Personalized optimal pillow shape and pneumatic smart pillow maintaining natural cervical curvature: a pilot study

An optimal pillow minimizes cervical symptoms. This study aims to investigate the personalized pillow shape involving body dimensions, and develop a shape-adjustable smart pillow. The optimal pillow shape, defined as best maintaining the natural standing cervical curvature in supine position, was evaluated among 14 subjects across varying pillow heights (4-10 cm) and neck support heights (flat-2 cm). Spearman correlation analysis verified significant positive monotonic associations between optimal pillow shape parameters and body dimensions, from which descriptive equations were derived. Muscle fatigue of optimal pillow was evaluated via electromyography of neck muscles on 7 subjects. Body height showed a significant positive monotonic association with optimal pillow height. Similarly, the ratio of body height to cervical eminence showed a significant positive monotonic association with optimal neck support height. This personalized pillow shape induced the highest median frequency slope in neck muscles. Pneumatic-driven smart pillow with adjustable pillow height and neck support height was subsequently developed for body dimension adaption, and the cervical curvatures in supine position were tested among 13 subjects. It exhibited superior ability in maintaining natural cervical curvature than latex pillow and polyester fiber pillow. In conclusion, body height and cervical eminence are associated with the optimal pillow shape for cervical curvature preservation. This pillow shape benefits relieving neck muscle fatigue. The developed smart pillow preserves physiological cervical curvature more effectively in the supine position than latex and polyester fiber pillows.