Toru Yabe

Coordination between respiration and swallowing during non-invasive positive pressure ventilation

The purpose of this study was to test the hypothesis that the risk of silent aspiration is increased in non‐invasive positive pressure ventilation.

Swallow-monitoring system with acoustic analysis for dysphagia

Dysphagia is a medical term for difficulty of swallowing. For these patients, silent aspiration or aspiration without coughing lead to aspiration pneumonia. Generally, Video Fluoroscopic (VF) swallow-testing is performed to evaluate swallowing movement. The purpose of VF is the detailed evaluation and diagnosis of dysphagia. Based on them, the examiner estimates how to approach for dysphagia, and provides appropriately adjusted food consistency. However, this testing has some serious problems that include X-ray exposure and lack of mobility, and so on. Therefore, this study proposes a nonrestrictive and noninvasive swallow-monitoring system using acoustic analysis. This system works on observation of swallowing and breathing, and detects swallowing based on acoustic frequency factors and respiratory flow. As a result, this study developed an algorism for swallowing detection with high specificity. Moreover, it is discussed and concluded on the findings associated with the frequency properties of swallowing and non-swallowing behaviors.

A knowledge-based approach to identify aspiration by fuzzy logic

Aspiration is associated with the decreased Quality of Life Score (QOLS) in swallowing and chewing. It is caused by central nervous system disorders that include stroke, cerebral palsy, and intractable neurological diseases, disorders of oral cavity, pharynx or larynx and so on. Because the simple aging causes ingesting/swallowing disorders, it became one of serious health problems of the aging society. The evaluation of dysphagia is used by video fluoroscopy (VF), video endoscopy (VE), repetitive saliva swallow test, water swallow tests, and food tests. The advantage of VF and VE is the detailed evaluation and diagnosis for it, and the disadvantage of them is a higher risk of carcinogenesis by X-rays. Therefore, the authors propose a noninvasive swallow testing system by fuzzy logic. This study developed a fuzzy system that permits flexible modeling using breath information and sound intensity. The results confirmed that the fuzzy inference method yields a high accurate swallow estimates of 84.75%.