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

Abstract

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.

Heat-Resistant, Flexible Piezoelectric Sheet Sensors Based on Solution-Processed Zinc Oxide Films for In-Vehicle Driver Monitoring Applications

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Leveraging IoT-Aware Technologies and AI Techniques for Real-Time Critical Healthcare Applications

“…Various sensing technologies can be used to collect data relevant to the specific health-related parameters of interest applicable to the use case to which the architecture will be applied. For example, for a cardiac-related AAL application, a combination of skin-compatible piezoelectric or piezoresistive sensors defined in [ 31 , 32 , 33 , 52 , 53 ] in conjunction with motion, temperature, or positioning sensors, which add contextual information to the physiological measurements, can be used in this layer. The usage of flexible sensors can fulfil NFR3 and facilitate the development of comfortable and reliable wearable devices suitable for long-term surveillance of critical parameters in prevention, diagnosis, and rehabilitation use cases in the healthcare domain.…”

Inkjet-printed flexible piezoelectric sensor for self-powered biomedical monitoring

“…Ferroelectric polymers are piezoelectric, which means that they can convert mechanical stress into electric field and vice versa [18]. Piezoelectric materials are crucial components in electronic industry, which are extensively used in fabrication of sensors, energy harvesters, ultrasonic transducers, sonars systems, actuators, and self-powered devices [19][20][21][22].…”

“…At bending angles around 30º the signal peaked at around 0.3 V, while at 90º the peak voltage was around 1.0 V. The bending signals were comprised of positive and negative pulses corresponding to finger bending and finger straightening, respectively. Swallowing disorders also known as dysphagia are common symptoms of several diseases that can cause malnutrition and deterioration of patient´s life quality [22]. Swallowing is always accompanied with laryngeal movement, which can be converted into electric signals by using a conformable piezoelectric sensor.…”

“…Each swallowing signal was comprised of two phases, corresponding to upward and downward laryngeal prominence excursions. The first phase of the signal was corresponded to the moment that laryngeal prominence moved upward and passed the sensor, and the second phase was obtained when laryngeal prominence returned to its initial position [22].…”