Validation of the optimal site in the neck region for detecting swallowing sounds

Mealcoach: Contact Microphone-Based Meal Supervision For Post-Stroke Dysphagia Patients

Meal supervision for post-stroke dysphagia patients significantly improves prognosis during rehabilitation. Aspiration often occurs during meals, which may further incur aspiration pneumonia. Therefore, it's necessary to know the patient's swallowing ability as well as the occurrence of cough. Recently, some researchers have detected swallowing or coughing with audio signals and have made remarkable achievements. However, the users need to stay in quiet environments or wear uncomfortable cervical auscultation devices because the signals generated by swallowing are weak. In this work, we present MealCoach, a system that utilizes a contact microphone to collect high-quality signals to identify the events during meals. We take advantage of the insensitivity of contact microphones to ambient noise for free-living environment supervision. After balancing the wearing experience and identification accuracy, we elaborately select the optimal site to leverage the unique characteristics of cricoid cartilage movement during meals to accurately identify swallowing, coughing, speaking, and other events during meals. We collected data from thirty PSD patients in the hospital and evaluated our system, and the results demonstrate that MealCoach achieves a mean classification accuracy of 95.4%.

Toward a robust swallowing detection for an implantable active artificial larynx: a survey

Total laryngectomy consists in the removal of the larynx and is intended as a curative treatment for laryngeal cancer, but it leaves the patient with no possibility to breathe, talk, and swallow normally anymore. A tracheostomy is created to restore breathing through the throat, but the aero-digestive tracts are permanently separated and the air no longer passes through the nasal tracts, which allowed filtration, warming, humidification, olfaction, and acceleration of the air for better tissue oxygenation. As for phonation restoration, various techniques allow the patient to talk again. The main one consists of a tracheo-esophageal valve prosthesis that makes the air passes from the esophagus to the pharynx, and makes the air vibrate to allow speech through articulation. Finally, swallowing is possible through the original tract as it is now isolated from the trachea. Yet, many methods exist to detect and assess a swallowing, but none is intended as a definitive restoration technique of the natural airway, which would permanently close the tracheostomy and avoid its adverse effects. In addition, these methods are non-invasive and lack detection accuracy. The feasibility of an effective early detection of swallowing would allow to further develop an implantable active artificial larynx and therefore restore the aero-digestive tracts. A previous attempt has been made on an artificial larynx implanted in 2012, but no active detection was included and the system was completely mechanic. This led to residues in the airway because of the imperfect sealing of the mechanism. An active swallowing detection coupled with indwelling measurements would thus likely add a significant reliability on such a system as it would allow to actively close an artificial larynx. So, after a brief explanation of the swallowing mechanism, this survey intends to first provide a detailed consideration of the anatomical region involved in swallowing, with a detection perspective. Second, the swallowing mechanism following total laryngectomy surgery is detailed. Third, the current non-invasive swallowing detection technique and their limitations are discussed. Finally, the previous points are explored with regard to the inherent requirements for the feasibility of an effective swallowing detection for an artificial larynx. Graphical Abstract.

The effects of neuromuscular joint facilitation treatment using neck patterns on the acoustic analysis of swallowing sounds in healthy adults

[Purpose] We aimed to investigate the changes in the swallowing sounds of healthy adults during neuromuscular joint facilitation treatment using neck patterns. [Participants and Methods] A total of 20 healthy adults (10 males and 10 females; mean age, 29.2 ± 6.3 years) swallowed 10 mL of water four times under three conditions (after the neuromuscular joint facilitation neck-flexion resistance pattern, after the Shaker-type exercise, and during relaxed sitting without prior exercise [control]), randomly ordered with an interval greater than 3 days. Swallowing sounds for each water swallow were recorded using cervical auscultation. [Results] The mean amplitude of swallowing sound intensity and the mean spectral frequency were significantly higher after the neuromuscular joint facilitation neck-flexion resistance pattern and the Shaker-type exercise, in comparison with those in the control group. [Conclusion] Neuromuscular joint facilitation training with the neck-flexion resistance pattern influenced swallowing sounds to the same degree as the Shaker-type exercise, implying that this resistance pattern may enhance suprahyoid muscle contraction.