing arrythmias, ECG, which has been used since the 19th century, uses invasive catheterization to map abnormal heart rhythm. She noted that the procedure can also take several hours to complete.
ECGs are also subject to interpretation from the test operator, meaning that clinicians can end up with inconsistent results and diagnoses.
After first testing electromechanical wave imaging in dogs, the researchers tested the approach in 55 patients with cardiac arrythmias, including those caused Wolff-Parkinson-White syndrome, atrial tachycardia and premature ventricular complexes.
The scientists found that by performing electromechanical wave imaging in all four chambers of the heart, they were able construct three-dimensional maps that revealed which areas of the organ were causing the arrhythmia in study participants.
"We were able to show that not only does our imaging method work in difficult cases of arrhythmia, but that it can also predict the optimal site of radiofrequency ablation before the procedure where there is no other imaging tool available to do that in the clinic," Konofagou said.
The next steps, Wan said, are to see if the method can reduce procedure time, patient risk and improve outcomes.
*-- Scientists unveil smaller, more powerful brain-machine interface --*
 Researchers have developed a new brain-machine interface that allows the human brain to link directly with silicon-based technologies. The novel device is less intrusive and more powerful -- able to capture more detailed neural activity data -- than similar kinds of technology.
Scientists described the new device in the journal Science Advances.
"Nobody has taken these 2D silicon electronics and matched them to the three-dimensional architecture of the brain before," study co-author Abdulmalik Obaid, graduate student in materials science and engineering at Stanford University, said in a news release. "We had to throw out what we already know about conventional chip fabrication and design new processes to bring silicon electronics into the third dimension. And we had to do it in a way that could scale up easily."
The device features a bundle of extremely thin wires that are implanted into the brain. The tiny wires measure the electrical signals of different parts of the brain and relay the information to a silicon chip on the outside.
"Electrical activity is one of the highest-resolution ways of looking at brain activity," said co-author Nic Melosh, professor of materials science and engineering at Stanford. "With this microwire array, we can see what's happening on the single-neuron level."
Using mouse models, scientists successfully captured a range of brain signals using the brain-machine interface.
The authors of the new study wanted to incorporate silicon into their device because silicon technologies are so abundant. The inclusion could allow their device to be integrated with a variety of communication and data processing technologies.
"Silicon chips are so powerful and have an incredible ability to scale up," said Melosh. "Our array couples with that technology very simply. You can actually just take the chip, press it onto the exposed end of the bundle, and get the signals."
Because the wires are so delicate, scientists needed to bundle them in a biologically-safe polymer outside of the brain. The bottom half of the bundle is polymer-free, allowing the individual wires to be precisely directed into different parts of the brain.
"The design of this device is completely different from any existing high-density recording devices, and the shape, size, and density of the array can be simply varied during fabrication," said co-author Jun Ding, assistant professor of neurosurgery and neurology. "This means that we can simultaneously record different brain regions at different depths with virtually any 3D arrangement."
"If applied broadly, this technology will greatly excel our understanding of brain function in health and disease states," Ding said.
In the future, scientists suggest the technology could be used to bolster medical therapies, including prosthetics and speech assistance.
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