Conformable AlN Piezoelectric Sensors as a Non-invasive Approach for Swallowing Disorder Assessment.

Deglutition disorders (dysphagia) are common symptoms of a large number of diseases and can lead to severe deterioration of the patient's quality of life. The clinical evaluation of this problem involves an invasive screening, whose results are subjective and do not provide a precise and quantitative assessment. To overcome these issues, alternative possibilities based on wearable technologies have been proposed. We explore the use of ultrathin, compliant, and flexible piezoelectric patches that are able to convert the laryngeal movement into a well-defined electrical signal, with extremely low anatomical obstruction and high strain resolution. The sensor is based on an aluminum nitride thin film, grown on a soft Kapton substrate, integrated with an electrical charge amplifier and low-power, wireless connection to a smartphone. An ad-hoc designed laryngeal motion simulator (LMS), which is able to mimic the motions of the laryngeal prominence, was used to evaluate its performances. The physiological deglutition waveforms were then extrapolated on a healthy volunteer and compared with the sEMG (surface electromyography) of the submental muscles. Finally, different tests were conducted to assess the ability of the sensor to provide clinically relevant information. The reliability of these features permits an unbiased evaluation of the swallowing ability, paving the way to the creation of a system that is able to provide a point-of-care automatic, unobtrusive, and real-time extrapolation of the patient's swallowing quality even during normal behavior.

Influence of Nanofiber Orientation on Morphological and Mechanical Properties of Electrospun Chitosan Mats.

This work explored the use of chitosan (Cs) and poly(ethylene oxide) (PEO) blends for the fabrication of electrospun fiber-orientated meshes potentially suitable for engineering fiber-reinforced soft tissues such as tendons, ligaments, or meniscus. To mimic the fiber alignment present in native tissue, the CS/PEO blend solution was electrospun using a traditional static plate, a rotating drum collector, and a rotating disk collector to get, respectively, random, parallel, circumferential-oriented fibers. The effects of the different orientations (parallel or circumferential) and high-speed rotating collector influenced fiber morphology, leading to a reduction in nanofiber diameters and an improvement in mechanical properties.