A model-based approach for the analysis of aircraft seating comfort.

BACKGROUND: Aircraft seating comfort has a significant impact on passenger on-board experience. Its assessment requires the adoption of well-designed strategies for data collection as well as appropriate data analysis methods in order to obtain accurate and reliable results. OBJECTIVES: This paper focuses on the assessment of aircraft seating comfort based on subjective comfort responses collected during laboratory experiments and taking into account seat features and passenger characteristics. METHODS: The subjective comfort evaluations have been analyzed using a model-based approach to investigate the relationship between overall seating comfort and specific seat/user characteristics. RESULTS: The results show that the overall seating comfort perception is significantly influenced by the thickness of the seat pan, the backrest position (upright or reclined), the age of the passenger and the passenger perception of being comfortably supported at the lumbar region. CONCLUSIONS: The adopted model-based approach allows the analysis of subjective seating comfort data taking into account their ordinal nature as well as the dependency between evaluations provided by the same subject.

Design and analysis of comparative experiments to assess the (dis-)comfort of aircraft seating.

This paper focuses on the comparative assessment of comfort and discomfort (hereafter, (dis-)comfort) for aircraft seating. Subjective and objective data of seating (dis-)comfort were collected during an experiment involving 20 volunteers who tested 3 aircraft double-seats in upright and reclined position. In order to minimize experimental uncertainty due to well-known noise factors (i.e. patterns of discomfort during the work week and during the work day, order of evaluation, inter-individual differences), experimental trials were performed according to a crossover design. Statistical data analysis aimed mainly at investigating (dis-)comfort differences across seat conditions; gender-based differences in perceived discomfort on different body parts; effect of sitting duration on perceived discomfort on different body parts. The experimental results show that differences across seat conditions impacted differently on perceived discomfort depending on gender, body parts and sitting duration. No significant differences in perceived discomfort across gender were evident for the lightweight seat in both upright and reclined positions. On the contrary, for both baseline configurations, perceived discomfort at head and neck areas was higher for males than for females. For all seat conditions, participants experienced a significant worsening of perceived comfort over time at shoulders, back, sacrum and thighs and, in addition, at upper body area (i.e. neck, arm and forearm) and knees only for seats in reclined position.

The use of veritas collagen matrix to reconstruct the posterior chest wall after costovertebrectomy.

Among the new materials introduced for chest wall reconstruction, the use of collagen matrix is gaining increasing favor for its biomechanical properties. We describe the reconstruction of the chest wall with Veritas (Synovis, St Paul, MN) collagen matrix of a posterior chest wall defect after costovertebrectomy for Ewing's sarcoma. En bloc resection was performed, including partial D7 through D9 vertebrectomy along with the posterolateral segments of corresponding ribs. The collagen matrix patch was sutured to the spine stabilizer and the surrounding rib segments and was covered by previously raised latissimus dorsi and trapezius muscle flaps. Excellent stabilization was obtained.