Introduction: Tongue strength reserve is the difference between the maximum isometric pressure (MIP) and swallowing pressure of the tongue. People with decreased tongue strength reserve may have a higher risk of presbyphagia or dysphagia. Thus, this study explored the effects of tongue strengthening exercise (TSE) on tongue strength reserve and detraining effects in healthy adults. Materials and Methods: In total, 102 healthy volunteers without any reported history of speech or swallowing deficits were recruited and assigned to experimental (n = 50) and control groups (n = 52). Exercises in the experimental group consisted of compressing an air-filled bulb between the tongue and hard palate for 30 min a day, 5 days a week, for 8 weeks. Thereafter, the experimental group underwent a 4-week detraining period. Results: Following the TSE training, posterior tongue strength reserve (F = 4.92, p = 0.029) of the experimental group was significantly higher than that of the control group. No significant detraining effects were observed on the MIP and swallowing pressure from 4 weeks after the completion of TSE training. Conclusions: According to the study results, TSE may be an effective approach for improving swallowing function.

Traditional door mechanisms in public spaces, such as knob locks and standard handles, require manual contact, making them prone to contamination and posing significant health risks. To address the critical need for a safer and more hygienic solution, this study aimed to develop an innovative foot-operated door mechanism that is accessible and intuitive for all users. The study applies the Theory of Inventive Problem Solving (TRIZ), ergonomic principles, and universal design to develop the foot-operated mechanism, while using Importance–Performance Analysis (IPA) and the Kano model to evaluate user satisfaction and identify design improvements. The foot-operated mechanism developed in this study features internal and external pedals for seamless door operation, a secure locking system, and color-coded indicators for clear occupancy status communication, ensuring both ease of use and privacy. The design significantly enhances hygiene by minimizing manual contact and improves user convenience, as confirmed through the IPA-Kano analysis. This mechanism not only provides a practical and effective solution to contamination risks but also demonstrates versatility, making it suitable for various public spaces and accessible to a wide range of users. This study represents a significant contribution to public infrastructure by providing a safer, more hygienic, and sustainable solution for door operation in public spaces.

This study presents the development of an innovative multifunctional cup holder designed to enhance safety, usability, and sustainability. Addressing common issues such as accidental spills, heat retention, and structural stability, the proposed design incorporates adjustable fixation and heating functionalities. The research applies a systematic design approach, applying the Theory of Inventive Problem Solving (TRIZ) methodology to resolve design contradictions and enhance product functionality. By integrating human factors considerations and universal design principles, the cup holder aims to improve user experience and accessibility. The design features a vacuum-based adjustable fixation system to prevent tipping, a controlled heating mechanism to maintain beverage temperature, and a shock-absorbing structure for enhanced durability. To evaluate whether the final design meets user expectations, a SERVQUAL questionnaire was used to collect user feedback, which was then analyzed using the Importance–Performance Analysis combined with the Kano model (IPA-Kano model). The results revealed an overall importance score of 4.347 and a satisfaction score of 3.943. Key strengths identified include reliable shock resistance, effective fixation, and ease of operation, while areas such as brand reputation and temperature control precision were found to require improvement due to their high importance but low performance. These insights confirm that the proposed design effectively enhances stability, thermal performance, and user convenience, while aligning with users’ expectations. By addressing critical functional and safety needs, this research advances the development of practical, user-centered innovations in everyday product design.