Monitoring eating habits using a piezoelectric sensor-based necklace

Silanized aluminum borate whiskers (ABWs) of 4 wt%, silanized zirconium dioxide nanoparticles (nano-ZrO2) of 2 wt% were mixed with polymethyl methacrylate (PMMA) powder to get ZrO2-ABWs/PMMA composites. Titanium dioxide (TiO2), silver-supported titanium dioxide (Ag/TiO2), silver-supported zirconium phosphate (Novaron) and tetrapod-like zinc oxide whiskers (T-ZnOw) antibacterial agents of 3 wt% were mixed with ZrO2-ABWs/PMMA composites respectively to fabricate standard specimens. Plaque biofilms on the specimens surface were investigated for colony-forming units (CFUs). In addition, cytotoxicity and mechanical behavior were evaluated. Results showed that the CFUs values of S. mutans and C. albican biofilms on the four antibacterial composites surface were all reduced (p 0.05) except TiO2 and Ag/TiO2 groups of undiluted extracts. The flexural strength and surface hardness of Novaron and T-ZnOw groups were increased (p<0.05) compared to the control group.

https://www.jstage.jst.go.jp/article/dmj/36/6/36_2016-301/_pdf

Antibacterial activity, cytotoxicity and mechanical behavior of nano-enhanced denture base resin with different kinds of inorganic antibacterial agents.

Dysphagia (difficulty in swallowing) is an important issue in the elderly because it causes aspiration pneumonia, which is the second largest cause of death in this group. It also causes decline in activities of daily living and quality of life. The oral phase of swallowing has been neglected, despite its importance in the evaluation of dysphagia, because adequate protocols and measuring devices are unavailable. However, recent advances in sensor technology have enabled straightforward, non-invasive measurement of the movement of important swallowing-related organs such as the lips and tongue, as well as the larynx. In this article, we report the present state and possibility of clinical application of such systems developed in Japan.

https://www.mdpi.com/1424-8220/10/1/176/pdf

Recent advances in sensing oropharyngeal swallowing function in Japan.

Background 
Swallowing dysfunction (also known as dysphagia), which results in a deterioration of nutritional intake, slows rehabilitation and causes aspiration pneumonia, is very common following neurological impairments. Although videofluorographic (VF) examination is widely used for detecting aspiration, an objective and non-invasive method for assessing swallowing function has yet to be established because of a lack of adequate devices and protocols. In this paper, a bend sensor whose resistance is altered by bending was introduced to monitor swallowing-related laryngeal movement.
Methods 
Six healthy male volunteers were recruited in the present study. Specific time points on the signal waveform produced by the bend sensor were defined to describe laryngeal movement by differential analysis. Additionally, the physiological significance of the obtained waveform was confirmed by analyzing the sequential correlations between the signal waveform from the bend sensor and hyoid bone kinetics simultaneously recorded by VF.
Results 
Seven time points were successfully defined on the signal waveform to reference laryngeal movement. Each time point was well correlated with certain VF events, with evidence of no significant time lags, and there were positive correlations between waveform time points and matched VF events. Furthermore, obvious similarities were noticed between the duration of each phase on the signal waveform and the duration of the matched hyoid bone activity.
Conclusions 
The present monitoring system using a bend sensor might be useful for observing the temporal aspects of laryngeal movement during swallowing, and it was well coordinated with hyoid bone movement.

/pdf/development-of-a-system-to-monitor-laryngeal-movement-during-2f8rlf5xlx.pdf

Development of a System to Monitor Laryngeal Movement during Swallowing Using a Bend Sensor

Influences of bolus volumes on activity patterns of the suprahyoid muscles during swallowing were examined using the T(P) technique (which quantitatively evaluates muscle activity patterns and indicates a negatively skewed pattern at lower T(P) values) in healthy young adults (eight men and four women). One of six volumes of tea ranging from 10 to 32 mL was delivered randomly to each subject while recording an electromyogram of the suprahyoid muscles and a laryngeal mechanogram with a piezoelectric sensor. Each subject was asked to swallow the full volume of liquid in a gulp if possible. T(P) values were calculated as deciles from T(0) to T(100) during intervals that were defined by the trajectory of the laryngeal mechanogram recorded during swallowing. Seven significant differences were detected in the average T(P) values from T(30) to T(60): between 16 mL (e.g., 0.448 in T(30)) and 25 mL (0.408 in T(30)) and between 20 mL (0.453 in T(30)) and 25 mL. There were significant differences among the 12 subjects for all of the nine average T(P) values (Ps < 0.001), suggesting a notable intersubject variation in the suprahyoid (SH) activity patterns. The average peak amplitudes of the integrated suprahyoid activity differed significantly among the six volumes (P < 0.001), while the average durations measured by the laryngeal mechanogram did not. The present results suggest that the swallowing volume mainly affects SH activity patterns, which were evaluated by the T(P) technique, during the early period of each swallow.

Activity patterns of the suprahyoid muscles during swallowing of different fluid volumes.

A Relation Between the Piezoelectric Pulse Transducer Waveforms and Food Bolus Passage during Pharyngeal Phase of Swallow

Effects of low-energy electron beam irradiation on flexural properties of self-curing acrylic resin

doi: 101111/j1741-2358201100547x



Evaluation of newly developed devices for denture placement and removal in the dependent elderly



Objective:  The purpose of this study was to subjectively evaluate the utility of newly developed denture placement and removal devices Objective observations were also made to support the evidence



Materials and method:  Twenty-one subjects were instructed to place and remove their dentures with and without the devices We evaluated the device based on a questionnaire Objective observations were based on a 2-D image analysis We analysed three factors: the time, the area and the circumference required to insert and remove the dentures



Results:  Image analysis showed that the effectiveness and ease with which the subject used the device significantly improved with practice The questionnaire data showed that a majority of the subjects appreciated the device after the first and second time While there was no significant decrease in time required to place and remove dentures even with the device, the area and circumference of the movement on 2-D images were significantly reduced



Conclusion:  In this study, the utility of denture placement and removal devices was evaluated both subjectively and objectively Our data reveal that the device is effective in the elderly Further minor improvement in the device might be required to increase its effectiveness

https://onlinelibrary.wiley.com/doi/pdf/10.1111/j.1741-2358.2011.00547.x

Akiko Nomura

Papers

A Relation Between the Piezoelectric Pulse Transducer Waveforms and Food Bolus Passage during Pharyngeal Phase of Swallow

Effects of low-energy electron beam irradiation on flexural properties of self-curing acrylic resin

Evaluation of newly developed devices for denture placement and removal in the dependent elderly.