Toho University

A team of researchers has proposed a new concept for magnet-based memory devices, which might revolutionize information storage devices owing to their potential for large-scale integration, non-volatility, and high durability. A team of researchers has proposed a new concept for magnet-based memory devices, which might revolutionize information storage devices owing to their potential for large-scale integration, non-volatility, and high durability. Details of their findings were published in the journal Nature Communications on March 7, 2024. Spintronic devices, represented by magnetic random access memory (MRAM), utilize the magnetization direction of ferromagnetic materials to memorize information. Because of their non-volatility and low energy consumption, spintronic devices will likely play a pivotal role in future information storage components. However, ferromagnet-based spintronics devices have a potential pitfall. Ferromagnets generate magnetic fields around them, which affect nearby ferromagnets. In an integrated magnetic device, this results in crosstalk between magnetic bits, which will limit the magnetic memory density. The research team, which comprised Hidetoshi Masuda, Takeshi Seki, Yoshinori Onose and others from Tohoku University's Institute for Materials Research, and Jun-ichiro Ohe from Toho University, demonstrated that magnetic materials called helical magnets can be utilized for a magnetic memory device, which should resolve the magnetic field problem. In helical magnets, the directions of the atomic magnetic moments are ordered in a spiral. The right- or left-handedness of the spiral, called chirality, could be utilized to memorize the information. The magnetic fields induced by each atomic magnetic moment cancel each other out, so the helical magnets do not generate any macroscopic magnetic field. "The memory devices based on the handedness of the helimagnets, free from the crosstalk among bits, could pave a new pathway for improving the memory density," says Masuda. The research team demonstrated that the chirality memory can be written and read out at room temperature. They fabricated epitaxial thin films of a room-temperature helimagnet MnAu2 and demonstrated the switching of chirality (right- and left-handedness of the spiral) by the electric current pulses under magnetic fields. Furthermore, they fabricated a bilayer device composed of MnAu2 and Pt (platinum) and demonstrated that the chirality memory can be read out as a resistance change, even without magnetic fields. "We have uncovered the potential capability of chirality memory in helical magnets for next-generation memory devices; it may offer high-density, non-volatile, and highly stable memory bits," adds Masuda. "This will hopefully lead to future storage devices with ultrahigh information density and high reliability."

Singaporean medical technology firm Aevice Health and the National University Health System have announced their partnership to conduct a clinical trial of the former's wearable respiratory monitor. The AI-powered wearable stethoscope AeviceMD remotely detects and records chest sounds at the same time. The sounds are then analysed and translated into heart rate and respiratory rate measurements while flagging abnormalities such as wheezing. WHY IT MATTERS NUHS noted that one in five children in Singapore has asthma, one of the most prevalent chronic diseases affecting 14% of children worldwide. The condition can be "difficult to manage" when children are not able to communicate their symptoms or realise they are experiencing them, leading to "under-diagnosis, under-treatment and inadequate control of the disease". The healthcare group, through its Centre for Innovation in Healthcare, will investigate the use of AeviceMD in detecting wheezing, one of the key signs of asthma, in children patients with breathing difficulties at the National University Hospital. It already recruited participants in September and is targeting to finish the study by the second quarter of 2022. Dr Michael Lim, the study's principal investigator, said the respiratory monitor by Aevice Health "can potentially enhance remote patient monitoring and may be useful in situations such as the current COVID-19 pandemic where there is a need to minimise contact with patients. The NUH senior consultant also pointed out that its "ability to detect abnormal lung sounds may also find usefulness in homes to identify wheezing early in children and allow for prompt attention by the caregiver". THE LARGER TREND Aevice Health is also researching and developing a predictive model for asthma attacks in paediatric patients using a wearable continuous monitoring device. In other news, the company in June secured over $2 million in a pre-Series A funding round joined by Toho Holdings and SEEDS Capital of Enterprise Singapore, among others. The proceeds from the investing event were set aside for the development of its respiratory monitoring solution and its entry into Japan. Aevice Health has entered into a strategic partnership with medical products wholesaler Toho Holdings to market AeviceMD in Japan. ON THE RECORD "This study will further validate AeviceMD’s value to providers and patients by empowering the detection of lung sound abnormalities objectively, continuously, and remotely to further bridge the gap between providers and clinicians," said Aevice Health CEO Adrian Ang. "The use of AeviceMD as a novel remote respiratory monitor can unlock insights beyond the hospital for providers to better understand factors leading up to an exacerbation to allow for more tailored and patient-centred outcomes. We are excited by how the use of the AeviceMD can enhance the way chronic respiratory diseases [are] being treated and understood," he added.

Japanese researchers have created a catheter that can navigate by itself through some of the thinnest branches of the bronchi. Pulmonary lesions are biopsied to diagnose or treat respiratory illnesses like lung cancer. Bronchoscopy is the standard method for manual biopsies. The bronchi branches into different directions and progressively gets thinner and more difficult to navigate. The propelling movement for catheters and endoscopes during traditional bronchoscopy makes it harder for doctors to reach troublesome lesions with biopsy forceps, which can result in false diagnostics. Yuichiro Takai, professor in the department of respiratory medicine at Omori Medical Center at Toho University, and Hideyuki Tsukagoshi, a member of the department of system and control engineering at Tokyo Tech, developed a self-propelling catheter that creates traveling waves in multiple chambers by adding and reducing pressure inside a tube. The catheter moves forward in a peristaltic motion that is similar to the way an earthworm moves. It can move through the small structures of the bronchi and can curve to choose the direction of propulsion. The researchers tested the catheter on a bronchus model. The researchers hope to increase the accuracy of which way the catheter can be propelled. They also want to fit the catheter with a camera to be able to get information on the inside of the bronchi, create functions used for biopsies and treatment and give instruments a practical use.